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f2e8fdb5f1eb0d8587604c35431ba5fa3c8efd3f
littlefs/lfs.c
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Christopher Haster f2e8fdb5f1 Changed insert tags to insert _after_ the current rid 
This atypical but not unreasonable behavior (most array insert functions
I've ran into like to insert _before_ the current index) makes split
commits no longer special behavior of appendattrs/commit, and seems to
fit better into rbyd append logic (though admittedly, some of the rbyd
append logic gets really weird with the whole right-leaning business).

Though this does come with a couple downsides:

- All rbyd-based data structures need to be able to represent a -1 id
  so we can insert into the first id. This is not a problems for
  rids/bids, but we need to tweak mids to support mid.rid=-1.

  The best solution I could come up with was to just increment rid by
  one, so, assuming mbits=8:

  - mid=0x100 => bid=0x100, rid=-1
  - mid=0x101 => bid=0x100, rid=0
  - mid=-1    => bid=-1,    rid=-1

- We need to be really careful with splits over our attr-list, since
  these can line up between the rid create tags reference and other
  following tags intended to stick to the new rid.

  This required some special handling in lfsr_rbyd_appendattrs and
  lfsr_mdir_commit__.

Other than that this change is quite promising, and removed what felt
like a bunch of hacks adjusting mids in lfsr_file_carve.

            code          stack
  before:  33992           2904
  after:   33868 (-0.4%)   2896 (-0.3%)
2024-02-03 18:16:58 -06:00

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/*
* The little filesystem
*
* Copyright (c) 2022, The littlefs authors.
* Copyright (c) 2017, Arm Limited. All rights reserved.
* SPDX-License-Identifier: BSD-3-Clause
*/
#include "lfs.h"
#include "lfs_util.h"
// TODO do we still need these?
// some constants used throughout the code
#define LFS_BLOCK_NULL ((lfs_block_t)-1)
#define LFS_BLOCK_INLINE ((lfs_block_t)-2)
// TODO do we still need these?
enum {
LFS_OK_RELOCATED = 1,
LFS_OK_DROPPED = 2,
LFS_OK_ORPHANED = 3,
};
// a normal compare enum, but shifted up by one to allow unioning with
// negative error codes
enum {
LFS_CMP_LT = 0,
LFS_CMP_EQ = 1,
LFS_CMP_GT = 2,
};
typedef int lfs_scmp_t;
static inline int lfs_cmp(lfs_scmp_t cmp) {
return cmp - 1;
}
/// Caching block device operations ///
static inline void lfs_cache_drop(lfs_t *lfs, lfs_cache_t *rcache) {
// do not zero, cheaper if cache is readonly or only going to be
// written with identical data (during relocates)
(void)lfs;
rcache->block = LFS_BLOCK_NULL;
}
static inline void lfs_cache_zero(lfs_t *lfs, lfs_cache_t *pcache) {
// zero to avoid information leak
memset(pcache->buffer, 0xff, lfs->cfg->cache_size);
pcache->block = LFS_BLOCK_NULL;
}
static int lfs_bd_read(lfs_t *lfs,
const lfs_cache_t *pcache, lfs_cache_t *rcache, lfs_size_t hint,
lfs_block_t block, lfs_size_t off,
void *buffer, lfs_size_t size) {
uint8_t *data = buffer;
if (block >= lfs->cfg->block_count ||
off+size > lfs->cfg->block_size) {
return LFS_ERR_CORRUPT;
}
while (size > 0) {
lfs_size_t diff = size;
if (pcache && block == pcache->block &&
off < pcache->off + pcache->size) {
if (off >= pcache->off) {
// is already in pcache?
diff = lfs_min(diff, pcache->size - (off-pcache->off));
memcpy(data, &pcache->buffer[off-pcache->off], diff);
data += diff;
off += diff;
size -= diff;
continue;
}
// pcache takes priority
diff = lfs_min(diff, pcache->off-off);
}
if (block == rcache->block &&
off < rcache->off + rcache->size) {
if (off >= rcache->off) {
// is already in rcache?
diff = lfs_min(diff, rcache->size - (off-rcache->off));
memcpy(data, &rcache->buffer[off-rcache->off], diff);
data += diff;
off += diff;
size -= diff;
continue;
}
// rcache takes priority
diff = lfs_min(diff, rcache->off-off);
}
if (size >= hint && off % lfs->cfg->read_size == 0 &&
size >= lfs->cfg->read_size) {
// bypass cache?
diff = lfs_aligndown(diff, lfs->cfg->read_size);
int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
if (err) {
return err;
}
// TODO this was a quick hack, the entire cache system probably
// requires a deeper look
//
// fix overlaps with our pcache
if (pcache
&& block == pcache->block
&& off < pcache->off + pcache->size
&& off + diff > pcache->off) {
lfs_size_t off_ = lfs_max(off, pcache->off);
lfs_size_t diff_ = lfs_min(
diff - (off_-off),
pcache->size - (off_-pcache->off));
memcpy(&data[off_-off],
&pcache->buffer[off_-pcache->off],
diff_);
}
data += diff;
off += diff;
size -= diff;
continue;
}
// load to cache, first condition can no longer fail
LFS_ASSERT(block < lfs->cfg->block_count);
rcache->block = block;
rcache->off = lfs_aligndown(off, lfs->cfg->read_size);
rcache->size = lfs_min(
lfs_min(
lfs_alignup(off+lfs_max(size, hint), lfs->cfg->read_size),
lfs->cfg->block_size)
- rcache->off,
lfs->cfg->cache_size);
int err = lfs->cfg->read(lfs->cfg, rcache->block,
rcache->off, rcache->buffer, rcache->size);
LFS_ASSERT(err <= 0);
if (err) {
return err;
}
// TODO this was a quick hack, the entire cache system probably
// requires a deeper look
//
// fix overlaps with our pcache
if (pcache
&& rcache->block == pcache->block
&& rcache->off < pcache->off + pcache->size
&& rcache->off + rcache->size > pcache->off) {
lfs_size_t off_ = lfs_max(rcache->off, pcache->off);
lfs_size_t size_ = lfs_min(
rcache->size - (off_-rcache->off),
pcache->size - (off_-pcache->off));
memcpy(&rcache->buffer[off_-rcache->off],
&pcache->buffer[off_-pcache->off],
size_);
}
}
return 0;
}
static int lfs_bd_cmp(lfs_t *lfs,
const lfs_cache_t *pcache, lfs_cache_t *rcache, lfs_size_t hint,
lfs_block_t block, lfs_size_t off,
const void *buffer, lfs_size_t size) {
const uint8_t *data = buffer;
lfs_size_t diff = 0;
// make sure our hint is at least as big as our buffer
hint = lfs_max(hint, size);
for (lfs_size_t i = 0; i < size; i += diff) {
uint8_t dat[8];
diff = lfs_min(size-i, sizeof(dat));
int err = lfs_bd_read(lfs,
pcache, rcache, hint-i,
block, off+i, &dat, diff);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
int res = memcmp(dat, data + i, diff);
if (res) {
return (res < 0) ? LFS_CMP_LT : LFS_CMP_GT;
}
}
return LFS_CMP_EQ;
}
//static int lfs_bd_crc(lfs_t *lfs,
// const lfs_cache_t *pcache, lfs_cache_t *rcache, lfs_size_t hint,
// lfs_block_t block, lfs_off_t off, lfs_size_t size, uint32_t *crc) {
// lfs_size_t diff = 0;
//
// for (lfs_off_t i = 0; i < size; i += diff) {
// uint8_t dat[8];
// diff = lfs_min(size-i, sizeof(dat));
// int err = lfs_bd_read(lfs,
// pcache, rcache, hint-i,
// block, off+i, &dat, diff);
// if (err) {
// return err;
// }
//
// *crc = lfs_crc(*crc, &dat, diff);
// }
//
// return 0;
//}
static int lfs_bd_crc32c(lfs_t *lfs,
const lfs_cache_t *pcache, lfs_cache_t *rcache, lfs_size_t hint,
lfs_block_t block, lfs_size_t off, lfs_size_t size, uint32_t *crc) {
lfs_size_t diff = 0;
for (lfs_size_t i = 0; i < size; i += diff) {
uint8_t dat[8];
diff = lfs_min(size-i, sizeof(dat));
int err = lfs_bd_read(lfs,
pcache, rcache, lfs_max32(hint, size)-i,
block, off+i, &dat, diff);
if (err) {
return err;
}
*crc = lfs_crc32c(*crc, &dat, diff);
}
return 0;
}
#ifndef LFS_READONLY
static int lfs_bd_flush(lfs_t *lfs,
lfs_cache_t *pcache, lfs_cache_t *rcache, bool validate,
uint32_t *flcksum_) {
if (pcache->block != LFS_BLOCK_NULL && pcache->block != LFS_BLOCK_INLINE) {
LFS_ASSERT(pcache->block < lfs->cfg->block_count);
lfs_size_t diff = lfs_alignup(pcache->size, lfs->cfg->prog_size);
int err = lfs->cfg->prog(lfs->cfg, pcache->block,
pcache->off, pcache->buffer, diff);
LFS_ASSERT(err <= 0);
if (err) {
return err;
}
if (validate) {
// check data on disk
lfs_cache_drop(lfs, rcache);
lfs_scmp_t cmp = lfs_bd_cmp(lfs,
NULL, rcache, diff,
pcache->block, pcache->off, pcache->buffer, diff);
if (cmp < 0) {
return cmp;
}
if (lfs_cmp(cmp) != 0) {
return LFS_ERR_CORRUPT;
}
}
// this is when we update the the flushed checksum if requested
if (flcksum_) {
*flcksum_ = lfs_crc32c(*flcksum_,
pcache->buffer, pcache->size);
}
lfs_cache_zero(lfs, pcache);
}
return 0;
}
#endif
#ifndef LFS_READONLY
static int lfs_bd_sync(lfs_t *lfs,
lfs_cache_t *pcache, lfs_cache_t *rcache, bool validate) {
lfs_cache_drop(lfs, rcache);
int err = lfs_bd_flush(lfs, pcache, rcache, validate, NULL);
if (err) {
return err;
}
err = lfs->cfg->sync(lfs->cfg);
LFS_ASSERT(err <= 0);
return err;
}
#endif
#ifndef LFS_READONLY
static int lfs_bd_prog(lfs_t *lfs,
lfs_cache_t *pcache, lfs_cache_t *rcache, bool validate,
lfs_block_t block, lfs_size_t off,
const void *buffer, lfs_size_t size,
uint32_t *flcksum_) {
const uint8_t *data = buffer;
LFS_ASSERT(block == LFS_BLOCK_INLINE || block < lfs->cfg->block_count);
LFS_ASSERT(off + size <= lfs->cfg->block_size);
// update rcache if we overlap
if (rcache
&& block == rcache->block
&& off < rcache->off + rcache->size
&& off + size > rcache->off) {
lfs_size_t off_ = lfs_max(off, rcache->off);
lfs_size_t size_ = lfs_min(
size - (off_-off),
rcache->size - (off_-rcache->off));
memcpy(&rcache->buffer[off_-rcache->off], &data[off_-off], size_);
}
while (size > 0) {
if (block == pcache->block &&
off >= pcache->off &&
off < pcache->off + lfs->cfg->cache_size) {
// already fits in pcache?
lfs_size_t diff = lfs_min(size,
lfs->cfg->cache_size - (off-pcache->off));
memcpy(&pcache->buffer[off-pcache->off], data, diff);
data += diff;
off += diff;
size -= diff;
pcache->size = lfs_max(pcache->size, off - pcache->off);
if (pcache->size == lfs->cfg->cache_size) {
// eagerly flush out pcache if we fill up
int err = lfs_bd_flush(lfs, pcache, rcache, validate,
flcksum_);
if (err) {
return err;
}
}
continue;
}
// prepare pcache, first condition can no longer fail
lfs_cache_zero(lfs, pcache);
pcache->block = block;
pcache->off = lfs_aligndown(off, lfs->cfg->prog_size);
pcache->size = 0;
}
return 0;
}
#endif
#ifndef LFS_READONLY
static int lfs_bd_erase(lfs_t *lfs, lfs_block_t block) {
LFS_ASSERT(block < lfs->cfg->block_count);
// make sure any caches are outdated appropriately here
if (lfs->rcache.block == block) {
lfs_cache_drop(lfs, &lfs->rcache);
}
int err = lfs->cfg->erase(lfs->cfg, block);
LFS_ASSERT(err <= 0);
return err;
}
#endif
// TODO should these be the only bd APIs?
// simpler APIs if assume file caches are irrelevant
//
// note hint has two convenience:
// 1. 0 = minimal caching
// 2. block_size = maximal caching
//
static int lfsr_bd_read(lfs_t *lfs,
lfs_block_t block, lfs_size_t off, lfs_size_t hint,
void *buffer, lfs_size_t size) {
// check for in-bounds
if (off+size > lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
return lfs_bd_read(lfs, &lfs->pcache, &lfs->rcache, hint,
block, off, buffer, size);
}
// TODO merge lfsr_bd_readcksum/lfsr_bd_cksum somehow?
static int lfsr_bd_readcksum(lfs_t *lfs,
lfs_block_t block, lfs_size_t off, lfs_size_t hint,
void *buffer, lfs_size_t size,
uint32_t *cksum_) {
int err = lfsr_bd_read(lfs, block, off, hint, buffer, size);
if (err) {
return err;
}
*cksum_ = lfs_crc32c(*cksum_, buffer, size);
return 0;
}
static int lfsr_bd_cksum(lfs_t *lfs,
lfs_block_t block, lfs_size_t off, lfs_size_t hint, lfs_size_t size,
uint32_t *cksum_) {
// check for in-bounds
if (off+size > lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
return lfs_bd_crc32c(lfs, &lfs->pcache, &lfs->rcache, hint,
block, off, size, cksum_);
}
static lfs_scmp_t lfsr_bd_cmp(lfs_t *lfs,
lfs_block_t block, lfs_size_t off, lfs_size_t hint,
const void *buffer, lfs_size_t size) {
// check for in-bounds
if (off+size > lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
return lfs_bd_cmp(lfs, &lfs->pcache, &lfs->rcache, hint,
block, off, buffer, size);
}
// program data with optional checksum
static int lfsr_bd_prog(lfs_t *lfs, lfs_block_t block, lfs_size_t off,
const void *buffer, lfs_size_t size,
uint32_t *cksum_, uint32_t *flcksum_) {
// check for in-bounds
if (off+size > lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
int err = lfs_bd_prog(lfs, &lfs->pcache, &lfs->rcache, false,
block, off, buffer, size,
flcksum_);
if (err) {
return err;
}
// optional checksum
if (cksum_) {
*cksum_ = lfs_crc32c(*cksum_, buffer, size);
}
return 0;
}
static int lfsr_bd_flush(lfs_t *lfs,
uint32_t *flcksum_) {
return lfs_bd_flush(lfs, &lfs->pcache, &lfs->rcache, false,
flcksum_);
}
static int lfsr_bd_sync(lfs_t *lfs) {
return lfs_bd_sync(lfs, &lfs->pcache, &lfs->rcache, false);
}
// TODO do we need this? should everything be checked by crc and validation
// be an optional ifdef?
static int lfsr_bd_progvalidate(lfs_t *lfs, lfs_block_t block, lfs_size_t off,
const void *buffer, lfs_size_t size,
uint32_t *cksum_, uint32_t *flcksum_) {
// check for in-bounds
if (off+size > lfs->cfg->block_size) {
lfs_cache_zero(lfs, &lfs->pcache);
return LFS_ERR_RANGE;
}
int err = lfs_bd_prog(lfs, &lfs->pcache, &lfs->rcache, true,
block, off, buffer, size,
flcksum_);
if (err) {
return err;
}
// optional checksum
if (cksum_) {
*cksum_ = lfs_crc32c(*cksum_, buffer, size);
}
return 0;
}
static int lfsr_bd_syncvalidate(lfs_t *lfs) {
return lfs_bd_sync(lfs, &lfs->pcache, &lfs->rcache, true);
}
static int lfsr_bd_erase(lfs_t *lfs, lfs_block_t block) {
return lfs_bd_erase(lfs, block);
}
/// Small type-level utilities ///
//// operations on block pairs
//static inline void lfs_pair_swap(lfs_block_t pair[2]) {
// lfs_block_t t = pair[0];
// pair[0] = pair[1];
// pair[1] = t;
//}
//
//static inline bool lfs_pair_isnull(const lfs_block_t pair[2]) {
// return pair[0] == LFS_BLOCK_NULL || pair[1] == LFS_BLOCK_NULL;
//}
//
//static inline int lfs_pair_cmp(
// const lfs_block_t paira[2],
// const lfs_block_t pairb[2]) {
// return !(paira[0] == pairb[0] || paira[1] == pairb[1] ||
// paira[0] == pairb[1] || paira[1] == pairb[0]);
//}
//
//static inline bool lfs_pair_issync(
// const lfs_block_t paira[2],
// const lfs_block_t pairb[2]) {
// return (paira[0] == pairb[0] && paira[1] == pairb[1]) ||
// (paira[0] == pairb[1] && paira[1] == pairb[0]);
//}
//
//static inline void lfs_pair_fromle32(lfs_block_t pair[2]) {
// pair[0] = lfs_fromle32(pair[0]);
// pair[1] = lfs_fromle32(pair[1]);
//}
//
//#ifndef LFS_READONLY
//static inline void lfs_pair_tole32(lfs_block_t pair[2]) {
// pair[0] = lfs_tole32(pair[0]);
// pair[1] = lfs_tole32(pair[1]);
//}
//#endif
//
//// operations on 32-bit entry tags
//typedef uint32_t lfs_tag_t;
//typedef int32_t lfs_stag_t;
//
//#define LFS_MKTAG(type, id, size)
// (((lfs_tag_t)(type) << 20) | ((lfs_tag_t)(id) << 10) | (lfs_tag_t)(size))
//
//#define LFS_MKTAG_IF(cond, type, id, size)
// ((cond) ? LFS_MKTAG(type, id, size) : LFS_MKTAG(LFS_FROM_NOOP, 0, 0))
//
//#define LFS_MKTAG_IF_ELSE(cond, type1, id1, size1, type2, id2, size2)
// ((cond) ? LFS_MKTAG(type1, id1, size1) : LFS_MKTAG(type2, id2, size2))
//
//static inline bool lfs_tag_isvalid(lfs_tag_t tag) {
// return !(tag & 0x80000000);
//}
//
//static inline bool lfs_tag_isdelete(lfs_tag_t tag) {
// return ((int32_t)(tag << 22) >> 22) == -1;
//}
//
//static inline uint16_t lfs_tag_type1(lfs_tag_t tag) {
// return (tag & 0x70000000) >> 20;
//}
//
//static inline uint16_t lfs_tag_type2(lfs_tag_t tag) {
// return (tag & 0x78000000) >> 20;
//}
//
//static inline uint16_t lfs_tag_type3(lfs_tag_t tag) {
// return (tag & 0x7ff00000) >> 20;
//}
//
//static inline uint8_t lfs_tag_chunk(lfs_tag_t tag) {
// return (tag & 0x0ff00000) >> 20;
//}
//
//static inline int8_t lfs_tag_splice(lfs_tag_t tag) {
// return (int8_t)lfs_tag_chunk(tag);
//}
//
//static inline uint16_t lfs_tag_id(lfs_tag_t tag) {
// return (tag & 0x000ffc00) >> 10;
//}
//
//static inline lfs_size_t lfs_tag_size(lfs_tag_t tag) {
// return tag & 0x000003ff;
//}
//
//static inline lfs_size_t lfs_tag_dsize(lfs_tag_t tag) {
// return sizeof(tag) + lfs_tag_size(tag + lfs_tag_isdelete(tag));
//}
// 16-bit metadata tags
enum lfsr_tag {
// the null tag is reserved
LFSR_TAG_NULL = 0x0000,
// config tags
LFSR_TAG_CONFIG = 0x0000,
LFSR_TAG_MAGIC = 0x0003,
LFSR_TAG_VERSION = 0x0004,
LFSR_TAG_OCOMPATFLAGS = 0x0005,
LFSR_TAG_RCOMPATFLAGS = 0x0006,
LFSR_TAG_WCOMPATFLAGS = 0x0007,
LFSR_TAG_BLOCKSIZE = 0x0008,
LFSR_TAG_BLOCKCOUNT = 0x0009,
LFSR_TAG_NAMELIMIT = 0x000a,
LFSR_TAG_SIZELIMIT = 0x000b,
// global-state tags
LFSR_TAG_GDELTA = 0x0100,
LFSR_TAG_GRMDELTA = 0x0100,
// name tags
LFSR_TAG_NAME = 0x0200,
LFSR_TAG_REG = 0x0201,
LFSR_TAG_DIR = 0x0202,
LFSR_TAG_ORPHAN = 0x0203,
LFSR_TAG_BOOKMARK = 0x0204,
// struct tags
LFSR_TAG_STRUCT = 0x0300,
LFSR_TAG_DATA = 0x0300,
LFSR_TAG_BLOCK = 0x0304,
LFSR_TAG_BSHRUB = 0x0308,
LFSR_TAG_BTREE = 0x030c,
LFSR_TAG_DID = 0x0310,
LFSR_TAG_BECKSUM = 0x0314,
LFSR_TAG_BRANCH = 0x031c,
LFSR_TAG_MROOT = 0x0321,
LFSR_TAG_MDIR = 0x0325,
LFSR_TAG_MTREE = 0x032c,
// user/sys attributes
LFSR_TAG_UATTR = 0x0400,
LFSR_TAG_SATTR = 0x0600,
// shrub tags belong to secondary trees
LFSR_TAG_SHRUB = 0x1000,
// alt pointers form the inner nodes of our rbyd trees
LFSR_TAG_ALT = 0x4000,
LFSR_TAG_LE = 0x0000,
LFSR_TAG_GT = 0x2000,
LFSR_TAG_B = 0x0000,
LFSR_TAG_R = 0x1000,
// checksum tags
LFSR_TAG_CKSUM = 0x3000,
LFSR_TAG_ECKSUM = 0x3100,
// in-device only tags, these should never get written to disk
LFSR_TAG_INTERNAL = 0x0800,
LFSR_TAG_GRM = 0x0800,
LFSR_TAG_MOVE = 0x0801,
LFSR_TAG_SHRUBALLOC = 0x0802,
LFSR_TAG_SHRUBCOMMIT = 0x0803,
LFSR_TAG_SHRUBTRUNK = 0x0804,
// some in-device only tag modifiers
LFSR_TAG_RM = 0x8000,
LFSR_TAG_GROW = 0x4000,
LFSR_TAG_SUPMASK = 0x2000,
LFSR_TAG_SUBMASK = 0x1000,
// lfsr_rbyd_appendattr specific flags, also in-device only
LFSR_TAG_DIVERGED = 0x4000,
LFSR_TAG_DIVERGEDUPPER = 0x2000,
LFSR_TAG_DIVERGEDLOWER = 0x0000,
};
// LFSR_TAG_TAG just provides and escape hatch to pass raw tags
// through the LFSR_ATTR macro
#define LFSR_TAG_TAG(tag) (tag)
// some tag modifiers
#define LFSR_TAG_SHRUB(tag) (LFSR_TAG_SHRUB | LFSR_TAG_##tag)
#define LFSR_TAG_RM(tag) (LFSR_TAG_RM | LFSR_TAG_##tag)
#define LFSR_TAG_GROW(tag) (LFSR_TAG_GROW | LFSR_TAG_##tag)
#define LFSR_TAG_SUPMASK(tag) (LFSR_TAG_SUPMASK | LFSR_TAG_##tag)
#define LFSR_TAG_SUBMASK(tag) (LFSR_TAG_SUBMASK | LFSR_TAG_##tag)
// some other tag encodings with their own subfields
#define LFSR_TAG_ALT(d, c, key) \
(LFSR_TAG_ALT \
| LFSR_TAG_##d \
| LFSR_TAG_##c \
| (0x0fff & (lfsr_tag_t)(key)))
#define LFSR_TAG_UATTR(attr) \
(LFSR_TAG_UATTR \
| ((0x80 & (lfsr_tag_t)(attr)) << 1) \
| (0x7f & (lfsr_tag_t)(attr)))
#define LFSR_TAG_SATTR(attr) \
(LFSR_TAG_SATTR \
| ((0x80 & (lfsr_tag_t)(attr)) << 1) \
| (0x7f & (lfsr_tag_t)(attr)))
// tag type operations
static inline lfsr_tag_t lfsr_tag_mode(lfsr_tag_t tag) {
return tag & 0xf000;
}
static inline lfsr_tag_t lfsr_tag_suptype(lfsr_tag_t tag) {
return tag & 0xff00;
}
static inline uint8_t lfsr_tag_subtype(lfsr_tag_t tag) {
return tag & 0x00ff;
}
static inline lfsr_tag_t lfsr_tag_key(lfsr_tag_t tag) {
return tag & 0x0fff;
}
static inline lfsr_tag_t lfsr_tag_supkey(lfsr_tag_t tag) {
return tag & 0x0f00;
}
static inline lfsr_tag_t lfsr_tag_subkey(lfsr_tag_t tag) {
return tag & 0x00ff;
}
static inline bool lfsr_tag_isalt(lfsr_tag_t tag) {
return tag & LFSR_TAG_ALT;
}
static inline bool lfsr_tag_isshrub(lfsr_tag_t tag) {
return tag & LFSR_TAG_SHRUB;
}
static inline bool lfsr_tag_istrunk(lfsr_tag_t tag) {
return lfsr_tag_mode(tag) != LFSR_TAG_CKSUM;
}
static inline bool lfsr_tag_isinternal(lfsr_tag_t tag) {
return tag & LFSR_TAG_INTERNAL;
}
static inline bool lfsr_tag_isrm(lfsr_tag_t tag) {
return tag & LFSR_TAG_RM;
}
static inline bool lfsr_tag_isgrow(lfsr_tag_t tag) {
return tag & LFSR_TAG_GROW;
}
static inline bool lfsr_tag_issupwide(lfsr_tag_t tag) {
return tag & LFSR_TAG_SUPMASK;
}
static inline bool lfsr_tag_issubwide(lfsr_tag_t tag) {
return tag & LFSR_TAG_SUBMASK;
}
// lfsr_rbyd_appendattr diverged specific flags
static inline bool lfsr_tag_hasdiverged(lfsr_tag_t tag) {
return tag & LFSR_TAG_DIVERGED;
}
static inline bool lfsr_tag_isdivergedupper(lfsr_tag_t tag) {
return tag & LFSR_TAG_DIVERGEDUPPER;
}
static inline bool lfsr_tag_isdivergedlower(lfsr_tag_t tag) {
return !(tag & LFSR_TAG_DIVERGEDUPPER);
}
// alt operations
static inline bool lfsr_tag_isblack(lfsr_tag_t tag) {
return !(tag & LFSR_TAG_R);
}
static inline bool lfsr_tag_isred(lfsr_tag_t tag) {
return tag & LFSR_TAG_R;
}
static inline bool lfsr_tag_isle(lfsr_tag_t tag) {
return !(tag & LFSR_TAG_GT);
}
static inline bool lfsr_tag_isgt(lfsr_tag_t tag) {
return tag & LFSR_TAG_GT;
}
static inline lfsr_tag_t lfsr_tag_isparallel(lfsr_tag_t a, lfsr_tag_t b) {
return (a & LFSR_TAG_GT) == (b & LFSR_TAG_GT);
}
static inline bool lfsr_tag_follow(
lfsr_tag_t alt, lfsr_rid_t weight,
lfsr_srid_t lower, lfsr_srid_t upper,
lfsr_srid_t rid, lfsr_tag_t tag) {
if (lfsr_tag_isgt(alt)) {
return rid > upper - (lfsr_srid_t)weight - 1
|| (rid == upper - (lfsr_srid_t)weight - 1
&& lfsr_tag_key(tag) > lfsr_tag_key(alt));
} else {
return rid < lower + (lfsr_srid_t)weight - 1
|| (rid == lower + (lfsr_srid_t)weight - 1
&& lfsr_tag_key(tag) <= lfsr_tag_key(alt));
}
}
static inline bool lfsr_tag_follow2(
lfsr_tag_t alt, lfsr_rid_t weight,
lfsr_tag_t alt2, lfsr_rid_t weight2,
lfsr_srid_t lower, lfsr_srid_t upper,
lfsr_srid_t rid, lfsr_tag_t tag) {
if (lfsr_tag_isred(alt2) && lfsr_tag_isparallel(alt, alt2)) {
weight += weight2;
}
return lfsr_tag_follow(alt, weight, lower, upper, rid, tag);
}
static inline bool lfsr_tag_prune2(
lfsr_tag_t alt, lfsr_rid_t weight,
lfsr_tag_t alt2, lfsr_rid_t weight2,
lfsr_srid_t lower_rid, lfsr_srid_t upper_rid,
lfsr_tag_t lower_tag, lfsr_tag_t upper_tag) {
if (lfsr_tag_isgt(alt)) {
return lfsr_tag_follow2(
alt, weight,
alt2, weight2,
lower_rid, upper_rid,
lower_rid-1, lower_tag);
} else {
return lfsr_tag_follow2(
alt, weight,
alt2, weight2,
lower_rid, upper_rid,
upper_rid-1, upper_tag-1);
}
}
static inline void lfsr_tag_flip(
lfsr_tag_t *alt, lfsr_rid_t *weight,
lfsr_srid_t lower, lfsr_srid_t upper) {
*alt = *alt ^ LFSR_TAG_GT;
*weight = (upper - lower) - *weight;
}
static inline void lfsr_tag_flip2(
lfsr_tag_t *alt, lfsr_rid_t *weight,
lfsr_tag_t alt2, lfsr_rid_t weight2,
lfsr_srid_t lower, lfsr_srid_t upper) {
if (lfsr_tag_isred(alt2)) {
*weight += weight2;
}
lfsr_tag_flip(alt, weight, lower, upper);
}
static inline void lfsr_tag_trim(
lfsr_tag_t alt, lfsr_rid_t weight,
lfsr_srid_t *lower_rid, lfsr_srid_t *upper_rid,
lfsr_tag_t *lower_tag, lfsr_tag_t *upper_tag) {
if (lfsr_tag_isgt(alt)) {
*upper_rid -= weight;
if (upper_tag) {
*upper_tag = alt + 1;
}
} else {
*lower_rid += weight;
if (lower_tag) {
*lower_tag = alt + 1;
}
}
}
static inline void lfsr_tag_trim2(
lfsr_tag_t alt, lfsr_rid_t weight,
lfsr_tag_t alt2, lfsr_rid_t weight2,
lfsr_srid_t *lower_rid, lfsr_srid_t *upper_rid,
lfsr_tag_t *lower_tag, lfsr_tag_t *upper_tag) {
if (lfsr_tag_isred(alt2)) {
lfsr_tag_trim(alt2, weight2,
lower_rid, upper_rid,
lower_tag, upper_tag);
}
lfsr_tag_trim(alt, weight,
lower_rid, upper_rid,
lower_tag, upper_tag);
}
// support for encoding/decoding tags on disk
// each piece of metadata in an rbyd tree is prefixed with a 4-piece tag:
//
// - 8-bit suptype => 1 byte
// - 8-bit subtype => 1 byte
// - 32-bit rid/weight => 5 byte leb128 (worst case)
// - 32-bit size/jump => 5 byte leb128 (worst case)
// => 12 bytes total
//
#define LFSR_TAG_DSIZE (2+5+5)
static lfs_ssize_t lfsr_bd_readtag(lfs_t *lfs,
lfs_block_t block, lfs_size_t off, lfs_size_t hint,
lfsr_tag_t *tag_, lfsr_rid_t *weight_, lfs_size_t *size_,
uint32_t *cksum_) {
// read the largest possible tag size
uint8_t tag_buf[LFSR_TAG_DSIZE];
lfs_size_t tag_dsize = lfs_min32(LFSR_TAG_DSIZE, lfs->cfg->block_size-off);
int err = lfsr_bd_read(lfs, block, off, hint, &tag_buf, tag_dsize);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
if (tag_dsize < 2) {
return LFS_ERR_CORRUPT;
}
lfsr_tag_t tag
= ((lfsr_tag_t)tag_buf[0] << 8)
| ((lfsr_tag_t)tag_buf[1] << 0);
lfs_ssize_t d = 2;
if (cksum_) {
// on-disk, the tags valid bit must reflect the parity of the
// preceding data, fortunately for crc32c, this is the same as the
// parity of the crc
//
// note we need to do this before leb128 decoding as we may not have
// valid leb128 if we're erased, but we shouldn't treat a truncated
// leb128 here as corruption
if ((tag >> 15) != (lfs_popc(*cksum_) & 1)) {
return LFS_ERR_INVAL;
}
}
lfsr_srid_t weight;
lfs_ssize_t d_ = lfs_fromleb128(&weight, &tag_buf[d], tag_dsize-d);
if (d_ < 0) {
return d_;
}
d += d_;
lfs_ssize_t size;
d_ = lfs_fromleb128(&size, &tag_buf[d], tag_dsize-d);
if (d_ < 0) {
return d_;
}
d += d_;
// optional checksum
if (cksum_) {
*cksum_ = lfs_crc32c(*cksum_, tag_buf, d);
}
// save what we found, clearing the valid bit from the tag, note we
// checked this earlier
*tag_ = tag & 0x7fff;
*weight_ = weight;
*size_ = size;
return d;
}
static lfs_ssize_t lfsr_bd_progtag(lfs_t *lfs,
lfs_block_t block, lfs_size_t off,
lfsr_tag_t tag, lfsr_rid_t weight, lfs_size_t size,
uint32_t *cksum_) {
// check for underflow issues
LFS_ASSERT(weight < 0x80000000);
LFS_ASSERT(size < 0x80000000);
// bit 7 is reserved for future subtype extensions
LFS_ASSERT(!(tag & 0x80));
// make sure to include the parity of the current crc
tag |= (lfs_popc(*cksum_) & 1) << 15;
// encode into a be16 and pair of leb128s
uint8_t tag_buf[LFSR_TAG_DSIZE];
tag_buf[0] = (uint8_t)(tag >> 8);
tag_buf[1] = (uint8_t)(tag >> 0);
lfs_ssize_t d = 2;
lfs_ssize_t d_ = lfs_toleb128(weight, &tag_buf[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfs_toleb128(size, &tag_buf[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
int err = lfsr_bd_prog(lfs, block, off, &tag_buf, d,
cksum_, NULL);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
return d;
}
/// lfsr_data_t stuff ///
// data uses the size's sign bit to indicate on-disk vs in-device
#define LFSR_DATA_ONDISK 0x80000000
// in-device data modes
enum {
LFSR_DATA_BUF = 0,
LFSR_DATA_IMM = 1,
LFSR_DATA_CAT = 2,
};
// LFSR_DATA_DATA just provides and escape hatch to pass raw datas
// through the LFSR_ATTR macro
#define LFSR_DATA_DATA(_data) (_data)
#define LFSR_DATA_NULL() \
((lfsr_data_t){ \
.u.buf.size=0, \
.u.buf.mode=LFSR_DATA_BUF, \
.u.buf.buffer=NULL})
#define LFSR_DATA_DISK(_block, _off, _size) \
((lfsr_data_t){ \
.u.disk.size=LFSR_DATA_ONDISK | (_size), \
.u.disk.block=_block, \
.u.disk.off=_off})
#define LFSR_DATA_BUF(_buffer, _size) \
((lfsr_data_t){ \
.u.buf.size=_size, \
.u.buf.mode=LFSR_DATA_BUF, \
.u.buf.buffer=(const void*)(_buffer)})
#define LFSR_DATA_IMM(_buffer, _size) \
lfsr_data_fromimm(_buffer, _size)
#define LFSR_DATA_LEB128(_word) \
lfsr_data_fromleb128(_word)
// this relies on temporary allocations which is a bit precarious...
#define LFSR_DATA_CAT(...) \
lfsr_data_fromcat( \
(const lfsr_data_t[]){__VA_ARGS__}, \
sizeof((const lfsr_data_t[]){__VA_ARGS__}) / sizeof(lfsr_data_t))
// These aren't true runtime-typed datas, but allows some special cases to
// bypass data encoding. External context is required to access these
// correctly.
// a move of all attrs from an mdir entry
#define LFSR_DATA_MOVE(_mdir) \
((lfsr_data_t){.u.buf.buffer=(const void*)(const lfsr_mdir_t*){_mdir}})
// a grm update, note this is mutable! we may update the grm during
// mdir commits
#define LFSR_DATA_GRM(_grm) \
((lfsr_data_t){.u.buf.buffer=(const void*)(lfsr_grm_t*){_grm}})
// writing to an unrelated trunk in the rbyd
#define LFSR_DATA_SHRUBCOMMIT(_shrub, _rid, _attrs, _attr_count) \
((lfsr_data_t){.u.buf.buffer=(const void*)&(const lfsr_shrubcommit_t){ \
.shrub=_shrub, \
.rid=_rid, \
.attrs=_attrs, \
.attr_count=_attr_count}})
#define LFSR_DATA_SHRUBTRUNK(_shrub) \
((lfsr_data_t){.u.buf.buffer=(const void*)(const lfsr_shrub_t*){_shrub}})
static inline bool lfsr_data_ondisk(const lfsr_data_t *data) {
return data->u.size & LFSR_DATA_ONDISK;
}
static inline bool lfsr_data_isbuf(const lfsr_data_t *data) {
return !lfsr_data_ondisk(data) && data->u.buf.mode == LFSR_DATA_BUF;
}
static inline bool lfsr_data_isimm(const lfsr_data_t *data) {
return !lfsr_data_ondisk(data) && data->u.buf.mode == LFSR_DATA_IMM;
}
static inline bool lfsr_data_iscat(const lfsr_data_t *data) {
return !lfsr_data_ondisk(data) && data->u.buf.mode == LFSR_DATA_CAT;
}
static inline lfs_size_t lfsr_data_size(const lfsr_data_t *data) {
return data->u.size & ~LFSR_DATA_ONDISK;
}
// some data initializers just can't be macros, we at least make these inline
// so most of the internal logic is hopefully elided
static inline lfsr_data_t lfsr_data_fromimm(
const void *buffer, lfs_size_t size) {
LFS_ASSERT(size <= 5);
lfsr_data_t data;
memcpy(data.u.imm.buf, buffer, size);
data.u.imm.size = size;
data.u.imm.mode = LFSR_DATA_IMM;
return data;
}
static inline lfsr_data_t lfsr_data_fromleb128(int32_t word) {
lfsr_data_t data;
lfs_ssize_t size = lfs_toleb128(word, data.u.imm.buf, 5);
LFS_ASSERT(size >= 0);
LFS_ASSERT(size <= 5);
data.u.imm.size = size;
data.u.imm.mode = LFSR_DATA_IMM;
return data;
}
static inline lfsr_data_t lfsr_data_fromcat(
const lfsr_data_t *datas, lfs_size_t count) {
LFS_ASSERT(count <= 255);
// find total size
lfs_size_t size = 0;
for (uint8_t i = 0; i < count; i++) {
size += lfsr_data_size(&datas[i]);
}
return (lfsr_data_t){
.u.cat.size=size,
.u.cat.mode=LFSR_DATA_CAT,
.u.cat.count=count,
.u.cat.datas=datas};
}
// note these operations only work on "simple" (not concatenated) datas
static lfsr_data_t lfsr_data_slice(lfsr_data_t data,
lfs_ssize_t off, lfs_ssize_t size) {
// limit our off/size to data range, note the use of unsigned casts
// here to treat -1 as unbounded
lfs_size_t off_ = lfs_min32(
lfs_smax32(off, 0),
lfsr_data_size(&data));
lfs_size_t size_ = lfs_min32(
(lfs_size_t)size,
lfsr_data_size(&data) - off_);
// on-disk? increment
if (lfsr_data_ondisk(&data)) {
data.u.disk.off += off_;
data.u.disk.size = LFSR_DATA_ONDISK | size_;
// buffer? increment
} else if (lfsr_data_isbuf(&data)) {
data.u.buf.buffer += off_;
data.u.buf.size = size_;
// inlined? internal memmove
} else if (lfsr_data_isimm(&data)) {
memmove(data.u.imm.buf,
data.u.imm.buf + off_,
size_);
data.u.imm.size = size_;
// concatenated? not supported
} else {
LFS_UNREACHABLE();
}
return data;
}
static lfsr_data_t lfsr_data_truncate(lfsr_data_t data, lfs_size_t size) {
return lfsr_data_slice(data, -1, size);
}
static lfsr_data_t lfsr_data_fruncate(lfsr_data_t data, lfs_size_t size) {
return lfsr_data_slice(data,
lfsr_data_size(&data) - lfs_min32(
size,
lfsr_data_size(&data)),
-1);
}
// data <-> bd interactions
// lfsr_data_read* operations update the lfsr_data_t, effectively
// consuming the data
static lfs_ssize_t lfsr_data_read(lfs_t *lfs, lfsr_data_t *data,
void *buffer, lfs_size_t size) {
// limit our size to data range
lfs_size_t d = lfs_min32(size, lfsr_data_size(data));
// on-disk?
if (lfsr_data_ondisk(data)) {
int err = lfsr_bd_read(lfs, data->u.disk.block, data->u.disk.off,
// note our hint includes the full data range
lfsr_data_size(data),
buffer, d);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
// buffer?
} else if (lfsr_data_isbuf(data)) {
memcpy(buffer, data->u.buf.buffer, d);
// inlined?
} else if (lfsr_data_isimm(data)) {
memcpy(buffer, data->u.imm.buf, d);
// concatenated? not supported
} else {
LFS_UNREACHABLE();
}
*data = lfsr_data_slice(*data, d, -1);
return d;
}
static int lfsr_data_readle32(lfs_t *lfs, lfsr_data_t *data,
uint32_t *word) {
uint8_t buf[4];
lfs_ssize_t d = lfsr_data_read(lfs, data, buf, 4);
if (d < 0) {
return d;
}
// truncated?
if (d < 4) {
return LFS_ERR_CORRUPT;
}
*word = lfs_fromle32_(buf);
return 0;
}
static int lfsr_data_readleb128(lfs_t *lfs, lfsr_data_t *data,
int32_t *word_) {
// note we make sure not to update our data offset until after leb128
// decoding
lfsr_data_t data_ = *data;
// for 32-bits we can assume worst-case leb128 size is 5-bytes
uint8_t buf[5];
lfs_ssize_t d = lfsr_data_read(lfs, &data_, buf, 5);
if (d < 0) {
return d;
}
d = lfs_fromleb128(word_, buf, d);
if (d < 0) {
return d;
}
*data = lfsr_data_slice(*data, d, -1);
return 0;
}
static lfs_scmp_t lfsr_data_cmp(lfs_t *lfs, const lfsr_data_t *data,
const void *buffer, lfs_size_t size) {
// limit our size to data range
lfs_size_t d = lfs_min32(size, lfsr_data_size(data));
// on-disk?
if (lfsr_data_ondisk(data)) {
int cmp = lfsr_bd_cmp(lfs, data->u.disk.block, data->u.disk.off, 0,
buffer, d);
if (cmp != LFS_CMP_EQ) {
return cmp;
}
// buffer?
} else if (lfsr_data_isbuf(data)) {
int cmp = memcmp(data->u.buf.buffer, buffer, d);
if (cmp < 0) {
return LFS_CMP_LT;
} else if (cmp > 0) {
return LFS_CMP_GT;
}
// inlined?
} else if (lfsr_data_isimm(data)) {
int cmp = memcmp(data->u.imm.buf, buffer, d);
if (cmp < 0) {
return LFS_CMP_LT;
} else if (cmp > 0) {
return LFS_CMP_GT;
}
// concatenated? not supported
} else {
LFS_UNREACHABLE();
}
// if data is equal, check for size mismatch
if (lfsr_data_size(data) < size) {
return LFS_CMP_LT;
} else if (lfsr_data_size(data) > size) {
return LFS_CMP_GT;
} else {
return LFS_CMP_EQ;
}
}
static lfs_scmp_t lfsr_data_namecmp(lfs_t *lfs, const lfsr_data_t *data,
lfsr_did_t did, const char *name, lfs_size_t name_size) {
// first compare the did
lfsr_data_t data_ = *data;
lfsr_did_t did_;
int err = lfsr_data_readleb128(lfs, &data_, (int32_t*)&did_);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
if (did_ < did) {
return LFS_CMP_LT;
} else if (did_ > did) {
return LFS_CMP_GT;
}
// then compare the actual name
return lfsr_data_cmp(lfs, &data_, name, name_size);
}
static int lfsr_bd_progdata_(lfs_t *lfs,
lfs_block_t block, lfs_size_t off, lfsr_data_t data,
uint32_t *cksum_, uint32_t *flcksum_) {
// on-disk?
if (lfsr_data_ondisk(&data)) {
// TODO byte-level copies have been a pain point, works for prototyping
// but can this be better? configurable? leverage
// rcache/pcache directly?
uint8_t dat;
for (lfs_size_t i = 0; i < lfsr_data_size(&data); i++) {
int err = lfsr_bd_read(lfs,
data.u.disk.block, data.u.disk.off+i,
lfsr_data_size(&data)-i,
&dat, 1);
if (err) {
return err;
}
err = lfsr_bd_prog(lfs, block, off+i, &dat, 1,
cksum_, flcksum_);
if (err) {
return err;
}
}
// buffer?
} else if (lfsr_data_isbuf(&data)) {
int err = lfsr_bd_prog(lfs, block, off,
data.u.buf.buffer, data.u.buf.size,
cksum_, flcksum_);
if (err) {
return err;
}
// inlined?
} else if (lfsr_data_isimm(&data)) {
int err = lfsr_bd_prog(lfs, block, off,
data.u.imm.buf, data.u.imm.size,
cksum_, flcksum_);
if (err) {
return err;
}
// concatenated? nesting would require recursion
} else {
LFS_UNREACHABLE();
}
return 0;
}
static int lfsr_bd_progdata(lfs_t *lfs,
lfs_block_t block, lfs_size_t off, lfsr_data_t data,
uint32_t *cksum_, uint32_t *flcksum_) {
// simple data?
if (!lfsr_data_iscat(&data)) {
int err = lfsr_bd_progdata_(lfs, block, off, data,
cksum_, flcksum_);
if (err) {
return err;
}
// concatenated data? handle specially to avoid recursion
} else {
for (uint8_t i = 0; i < data.u.cat.count; i++) {
int err = lfsr_bd_progdata_(lfs, block, off, data.u.cat.datas[i],
cksum_, flcksum_);
if (err) {
return err;
}
off += lfsr_data_size(&data.u.cat.datas[i]);
}
}
return 0;
}
// operations on attribute lists
//struct lfs_mattr {
// lfs_tag_t tag;
// const void *buffer;
//};
//
//struct lfs_diskoff {
// lfs_block_t block;
// lfs_off_t off;
//};
//
//#define LFS_MKATTRS(...)
// (struct lfs_mattr[]){__VA_ARGS__},
// sizeof((struct lfs_mattr[]){__VA_ARGS__}) / sizeof(struct lfs_mattr)
typedef struct lfsr_attr {
lfsr_tag_t tag;
lfsr_srid_t delta;
lfsr_data_t data;
} lfsr_attr_t;
#define LFSR_ATTR(_type, _delta, _data) \
((const lfsr_attr_t){ \
LFSR_TAG_##_type, \
_delta, \
LFSR_DATA_##_data})
#define LFSR_ATTR_NOOP() LFSR_ATTR(NULL, 0, NULL())
// TODO make this const again eventually
#define LFSR_ATTRS(...) \
(const lfsr_attr_t[]){__VA_ARGS__}, \
sizeof((const lfsr_attr_t[]){__VA_ARGS__}) / sizeof(lfsr_attr_t)
// generalized info returned by traveral functions
typedef struct lfsr_tinfo {
lfsr_tag_t tag;
union {
lfsr_data_t data;
lfsr_mdir_t mdir;
lfsr_rbyd_t rbyd;
lfsr_bptr_t bptr;
} u;
} lfsr_tinfo_t;
//struct lfsr_attr_from {
// const lfsr_rbyd_t *rbyd;
// const struct lfsr_attr *attrs;
// lfs_size_t start;
//};
//
//#define LFSR_ATTR_FROM(_id, _rbyd, _attrs, _start, _stop, _next)
// LFSR_ATTR(FROM, _id,
// (&(const struct lfsr_attr_from){_rbyd, _attrs, _start}),
// (_stop)-(_start), _next)
//
//#define LFS_MKRATTR_(...)
// (&(const struct lfsr_attr){__VA_ARGS__})
//
//#define LFS_MKRATTR(type1, type2, id, buffer, size, next)
// (&(const struct lfsr_attr){
// LFS_MKRTAG(type1, type2, id),
// buffer, size, next})
//
//#define LFS_MKRRMATTR(type1, type2, id, next)
// (&(const struct lfsr_attr){
// LFS_MKRRMTAG(type1, type2, id),
// NULL, 0, next})
//// find state when looking up by name
//typedef struct lfsr_find {
// // what to search for
// const char *name;
// lfs_size_t name_size;
//
// // if found, the tag/id will be placed in found_tag/found_id,
// // otherwise found_tag will be zero and found_id will be set to
// // the largest, smaller id (a good place to insert)
// lfs_ssize_t predicted_id;
// lfs_ssize_t found_id;
// lfsr_tag_t predicted_tag;
// lfsr_tag_t found_tag;
//} lfsr_find_t;
//// operations on global state
//static inline void lfs_gstate_xor(lfs_gstate_t *a, const lfs_gstate_t *b) {
// for (int i = 0; i < 3; i++) {
// ((uint32_t*)a)[i] ^= ((const uint32_t*)b)[i];
// }
//}
//
//static inline bool lfs_gstate_iszero(const lfs_gstate_t *a) {
// for (int i = 0; i < 3; i++) {
// if (((uint32_t*)a)[i] != 0) {
// return false;
// }
// }
// return true;
//}
//
//#ifndef LFS_READONLY
//static inline bool lfs_gstate_hasorphans(const lfs_gstate_t *a) {
// return lfs_tag_size(a->tag);
//}
//
//static inline uint8_t lfs_gstate_getorphans(const lfs_gstate_t *a) {
// return lfs_tag_size(a->tag);
//}
//
//static inline bool lfs_gstate_hasmove(const lfs_gstate_t *a) {
// return lfs_tag_type1(a->tag);
//}
//#endif
//
//static inline bool lfs_gstate_hasmovehere(const lfs_gstate_t *a,
// const lfs_block_t *pair) {
// return lfs_tag_type1(a->tag) && lfs_pair_cmp(a->pair, pair) == 0;
//}
//
//static inline void lfs_gstate_fromle32(lfs_gstate_t *a) {
// a->tag = lfs_fromle32(a->tag);
// a->pair[0] = lfs_fromle32(a->pair[0]);
// a->pair[1] = lfs_fromle32(a->pair[1]);
//}
//
//#ifndef LFS_READONLY
//static inline void lfs_gstate_tole32(lfs_gstate_t *a) {
// a->tag = lfs_tole32(a->tag);
// a->pair[0] = lfs_tole32(a->pair[0]);
// a->pair[1] = lfs_tole32(a->pair[1]);
//}
//#endif
//
//// operations on forward-CRCs used to track erased state
//struct lfs_fcrc {
// lfs_size_t size;
// uint32_t crc;
//};
//
//static void lfs_fcrc_fromle32(struct lfs_fcrc *fcrc) {
// fcrc->size = lfs_fromle32(fcrc->size);
// fcrc->crc = lfs_fromle32(fcrc->crc);
//}
//
//#ifndef LFS_READONLY
//static void lfs_fcrc_tole32(struct lfs_fcrc *fcrc) {
// fcrc->size = lfs_tole32(fcrc->size);
// fcrc->crc = lfs_tole32(fcrc->crc);
//}
//#endif
// erased-state checksum stuff
static int lfsr_ecksum_validate(lfs_t *lfs, const lfsr_ecksum_t *ecksum,
lfs_block_t block, lfs_size_t off) {
LFS_ASSERT(ecksum->size != -1);
LFS_ASSERT(off < lfs->cfg->block_size);
// check that erased-state matches our checksum, if this fails
// most likely a write was interrupted
uint32_t cksum_ = 0;
int err = lfsr_bd_cksum(lfs, block, off, 0, ecksum->size,
&cksum_);
if (err) {
return err;
}
// ecksum mismatch?
if (cksum_ != ecksum->cksum) {
return LFS_ERR_CORRUPT;
}
return 0;
}
// erased-state checksum on-disk encoding
// 1 leb128 + 1 crc32c => 9 bytes (worst case)
#define LFSR_ECKSUM_DSIZE (5+4)
#define LFSR_DATA_FROMECKSUM(_ecksum, _buffer) \
lfsr_data_fromecksum(_ecksum, _buffer)
static lfsr_data_t lfsr_data_fromecksum(const lfsr_ecksum_t *ecksum,
uint8_t buffer[static LFSR_ECKSUM_DSIZE]) {
LFS_ASSERT(ecksum->size != -1);
lfs_ssize_t d = 0;
lfs_ssize_t d_ = lfs_toleb128(ecksum->size, &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
lfs_tole32_(ecksum->cksum, &buffer[d]);
d += 4;
return LFSR_DATA_BUF(buffer, d);
}
static int lfsr_data_readecksum(lfs_t *lfs, lfsr_data_t *data,
lfsr_ecksum_t *ecksum) {
int err = lfsr_data_readleb128(lfs, data, (int32_t*)&ecksum->size);
if (err) {
return err;
}
err = lfsr_data_readle32(lfs, data, &ecksum->cksum);
if (err) {
return err;
}
return 0;
}
// block pointer things
// 4 leb128s + 1 crc32c => 24 bytes (worst case)
#define LFSR_BPTR_DSIZE (5+5+5+5+4)
#define LFSR_DATA_FROMBPTR(_bptr, _buffer) \
lfsr_data_frombptr(_bptr, _buffer)
static lfsr_data_t lfsr_data_frombptr(const lfsr_bptr_t *bptr,
uint8_t buffer[static LFSR_BPTR_DSIZE]) {
lfs_ssize_t d = 0;
// write the block, offset, size
lfs_ssize_t d_ = lfs_toleb128(lfsr_data_size(&bptr->data), &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
d_ = lfs_toleb128(bptr->data.u.disk.block, &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
d_ = lfs_toleb128(bptr->data.u.disk.off, &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
// write the cksize, cksum
d_ = lfs_toleb128(bptr->cksize, &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
lfs_tole32_(bptr->cksum, &buffer[d]);
d += 4;
return LFSR_DATA_BUF(buffer, d);
}
static int lfsr_data_readbptr(lfs_t *lfs, lfsr_data_t *data,
lfsr_bptr_t *bptr) {
// read the block, offset, size
int err = lfsr_data_readleb128(lfs, data,
(int32_t*)&bptr->data.u.disk.size);
if (err) {
return err;
}
err = lfsr_data_readleb128(lfs, data, (int32_t*)&bptr->data.u.disk.block);
if (err) {
return err;
}
err = lfsr_data_readleb128(lfs, data, (int32_t*)&bptr->data.u.disk.off);
if (err) {
return err;
}
// read the cksize, cksum
err = lfsr_data_readleb128(lfs, data, (int32_t*)&bptr->cksize);
if (err) {
return err;
}
err = lfsr_data_readle32(lfs, data, &bptr->cksum);
if (err) {
return err;
}
// all bptrs have this flag set, this is used to differentiate
// bptrs from btrees in files
bptr->data.u.disk.size |= LFSR_DATA_ONDISK;
return 0;
}
//// other endianness operations
//static void lfs_ctz_fromle32(struct lfs_ctz *ctz) {
// ctz->head = lfs_fromle32(ctz->head);
// ctz->size = lfs_fromle32(ctz->size);
//}
//
//#ifndef LFS_READONLY
//static void lfs_ctz_tole32(struct lfs_ctz *ctz) {
// ctz->head = lfs_tole32(ctz->head);
// ctz->size = lfs_tole32(ctz->size);
//}
//#endif
//
//static inline void lfs_superblock_fromle32(lfs_superblock_t *superblock) {
// superblock->version = lfs_fromle32(superblock->version);
// superblock->block_size = lfs_fromle32(superblock->block_size);
// superblock->block_count = lfs_fromle32(superblock->block_count);
// superblock->name_max = lfs_fromle32(superblock->name_max);
// superblock->file_max = lfs_fromle32(superblock->file_max);
// superblock->attr_max = lfs_fromle32(superblock->attr_max);
//}
//
//#ifndef LFS_READONLY
//static inline void lfs_superblock_tole32(lfs_superblock_t *superblock) {
// superblock->version = lfs_tole32(superblock->version);
// superblock->block_size = lfs_tole32(superblock->block_size);
// superblock->block_count = lfs_tole32(superblock->block_count);
// superblock->name_max = lfs_tole32(superblock->name_max);
// superblock->file_max = lfs_tole32(superblock->file_max);
// superblock->attr_max = lfs_tole32(superblock->attr_max);
//}
//#endif
//
//#ifndef LFS_NO_ASSERT
//static bool lfs_mlist_isopen(struct lfs_mlist *head,
// struct lfs_mlist *node) {
// for (struct lfs_mlist **p = &head; *p; p = &(*p)->next) {
// if (*p == (struct lfs_mlist*)node) {
// return true;
// }
// }
//
// return false;
//}
//#endif
//
//static void lfs_mlist_remove(lfs_t *lfs, struct lfs_mlist *mlist) {
// for (struct lfs_mlist **p = &lfs->mlist; *p; p = &(*p)->next) {
// if (*p == mlist) {
// *p = (*p)->next;
// break;
// }
// }
//}
//
//static void lfs_mlist_append(lfs_t *lfs, struct lfs_mlist *mlist) {
// mlist->next = lfs->mlist;
// lfs->mlist = mlist;
//}
/// Global-state things ///
static inline bool lfsr_gdelta_iszero(
const uint8_t *gdelta, lfs_size_t size) {
// this condition is probably optimized out by constant propagation
if (size == 0) {
return true;
}
// check that gdelta is all zeros
return gdelta[0] == 0 && memcmp(&gdelta[0], &gdelta[1], size-1) == 0;
}
static inline lfs_size_t lfsr_gdelta_size(
const uint8_t *gdelta, lfs_size_t size) {
// truncate based on number of trailing zeros
while (size > 0 && gdelta[size-1] == 0) {
size -= 1;
}
return size;
}
static int lfsr_gdelta_xor(lfs_t *lfs,
uint8_t *gdelta, lfs_size_t size,
lfsr_data_t xor) {
// check for overflow
lfs_size_t xor_size = lfsr_data_size(&xor);
LFS_ASSERT(xor_size <= size);
if (xor_size > size) {
return LFS_ERR_CORRUPT;
}
// TODO is there a way to avoid byte-level operations here?
// xor with data, this should at least be cached if on-disk
for (lfs_size_t i = 0; i < xor_size; i++) {
uint8_t x;
lfs_ssize_t d = lfsr_data_read(lfs, &xor, &x, 1);
if (d < 0) {
return d;
}
gdelta[i] ^= x;
}
return 0;
}
// grm (global remove) things
static inline bool lfsr_grm_hasrm(const lfsr_grm_t *grm) {
return grm->rms[0] != -1;
}
static inline uint8_t lfsr_grm_count(const lfsr_grm_t *grm) {
return (grm->rms[0] != -1) + (grm->rms[1] != -1);
}
static inline void lfsr_grm_pushrm(lfsr_grm_t *grm, lfsr_smid_t mid) {
LFS_ASSERT(grm->rms[1] == -1);
grm->rms[1] = grm->rms[0];
grm->rms[0] = mid;
}
static inline void lfsr_grm_poprm(lfsr_grm_t *grm) {
grm->rms[0] = grm->rms[1];
grm->rms[1] = -1;
}
static inline bool lfsr_grm_isrm(const lfsr_grm_t *grm, lfsr_smid_t mid) {
return grm->rms[0] == mid || grm->rms[1] == mid;
}
static inline bool lfsr_grm_iszero(
const uint8_t gdelta[static LFSR_GRM_DSIZE]) {
return lfsr_gdelta_iszero(gdelta, LFSR_GRM_DSIZE);
}
static inline lfs_size_t lfsr_grm_size(
const uint8_t gdelta[static LFSR_GRM_DSIZE]) {
return lfsr_gdelta_size(gdelta, LFSR_GRM_DSIZE);
}
static inline int lfsr_grm_xor(lfs_t *lfs,
uint8_t gdelta[static LFSR_GRM_DSIZE],
lfsr_data_t xor) {
return lfsr_gdelta_xor(lfs, gdelta, LFSR_GRM_DSIZE, xor);
}
#define LFSR_DATA_FROMGRM(_grm, _buffer) \
lfsr_data_fromgrm(_grm, _buffer)
static lfsr_data_t lfsr_data_fromgrm(const lfsr_grm_t *grm,
uint8_t buffer[static LFSR_GRM_DSIZE]) {
// make sure to zero so we don't leak any info
memset(buffer, 0, LFSR_GRM_DSIZE);
// first encode the number of grms, this can be 0, 1, or 2 and may
// be extended to a general purpose leb128 type field in the future
uint8_t mode = lfsr_grm_count(grm);
lfs_ssize_t d = 0;
buffer[d] = mode;
d += 1;
for (uint8_t i = 0; i < mode; i++) {
lfs_ssize_t d_ = lfs_toleb128(grm->rms[i], &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
}
return LFSR_DATA_BUF(buffer, lfsr_grm_size(buffer));
}
// required by lfsr_data_readgrm
static inline lfsr_mid_t lfsr_mweight(lfs_t *lfs);
static inline lfsr_mid_t lfsr_mtree_weight(lfs_t *lfs);
static int lfsr_data_readgrm(lfs_t *lfs, lfsr_data_t *data,
lfsr_grm_t *grm) {
// clear first
grm->rms[0] = -1;
grm->rms[1] = -1;
// first read the mode field
lfs_size_t mode;
int err = lfsr_data_readleb128(lfs, data, (int32_t*)&mode);
if (err) {
return err;
}
// unknown mode? return an error, we may be able to mount read-only
if (mode > 2) {
return LFS_ERR_INVAL;
}
for (uint8_t i = 0; i < mode; i++) {
err = lfsr_data_readleb128(lfs, data, &grm->rms[i]);
if (err) {
return err;
}
LFS_ASSERT(grm->rms[i] < lfs_smax32(
lfsr_mtree_weight(lfs),
lfsr_mweight(lfs)));
}
return 0;
}
/// Internal operations predeclared here ///
//#ifndef LFS_READONLY
//static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
// const struct lfs_mattr *attrs, int attrcount);
//static int lfs_dir_compact(lfs_t *lfs,
// lfs_mdir_t *dir, const struct lfs_mattr *attrs, int attrcount,
// lfs_mdir_t *source, uint16_t begin, uint16_t end);
//static lfs_ssize_t lfs_file_flushedwrite(lfs_t *lfs, lfs_file_t *file,
// const void *buffer, lfs_size_t size);
//static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
// const void *buffer, lfs_size_t size);
//static int lfs_file_rawsync(lfs_t *lfs, lfs_file_t *file);
//static int lfs_file_outline(lfs_t *lfs, lfs_file_t *file);
//static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file);
//
//static int lfs_fs_deorphan(lfs_t *lfs, bool powerloss);
//static int lfs_fs_preporphans(lfs_t *lfs, int8_t orphans);
//static void lfs_fs_prepmove(lfs_t *lfs,
// uint16_t id, const lfs_block_t pair[2]);
//static int lfs_fs_pred(lfs_t *lfs, const lfs_block_t dir[2],
// lfs_mdir_t *pdir);
//static lfs_stag_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t dir[2],
// lfs_mdir_t *parent);
//static int lfs_fs_forceconsistency(lfs_t *lfs);
//#endif
//
//#ifdef LFS_MIGRATE
//static int lfs1_traverse(lfs_t *lfs,
// int (*cb)(void*, lfs_block_t), void *data);
//#endif
//
//static int lfs_dir_rawrewind(lfs_t *lfs, lfs_dir_t *dir);
//
//static lfs_ssize_t lfs_file_flushedread(lfs_t *lfs, lfs_file_t *file,
// void *buffer, lfs_size_t size);
//static lfs_ssize_t lfs_file_rawread(lfs_t *lfs, lfs_file_t *file,
// void *buffer, lfs_size_t size);
//static int lfs_file_rawclose(lfs_t *lfs, lfs_file_t *file);
//static lfs_soff_t lfs_file_rawsize(lfs_t *lfs, lfs_file_t *file);
//
//static lfs_ssize_t lfs_fs_rawsize(lfs_t *lfs);
//static int lfs_fs_rawtraverse(lfs_t *lfs,
// int (*cb)(void *data, lfs_block_t block), void *data,
// bool includeorphans);
//static int lfs_deinit(lfs_t *lfs);
//static int lfs_rawunmount(lfs_t *lfs);
// predeclare block allocator functions
static int lfs_alloc(lfs_t *lfs, lfs_block_t *block);
static void lfs_alloc_ckpoint(lfs_t *lfs);
/// Red-black-yellow Dhara tree operations ///
#define LFSR_RBYD_SHRUB 0x80000000
// helper functions
static inline bool lfsr_rbyd_isshrub(const lfsr_rbyd_t *rbyd) {
return rbyd->trunk & LFSR_RBYD_SHRUB;
}
static inline lfs_size_t lfsr_rbyd_trunk(const lfsr_rbyd_t *rbyd) {
return rbyd->trunk & ~LFSR_RBYD_SHRUB;
}
static inline bool lfsr_rbyd_hastrunk(const lfsr_rbyd_t *rbyd) {
return lfsr_rbyd_trunk(rbyd) != 0;
}
static inline bool lfsr_rbyd_isfetched(const lfsr_rbyd_t *rbyd) {
return !(lfsr_rbyd_hastrunk(rbyd) && rbyd->eoff == 0);
}
static inline int lfsr_rbyd_cmp(
const lfsr_rbyd_t *a,
const lfsr_rbyd_t *b) {
if (a->blocks[0] != b->blocks[0]) {
return a->blocks[0] - b->blocks[0];
} else {
return a->trunk - b->trunk;
}
}
// allocate an rbyd block
static int lfsr_rbyd_alloc(lfs_t *lfs, lfsr_rbyd_t *rbyd) {
*rbyd = (lfsr_rbyd_t){.weight=0, .trunk=0, .eoff=0, .cksum=0};
int err = lfs_alloc(lfs, &rbyd->blocks[0]);
if (err) {
return err;
}
// TODO should erase be implicit in alloc eventually?
err = lfsr_bd_erase(lfs, rbyd->blocks[0]);
if (err) {
return err;
}
return 0;
}
static int lfsr_rbyd_fetch(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_block_t block, lfs_ssize_t trunk) {
// checksum the revision count to get the cksum started
uint32_t cksum = 0;
int err = lfsr_bd_cksum(lfs, block, 0, lfs->cfg->block_size,
sizeof(uint32_t), &cksum);
if (err) {
return err;
}
rbyd->blocks[0] = block;
rbyd->eoff = 0;
rbyd->trunk = (trunk & LFSR_RBYD_SHRUB) | 0;
trunk &= ~LFSR_RBYD_SHRUB;
// temporary state until we validate a cksum
lfs_size_t off = sizeof(uint32_t);
lfs_size_t trunk_ = 0;
lfs_size_t trunk__ = 0;
bool wastrunk = false;
lfsr_rid_t weight = 0;
lfsr_rid_t weight_ = 0;
// assume unerased until proven otherwise
lfsr_ecksum_t ecksum = {.size=-1};
// scan tags, checking valid bits, cksums, etc
while (off < lfs->cfg->block_size
&& (!trunk || rbyd->eoff <= (lfs_size_t)trunk)) {
lfsr_tag_t tag;
lfsr_rid_t weight__;
lfs_size_t size;
lfs_ssize_t d = lfsr_bd_readtag(lfs,
block, off, lfs->cfg->block_size,
&tag, &weight__, &size, &cksum);
if (d < 0) {
if (d == LFS_ERR_INVAL || d == LFS_ERR_CORRUPT) {
// if we are breaking for any reason other than the tag's
// valid bit, our ecksum must be invalid
if (d != LFS_ERR_INVAL) {
ecksum.size = -1;
}
break;
}
return d;
}
lfs_size_t off_ = off + d;
// tag goes out of range?
if (!lfsr_tag_isalt(tag) && off_ + size > lfs->cfg->block_size) {
break;
}
// not an end-of-commit cksum
if (!lfsr_tag_isalt(tag) && lfsr_tag_suptype(tag) != LFSR_TAG_CKSUM) {
// cksum the entry, hopefully leaving it in the cache
err = lfsr_bd_cksum(lfs, block, off_, lfs->cfg->block_size, size,
&cksum);
if (err) {
if (err == LFS_ERR_CORRUPT) {
break;
}
return err;
}
// found an ecksum? save for later
if (tag == LFSR_TAG_ECKSUM) {
err = lfsr_data_readecksum(lfs,
&LFSR_DATA_DISK(block, off_,
lfs->cfg->block_size - off_),
&ecksum);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// TODO ignore?? why not break?
// ignore malformed ecksums
if (err == LFS_ERR_CORRUPT) {
ecksum.size = -1;
}
}
// is an end-of-commit cksum
} else if (!lfsr_tag_isalt(tag)) {
uint32_t cksum_ = 0;
err = lfsr_bd_read(lfs, block, off_, lfs->cfg->block_size,
&cksum_, sizeof(uint32_t));
if (err) {
if (err == LFS_ERR_CORRUPT) {
break;
}
return err;
}
cksum_ = lfs_fromle32_(&cksum_);
if (cksum != cksum_) {
// uh oh, cksums don't match
break;
}
// toss our cksum into the filesystem seed for
// pseudorandom numbers, note we use another cksum here
// as a collection function because it is sufficiently
// random and convenient
lfs->seed = lfs_crc32c(lfs->seed, &cksum, sizeof(uint32_t));
// save what we've found so far
rbyd->eoff = off_ + size;
rbyd->cksum = cksum;
rbyd->trunk = (LFSR_RBYD_SHRUB & rbyd->trunk) | trunk_;
rbyd->weight = weight;
}
// found a trunk of a tree?
if (lfsr_tag_istrunk(tag)
&& (!trunk || (lfs_size_t)trunk >= off || wastrunk)) {
// start of trunk?
if (!wastrunk) {
wastrunk = true;
// keep track of trunk's entry point
trunk__ = off;
// reset weight
weight_ = 0;
}
// derive weight of the tree from alt pointers
//
// NOTE we can't check for overflow/underflow here because we
// may be overeagerly parsing an invalid commit, it's ok for
// this to overflow/underflow as long as we throw it out later
// on a bad cksum
weight_ += weight__;
// end of trunk?
if (!lfsr_tag_isalt(tag)) {
wastrunk = false;
// update most recent trunk and weight, unless we are a
// shrub trunk
if (!lfsr_tag_isshrub(tag)) {
trunk_ = trunk__;
weight = weight_;
}
}
}
// skip data
if (!lfsr_tag_isalt(tag)) {
off_ += size;
}
off = off_;
}
// no valid commits?
if (!lfsr_rbyd_hastrunk(rbyd)) {
return LFS_ERR_CORRUPT;
}
// did we end on a valid commit? we may have an erased state
bool erased = false;
if (rbyd->eoff < lfs->cfg->block_size
&& rbyd->eoff % lfs->cfg->prog_size == 0
&& ecksum.size != -1) {
err = lfsr_ecksum_validate(lfs, &ecksum, rbyd->blocks[0], rbyd->eoff);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
erased = (err != LFS_ERR_CORRUPT);
}
if (!erased) {
rbyd->eoff = -1;
}
return 0;
}
// a more aggressive fetch when checksum is known
static int lfsr_rbyd_fetchvalidate(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_block_t block, lfs_ssize_t trunk, lfsr_rid_t weight,
uint32_t cksum) {
int err = lfsr_rbyd_fetch(lfs, rbyd, block, trunk);
if (err) {
if (err == LFS_ERR_CORRUPT) {
LFS_ERROR("Found corrupted rbyd 0x%"PRIx32".%"PRIx32", "
"cksum 0x%08"PRIx32,
block, trunk, cksum);
}
return err;
}
// test that our cksum matches what's expected
//
// it should be noted that this is very unlikely to happen without the
// above fetch failing, since that would require the rbyd to have the
// same trunk and pass its internal cksum
if (rbyd->cksum != cksum) {
LFS_ERROR("Found rbyd cksum mismatch rbyd 0x%"PRIx32".%"PRIx32", "
"cksum 0x%08"PRIx32" (!= 0x%08"PRIx32")",
rbyd->blocks[0], lfsr_rbyd_trunk(rbyd), rbyd->cksum, cksum);
return LFS_ERR_CORRUPT;
}
// if trunk/weight mismatch _after_ cksums match, that's not a storage
// error, that's a programming error
LFS_ASSERT(lfsr_rbyd_trunk(rbyd) == (lfs_size_t)trunk);
LFS_ASSERT((lfsr_rid_t)rbyd->weight == weight);
return 0;
}
static int lfsr_rbyd_lookupnext(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfsr_srid_t rid, lfsr_tag_t tag,
lfsr_srid_t *rid_, lfsr_tag_t *tag_, lfsr_rid_t *weight_,
lfsr_data_t *data_) {
// these bits should be clear at this point
LFS_ASSERT(lfsr_tag_mode(tag) == 0);
// make sure we never look up zero tags, the way we create
// unreachable tags has a hole here
tag = lfs_max16(tag, 0x1);
// out of bounds? no trunk yet?
if (rid >= rbyd->weight || !lfsr_rbyd_hastrunk(rbyd)) {
return LFS_ERR_NOENT;
}
// keep track of bounds as we descend down the tree
lfs_size_t branch = lfsr_rbyd_trunk(rbyd);
lfsr_srid_t lower = 0;
lfsr_srid_t upper = rbyd->weight;
// descend down tree
while (true) {
lfsr_tag_t alt;
lfsr_rid_t weight;
lfs_size_t jump;
lfs_ssize_t d = lfsr_bd_readtag(lfs,
rbyd->blocks[0], branch, 0,
&alt, &weight, &jump, NULL);
if (d < 0) {
return d;
}
// found an alt?
if (lfsr_tag_isalt(alt)) {
if (lfsr_tag_follow(alt, weight, lower, upper, rid, tag)) {
lfsr_tag_flip(&alt, &weight, lower, upper);
lfsr_tag_trim(alt, weight, &lower, &upper, NULL, NULL);
branch = branch - jump;
} else {
lfsr_tag_trim(alt, weight, &lower, &upper, NULL, NULL);
branch = branch + d;
}
// found end of tree?
} else {
// update the tag rid
lfsr_srid_t rid__ = upper-1;
lfsr_tag_t tag__ = lfsr_tag_key(alt);
// not what we're looking for?
if (!tag__
|| rid__ < rid
|| (rid__ == rid && tag__ < tag)) {
return LFS_ERR_NOENT;
}
// save what we found
// TODO how many of these need to be conditional?
if (rid_) {
*rid_ = rid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = upper - lower;
}
if (data_) {
*data_ = LFSR_DATA_DISK(rbyd->blocks[0], branch + d, jump);
}
return 0;
}
}
}
static int lfsr_rbyd_lookup(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfsr_srid_t rid, lfsr_tag_t tag,
lfsr_data_t *data_) {
lfsr_srid_t rid_;
lfsr_tag_t tag_;
int err = lfsr_rbyd_lookupnext(lfs, rbyd, rid, tag,
&rid_, &tag_, NULL, data_);
if (err) {
return err;
}
// lookup finds the next-smallest tag, all we need to do is fail if it
// picks up the wrong tag
if (rid_ != rid || tag_ != tag) {
return LFS_ERR_NOENT;
}
return 0;
}
static int lfsr_rbyd_sublookup(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfsr_srid_t rid, lfsr_tag_t tag,
lfsr_tag_t *tag_, lfsr_data_t *data_) {
// looking up a wide tag with subtype is probably a mistake
LFS_ASSERT(lfsr_tag_subtype(tag) == 0);
lfsr_srid_t rid_;
lfsr_tag_t tag__;
int err = lfsr_rbyd_lookupnext(lfs, rbyd, rid, tag,
&rid_, &tag__, NULL, data_);
if (err) {
return err;
}
// the difference between lookup and sublookup is we accept any
// subtype of the requested tag
if (rid_ != rid || lfsr_tag_suptype(tag__) != tag) {
return LFS_ERR_NOENT;
}
if (tag_) {
*tag_ = tag__;
}
return 0;
}
static int lfsr_rbyd_suplookup(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfsr_srid_t rid,
lfsr_tag_t *tag_, lfsr_data_t *data_) {
lfsr_srid_t rid_;
lfsr_tag_t tag__;
int err = lfsr_rbyd_lookupnext(lfs, rbyd, rid, 0,
&rid_, &tag__, NULL, data_);
if (err) {
return err;
}
// the difference between lookup and suplookup is we accept any tag
if (rid_ != rid) {
return LFS_ERR_NOENT;
}
if (tag_) {
*tag_ = tag__;
}
return 0;
}
// append a revision count
//
// this is optional, if not called revision count defaults to 0 (for btrees)
static int lfsr_rbyd_appendrev(lfs_t *lfs, lfsr_rbyd_t *rbyd, uint32_t rev) {
// should only be called before any tags are written
LFS_ASSERT(rbyd->eoff == 0);
// revision count stored as le32, we don't use a leb128 encoding as we
// intentionally allow the revision count to overflow
uint8_t rev_buf[sizeof(uint32_t)];
lfs_tole32_(rev, &rev_buf);
int err = lfsr_bd_prog(lfs, rbyd->blocks[0], rbyd->eoff,
&rev_buf, sizeof(uint32_t),
&rbyd->cksum, NULL);
if (err) {
return err;
}
rbyd->eoff += sizeof(uint32_t);
return 0;
}
// helper functions for managing the 3-element fifo used in
// lfsr_rbyd_appendattr
static int lfsr_rbyd_p_flush(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfsr_tag_t p_alts[static 3],
lfsr_rid_t p_weights[static 3],
lfs_size_t p_jumps[static 3],
int count) {
// write out some number of alt pointers in our queue
for (int i = 0; i < count; i++) {
if (p_alts[3-1-i]) {
// change to a relative jump at the last minute
lfsr_tag_t alt = p_alts[3-1-i];
lfsr_rid_t weight = p_weights[3-1-i];
lfs_size_t jump = rbyd->eoff - p_jumps[3-1-i];
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->blocks[0], rbyd->eoff,
alt, weight, jump,
&rbyd->cksum);
if (d < 0) {
return d;
}
rbyd->eoff += d;
}
}
return 0;
}
static inline int lfsr_rbyd_p_push(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfsr_tag_t p_alts[static 3],
lfsr_rid_t p_weights[static 3],
lfs_size_t p_jumps[static 3],
lfsr_tag_t alt, lfsr_srid_t weight, lfs_size_t jump) {
int err = lfsr_rbyd_p_flush(lfs, rbyd, p_alts, p_weights, p_jumps, 1);
if (err) {
return err;
}
memmove(p_alts+1, p_alts, 2*sizeof(lfsr_tag_t));
memmove(p_weights+1, p_weights, 2*sizeof(lfsr_rid_t));
memmove(p_jumps+1, p_jumps, 2*sizeof(lfs_size_t));
p_alts[0] = alt;
p_weights[0] = weight;
p_jumps[0] = jump;
return 0;
}
static inline void lfsr_rbyd_p_pop(
lfsr_tag_t p_alts[static 3],
lfsr_rid_t p_weights[static 3],
lfs_size_t p_jumps[static 3]) {
memmove(p_alts, p_alts+1, 2*sizeof(lfsr_tag_t));
memmove(p_weights, p_weights+1, 2*sizeof(lfsr_rid_t));
memmove(p_jumps, p_jumps+1, 2*sizeof(lfs_size_t));
p_alts[2] = 0;
p_weights[2] = 0;
p_jumps[2] = 0;
}
static void lfsr_rbyd_p_red(
lfsr_tag_t p_alts[static 3],
lfsr_rid_t p_weights[static 3],
lfs_size_t p_jumps[static 3]) {
// propagate a red edge upwards
p_alts[0] &= ~LFSR_TAG_R;
if (p_alts[1]) {
p_alts[1] |= LFSR_TAG_R;
// reorder so that top two edges always go in the same direction
if (lfsr_tag_isred(p_alts[2])) {
if (lfsr_tag_isparallel(p_alts[1], p_alts[2])) {
// no reorder needed
} else if (lfsr_tag_isparallel(p_alts[0], p_alts[2])) {
lfsr_tag_t alt_ = p_alts[1];
lfsr_rid_t weight_ = p_weights[1];
lfs_size_t jump_ = p_jumps[1];
p_alts[1] = p_alts[0] | LFSR_TAG_R;
p_weights[1] = p_weights[0];
p_jumps[1] = p_jumps[0];
p_alts[0] = alt_ & ~LFSR_TAG_R;
p_weights[0] = weight_;
p_jumps[0] = jump_;
} else if (lfsr_tag_isparallel(p_alts[0], p_alts[1])) {
lfsr_tag_t alt_ = p_alts[2];
lfsr_rid_t weight_ = p_weights[2];
lfs_size_t jump_ = p_jumps[2];
p_alts[2] = p_alts[1] | LFSR_TAG_R;
p_weights[2] = p_weights[1];
p_jumps[2] = p_jumps[1];
p_alts[1] = p_alts[0] | LFSR_TAG_R;
p_weights[1] = p_weights[0];
p_jumps[1] = p_jumps[0];
p_alts[0] = alt_ & ~LFSR_TAG_R;
p_weights[0] = weight_;
p_jumps[0] = jump_;
} else {
LFS_UNREACHABLE();
}
}
}
}
// core rbyd algorithm
static int lfsr_rbyd_appendattr(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfsr_srid_t rid, lfsr_tag_t tag, lfsr_srid_t delta, lfsr_data_t data) {
// must fetch before mutating!
LFS_ASSERT(lfsr_rbyd_isfetched(rbyd));
// tag must not be internal at this point
LFS_ASSERT(!lfsr_tag_isinternal(tag));
// bit 7 is reserved for future subtype extensions
LFS_ASSERT(!(tag & 0x80));
// we can't do anything if we're not erased
if (rbyd->eoff >= lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
// ignore noops
if (!tag) {
LFS_ASSERT(delta == 0);
return 0;
}
// make sure every rbyd starts with a revision count
if (rbyd->eoff == 0) {
int err = lfsr_rbyd_appendrev(lfs, rbyd, 0);
if (err) {
return err;
}
}
// figure out the range of tags we're operating on
//
// several lower bits are reserved, so we repurpose these
// to keep track of some append state
lfsr_srid_t rid_;
lfsr_srid_t other_rid_;
lfsr_tag_t tag_;
lfsr_tag_t other_tag_;
if (delta != 0 && !lfsr_tag_isgrow(tag)) {
if (delta > 0) {
LFS_ASSERT(rid <= rbyd->weight);
rid_ = rid + 1;
other_rid_ = rid + 1;
} else {
LFS_ASSERT(rid < rbyd->weight);
// it's a bit ugly, but adjusting the rid here makes the following
// logic work out more consistently
rid += 1;
rid_ = rid - lfs_smax32(-delta, 0);
other_rid_ = rid;
}
tag_ = 0;
other_tag_ = tag_;
} else {
LFS_ASSERT(rid < rbyd->weight);
rid_ = rid - lfs_smax32(-delta, 0);
other_rid_ = rid;
// note both normal and rm wide-tags have the same bounds, really it's
// the normal non-wide-tags that are an outlier here
if (lfsr_tag_issupwide(tag)) {
tag_ = 0;
other_tag_ = tag_ + 0x800;
} else if (lfsr_tag_issubwide(tag)) {
tag_ = lfsr_tag_supkey(tag);
other_tag_ = tag_ + 0x100;
} else if (lfsr_tag_isrm(tag) || !lfsr_tag_key(tag)) {
tag_ = lfsr_tag_key(tag);
other_tag_ = tag_ + 0x1;
} else {
tag_ = lfsr_tag_key(tag);
other_tag_ = tag_;
}
}
// mark as rmed until found
tag_ |= LFSR_TAG_RM;
other_tag_ |= LFSR_TAG_RM;
// keep track of bounds as we descend down the tree
//
// this gets a bit confusing as we also may need to keep
// track of both the lower and upper bounds of diverging paths
// in the case of range deletions
lfs_size_t branch = lfsr_rbyd_trunk(rbyd);
lfsr_srid_t lower_rid = 0;
lfsr_srid_t upper_rid = rbyd->weight;
lfsr_tag_t lower_tag = 0;
lfsr_tag_t upper_tag = 0xffff;
// diverged state in case we are removing a range from the tree
//
// this is a second copy of the search path state, used to keep track
// of two search paths simulaneously when our range diverges.
//
// note we can't just perform two searches sequentially, or else our tree
// will end up very unbalanced.
lfs_size_t other_branch = 0;
lfsr_srid_t other_lower_rid = 0;
lfsr_srid_t other_upper_rid = 0;
lfsr_tag_t other_lower_tag = 0;
lfsr_tag_t other_upper_tag = 0;
// go ahead and update the rbyd's weight, if an error occurs our
// rbyd is no longer usable anyways
LFS_ASSERT(delta >= -rbyd->weight);
rbyd->weight += delta;
// assume we'll update our trunk
rbyd->trunk = (rbyd->trunk & LFSR_RBYD_SHRUB) | rbyd->eoff;
// no trunk yet?
if (!branch) {
goto leaf;
}
// queue of pending alts we can emulate rotations with
lfsr_tag_t p_alts[3] = {0, 0, 0};
lfsr_rid_t p_weights[3] = {0, 0, 0};
lfs_size_t p_jumps[3] = {0, 0, 0};
lfs_size_t graft = 0;
// descend down tree, building alt pointers
while (true) {
// read the alt pointer
lfsr_tag_t alt;
lfsr_rid_t weight;
lfs_size_t jump;
lfs_ssize_t d = lfsr_bd_readtag(lfs,
rbyd->blocks[0], branch, 0,
&alt, &weight, &jump, NULL);
if (d < 0) {
return d;
}
// found an alt?
if (lfsr_tag_isalt(alt)) {
// make jump absolute
jump = branch - jump;
lfs_size_t branch_ = branch + d;
// do bounds want to take different paths? begin cutting
if (!lfsr_tag_hasdiverged(tag_)
&& lfsr_tag_follow2(alt, weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid,
rid_, tag_)
!= lfsr_tag_follow2(alt, weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid,
other_rid_, other_tag_)) {
// first take care of any lingering red alts
if (lfsr_tag_isred(p_alts[0])) {
alt = p_alts[0] & ~LFSR_TAG_R;
weight = p_weights[0];
jump = p_jumps[0];
branch_ = branch;
lfsr_rbyd_p_pop(p_alts, p_weights, p_jumps);
} else {
tag_ |= LFSR_TAG_DIVERGED | LFSR_TAG_DIVERGEDLOWER;
other_tag_ |= LFSR_TAG_DIVERGED | LFSR_TAG_DIVERGEDUPPER;
other_branch = branch;
other_lower_rid = lower_rid;
other_upper_rid = upper_rid;
other_lower_tag = lower_tag;
other_upper_tag = upper_tag;
}
}
// if we're diverging, go ahead and make alt black, this isn't
// perfect but it's simpler and compact will take care of any
// balance issues that may occur
if (lfsr_tag_hasdiverged(tag_)) {
alt &= ~LFSR_TAG_R;
}
// prune?
// <b >b
// .-'| .-'|
// <y | | |
// .-------'| | | |
// | <r | => | <b
// | .----' | .-----------|-'|
// | | <b | <b |
// | | .----'| | .----'| |
// 1 2 3 4 4 1 2 3 4 4 2
if (lfsr_tag_prune2(
alt, weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid,
lower_tag, upper_tag)) {
if (lfsr_tag_isred(p_alts[0])) {
alt = p_alts[0] & ~LFSR_TAG_R;
weight = p_weights[0];
branch_ = jump;
jump = p_jumps[0];
lfsr_rbyd_p_pop(p_alts, p_weights, p_jumps);
} else {
branch = jump;
continue;
}
}
// two reds makes a yellow, split?
if (lfsr_tag_isred(alt) && lfsr_tag_isred(p_alts[0])) {
LFS_ASSERT(lfsr_tag_isparallel(alt, p_alts[0]));
// if we take the red or yellow alt we can just point
// to the black alt
// <y >b
// .-------'| .-'|
// | <r | >b
// | .----'| => .-----|-'|
// | | <b | <b |
// | | .-'| | .-'| |
// 1 2 3 4 1 2 3 4 1
if (lfsr_tag_follow2(
alt, weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid,
rid_, tag_)) {
lfsr_tag_flip2(&alt, &weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid);
lfs_swap32(&jump, &branch_);
lfs_swap16(&p_alts[0], &alt);
lfs_swap32(&p_weights[0], &weight);
lfs_swap32(&p_jumps[0], &jump);
alt &= ~LFSR_TAG_R;
lfsr_tag_trim(
p_alts[0], p_weights[0],
&lower_rid, &upper_rid,
&lower_tag, &upper_tag);
lfsr_rbyd_p_red(p_alts, p_weights, p_jumps);
// otherwise we need to point to the yellow alt and
// prune later
// <b
// .-'|
// <y <y |
// .-------'| .-------'| |
// | <r => | <r |
// | .----'| | .----' |
// | | <b | | <b
// | | .-'| | | .----'|
// 1 2 3 4 1 2 3 4 4
} else {
LFS_ASSERT(graft != 0);
p_alts[0] = alt;
p_weights[0] += weight;
p_jumps[0] = graft;
lfsr_tag_trim(
p_alts[0], p_weights[0],
&lower_rid, &upper_rid,
&lower_tag, &upper_tag);
lfsr_rbyd_p_red(p_alts, p_weights, p_jumps);
branch = branch_;
continue;
}
}
// take black alt? needs a flip
// <b >b
// .-'| => .-'|
// 1 2 1 2 1
if (lfsr_tag_isblack(alt)
&& lfsr_tag_follow2(
alt, weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid,
rid_, tag_)) {
lfsr_tag_flip2(&alt, &weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid);
lfs_swap32(&jump, &branch_);
}
// should've taken red alt? needs a flip
// <r >r
// .----'| .-'|
// | <b => | >b
// | .-'| .--|-'|
// 1 2 3 1 2 3 1
if (lfsr_tag_isred(p_alts[0])
&& lfsr_tag_follow(p_alts[0], p_weights[0],
lower_rid, upper_rid,
rid_, tag_)) {
lfs_swap16(&p_alts[0], &alt);
lfs_swap32(&p_weights[0], &weight);
lfs_swap32(&p_jumps[0], &jump);
p_alts[0] |= LFSR_TAG_R;
alt &= ~LFSR_TAG_R;
lfsr_tag_flip2(&alt, &weight,
p_alts[0], p_weights[0],
lower_rid, upper_rid);
lfs_swap32(&jump, &branch_);
}
// trim alt from our current bounds
if (lfsr_tag_isblack(alt)) {
lfsr_tag_trim2(
alt, weight,
p_alts[0], p_weights[0],
&lower_rid, &upper_rid,
&lower_tag, &upper_tag);
}
// continue to next alt
graft = branch;
branch = branch_;
// prune inner alts if our tags diverged
if (lfsr_tag_hasdiverged(tag_)
&& lfsr_tag_isdivergedupper(tag_) != lfsr_tag_isgt(alt)) {
continue;
}
// push alt onto our queue
int err = lfsr_rbyd_p_push(lfs, rbyd,
p_alts, p_weights, p_jumps,
alt, weight, jump);
if (err) {
return err;
}
// found end of tree?
} else {
// update the found tag/rid
//
// note we:
// - clear valid bit, marking the tag as found
// - preserve diverged state
tag_ = lfsr_tag_mode(tag_ & ~LFSR_TAG_RM) | alt;
// done?
if (!lfsr_tag_hasdiverged(tag_) || !lfsr_tag_isrm(other_tag_)) {
break;
}
}
// switch to the other path if we have diverged
if (lfsr_tag_hasdiverged(tag_) || !lfsr_tag_isalt(alt)) {
lfs_swap16(&tag_, &other_tag_);
lfs_sswap32(&rid_, &other_rid_);
lfs_swap32(&branch, &other_branch);
lfs_sswap32(&lower_rid, &other_lower_rid);
lfs_sswap32(&upper_rid, &other_upper_rid);
lfs_swap16(&lower_tag, &other_lower_tag);
lfs_swap16(&upper_tag, &other_upper_tag);
}
}
// the last alt should always end up black
LFS_ASSERT(lfsr_tag_isblack(p_alts[0]));
// if we diverged, merge the bounds
LFS_ASSERT(!lfsr_tag_isrm(tag_));
LFS_ASSERT(!lfsr_tag_hasdiverged(tag_) || !lfsr_tag_isrm(other_tag_));
if (lfsr_tag_hasdiverged(tag_)) {
if (lfsr_tag_isdivergedlower(tag_)) {
// finished on lower path
tag_ = other_tag_;
branch = other_branch;
upper_rid = other_upper_rid;
} else {
// finished on upper path
lower_rid = other_lower_rid;
}
}
// split leaf nodes?
//
// note we bias the weights here so that lfsr_rbyd_lookupnext
// always finds the next biggest tag
//
// note also if lfsr_tag_key(tag_) is null, we found a removed tag that
// we should just prune
//
// this gets real messy because we have a lot of special behavior built in:
// - default => split if tags mismatch
// - delta > 0, !grow => split if tags mismatch or we're inserting a new tag
// - wide-bit set => split if suptype of tags mismatch
// - rm-bit set => never split, but emit alt-always tags, making our
// tag effectively unreachable
//
lfsr_tag_t alt = 0;
lfsr_rid_t weight = 0;
if (lfsr_tag_key(tag_)
&& (upper_rid-1 < rid-lfs_smax32(-delta, 0)
|| (upper_rid-1 == rid-lfs_smax32(-delta, 0)
&& ((delta > 0 && !lfsr_tag_isgrow(tag))
|| (!lfsr_tag_issupwide(tag)
&& lfsr_tag_supkey(tag_) < lfsr_tag_supkey(tag))
|| (!lfsr_tag_issupwide(tag)
&& !lfsr_tag_issubwide(tag)
&& lfsr_tag_key(tag_) < lfsr_tag_key(tag)))))) {
if (lfsr_tag_isrm(tag) || !lfsr_tag_key(tag)) {
// if removed, make our tag unreachable
alt = LFSR_TAG_ALT(GT, B, 0);
weight = upper_rid - lower_rid + delta;
upper_rid -= weight;
} else {
// split less than
alt = LFSR_TAG_ALT(
LE,
TAG((!lfsr_tag_hasdiverged(tag_))
? LFSR_TAG_R
: LFSR_TAG_B),
lfsr_tag_key(tag_));
weight = upper_rid - lower_rid;
lower_rid += weight;
}
} else if (lfsr_tag_key(tag_)
&& (upper_rid-1 > rid
|| (upper_rid-1 == rid
&& ((delta > 0 && !lfsr_tag_isgrow(tag))
|| (!lfsr_tag_issupwide(tag)
&& lfsr_tag_supkey(tag_) > lfsr_tag_supkey(tag))
|| (!lfsr_tag_issupwide(tag)
&& !lfsr_tag_issubwide(tag)
&& lfsr_tag_key(tag_) > lfsr_tag_key(tag)))))) {
if (lfsr_tag_isrm(tag) || !lfsr_tag_key(tag)) {
// if removed, make our tag unreachable
alt = LFSR_TAG_ALT(GT, B, 0);
weight = upper_rid - lower_rid + delta;
upper_rid -= weight;
} else {
// split greater than
alt = LFSR_TAG_ALT(
GT,
TAG((!lfsr_tag_hasdiverged(tag_))
? LFSR_TAG_R
: LFSR_TAG_B),
lfsr_tag_key(tag));
weight = upper_rid - (rid+1);
upper_rid -= weight;
}
}
if (alt) {
int err = lfsr_rbyd_p_push(lfs, rbyd,
p_alts, p_weights, p_jumps,
alt, weight, branch);
if (err) {
return err;
}
if (lfsr_tag_isred(p_alts[0])) {
// introduce a red edge
lfsr_rbyd_p_red(p_alts, p_weights, p_jumps);
}
}
// flush any pending alts
int err = lfsr_rbyd_p_flush(lfs, rbyd,
p_alts, p_weights, p_jumps, 3);
if (err) {
return err;
}
leaf:;
// write the actual tag
//
// note we always need a non-alt to terminate the trunk, otherwise we
// can't find trunks during fetch
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->blocks[0], rbyd->eoff,
// mark as shrub if we are a shrub
(lfsr_rbyd_isshrub(rbyd) ? LFSR_TAG_SHRUB : 0)
// rm => null, otherwise strip off control bits
| ((lfsr_tag_isrm(tag))
? LFSR_TAG_NULL
: lfsr_tag_key(tag)),
upper_rid - lower_rid + delta,
lfsr_data_size(&data),
&rbyd->cksum);
if (d < 0) {
return d;
}
rbyd->eoff += d;
// don't forget the data!
err = lfsr_bd_progdata(lfs, rbyd->blocks[0], rbyd->eoff, data,
&rbyd->cksum, NULL);
if (err) {
return err;
}
rbyd->eoff += lfsr_data_size(&data);
return 0;
}
static int lfsr_rbyd_appendcksum(lfs_t *lfs, lfsr_rbyd_t *rbyd) {
// must fetch before mutating!
LFS_ASSERT(lfsr_rbyd_isfetched(rbyd));
// we can't do anything if we're not erased
if (rbyd->eoff >= lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
// make sure every rbyd starts with its revision count
if (rbyd->eoff == 0) {
int err = lfsr_rbyd_appendrev(lfs, rbyd, 0);
if (err) {
return err;
}
}
// align to the next prog unit
//
// this gets a bit complicated as we have two types of cksums:
//
// - 9-word cksum with ecksum to check following prog (middle of block)
// - ecksum tag type => 2 byte le16
// - ecksum tag rid => 1 byte leb128
// - ecksum tag size => 1 byte leb128 (worst case)
// - ecksum crc32c => 4 byte le32
// - ecksum size => 5 byte leb128 (worst case)
// - cksum tag type => 2 byte le16
// - cksum tag rid => 1 byte leb128
// - cksum tag size => 5 byte leb128 (worst case)
// - cksum crc32c => 4 byte le32
// => 25 bytes total
//
// - 4-word cksum with no following prog (end of block)
// - cksum tag type => 2 byte le16
// - cksum tag rid => 1 byte leb128
// - cksum tag size => 5 byte leb128 (worst case)
// - cksum crc32c => 4 byte le32
// => 12 bytes total
//
lfs_size_t aligned_eoff = lfs_alignup(
rbyd->eoff + 2+1+1+4+5 + 2+1+5+4,
lfs->cfg->prog_size);
// space for ecksum?
uint8_t perturb = 0;
if (aligned_eoff < lfs->cfg->block_size) {
// read the leading byte in case we need to change the expected
// value of the next tag's valid bit
int err = lfsr_bd_read(lfs,
rbyd->blocks[0], aligned_eoff, lfs->cfg->prog_size,
&perturb, 1);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// find the expected ecksum, don't bother avoiding a reread of the
// perturb byte, as it should still be in our cache
lfsr_ecksum_t ecksum = {.size=lfs->cfg->prog_size};
err = lfsr_bd_cksum(lfs,
rbyd->blocks[0], aligned_eoff, ecksum.size,
ecksum.size,
&ecksum.cksum);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
uint8_t ecksum_buf[LFSR_ECKSUM_DSIZE];
lfsr_data_t ecksum_data = lfsr_data_fromecksum(&ecksum, ecksum_buf);
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->blocks[0], rbyd->eoff,
LFSR_TAG_ECKSUM, 0, lfsr_data_size(&ecksum_data),
&rbyd->cksum);
if (d < 0) {
return d;
}
rbyd->eoff += d;
err = lfsr_bd_progdata(lfs, rbyd->blocks[0], rbyd->eoff, ecksum_data,
&rbyd->cksum, NULL);
if (err) {
return err;
}
rbyd->eoff += lfsr_data_size(&ecksum_data);
// at least space for a cksum?
} else if (rbyd->eoff + 2+1+5+4 <= lfs->cfg->block_size) {
// note this implicitly marks the rbyd as unerased
aligned_eoff = lfs->cfg->block_size;
// not even space for a cksum? we can't finish the commit
} else {
return LFS_ERR_RANGE;
}
// build end-of-commit cksum
//
// note padding-size depends on leb-encoding depends on padding-size, to
// get around this catch-22 we just always write a fully-expanded leb128
// encoding
uint8_t cksum_buf[2+1+5+4];
cksum_buf[0] = (LFSR_TAG_CKSUM >> 8) | ((lfs_popc(rbyd->cksum) & 1) << 7);
cksum_buf[1] = 0;
cksum_buf[2] = 0;
lfs_size_t padding = aligned_eoff - (rbyd->eoff + 2+1+5);
cksum_buf[3] = 0x80 | (0x7f & (padding >> 0));
cksum_buf[4] = 0x80 | (0x7f & (padding >> 7));
cksum_buf[5] = 0x80 | (0x7f & (padding >> 14));
cksum_buf[6] = 0x80 | (0x7f & (padding >> 21));
cksum_buf[7] = 0x00 | (0x7f & (padding >> 28));
rbyd->cksum = lfs_crc32c(rbyd->cksum, cksum_buf, 2+1+5);
// we can't let the next tag appear as valid, so intentionally perturb the
// commit if this happens, note parity(crc(m)) == parity(m) with crc32c,
// so we can really change any bit to make this happen, we've reserved a bit
// in cksum tags just for this purpose
if ((lfs_popc(rbyd->cksum) & 1) == (perturb >> 7)) {
cksum_buf[1] ^= 0x01;
rbyd->cksum ^= 0x68032cc8; // note crc(a ^ b) == crc(a) ^ crc(b)
}
lfs_tole32_(rbyd->cksum, &cksum_buf[2+1+5]);
int err = lfsr_bd_prog(lfs, rbyd->blocks[0], rbyd->eoff,
cksum_buf, 2+1+5+4,
NULL, NULL);
if (err) {
return err;
}
rbyd->eoff += 2+1+5+4;
// flush our caches, finalizing the commit on-disk
err = lfsr_bd_sync(lfs);
if (err) {
return err;
}
rbyd->eoff = aligned_eoff;
return 0;
}
static int lfsr_rbyd_appendattrs(lfs_t *lfs,
lfsr_rbyd_t *rbyd, lfsr_srid_t rid,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// append each tag to the tree
for (lfs_size_t i = 0; i < attr_count; i++) {
// don't write tags outside of the requested range
lfsr_srid_t rid_ = rid + (
(!lfsr_tag_isgrow(attrs[i].tag) && attrs[i].delta > 0)
? 1 : 0);
if (rid_ >= start_rid
// note the use of rid+1 and unsigned comparison here to
// treat end_rid=-1 as "unbounded" in such a way that rid=-1
// is still included
&& (lfs_size_t)(rid_ + 1) <= (lfs_size_t)end_rid) {
int err = lfsr_rbyd_appendattr(lfs, rbyd,
rid - lfs_smax32(start_rid, 0),
attrs[i].tag, attrs[i].delta, attrs[i].data);
if (err) {
return err;
}
}
// we need to make sure we keep start_rid/end_rid updated with
// weight changes
if (rid_ < start_rid) {
start_rid += attrs[i].delta;
}
if (rid_ < end_rid) {
end_rid += attrs[i].delta;
}
// adjust rid
rid += attrs[i].delta;
}
return 0;
}
static int lfsr_rbyd_commit(lfs_t *lfs,
lfsr_rbyd_t *rbyd, lfsr_srid_t rid,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// append each tag to the tree
int err = lfsr_rbyd_appendattrs(lfs, rbyd, rid, -1, -1,
attrs, attr_count);
if (err) {
return err;
}
// append a cksum, finalizing the commit
err = lfsr_rbyd_appendcksum(lfs, rbyd);
if (err) {
return err;
}
return 0;
}
// determine the upper-bound cost of a single rbyd attr after compaction
//
// note that with rebalancing during compaction, we know the number
// of inner nodes is roughly the same as the number of tags. Each node
// has two alts and is terminated by a 4-byte null tag.
//
#define LFSR_ATTR_ESTIMATE (3*LFSR_TAG_DSIZE + 4)
// Calculate the maximum possible disk usage required by this rbyd after
// compaction. This uses a conservative estimate so the actual on-disk cost
// should be smaller.
//
// This also returns a good split_rid in case the rbyd needs to be split.
//
// TODO do we need to include commit overhead here?
static lfs_ssize_t lfsr_rbyd_estimate(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
lfsr_srid_t *split_rid_) {
// calculate dsize by starting from the outside ids and working inwards,
// this naturally gives us a split rid
//
// TODO adopt this a/b naming scheme in lfsr_rbyd_appendattr?
lfsr_srid_t rid = start_rid;
lfsr_srid_t other_rid = lfs_min32(rbyd->weight, end_rid);
lfs_size_t dsize = 0;
lfs_size_t other_dsize = 0;
lfs_size_t rbyd_dsize = 0;
while (rid != other_rid) {
if (dsize > other_dsize
// bias so lower dsize >= upper dsize
|| (dsize == other_dsize && rid > other_rid)) {
lfs_sswap32(&rid, &other_rid);
lfs_swap32(&dsize, &other_dsize);
}
if (rid > other_rid) {
rid -= 1;
}
lfsr_tag_t tag = 0;
lfsr_rid_t weight = 0;
lfs_size_t dsize_ = 0;
while (true) {
lfsr_srid_t rid_;
lfsr_rid_t weight_;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, rbyd,
rid, tag+1,
&rid_, &tag, &weight_, &data);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
LFS_ASSERT(err < 0);
return err;
}
if (rid_ > rid+lfs_smax32(weight_-1, 0)) {
break;
}
// keep track of rid and weight
rid = rid_;
weight += weight_;
// include the cost of this tag
dsize_ += LFSR_ATTR_ESTIMATE + lfsr_data_size(&data);
}
if (rid == -1) {
rbyd_dsize += dsize_;
} else {
dsize += dsize_;
}
if (rid < other_rid) {
rid += 1;
} else {
rid -= lfs_smax32(weight-1, 0);
}
}
if (split_rid_) {
*split_rid_ = rid;
}
return rbyd_dsize + dsize + other_dsize;
}
// appends a raw tag as a part of compaction, note these must
// be appended in order!
//
// also note the direct use of weight instead of delta here
static int lfsr_rbyd_appendcompactattr(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfsr_tag_t tag, lfsr_rid_t weight, lfsr_data_t data) {
// TODO deduplicate this? rbyd_preparemutation or something?
// must fetch before mutating!
LFS_ASSERT(lfsr_rbyd_isfetched(rbyd));
// we can't do anything if we're not erased
if (rbyd->eoff >= lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
// make sure every rbyd starts with a revision count
if (rbyd->eoff == 0) {
int err = lfsr_rbyd_appendrev(lfs, rbyd, 0);
if (err) {
return err;
}
}
// write the tag
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->blocks[0], rbyd->eoff,
// mark as shrub if we are a shrub
(lfsr_rbyd_isshrub(rbyd) ? LFSR_TAG_SHRUB : 0)
| tag,
weight, lfsr_data_size(&data),
&rbyd->cksum);
if (d < 0) {
return d;
}
rbyd->eoff += d;
// and the data
int err = lfsr_bd_progdata(lfs, rbyd->blocks[0], rbyd->eoff, data,
&rbyd->cksum, NULL);
if (err) {
return err;
}
rbyd->eoff += lfsr_data_size(&data);
// keep track of the total weight, the rbyd is in an unusable
// state until lfsr_rbyd_appendcompaction anyways
rbyd->weight += weight;
return 0;
}
static int lfsr_rbyd_appendcompactrbyd(lfs_t *lfs, lfsr_rbyd_t *rbyd_,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
const lfsr_rbyd_t *rbyd) {
// copy over tags in the rbyd in order
lfsr_srid_t rid = start_rid;
lfsr_tag_t tag = 0;
while (true) {
lfsr_rid_t weight;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, rbyd,
rid, tag+1,
&rid, &tag, &weight, &data);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
// end of range? note the use of rid+1 and unsigned comparison here to
// treat end_rid=-1 as "unbounded" in such a way that rid=-1 is still
// included
if ((lfs_size_t)(rid + 1) > (lfs_size_t)end_rid) {
break;
}
// write the tag
err = lfsr_rbyd_appendcompactattr(lfs, rbyd_, tag, weight, data);
if (err) {
return err;
}
}
return 0;
}
static int lfsr_rbyd_appendcompaction(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_size_t off) {
// must fetch before mutating!
LFS_ASSERT(lfsr_rbyd_isfetched(rbyd));
// clamp offset to be after the revision count
off = lfs_max32(off, sizeof(uint32_t));
// make sure every rbyd starts with a revision count
if (rbyd->eoff == 0) {
int err = lfsr_rbyd_appendrev(lfs, rbyd, 0);
if (err) {
return err;
}
}
// empty rbyd? write a null tag so our trunk can still point to something
if (rbyd->eoff == off) {
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->blocks[0], rbyd->eoff,
// mark as shrub if we are a shrub
(lfsr_rbyd_isshrub(rbyd) ? LFSR_TAG_SHRUB : 0)
| LFSR_TAG_NULL,
0, 0,
&rbyd->cksum);
if (d < 0) {
return d;
}
rbyd->eoff += d;
rbyd->trunk = (rbyd->trunk & LFSR_RBYD_SHRUB) | off;
rbyd->weight = 0;
return 0;
}
// connect every other trunk together, building layers of a perfectly
// balanced binary tree upwards until we have a single trunk
lfs_size_t layer = off;
lfsr_rid_t weight = 0;
while (true) {
lfs_size_t layer_ = rbyd->eoff;
off = layer;
while (off < layer_) {
// connect two trunks together with a new binary trunk
for (int i = 0; i < 2 && off < layer_; i++) {
lfs_size_t trunk = off;
lfsr_tag_t tag = 0;
weight = 0;
while (true) {
lfsr_tag_t tag__;
lfsr_rid_t weight__;
lfs_size_t size__;
lfs_ssize_t d = lfsr_bd_readtag(lfs,
rbyd->blocks[0], off, layer_ - off,
&tag__, &weight__, &size__, NULL);
if (d < 0) {
return d;
}
off += d;
// skip any data
if (!lfsr_tag_isalt(tag__)) {
off += size__;
}
// ignore shrub trunks, unless we are actually compacting
// a shrub tree
if (!lfsr_rbyd_isshrub(rbyd)
&& lfsr_tag_isshrub(tag__)) {
trunk = off;
weight = 0;
continue;
}
// keep track of trunk's trunk and weight
weight += weight__;
// keep track of the last non-null tag in our trunk.
// Because of how we construct each layer, the last
// non-null tag is the largest tag in that part of
// the tree
if (tag__ & ~LFSR_TAG_SHRUB) {
tag = tag__;
}
// did we hit a tag that terminates our trunk?
if (!lfsr_tag_isalt(tag__)) {
break;
}
}
// do we only have one trunk? we must be done
if (trunk == layer && off >= layer_) {
goto done;
}
// connect with an altle
lfs_ssize_t d = lfsr_bd_progtag(lfs,
rbyd->blocks[0], rbyd->eoff,
LFSR_TAG_ALT(LE, B, lfsr_tag_key(tag)),
weight,
rbyd->eoff - trunk,
&rbyd->cksum);
if (d < 0) {
return d;
}
rbyd->eoff += d;
}
// terminate with a null tag
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->blocks[0], rbyd->eoff,
// mark as shrub if we are a shrub
(lfsr_rbyd_isshrub(rbyd) ? LFSR_TAG_SHRUB : 0)
| LFSR_TAG_NULL,
0, 0,
&rbyd->cksum);
if (d < 0) {
return d;
}
rbyd->eoff += d;
}
layer = layer_;
}
done:;
// done! just need to update our trunk. Note we could have no trunks
// after compaction. Leave this to upper layers to take care of this.
rbyd->trunk = (rbyd->trunk & LFSR_RBYD_SHRUB) | layer;
rbyd->weight = weight;
return 0;
}
static int lfsr_rbyd_compact(lfs_t *lfs, lfsr_rbyd_t *rbyd_,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
const lfsr_rbyd_t *rbyd) {
// append rbyd
int err = lfsr_rbyd_appendcompactrbyd(lfs, rbyd_, start_rid, end_rid,
rbyd);
if (err) {
return err;
}
// compact
err = lfsr_rbyd_appendcompaction(lfs, rbyd_, 0);
if (err) {
return err;
}
return 0;
}
// append and consume any pending gstate
static int lfsr_rbyd_appendgdelta(lfs_t *lfs, lfsr_rbyd_t *rbyd) {
// need grm delta?
if (!lfsr_grm_iszero(lfs->grm_d)) {
// calculate our delta
uint8_t grm_buf[LFSR_GRM_DSIZE];
memset(grm_buf, 0, LFSR_GRM_DSIZE);
lfsr_data_t data;
int err = lfsr_rbyd_lookup(lfs, rbyd, -1, LFSR_TAG_GRMDELTA,
&data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
lfs_ssize_t grm_dsize = lfsr_data_read(lfs, &data,
grm_buf, LFSR_GRM_DSIZE);
if (grm_dsize < 0) {
return grm_dsize;
}
}
err = lfsr_grm_xor(lfs, grm_buf, LFSR_DATA_BUF(
&lfs->grm_d, LFSR_GRM_DSIZE));
if (err) {
return err;
}
// append to our rbyd, note this replaces the original delta
lfs_size_t size = lfsr_grm_size(grm_buf);
err = lfsr_rbyd_appendattr(lfs, rbyd, -1,
// opportunistically remove this tag if delta is all zero
(size == 0) ? LFSR_TAG_RM(GRMDELTA) : LFSR_TAG_GRMDELTA, 0,
LFSR_DATA_BUF(grm_buf, size));
if (err) {
return err;
}
}
return 0;
}
// append a secondary "shrub" tree
static int lfsr_rbyd_appendshrub(lfs_t *lfs, lfsr_rbyd_t *rbyd,
const lfsr_shrub_t *shrub) {
// keep track of the start of the new tree
lfs_size_t off = rbyd->eoff;
// mark as shrub
rbyd->trunk |= LFSR_RBYD_SHRUB;
// compact our shrub
int err = lfsr_rbyd_appendcompactrbyd(lfs, rbyd, -1, -1, shrub);
if (err) {
return err;
}
err = lfsr_rbyd_appendcompaction(lfs, rbyd, off);
if (err) {
return err;
}
return 0;
}
// some low-level name things
//
// names in littlefs are tuples of directory-ids + ascii/utf8 strings
// binary search an rbyd for a name, leaving the rid_/tag_/weight_/data_
// with the best matching name if not found
static lfs_scmp_t lfsr_rbyd_namelookup(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfsr_did_t did, const char *name, lfs_size_t name_size,
lfsr_srid_t *rid_,
lfsr_tag_t *tag_, lfsr_rid_t *weight_, lfsr_data_t *data_) {
// empty rbyd? leave it up to upper layers to handle this
if (rbyd->weight == 0) {
return LFS_ERR_NOENT;
}
// binary search for our name
lfsr_srid_t lower = 0;
lfsr_srid_t upper = rbyd->weight;
lfs_scmp_t cmp;
while (lower < upper) {
lfsr_tag_t tag__;
lfsr_srid_t rid__;
lfsr_rid_t weight__;
lfsr_data_t data__;
int err = lfsr_rbyd_lookupnext(lfs, rbyd,
// lookup ~middle rid, note we may end up in the middle
// of a weighted rid with this
lower + (upper-1-lower)/2, 0,
&rid__, &tag__, &weight__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
LFS_ASSERT(err < 0);
return err;
}
// if we have no name, treat this rid as always lt
if (lfsr_tag_suptype(tag__) != LFSR_TAG_NAME) {
cmp = LFS_CMP_LT;
// compare names
} else {
cmp = lfsr_data_namecmp(lfs, &data__, did, name, name_size);
if (cmp < 0) {
return cmp;
}
}
// bisect search space
if (lfs_cmp(cmp) > 0) {
upper = rid__ - (weight__-1);
// only keep track of best-match rids > our target if we haven't
// seen an rid < our target
if (lower == 0) {
if (rid_) {
*rid_ = rid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
}
} else if (lfs_cmp(cmp) < 0) {
lower = rid__ + 1;
// keep track of best-matching rid < our target
if (rid_) {
*rid_ = rid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
} else {
// found a match?
if (rid_) {
*rid_ = rid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
return LFS_CMP_EQ;
}
}
// no match, return if found name was lt/gt expect
//
// this will always be lt unless all rids are gt
return (lower == 0) ? LFS_CMP_GT : LFS_CMP_LT;
}
/// B-tree operations ///
// convenience operations
static inline int lfsr_btree_cmp(
const lfsr_btree_t *a,
const lfsr_btree_t *b) {
return lfsr_rbyd_cmp(a, b);
}
// branch on-disk encoding
#define LFSR_BRANCH_DSIZE (5+5+4)
// 2 leb128 + 1 crc32c => 14 bytes (worst case)
#define LFSR_DATA_FROMBRANCH(_branch, _buffer) \
lfsr_data_frombranch(_branch, _buffer)
static lfsr_data_t lfsr_data_frombranch(const lfsr_rbyd_t *branch,
uint8_t buffer[static LFSR_BRANCH_DSIZE]) {
lfs_ssize_t d = 0;
lfs_ssize_t d_ = lfs_toleb128(branch->blocks[0], &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
d_ = lfs_toleb128(lfsr_rbyd_trunk(branch), &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
lfs_tole32_(branch->cksum, &buffer[d]);
d += 4;
return LFSR_DATA_BUF(buffer, d);
}
static int lfsr_data_readbranch(lfs_t *lfs, lfsr_data_t *data,
lfsr_bid_t weight,
lfsr_rbyd_t *branch) {
// setting off to 0 here will trigger asserts if we try to append
// without fetching first
branch->eoff = 0;
branch->weight = weight;
int err = lfsr_data_readleb128(lfs, data, (int32_t*)&branch->blocks[0]);
if (err) {
return err;
}
err = lfsr_data_readleb128(lfs, data, &branch->trunk);
if (err) {
return err;
}
err = lfsr_data_readle32(lfs, data, &branch->cksum);
if (err) {
return err;
}
return 0;
}
// btree on-disk encoding
//
// this is the same as the branch on-disk econding, but prefixed with the
// btree's weight
// 3 leb128 + 1 crc32c => 19 bytes (worst case)
#define LFSR_BTREE_DSIZE (5+LFSR_BRANCH_DSIZE)
#define LFSR_DATA_FROMBTREE(_btree, _buffer) \
lfsr_data_frombtree(_btree, _buffer)
static lfsr_data_t lfsr_data_frombtree(const lfsr_btree_t *btree,
uint8_t buffer[static LFSR_BTREE_DSIZE]) {
lfs_ssize_t d = 0;
lfs_ssize_t d_ = lfs_toleb128(btree->weight, &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
lfsr_data_t data = lfsr_data_frombranch(btree, &buffer[d]);
d += lfsr_data_size(&data);
return LFSR_DATA_BUF(buffer, d);
}
static int lfsr_data_readbtree(lfs_t *lfs, lfsr_data_t *data,
lfsr_btree_t *btree) {
lfsr_bid_t weight;
int err = lfsr_data_readleb128(lfs, data, (int32_t*)&weight);
if (err) {
return err;
}
err = lfsr_data_readbranch(lfs, data, weight, btree);
if (err) {
return err;
}
return 0;
}
// core btree operations
static int lfsr_btree_alloc(lfs_t *lfs, lfsr_btree_t *btree) {
return lfsr_rbyd_alloc(lfs, btree);
}
static int lfsr_btree_lookupnext_(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_bid_t bid,
lfsr_bid_t *bid_, lfsr_rbyd_t *rbyd_, lfsr_srid_t *rid_,
lfsr_tag_t *tag_, lfsr_bid_t *weight_, lfsr_data_t *data_) {
// descend down the btree looking for our bid
lfsr_rbyd_t branch = *btree;
lfsr_srid_t rid = bid;
while (true) {
// each branch is a pair of optional name + on-disk structure
lfsr_srid_t rid__;
lfsr_tag_t tag__;
lfsr_rid_t weight__;
lfsr_data_t data__;
int err = lfsr_rbyd_lookupnext(lfs, &branch, rid, 0,
&rid__, &tag__, &weight__, &data__);
if (err) {
return err;
}
if (lfsr_tag_suptype(tag__) == LFSR_TAG_NAME) {
err = lfsr_rbyd_sublookup(lfs, &branch, rid__, LFSR_TAG_STRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// found another branch
if (tag__ == LFSR_TAG_BRANCH) {
// adjust rid with subtree's weight
rid -= (rid__ - (weight__-1));
// fetch the next branch
err = lfsr_data_readbranch(lfs, &data__, weight__, &branch);
if (err) {
return err;
}
// found our bid
} else {
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = bid + (rid__ - rid);
}
if (rbyd_) {
*rbyd_ = branch;
}
if (rid_) {
*rid_ = rid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
return 0;
}
}
}
static int lfsr_btree_lookupnext(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_bid_t bid,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bid_t *weight_,
lfsr_data_t *data_) {
return lfsr_btree_lookupnext_(lfs, btree, bid,
bid_, NULL, NULL, tag_, weight_, data_);
}
static int lfsr_btree_lookup(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_bid_t bid,
lfsr_tag_t *tag_, lfsr_bid_t *weight_, lfsr_data_t *data_) {
lfsr_bid_t bid_;
int err = lfsr_btree_lookupnext(lfs, btree, bid,
&bid_, tag_, weight_, data_);
if (err) {
return err;
}
// lookup finds the next-smallest bid, all we need to do is fail if it
// picks up the wrong bid
if (bid_ != bid) {
return LFS_ERR_NOENT;
}
return 0;
}
// TODO should lfsr_btree_lookupnext/lfsr_btree_parent be deduplicated?
static int lfsr_btree_parent(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_bid_t bid, const lfsr_rbyd_t *child,
lfsr_rbyd_t *rbyd_, lfsr_srid_t *rid_) {
// we should only call this when we actually have parents
LFS_ASSERT(bid < (lfsr_bid_t)btree->weight);
LFS_ASSERT(lfsr_rbyd_cmp(btree, child) != 0);
// descend down the btree looking for our rid
lfsr_rbyd_t branch = *btree;
lfsr_srid_t rid = bid;
while (true) {
// each branch is a pair of optional name + on-disk structure
lfsr_srid_t rid__;
lfsr_tag_t tag__;
lfsr_rid_t weight__;
lfsr_data_t data__;
int err = lfsr_rbyd_lookupnext(lfs, &branch, rid, 0,
&rid__, &tag__, &weight__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
if (lfsr_tag_suptype(tag__) == LFSR_TAG_NAME) {
err = lfsr_rbyd_sublookup(lfs, &branch, rid__, LFSR_TAG_STRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// didn't find our child?
if (tag__ != LFSR_TAG_BRANCH) {
return LFS_ERR_NOENT;
}
// adjust rid with subtree's weight
rid -= (rid__ - (weight__-1));
// fetch the next branch
lfsr_rbyd_t branch_;
err = lfsr_data_readbranch(lfs, &data__, weight__, &branch_);
if (err) {
return err;
}
// found our child?
if (lfsr_rbyd_cmp(&branch_, child) == 0) {
// TODO how many of these should be conditional?
if (rbyd_) {
*rbyd_ = branch;
}
if (rid_) {
*rid_ = rid__;
}
return 0;
}
branch = branch_;
}
}
// core btree algorithm
//
// this commits up to the root, but stops if:
// 1. we need a new root
// 2. we have a shrub root
//
static int lfsr_btree_commit_(lfs_t *lfs, lfsr_btree_t *btree,
lfsr_bid_t *bid_, const lfsr_attr_t **attrs_, lfs_size_t *attr_count_,
lfsr_attr_t attrs__[static 4],
uint8_t buf__[static 2*LFSR_BRANCH_DSIZE]) {
lfsr_bid_t bid = *bid_;
LFS_ASSERT((lfsr_sbid_t)bid < btree->weight);
const lfsr_attr_t *attrs = *attrs_;
lfs_size_t attr_count = *attr_count_;
// lookup in which leaf our bids resides
//
// for lfsr_btree_commit operations to work out, we need to
// limit our bid to an rid in the tree, which is what this min
// is doing
lfsr_rbyd_t rbyd = *btree;
lfsr_srid_t rid = bid;
if (btree->weight > 0) {
lfsr_srid_t rid_;
int err = lfsr_btree_lookupnext_(lfs, btree,
lfs_min32(bid, btree->weight-1),
&bid, &rbyd, &rid_, NULL, NULL, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// adjust bid to point to the zero-most rid
bid -= rid_;
rid -= bid;
}
// tail-recursively commit to btree
while (true) {
// we will always need our parent, so go ahead and find it
lfsr_rbyd_t parent = {.trunk=0, .weight=0};
lfsr_srid_t pid = -1;
// are we root?
if (rbyd.blocks[0] == btree->blocks[0]
|| !lfsr_rbyd_hastrunk(&rbyd)) {
// new root? shrub root? yield the final root commit to
// higher-level btree/bshrub logic
if (!lfsr_rbyd_hastrunk(&rbyd)
|| lfsr_rbyd_isshrub(btree)) {
*bid_ = rid;
*attrs_ = attrs;
*attr_count_ = attr_count;
return (!lfsr_rbyd_hastrunk(&rbyd)) ? LFS_ERR_RANGE : 0;
}
// mark btree as unerased in case of failure, our btree rbyd and
// root rbyd can diverge if there's a split, but we would have
// marked the old root as unerased earlier anyways
btree->eoff = -1;
} else {
int err = lfsr_btree_parent(lfs, btree, bid, &rbyd,
&parent, &pid);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// fetch our rbyd so we can mutate it
//
// note that some paths lead this to being a newly allocated rbyd,
// these will fail to fetch so we need to check that this rbyd is
// unfetched
//
// a funny benefit is we cache the root of our btree this way
if (!lfsr_rbyd_isfetched(&rbyd)) {
int err = lfsr_rbyd_fetchvalidate(lfs, &rbyd,
rbyd.blocks[0], lfsr_rbyd_trunk(&rbyd), rbyd.weight,
rbyd.cksum);
if (err) {
return err;
}
}
// is rbyd erased? can we sneak our commit into any remaining
// erased bytes? note that the btree trunk field prevents this from
// interacting with other references to the rbyd
lfsr_rbyd_t rbyd_ = rbyd;
int err = lfsr_rbyd_appendattrs(lfs, &rbyd_, rid, -1, -1,
attrs, attr_count);
if (err) {
// TODO wait should we also move if there is corruption here?
if (err == LFS_ERR_RANGE) {
goto compact;
}
return err;
}
err = lfsr_rbyd_appendcksum(lfs, &rbyd_);
if (err) {
if (err == LFS_ERR_RANGE) {
goto compact;
}
// TODO wait should we also move if there is corruption here?
return err;
}
finalize:;
// done?
if (!lfsr_rbyd_hastrunk(&parent)) {
*btree = rbyd_;
*attr_count_ = 0;
return 0;
}
// is our parent the root and is the root degenerate?
if (rbyd.weight == btree->weight) {
// collapse the root, decreasing the height of the tree
*btree = rbyd_;
*attr_count_ = 0;
return 0;
}
// prepare commit to parent, tail recursing upwards
//
// note that since we defer merges to compaction time, we can
// end up removing an rbyd here
attr_count = 0;
lfs_size_t buf_size = 0;
bid -= pid - (rbyd.weight-1);
if (rbyd_.weight == 0) {
attrs__[attr_count++] = LFSR_ATTR(
RM, -rbyd.weight, NULL());
} else {
attrs__[attr_count++] = LFSR_ATTR(
BRANCH, 0, FROMBRANCH(&rbyd_, &buf__[buf_size]));
buf_size += LFSR_BRANCH_DSIZE;
if (rbyd_.weight != rbyd.weight) {
attrs__[attr_count++] = LFSR_ATTR(
GROW, -rbyd.weight + rbyd_.weight, NULL());
}
}
attrs = attrs__;
rbyd = parent;
rid = pid;
continue;
compact:;
// estimate our compacted size
lfsr_srid_t split_rid;
lfs_ssize_t estimate = lfsr_rbyd_estimate(lfs, &rbyd, -1, -1,
&split_rid);
if (estimate < 0) {
return estimate;
}
// are we too big? need to split?
if ((lfs_size_t)estimate > lfs->cfg->block_size/2) {
// need to split
goto split;
}
// before we compact, can we merge with our siblings?
lfsr_rbyd_t sibling;
if ((lfs_size_t)estimate <= lfs->cfg->block_size/4
// no parent? can't merge
&& !lfsr_rbyd_hastrunk(&parent)) {
// try the right sibling
if (pid+1 < parent.weight) {
// try looking up the sibling
lfsr_srid_t sibling_rid;
lfsr_tag_t sibling_tag;
lfsr_rid_t sibling_weight;
lfsr_data_t sibling_data;
err = lfsr_rbyd_lookupnext(lfs, &parent,
pid+1, LFSR_TAG_NAME,
&sibling_rid, &sibling_tag, &sibling_weight,
&sibling_data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
if (sibling_tag == LFSR_TAG_NAME) {
err = lfsr_rbyd_sublookup(lfs, &parent,
sibling_rid, LFSR_TAG_STRUCT,
&sibling_tag, &sibling_data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
LFS_ASSERT(sibling_tag == LFSR_TAG_BRANCH);
err = lfsr_data_readbranch(lfs, &sibling_data, sibling_weight,
&sibling);
if (err) {
return err;
}
// estimate if our sibling will fit
lfs_ssize_t sibling_estimate = lfsr_rbyd_estimate(lfs,
&sibling, -1, -1,
NULL);
if (sibling_estimate < 0) {
return sibling_estimate;
}
// fits? try to merge
if ((lfs_size_t)(estimate + sibling_estimate)
< lfs->cfg->block_size/2) {
goto merge;
}
}
// try the left sibling
if (pid-rbyd.weight >= 0) {
// try looking up the sibling
lfsr_srid_t sibling_rid;
lfsr_tag_t sibling_tag;
lfsr_rid_t sibling_weight;
lfsr_data_t sibling_data;
err = lfsr_rbyd_lookupnext(lfs, &parent,
pid-rbyd.weight, LFSR_TAG_NAME,
&sibling_rid, &sibling_tag, &sibling_weight,
&sibling_data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
if (sibling_tag == LFSR_TAG_NAME) {
err = lfsr_rbyd_sublookup(lfs, &parent,
sibling_rid, LFSR_TAG_STRUCT,
&sibling_tag, &sibling_data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
LFS_ASSERT(sibling_tag == LFSR_TAG_BRANCH);
err = lfsr_data_readbranch(lfs, &sibling_data, sibling_weight,
&sibling);
if (err) {
return err;
}
// estimate if our sibling will fit
lfs_ssize_t sibling_estimate = lfsr_rbyd_estimate(lfs,
&sibling, -1, -1,
NULL);
if (sibling_estimate < 0) {
return sibling_estimate;
}
// fits? try to merge
if ((lfs_size_t)(estimate + sibling_estimate)
< lfs->cfg->block_size/2) {
// if we're merging our left sibling, swap our rbyds
// so our sibling is on the right
bid -= sibling.weight;
pid -= rbyd.weight;
rbyd_ = sibling;
sibling = rbyd;
rbyd = rbyd_;
goto merge;
}
}
}
// allocate a new rbyd
err = lfsr_rbyd_alloc(lfs, &rbyd_);
if (err) {
return err;
}
// try to compact
err = lfsr_rbyd_compact(lfs, &rbyd_, -1, -1,
&rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append any pending attrs, it's up to upper
// layers to make sure these always fit
err = lfsr_rbyd_appendattrs(lfs, &rbyd_, rid, -1, -1,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// finalize commit
err = lfsr_rbyd_appendcksum(lfs, &rbyd_);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
goto finalize;
split:;
// we should have something to split here
LFS_ASSERT(split_rid > 0 && split_rid < rbyd.weight);
// allocate a new rbyd
err = lfsr_rbyd_alloc(lfs, &rbyd_);
if (err) {
return err;
}
// allocate a sibling
err = lfsr_rbyd_alloc(lfs, &sibling);
if (err) {
return err;
}
// copy over tags < split_rid
err = lfsr_rbyd_compact(lfs, &rbyd_, -1, split_rid,
&rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append pending attrs < split_rid
//
// upper layers should make sure this can't fail by limiting the
// maximum commit size
err = lfsr_rbyd_appendattrs(lfs, &rbyd_, rid, -1, split_rid,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// finalize commit
err = lfsr_rbyd_appendcksum(lfs, &rbyd_);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// copy over tags >= split_rid
err = lfsr_rbyd_compact(lfs, &sibling, split_rid, -1,
&rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append pending attrs >= split_rid
//
// upper layers should make sure this can't fail by limiting the
// maximum commit size
err = lfsr_rbyd_appendattrs(lfs, &sibling, rid, split_rid, -1,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// finalize commit
err = lfsr_rbyd_appendcksum(lfs, &sibling);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// did one of our siblings drop to zero? yes this can happen! revert
// to a normal commit in that case
if (rbyd_.weight == 0 || sibling.weight == 0) {
if (rbyd_.weight == 0) {
rbyd_ = sibling;
}
goto finalize;
}
// lookup first name in sibling to use as the split name
//
// note we need to do this after playing out pending attrs in case
// they introduce a new name!
lfsr_tag_t split_tag;
lfsr_data_t split_data;
err = lfsr_rbyd_lookupnext(lfs, &sibling, 0, LFSR_TAG_NAME,
NULL, &split_tag, NULL, &split_data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// prepare commit to parent, tail recursing upwards
LFS_ASSERT(rbyd_.weight > 0);
LFS_ASSERT(sibling.weight > 0);
attr_count = 0;
buf_size = 0;
// new root?
if (!lfsr_rbyd_hastrunk(&parent)) {
attrs__[attr_count++] = LFSR_ATTR(
BRANCH, +rbyd_.weight,
FROMBRANCH(&rbyd_, &buf__[buf_size]));
buf_size += LFSR_BRANCH_DSIZE;
attrs__[attr_count++] = LFSR_ATTR(
BRANCH, +sibling.weight,
FROMBRANCH(&sibling, &buf__[buf_size]));
buf_size += LFSR_BRANCH_DSIZE;
if (lfsr_tag_suptype(split_tag) == LFSR_TAG_NAME) {
attrs__[attr_count++] = LFSR_ATTR(
NAME, 0, DATA(split_data));
}
// split root?
} else {
bid -= pid - (rbyd.weight-1);
attrs__[attr_count++] = LFSR_ATTR(
BRANCH, 0,
FROMBRANCH(&rbyd_, &buf__[buf_size]));
buf_size += LFSR_BRANCH_DSIZE;
if (rbyd_.weight != rbyd.weight) {
attrs__[attr_count++] = LFSR_ATTR(
GROW, -rbyd.weight + rbyd_.weight, NULL());
}
attrs__[attr_count++] = LFSR_ATTR(
BRANCH, +sibling.weight,
FROMBRANCH(&sibling, &buf__[buf_size]));
buf_size += LFSR_BRANCH_DSIZE;
if (lfsr_tag_suptype(split_tag) == LFSR_TAG_NAME) {
attrs__[attr_count++] = LFSR_ATTR(
NAME, 0, DATA(split_data));
}
}
attrs = attrs__;
rbyd = parent;
rid = pid;
continue;
merge:;
// allocate a new rbyd
err = lfsr_rbyd_alloc(lfs, &rbyd_);
if (err) {
return err;
}
// merge the siblings together
err = lfsr_rbyd_appendcompactrbyd(lfs, &rbyd_, -1, -1, &rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
err = lfsr_rbyd_appendcompactrbyd(lfs, &rbyd_, -1, -1, &sibling);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
err = lfsr_rbyd_appendcompaction(lfs, &rbyd_, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append any pending attrs, it's up to upper
// layers to make sure these always fit
err = lfsr_rbyd_appendattrs(lfs, &rbyd_, rid, -1, -1,
attrs, attr_count);
if (err) {
return err;
}
// finalize the commit
err = lfsr_rbyd_appendcksum(lfs, &rbyd_);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// we must have a parent at this point, but is our parent the root
// and is the root degenerate?
LFS_ASSERT(lfsr_rbyd_hastrunk(&parent) != 0);
if (rbyd.weight+sibling.weight == btree->weight) {
// collapse the root, decreasing the height of the tree
*btree = rbyd_;
*attr_count_ = 0;
return 0;
}
// prepare commit to parent, tail recursing upwards
LFS_ASSERT(rbyd_.weight > 0);
attr_count = 0;
buf_size = 0;
bid -= pid - (rbyd.weight-1);
attrs__[attr_count++] = LFSR_ATTR(
RM, -sibling.weight, NULL());
attrs__[attr_count++] = LFSR_ATTR(
BRANCH, 0, FROMBRANCH(&rbyd_, &buf__[buf_size]));
buf_size += LFSR_BRANCH_DSIZE;
if (rbyd_.weight != rbyd.weight) {
attrs__[attr_count++] = LFSR_ATTR(
GROW, -rbyd.weight + rbyd_.weight, NULL());
}
attrs = attrs__;
rbyd = parent;
rid = pid;
continue;
}
}
// this is atomic
static int lfsr_btree_commit(lfs_t *lfs, lfsr_btree_t *btree, lfsr_bid_t bid,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// we need some scratch space for tail-recursive attrs
lfsr_attr_t attrs__[4];
uint8_t buffer[2*LFSR_BRANCH_DSIZE];
// try to commit to the btree
int err = lfsr_btree_commit_(lfs, btree,
&bid, &attrs, &attr_count,
attrs__, buffer);
if (err && err != LFS_ERR_RANGE) {
return err;
}
// needs a new root?
if (err == LFS_ERR_RANGE) {
LFS_ASSERT(attr_count > 0);
lfsr_rbyd_t rbyd;
err = lfsr_rbyd_alloc(lfs, &rbyd);
if (err) {
return err;
}
err = lfsr_rbyd_commit(lfs, &rbyd, bid, attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
*btree = rbyd;
}
LFS_ASSERT(lfsr_rbyd_hastrunk(btree));
return 0;
}
// lookup in a btree by name
static lfs_scmp_t lfsr_btree_namelookup(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_did_t did, const char *name, lfs_size_t name_size,
lfsr_bid_t *bid_,
lfsr_tag_t *tag_, lfsr_bid_t *weight_, lfsr_data_t *data_) {
// an empty tree?
if (btree->weight == 0) {
return LFS_ERR_NOENT;
}
// descend down the btree looking for our name
lfsr_rbyd_t branch = *btree;
lfsr_bid_t bid = 0;
while (true) {
// lookup our name in the rbyd via binary search
lfsr_srid_t rid__;
lfsr_rid_t weight__;
lfs_scmp_t cmp = lfsr_rbyd_namelookup(lfs, &branch,
did, name, name_size,
&rid__, NULL, &weight__, NULL);
if (cmp < 0) {
LFS_ASSERT(cmp != LFS_ERR_NOENT);
return cmp;
}
// the name may not match exactly, but indicates which branch to follow
lfsr_tag_t tag__;
lfsr_data_t data__;
int err = lfsr_rbyd_sublookup(lfs, &branch, rid__, LFSR_TAG_STRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
LFS_ASSERT(err < 0);
return err;
}
// found another branch
if (tag__ == LFSR_TAG_BRANCH) {
// update our bid
bid += rid__ - (weight__-1);
// fetch the next branch
err = lfsr_data_readbranch(lfs, &data__, weight__, &branch);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
// found our rid
} else {
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = bid + rid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
return cmp;
}
}
}
// incremental btree traversal
//
// note this is different from iteration, iteration should use
// lfsr_btree_lookupnext, traversal includes inner btree nodes
typedef struct lfsr_btraversal {
lfsr_bid_t bid;
lfsr_srid_t rid;
lfsr_rbyd_t branch;
} lfsr_btraversal_t;
#define LFSR_BTRAVERSAL() \
((lfsr_btraversal_t){ \
.bid=0, \
.rid=0, \
.branch.trunk=0, \
.branch.weight=0})
static int lfsr_btree_traverse_(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_btraversal_t *btraversal,
lfsr_bid_t *bid_, lfsr_tinfo_t *tinfo_) {
// explicitly traverse the root even if weight=0
if (btraversal->branch.trunk == 0
// unless we don't even have a root yet
&& lfsr_rbyd_trunk(btree) != 0
// or are a shrub
&& !lfsr_rbyd_isshrub(btree)) {
btraversal->rid = btraversal->bid;
btraversal->branch = *btree;
// traverse the root
if (btraversal->rid == 0) {
if (bid_) {
*bid_ = btree->weight-1;
}
if (tinfo_) {
tinfo_->tag = LFSR_TAG_BRANCH;
tinfo_->u.rbyd = btraversal->branch;
}
return 0;
}
}
// need to restart from the root?
if (btraversal->rid >= btraversal->branch.weight) {
btraversal->rid = btraversal->bid;
btraversal->branch = *btree;
}
// descend down the tree
while (true) {
lfsr_srid_t rid__;
lfsr_tag_t tag__;
lfsr_rid_t weight__;
lfsr_data_t data__;
int err = lfsr_rbyd_lookupnext(lfs, &btraversal->branch,
btraversal->rid, 0,
&rid__, &tag__, &weight__, &data__);
if (err) {
return err;
}
if (lfsr_tag_suptype(tag__) == LFSR_TAG_NAME) {
err = lfsr_rbyd_sublookup(lfs, &btraversal->branch,
rid__, LFSR_TAG_STRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// found another branch
if (tag__ == LFSR_TAG_BRANCH) {
// adjust rid with subtree's weight
btraversal->rid -= (rid__ - (weight__-1));
// fetch the next branch
err = lfsr_data_readbranch(lfs, &data__, weight__,
&btraversal->branch);
if (err) {
return err;
}
LFS_ASSERT((lfsr_bid_t)btraversal->branch.weight == weight__);
// return inner btree nodes if this is the first time we've
// seen them
if (btraversal->rid == 0) {
if (bid_) {
*bid_ = btraversal->bid + (rid__ - btraversal->rid);
}
if (tinfo_) {
tinfo_->tag = LFSR_TAG_BRANCH;
tinfo_->u.rbyd = btraversal->branch;
}
return 0;
}
// found our bid
} else {
// move on to the next rid
//
// note this effectively traverses a full leaf without redoing
// the btree walk
lfsr_bid_t bid__ = btraversal->bid + (rid__ - btraversal->rid);
btraversal->bid = bid__ + 1;
btraversal->rid = rid__ + 1;
if (bid_) {
*bid_ = bid__;
}
if (tinfo_) {
tinfo_->tag = tag__;
tinfo_->u.data = data__;
}
return 0;
}
}
}
static int lfsr_btree_traverse(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_btraversal_t *btraversal,
lfsr_bid_t *bid_, lfsr_tinfo_t *tinfo_) {
return lfsr_btree_traverse_(lfs, btree, btraversal,
bid_, tinfo_);
}
/// shrub/sprout things ///
// needed in shrub/sprout/mdir/etc
static inline bool lfsr_bshrub_isbnull(const lfsr_bshrub_t *bshrub);
static inline bool lfsr_bshrub_isbsprout(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub);
static inline bool lfsr_bshrub_isbptr(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub);
static inline bool lfsr_bshrub_isbshrub(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub);
static inline bool lfsr_bshrub_isbtree(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub);
static inline bool lfsr_bshrub_isbnullorbsproutorbptr(
const lfsr_bshrub_t *bshrub);
static inline bool lfsr_bshrub_isbshruborbtree(
const lfsr_bshrub_t *bshrub);
// sprout things
static inline int lfsr_sprout_cmp(
const lfsr_data_t *a,
const lfsr_data_t *b) {
// big assumption for sprouts, we convert straight to bshrubs,
// and never leave sliced sprouts in our files, so we don't need
// to compare the size
LFS_ASSERT(a->u.disk.block != b->u.disk.block
|| a->u.disk.off != b->u.disk.off
|| lfsr_data_size(a) == lfsr_data_size(b));
if (a->u.disk.block != b->u.disk.block) {
return a->u.disk.block - b->u.disk.block;
} else {
return a->u.disk.off - b->u.disk.off;
}
}
// these are used in mdir compaction
static lfs_ssize_t lfsr_sprout_estimate(lfs_t *lfs,
const lfsr_data_t *sprout) {
// only include the last reference
const lfsr_data_t *last = NULL;
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& lfsr_bshrub_isbsprout(&file_->m.mdir, &file_->bshrub)
&& lfsr_sprout_cmp(&file_->bshrub.u.bsprout, sprout) == 0) {
last = &file_->bshrub.u.bsprout;
}
}
if (last && sprout != last) {
return 0;
}
return LFSR_TAG_DSIZE + lfsr_data_size(sprout);
}
static int lfsr_sprout_compact(lfs_t *lfs, const lfsr_rbyd_t *rbyd_,
lfsr_data_t *sprout_, const lfsr_data_t *sprout) {
// this gets a bit weird, since upper layers need to do the actual
// compaction, we just update internal state here
// this is a bit tricky since we don't know the tag size,
// but we have just enough info
lfsr_data_t sprout__ = LFSR_DATA_DISK(
rbyd_->blocks[0],
rbyd_->eoff - lfsr_data_size(sprout),
lfsr_data_size(sprout));
// stage any opened inlined files with their new location so we
// can update these later if our commit is a success
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& lfsr_bshrub_isbsprout(&file_->m.mdir, &file_->bshrub)
&& lfsr_sprout_cmp(
&file_->bshrub.u.bsprout,
sprout) == 0) {
file_->bshrub_.u.bsprout = sprout__;
}
}
*sprout_ = sprout__;
return 0;
}
// shrub things
static inline lfs_size_t lfsr_shrub_trunk(const lfsr_shrub_t *shrub) {
return shrub->trunk & ~LFSR_RBYD_SHRUB;
}
static inline bool lfsr_shrub_hastrunk(const lfsr_shrub_t *shrub) {
return lfsr_shrub_trunk(shrub) != 0;
}
static inline int lfsr_shrub_cmp(
const lfsr_shrub_t *a,
const lfsr_shrub_t *b) {
return lfsr_rbyd_cmp(a, b);
}
// shrub on-disk encoding
// 2 leb128s => 10 bytes (worst case)
#define LFSR_SHRUB_DSIZE (5+5)
#define LFSR_DATA_FROMSHRUB(_rbyd, _buffer) \
lfsr_data_fromtrunk(_rbyd, _buffer)
static lfsr_data_t lfsr_data_fromshrub(const lfsr_shrub_t *shrub,
uint8_t buffer[static LFSR_SHRUB_DSIZE]) {
// shrub trunks should never be null
LFS_ASSERT(lfsr_shrub_trunk(shrub) != 0);
lfs_ssize_t d = 0;
// just write the trunk and weight, the rest of the rbyd is contextual
lfs_ssize_t d_ = lfs_toleb128(shrub->weight, &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
d_ = lfs_toleb128(lfsr_shrub_trunk(shrub), &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
return LFSR_DATA_BUF(buffer, d);
}
static int lfsr_data_readshrub(lfs_t *lfs, lfsr_data_t *data,
const lfsr_mdir_t *mdir,
lfsr_shrub_t *shrub) {
// copy the mdir block
shrub->blocks[0] = mdir->rbyd.blocks[0];
// force estimate recalculation if we write to this shrub
shrub->eoff = -1;
int err = lfsr_data_readleb128(lfs, data, &shrub->weight);
if (err) {
return err;
}
err = lfsr_data_readleb128(lfs, data, &shrub->trunk);
if (err) {
return err;
}
// shrub trunks should never be null
LFS_ASSERT(lfsr_shrub_hastrunk(shrub));
// set the shrub bit in our trunk
shrub->trunk |= LFSR_RBYD_SHRUB;
return 0;
}
// these are used in mdir commit/compaction
static lfs_ssize_t lfsr_shrub_estimate(lfs_t *lfs,
const lfsr_shrub_t *shrub) {
// only include the last reference
const lfsr_shrub_t *last = NULL;
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& lfsr_bshrub_isbshrub(&file_->m.mdir, &file_->bshrub)
&& lfsr_shrub_cmp(&file_->bshrub.u.bshrub, shrub) == 0) {
last = &file_->bshrub.u.bshrub;
}
}
if (last && shrub != last) {
return 0;
}
return lfsr_rbyd_estimate(lfs, shrub, -1, -1,
NULL);
}
static int lfsr_shrub_compact(lfs_t *lfs, lfsr_rbyd_t *rbyd_,
lfsr_shrub_t *shrub_, const lfsr_shrub_t *shrub) {
// save our current trunk/weight
lfs_ssize_t trunk = rbyd_->trunk;
lfsr_srid_t weight = rbyd_->weight;
// compact our bshrub
int err = lfsr_rbyd_appendshrub(lfs, rbyd_, shrub);
if (err) {
return err;
}
// stage any opened shrubs with their new location so we can
// update these later if our commit is a success
//
// this should include our current bshrub
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& lfsr_bshrub_isbshrub(&file_->m.mdir, &file_->bshrub)
&& lfsr_shrub_cmp(&file_->bshrub.u.bshrub, shrub) == 0) {
file_->bshrub_.u.bshrub.blocks[0] = rbyd_->blocks[0];
file_->bshrub_.u.bshrub.trunk = rbyd_->trunk;
file_->bshrub_.u.bshrub.weight = rbyd_->weight;
}
}
// revert rbyd trunk/weight
shrub_->blocks[0] = rbyd_->blocks[0];
shrub_->trunk = rbyd_->trunk;
shrub_->weight = rbyd_->weight;
rbyd_->trunk = trunk;
rbyd_->weight = weight;
return 0;
}
// this is needed to sneak shrub commits into mdir commits
typedef struct lfsr_shrubcommit_t {
lfsr_shrub_t *shrub;
lfsr_srid_t rid;
const lfsr_attr_t *attrs;
lfs_size_t attr_count;
} lfsr_shrubcommit_t;
static int lfsr_shrub_commit(lfs_t *lfs, lfsr_rbyd_t *rbyd_,
lfsr_shrub_t *shrub, lfsr_srid_t rid,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// swap out our trunk/weight temporarily, note we're
// operating on a copy so if this fails we shouldn't mess
// things up too much
//
// it is important that these rbyds share eoff/cksum/etc
lfs_ssize_t trunk = rbyd_->trunk;
lfsr_srid_t weight = rbyd_->weight;
rbyd_->trunk = shrub->trunk;
rbyd_->weight = shrub->weight;
// append any bshrub attributes
int err = lfsr_rbyd_appendattrs(lfs, rbyd_, rid, -1, -1,
attrs, attr_count);
if (err) {
return err;
}
// restore mdir to the main trunk/weight
shrub->trunk = rbyd_->trunk;
shrub->weight = rbyd_->weight;
rbyd_->trunk = trunk;
rbyd_->weight = weight;
return 0;
}
/// Metadata pair stuff ///
// metadata-id things
static inline lfsr_mid_t lfsr_mweight(lfs_t *lfs) {
return 1 << lfs->mbits;
}
#define LFSR_MID(_lfs, _bid, _rid) \
(((_bid) & ~((1 << (_lfs)->mbits)-1)) + (_rid) + 1)
static inline lfsr_sbid_t lfsr_mid_bid(lfs_t *lfs, lfsr_smid_t mid) {
return mid | ((1 << lfs->mbits) - 1);
}
static inline lfsr_srid_t lfsr_mid_rid(lfs_t *lfs, lfsr_smid_t mid) {
// subtle mapping here
// - mid=-1 => rid=-1
// - mid=0 => rid=-1
// - mid=1 => rid=0
// - mid=2 => rid=1
// - ...
return (mid >> (8*sizeof(lfsr_smid_t)-1))
| ((mid & ((1 << lfs->mbits) - 1)) - 1);
}
// metadata-pointer things
// the mroot anchor, mdir 0x{0,1} is the entry point into the filesystem
#define LFSR_MPTR_MROOTANCHOR() ((const lfsr_mptr_t){{0, 1}})
static inline int lfsr_mptr_cmp(
const lfsr_mptr_t *a,
const lfsr_mptr_t *b) {
// note these can be in either order
if (lfs_max32(a->blocks[0], a->blocks[1])
!= lfs_max32(b->blocks[0], b->blocks[1])) {
return lfs_max32(a->blocks[0], a->blocks[1])
- lfs_max32(b->blocks[0], b->blocks[1]);
} else {
return lfs_min32(a->blocks[0], a->blocks[1])
- lfs_min32(b->blocks[0], b->blocks[1]);
}
}
static inline bool lfsr_mptr_ismrootanchor(const lfsr_mptr_t *mptr) {
// mrootanchor is always at 0x{0,1}
// just check that the first block is in mroot anchor range
return mptr->blocks[0] <= 1;
}
// 2 leb128 => 10 bytes (worst case)
#define LFSR_MPTR_DSIZE (5+5)
#define LFSR_DATA_FROMMPTR(_mptr, _buffer) \
lfsr_data_frommptr(_mptr, _buffer)
static lfsr_data_t lfsr_data_frommptr(const lfsr_mptr_t *mptr,
uint8_t buffer[static LFSR_MPTR_DSIZE]) {
lfs_ssize_t d = 0;
for (int i = 0; i < 2; i++) {
lfs_ssize_t d_ = lfs_toleb128(mptr->blocks[i], &buffer[d], 5);
LFS_ASSERT(d_ >= 0);
d += d_;
}
return LFSR_DATA_BUF(buffer, d);
}
static int lfsr_data_readmptr(lfs_t *lfs, lfsr_data_t *data,
lfsr_mptr_t *mptr) {
for (int i = 0; i < 2; i++) {
int err = lfsr_data_readleb128(lfs, data, (int32_t*)&mptr->blocks[i]);
if (err) {
return err;
}
}
return 0;
}
// mdir convenience functions
static inline const lfsr_mptr_t *lfsr_mdir_mptr(const lfsr_mdir_t *mdir) {
return (const lfsr_mptr_t*)mdir->rbyd.blocks;
}
static inline int lfsr_mdir_cmp(const lfsr_mdir_t *a, const lfsr_mdir_t *b) {
return lfsr_mptr_cmp(lfsr_mdir_mptr(a), lfsr_mdir_mptr(b));
}
static inline bool lfsr_mdir_ismrootanchor(const lfsr_mdir_t *mdir) {
return lfsr_mptr_ismrootanchor(lfsr_mdir_mptr(mdir));
}
// mdir operations
static int lfsr_mdir_fetch(lfs_t *lfs, lfsr_mdir_t *mdir,
lfsr_smid_t mid, const lfsr_mptr_t *mptr) {
// create a copy of blocks, this is so we can swap the blocks
// to keep track of the current revision, this also prevents issues
// if blocks points to the blocks in the mdir
lfs_block_t blocks_[2] = {mptr->blocks[0], mptr->blocks[1]};
// read both revision counts, try to figure out which block
// has the most recent revision
uint32_t revs[2] = {0, 0};
for (int i = 0; i < 2; i++) {
int err = lfsr_bd_read(lfs, blocks_[0], 0, 0,
&revs[0], sizeof(uint32_t));
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
revs[i] = lfs_fromle32_(&revs[i]);
if (i == 0
|| err == LFS_ERR_CORRUPT
|| lfs_scmp(revs[1], revs[0]) > 0) {
lfs_swap32(&blocks_[0], &blocks_[1]);
lfs_swap32(&revs[0], &revs[1]);
}
}
// try to fetch rbyds in the order of most recent to least recent
for (int i = 0; i < 2; i++) {
int err = lfsr_rbyd_fetch(lfs, &mdir->rbyd, blocks_[0], 0);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (err != LFS_ERR_CORRUPT) {
mdir->mid = mid;
// keep track of other block for compactions
mdir->rbyd.blocks[1] = blocks_[1];
return 0;
}
lfs_swap32(&blocks_[0], &blocks_[1]);
lfs_swap32(&revs[0], &revs[1]);
}
// could not find a non-corrupt rbyd
return LFS_ERR_CORRUPT;
}
static int lfsr_mdir_lookupnext(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_smid_t mid, lfsr_tag_t tag,
lfsr_tag_t *tag_, lfsr_data_t *data_) {
lfsr_srid_t rid__;
lfsr_tag_t tag__;
int err = lfsr_rbyd_lookupnext(lfs, &mdir->rbyd,
lfsr_mid_rid(lfs, mid), tag,
&rid__, &tag__, NULL, data_);
if (err) {
return err;
}
// this is very similar to lfsr_rbyd_lookupnext, but we error if
// lookupnext would change mids
if (rid__ != lfsr_mid_rid(lfs, mid)) {
return LFS_ERR_NOENT;
}
// intercept pending grms here and pretend they're orphaned files
//
// fortunately pending grms/orphaned files have roughly the same
// semantics, and it's easier to manage the implied mid gap in
// higher-levels
if (lfsr_tag_suptype(tag__) == LFSR_TAG_NAME
&& lfsr_grm_isrm(&lfs->grm, mid)) {
tag__ = LFSR_TAG_ORPHAN;
}
if (tag_) {
*tag_ = tag__;
}
return 0;
}
static int lfsr_mdir_lookup(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_smid_t mid, lfsr_tag_t tag,
lfsr_data_t *data_) {
lfsr_tag_t tag_;
int err = lfsr_mdir_lookupnext(lfs, mdir, mid, tag,
&tag_, data_);
if (err) {
return err;
}
// lookup finds the next-smallest tag, all we need to do is fail if it
// picks up the wrong tag
if (tag_ != tag) {
return LFS_ERR_NOENT;
}
return 0;
}
static int lfsr_mdir_sublookup(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_smid_t mid, lfsr_tag_t tag,
lfsr_tag_t *tag_, lfsr_data_t *data_) {
// looking up a wide tag with subtype is probably a mistake
LFS_ASSERT(lfsr_tag_subtype(tag) == 0);
lfsr_tag_t tag__;
int err = lfsr_mdir_lookupnext(lfs, mdir, mid, tag,
&tag__, data_);
if (err) {
return err;
}
// the difference between lookup and sublookup is we accept any
// subtype of the requested tag
if (lfsr_tag_suptype(tag__) != tag) {
return LFS_ERR_NOENT;
}
if (tag_) {
*tag_ = tag__;
}
return 0;
}
static int lfsr_mdir_suplookup(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_smid_t mid,
lfsr_tag_t *tag_, lfsr_data_t *data_) {
lfsr_tag_t tag__;
int err = lfsr_mdir_lookupnext(lfs, mdir, mid, 0,
&tag__, data_);
if (err) {
return err;
}
// the difference between lookup and sublookup is we accept any tag
if (tag_) {
*tag_ = tag__;
}
return 0;
}
// track opened mdirs to keep state in-sync
static bool lfsr_isopened(lfs_t *lfs, const lfsr_opened_t *opened) {
for (lfsr_opened_t *p = lfs->opened; p; p = p->next) {
if (p == opened) {
return true;
}
}
return false;
}
static void lfsr_addopened(lfs_t *lfs, lfsr_opened_t *opened) {
LFS_ASSERT(!lfsr_isopened(lfs, opened));
opened->next = lfs->opened;
lfs->opened = opened;
}
static void lfsr_removeopened(lfs_t *lfs, lfsr_opened_t *opened) {
LFS_ASSERT(lfsr_isopened(lfs, opened));
for (lfsr_opened_t **p = &lfs->opened; *p; p = &(*p)->next) {
if (*p == opened) {
*p = (*p)->next;
break;
}
}
}
static bool lfsr_mid_isopened(lfs_t *lfs, lfsr_smid_t mid) {
for (lfsr_opened_t *p = lfs->opened; p; p = p->next) {
// we really only care about regular open files here, all
// others are either transient (dirs) or fake (orphans)
if (p->type == LFS_TYPE_REG && p->mdir.mid == mid) {
return true;
}
}
return false;
}
/// Metadata-tree things ///
// the mtree is the core tree of mdirs in littlefs
#define LFSR_MTREE_ISMPTR 0x80000000
#define LFSR_MTREE_NULL() ((lfsr_mtree_t){ \
.u.weight=(LFSR_MTREE_ISMPTR | 0)})
#define LFSR_MTREE_MPTR(_mptr, _weight) ((lfsr_mtree_t){ \
.u.mptr.weight=(LFSR_MTREE_ISMPTR | (_weight)), \
.u.mptr.mptr=_mptr})
static inline bool lfsr_mtree_isnull(lfs_t *lfs) {
return (lfsr_mid_t)lfs->mtree.u.weight == (LFSR_MTREE_ISMPTR | 0);
}
static inline bool lfsr_mtree_ismptr(lfs_t *lfs) {
return lfs->mtree.u.weight & LFSR_MTREE_ISMPTR;
}
static inline bool lfsr_mtree_isbtree(lfs_t *lfs) {
return !(lfs->mtree.u.weight & LFSR_MTREE_ISMPTR);
}
static inline lfsr_mid_t lfsr_mtree_weight(lfs_t *lfs) {
return lfs->mtree.u.weight & ~LFSR_MTREE_ISMPTR;
}
static int lfsr_mtree_lookup(lfs_t *lfs, lfsr_smid_t mid,
lfsr_mdir_t *mdir_) {
// looking up mroot?
if (lfsr_mtree_isnull(lfs)) {
LFS_ASSERT(mid >= 0);
LFS_ASSERT(mid < (lfsr_smid_t)lfsr_mweight(lfs));
mdir_->mid = mid;
mdir_->rbyd = lfs->mroot.rbyd;
return 0;
// looking up direct mdir?
} else if (lfsr_mtree_ismptr(lfs)) {
LFS_ASSERT(mid >= 0);
LFS_ASSERT(mid < (lfsr_smid_t)lfsr_mweight(lfs));
// fetch mdir
return lfsr_mdir_fetch(lfs, mdir_, mid, &lfs->mtree.u.mptr.mptr);
// look up mdir in actual mtree
} else {
LFS_ASSERT(mid >= 0);
LFS_ASSERT(mid < (lfsr_smid_t)lfsr_mtree_weight(lfs));
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_btree_lookupnext(lfs, &lfs->mtree.u.btree,
mid,
&bid, &tag, NULL, &data);
if (err) {
return err;
}
LFS_ASSERT((lfsr_sbid_t)bid == lfsr_mid_bid(lfs, mid));
LFS_ASSERT(tag == LFSR_TAG_MDIR);
// decode mdir
lfsr_mptr_t mptr;
err = lfsr_data_readmptr(lfs, &data, &mptr);
if (err) {
return err;
}
// fetch mdir
return lfsr_mdir_fetch(lfs, mdir_, mid, &mptr);
}
}
static int lfsr_mtree_seek(lfs_t *lfs, lfsr_mdir_t *mdir, lfs_off_t off) {
// upper layers should handle removed mdirs
LFS_ASSERT(mdir->mid >= 0);
while (true) {
// calculate new mid, be careful to avoid rid overflow
lfsr_bid_t bid = lfsr_mid_bid(lfs, mdir->mid);
lfsr_srid_t rid = lfsr_mid_rid(lfs, mdir->mid) + off;
// lookup mdirs until we find our rid, we need to do this because
// we don't know how many rids are in each mdir until we fetch
while (rid >= mdir->rbyd.weight) {
// end of mtree?
if (bid+lfsr_mweight(lfs) >= lfsr_mtree_weight(lfs)) {
// if we hit the end of the mtree, park the mdir so all future
// seeks return noent
mdir->mid = bid + lfsr_mweight(lfs);
return LFS_ERR_NOENT;
}
bid += lfsr_mweight(lfs);
rid -= mdir->rbyd.weight;
int err = lfsr_mtree_lookup(lfs, bid, mdir);
if (err) {
return err;
}
}
mdir->mid = LFSR_MID(lfs, bid, rid);
return 0;
}
}
/// Mdir commit logic ///
// this is the gooey atomic center of littlefs
//
// any mutation must go through lfsr_mdir_commit to persist on disk
//
// this makes lfsr_mdir_commit also responsible for propagating changes
// up through the mtree/mroot chain, and through any internal structures,
// making lfsr_mdir_commit quite involved and a bit of a mess.
// some mdir-related gstate things we need
static void lfsr_fs_flushgdelta(lfs_t *lfs) {
memset(lfs->grm_d, 0, LFSR_GRM_DSIZE);
}
static int lfsr_fs_consumegdelta(lfs_t *lfs, const lfsr_mdir_t *mdir) {
lfsr_data_t data;
int err = lfsr_mdir_lookup(lfs, mdir, -1, LFSR_TAG_GRMDELTA,
&data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
err = lfsr_grm_xor(lfs, lfs->grm_d, data);
if (err) {
return err;
}
}
return 0;
}
// low-level mdir operations needed by lfsr_mdir_commit
static int lfsr_mdir_alloc__(lfs_t *lfs, lfsr_mdir_t *mdir, lfsr_smid_t mid) {
// assign the mid
mdir->mid = mid;
// allocate two blocks
for (int i = 0; i < 2; i++) {
int err = lfs_alloc(lfs, &mdir->rbyd.blocks[i]);
if (err) {
return err;
}
}
mdir->rbyd.weight = 0;
mdir->rbyd.trunk = 0;
mdir->rbyd.eoff = 0;
mdir->rbyd.cksum = 0;
// read the new revision count
//
// we use whatever is on-disk to avoid needing to rewrite the
// redund block
uint32_t rev;
int err = lfsr_bd_read(lfs, mdir->rbyd.blocks[1], 0, sizeof(uint32_t),
&rev, sizeof(uint32_t));
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// note we allow corrupt errors here, as long as they are consistent
rev = (err != LFS_ERR_CORRUPT) ? lfs_fromle32_(&rev) : 0;
// align revision count in new mdirs to our block_cycles, this makes
// sure we don't immediately try to relocate the mdir
if (lfs->cfg->block_cycles > 0) {
rev = lfs_alignup(rev+1, lfs->cfg->block_cycles)-1;
}
// erase, preparing for compact
err = lfsr_bd_erase(lfs, mdir->rbyd.blocks[0]);
if (err) {
return err;
}
// increment our revision count and write it to our rbyd
// TODO rev things
err = lfsr_rbyd_appendrev(lfs, &mdir->rbyd, rev + 1);
if (err) {
return err;
}
return 0;
}
static int lfsr_mdir_swap__(lfs_t *lfs, lfsr_mdir_t *mdir_,
const lfsr_mdir_t *mdir, bool force) {
// assign the mid
mdir_->mid = mdir->mid;
// first thing we need to do is read our current revision count
uint32_t rev;
int err = lfsr_bd_read(lfs, mdir->rbyd.blocks[0], 0, sizeof(uint32_t),
&rev, sizeof(uint32_t));
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// note we allow corrupt errors here, as long as they are consistent
rev = (err != LFS_ERR_CORRUPT) ? lfs_fromle32_(&rev) : 0;
// decide if we need to relocate
if (!force
&& lfs->cfg->block_cycles > 0
// TODO rev things
&& (rev + 1) % lfs->cfg->block_cycles == 0) {
// alloc a new mdir
return lfsr_mdir_alloc__(lfs, mdir_, mdir->mid);
}
// swap our blocks
mdir_->rbyd.blocks[0] = mdir->rbyd.blocks[1];
mdir_->rbyd.blocks[1] = mdir->rbyd.blocks[0];
mdir_->rbyd.weight = 0;
mdir_->rbyd.trunk = 0;
mdir_->rbyd.eoff = 0;
mdir_->rbyd.cksum = 0;
// erase, preparing for compact
err = lfsr_bd_erase(lfs, mdir_->rbyd.blocks[0]);
if (err) {
return err;
}
// increment our revision count and write it to our rbyd
// TODO rev things
err = lfsr_rbyd_appendrev(lfs, &mdir_->rbyd, rev + 1);
if (err) {
return err;
}
return 0;
}
// low-level mdir commit, does not handle mtree/mlist/compaction/etc
static int lfsr_mdir_commit__(lfs_t *lfs, lfsr_mdir_t *mdir,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
lfsr_smid_t mid, const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// try to append a commit
lfsr_rbyd_t rbyd_ = mdir->rbyd;
lfsr_srid_t rid = lfsr_mid_rid(lfs, mid);
// mark as erased in case of failure
mdir->rbyd.eoff = -1;
for (lfs_size_t i = 0; i < attr_count; i++) {
// don't write tags outside of the requested range
lfsr_srid_t rid_ = rid + (
(!lfsr_tag_isgrow(attrs[i].tag) && attrs[i].delta > 0)
? 1 : 0);
if (rid_ >= start_rid
// note the use of rid+1 and unsigned comparison here to
// treat end_rid=-1 as "unbounded" in such a way that rid=-1
// is still included
&& (lfs_size_t)(rid_ + 1) <= (lfs_size_t)end_rid) {
// ignore any gstate tags here, these need to be handled
// specially by upper-layers
if (attrs[i].tag == LFSR_TAG_GRM) {
// do nothing
// move tags copy over any tags associated with the source's rid
// TODO can this be deduplicated with lfsr_mdir_compact__ more?
// it _really_ wants to be deduplicated
} else if (attrs[i].tag == LFSR_TAG_MOVE) {
// weighted moves are not supported
LFS_ASSERT(attrs[i].delta == 0);
const lfsr_mdir_t *mdir__
= (const lfsr_mdir_t*)attrs[i].data.u.buf.buffer;
// skip the name tag, this is always replaced by upper layers
lfsr_tag_t tag = LFSR_TAG_STRUCT-1;
while (true) {
lfsr_data_t data;
int err = lfsr_mdir_lookupnext(lfs, mdir__,
mdir__->mid, tag+1,
&tag, &data);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
// found an inlined sprout? we can just copy this like
// normal but we need to update any opened inlined files
if (tag == LFSR_TAG_DATA) {
err = lfsr_rbyd_appendattr(lfs, &rbyd_,
rid - lfs_smax32(start_rid, 0),
tag, 0, data);
if (err) {
return err;
}
err = lfsr_sprout_compact(lfs, &rbyd_, &data,
&data);
if (err) {
return err;
}
// found an inlined shrub? we need to compact the shrub
// as well to bring it along with us
} else if (tag == LFSR_TAG_BSHRUB) {
lfsr_shrub_t shrub;
err = lfsr_data_readshrub(lfs, &data, mdir__,
&shrub);
if (err) {
return err;
}
// compact our bshrub
err = lfsr_shrub_compact(lfs, &rbyd_, &shrub,
&shrub);
if (err) {
return err;
}
// write our new shrub tag
uint8_t shrub_buf[LFSR_SHRUB_DSIZE];
err = lfsr_rbyd_appendattr(lfs, &rbyd_,
rid - lfs_smax32(start_rid, 0),
LFSR_TAG_BSHRUB, 0, lfsr_data_fromshrub(
&shrub, shrub_buf));
if (err) {
return err;
}
// append the attr
} else {
err = lfsr_rbyd_appendattr(lfs, &rbyd_,
rid - lfs_smax32(start_rid, 0),
tag, 0, data);
if (err) {
return err;
}
}
}
// we're not quite done! we also need to bring over any
// unsynced files
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
lfsr_file_t *file = (lfsr_file_t*)opened;
// belongs to our mid?
if (file->m.type != LFS_TYPE_REG
|| file->m.mdir.mid != mdir__->mid) {
continue;
}
// inlined sprout?
if (lfsr_bshrub_isbsprout(&file->m.mdir, &file->bshrub)
// only compact once, first compact should stage
// the new block
&& file->bshrub_.u.bsprout.u.disk.block
!= rbyd_.blocks[0]) {
int err = lfsr_rbyd_appendcompactattr(lfs, &rbyd_,
LFSR_TAG_SHRUB(DATA), 0,
file->bshrub.u.bsprout);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
err = lfsr_sprout_compact(lfs, &rbyd_,
&file->bshrub_.u.bsprout,
&file->bshrub.u.bsprout);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// inlined shrub?
} else if (lfsr_bshrub_isbshrub(
&file->m.mdir, &file->bshrub)
// only compact once, first compact should stage
// the new block
&& file->bshrub.u.bshrub.blocks[0]
!= rbyd_.blocks[0]) {
int err = lfsr_shrub_compact(lfs, &rbyd_,
&file->bshrub_.u.bshrub,
&file->bshrub.u.bshrub);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
}
// shrub tags append a set of attributes to an unrelated trunk
// in our rbyd
} else if (attrs[i].tag == LFSR_TAG_SHRUBALLOC
|| attrs[i].tag == LFSR_TAG_SHRUBCOMMIT) {
const lfsr_shrubcommit_t *bshrubcommit
= (const lfsr_shrubcommit_t*)attrs[i].data.u.buf.buffer;
// SHRUBALLOC is roughly the same as SHRUBCOMMIT but also
// resets the shrub, we need to do this here so bshrub root
// extensions are atomic
if (attrs[i].tag == LFSR_TAG_SHRUBALLOC) {
bshrubcommit->shrub->blocks[0] = rbyd_.blocks[0];
bshrubcommit->shrub->trunk = LFSR_RBYD_SHRUB | 0;
bshrubcommit->shrub->weight = 0;
}
int err = lfsr_shrub_commit(lfs, &rbyd_,
bshrubcommit->shrub,
bshrubcommit->rid,
bshrubcommit->attrs,
bshrubcommit->attr_count);
if (err) {
return err;
}
// lazily encode inlined trunks in case they change underneath
// us due to mdir compactions
//
// TODO should we preserve mode for all of these?
// TODO should we do the same for sprouts?
} else if (lfsr_tag_key(attrs[i].tag) == LFSR_TAG_SHRUBTRUNK) {
lfsr_shrub_t *shrub
= (lfsr_shrub_t*)attrs[i].data.u.buf.buffer;
uint8_t shrub_buf[LFSR_SHRUB_DSIZE];
int err = lfsr_rbyd_appendattr(lfs, &rbyd_,
rid - lfs_smax32(start_rid, 0),
lfsr_tag_mode(attrs[i].tag) | LFSR_TAG_BSHRUB,
attrs[i].delta,
lfsr_data_fromshrub(
// note we use the staged trunk here
shrub, shrub_buf));
if (err) {
return err;
}
// write out normal tags normally
} else {
LFS_ASSERT(!lfsr_tag_isinternal(attrs[i].tag));
int err = lfsr_rbyd_appendattr(lfs, &rbyd_,
rid - lfs_smax32(start_rid, 0),
attrs[i].tag, attrs[i].delta, attrs[i].data);
if (err) {
return err;
}
}
}
// we need to make sure we keep start_rid/end_rid updated with
// weight changes
if (rid_ < start_rid) {
start_rid += attrs[i].delta;
}
if (rid_ < end_rid) {
end_rid += attrs[i].delta;
}
// adjust rid
rid += attrs[i].delta;
}
// abort the commit if our weight dropped to zero!
//
// If we finish the commit it becomes immediately visible, but we really
// need to atomically remove this mdir from the mtree. Leave the actual
// remove up to upper layers.
if (rbyd_.weight == 0
// unless we are an mroot
&& !(mdir->mid == -1 || lfsr_mdir_cmp(mdir, &lfs->mroot) == 0)) {
// mark weight as zero, but note! we can no longer read from this mdir
// as our pcache may be clobbered
mdir->rbyd.weight = 0;
return LFS_ERR_NOENT;
}
// append any gstate?
if (start_rid == -1) {
int err = lfsr_rbyd_appendgdelta(lfs, &rbyd_);
if (err) {
return err;
}
}
// finalize commit
int err = lfsr_rbyd_appendcksum(lfs, &rbyd_);
if (err) {
return err;
}
// success? flush gstate?
if (start_rid == -1) {
lfsr_fs_flushgdelta(lfs);
}
mdir->rbyd = rbyd_;
return 0;
}
// TODO do we need to include commit overhead here?
static lfs_ssize_t lfsr_mdir_estimate__(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
lfsr_srid_t *split_rid_) {
// yet another function that is just begging to be deduplicated, but we
// can't because it would be recursive
//
// this is basically the same as lfsr_rbyd_estimate, except we assume all
// rids have weight 1 and have extra handling for opened files, shrubs, etc
// calculate dsize by starting from the outside ids and working inwards,
// this naturally gives us a split rid
lfsr_srid_t rid = start_rid;
lfsr_srid_t other_rid = lfs_min32(mdir->rbyd.weight, end_rid);
lfs_size_t dsize = 0;
lfs_size_t other_dsize = 0;
lfs_size_t mdir_dsize = 0;
while (rid != other_rid) {
if (dsize > other_dsize
// bias so lower dsize >= upper dsize
|| (dsize == other_dsize && rid > other_rid)) {
lfs_sswap32(&rid, &other_rid);
lfs_swap32(&dsize, &other_dsize);
}
if (rid > other_rid) {
rid -= 1;
}
lfsr_tag_t tag = 0;
lfs_size_t dsize_ = 0;
while (true) {
lfsr_srid_t rid_;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, &mdir->rbyd,
rid, tag+1,
&rid_, &tag, NULL, &data);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
LFS_ASSERT(err < 0);
return err;
}
if (rid_ != rid) {
break;
}
// special handling for sprouts, just to avoid duplicate cost
if (tag == LFSR_TAG_DATA) {
lfs_ssize_t dsize__ = lfsr_sprout_estimate(lfs, &data);
if (dsize__ < 0) {
return dsize__;
}
dsize_ += LFSR_ATTR_ESTIMATE + dsize__;
// special handling for shrub trunks, we need to include the
// compacted cost of the shrub in our estimate
//
// this is what would make lfsr_rbyd_estimate recursive, and
// why we need a second function...
//
} else if (tag == LFSR_TAG_BSHRUB) {
// include the cost of this trunk
dsize_ += LFSR_SHRUB_DSIZE;
lfsr_shrub_t shrub;
err = lfsr_data_readshrub(lfs, &data, mdir, &shrub);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
lfs_ssize_t dsize__ = lfsr_shrub_estimate(lfs, &shrub);
if (dsize__ < 0) {
return dsize__;
}
dsize_ += LFSR_ATTR_ESTIMATE + dsize__;
} else {
// include the cost of this tag
dsize_ += LFSR_ATTR_ESTIMATE + lfsr_data_size(&data);
}
}
// include any opened+unsynced inlined files
//
// this is O(n^2), but littlefs is unlikely to have many open
// files, I suppose if this becomes a problem we could sort
// opened files by mid
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
lfsr_file_t *file = (lfsr_file_t*)opened;
// belongs to our mdir + rid?
if (file->m.type != LFS_TYPE_REG
|| lfsr_mdir_cmp(&file->m.mdir, mdir) != 0
|| lfsr_mid_rid(lfs, file->m.mdir.mid) != rid) {
continue;
}
// inlined sprout?
if (lfsr_bshrub_isbsprout(&file->m.mdir, &file->bshrub)) {
lfs_ssize_t dsize__ = lfsr_sprout_estimate(lfs,
&file->bshrub.u.bsprout);
if (dsize__ < 0) {
return dsize__;
}
dsize_ += dsize__;
// inlined shrub?
} else if (lfsr_bshrub_isbshrub(&file->m.mdir, &file->bshrub)) {
lfs_ssize_t dsize__ = lfsr_shrub_estimate(lfs,
&file->bshrub.u.bshrub);
if (dsize__ < 0) {
return dsize__;
}
dsize_ += dsize__;
}
}
if (rid == -1) {
mdir_dsize += dsize_;
} else {
dsize += dsize_;
}
if (rid < other_rid) {
rid += 1;
}
}
if (split_rid_) {
*split_rid_ = rid;
}
return mdir_dsize + dsize + other_dsize;
}
static int lfsr_mdir_compact__(lfs_t *lfs, lfsr_mdir_t *mdir_,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
const lfsr_mdir_t *mdir) {
// this is basically the same as lfsr_rbyd_compact, but with special
// handling for inlined trees.
//
// it's really tempting to deduplicate this via recursion! but we
// can't do that here
//
// TODO this true?
// note that any inlined updates here depend on the pre-commit state
// (btree), not the staged state (btree_), this is important,
// we can't trust btree_ after a failed commit
// copy over tags in the rbyd in order
lfsr_srid_t rid = start_rid;
lfsr_tag_t tag = 0;
while (true) {
lfsr_rid_t weight;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, &mdir->rbyd,
rid, tag+1,
&rid, &tag, &weight, &data);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
// end of range? note the use of rid+1 and unsigned comparison here to
// treat end_rid=-1 as "unbounded" in such a way that rid=-1 is still
// included
if ((lfs_size_t)(rid + 1) > (lfs_size_t)end_rid) {
break;
}
// found an inlined sprout? we can just copy this like normal but
// we need to update any opened inlined files
if (tag == LFSR_TAG_DATA) {
err = lfsr_rbyd_appendcompactattr(lfs, &mdir_->rbyd,
tag, weight, data);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
err = lfsr_sprout_compact(lfs, &mdir_->rbyd, &data,
&data);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// found an inlined shrub? we need to compact the shrub as well to
// bring it along with us
} else if (tag == LFSR_TAG_BSHRUB) {
lfsr_shrub_t shrub;
err = lfsr_data_readshrub(lfs, &data, mdir,
&shrub);
if (err) {
return err;
}
// compact our shrub
err = lfsr_shrub_compact(lfs, &mdir_->rbyd, &shrub,
&shrub);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// write the new shrub tag
uint8_t shrub_buf[LFSR_SHRUB_DSIZE];
err = lfsr_rbyd_appendcompactattr(lfs, &mdir_->rbyd,
tag, weight, lfsr_data_fromshrub(
&shrub, shrub_buf));
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
} else {
// write the tag
err = lfsr_rbyd_appendcompactattr(lfs, &mdir_->rbyd,
tag, weight, data);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
}
int err = lfsr_rbyd_appendcompaction(lfs, &mdir_->rbyd, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// we're not quite done! we also need to bring over any unsynced files
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
lfsr_file_t *file = (lfsr_file_t*)opened;
// belongs to our mdir?
if (file->m.type != LFS_TYPE_REG
|| lfsr_mdir_cmp(&file->m.mdir, mdir) != 0
|| lfsr_mid_rid(lfs, file->m.mdir.mid) < start_rid
|| (lfsr_rid_t)lfsr_mid_rid(lfs, file->m.mdir.mid)
>= (lfsr_rid_t)end_rid) {
continue;
}
// inlined sprout?
if (lfsr_bshrub_isbsprout(&file->m.mdir, &file->bshrub)
// only compact once, first compact should stage the new block
&& file->bshrub_.u.bsprout.u.disk.block
!= mdir_->rbyd.blocks[0]) {
err = lfsr_rbyd_appendcompactattr(lfs, &mdir_->rbyd,
LFSR_TAG_SHRUB(DATA), 0, file->bshrub.u.bsprout);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
err = lfsr_sprout_compact(lfs, &mdir_->rbyd,
&file->bshrub_.u.bsprout, &file->bshrub.u.bsprout);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// inlined shrub?
} else if (lfsr_bshrub_isbshrub(&file->m.mdir, &file->bshrub)
// only compact once, first compact should stage the new block
&& file->bshrub.u.bshrub.blocks[0]
!= mdir_->rbyd.blocks[0]) {
err = lfsr_shrub_compact(lfs, &mdir_->rbyd,
&file->bshrub_.u.bshrub, &file->bshrub.u.bshrub);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
}
return 0;
}
// mid-level mdir commit, this one will at least compact on overflow
static int lfsr_mdir_commit_(lfs_t *lfs, lfsr_mdir_t *mdir,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
lfsr_srid_t *split_rid_,
lfsr_smid_t mid, const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// try to commit
int err = lfsr_mdir_commit__(lfs, mdir, start_rid, end_rid,
mid, attrs, attr_count);
if (err) {
if (err == LFS_ERR_RANGE) {
goto compact;
}
return err;
}
return 0;
compact:;
// can't commit, try to compact
// check if we're within our compaction threshold
lfs_ssize_t estimate = lfsr_mdir_estimate__(lfs, mdir, start_rid, end_rid,
split_rid_);
if (estimate < 0) {
return estimate;
}
// TODO do we need to include mdir commit overhead here? in rbyd_estimate?
if ((lfs_size_t)estimate > lfs->cfg->block_size/2) {
return LFS_ERR_RANGE;
}
// swap blocks, increment revision count
lfsr_mdir_t mdir_;
err = lfsr_mdir_swap__(lfs, &mdir_, mdir, false);
if (err) {
return err;
}
// compact our mdir
err = lfsr_mdir_compact__(lfs, &mdir_, start_rid, end_rid,
mdir);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// now try to commit again
//
// upper layers should make sure this can't fail by limiting the
// maximum commit size
err = lfsr_mdir_commit__(lfs, &mdir_, start_rid, end_rid,
mid, attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
*mdir = mdir_;
return 0;
}
static int lfsr_mroot_parent(lfs_t *lfs, const lfsr_mptr_t *mptr,
lfsr_mdir_t *mparent_) {
// we only call this when we actually have parents
LFS_ASSERT(!lfsr_mptr_ismrootanchor(mptr));
// scan list of mroots for our requested pair
lfsr_mptr_t mptr_ = LFSR_MPTR_MROOTANCHOR();
while (true) {
// fetch next possible superblock
lfsr_mdir_t mdir;
int err = lfsr_mdir_fetch(lfs, &mdir, -1, &mptr_);
if (err) {
return err;
}
// lookup next mroot
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &mdir, -1, LFSR_TAG_MROOT,
&data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// decode mdir
err = lfsr_data_readmptr(lfs, &data, &mptr_);
if (err) {
return err;
}
// found our child?
if (lfsr_mptr_cmp(&mptr_, mptr) == 0) {
*mparent_ = mdir;
return 0;
}
}
}
// mid-level mroot commit
//
// this is atomic and propagates any mroot changes up the mroot chain
//
// note! this does not handle uninlining/gstate/etc! actual commits
// to the mroot should go through lfsr_mdir_commit with lfs->mroot as
// a target
//
static int lfsr_mroot_commit_(lfs_t *lfs,
lfsr_srid_t start_rid, lfsr_srid_t end_rid,
lfsr_srid_t *split_rid_,
lfsr_smid_t mid, const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// create a copy
lfsr_mdir_t mroot_ = lfs->mroot;
// mark any copies of our mroot as unerased
lfs->mroot.rbyd.eoff = -1;
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
if (lfsr_mdir_cmp(&opened->mdir, &lfs->mroot) == 0) {
opened->mdir.rbyd.eoff = -1;
}
}
// try to commit to the mroot
int err = lfsr_mdir_commit_(lfs, &mroot_,
start_rid, end_rid, split_rid_,
mid, attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// need to update mroot chain? tail recurse, updating mroots until a
// commit sticks
lfsr_mdir_t mrootchild = lfs->mroot;
lfsr_mdir_t mrootchild_ = mroot_;
while (lfsr_mdir_cmp(&mrootchild_, &mrootchild) != 0
&& !lfsr_mdir_ismrootanchor(&mrootchild)) {
// find the mroot's parent
lfsr_mdir_t mrootparent_;
err = lfsr_mroot_parent(lfs, lfsr_mdir_mptr(&mrootchild),
&mrootparent_);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
LFS_DEBUG("Relocating mroot 0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}",
mrootchild.rbyd.blocks[0], mrootchild.rbyd.blocks[1],
mrootchild_.rbyd.blocks[0], mrootchild_.rbyd.blocks[1]);
mrootchild = mrootparent_;
// commit mrootchild
uint8_t mrootchild_buf[LFSR_MPTR_DSIZE];
err = lfsr_mdir_commit_(lfs, &mrootparent_, -1, -1, NULL,
-1, LFSR_ATTRS(
LFSR_ATTR(
MROOT, 0,
FROMMPTR(
lfsr_mdir_mptr(&mrootchild_),
mrootchild_buf))));
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
mrootchild_ = mrootparent_;
}
// uh oh, we ran out of mroot parents, need to extend mroot chain
if (lfsr_mdir_cmp(&mrootchild_, &mrootchild) != 0) {
// mrootchild should be our previous mroot anchor at this point
LFS_ASSERT(lfsr_mdir_ismrootanchor(&mrootchild));
LFS_DEBUG("Extending mroot 0x{%"PRIx32",%"PRIx32"}"
" -> 0x{%"PRIx32",%"PRIx32"}"
", 0x{%"PRIx32",%"PRIx32"}",
mrootchild.rbyd.blocks[0], mrootchild.rbyd.blocks[1],
mrootchild.rbyd.blocks[0], mrootchild.rbyd.blocks[1],
mrootchild_.rbyd.blocks[0], mrootchild_.rbyd.blocks[1]);
// compact into the new mroot anchor
lfsr_mdir_t mrootanchor_;
err = lfsr_mdir_swap__(lfs, &mrootanchor_, &mrootchild, -1);
if (err) {
return err;
}
// copy only the config over
lfsr_tag_t tag = 0;
while (true) {
lfsr_srid_t rid;
lfsr_rid_t weight;
lfsr_data_t data;
err = lfsr_rbyd_lookupnext(lfs, &mrootchild.rbyd,
-1, tag+1,
&rid, &tag, &weight, &data);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
if (rid != -1 || lfsr_tag_suptype(tag) != LFSR_TAG_CONFIG) {
break;
}
// write the tag
err = lfsr_rbyd_appendcompactattr(lfs, &mrootanchor_.rbyd,
tag, weight, data);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
err = lfsr_rbyd_appendcompaction(lfs, &mrootanchor_.rbyd, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// and commit our new mroot
uint8_t mrootchild_buf[LFSR_MPTR_DSIZE];
err = lfsr_mdir_commit__(lfs, &mrootanchor_, -1, -1, -1, LFSR_ATTRS(
LFSR_ATTR(
SUBMASK(MROOT), 0,
FROMMPTR(lfsr_mdir_mptr(&mrootchild_), mrootchild_buf))));
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// success? update in-device state, we must not error at this point
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
if (lfsr_mdir_cmp(&opened->mdir, &lfs->mroot) == 0) {
// update any opened mdirs in our mroot
opened->mdir.rbyd = mroot_.rbyd;
// update staged changes
if (opened->type == LFS_TYPE_REG) {
lfsr_file_t *file = (lfsr_file_t*)opened;
file->bshrub = file->bshrub_;
}
}
}
// and save our new mroot
lfs->mroot = mroot_;
return 0;
}
// high-level mtree commit
//
// this is atomic and propagates any mroot changes up the mroot chain
//
static int lfsr_mtree_commit_(lfs_t *lfs, lfsr_smid_t mid,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
lfsr_btree_t mtree_;
// new mtree?
if (lfsr_mtree_ismptr(lfs)) {
int err = lfsr_btree_alloc(lfs, &mtree_);
if (err) {
return err;
}
} else {
// create a copy
mtree_ = lfs->mtree.u.btree;
// mark as unerased in case of failure
lfs->mtree.u.btree.eoff = -1;
}
// commit to mtree
int err = lfsr_btree_commit(lfs, &mtree_,
lfsr_mid_bid(lfs, mid),
attrs, attr_count);
if (err) {
return err;
}
// mtree should never go to zero since we will always have a
// root bookmark
LFS_ASSERT(mtree_.weight > 0);
// commit new mtree into our mroot
//
// Note if we every have an mtree, mroot should have no files,
// so we set end_rid=0 here which will delete any files. Above
// layers rely on this.
//
uint8_t mtree_buf[LFSR_BTREE_DSIZE];
err = lfsr_mroot_commit_(lfs, -1, 0, NULL, -1, LFSR_ATTRS(
LFSR_ATTR(SUBMASK(MTREE), 0, FROMBTREE(&mtree_, mtree_buf))));
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// success? update in-device state, we must not error at this point
// save our new mtree
lfs->mtree.u.btree = mtree_;
return 0;
}
// high-level mdir commit
//
// this is atomic and updates any opened mdirs, lfs_t, gstate, etc
//
static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
LFS_ASSERT(mdir->mid == -1
|| lfsr_mtree_isnull(lfs)
|| mdir->rbyd.weight > 0);
LFS_ASSERT(lfsr_mid_rid(lfs, mdir->mid) < mdir->rbyd.weight);
// reset gdelta for new commit
lfsr_fs_flushgdelta(lfs);
// create a copy
lfsr_mdir_t mdir_ = *mdir;
for (lfs_size_t i = 0; i < attr_count; i++) {
// parse out any pending gstate, these will get automatically
// xored with on-disk gdeltas in lower-level functions
if (attrs[i].tag == LFSR_TAG_GRM) {
// encode to disk
lfsr_grm_t *grm = (lfsr_grm_t*)attrs[i].data.u.buf.buffer;
lfsr_data_fromgrm(grm, lfs->grm_d);
// xor with our current gstate to find our initial gdelta
int err = lfsr_grm_xor(lfs, lfs->grm_d,
LFSR_DATA_BUF(lfs->grm_g, LFSR_GRM_DSIZE));
if (err) {
return err;
}
}
}
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
// mark any copies of our mdir as unerased in case we fail
//
// note we need to not mark the mroot as unerased, because that
// would force the mroot to always compact
//
if (lfsr_mdir_cmp(&opened->mdir, mdir) == 0) {
opened->mdir.rbyd.eoff = -1;
}
// stage any bsprouts/bshrubs
if (opened->type == LFS_TYPE_REG) {
lfsr_file_t *file = (lfsr_file_t*)opened;
file->bshrub_ = file->bshrub;
}
}
// attempt to commit/compact the mdir normally
lfsr_srid_t split_rid;
int err;
// mroot? we need special handling to propagate up the mroot chain
if (lfsr_mdir_cmp(mdir, &lfs->mroot) == 0) {
err = lfsr_mroot_commit_(lfs, -1, -1, &split_rid,
mdir->mid, attrs, attr_count);
if (err && err != LFS_ERR_RANGE) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// keep mdir_ in sync with mroot
mdir_.rbyd = lfs->mroot.rbyd;
// otherwise commit normally
} else {
// mark our mdir as unerased in case we fail
mdir->rbyd.eoff = -1;
err = lfsr_mdir_commit_(lfs, &mdir_, -1, -1, &split_rid,
mdir->mid, attrs, attr_count);
if (err && err != LFS_ERR_RANGE && err != LFS_ERR_NOENT) {
return err;
}
}
// handle possible mtree updates, this gets a bit messy
lfsr_mdir_t msibling_;
lfsr_smid_t mdelta = 0;
// need to split?
if (err == LFS_ERR_RANGE) {
// this should not happen unless we can't fit our mroot's metadata
LFS_ASSERT(mdir->mid != -1 || lfsr_mtree_isnull(lfs));
// if we're not the mroot, we need to consume the gstate so
// we don't lose any info during the split
//
// we do this here so we don't have to worry about corner cases
// with dropping mdirs during a split
if (!lfsr_mtree_isnull(lfs)) {
err = lfsr_fs_consumegdelta(lfs, mdir);
if (err) {
return err;
}
}
// compact into new mdir tags < split_rid
err = lfsr_mdir_alloc__(lfs, &mdir_, lfs_smax32(mdir->mid, 0));
if (err) {
return err;
}
err = lfsr_mdir_compact__(lfs, &mdir_, 0, split_rid,
mdir);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
err = lfsr_mdir_commit__(lfs, &mdir_, 0, split_rid,
mdir_.mid, attrs, attr_count);
if (err && err != LFS_ERR_NOENT) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// compact into new mdir tags >= split_rid
err = lfsr_mdir_alloc__(lfs, &msibling_, lfs_smax32(mdir->mid, 0));
if (err) {
return err;
}
err = lfsr_mdir_compact__(lfs, &msibling_, split_rid, -1,
mdir);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
err = lfsr_mdir_commit__(lfs, &msibling_, split_rid, -1,
mdir_.mid, attrs, attr_count);
if (err && err != LFS_ERR_NOENT) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// adjust our sibling's mid after committing attrs
msibling_.mid += lfsr_mweight(lfs);
LFS_DEBUG("Splitting mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}, "
"0x{%"PRIx32",%"PRIx32"}",
mdir->mid >> lfs->mbits,
mdir->rbyd.blocks[0], mdir->rbyd.blocks[1],
mdir_.rbyd.blocks[0], mdir_.rbyd.blocks[1],
msibling_.rbyd.blocks[0], msibling_.rbyd.blocks[1]);
// because of defered commits, children can be reduced to zero
// when splitting, need to catch this here
// both siblings reduced to zero
if (mdir_.rbyd.weight == 0 && msibling_.rbyd.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir_.mid >> lfs->mbits,
mdir_.rbyd.blocks[0], mdir_.rbyd.blocks[1]);
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
msibling_.mid >> lfs->mbits,
msibling_.rbyd.blocks[0], msibling_.rbyd.blocks[1]);
goto drop;
// one sibling reduced to zero
} else if (mdir_.rbyd.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir_.mid >> lfs->mbits,
mdir_.rbyd.blocks[0], mdir_.rbyd.blocks[1]);
mdir_.rbyd = msibling_.rbyd;
goto relocate;
// other sibling reduced to zero
} else if (msibling_.rbyd.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
msibling_.mid >> lfs->mbits,
msibling_.rbyd.blocks[0], msibling_.rbyd.blocks[1]);
goto relocate;
}
// no siblings reduced to zero, update our mtree
mdelta = +lfsr_mweight(lfs);
// fix any pending grms
for (lfs_size_t i = 0; i < attr_count; i++) {
if (attrs[i].tag == LFSR_TAG_GRM) {
// Assuming we already xored our gdelta with the grm, we first
// need to xor the grm out of the gdelta. We can't just zero
// the gdelta because we may have picked up extra gdelta from
// split/dropped mdirs
//
// gd' = gd xor (grm' xor grm)
//
lfsr_grm_t *grm = (lfsr_grm_t*)attrs[i].data.u.buf.buffer;
uint8_t grm_buf[LFSR_GRM_DSIZE];
err = lfsr_grm_xor(lfs, lfs->grm_d,
lfsr_data_fromgrm(grm, grm_buf));
if (err) {
return err;
}
// fix our grm
for (int j = 0; j < 2; j++) {
if (lfsr_mid_bid(lfs, grm->rms[j])
== lfsr_mid_bid(lfs, lfs_smax32(mdir->mid, 0))) {
if (lfsr_mid_rid(lfs, grm->rms[j])
>= mdir_.rbyd.weight) {
grm->rms[j] += lfsr_mweight(lfs)
- mdir_.rbyd.weight;
}
} else if (grm->rms[j] > mdir->mid) {
grm->rms[j] += mdelta;
}
}
// xor our fix into our gdelta
err = lfsr_grm_xor(lfs, lfs->grm_d,
lfsr_data_fromgrm(grm, grm_buf));
if (err) {
return err;
}
}
}
// lookup first name in sibling to use as the split name
//
// note we need to do this after playing out pending attrs in
// case they introduce a new name!
lfsr_data_t split_data;
err = lfsr_rbyd_sublookup(lfs, &msibling_.rbyd, 0, LFSR_TAG_NAME,
NULL, &split_data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// new mtree?
if (lfsr_mtree_ismptr(lfs)) {
uint8_t mdir_buf[LFSR_MPTR_DSIZE];
uint8_t msibling_buf[LFSR_MPTR_DSIZE];
err = lfsr_mtree_commit_(lfs, -1, LFSR_ATTRS(
LFSR_ATTR(
MDIR, +lfsr_mweight(lfs),
FROMMPTR(lfsr_mdir_mptr(&mdir_), mdir_buf)),
LFSR_ATTR(
NAME, +lfsr_mweight(lfs), DATA(split_data)),
LFSR_ATTR(
MDIR, 0,
FROMMPTR(lfsr_mdir_mptr(&msibling_), msibling_buf))));
if (err) {
return err;
}
// update our mtree
} else {
uint8_t mdir_buf[LFSR_MPTR_DSIZE];
uint8_t msibling_buf[LFSR_MPTR_DSIZE];
err = lfsr_mtree_commit_(lfs, mdir_.mid, LFSR_ATTRS(
LFSR_ATTR(
MDIR, 0, FROMMPTR(lfsr_mdir_mptr(&mdir_), mdir_buf)),
LFSR_ATTR(
NAME, +lfsr_mweight(lfs), DATA(split_data)),
LFSR_ATTR(
MDIR, 0,
FROMMPTR(lfsr_mdir_mptr(&msibling_), msibling_buf))));
if (err) {
return err;
}
}
// need to drop?
} else if (err == LFS_ERR_NOENT) {
LFS_DEBUG("Dropping mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"}",
mdir_.mid >> lfs->mbits,
mdir_.rbyd.blocks[0], mdir_.rbyd.blocks[1]);
// consume gstate so we don't lose any info
err = lfsr_fs_consumegdelta(lfs, mdir);
if (err) {
return err;
}
drop:;
mdelta = -lfsr_mweight(lfs);
// TODO deduplicate?
// fix any pending grms
for (lfs_size_t i = 0; i < attr_count; i++) {
if (attrs[i].tag == LFSR_TAG_GRM) {
// Assuming we already xored our gdelta with the grm, we first
// need to xor the grm out of the gdelta. We can't just zero
// the gdelta because we may have picked up extra gdelta from
// split/dropped mdirs
//
// gd' = gd xor (grm' xor grm)
//
lfsr_grm_t *grm = (lfsr_grm_t*)attrs[i].data.u.buf.buffer;
uint8_t grm_buf[LFSR_GRM_DSIZE];
err = lfsr_grm_xor(lfs, lfs->grm_d,
lfsr_data_fromgrm(grm, grm_buf));
if (err) {
return err;
}
// fix our grm
for (int j = 0; j < 2; j++) {
if (grm->rms[j] > mdir->mid) {
grm->rms[j] += mdelta;
}
}
// xor our fix into our gdelta
err = lfsr_grm_xor(lfs, lfs->grm_d,
lfsr_data_fromgrm(grm, grm_buf));
if (err) {
return err;
}
}
}
// we should never drop a direct mdir, because we always have our
// root bookmark
LFS_ASSERT(!lfsr_mtree_ismptr(lfs));
// update our mtree
err = lfsr_mtree_commit_(lfs, mdir_.mid, LFSR_ATTRS(
LFSR_ATTR(RM, -lfsr_mweight(lfs), NULL())));
if (err) {
return err;
}
// need to relocate?
} else if (lfsr_mdir_cmp(mdir, &mdir_) != 0
&& lfsr_mdir_cmp(&mdir_, &lfs->mroot) != 0) {
LFS_DEBUG("Relocating mdir %"PRId32" "
"0x{%"PRIx32",%"PRIx32"} -> 0x{%"PRIx32",%"PRIx32"}",
mdir->mid >> lfs->mbits,
mdir->rbyd.blocks[0], mdir->rbyd.blocks[1],
mdir_.rbyd.blocks[0], mdir_.rbyd.blocks[1]);
relocate:;
// new mtree?
if (lfsr_mtree_ismptr(lfs)) {
uint8_t mdir_buf[LFSR_MPTR_DSIZE];
err = lfsr_mroot_commit_(lfs, -1, 0, NULL, -1, LFSR_ATTRS(
LFSR_ATTR(
SUBMASK(MDIR), 0,
FROMMPTR(lfsr_mdir_mptr(&mdir_), mdir_buf))));
if (err) {
return err;
}
lfs->mtree = LFSR_MTREE_MPTR(
*lfsr_mdir_mptr(&mdir_),
lfsr_mweight(lfs));
} else {
// update our mtree
uint8_t mdir_buf[LFSR_MPTR_DSIZE];
err = lfsr_mtree_commit_(lfs, mdir_.mid, LFSR_ATTRS(
LFSR_ATTR(
MDIR, 0, FROMMPTR(lfsr_mdir_mptr(&mdir_), mdir_buf))));
if (err) {
return err;
}
}
}
// success? update in-device state, we must not error at this point
// gstate must have been committed by a lower-level function at this point
LFS_ASSERT(lfsr_grm_iszero(lfs->grm_d));
// TODO merge with attr updates below?
for (lfs_size_t i = 0; i < attr_count; i++) {
// update any gstate
if (attrs[i].tag == LFSR_TAG_GRM) {
lfs->grm = *(lfsr_grm_t*)attrs[i].data.u.buf.buffer;
// keep track of the exact encoding on-disk
lfsr_data_fromgrm(&lfs->grm, lfs->grm_g);
}
}
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
// update staged changes
if (opened->type == LFS_TYPE_REG) {
lfsr_file_t *file = (lfsr_file_t*)opened;
file->bshrub = file->bshrub_;
}
// avoid double updating current mdir
if (&opened->mdir == mdir) {
continue;
}
// first play out any attrs that change our mid
lfsr_srid_t mid = mdir->mid;
for (lfs_size_t i = 0; i < attr_count; i++) {
// adjust opened mdirs?
if (lfsr_mdir_cmp(&opened->mdir, mdir) == 0
&& opened->mdir.mid >= mid) {
// replaced?
if (opened->mdir.mid == mid - attrs[i].delta
&& lfsr_tag_issupwide(attrs[i].tag)) {
opened->flags |= LFS_F_ZOMBIE
| LFS_F_UNSYNC
| LFS_O_DESYNC;
opened->flags &= ~LFS_F_ORPHAN;
// removed?
} else if (opened->mdir.mid < mid - attrs[i].delta) {
// we should not be removing opened regular files
LFS_ASSERT(opened->type != LFS_TYPE_REG);
opened->flags |= LFS_F_ZOMBIE;
opened->mdir.mid = mid;
} else if (opened->mdir.mid > mid) {
opened->mdir.mid += attrs[i].delta;
// adjust dir position?
if (opened->type == LFS_TYPE_DIR) {
((lfsr_dir_t*)opened)->pos += attrs[i].delta;
} else if (opened->type == LFS_TYPE_BOOKMARK) {
((lfsr_dir_t*)(opened-1))->pos -= attrs[i].delta;
}
}
} else if (opened->mdir.mid > mdir->mid) {
// adjust dir position?
if (opened->type == LFS_TYPE_DIR) {
((lfsr_dir_t*)opened)->pos += attrs[i].delta;
} else if (opened->type == LFS_TYPE_BOOKMARK) {
((lfsr_dir_t*)(opened-1))->pos -= attrs[i].delta;
}
}
// adjust mid
mid += attrs[i].delta;
}
// update any opened mdirs if we had a split or drop
if (lfsr_mdir_cmp(&opened->mdir, mdir) == 0) {
if (mdelta > 0
&& lfsr_mid_rid(lfs, opened->mdir.mid)
>= mdir_.rbyd.weight) {
opened->mdir.mid += lfsr_mweight(lfs)
- mdir_.rbyd.weight;
opened->mdir.rbyd = msibling_.rbyd;
} else {
opened->mdir.rbyd = mdir_.rbyd;
}
} else if (opened->mdir.mid > mdir->mid) {
opened->mdir.mid += mdelta;
}
}
// adjust mid if we created a new file
if (attr_count > 0
&& !lfsr_tag_isgrow(attrs[0].tag)
&& attrs[0].delta > 0) {
mdir->mid += 1;
}
// update mdir to follow requested rid
if (mdir->mid == -1) {
mdir->rbyd = lfs->mroot.rbyd;
} else if (mdelta > 0
&& lfsr_mid_rid(lfs, mdir->mid) >= mdir_.rbyd.weight) {
mdir->mid += lfsr_mweight(lfs) - mdir_.rbyd.weight;
mdir->rbyd = msibling_.rbyd;
} else {
mdir->rbyd = mdir_.rbyd;
}
return 0;
}
/// Path/name lookup stuff ///
// lookup names in an mdir
//
// if not found, rid will be the best place to insert
static int lfsr_mdir_namelookup(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_did_t did, const char *name, lfs_size_t name_size,
lfsr_smid_t *mid_, lfsr_tag_t *tag_, lfsr_data_t *data_) {
// default to mid_ = 0, this blanket assignment is the only way to
// keep GCC happy
if (mid_) {
*mid_ = 0;
}
// empty mdir?
if (mdir->rbyd.weight == 0) {
return LFS_ERR_NOENT;
}
lfsr_srid_t rid;
lfsr_tag_t tag;
lfs_scmp_t cmp = lfsr_rbyd_namelookup(lfs, &mdir->rbyd,
did, name, name_size,
&rid, &tag, NULL, data_);
if (cmp < 0) {
LFS_ASSERT(cmp != LFS_ERR_NOENT);
return cmp;
}
// adjust mid if necessary
lfsr_smid_t mid = LFSR_MID(lfs,
mdir->mid,
(lfs_cmp(cmp) > 0) ? rid-1 : rid);
// intercept pending grms here and pretend they're orphaned files
//
// fortunately pending grms/orphaned files have roughly the same
// semantics, and it's easier to manage the implied mid gap in
// higher-levels
if (lfsr_grm_isrm(&lfs->grm, mid)) {
tag = LFSR_TAG_ORPHAN;
}
if (mid_) {
*mid_ = mid;
}
if (tag_) {
*tag_ = tag;
}
return (lfs_cmp(cmp) == 0) ? 0 : LFS_ERR_NOENT;
}
// lookup names in our mtree
//
// if not found, rid will be the best place to insert
static int lfsr_mtree_namelookup(lfs_t *lfs,
lfsr_did_t did, const char *name, lfs_size_t name_size,
lfsr_mdir_t *mdir_, lfsr_tag_t *tag_, lfsr_data_t *data_) {
// do we only have mroot?
lfsr_mdir_t mdir;
if (lfsr_mtree_isnull(lfs)) {
mdir = lfs->mroot;
// treat inlined mdir as mid=0
mdir.mid = 0;
// direct mdir?
} else if (lfsr_mtree_ismptr(lfs)) {
int err = lfsr_mdir_fetch(lfs, &mdir, 0, &lfs->mtree.u.mptr.mptr);
if (err) {
return err;
}
// lookup name in actual mtree
} else {
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_data_t data;
lfs_scmp_t cmp = lfsr_btree_namelookup(lfs, &lfs->mtree.u.btree,
did, name, name_size,
&bid, &tag, &weight, &data);
if (cmp < 0) {
LFS_ASSERT(cmp != LFS_ERR_NOENT);
return cmp;
}
LFS_ASSERT(tag == LFSR_TAG_MDIR);
LFS_ASSERT(weight == lfsr_mweight(lfs));
// decode mdir
lfsr_mptr_t mptr;
int err = lfsr_data_readmptr(lfs, &data, &mptr);
if (err) {
return err;
}
// fetch mdir
err = lfsr_mdir_fetch(lfs, &mdir, bid-(weight-1), &mptr);
if (err) {
return err;
}
}
// and finally lookup name in our mdir
lfsr_smid_t mid;
int err = lfsr_mdir_namelookup(lfs, &mdir,
did, name, name_size,
&mid, tag_, data_);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// update mdir with best place to insert even if we fail
mdir.mid = mid;
if (mdir_) {
*mdir_ = mdir;
}
return err;
}
// special directory-ids
enum {
LFSR_DID_ROOT = 0,
};
// lookup full paths in our mtree
//
// note the errors here are a bit weird, because paths can have some weird
// corner-cases during lookup, and we want to report all the different
// conditions:
//
// - 0 => path is valid, file NOT found
// - EXIST => path is valid, file found
// - INVAL => path is valid, but points to root
// - NOENT => path is NOT valid, intermediate dir missing
// - NOTDIR => path is NOT valid, intermediate dir is not a dir
//
// if not found, mdir_/did_/name_ will at least be set up
// with what should be the parent
static int lfsr_mtree_pathlookup(lfs_t *lfs, const char *path,
lfsr_mdir_t *mdir_, lfsr_tag_t *tag_,
lfsr_did_t *did_, const char **name_, lfs_size_t *name_size_) {
// setup root
lfsr_mdir_t mdir = {.mid = -1};
lfsr_tag_t tag = LFSR_TAG_DIR;
lfsr_did_t did = LFSR_DID_ROOT;
// we reduce path to a single name if we can find it
const char *name = path;
lfs_size_t name_size = 0;
while (true) {
// skip slashes
path += strspn(path, "/");
lfs_size_t name_size__ = strcspn(path, "/");
// skip '.' and root '..'
if ((name_size__ == 1 && memcmp(path, ".", 1) == 0)
|| (name_size__ == 2 && memcmp(path, "..", 2) == 0)) {
path += name_size__;
goto next;
}
// skip if matched by '..' in name
const char *suffix = path + name_size__;
lfs_size_t suffix_size;
int depth = 1;
while (true) {
suffix += strspn(suffix, "/");
suffix_size = strcspn(suffix, "/");
if (suffix_size == 0) {
break;
}
if (suffix_size == 2 && memcmp(suffix, "..", 2) == 0) {
depth -= 1;
if (depth == 0) {
path = suffix + suffix_size;
goto next;
}
} else {
depth += 1;
}
suffix += suffix_size;
}
// found end of path, we must be done parsing our path now
if (path[0] == '\0') {
if (mdir_) {
*mdir_ = mdir;
}
if (tag_) {
*tag_ = tag;
}
if (did_) {
*did_ = did;
}
if (name_) {
*name_ = name;
}
if (name_size_) {
*name_size_ = name_size;
}
// the root dir doesn't have an mdir really, so it's always
// a special case
return (mdir.mid == -1)
? LFS_ERR_INVAL
: LFS_ERR_EXIST;
}
// found another name
name = path;
name_size = name_size__;
// only continue if we hit a directory
if (tag != LFSR_TAG_DIR) {
return (tag == LFSR_TAG_ORPHAN)
? LFS_ERR_NOENT
: LFS_ERR_NOTDIR;
}
// read the next did from the mdir if this is not the root
if (mdir.mid != -1) {
lfsr_data_t data;
int err = lfsr_mdir_lookup(lfs, &mdir, mdir.mid, LFSR_TAG_DID,
&data);
if (err) {
return err;
}
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&did);
if (err) {
return err;
}
}
// lookup up this name in the mtree
int err = lfsr_mtree_namelookup(lfs, did, name, name_size,
&mdir, &tag, NULL);
if (err) {
// report where to insert if we are the last name in our path
if (err == LFS_ERR_NOENT && strchr(name, '/') == NULL) {
if (mdir_) {
*mdir_ = mdir;
}
if (tag_) {
*tag_ = tag;
}
if (did_) {
*did_ = did;
}
if (name_) {
*name_ = name;
}
if (name_size_) {
*name_size_ = name_size;
}
return 0;
}
return err;
}
// go on to next name
path += name_size;
next:;
}
}
/// Traversal stuff ///
// incremental filesystem traversal
typedef struct lfsr_traversal {
// core traversal state
uint8_t flags;
uint8_t state;
union {
// cycle detection state, only valid when traversing the mroot chain
struct {
lfsr_mptr_t mptr;
lfs_block_t step;
uint8_t power;
} mtortoise;
// btree traversal state, only valid when traversing the mtree
lfsr_btraversal_t mtraversal;
// opened file state, only valid when traversing opened files
const lfsr_opened_t *opened;
} u;
// we really don't want to pay the RAM cost for a full file,
// so only store the relevant bits, is this a hack? yes
struct {
lfsr_opened_t *next;
uint8_t type;
uint16_t flags;
lfsr_mdir_t mdir;
lfsr_bshrub_t bshrub;
} file;
lfsr_btraversal_t btraversal;
} lfsr_traversal_t;
enum {
// traverse all blocks in the filesystem
LFSR_TRAVERSAL_ALL = 0x1,
// validate checksums while traversing
LFSR_TRAVERSAL_VALIDATE = 0x2,
};
// traversing littlefs is a bit complex, so we use a state machine to keep
// track of where we are
enum {
LFSR_TRAVERSAL_MROOTANCHOR = 0,
LFSR_TRAVERSAL_MROOTCHAIN = 1,
LFSR_TRAVERSAL_MTREE = 2,
LFSR_TRAVERSAL_MDIR = 3,
LFSR_TRAVERSAL_MDIRBTREE = 4,
LFSR_TRAVERSAL_OPENED = 5,
LFSR_TRAVERSAL_OPENEDBTREE = 6,
LFSR_TRAVERSAL_DONE = 7,
};
#define LFSR_TRAVERSAL(_flags) \
((lfsr_traversal_t){ \
.flags=_flags, \
.state=LFSR_TRAVERSAL_MROOTANCHOR, \
.u.mtortoise.mptr={{0, 0}}, \
.u.mtortoise.step=0, \
.u.mtortoise.power=0})
static inline bool lfsr_traversal_isall(const lfsr_traversal_t *traversal) {
return traversal->flags & LFSR_TRAVERSAL_ALL;
}
static inline bool lfsr_traversal_isvalidate(
const lfsr_traversal_t *traversal) {
return traversal->flags & LFSR_TRAVERSAL_VALIDATE;
}
// needed in lfsr_traversal_read
static int lfsr_bshrub_traverse(lfs_t *lfs, const lfsr_file_t *file,
lfsr_btraversal_t *btraversal,
lfsr_bid_t *bid_, lfsr_tinfo_t *tinfo_);
static int lfsr_traversal_read(lfs_t *lfs, lfsr_traversal_t *traversal,
lfsr_tinfo_t *tinfo_) {
while (true) {
switch (traversal->state) {
// start with the mrootanchor 0x{0,1}
//
// note we make sure to include all mroots in our mroot chain!
//
case LFSR_TRAVERSAL_MROOTANCHOR:;
// fetch the first mroot 0x{0,1}
int err = lfsr_mdir_fetch(lfs, &traversal->file.mdir,
-1, &LFSR_MPTR_MROOTANCHOR());
if (err) {
return err;
}
// transition to traversing the mroot chain
traversal->state = LFSR_TRAVERSAL_MROOTCHAIN;
if (tinfo_) {
tinfo_->tag = LFSR_TAG_MDIR;
tinfo_->u.mdir = traversal->file.mdir;
}
return 0;
// traverse the mroot chain, checking for mroot/mtree/mdir
case LFSR_TRAVERSAL_MROOTCHAIN:;
// lookup mroot, if we find one this is a fake mroot
lfsr_tag_t tag;
lfsr_data_t data;
err = lfsr_mdir_sublookup(lfs, &traversal->file.mdir,
-1, LFSR_TAG_STRUCT,
&tag, &data);
if (err) {
// if we have no mtree/mdir (inlined mdir), we need to traverse
// any files in our mroot next
if (err == LFS_ERR_NOENT) {
traversal->file.mdir.mid = 0;
traversal->state = LFSR_TRAVERSAL_MDIR;
continue;
}
return err;
}
// found a new mroot
if (tag == LFSR_TAG_MROOT) {
lfsr_mptr_t mptr;
err = lfsr_data_readmptr(lfs, &data, &mptr);
if (err) {
return err;
}
// detect cycles with Brent's algorithm
//
// note we only check for cycles in the mroot chain, the btree
// inner nodes require checksums of their pointers, so creating
// a valid cycle is actually quite difficult
//
if (lfsr_mptr_cmp(&mptr, &traversal->u.mtortoise.mptr) == 0) {
LFS_ERROR("Cycle detected during mtree traversal "
"0x{%"PRIx32",%"PRIx32"}",
mptr.blocks[0],
mptr.blocks[1]);
return LFS_ERR_CORRUPT;
}
if (traversal->u.mtortoise.step
// TODO why cast?
== ((lfs_block_t)1 << traversal->u.mtortoise.power)) {
traversal->u.mtortoise.mptr = mptr;
traversal->u.mtortoise.step = 0;
traversal->u.mtortoise.power += 1;
}
traversal->u.mtortoise.step += 1;
// fetch this mroot
err = lfsr_mdir_fetch(lfs, &traversal->file.mdir, -1, &mptr);
if (err) {
return err;
}
if (tinfo_) {
tinfo_->tag = LFSR_TAG_MDIR;
tinfo_->u.mdir = traversal->file.mdir;
}
return 0;
// found an mdir?
} else if (tag == LFSR_TAG_MDIR) {
// fetch this mdir
lfsr_mptr_t mptr;
err = lfsr_data_readmptr(lfs, &data, &mptr);
if (err) {
return err;
}
err = lfsr_mdir_fetch(lfs, &traversal->file.mdir, 0, &mptr);
if (err) {
return err;
}
// transition to mdir traversal next
traversal->state = LFSR_TRAVERSAL_MDIR;
if (tinfo_) {
tinfo_->tag = LFSR_TAG_MDIR;
tinfo_->u.mdir = traversal->file.mdir;
}
return 0;
// found an mtree?
} else if (tag == LFSR_TAG_MTREE) {
// read the root of the mtree and return it, lfs->mtree may not
// be initialized yet
lfsr_btree_t mtree;
err = lfsr_data_readbtree(lfs, &data, &mtree);
if (err) {
return err;
}
// validate our btree nodes if requested, this just means we
// need to do a full rbyd fetch and make sure the checksums
// match
if (lfsr_traversal_isvalidate(traversal)) {
err = lfsr_rbyd_fetchvalidate(lfs, &mtree,
mtree.blocks[0], mtree.trunk, mtree.weight,
mtree.cksum);
if (err) {
return err;
}
}
// transition to traversing the mtree
traversal->state = LFSR_TRAVERSAL_MTREE;
traversal->u.mtraversal = LFSR_BTRAVERSAL();
if (tinfo_) {
tinfo_->tag = LFSR_TAG_BRANCH;
tinfo_->u.rbyd = mtree;
}
return 0;
} else {
LFS_ERROR("Weird mtree entry? 0x%"PRIx32, tag);
return LFS_ERR_CORRUPT;
}
// traverse the mtree, including both inner btree nodes and mdirs
case LFSR_TRAVERSAL_MTREE:;
// no mtree? transition to traversing any opened mdirs
if (lfsr_mtree_ismptr(lfs)) {
traversal->u.opened = lfs->opened;
traversal->state = LFSR_TRAVERSAL_OPENED;
continue;
}
// traverse through the mtree
lfsr_bid_t bid;
lfsr_tinfo_t tinfo;
err = lfsr_btree_traverse(lfs, &lfs->mtree.u.btree,
&traversal->u.mtraversal,
&bid, &tinfo);
if (err) {
// end of mtree? transition to traversing any opened mdirs
if (err == LFS_ERR_NOENT) {
traversal->u.opened = lfs->opened;
traversal->state = LFSR_TRAVERSAL_OPENED;
continue;
}
return err;
}
// wait is this the mtree's root? skip this, we assume we've already
// seen it above (this gets a bit weird because 1. mtree may be
// uninitialized in mountinited and 2. stack really matters since
// we're at the bottom of lfs_alloc)
if (tinfo.tag == LFSR_TAG_BRANCH
&& tinfo.u.rbyd.blocks[0] == lfs->mtree.u.btree.blocks[0]) {
continue;
}
// inner btree nodes already decoded
if (tinfo.tag == LFSR_TAG_BRANCH) {
// validate our btree nodes if requested, this just means we
// need to do a full rbyd fetch and make sure the checksums
// match
if (lfsr_traversal_isvalidate(traversal)) {
err = lfsr_rbyd_fetchvalidate(lfs, &tinfo.u.rbyd,
tinfo.u.rbyd.blocks[0], tinfo.u.rbyd.trunk,
tinfo.u.rbyd.weight,
tinfo.u.rbyd.cksum);
if (err) {
return err;
}
}
if (tinfo_) {
*tinfo_ = tinfo;
}
return 0;
// fetch mdir if we're on a leaf
} else if (tinfo.tag == LFSR_TAG_MDIR) {
lfsr_mptr_t mptr;
err = lfsr_data_readmptr(lfs, &tinfo.u.data, &mptr);
if (err) {
return err;
}
err = lfsr_mdir_fetch(lfs, &traversal->file.mdir,
LFSR_MID(lfs, bid, 0),
&mptr);
if (err) {
return err;
}
// transition to mdir traversal next
traversal->state = LFSR_TRAVERSAL_MDIR;
if (tinfo_) {
tinfo_->tag = LFSR_TAG_MDIR;
tinfo_->u.mdir = traversal->file.mdir;
}
return 0;
} else {
LFS_ERROR("Weird mtree entry? 0x%"PRIx32, tinfo.tag);
return LFS_ERR_CORRUPT;
}
// scan for blocks/btrees in the current mdir
case LFSR_TRAVERSAL_MDIR:;
// not traversing all blocks? have we exceeded our mdir's weight?
// return to mtree traversal
if (!lfsr_traversal_isall(traversal)
|| lfsr_mid_rid(lfs, traversal->file.mdir.mid)
>= traversal->file.mdir.rbyd.weight) {
traversal->state = LFSR_TRAVERSAL_MTREE;
continue;
}
// do we have a block/btree?
err = lfsr_mdir_lookupnext(lfs, &traversal->file.mdir,
traversal->file.mdir.mid, LFSR_TAG_DATA,
&tag, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// found a direct block?
if (err != LFS_ERR_NOENT && tag == LFSR_TAG_BLOCK) {
err = lfsr_data_readbptr(lfs, &data,
&traversal->file.bshrub.u.bptr);
if (err) {
return err;
}
// found a bshrub (inlined btree)?
} else if (err != LFS_ERR_NOENT && tag == LFSR_TAG_BSHRUB) {
err = lfsr_data_readshrub(lfs, &data, &traversal->file.mdir,
&traversal->file.bshrub.u.bshrub);
if (err) {
return err;
}
// found a btree?
} else if (err != LFS_ERR_NOENT && tag == LFSR_TAG_BTREE) {
err = lfsr_data_readbtree(lfs, &data,
&traversal->file.bshrub.u.btree);
if (err) {
return err;
}
// no? continue to next file
} else {
traversal->file.mdir.mid += 1;
continue;
}
// start traversing
traversal->btraversal = LFSR_BTRAVERSAL();
traversal->state = LFSR_TRAVERSAL_MDIRBTREE;
continue;
// scan for blocks/btrees in our opened file list
case LFSR_TRAVERSAL_OPENED:;
// not traversing all blocks? reached end of opened file list?
if (!lfsr_traversal_isall(traversal) || !traversal->u.opened) {
traversal->state = LFSR_TRAVERSAL_DONE;
continue;
}
// skip non-files
if (traversal->u.opened->type != LFS_TYPE_REG) {
traversal->u.opened = traversal->u.opened->next;
continue;
}
// start traversing the file
const lfsr_file_t *file = (const lfsr_file_t*)traversal->u.opened;
traversal->file.mdir = file->m.mdir;
traversal->file.bshrub = file->bshrub;
traversal->btraversal = LFSR_BTRAVERSAL();
traversal->state = LFSR_TRAVERSAL_OPENEDBTREE;
continue;
// traverse any file btrees, including both inner btree nodes and
// block pointers
case LFSR_TRAVERSAL_MDIRBTREE:;
case LFSR_TRAVERSAL_OPENEDBTREE:;
// traverse through our file
err = lfsr_bshrub_traverse(lfs,
(const lfsr_file_t*)&traversal->file,
&traversal->btraversal,
NULL, &tinfo);
if (err) {
if (err == LFS_ERR_NOENT) {
// end of btree? go to next file
if (traversal->state == LFSR_TRAVERSAL_MDIRBTREE) {
traversal->file.mdir.mid += 1;
traversal->state = LFSR_TRAVERSAL_MDIR;
continue;
} else if (traversal->state == LFSR_TRAVERSAL_OPENEDBTREE) {
traversal->u.opened = traversal->u.opened->next;
traversal->state = LFSR_TRAVERSAL_OPENED;
continue;
} else {
LFS_UNREACHABLE();
}
}
return err;
}
// found an inner btree node?
if (tinfo.tag == LFSR_TAG_BRANCH) {
// validate our btree nodes if requested, this just means we
// need to do a full rbyd fetch and make sure the checksums
// match
if (lfsr_traversal_isvalidate(traversal)) {
err = lfsr_rbyd_fetchvalidate(lfs, &tinfo.u.rbyd,
tinfo.u.rbyd.blocks[0], tinfo.u.rbyd.trunk,
tinfo.u.rbyd.weight,
tinfo.u.rbyd.cksum);
if (err) {
return err;
}
}
if (tinfo_) {
*tinfo_ = tinfo;
}
return 0;
// found inlined data? ignore this
} else if (tinfo.tag == LFSR_TAG_DATA) {
continue;
// found an indirect block?
} else if (tinfo.tag == LFSR_TAG_BLOCK) {
// TODO validate?
if (tinfo_) {
*tinfo_ = tinfo;
}
return 0;
} else {
LFS_UNREACHABLE();
}
case LFSR_TRAVERSAL_DONE:;
return LFS_ERR_NOENT;
default:;
LFS_UNREACHABLE();
}
}
}
/// Superblock things ///
//// TODO rm?
//// These are all leb128s, but we can expect smaller encodings
//// if we assume the version.
////
//// - 7-bit major_version => 1 byte leb128 (worst case)
//// - 7-bit minor_version => 1 byte leb128 (worst case)
//// - 7-bit cksum_type => 1 byte leb128 (worst case)
//// - 7-bit flags => 1 byte leb128 (worst case)
//// - 32-bit block_size => 5 byte leb128 (worst case)
//// - 32-bit block_count => 5 byte leb128 (worst case)
//// - 7-bit utag_limit => 1 byte leb128 (worst case)
//// - 32-bit mtree_limit => 5 byte leb128 (worst case)
//// - 32-bit attr_limit => 5 byte leb128 (worst case)
//// - 32-bit name_limit => 5 byte leb128 (worst case)
//// - 32-bit file_limit => 5 byte leb128 (worst case)
//// => 33 bytes total
////
//#define LFSR_SUPERCONFIG_DSIZE (1+1+1+1+5+5+1+5+5+5+5)
//
//#define LFSR_DATA_FROMSUPERCONFIG(_lfs, _buffer)
// lfsr_data_fromsuperconfig(_lfs, _buffer)
//
//static lfsr_data_t lfsr_data_fromsuperconfig(lfs_t *lfs,
// uint8_t buffer[static LFSR_SUPERCONFIG_DSIZE]) {
// // TODO most of these should also be in the lfs_config/lfs_t structs
//
// // note we take a shortcut for for single-byte leb128s, but these
// // are still leb128s! the top bit must be zero!
//
// // on-disk major version
// buffer[0] = LFS_DISK_VERSION_MAJOR;
// // on-disk minor version
// buffer[1] = LFS_DISK_VERSION_MINOR;
// // on-disk cksum type
// buffer[2] = 2;
// // on-disk flags
// buffer[3] = 0;
//
// // on-disk block size
// lfs_ssize_t d = 4;
// lfs_ssize_t d_ = lfs_toleb128(lfs->cfg->block_size, &buffer[d], 5);
// LFS_ASSERT(d_ >= 0);
// d += d_;
//
// // on-disk block count
// d_ = lfs_toleb128(lfs->cfg->block_count, &buffer[d], 5);
// LFS_ASSERT(d_ >= 0);
// d += d_;
//
// // on-disk mleaf limit
// d_ = lfs_toleb128(lfsr_mweight(lfs)-1, &buffer[d], 5);
// LFS_ASSERT(d_ >= 0);
// d += d_;
//
// // on-disk utag limit
// buffer[d] = 0x7f;
// d += 1;
//
// // on-disk attr limit
// d_ = lfs_toleb128(0x7fffffff, &buffer[d], 5);
// LFS_ASSERT(d_ >= 0);
// d += d_;
//
// // on-disk name limit
// d_ = lfs_toleb128(0xff, &buffer[d], 5);
// LFS_ASSERT(d_ >= 0);
// d += d_;
//
// // on-disk file limit
// d_ = lfs_toleb128(0x7fffffff, &buffer[d], 5);
// LFS_ASSERT(d_ >= 0);
// d += d_;
//
// return LFSR_DATA_BUF(buffer, d);
//}
// compatibility flags
//
// - WCOMPAT => Must understand to write to the filesystem
// - RCOMPAT => Must understand to read the filesystem
//
// note, "understanding" does not necessarily mean support
//
enum lfsr_rcompat {
LFSR_RCOMPAT_GRM = 0x01,
};
typedef uint8_t lfsr_rcompat_t;
typedef uint8_t lfsr_wcompat_t;
static inline bool lfsr_rcompat_hasgrm(lfsr_rcompat_t rcompat) {
return rcompat & LFSR_RCOMPAT_GRM;
}
static inline bool lfsr_rcompat_hasunknown(lfsr_rcompat_t rcompat) {
return rcompat & ~LFSR_RCOMPAT_GRM;
}
/// Filesystem init functions ///
static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg);
static int lfs_deinit(lfs_t *lfs);
static int lfsr_mountmroot(lfs_t *lfs, const lfsr_mdir_t *mroot) {
// has magic string?
lfsr_data_t data;
int err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_MAGIC,
&data);
if (err) {
if (err == LFS_ERR_NOENT) {
LFS_ERROR("No littlefs magic found");
return LFS_ERR_INVAL;
}
return err;
}
lfs_scmp_t cmp = lfsr_data_cmp(lfs, &data, "littlefs", 8);
if (cmp < 0) {
return cmp;
}
// treat corrupted magic as no magic
if (lfs_cmp(cmp) != 0) {
LFS_ERROR("No littlefs magic found");
return LFS_ERR_INVAL;
}
// check the disk version
err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_VERSION,
&data);
if (err) {
if (err == LFS_ERR_NOENT) {
LFS_ERROR("No littlefs version found");
return LFS_ERR_INVAL;
}
return err;
}
uint32_t major_version;
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&major_version);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (err == LFS_ERR_CORRUPT) {
major_version = -1;
}
uint32_t minor_version;
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&minor_version);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (err == LFS_ERR_CORRUPT) {
minor_version = -1;
}
if (major_version != LFS_DISK_VERSION_MAJOR
|| minor_version > LFS_DISK_VERSION_MINOR) {
LFS_ERROR("Incompatible version v%"PRId32".%"PRId32
" (!= v%"PRId32".%"PRId32")",
major_version,
minor_version,
LFS_DISK_VERSION_MAJOR,
LFS_DISK_VERSION_MINOR);
return LFS_ERR_INVAL;
}
// check for any rcompatflags, we must understand these to read
// the filesystem
err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_RCOMPATFLAGS,
&data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
data = LFSR_DATA_NULL();
}
lfsr_rcompat_t rcompat;
lfs_ssize_t size = lfsr_data_read(lfs, &data, &rcompat, 1);
if (size < 0) {
return size;
}
if (size < 1) {
rcompat = 0;
}
// unknown rcompat flags? flags must be tightly sized
if (lfsr_rcompat_hasunknown(rcompat) || lfsr_data_size(&data) > 0) {
LFS_ERROR("Incompatible rcompat flags 0x%s%"PRIx8,
(lfsr_data_size(&data) > 0) ? "??" : "",
rcompat);
return LFS_ERR_INVAL;
}
// grm supported?
if (!lfsr_rcompat_hasgrm(rcompat)) {
LFS_ERROR("Incompatible rcompat flags, no grm");
// TODO switch to read-only? upgrade?
return LFS_ERR_INVAL;
}
// check for any wcompatflags, we must understand these to write
// the filesystem
err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_WCOMPATFLAGS,
&data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
data = LFSR_DATA_NULL();
}
// unknown wcompat flags? flags must be tightly sized
if (lfsr_data_size(&data) > 0) {
LFS_ERROR("Incompatible wcompat flags 0x??");
// TODO switch to read-only?
return LFS_ERR_INVAL;
}
// check block size
err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_BLOCKSIZE,
&data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
uint32_t block_size = 0;
if (err != LFS_ERR_NOENT) {
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&block_size);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (err == LFS_ERR_CORRUPT) {
block_size = -1;
}
}
if (block_size != lfs->cfg->block_size-1) {
LFS_ERROR("Incompatible block size %"PRId32" (!= %"PRId32")",
block_size+1,
lfs->cfg->block_size);
return LFS_ERR_INVAL;
}
// check block count
err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_BLOCKCOUNT,
&data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
uint32_t block_count = 0;
if (err != LFS_ERR_NOENT) {
err = lfsr_data_readleb128(lfs, &data,
(int32_t*)&block_count);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (err == LFS_ERR_CORRUPT) {
block_count = -1;
}
}
if (block_count != lfs->cfg->block_count-1) {
LFS_ERROR("Incompatible block count %"PRId32" (!= %"PRId32")",
block_count+1,
lfs->cfg->block_count);
return LFS_ERR_INVAL;
}
// read the name limit
err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_NAMELIMIT,
&data);
if (err) {
if (err == LFS_ERR_NOENT) {
LFS_ERROR("No name limit found");
return LFS_ERR_INVAL;
}
return err;
}
uint32_t name_limit;
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&name_limit);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (err == LFS_ERR_CORRUPT) {
name_limit = -1;
}
if (name_limit > lfs->name_limit) {
LFS_ERROR("Incompatible name limit (%"PRId32" > %"PRId32")",
name_limit,
lfs->name_limit);
return LFS_ERR_INVAL;
}
lfs->name_limit = name_limit;
// read the size limit
err = lfsr_mdir_lookup(lfs, mroot, -1, LFSR_TAG_SIZELIMIT,
&data);
if (err) {
if (err == LFS_ERR_NOENT) {
LFS_ERROR("No size limit found");
return LFS_ERR_INVAL;
}
return err;
}
uint32_t size_limit;
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&size_limit);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (err == LFS_ERR_CORRUPT) {
size_limit = -1;
}
if (size_limit > lfs->size_limit) {
LFS_ERROR("Incompatible size limit (%"PRId32" > %"PRId32")",
size_limit,
lfs->size_limit);
return LFS_ERR_INVAL;
}
lfs->size_limit = size_limit;
// check for unknown configs
lfsr_tag_t tag;
err = lfsr_mdir_lookupnext(lfs, mroot, -1, LFSR_TAG_SIZELIMIT+1,
&tag, NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT
&& lfsr_tag_suptype(tag) == LFSR_TAG_CONFIG) {
LFS_ERROR("Unknown config 0x%04"PRIx16,
tag);
return LFS_ERR_INVAL;
}
return 0;
}
static int lfsr_mountinited(lfs_t *lfs) {
// zero gdeltas, we'll read these from our mdirs
lfsr_fs_flushgdelta(lfs);
// default to no mtree, this is allowed and implies all files are inlined
// in the mroot
lfs->mtree = LFSR_MTREE_NULL();
// traverse the mtree rooted at mroot 0x{1,0}
//
// we do validate btree inner nodes here, how can we trust our
// mdirs are valid if we haven't checked the btree inner nodes at
// least once?
lfsr_traversal_t traversal = LFSR_TRAVERSAL(LFSR_TRAVERSAL_VALIDATE);
while (true) {
lfsr_tinfo_t tinfo;
int err = lfsr_traversal_read(lfs, &traversal, &tinfo);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
// found an mdir?
if (tinfo.tag == LFSR_TAG_MDIR) {
// found an mroot?
if (tinfo.u.mdir.mid == -1) {
err = lfsr_mountmroot(lfs, &tinfo.u.mdir);
if (err) {
return err;
}
// keep track of the last mroot we see, this is the
// active mroot
lfs->mroot = tinfo.u.mdir;
} else {
// found a direct mdir? keep track of this
if (lfsr_mtree_isnull(lfs)) {
lfs->mtree = LFSR_MTREE_MPTR(
*lfsr_mdir_mptr(&tinfo.u.mdir),
lfsr_mweight(lfs));
}
}
// collect any gdeltas from this mdir
err = lfsr_fs_consumegdelta(lfs, &tinfo.u.mdir);
if (err) {
return err;
}
// check for any orphaned files
for (lfs_size_t rid = 0;
rid < (lfs_size_t)tinfo.u.mdir.rbyd.weight;
rid++) {
err = lfsr_mdir_lookup(lfs, &tinfo.u.mdir,
rid, LFSR_TAG_ORPHAN,
NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// found an orphaned file?
if (err != LFS_ERR_NOENT) {
LFS_DEBUG("Found orphaned file "
"%"PRId32".%"PRId32,
lfsr_mid_bid(lfs, tinfo.u.mdir.mid) >> lfs->mbits,
rid);
lfs->hasorphans = true;
}
}
// found an mtree inner-node?
} else if (tinfo.tag == LFSR_TAG_BRANCH) {
// found the root of the mtree? keep track of this
if (lfsr_mtree_isnull(lfs)) {
lfs->mtree.u.btree = tinfo.u.rbyd;
}
} else {
LFS_UNREACHABLE();
}
}
// once we've mounted and derived a pseudo-random seed, initialize our
// block allocator
//
// the purpose of this is to avoid bad wear patterns such as always
// allocating blocks near the beginning of disk after a power-loss
//
lfs->lookahead.start = lfs->seed % lfs->cfg->block_count;
// TODO should the consumegdelta above take gstate/gdelta as a parameter?
// keep track of the current gstate on disk
memcpy(lfs->grm_g, lfs->grm_d, LFSR_GRM_DSIZE);
// decode grm so we can report any removed files as missing
int err = lfsr_data_readgrm(lfs, &LFSR_DATA_BUF(lfs->grm_g, LFSR_GRM_DSIZE),
&lfs->grm);
if (err) {
// TODO switch to read-only?
return err;
}
if (lfsr_grm_hasrm(&lfs->grm)) {
// found pending grms? this should only happen if we lost power
if (lfsr_grm_count(&lfs->grm) == 2) {
LFS_DEBUG("Found pending grm "
"%"PRId32".%"PRId32" %"PRId32".%"PRId32,
lfsr_mid_bid(lfs, lfs->grm.rms[0]) >> lfs->mbits,
lfsr_mid_rid(lfs, lfs->grm.rms[0]),
lfsr_mid_bid(lfs, lfs->grm.rms[1]) >> lfs->mbits,
lfsr_mid_rid(lfs, lfs->grm.rms[1]));
} else if (lfsr_grm_count(&lfs->grm) == 1) {
LFS_DEBUG("Found pending grm %"PRId32".%"PRId32,
lfsr_mid_bid(lfs, lfs->grm.rms[0]) >> lfs->mbits,
lfsr_mid_rid(lfs, lfs->grm.rms[0]));
}
}
return 0;
}
static int lfsr_formatinited(lfs_t *lfs) {
for (int i = 0; i < 2; i++) {
// write superblock to both rbyds in the root mroot to hopefully
// avoid mounting an older filesystem on disk
lfsr_rbyd_t rbyd = {.blocks[0]=i, .eoff=0, .trunk=0};
int err = lfsr_bd_erase(lfs, rbyd.blocks[0]);
if (err) {
return err;
}
// note the initial revision count is arbitrary, but we use
// -1 and 0 here to help test that our sequence comparison
// works correctly
err = lfsr_rbyd_appendrev(lfs, &rbyd, (uint32_t)i - 1);
if (err) {
return err;
}
// our initial superblock contains a couple things:
// - our magic string, "littlefs"
// - any format-time configuration
// - the root's bookmark tag, which reserves did = 0 for the root
err = lfsr_rbyd_commit(lfs, &rbyd, -1, LFSR_ATTRS(
LFSR_ATTR(MAGIC, 0, BUF("littlefs", 8)),
LFSR_ATTR(VERSION, 0, IMM(((const uint8_t[2]){
LFS_DISK_VERSION_MAJOR,
LFS_DISK_VERSION_MINOR}), 2)),
LFSR_ATTR(RCOMPATFLAGS, 0, IMM((&(uint8_t){
LFSR_RCOMPAT_GRM}), 1)),
LFSR_ATTR(BLOCKSIZE, 0, LEB128(lfs->cfg->block_size-1)),
LFSR_ATTR(BLOCKCOUNT, 0, LEB128(lfs->cfg->block_count-1)),
LFSR_ATTR(NAMELIMIT, 0, LEB128(lfs->name_limit)),
LFSR_ATTR(SIZELIMIT, 0, LEB128(lfs->size_limit)),
LFSR_ATTR(BOOKMARK, +1, LEB128(0))));
if (err) {
return err;
}
}
// test that mount works with our formatted disk
int err = lfsr_mountinited(lfs);
if (err) {
return err;
}
return 0;
}
int lfsr_mount(lfs_t *lfs, const struct lfs_config *cfg) {
int err = lfs_init(lfs, cfg);
if (err) {
return err;
}
err = lfsr_mountinited(lfs);
if (err) {
// make sure we clean up on error
lfs_deinit(lfs);
return err;
}
// TODO this should use any configured values
LFS_DEBUG("Mounted littlefs v%"PRId32".%"PRId32" "
"%"PRId32"x%"PRId32" "
"0x{%"PRIx32",%"PRIx32"}.%"PRIx32" "
"w%"PRId32".%"PRId32,
LFS_DISK_VERSION_MAJOR,
LFS_DISK_VERSION_MINOR,
lfs->cfg->block_size,
lfs->cfg->block_count,
lfs->mroot.rbyd.blocks[0],
lfs->mroot.rbyd.blocks[1],
lfsr_rbyd_trunk(&lfs->mroot.rbyd),
lfsr_mtree_weight(lfs) / lfsr_mweight(lfs),
lfsr_mweight(lfs));
return 0;
}
int lfsr_unmount(lfs_t *lfs) {
return lfs_deinit(lfs);
}
int lfsr_format(lfs_t *lfs, const struct lfs_config *cfg) {
int err = lfs_init(lfs, cfg);
if (err) {
return err;
}
LFS_DEBUG("Formatting littlefs v%"PRId32".%"PRId32" "
"%"PRId32"x%"PRId32,
LFS_DISK_VERSION_MAJOR,
LFS_DISK_VERSION_MINOR,
lfs->cfg->block_size,
lfs->cfg->block_count);
err = lfsr_formatinited(lfs);
if (err) {
// make sure we clean up on error
lfs_deinit(lfs);
return err;
}
return lfs_deinit(lfs);
}
/// Block allocator ///
// Allocations should call this when all allocated blocks are committed to
// the filesystem, either in the mtree or in tracked mdirs. After a
// checkpoint, the block allocator may realloc any untracked blocks.
static void lfs_alloc_ckpoint(lfs_t *lfs) {
lfs->lookahead.ckpoint = lfs->cfg->block_count;
}
static inline void lfs_alloc_setinuse(lfs_t *lfs, lfs_block_t block) {
// translate to lookahead-relative
lfs_block_t rel = ((block + lfs->cfg->block_count) - lfs->lookahead.start)
% lfs->cfg->block_count;
if (rel < lfs->lookahead.size) {
// mark as in-use
lfs->lookahead.buffer[rel / 8] |= 1 << (rel % 8);
}
}
static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
while (true) {
// scan our lookahead buffer for free blocks
while (lfs->lookahead.next < lfs->lookahead.size) {
if (!(lfs->lookahead.buffer[lfs->lookahead.next / 8]
& (1 << (lfs->lookahead.next % 8)))) {
// found a free block
*block = (lfs->lookahead.start + lfs->lookahead.next)
% lfs->cfg->block_count;
// eagerly find next free block to maximize how many blocks
// lfs_alloc_ckpoint makes available for scanning
while (true) {
lfs->lookahead.next += 1;
lfs->lookahead.ckpoint -= 1;
if (lfs->lookahead.next >= lfs->lookahead.size
|| !(lfs->lookahead.buffer[lfs->lookahead.next / 8]
& (1 << (lfs->lookahead.next % 8)))) {
return 0;
}
}
}
lfs->lookahead.next += 1;
lfs->lookahead.ckpoint -= 1;
}
// In order to keep our block allocator from spinning forever when our
// filesystem is full, we mark points where there are no in-flight
// allocations with a checkpoint before starting a set of allocaitons.
//
// If we've looked at all blocks since the last checkpoint, we report
// the filesystem as out of storage.
//
if (lfs->lookahead.ckpoint <= 0) {
LFS_ERROR("No more free space 0x%"PRIx32,
(lfs->lookahead.start + lfs->lookahead.next)
% lfs->cfg->block_count);
return LFS_ERR_NOSPC;
}
// No blocks in our lookahead buffer, we need to scan the filesystem for
// unused blocks in the next lookahead window.
//
// note we limit the lookahead window to at most the amount of blocks
// checkpointed, this prevents the above math from underflowing
//
lfs->lookahead.start += lfs->lookahead.size;
lfs->lookahead.next = 0;
lfs->lookahead.size = lfs_min32(
8*lfs->cfg->lookahead_size,
lfs->lookahead.ckpoint);
memset(lfs->lookahead.buffer, 0, lfs->cfg->lookahead_size);
// traverse the filesystem, building up knowledge of what blocks are
// in use in our lookahead window
lfsr_traversal_t traversal = LFSR_TRAVERSAL(LFSR_TRAVERSAL_ALL);
while (true) {
lfsr_tinfo_t tinfo;
int err = lfsr_traversal_read(lfs, &traversal, &tinfo);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
// TODO add block pointers here?
// mark any blocks we see at in-use, including any btree/mdir blocks
if (tinfo.tag == LFSR_TAG_MDIR) {
lfs_alloc_setinuse(lfs, tinfo.u.mdir.rbyd.blocks[1]);
lfs_alloc_setinuse(lfs, tinfo.u.mdir.rbyd.blocks[0]);
} else if (tinfo.tag == LFSR_TAG_BRANCH) {
lfs_alloc_setinuse(lfs, tinfo.u.rbyd.blocks[0]);
} else if (tinfo.tag == LFSR_TAG_BLOCK) {
lfs_alloc_setinuse(lfs, tinfo.u.bptr.data.u.disk.block);
} else {
LFS_UNREACHABLE();
}
}
}
}
/// Other filesystem traversal things ///
lfs_ssize_t lfsr_fs_size(lfs_t *lfs) {
lfs_size_t count = 0;
lfsr_traversal_t traversal = LFSR_TRAVERSAL(LFSR_TRAVERSAL_ALL);
while (true) {
lfsr_tinfo_t tinfo;
int err = lfsr_traversal_read(lfs, &traversal, &tinfo);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
// TODO add block pointers here?
// count the number of blocks we see, yes this may result in duplicates
if (tinfo.tag == LFSR_TAG_MDIR) {
count += 2;
} else if (tinfo.tag == LFSR_TAG_BRANCH) {
count += 1;
} else if (tinfo.tag == LFSR_TAG_BLOCK) {
count += 1;
} else {
LFS_UNREACHABLE();
}
}
return count;
}
/// Prepare the filesystem for mutation ///
static int lfsr_fs_fixgrm(lfs_t *lfs) {
while (lfsr_grm_hasrm(&lfs->grm)) {
// find our mdir
lfsr_mdir_t mdir;
LFS_ASSERT(lfs->grm.rms[0] < lfs_smax32(
lfsr_mtree_weight(lfs),
lfsr_mweight(lfs)));
int err = lfsr_mtree_lookup(lfs, lfs->grm.rms[0],
&mdir);
if (err) {
return err;
}
// mark grm as taken care of
lfsr_grm_t grm = lfs->grm;
lfsr_grm_poprm(&grm);
// make sure to adjust any remaining grms
if (lfsr_mid_bid(lfs, grm.rms[0]) == lfsr_mid_bid(lfs, mdir.mid)
&& grm.rms[0] >= mdir.mid) {
LFS_ASSERT(grm.rms[0] != mdir.mid);
grm.rms[0] -= 1;
}
// remove the rid while also updating our grm
LFS_ASSERT(lfsr_mid_rid(lfs, lfs->grm.rms[0]) < mdir.rbyd.weight);
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
LFSR_ATTR(RM, -1, NULL()),
LFSR_ATTR(GRM, 0, GRM(&grm))));
}
return 0;
}
static int lfsr_fs_fixorphans(lfs_t *lfs) {
// traverse the filesystem and remove any orphaned files
//
// note this never takes longer than lfsr_mount
//
lfsr_mdir_t mdir;
int err = lfsr_mtree_lookup(lfs, 0, &mdir);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
while (true) {
// is this mid opened? skip
if (!lfsr_mid_isopened(lfs, mdir.mid)) {
// are we an orphaned file?
err = lfsr_mdir_lookup(lfs, &mdir, mdir.mid, LFSR_TAG_ORPHAN,
NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
// remove orphaned file
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
LFSR_ATTR(RM, -1, NULL())));
if (err) {
return err;
}
// seek in case our mdir was dropped
err = lfsr_mtree_seek(lfs, &mdir, 0);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
continue;
}
}
// lookup next entry
err = lfsr_mtree_seek(lfs, &mdir, 1);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
}
lfs->hasorphans = false;
return 0;
}
static int lfsr_fs_preparemutation(lfs_t *lfs) {
// checkpoint the allocator
lfs_alloc_ckpoint(lfs);
// fix pending grms
bool pl = false;
if (lfsr_grm_hasrm(&lfs->grm)) {
if (lfsr_grm_count(&lfs->grm) == 2) {
LFS_DEBUG("Fixing grm "
"%"PRId32".%"PRId32" %"PRId32".%"PRId32"...",
lfsr_mid_bid(lfs, lfs->grm.rms[0]) >> lfs->mbits,
lfsr_mid_rid(lfs, lfs->grm.rms[0]),
lfsr_mid_bid(lfs, lfs->grm.rms[1]) >> lfs->mbits,
lfsr_mid_rid(lfs, lfs->grm.rms[1]));
} else {
LFS_DEBUG("Fixing grm %"PRId32".%"PRId32,
lfsr_mid_bid(lfs, lfs->grm.rms[0]) >> lfs->mbits,
lfsr_mid_rid(lfs, lfs->grm.rms[0]));
}
pl = true;
int err = lfsr_fs_fixgrm(lfs);
if (err) {
return err;
}
// checkpoint the allocator again since fixgrm completed
// some work
lfs_alloc_ckpoint(lfs);
}
// fix orphaned files
//
// this must happen after fixgrm, since removing orphaned files risks
// outdating the grm
//
if (lfs->hasorphans) {
LFS_DEBUG("Fixing orphans...");
pl = true;
int err = lfsr_fs_fixorphans(lfs);
if (err) {
return err;
}
// checkpoint the allocator again since fixorphans completed
// some work
lfs_alloc_ckpoint(lfs);
}
if (pl) {
LFS_DEBUG("littlefs is now consistent");
}
return 0;
}
/// Directory operations ///
// needed in lfsr_mkdir
static inline bool lfsr_f_iszombie(uint32_t flags);
int lfsr_mkdir(lfs_t *lfs, const char *path) {
// prepare our filesystem for writing
int err = lfsr_fs_preparemutation(lfs);
if (err) {
return err;
}
// lookup our parent
lfsr_mdir_t mdir;
lfsr_tag_t tag;
lfsr_did_t did;
const char *name;
lfs_size_t name_size;
err = lfsr_mtree_pathlookup(lfs, path,
&mdir, &tag,
&did, &name, &name_size);
if (err && err != LFS_ERR_EXIST) {
return err;
}
// already exists? note orphans don't really exist
bool exists = (err == LFS_ERR_EXIST);
if (exists && tag != LFSR_TAG_ORPHAN) {
return LFS_ERR_EXIST;
}
// check that name fits
if (name_size > lfs->name_limit) {
return LFS_ERR_NAMETOOLONG;
}
// Our directory needs an arbitrary directory-rid. To find one with
// hopefully few collisions, we use a hash of the full path using our CRC,
// since we have it handy.
//
// We also truncate to make better use of our leb128 encoding. This is
// relatively arbitrary, but if we truncate too much we risk increasing
// the number of collisions, so we want to aim for ~2x the number dids
// in the system. We don't actually know the number of dids in the system,
// but we can use a heuristic based on the maximum possible number of
// directories in the current mtree assuming our block size.
//
// - Each directory needs 1 name tag, 1 did tag, and 1 bookmark
// - Each tag needs ~2 alts+null with our current compaction strategy
// - Each tag/alt encodes to a minimum of 4 bytes
// - We can also assume ~1/2 block utilization due to our split threshold
//
// This gives us ~3*4*4*2 or ~96 bytes per directory at minimum.
// Multiplying by 2 and rounding down to the nearest power of 2 for cheaper
// division gives us a heuristic of ~block_size/32 directories per mdir.
//
// This is a nice number because for common NOR flash geometry,
// 4096/32 = 128, so a filesystem with a single mdir encodes dids in a
// single byte.
//
// Note we also need to be careful to catch integer overflow.
//
lfsr_did_t dmask = (1 << lfs_min32(
lfs_nlog2(lfsr_mtree_weight(lfs))
+ lfs_nlog2(lfs->cfg->block_size/32),
32)) - 1;
lfsr_did_t did_ = lfs_crc32c(0, path, strlen(path)) & dmask;
// Check if we have a collision. If we do, search for the next
// available did
while (true) {
err = lfsr_mtree_namelookup(lfs, did_, NULL, 0,
&mdir, NULL, NULL);
if (err) {
if (err == LFS_ERR_NOENT) {
break;
}
return err;
}
// try the next did
did_ = (did_ + 1) & dmask;
}
// found a good did, now to commit to the mtree
//
// A problem: we need to create both:
// 1. the metadata entry
// 2. the bookmark entry
//
// To do this atomically, we first create the bookmark entry with a grm
// to delete-self in case of powerloss, then create the metadata entry
// while atomically cancelling the grm.
// commit our bookmark and a grm to self-remove in case of powerloss
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
LFSR_ATTR(BOOKMARK, +1, LEB128(did_)),
LFSR_ATTR(GRM, 0, GRM(&((lfsr_grm_t){{mdir.mid+1, -1}})))));
if (err) {
return err;
}
// committing our bookmark may have changed the mid of our metadata entry,
// we need to look it up again, we can at least avoid the full path walk
err = lfsr_mtree_namelookup(lfs, did, name, name_size,
&mdir, NULL, NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
LFS_ASSERT((exists) ? !err : err == LFS_ERR_NOENT);
// commit our new directory into our parent, zeroing the grm in the
// process
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
LFSR_ATTR(
SUPMASK(DIR), (!exists) ? +1 : 0, CAT(
LFSR_DATA_LEB128(did),
LFSR_DATA_BUF(name, name_size))),
LFSR_ATTR(DID, 0, LEB128(did_)),
LFSR_ATTR(GRM, 0, GRM(&((lfsr_grm_t){{-1, -1}})))));
if (err) {
return err;
}
return 0;
}
int lfsr_remove(lfs_t *lfs, const char *path) {
// prepare our filesystem for writing
int err = lfsr_fs_preparemutation(lfs);
if (err) {
return err;
}
// lookup our entry
lfsr_mdir_t mdir;
lfsr_tag_t tag;
lfsr_did_t did;
const char *name;
lfs_size_t name_size;
err = lfsr_mtree_pathlookup(lfs, path,
&mdir, &tag,
&did, &name, &name_size);
if (err && err != LFS_ERR_EXIST) {
return err;
}
// doesn't exist? note orphans don't really exist
if (!err || tag == LFSR_TAG_ORPHAN) {
return LFS_ERR_NOENT;
}
// if we're removing a directory, we need to also remove the
// bookmark entry
lfsr_grm_t grm = lfs->grm;
if (tag == LFSR_TAG_DIR) {
// first lets figure out the did
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &mdir, mdir.mid, LFSR_TAG_DID,
&data);
if (err) {
return err;
}
lfsr_did_t did;
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&did);
if (err) {
return err;
}
// then lookup the bookmark entry
lfsr_mdir_t bookmark_mdir;
err = lfsr_mtree_namelookup(lfs, did, NULL, 0,
&bookmark_mdir, NULL, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// create a grm to remove the bookmark entry
lfsr_grm_pushrm(&grm, bookmark_mdir.mid);
// check that the directory is empty
err = lfsr_mtree_seek(lfs, &bookmark_mdir, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
lfsr_tag_t bookmark_tag;
err = lfsr_mdir_sublookup(lfs, &bookmark_mdir,
bookmark_mdir.mid, LFSR_TAG_NAME,
&bookmark_tag, NULL);
if (err) {
return err;
}
if (bookmark_tag != LFSR_TAG_BOOKMARK) {
return LFS_ERR_NOTEMPTY;
}
}
}
// are we removing an opened file?
bool zombie = lfsr_mid_isopened(lfs, mdir.mid);
// adjust grm rid if grm is on the same mdir as our dir
if (!zombie
&& lfsr_mid_bid(lfs, grm.rms[0]) == lfsr_mid_bid(lfs, mdir.mid)
&& grm.rms[0] > mdir.mid) {
grm.rms[0] -= 1;
}
// remove the metadata entry
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
// create an orphan if zombied
//
// we use a create+delete here to also clear any attrs
// and trim the entry size
(zombie)
? LFSR_ATTR(SUPMASK(ORPHAN), 0, CAT(
LFSR_DATA_LEB128(did),
LFSR_DATA_BUF(name, name_size)))
: LFSR_ATTR(RM, -1, NULL()),
LFSR_ATTR(GRM, 0, GRM(&grm))));
if (err) {
return err;
}
// lfsr_mdir_commit implicitly marks removed files as zombied, but
// we also need to mark them as uncreate to indicate that the mid
// needs to be cleaned up on close
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
if (opened->type == LFS_TYPE_REG
&& opened->mdir.mid == mdir.mid) {
opened->flags |= LFS_F_ORPHAN;
}
}
// if we were a directory, we need to clean up, fortunately we can leave
// this up to lfsr_fs_fixgrm
return lfsr_fs_fixgrm(lfs);
}
int lfsr_rename(lfs_t *lfs, const char *old_path, const char *new_path) {
// prepare our filesystem for writing
int err = lfsr_fs_preparemutation(lfs);
if (err) {
return err;
}
// lookup old entry
lfsr_mdir_t old_mdir;
lfsr_tag_t old_tag;
err = lfsr_mtree_pathlookup(lfs, old_path,
&old_mdir, &old_tag,
NULL, NULL, NULL);
if (err && err != LFS_ERR_EXIST) {
return err;
}
// doesn't exist? note orphans don't really exist
if (!err || old_tag == LFSR_TAG_ORPHAN) {
return LFS_ERR_NOENT;
}
// mark old entry for removal with a grm
lfsr_grm_t grm = lfs->grm;
lfsr_grm_pushrm(&grm, old_mdir.mid);
// lookup new entry
lfsr_mdir_t new_mdir;
lfsr_tag_t new_tag;
lfsr_did_t new_did;
const char *new_name;
lfs_size_t new_name_size;
err = lfsr_mtree_pathlookup(lfs, new_path,
&new_mdir, &new_tag,
&new_did, &new_name, &new_name_size);
if (err && err != LFS_ERR_EXIST) {
return err;
}
// already exists?
bool exists = (err == LFS_ERR_EXIST);
// there are a few cases we need to watch out for
if (!exists) {
// check that name fits
if (new_name_size > lfs->name_limit) {
return LFS_ERR_NAMETOOLONG;
}
// adjust old rid if grm is on the same mdir as new rid
if (lfsr_mid_bid(lfs, grm.rms[0]) == lfsr_mid_bid(lfs, new_mdir.mid)
&& grm.rms[0] > new_mdir.mid) {
grm.rms[0] += 1;
}
} else {
// renaming different types is an error
//
// unless we found a orphan, these don't really exist
if (old_tag != new_tag && new_tag != LFSR_TAG_ORPHAN) {
return (new_tag == LFSR_TAG_DIR)
? LFS_ERR_ISDIR
: LFS_ERR_NOTDIR;
}
// TODO is it? is this check necessary?
// renaming to ourself is a noop
if (old_mdir.mid == new_mdir.mid) {
return 0;
}
// if our destination is a directory, we will be implicitly removing
// the directory, we need to create a grm for this
if (new_tag == LFSR_TAG_DIR) {
// TODO deduplicate the isempty check with lfsr_remove?
// first lets figure out the did
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &new_mdir,
new_mdir.mid, LFSR_TAG_DID,
&data);
if (err) {
return err;
}
lfsr_did_t did;
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&did);
if (err) {
return err;
}
// then lookup the bookmark entry
lfsr_mdir_t bookmark_mdir;
err = lfsr_mtree_namelookup(lfs, did, NULL, 0,
&bookmark_mdir, NULL, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// create a grm to remove the bookmark entry
lfsr_grm_pushrm(&grm, bookmark_mdir.mid);
// check that the directory is empty
err = lfsr_mtree_seek(lfs, &bookmark_mdir, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
lfsr_tag_t bookmark_tag;
err = lfsr_mdir_sublookup(lfs, &bookmark_mdir,
bookmark_mdir.mid, LFSR_TAG_NAME,
&bookmark_tag, NULL);
if (err) {
return err;
}
if (bookmark_tag != LFSR_TAG_BOOKMARK) {
return LFS_ERR_NOTEMPTY;
}
}
}
}
// rename our entry, copying all tags associated with the old rid to the
// new rid, while also marking the old rid for removal
err = lfsr_mdir_commit(lfs, &new_mdir, LFSR_ATTRS(
LFSR_ATTR(
SUPMASK(TAG(old_tag)), (!exists) ? +1 : 0, CAT(
LFSR_DATA_LEB128(new_did),
LFSR_DATA_BUF(new_name, new_name_size))),
LFSR_ATTR(MOVE, 0, MOVE(&old_mdir)),
LFSR_ATTR(GRM, 0, GRM(&grm))));
if (err) {
return err;
}
// update moved files with the new mdir
for (lfsr_opened_t *opened = lfs->opened;
opened;
opened = opened->next) {
if (opened->type == LFS_TYPE_REG
&& lfsr_grm_isrm(&lfs->grm, opened->mdir.mid)) {
opened->mdir = new_mdir;
}
}
// we need to clean up any pending grms, fortunately we can leave
// this up to lfsr_fs_fixgrm
return lfsr_fs_fixgrm(lfs);
}
// this just populates the info struct based on what we found
static int lfsr_stat_(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_tag_t tag, lfsr_data_t name,
struct lfs_info *info) {
// get file type from the tag
info->type = lfsr_tag_subtype(tag);
// read the file name
LFS_ASSERT(lfsr_data_size(&name) <= LFS_NAME_MAX);
lfs_ssize_t name_size = lfsr_data_read(lfs, &name,
info->name, LFS_NAME_MAX);
if (name_size < 0) {
return name_size;
}
info->name[name_size] = '\0';
// get file size if we're a regular file, this gets a bit messy
// because of the different file representations
info->size = 0;
if (tag == LFSR_TAG_REG) {
// inlined?
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_mdir_lookupnext(lfs, mdir, mdir->mid, LFSR_TAG_DATA,
&tag, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// may be a sprout (simple inlined data)
if (err != LFS_ERR_NOENT && tag == LFSR_TAG_DATA) {
info->size = lfsr_data_size(&data);
// or a block/bshrub/btree, size is always first field here
} else if (err != LFS_ERR_NOENT
&& (tag == LFSR_TAG_BLOCK
|| tag == LFSR_TAG_BSHRUB
|| tag == LFSR_TAG_BTREE)) {
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&info->size);
if (err) {
return err;
}
}
}
return 0;
}
int lfsr_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
// lookup our entry
lfsr_mdir_t mdir;
lfsr_tag_t tag;
const char *name;
lfs_size_t name_size;
int err = lfsr_mtree_pathlookup(lfs, path,
&mdir, &tag,
NULL, &name, &name_size);
if (err && err != LFS_ERR_EXIST && err != LFS_ERR_INVAL) {
return err;
}
// doesn't exist? note orphans don't really exist
if (!err || tag == LFSR_TAG_ORPHAN) {
return LFS_ERR_NOENT;
}
// special case for root
if (err == LFS_ERR_INVAL) {
strcpy(info->name, "/");
info->type = LFS_TYPE_DIR;
info->size = 0;
return 0;
}
// fill out our info struct
return lfsr_stat_(lfs, &mdir,
tag, LFSR_DATA_BUF(name, name_size),
info);
}
int lfsr_dir_open(lfs_t *lfs, lfsr_dir_t *dir, const char *path) {
// setup dir state
dir->p.type = LFS_TYPE_DIR;
dir->p.flags = 0;
dir->b.type = LFS_TYPE_BOOKMARK;
dir->b.flags = 0;
// lookup our directory
lfsr_mdir_t mdir;
lfsr_tag_t tag;
int err = lfsr_mtree_pathlookup(lfs, path,
&mdir, &tag,
NULL, NULL, NULL);
if (err && err != LFS_ERR_EXIST && err != LFS_ERR_INVAL) {
return err;
}
// doesn't exist? note orphans don't really exist
if (!err || tag == LFSR_TAG_ORPHAN) {
return LFS_ERR_NOENT;
}
// read our did from the mdir, unless we're root
if (err == LFS_ERR_INVAL) {
dir->did = 0;
} else {
// not a directory?
if (tag != LFSR_TAG_DIR) {
return LFS_ERR_NOTDIR;
}
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &mdir, mdir.mid, LFSR_TAG_DID,
&data);
if (err) {
return err;
}
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&dir->did);
if (err) {
return err;
}
}
// lookup our bookmark in the mtree
err = lfsr_mtree_namelookup(lfs, dir->did, NULL, 0,
&dir->b.mdir, NULL, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// let rewind initialize the pos state
err = lfsr_dir_rewind(lfs, dir);
if (err) {
return err;
}
// add to tracked mdirs
lfsr_addopened(lfs, &dir->p);
lfsr_addopened(lfs, &dir->b);
return 0;
}
int lfsr_dir_close(lfs_t *lfs, lfsr_dir_t *dir) {
// remove from tracked mdirs
lfsr_removeopened(lfs, &dir->p);
lfsr_removeopened(lfs, &dir->b);
return 0;
}
int lfsr_dir_read(lfs_t *lfs, lfsr_dir_t *dir, struct lfs_info *info) {
// was our dir removed?
if (lfsr_f_iszombie(dir->b.flags)) {
return LFS_ERR_NOENT;
}
// handle dots specially
if (dir->pos == 0) {
strcpy(info->name, ".");
info->type = LFS_TYPE_DIR;
info->size = 0;
dir->pos += 1;
return 0;
} else if (dir->pos == 1) {
strcpy(info->name, "..");
info->type = LFS_TYPE_DIR;
info->size = 0;
dir->pos += 1;
return 0;
}
// seek in case our mdir was dropped
int err = lfsr_mtree_seek(lfs, &dir->p.mdir, 0);
if (err) {
return err;
}
while (true) {
// lookup the next name tag
lfsr_tag_t tag;
lfsr_data_t data;
err = lfsr_mdir_sublookup(lfs, &dir->p.mdir,
dir->p.mdir.mid, LFSR_TAG_NAME,
&tag, &data);
if (err) {
return err;
}
// get the did
lfsr_did_t did;
err = lfsr_data_readleb128(lfs, &data, (int32_t*)&did);
if (err) {
return err;
}
// did mismatch? this terminates the dir read
if (did != dir->did) {
return LFS_ERR_NOENT;
}
// skip orphans, we pretend these don't exist
if (tag != LFSR_TAG_ORPHAN) {
// fill out our info struct
err = lfsr_stat_(lfs, &dir->p.mdir, tag, data,
info);
if (err) {
return err;
}
}
// eagerly look up the next entry
err = lfsr_mtree_seek(lfs, &dir->p.mdir, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
dir->pos += 1;
if (tag != LFSR_TAG_ORPHAN) {
return 0;
}
}
}
int lfsr_dir_seek(lfs_t *lfs, lfsr_dir_t *dir, lfs_soff_t off) {
// do nothing if removed
if (lfsr_f_iszombie(dir->b.flags)) {
return 0;
}
// first rewind
int err = lfsr_dir_rewind(lfs, dir);
if (err) {
return err;
}
// then seek to the requested offset, we leave it up to lfsr_mtree_seek
// to make this efficient
//
// note the -2 to adjust for dot entries
if (off > 2) {
err = lfsr_mtree_seek(lfs, &dir->p.mdir, off - 2);
if (err && err != LFS_ERR_NOENT) {
return err;
}
}
dir->pos = off;
return 0;
}
lfs_soff_t lfsr_dir_tell(lfs_t *lfs, lfsr_dir_t *dir) {
(void)lfs;
return dir->pos;
}
int lfsr_dir_rewind(lfs_t *lfs, lfsr_dir_t *dir) {
// do nothing if removed
if (lfsr_f_iszombie(dir->b.flags)) {
return 0;
}
// reset pos
dir->pos = 0;
// copy bookmark mdir and eagerly lookup the next entry
dir->p.mdir = dir->b.mdir;
int err = lfsr_mtree_seek(lfs, &dir->p.mdir, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
return 0;
}
/// File operations ///
#define LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR 0x80000000
#define LFSR_BSHRUB_BNULL() \
((lfsr_bshrub_t){.u.size=(LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR | 0)})
static inline bool lfsr_bshrub_isbnull(const lfsr_bshrub_t *bshrub) {
return (lfs_size_t)bshrub->u.size
== (LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR | 0);
}
static inline bool lfsr_bshrub_isbsprout(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub) {
return (lfs_size_t)bshrub->u.size
> (LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR | 0)
&& bshrub->u.bsprout.u.disk.block == mdir->rbyd.blocks[0];
}
static inline bool lfsr_bshrub_isbptr(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub) {
return (lfs_size_t)bshrub->u.size
> (LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR | 0)
&& bshrub->u.bsprout.u.disk.block != mdir->rbyd.blocks[0];
}
static inline bool lfsr_bshrub_isbshrub(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub) {
return !(bshrub->u.size & LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR)
&& bshrub->u.bshrub.blocks[0] == mdir->rbyd.blocks[0];
}
static inline bool lfsr_bshrub_isbtree(
const lfsr_mdir_t *mdir, const lfsr_bshrub_t *bshrub) {
return !(bshrub->u.size & LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR)
&& bshrub->u.bshrub.blocks[0] != mdir->rbyd.blocks[0];
}
static inline bool lfsr_bshrub_isbnullorbsproutorbptr(
const lfsr_bshrub_t *bshrub) {
return bshrub->u.size & LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR;
}
static inline bool lfsr_bshrub_isbshruborbtree(
const lfsr_bshrub_t *bshrub) {
return !(bshrub->u.size & LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR);
}
// the on-disk size/weight lines up to the same word across all unions
static inline lfs_off_t lfsr_bshrub_size(const lfsr_bshrub_t *bshrub) {
return bshrub->u.size & ~LFSR_BSHRUB_ISBNULLORBSPROUTORBPTR;
}
// flag things
static inline bool lfsr_o_isrdonly(uint32_t flags) {
return (flags & 3) == LFS_O_RDONLY;
}
static inline bool lfsr_o_iswronly(uint32_t flags) {
return (flags & 3) == LFS_O_WRONLY;
}
static inline bool lfsr_o_iscreat(uint32_t flags) {
return flags & LFS_O_CREAT;
}
static inline bool lfsr_o_isexcl(uint32_t flags) {
return flags & LFS_O_EXCL;
}
static inline bool lfsr_o_istrunc(uint32_t flags) {
return flags & LFS_O_TRUNC;
}
static inline bool lfsr_o_isappend(uint32_t flags) {
return flags & LFS_O_APPEND;
}
static inline bool lfsr_o_issync(uint32_t flags) {
return flags & LFS_O_SYNC;
}
static inline bool lfsr_o_isdesync(uint32_t flags) {
return flags & LFS_O_DESYNC;
}
static inline bool lfsr_o_isflush(uint32_t flags) {
return flags & LFS_O_FLUSH;
}
static inline bool lfsr_f_isunflush(uint32_t flags) {
return flags & LFS_F_UNFLUSH;
}
static inline bool lfsr_f_isunsync(uint32_t flags) {
return flags & LFS_F_UNSYNC;
}
static inline bool lfsr_f_isorphan(uint32_t flags) {
return flags & LFS_F_ORPHAN;
}
static inline bool lfsr_f_iszombie(uint32_t flags) {
return flags & LFS_F_ZOMBIE;
}
static inline lfs_off_t lfsr_file_size_(const lfsr_file_t *file) {
return lfs_max32(
file->buffer_pos + file->buffer_size,
lfsr_bshrub_size(&file->bshrub));
}
// file operations
// needed in lfsr_file_opencfg
static lfs_ssize_t lfsr_bshrub_read(lfs_t *lfs, const lfsr_file_t *file,
lfs_off_t pos, uint8_t *buffer, lfs_size_t size);
int lfsr_file_opencfg(lfs_t *lfs, lfsr_file_t *file,
const char *path, uint32_t flags,
const struct lfs_file_config *cfg) {
// don't allow the forbidden mode!
LFS_ASSERT((flags & 3) != 3);
// these flags require a writable file
LFS_ASSERT(!lfsr_o_isrdonly(flags) || !lfsr_o_iscreat(flags));
LFS_ASSERT(!lfsr_o_isrdonly(flags) || !lfsr_o_isexcl(flags));
LFS_ASSERT(!lfsr_o_isrdonly(flags) || !lfsr_o_istrunc(flags));
LFS_ASSERT(!lfsr_o_isrdonly(flags) || !lfsr_o_isappend(flags));
// these flags are internal and shouldn't be provided by the user
LFS_ASSERT(!lfsr_f_isunflush(flags));
LFS_ASSERT(!lfsr_f_isunsync(flags));
LFS_ASSERT(!lfsr_f_isorphan(flags));
if (!lfsr_o_isrdonly(flags)) {
// prepare our filesystem for writing
int err = lfsr_fs_preparemutation(lfs);
if (err) {
return err;
}
}
// setup file state
file->m.type = LFS_TYPE_REG;
file->m.flags = flags;
file->cfg = cfg;
file->pos = 0;
// default data state
file->bshrub = LFSR_BSHRUB_BNULL();
// lookup our parent
lfsr_tag_t tag;
lfsr_did_t did;
const char *name;
lfs_size_t name_size;
int err = lfsr_mtree_pathlookup(lfs, path,
&file->m.mdir, &tag,
&did, &name, &name_size);
if (err && err != LFS_ERR_EXIST) {
return err;
}
// creating a new entry?
if (!err || tag == LFSR_TAG_ORPHAN) {
if (!lfsr_o_iscreat(flags)) {
return LFS_ERR_NOENT;
}
LFS_ASSERT(!lfsr_o_isrdonly(flags));
// check that name fits
if (name_size > lfs->name_limit) {
return LFS_ERR_NAMETOOLONG;
}
// create an orphan entry if we don't have one, this reserves the
// mid until first sync
if (!err) {
err = lfsr_mdir_commit(lfs, &file->m.mdir, LFSR_ATTRS(
LFSR_ATTR(
ORPHAN, +1, CAT(
LFSR_DATA_LEB128(did),
LFSR_DATA_BUF(name, name_size)))));
if (err) {
return err;
}
}
// mark as unsync and uncreat, we need to convert to reg file
// first sync
file->m.flags |= LFS_F_UNSYNC | LFS_F_ORPHAN;
} else {
if (lfsr_o_isexcl(flags)) {
// oh, we really wanted to create a new entry
return LFS_ERR_EXIST;
}
// wrong type?
if (tag != LFSR_TAG_REG) {
return LFS_ERR_ISDIR;
}
// if we're truncating don't bother to read any state, we're
// just going to truncate after all
if (!lfsr_o_istrunc(flags)) {
// read any inlined state
lfsr_tag_t tag;
lfsr_data_t data;
err = lfsr_mdir_lookupnext(lfs, &file->m.mdir,
file->m.mdir.mid, LFSR_TAG_DATA,
&tag, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// TODO the above clobbers data on failure, which is why we can't
// lookup into the inlined data directly. Should this be avoided?
// Should we at least be consistent in this codebase?
// may be a sprout (simple inlined data)
if (err != LFS_ERR_NOENT && tag == LFSR_TAG_DATA) {
file->bshrub.u.bsprout = data;
// or a direct block
} else if (err != LFS_ERR_NOENT && tag == LFSR_TAG_BLOCK) {
err = lfsr_data_readbptr(lfs, &data,
&file->bshrub.u.bptr);
if (err) {
return err;
}
// or a bshrub (inlined btree)
} else if (err != LFS_ERR_NOENT && tag == LFSR_TAG_BSHRUB) {
err = lfsr_data_readshrub(lfs, &data, &file->m.mdir,
&file->bshrub.u.bshrub);
if (err) {
return err;
}
// or a btree
} else if (err != LFS_ERR_NOENT && tag == LFSR_TAG_BTREE) {
err = lfsr_data_readbtree(lfs, &data, &file->bshrub.u.btree);
if (err) {
return err;
}
}
}
}
// allocate buffer if necessary
if (file->cfg->buffer) {
file->buffer = file->cfg->buffer;
} else {
file->buffer = lfs_malloc(lfs->cfg->cache_size);
if (!file->buffer) {
return LFS_ERR_NOMEM;
}
}
file->buffer_pos = 0;
file->buffer_size = 0;
// if our file is small, try to keep the whole thing in our buffer
if (lfsr_bshrub_size(&file->bshrub) <= lfs->cfg->cache_size
&& lfsr_bshrub_size(&file->bshrub) <= lfs->cfg->inline_size
&& lfsr_bshrub_size(&file->bshrub) <= lfs->cfg->fragment_size) {
lfs_ssize_t d = lfsr_bshrub_read(lfs, file,
0, file->buffer, lfsr_bshrub_size(&file->bshrub));
if (d < 0) {
err = d;
goto failed;
}
// small files remain perpetually unflushed
file->m.flags |= LFS_F_UNFLUSH;
file->buffer_pos = 0;
file->buffer_size = lfsr_bshrub_size(&file->bshrub);
file->bshrub = LFSR_BSHRUB_BNULL();
}
// add to tracked mdirs
lfsr_addopened(lfs, &file->m);
return 0;
failed:;
// clean up memory
if (!file->cfg->buffer) {
lfs_free(file->buffer);
}
return err;
}
// default file config
static const struct lfs_file_config lfsr_file_defaults = {0};
int lfsr_file_open(lfs_t *lfs, lfsr_file_t *file,
const char *path, uint32_t flags) {
return lfsr_file_opencfg(lfs, file, path, flags, &lfsr_file_defaults);
}
// needed in lfsr_file_close
int lfsr_file_sync(lfs_t *lfs, lfsr_file_t *file);
int lfsr_file_close(lfs_t *lfs, lfsr_file_t *file) {
// don't call lfsr_file_sync if we're readonly or desynced
int err = 0;
if (!lfsr_o_isrdonly(file->m.flags)
&& !lfsr_o_isdesync(file->m.flags)) {
err = lfsr_file_sync(lfs, file);
}
// remove from tracked mdirs
lfsr_removeopened(lfs, &file->m);
// clean up memory
if (!file->cfg->buffer) {
lfs_free(file->buffer);
}
// are we orphaning a file?
//
// make sure we check _after_ removing ourselves
if (lfsr_f_isorphan(file->m.flags)
&& !lfsr_mid_isopened(lfs, file->m.mdir.mid)) {
// this gets a bit tricky, since we're not able to write to the
// filesystem if we're rdonly or desynced, fortunately we have
// a few tricks
// first try to push onto our grm queue
if (lfsr_grm_count(&lfs->grm) < 2) {
lfsr_grm_pushrm(&lfs->grm, file->m.mdir.mid);
// fallback to just marking the filesystem as orphaned
} else {
lfs->hasorphans = true;
}
}
return err;
}
// low-level file operations
// find a tight upper bound on the _full_ bshrub size, this includes
// any on-disk bshrubs, and all pending bshrubs
static lfs_ssize_t lfsr_bshrub_estimate(lfs_t *lfs, const lfsr_file_t *file) {
lfs_size_t estimate = 0;
// include all unique sprouts/shrubs related to our file,
// including the on-disk sprout/shrub
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_mdir_lookupnext(lfs, &file->m.mdir,
file->m.mdir.mid, LFSR_TAG_DATA,
&tag, &data);
if (err && err != LFS_ERR_NOENT) {
LFS_ASSERT(err < 0);
return err;
}
if (err != LFS_ERR_NOENT && tag == LFSR_TAG_DATA) {
lfs_ssize_t dsize = lfsr_sprout_estimate(lfs, &data);
if (dsize < 0) {
return dsize;
}
estimate += dsize;
} else if (err != LFS_ERR_NOENT && tag == LFSR_TAG_BSHRUB) {
lfsr_shrub_t shrub;
err = lfsr_data_readshrub(lfs, &data, &file->m.mdir,
&shrub);
if (err) {
LFS_ASSERT(err < 0);
return err;
}
lfs_ssize_t dsize = lfsr_shrub_estimate(lfs, &shrub);
if (dsize < 0) {
return dsize;
}
estimate += dsize;
}
// this includes our current shrub
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& file_->m.mdir.mid == file->m.mdir.mid) {
if (lfsr_bshrub_isbsprout(&file_->m.mdir, &file_->bshrub)) {
lfs_ssize_t dsize = lfsr_sprout_estimate(lfs,
&file_->bshrub.u.bsprout);
if (dsize < 0) {
return dsize;
}
estimate += dsize;
} else if (lfsr_bshrub_isbshrub(&file_->m.mdir, &file_->bshrub)) {
lfs_ssize_t dsize = lfsr_shrub_estimate(lfs,
&file_->bshrub.u.bshrub);
if (dsize < 0) {
return dsize;
}
estimate += dsize;
}
}
}
return estimate;
}
static int lfsr_bshrub_lookupnext(lfs_t *lfs, const lfsr_file_t *file,
lfs_off_t pos,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bid_t *weight_,
lfsr_bptr_t *bptr_, lfsr_ecksum_t *becksum_) {
if (pos >= lfsr_bshrub_size(&file->bshrub)) {
return LFS_ERR_NOENT;
}
// the above size check should make this impossible
LFS_ASSERT(!lfsr_bshrub_isbnull(&file->bshrub));
// inlined sprout?
if (lfsr_bshrub_isbsprout(&file->m.mdir, &file->bshrub)) {
if (bid_) {
*bid_ = lfsr_data_size(&file->bshrub.u.bsprout)-1;
}
if (tag_) {
*tag_ = LFSR_TAG_DATA;
}
if (weight_) {
*weight_ = lfsr_data_size(&file->bshrub.u.bsprout);
}
if (bptr_) {
bptr_->data = file->bshrub.u.bsprout;
}
if (becksum_) {
becksum_->size = -1;
}
return 0;
// block pointer?
} else if (lfsr_bshrub_isbptr(&file->m.mdir, &file->bshrub)) {
if (bid_) {
*bid_ = lfsr_data_size(&file->bshrub.u.bptr.data)-1;
}
if (tag_) {
*tag_ = LFSR_TAG_BLOCK;
}
if (weight_) {
*weight_ = lfsr_data_size(&file->bshrub.u.bptr.data);
}
if (bptr_) {
*bptr_ = file->bshrub.u.bptr;
}
if (becksum_) {
becksum_->size = -1;
}
return 0;
// bshrub/btree?
} else if (lfsr_bshrub_isbshruborbtree(&file->bshrub)) {
lfsr_bid_t bid;
lfsr_rbyd_t rbyd;
lfsr_srid_t rid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_data_t data;
int err = lfsr_btree_lookupnext_(lfs, &file->bshrub.u.btree, pos,
&bid, &rbyd, &rid, &tag, &weight, &data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
LFS_ASSERT(tag == LFSR_TAG_DATA
|| tag == LFSR_TAG_BLOCK);
if (bid_) {
*bid_ = bid;
}
if (tag_) {
*tag_ = tag;
}
if (weight_) {
*weight_ = weight;
}
if (bptr_) {
// decode bptrs
if (tag == LFSR_TAG_DATA) {
bptr_->data = data;
} else {
err = lfsr_data_readbptr(lfs, &data, bptr_);
if (err) {
return err;
}
}
LFS_ASSERT(lfsr_data_size(&bptr_->data) <= weight);
}
if (becksum_) {
// need an extra lookup to find becksums
err = lfsr_rbyd_lookup(lfs, &rbyd, rid, LFSR_TAG_BECKSUM,
&data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
becksum_->size = -1;
} else {
err = lfsr_data_readecksum(lfs, &data, becksum_);
if (err) {
return err;
}
}
}
return 0;
} else {
LFS_UNREACHABLE();
}
}
static int lfsr_bshrub_traverse(lfs_t *lfs, const lfsr_file_t *file,
lfsr_btraversal_t *btraversal,
lfsr_bid_t *bid_, lfsr_tinfo_t *tinfo_) {
// bnull/bsprout do nothing
if (lfsr_bshrub_isbnull(&file->bshrub)
|| lfsr_bshrub_isbsprout(&file->m.mdir, &file->bshrub)) {
return LFS_ERR_NOENT;
}
// block pointer?
if (lfsr_bshrub_isbptr(&file->m.mdir, &file->bshrub)) {
if (btraversal->bid > 0) {
return LFS_ERR_NOENT;
}
if (bid_) {
*bid_ = lfsr_data_size(&file->bshrub.u.bptr.data)-1;
}
if (tinfo_) {
tinfo_->tag = LFSR_TAG_BLOCK;
tinfo_->u.bptr = file->bshrub.u.bptr;
}
return 0;
// bshrub/btree?
} else if (lfsr_bshrub_isbshruborbtree(&file->bshrub)) {
int err = lfsr_btree_traverse_(lfs, &file->bshrub.u.bshrub, btraversal,
bid_, tinfo_);
if (err) {
return err;
}
// decode bptrs
if (tinfo_ && tinfo_->tag == LFSR_TAG_BLOCK) {
lfsr_bptr_t bptr;
err = lfsr_data_readbptr(lfs, &tinfo_->u.data,
&bptr);
if (err) {
return err;
}
tinfo_->u.bptr = bptr;
}
return 0;
} else {
LFS_UNREACHABLE();
}
}
static lfs_ssize_t lfsr_bshrub_readnext(lfs_t *lfs, const lfsr_file_t *file,
lfs_off_t pos, uint8_t *buffer, lfs_size_t size) {
lfs_off_t pos_ = pos;
// read one btree entry
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_bptr_t bptr;
int err = lfsr_bshrub_lookupnext(lfs, file, pos_,
&bid, &tag, &weight, &bptr, NULL);
if (err) {
return err;
}
// any data on disk?
if (pos_ < bid-(weight-1) + lfsr_data_size(&bptr.data)) {
// note one important side-effect here is a strict
// data hint
lfs_ssize_t d = lfs_min32(
size,
lfsr_data_size(&bptr.data)
- (pos_ - (bid-(weight-1))));
lfsr_data_t slice = lfsr_data_slice(bptr.data,
pos_ - (bid-(weight-1)),
d);
d = lfsr_data_read(lfs, &slice,
buffer, d);
if (d < 0) {
return d;
}
pos_ += d;
buffer += d;
size -= d;
}
// found a hole? fill with zeros
lfs_ssize_t d = lfs_min32(size, bid+1 - pos_);
memset(buffer, 0, d);
pos_ += d;
buffer += d;
size -= d;
return pos_ - pos;
}
static lfs_ssize_t lfsr_bshrub_read(lfs_t *lfs, const lfsr_file_t *file,
lfs_off_t pos, uint8_t *buffer, lfs_size_t size) {
lfs_off_t pos_ = pos;
while (size > 0 && pos_ < lfsr_bshrub_size(&file->bshrub)) {
lfs_ssize_t d = lfsr_bshrub_readnext(lfs, file,
pos_, buffer, size);
if (d < 0) {
LFS_ASSERT(d != LFS_ERR_NOENT);
return d;
}
pos_ += d;
buffer += d;
size -= d;
}
return pos_ - pos;
}
// this is atomic
static int lfsr_bshrub_commit(lfs_t *lfs, lfsr_file_t *file, lfsr_bid_t bid,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// file must be a bshrub/btree here
LFS_ASSERT(lfsr_bshrub_isbshruborbtree(&file->bshrub));
// before we touch anything, we need to mark all other btree references
// as unerased
if (lfsr_bshrub_isbtree(&file->m.mdir, &file->bshrub)) {
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& file_ != file
&& lfsr_bshrub_isbshruborbtree(&file_->bshrub)
&& lfsr_btree_cmp(
&file_->bshrub.u.btree,
&file->bshrub.u.btree) == 0) {
// mark as unerased
file_->bshrub.u.btree.eoff = -1;
}
}
}
// we need some scratch space for tail-recursive attrs
lfsr_attr_t attrs__[4];
uint8_t buffer[2*LFSR_BRANCH_DSIZE];
// try to commit to the btree
int err = lfsr_btree_commit_(lfs, &file->bshrub.u.btree,
&bid, &attrs, &attr_count,
attrs__, buffer);
if (err && err != LFS_ERR_RANGE) {
return err;
}
LFS_ASSERT(!err || attr_count > 0);
bool alloc = (err == LFS_ERR_RANGE);
// when btree is shrubbed, lfsr_btree_commit_ stops at the root
// and returns with pending attrs
if (attr_count > 0) {
// we need to prevent our shrub from overflowing our mdir somehow
//
// maintaining an accurate estimate is tricky and error-prone,
// but recalculating an estimate every commit is expensive
//
// Instead, we keep track of an estimate of how many bytes have
// been progged to the shrub since the last estimate, and recalculate
// the estimate when this overflows our shrub_size. This mirrors how
// block_size and rbyds interact, and amortizes the estimate cost.
// figure out how much data this commit progs
lfs_size_t commit_estimate = 0;
for (lfs_size_t i = 0; i < attr_count; i++) {
// only include tag overhead if tag is not a grow/rm tag
if (!lfsr_tag_isgrow(attrs[i].tag)
&& !lfsr_tag_isrm(attrs[i].tag)) {
commit_estimate += LFSR_ATTR_ESTIMATE;
}
commit_estimate += lfsr_data_size(&attrs[i].data);
}
// does our estimate exceed our shrub_size? need to recalculate an
// accurate estimate
lfs_ssize_t estimate = (alloc)
? (lfs_size_t)-1
: file->bshrub.u.bshrub.eoff;
// this double condition avoids overflow issues
if ((lfs_size_t)estimate > lfs->cfg->shrub_size
|| estimate + commit_estimate > lfs->cfg->shrub_size) {
estimate = lfsr_bshrub_estimate(lfs, file);
if (estimate < 0) {
return estimate;
}
// two cases where we evict:
// - overlow shrub_size/2 - don't penalize for commits here
// - overlow shrub_size - must include commits or we risk overflow
//
// the 1/2 here prevents runaway performance with the shrub is
// near full, but it's a heuristic, so including the commit would
// just be mean
//
if ((lfs_size_t)estimate > lfs->cfg->shrub_size/2
|| estimate + commit_estimate > lfs->cfg->shrub_size) {
goto evict;
}
}
// include our pending commit in the new estimate
estimate += commit_estimate;
// commit to shrub
int err = lfsr_mdir_commit(lfs, &file->m.mdir, LFSR_ATTRS(
LFSR_ATTR(
TAG((alloc)
? LFSR_TAG_SHRUBALLOC
: LFSR_TAG_SHRUBCOMMIT), 0,
SHRUBCOMMIT(&file->bshrub_.u.bshrub, bid,
attrs, attr_count))));
if (err) {
return err;
}
// update _all_ shrubs with the new estimate
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& file_->m.mdir.mid == file->m.mdir.mid
&& lfsr_bshrub_isbshrub(&file_->m.mdir, &file_->bshrub)) {
file_->bshrub.u.bshrub.eoff = estimate;
}
}
LFS_ASSERT(file->bshrub.u.bshrub.eoff = (lfs_size_t)estimate);
return 0;
}
LFS_ASSERT(lfsr_shrub_hastrunk(&file->bshrub.u.bshrub));
return 0;
evict:;
// convert to btree
lfsr_rbyd_t rbyd;
err = lfsr_rbyd_alloc(lfs, &rbyd);
if (err) {
return err;
}
// note this may be a new root
if (!alloc) {
err = lfsr_rbyd_compact(lfs, &rbyd, -1, -1, &file->bshrub.u.bshrub);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
err = lfsr_rbyd_appendattrs(lfs, &rbyd, bid, -1, -1,
attrs, attr_count);
if (err) {
return err;
}
err = lfsr_rbyd_appendcksum(lfs, &rbyd);
if (err) {
return err;
}
file->bshrub.u.btree = rbyd;
return 0;
}
static int lfsr_file_carve(lfs_t *lfs, lfsr_file_t *file,
lfs_off_t pos, lfs_off_t weight, lfs_soff_t delta,
lfsr_tag_t tag, const lfsr_bptr_t *bptr, const lfsr_ecksum_t *becksum) {
// Note! This function has some rather special constraints:
//
// 1. We must never allow our btree size to overflow, even temporarily.
//
// 2. We must not lose track of bptrs until we no longer need them, to
// prevent incorrect allocation from the block allocator.
//
// 3. We should avoid copying data fragments as much as possible.
//
// These requirements end up conflicting a bit...
//
// The second requirement isn't strictly necessary if we track temporary
// copies during file writes, but it is nice to prove this constraint is
// possible in case we ever don't track temporary copies.
// try to merge commits where possible
lfsr_bid_t bid_ = lfsr_bshrub_size(&file->bshrub)-1;
lfsr_attr_t attrs[5];
lfs_size_t attr_count = 0;
lfs_size_t attr_tnuoc = 0;
uint8_t buf[3*LFSR_BPTR_DSIZE+2*LFSR_ECKSUM_DSIZE];
lfs_size_t buf_size = 0;
// always convert to bshrub/btree when this function is called
if (!lfsr_bshrub_isbshruborbtree(&file->bshrub)) {
// this does risk losing our sprout/leaf if there is an error,
// but note that's already a risk with how file carve deletes
// data before insertion
if (lfsr_bshrub_isbsprout(&file->m.mdir, &file->bshrub)) {
attrs[attr_count++] = LFSR_ATTR(
DATA, +lfsr_bshrub_size(&file->bshrub),
DATA(file->bshrub.u.bsprout));
} else if (lfsr_bshrub_isbptr(&file->m.mdir, &file->bshrub)) {
attrs[attr_count++] = LFSR_ATTR(
BLOCK, +lfsr_bshrub_size(&file->bshrub),
FROMBPTR(&file->bshrub.u.bptr, &buf[buf_size]));
buf_size += LFSR_BPTR_DSIZE;
}
file->bshrub.u.bshrub.blocks[0] = file->m.mdir.rbyd.blocks[0];
file->bshrub.u.bshrub.trunk = LFSR_RBYD_SHRUB | 0;
file->bshrub.u.bshrub.weight = 0;
// force estimate recalculation
file->bshrub.u.bshrub.eoff = -1;
if (attr_count > 0) {
LFS_ASSERT(attr_count <= sizeof(attrs)/sizeof(lfsr_attr_t));
LFS_ASSERT(buf_size <= sizeof(buf));
int err = lfsr_bshrub_commit(lfs, file, -1, attrs, attr_count);
if (err) {
return err;
}
}
attr_count = 0;
buf_size = 0;
}
// need a hole?
if (pos > lfsr_bshrub_size(&file->bshrub)) {
// can we coalesce?
if (lfsr_bshrub_size(&file->bshrub) > 0) {
attrs[attr_count++] = LFSR_ATTR(
GROW, +(pos - lfsr_bshrub_size(&file->bshrub)), NULL());
// new hole
} else {
attrs[attr_count++] = LFSR_ATTR(
DATA, +(pos - lfsr_bshrub_size(&file->bshrub)), NULL());
}
}
// try to carve any existing data
while (pos < lfsr_bshrub_size(&file->bshrub)) {
lfsr_tag_t tag_;
lfsr_bid_t weight_;
lfsr_bptr_t bptr_;
lfsr_ecksum_t becksum_;
int err = lfsr_bshrub_lookupnext(lfs, file, pos,
&bid_, &tag_, &weight_, &bptr_, &becksum_);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// note, an entry can be both a left and right sibling
lfsr_data_t left_slice_ = lfsr_data_slice(bptr_.data,
-1,
pos - (bid_-(weight_-1)));
lfsr_data_t right_slice_ = lfsr_data_slice(bptr_.data,
pos+weight - (bid_-(weight_-1)),
-1);
// left sibling needs carving but falls underneath our
// crystallization threshold? break into fragments
while (tag_ == LFSR_TAG_BLOCK
&& lfsr_data_size(&left_slice_) > lfs->cfg->fragment_size
&& lfsr_data_size(&left_slice_) < lfs->cfg->crystal_thresh) {
bptr_.data = lfsr_data_slice(bptr_.data,
lfs->cfg->fragment_size,
-1);
err = lfsr_bshrub_commit(lfs, file, bid_, LFSR_ATTRS(
LFSR_ATTR(
GROW(SUBMASK(DATA)),
-(weight_ - lfs->cfg->fragment_size),
DATA(lfsr_data_truncate(left_slice_,
lfs->cfg->fragment_size))),
LFSR_ATTR(
BLOCK, +(weight_ - lfs->cfg->fragment_size),
FROMBPTR(&bptr_, buf))));
if (err) {
return err;
}
weight_ -= lfs->cfg->fragment_size;
left_slice_ = lfsr_data_slice(bptr_.data,
-1,
pos - (bid_-(weight_-1)));
}
// right sibling needs carving but falls underneath our
// crystallization threshold? break into fragments
while (tag_ == LFSR_TAG_BLOCK
&& lfsr_data_size(&right_slice_) > lfs->cfg->fragment_size
&& lfsr_data_size(&right_slice_) < lfs->cfg->crystal_thresh) {
bptr_.data = lfsr_data_truncate(bptr_.data,
lfsr_data_size(&bptr_.data) - lfs->cfg->fragment_size);
err = lfsr_bshrub_commit(lfs, file, bid_, LFSR_ATTRS(
LFSR_ATTR(
GROW(SUBMASK(BLOCK)),
-(weight_ - lfsr_data_size(&bptr_.data)),
FROMBPTR(&bptr_, buf)),
LFSR_ATTR(
DATA, +(weight_ - lfsr_data_size(&bptr_.data)),
DATA(lfsr_data_fruncate(right_slice_,
lfs->cfg->fragment_size)))));
if (err) {
return err;
}
bid_ -= (weight_-lfsr_data_size(&bptr_.data));
weight_ -= (weight_-lfsr_data_size(&bptr_.data));
right_slice_ = lfsr_data_slice(bptr_.data,
pos+weight - (bid_-(weight_-1)),
-1);
}
// found left sibling?
if (bid_-(weight_-1) < pos) {
// can we get away with a grow attribute?
if (lfsr_data_size(&bptr_.data) == lfsr_data_size(&left_slice_)) {
attrs[attr_count++] = LFSR_ATTR(
GROW, -(bid_+1 - pos), NULL());
// carve bptr?
} else if (tag_ == LFSR_TAG_BLOCK) {
lfsr_bptr_t bptr__ = {
.data = left_slice_,
.cksize = bptr_.cksize,
.cksum = bptr_.cksum,
};
attrs[attr_count++] = LFSR_ATTR(
GROW(SUBMASK(BLOCK)), -(bid_+1 - pos),
FROMBPTR(&bptr__, &buf[buf_size]));
buf_size += LFSR_BPTR_DSIZE;
// carve fragment?
} else {
attrs[attr_count++] = LFSR_ATTR(
GROW(SUBMASK(DATA)), -(bid_+1 - pos),
DATA(left_slice_));
}
// completely overwriting this entry?
} else {
attrs[attr_count++] = LFSR_ATTR(
RM, -weight_, NULL());
}
// spans more than one entry? we can't do everything in one commit,
// so commit what we have and move on to next entry
if (pos+weight > bid_+1) {
LFS_ASSERT(lfsr_data_size(&right_slice_) == 0);
LFS_ASSERT(attr_count <= sizeof(attrs)/sizeof(lfsr_attr_t));
LFS_ASSERT(buf_size <= sizeof(buf));
err = lfsr_bshrub_commit(lfs, file, bid_,
attrs, attr_count);
if (err) {
return err;
}
delta += lfs_min32(weight, bid_+1 - pos);
weight -= lfs_min32(weight, bid_+1 - pos);
bid_ = lfsr_bshrub_size(&file->bshrub)-1;
attr_count = 0;
buf_size = 0;
continue;
}
// found right sibling?
if (pos+weight < bid_+1) {
// can we coalesce a hole?
if (lfsr_data_size(&right_slice_) == 0) {
delta += bid_+1 - (pos+weight);
// carve bptr?
} else if (tag_ == LFSR_TAG_BLOCK) {
lfsr_bptr_t bptr__ = {
.data = right_slice_,
.cksize = bptr_.cksize,
.cksum = bptr_.cksum,
};
attrs[attr_count+attr_tnuoc++] = LFSR_ATTR(
BLOCK, +(bid_+1 - (pos+weight)),
FROMBPTR(&bptr__, &buf[buf_size]));
buf_size += LFSR_BPTR_DSIZE;
// copy over becksum since erase-state is still valid
if (becksum_.size != -1) {
attrs[attr_count+attr_tnuoc++] = LFSR_ATTR(
BECKSUM, 0,
FROMECKSUM(&becksum_, &buf[buf_size]));
buf_size += LFSR_ECKSUM_DSIZE;
}
// carve fragment?
} else {
attrs[attr_count+attr_tnuoc++] = LFSR_ATTR(
DATA, +(bid_+1 - (pos+weight)),
DATA(right_slice_));
}
}
delta += lfs_min32(weight, bid_+1 - pos);
weight -= lfs_min32(weight, bid_+1 - pos);
break;
}
// finally append our data
if (weight + delta > 0) {
// can we coalesce a hole?
if ((!bptr || lfsr_data_size(&bptr->data) == 0) && pos > 0) {
memmove(&attrs[attr_count+1], &attrs[attr_count],
attr_tnuoc*sizeof(lfsr_attr_t));
attrs[attr_count++] = LFSR_ATTR(
GROW, +(weight + delta), NULL());
// need a new hole?
} else if (!bptr || lfsr_data_size(&bptr->data) == 0) {
memmove(&attrs[attr_count+1], &attrs[attr_count],
attr_tnuoc*sizeof(lfsr_attr_t));
attrs[attr_count++] = LFSR_ATTR(
DATA, +(weight + delta), NULL());
// append new fragment?
} else if (tag == LFSR_TAG_DATA) {
memmove(&attrs[attr_count+1], &attrs[attr_count],
attr_tnuoc*sizeof(lfsr_attr_t));
attrs[attr_count++] = LFSR_ATTR(
DATA, +(weight + delta), DATA(bptr->data));
// append a new block?
} else if (tag == LFSR_TAG_BLOCK) {
memmove(&attrs[attr_count+1], &attrs[attr_count],
attr_tnuoc*sizeof(lfsr_attr_t));
attrs[attr_count++] = LFSR_ATTR(
BLOCK, +(weight + delta),
FROMBPTR(bptr, &buf[buf_size]));
buf_size += LFSR_BPTR_DSIZE;
// append becksum?
if (becksum && becksum->size != -1) {
memmove(&attrs[attr_count+1], &attrs[attr_count],
attr_tnuoc*sizeof(lfsr_attr_t));
attrs[attr_count++] = LFSR_ATTR(
BECKSUM, 0,
FROMECKSUM(becksum, &buf[buf_size]));
buf_size += LFSR_ECKSUM_DSIZE;
}
} else {
LFS_UNREACHABLE();
}
}
// commit pending attrs
if (attr_count+attr_tnuoc > 0) {
LFS_ASSERT(attr_count+attr_tnuoc <= sizeof(attrs)/sizeof(lfsr_attr_t));
LFS_ASSERT(buf_size <= sizeof(buf));
int err = lfsr_bshrub_commit(lfs, file, bid_,
attrs, attr_count+attr_tnuoc);
if (err) {
return err;
}
}
return 0;
}
static int lfsr_file_flush_(lfs_t *lfs, lfsr_file_t *file,
lfs_off_t pos, const uint8_t *buffer, lfs_size_t size) {
// we can skip some btree lookups if we know we are aligned from a
// previous iteration, we already do way too many btree lookups
bool aligned = false;
// iteratively write blocks
while (size > 0) {
// first we need to figure out our current crystal, we do this
// heuristically.
//
// note that we may end up including holes in our crystal, but this
// is fine. we don't want small holes breaking up blocks anyways
// default to arbitrary alignment
lfs_off_t crystal_start = pos;
lfs_off_t crystal_end = pos + size;
lfs_off_t block_start;
lfsr_bptr_t bptr;
// within our tree? find left crystal neighbor
if (pos > 0
&& lfs->cfg->crystal_thresh > 0
&& (lfs_soff_t)(pos - (lfs->cfg->crystal_thresh-1))
< (lfs_soff_t)lfsr_bshrub_size(&file->bshrub)
&& lfsr_bshrub_size(&file->bshrub) > 0
// don't bother to lookup left after the first block
&& !aligned) {
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_ecksum_t becksum;
int err = lfsr_bshrub_lookupnext(lfs, file,
lfs_smax32(pos - (lfs->cfg->crystal_thresh-1), 0),
&bid, &tag, &weight, &bptr, &becksum);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// if left crystal neighbor is a fragment and there is no hole
// between our own crystal and our neighbor, include as a part
// of our crystal
if (tag == LFSR_TAG_DATA
&& bid-(weight-1)+lfsr_data_size(&bptr.data)
>= pos - (lfs->cfg->crystal_thresh-1)) {
crystal_start = bid-(weight-1);
// otherwise our neighbor determines our crystal boundary
} else {
crystal_start = lfs_min32(bid+1, pos);
// wait, found block-level erased-state?
if (tag == LFSR_TAG_BLOCK
&& becksum.size != -1
// data not truncated?
&& bptr.data.u.disk.off + lfsr_data_size(&bptr.data)
== bptr.cksize
// not clobbering data?
&& crystal_start - (bid-(weight-1))
>= lfsr_data_size(&bptr.data)
// enough for prog alignment?
&& crystal_end - crystal_start
>= lfs->cfg->prog_size) {
LFS_ASSERT(bptr.cksize + becksum.size
<= lfs->cfg->block_size);
err = lfsr_ecksum_validate(lfs, &becksum,
bptr.data.u.disk.block, bptr.cksize);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// found _valid_ block-level erased-state? eagerly
// append
if (err != LFS_ERR_CORRUPT) {
block_start = bid-(weight-1);
goto compact;
}
}
}
}
// if we haven't already exceeded our crystallization threshold,
// find right crystal neighbor
if (crystal_end - crystal_start < lfs->cfg->crystal_thresh
&& lfsr_bshrub_size(&file->bshrub) > 0) {
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
int err = lfsr_bshrub_lookupnext(lfs, file,
lfs_min32(
crystal_start + (lfs->cfg->crystal_thresh-1),
lfsr_bshrub_size(&file->bshrub)-1),
&bid, &tag, &weight, &bptr, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// if right crystal neighbor is a fragment, include as a part
// of our crystal
if (tag == LFSR_TAG_DATA) {
crystal_end = lfs_max32(
bid-(weight-1)+lfsr_data_size(&bptr.data),
pos + size);
// otherwise treat as crystal boundary
} else {
crystal_end = lfs_max32(
bid-(weight-1),
pos + size);
}
}
// below our crystallization threshold? fallback to writing fragments
if (crystal_end - crystal_start < lfs->cfg->crystal_thresh
// enough for prog alignment?
|| crystal_end - crystal_start < lfs->cfg->prog_size) {
break;
}
// exceeded our crystallization threshold? compact into a new block
// before we can compact we need to figure out the best block
// alignment, we use the entry immediately to the left of our
// crystal for this
block_start = crystal_start;
if (crystal_start > 0
&& lfsr_bshrub_size(&file->bshrub) > 0
// don't bother to lookup left after the first block
&& !aligned) {
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_ecksum_t becksum;
int err = lfsr_bshrub_lookupnext(lfs, file,
lfs_min32(
crystal_start-1,
lfsr_bshrub_size(&file->bshrub)-1),
&bid, &tag, &weight, &bptr, &becksum);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// is our left neighbor in the same block?
if (crystal_start - (bid-(weight-1))
< lfs->cfg->block_size
&& lfsr_data_size(&bptr.data) > 0) {
block_start = bid-(weight-1);
// wait, found block-level erased-state?
if (tag == LFSR_TAG_BLOCK
&& becksum.size != -1
// data not truncated?
&& bptr.data.u.disk.off + lfsr_data_size(&bptr.data)
== bptr.cksize
// not clobbering data?
&& crystal_start - (bid-(weight-1))
>= lfsr_data_size(&bptr.data)
// enough for prog alignment?
&& crystal_end - crystal_start
>= lfs->cfg->prog_size) {
LFS_ASSERT(bptr.cksize + becksum.size
<= lfs->cfg->block_size);
err = lfsr_ecksum_validate(lfs, &becksum,
bptr.data.u.disk.block, bptr.cksize);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// found _valid_ block-level erased-state? eagerly
// append
if (err != LFS_ERR_CORRUPT) {
goto compact;
}
}
// no? is our left neighbor at least our left block neighbor?
// align to block alignment
} else if (crystal_start - (bid-(weight-1))
< 2*lfs->cfg->block_size
&& lfsr_data_size(&bptr.data) > 0) {
block_start = bid-(weight-1) + lfs->cfg->block_size;
}
}
// allocate a new block
int err = lfs_alloc(lfs, &bptr.data.u.disk.block);
if (err) {
return err;
}
// TODO should lfs_alloc handle erase?
err = lfsr_bd_erase(lfs, bptr.data.u.disk.block);
if (err) {
return err;
}
bptr.data = LFSR_DATA_DISK(bptr.data.u.disk.block, 0, 0);
bptr.cksize = 0;
bptr.cksum = 0;
compact:;
// compact data into our new block
//
// eagerly merge any right neighbors we see unless that would
// put us over our block size
lfs_off_t pos_ = block_start + lfsr_data_size(&bptr.data);
while (pos_ < lfs_min32(
block_start
+ (lfs->cfg->block_size - bptr.data.u.disk.off),
lfs_max32(
pos + size,
lfsr_bshrub_size(&file->bshrub)))) {
// keep track of the next highest priority data offset
lfs_ssize_t d = lfs_min32(
block_start
+ (lfs->cfg->block_size - bptr.data.u.disk.off),
lfs_max32(
pos + size,
lfsr_bshrub_size(&file->bshrub))) - pos_;
// any data in our buffer?
if (pos_ < pos + size && size > 0) {
if (pos_ >= pos) {
lfs_ssize_t d_ = lfs_min32(
d,
size - (pos_ - pos));
err = lfsr_bd_prog(lfs, bptr.data.u.disk.block,
bptr.cksize,
&buffer[pos_ - pos], d_,
NULL, &bptr.cksum);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
pos_ += d_;
bptr.cksize += d_;
d -= d_;
}
// buffered data takes priority
d = lfs_min32(d, pos - pos_);
}
// any data on disk?
if (pos_ < lfsr_bshrub_size(&file->bshrub)) {
lfsr_bid_t bid_;
lfsr_tag_t tag_;
lfsr_bid_t weight_;
lfsr_bptr_t bptr_;
err = lfsr_bshrub_lookupnext(lfs, file, pos_,
&bid_, &tag_, &weight_, &bptr_, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// make sure to include all of our crystal, or else this
// loop may never terminate
if (bid_-(weight_-1) >= crystal_end
// is this data a pure hole? stop early to better
// leverage becksums in sparse files
&& (pos_ >= bid_-(weight_-1)
+ lfsr_data_size(&bptr_.data)
// does this data exceed our block_size?
// stop early to try to avoid messing up
// block alignment
|| bid_-(weight_-1) + lfsr_data_size(&bptr_.data)
- block_start
> lfs->cfg->block_size)) {
break;
}
if (pos_ < bid_-(weight_-1) + lfsr_data_size(&bptr_.data)) {
// note one important side-effect here is a strict
// data hint
lfs_ssize_t d_ = lfs_min32(
d,
lfsr_data_size(&bptr_.data)
- (pos_ - (bid_-(weight_-1))));
err = lfsr_bd_progdata(lfs, bptr.data.u.disk.block,
bptr.cksize,
lfsr_data_slice(bptr_.data,
pos_ - (bid_-(weight_-1)),
d_),
NULL, &bptr.cksum);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
pos_ += d_;
bptr.cksize += d_;
d -= d_;
}
// found a hole? just make sure next leaf takes priority
d = lfs_min32(d, bid_+1 - pos_);
}
// found a hole? fill with zeros
// TODO do something better than byte-level progs here
for (lfs_size_t i = 0; i < (lfs_size_t)d; i++) {
err = lfsr_bd_prog(lfs, bptr.data.u.disk.block,
bptr.cksize + i,
&(uint8_t){0}, 1,
NULL, &bptr.cksum);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
pos_ += d;
bptr.cksize += d;
}
// A bit of a hack here, we need to truncate our block to prog_size
// alignment to avoid padding issues. Doing this retroactively to
// the pcache greatly simplifies the above loop, though we may end
// up reading more than is strictly necessary.
lfs_ssize_t d = bptr.cksize % lfs->cfg->prog_size;
LFS_ASSERT((lfs_size_t)d <= lfs->pcache.size);
lfs->pcache.size -= d;
bptr.cksize -= d;
// TODO validate?
// finalize our write
err = lfsr_bd_flush(lfs,
&bptr.cksum);
if (err) {
return err;
}
// TODO this is a cludge, but right now our bd layer is a mess,
// we need caches to be clean so becksum calculation does not pick
// up out-of-date pcaches/rcaches
lfs_cache_drop(lfs, &lfs->pcache);
lfs_cache_drop(lfs, &lfs->rcache);
// prepare our block pointer
LFS_ASSERT(bptr.cksize > 0);
LFS_ASSERT(bptr.cksize <= lfs->cfg->block_size);
bptr.data = LFSR_DATA_DISK(
bptr.data.u.disk.block,
bptr.data.u.disk.off,
bptr.cksize - bptr.data.u.disk.off);
lfs_off_t block_end = block_start + lfsr_data_size(&bptr.data);
// do we have space for a block ecksum?
lfsr_ecksum_t becksum = {.size=-1};
if (bptr.cksize < lfs->cfg->block_size) {
becksum.size = lfs->cfg->prog_size;
becksum.cksum = 0;
err = lfsr_bd_cksum(lfs,
bptr.data.u.disk.block, bptr.cksize, becksum.size,
becksum.size,
&becksum.cksum);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
}
// and write it into our tree
err = lfsr_file_carve(lfs, file,
block_start, block_end - block_start, 0,
LFSR_TAG_BLOCK, &bptr, &becksum);
if (err) {
return err;
}
// note compacting fragments -> blocks may not actually make any
// progress on flushing the buffer on the first pass
d = lfs_max32(pos, block_end) - pos;
pos += d;
buffer += lfs_min32(d, size);
size -= lfs_min32(d, size);
aligned = true;
}
// iteratively write fragments (inlined leaves)
while (size > 0) {
// truncate to our fragment size
lfs_off_t fragment_start = pos;
lfs_off_t fragment_end = fragment_start
+ lfs_min32(size, lfs->cfg->fragment_size);
lfsr_data_t data = LFSR_DATA_BUF(
buffer,
fragment_end - fragment_start);
lfsr_data_t datas[3];
lfs_size_t data_count = 0;
datas[data_count++] = data;
// do we have a left sibling?
if (fragment_start > 0
&& lfsr_bshrub_size(&file->bshrub) >= fragment_start
// don't bother to lookup left after first fragment
&& !aligned) {
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_bptr_t bptr;
int err = lfsr_bshrub_lookupnext(lfs, file,
fragment_start-1,
&bid, &tag, &weight, &bptr, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// can we coalesce?
if (bid-(weight-1) + lfsr_data_size(&bptr.data) >= fragment_start
&& fragment_end - (bid-(weight-1))
<= lfs->cfg->fragment_size) {
// coalesce, but truncate to our fragment size
// TODO this is a bit of a hacky way to prepend data...
LFS_ASSERT(data_count == 1);
datas[0] = lfsr_data_truncate(bptr.data,
fragment_start - (bid-(weight-1)));
datas[1] = lfsr_data_truncate(data,
lfs->cfg->fragment_size
- (fragment_start - (bid-(weight-1))));
data_count = 2;
data = lfsr_data_fromcat(datas, data_count);
fragment_start = bid-(weight-1);
fragment_end = fragment_start + lfsr_data_size(&data);
}
}
// do we have a right sibling?
//
// note this may the same as our left sibling
if (fragment_end < lfsr_bshrub_size(&file->bshrub)
// don't bother to lookup right if fragment is already full
&& fragment_end - fragment_start < lfs->cfg->fragment_size) {
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_bptr_t bptr;
int err = lfsr_bshrub_lookupnext(lfs, file,
fragment_end,
&bid, &tag, &weight, &bptr, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// can we coalesce?
if (fragment_end < bid-(weight-1) + lfsr_data_size(&bptr.data)
&& bid-(weight-1) + lfsr_data_size(&bptr.data)
- fragment_start
<= lfs->cfg->fragment_size) {
datas[data_count++] = lfsr_data_fruncate(bptr.data,
bid-(weight-1) + lfsr_data_size(&bptr.data)
- fragment_end);
data = lfsr_data_fromcat(datas, data_count);
fragment_end = fragment_start + lfsr_data_size(&data);
}
}
// make sure we didn't overflow our data buffer
LFS_ASSERT(data_count <= 3);
// once we've figured out what fragment to write, carve it into
// our tree
int err = lfsr_file_carve(lfs, file,
fragment_start, fragment_end - fragment_start, 0,
LFSR_TAG_DATA, &(const lfsr_bptr_t){.data=data}, NULL);
if (err && err != LFS_ERR_RANGE) {
return err;
}
// to next fragment
lfs_ssize_t d = fragment_end - pos;
pos += d;
buffer += lfs_min32(d, size);
size -= lfs_min32(d, size);
aligned = true;
}
return 0;
}
// our high-level file operations
lfs_ssize_t lfsr_file_read(lfs_t *lfs, lfsr_file_t *file,
void *buffer, lfs_size_t size) {
// can't read from writeonly files
LFS_ASSERT(!lfsr_o_iswronly(file->m.flags));
LFS_ASSERT(file->pos + size <= 0x7fffffff);
lfs_off_t pos_ = file->pos;
uint8_t *buffer_ = buffer;
while (size > 0 && pos_ < lfsr_file_size_(file)) {
// keep track of the next highest priority data offset
lfs_ssize_t d = lfs_min32(size, lfsr_file_size_(file) - pos_);
// any data in our buffer?
if (pos_ < file->buffer_pos + file->buffer_size
&& file->buffer_size != 0) {
if (pos_ >= file->buffer_pos) {
lfs_ssize_t d_ = lfs_min32(
d,
file->buffer_size - (pos_ - file->buffer_pos));
memcpy(buffer_,
&file->buffer[pos_ - file->buffer_pos],
d_);
pos_ += d_;
buffer_ += d_;
size -= d_;
d -= d_;
continue;
}
// buffered data takes priority
d = lfs_min32(d, file->buffer_pos - pos_);
}
// any data in our btree?
if (pos_ < lfsr_bshrub_size(&file->bshrub)) {
// bypass buffer?
if ((lfs_size_t)d >= lfs->cfg->cache_size) {
lfs_ssize_t d_ = lfsr_bshrub_readnext(lfs, file,
pos_, buffer_, d);
if (d_ < 0) {
LFS_ASSERT(d_ != LFS_ERR_NOENT);
return d_;
}
pos_ += d_;
buffer_ += d_;
size -= d_;
continue;
}
// buffer in use? we need to flush it
//
// note that flush does not change the actual file data, so if
// a read fails it's ok to fall back to our flushed state
//
if (lfsr_f_isunflush(file->m.flags)) {
int err = lfsr_file_flush(lfs, file);
if (err) {
return err;
}
file->buffer_pos = 0;
file->buffer_size = 0;
}
// try to fill our buffer with some data
lfs_ssize_t d_ = lfsr_bshrub_readnext(lfs, file,
pos_, file->buffer, d);
if (d_ < 0) {
LFS_ASSERT(d != LFS_ERR_NOENT);
return d_;
}
file->buffer_pos = pos_;
file->buffer_size = d_;
continue;
}
// found a hole? fill with zeros
memset(buffer_, 0, d);
pos_ += d;
buffer_ += d;
size -= d;
}
// update file and return amount read
lfs_size_t read = pos_ - file->pos;
file->pos = pos_;
return read;
}
lfs_ssize_t lfsr_file_write(lfs_t *lfs, lfsr_file_t *file,
const void *buffer, lfs_size_t size) {
// can't write to readonly files
LFS_ASSERT(!lfsr_o_isrdonly(file->m.flags));
// would this write make our file larger than our size limit?
if (size > lfs->size_limit - file->pos) {
return LFS_ERR_FBIG;
}
// size=0 is a bit special and is guaranteed to have no effects on the
// underlying file, this means no updating file pos or file size
//
// since we need to test for this, just return early
if (size == 0) {
return 0;
}
// checkpoint the allocator
lfs_alloc_ckpoint(lfs);
int err;
// update pos if we are appending
lfs_off_t pos = file->pos;
if (lfsr_o_isappend(file->m.flags)) {
pos = lfsr_file_size_(file);
}
// if we're a small file, we may need to append zeros
if (pos > lfsr_file_size_(file)
&& pos <= lfs->cfg->cache_size
&& pos <= lfs->cfg->inline_size
&& pos <= lfs->cfg->fragment_size) {
LFS_ASSERT(lfsr_f_isunflush(file->m.flags));
LFS_ASSERT(lfsr_file_size_(file) == file->buffer_size);
memset(&file->buffer[file->buffer_size],
0,
pos - file->buffer_size);
file->buffer_size = pos;
}
const uint8_t *buffer_ = buffer;
lfs_size_t written = 0;
while (size > 0) {
// bypass buffer?
//
// note we flush our buffer before bypassing writes, this isn't
// strictly necessary, but enforces a more intuitive write order
// and avoids weird cases with low-level write heuristics
//
if (!lfsr_f_isunflush(file->m.flags)
&& size >= lfs->cfg->cache_size) {
err = lfsr_file_flush_(lfs, file,
pos, buffer_, size);
if (err) {
goto failed;
}
// after success, fill our buffer with the tail of our write
//
// note we need to clear the buffer anyways to avoid any
// out-of-date data
file->buffer_pos = pos + size - lfs->cfg->cache_size;
memcpy(file->buffer,
&buffer_[size - lfs->cfg->cache_size],
lfs->cfg->cache_size);
file->buffer_size = lfs->cfg->cache_size;
written += size;
pos += size;
buffer_ += size;
size -= size;
continue;
}
// try to fill our buffer
//
// This is a bit delicate, since our buffer contains both old and
// new data, but note:
//
// 1. We only write to yet unused buffer memory.
//
// 2. Bypassing the buffer above means we only write to the
// buffer once, and flush at most twice.
//
if (!lfsr_f_isunflush(file->m.flags)
|| (pos >= file->buffer_pos
&& pos <= file->buffer_pos + file->buffer_size
&& pos < file->buffer_pos + lfs->cfg->cache_size)) {
// unused buffer? we can move it where we need it
if (!lfsr_f_isunflush(file->m.flags)) {
file->buffer_pos = pos;
file->buffer_size = 0;
}
lfs_size_t d = lfs_min32(
size,
lfs->cfg->cache_size - (pos - file->buffer_pos));
memcpy(&file->buffer[pos - file->buffer_pos], buffer_, d);
file->buffer_size = lfs_max32(
file->buffer_size,
pos+d - file->buffer_pos);
file->m.flags |= LFS_F_UNFLUSH;
written += d;
pos += d;
buffer_ += d;
size -= d;
continue;
}
// flush our buffer so the above can't fail
err = lfsr_file_flush_(lfs, file,
file->buffer_pos, file->buffer, file->buffer_size);
if (err) {
goto failed;
}
file->m.flags &= ~LFS_F_UNFLUSH;
}
// mark as unsynced
file->m.flags |= LFS_F_UNSYNC;
// update our pos
file->pos = pos;
// flush if requested
//
// this seems unreachable, but it's possible if we transition from
// a small file to a non-small file
if (lfsr_o_isflush(file->m.flags)) {
err = lfsr_file_flush(lfs, file);
if (err) {
goto failed;
}
}
// sync if requested
if (lfsr_o_issync(file->m.flags)) {
err = lfsr_file_sync(lfs, file);
if (err) {
goto failed;
}
}
return written;
failed:;
// mark as desync so lfsr_file_close doesn't write to disk
file->m.flags |= LFS_O_DESYNC;
return err;
}
int lfsr_file_flush(lfs_t *lfs, lfsr_file_t *file) {
// readonly files should do nothing
LFS_ASSERT(!lfsr_o_isrdonly(file->m.flags)
|| !lfsr_f_isunflush(file->m.flags)
|| (lfsr_file_size_(file) <= lfs->cfg->cache_size
&& lfsr_file_size_(file) <= lfs->cfg->inline_size
&& lfsr_file_size_(file) <= lfs->cfg->fragment_size));
// do nothing if our file is already flushed
if (!lfsr_f_isunflush(file->m.flags)) {
return 0;
}
// do nothing if our file is small
//
// note this means small files remain perpetually unflushed
if (lfsr_file_size_(file) <= lfs->cfg->cache_size
&& lfsr_file_size_(file) <= lfs->cfg->inline_size
&& lfsr_file_size_(file) <= lfs->cfg->fragment_size) {
// our file must reside entirely in our buffer
LFS_ASSERT(file->buffer_pos == 0);
return 0;
}
// checkpoint the allocator
lfs_alloc_ckpoint(lfs);
int err;
// flush our buffer if it contains any unwritten data
if (lfsr_f_isunflush(file->m.flags)
&& file->buffer_size != 0) {
// flush
err = lfsr_file_flush_(lfs, file,
file->buffer_pos, file->buffer, file->buffer_size);
if (err) {
goto failed;
}
}
// mark as flushed
file->m.flags &= ~LFS_F_UNFLUSH;
return 0;
failed:;
// mark as desync so lfsr_file_close doesn't write to disk
file->m.flags |= LFS_O_DESYNC;
return err;
}
int lfsr_file_sync(lfs_t *lfs, lfsr_file_t *file) {
// removed? we can't sync
if (lfsr_f_iszombie(file->m.flags)) {
return LFS_ERR_NOENT;
}
// first flush any data in our buffer, this is a noop if already
// flushed
//
// note that flush does not change the actual file data, so if
// flush succeeds but mdir commit fails it's ok to fall back to
// our flushed state
//
int err = lfsr_file_flush(lfs, file);
if (err) {
goto failed;
}
// note because of small-file caching and our current write
// strategy, we never actually end up with only a direct data
// or bptr
//
// this is convenient because bptrs are a bit annoying to commit
LFS_ASSERT(!lfsr_bshrub_isbsprout(&file->m.mdir, &file->bshrub));
LFS_ASSERT(!lfsr_bshrub_isbptr(&file->m.mdir, &file->bshrub));
// small files should start as zero, const prop should optimize this out
LFS_ASSERT(!lfsr_f_isunflush(file->m.flags)
|| file->buffer_pos == 0);
// small files/btree should be exclusive here
LFS_ASSERT(!lfsr_f_isunflush(file->m.flags)
|| lfsr_bshrub_size(&file->bshrub) == 0);
// small files must be inlined entirely in our buffer
LFS_ASSERT(!lfsr_f_isunflush(file->m.flags)
|| (file->buffer_size <= lfs->cfg->cache_size
&& file->buffer_size <= lfs->cfg->inline_size
&& file->buffer_size <= lfs->cfg->fragment_size));
// uncreat files must be unsync
LFS_ASSERT(!lfsr_f_isorphan(file->m.flags)
|| lfsr_f_isunsync(file->m.flags));
// don't write to disk if our disk is already in-sync
if (lfsr_f_isunsync(file->m.flags)) {
// readonly files should do nothing
//
// but readonly files _can_ end up unsynced, in the roundabout
// case where:
//
// 1. a file is opened rdonly + desync
// 2. the same file is opened and written to
// 3. we try to sync our original file handle
//
// the best thing we can do in this case is return an error
if (lfsr_o_isrdonly(file->m.flags)) {
err = LFS_ERR_INVAL;
goto failed;
}
// checkpoint the allocator again
lfs_alloc_ckpoint(lfs);
// commit our file's metadata
lfsr_attr_t attrs[2];
lfs_size_t attr_count = 0;
uint8_t buf[LFSR_BTREE_DSIZE];
lfs_size_t buf_size = 0;
// not created yet? need to convert orphan to normal file
if (lfsr_f_isorphan(file->m.flags)) {
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &file->m.mdir,
file->m.mdir.mid, LFSR_TAG_ORPHAN,
&data);
if (err) {
// we must have an orphan at this point
LFS_ASSERT(err != LFS_ERR_NOENT);
goto failed;
}
attrs[attr_count++] = LFSR_ATTR(
SUBMASK(REG), 0, DATA(data));
}
// commit the file state
// null? no attr?
if (lfsr_f_isunflush(file->m.flags) && file->buffer_size == 0) {
attrs[attr_count++] = LFSR_ATTR(
SUBMASK(RM(STRUCT)), 0,
NULL());
// small file inlined in mdir?
} else if (lfsr_f_isunflush(file->m.flags)) {
attrs[attr_count++] = LFSR_ATTR(
SUBMASK(DATA), 0,
BUF(file->buffer, file->buffer_size));
// bshrub?
} else if (lfsr_bshrub_isbshrub(&file->m.mdir, &file->bshrub)) {
attrs[attr_count++] = LFSR_ATTR(
SUBMASK(SHRUBTRUNK), 0,
SHRUBTRUNK(&file->bshrub_.u.bshrub));
// btree?
} else if (lfsr_bshrub_isbtree(&file->m.mdir, &file->bshrub)) {
attrs[attr_count++] = LFSR_ATTR(
SUBMASK(BTREE), 0,
FROMBTREE(&file->bshrub.u.btree, &buf[buf_size]));
buf_size += LFSR_BTREE_DSIZE;
} else {
LFS_UNREACHABLE();
}
LFS_ASSERT(attr_count <= sizeof(attrs)/sizeof(lfsr_attr_t));
LFS_ASSERT(buf_size <= sizeof(buf));
err = lfsr_mdir_commit(lfs, &file->m.mdir,
attrs, attr_count);
if (err) {
goto failed;
}
}
// but do update other file handles
for (lfsr_opened_t *opened_ = lfs->opened;
opened_;
opened_ = opened_->next) {
lfsr_file_t *file_ = (lfsr_file_t*)opened_;
if (file_->m.type == LFS_TYPE_REG
&& file_->m.mdir.mid == file->m.mdir.mid
// don't double update
&& file_ != file) {
// notify all files of creation
file_->m.flags &= ~LFS_F_ORPHAN;
// mark desynced files an unsynced
if (lfsr_o_isdesync(file_->m.flags)) {
file_->m.flags |= LFS_F_UNSYNC;
// update synced files
} else {
file_->m.flags &= ~LFS_F_UNSYNC;
if (lfsr_f_isunflush(file->m.flags)) {
file_->m.flags |= LFS_F_UNFLUSH;
} else {
file_->m.flags &= ~LFS_F_UNFLUSH;
}
file_->bshrub = file->bshrub;
file_->buffer_pos = file->buffer_pos;
LFS_ASSERT(file->buffer_size <= lfs->cfg->cache_size);
memcpy(file_->buffer, file->buffer, file->buffer_size);
file_->buffer_size = file->buffer_size;
}
}
}
// mark as synced
file->m.flags &= ~LFS_F_UNSYNC & ~LFS_F_ORPHAN & ~LFS_O_DESYNC;
return 0;
failed:;
file->m.flags |= LFS_O_DESYNC;
return err;
}
int lfsr_file_desync(lfs_t *lfs, lfsr_file_t *file) {
(void)lfs;
file->m.flags |= LFS_O_DESYNC;
return 0;
}
lfs_soff_t lfsr_file_seek(lfs_t *lfs, lfsr_file_t *file,
lfs_soff_t off, uint8_t whence) {
// TODO check for out-of-range?
// figure out our new file position
lfs_off_t pos_;
if (whence == LFS_SEEK_SET) {
pos_ = off;
} else if (whence == LFS_SEEK_CUR) {
pos_ = file->pos + off;
} else if (whence == LFS_SEEK_END) {
pos_ = lfsr_file_size_(file) + off;
} else {
LFS_UNREACHABLE();
}
// out of range?
if (pos_ > lfs->size_limit) {
return LFS_ERR_INVAL;
}
// update file position
file->pos = pos_;
return pos_;
}
lfs_soff_t lfsr_file_tell(lfs_t *lfs, lfsr_file_t *file) {
(void)lfs;
return file->pos;
}
lfs_soff_t lfsr_file_rewind(lfs_t *lfs, lfsr_file_t *file) {
(void)lfs;
file->pos = 0;
return 0;
}
lfs_soff_t lfsr_file_size(lfs_t *lfs, lfsr_file_t *file) {
(void)lfs;
return lfsr_file_size_(file);
}
int lfsr_file_truncate(lfs_t *lfs, lfsr_file_t *file, lfs_off_t size_) {
// exceeds our size limit?
if (size_ > lfs->size_limit) {
return LFS_ERR_FBIG;
}
// do nothing if our size does not change
lfs_off_t size = lfsr_file_size_(file);
if (lfsr_file_size_(file) == size_) {
return 0;
}
// checkpoint the allocator
lfs_alloc_ckpoint(lfs);
int err;
// does our file become small?
if (size_ <= lfs->cfg->cache_size
&& size_ <= lfs->cfg->inline_size
&& size_ <= lfs->cfg->fragment_size) {
// if our data is not already in our buffer we unfortunately
// need to flush so our buffer is available to hold everything
if (file->buffer_pos > 0
|| file->buffer_size < lfs_min32(
size_,
lfsr_bshrub_size(&file->bshrub))) {
err = lfsr_file_flush(lfs, file);
if (err) {
goto failed;
}
file->buffer_pos = 0;
file->buffer_size = 0;
lfs_ssize_t d = lfsr_bshrub_read(lfs, file,
0, file->buffer, size_);
if (d < 0) {
err = d;
goto failed;
}
file->buffer_pos = 0;
file->buffer_size = size_;
}
// we may need to zero some of our buffer
if (size_ > file->buffer_size) {
memset(&file->buffer[file->buffer_size],
0,
size_ - file->buffer_size);
}
// small files remain perpetually unflushed
file->m.flags |= LFS_F_UNFLUSH;
file->buffer_pos = 0;
file->buffer_size = size_;
file->bshrub = LFSR_BSHRUB_BNULL();
// truncate our file normally
} else {
// truncate our btree
err = lfsr_file_carve(lfs, file,
lfs_min32(size, size_),
size - lfs_min32(size, size_),
+size_ - size,
LFSR_TAG_DATA, NULL, NULL);
if (err) {
goto failed;
}
// truncate our buffer
file->buffer_pos = lfs_min32(file->buffer_pos, size_);
file->buffer_size = lfs_min32(
file->buffer_size,
size_ - lfs_min32(file->buffer_pos, size_));
}
// mark as unsynced
file->m.flags |= LFS_F_UNSYNC;
// flush if requested
//
// this seems unreachable, but it's possible if we transition from
// a small file to a non-small file
if (lfsr_o_isflush(file->m.flags)) {
err = lfsr_file_flush(lfs, file);
if (err) {
goto failed;
}
}
// sync if requested
if (lfsr_o_issync(file->m.flags)) {
err = lfsr_file_sync(lfs, file);
if (err) {
goto failed;
}
}
return 0;
failed:;
// mark as desync so lfsr_file_close doesn't write to disk
file->m.flags |= LFS_O_DESYNC;
return err;
}
int lfsr_file_fruncate(lfs_t *lfs, lfsr_file_t *file, lfs_off_t size_) {
// exceeds our size limit?
if (size_ > lfs->size_limit) {
return LFS_ERR_FBIG;
}
// do nothing if our size does not change
lfs_off_t size = lfsr_file_size_(file);
if (size == size_) {
return 0;
}
// checkpoint the allocator
lfs_alloc_ckpoint(lfs);
int err;
// does our file become small?
if (size_ <= lfs->cfg->cache_size
&& size_ <= lfs->cfg->inline_size
&& size_ <= lfs->cfg->fragment_size) {
// if our data is not already in our buffer we unfortunately
// need to flush so our buffer is available to hold everything
if (file->buffer_pos + file->buffer_size
< lfsr_bshrub_size(&file->bshrub)
|| file->buffer_size < lfs_min32(
size_,
lfsr_bshrub_size(&file->bshrub))) {
err = lfsr_file_flush(lfs, file);
if (err) {
goto failed;
}
file->buffer_pos = 0;
file->buffer_size = 0;
lfs_ssize_t d = lfsr_bshrub_read(lfs, file,
lfsr_bshrub_size(&file->bshrub) - lfs_min32(
size_,
lfsr_bshrub_size(&file->bshrub)),
file->buffer, size_);
if (d < 0) {
err = d;
goto failed;
}
file->buffer_pos = 0;
file->buffer_size = size_;
}
// we may need to move the data in our buffer
if (file->buffer_size > size_) {
memmove(file->buffer,
&file->buffer[file->buffer_size - size_],
file->buffer_size);
}
// we may need to zero some of our buffer
if (size_ > file->buffer_size) {
memmove(&file->buffer[size_ - file->buffer_size],
file->buffer,
file->buffer_size);
memset(file->buffer,
0,
size_ - file->buffer_size);
}
// small files remain perpetually unflushed
file->m.flags |= LFS_F_UNFLUSH;
file->buffer_pos = 0;
file->buffer_size = size_;
file->bshrub = LFSR_BSHRUB_BNULL();
// fruncate our file normally
} else {
// fruncate our btree
err = lfsr_file_carve(lfs, file,
0,
lfs_smax32(size - size_, 0),
+size_ - size,
LFSR_TAG_DATA, NULL, NULL);
if (err) {
goto failed;
}
// fruncate our buffer
memmove(file->buffer,
&file->buffer[lfs_min32(
lfs_smax32(
size - size_ - file->buffer_pos,
0),
file->buffer_size)],
file->buffer_size - lfs_min32(
lfs_smax32(
size - size_ - file->buffer_pos,
0),
file->buffer_size));
file->buffer_size -= lfs_min32(
lfs_smax32(
size - size_ - file->buffer_pos,
0),
file->buffer_size);
file->buffer_pos -= lfs_smin32(
size - size_,
file->buffer_pos);
}
// mark as unsynced
file->m.flags |= LFS_F_UNSYNC;
// flush if requested
//
// this seems unreachable, but it's possible if we transition from
// a small file to a non-small file
if (lfsr_o_isflush(file->m.flags)) {
err = lfsr_file_flush(lfs, file);
if (err) {
goto failed;
}
}
// sync if requested
if (lfsr_o_issync(file->m.flags)) {
err = lfsr_file_sync(lfs, file);
if (err) {
goto failed;
}
}
return 0;
failed:;
// mark as desync so lfsr_file_close doesn't write to disk
file->m.flags |= LFS_O_DESYNC;
return err;
}
///// Metadata pair and directory operations ///
//static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
// lfs_tag_t gmask, lfs_tag_t gtag,
// lfs_off_t goff, void *gbuffer, lfs_size_t gsize) {
// lfs_off_t off = dir->off;
// lfs_tag_t ntag = dir->etag;
// lfs_stag_t gdiff = 0;
//
// if (lfs_gstate_hasmovehere(&lfs->gdisk, dir->pair) &&
// lfs_tag_id(gmask) != 0 &&
// lfs_tag_id(lfs->gdisk.tag) <= lfs_tag_id(gtag)) {
// // synthetic moves
// gdiff -= LFS_MKTAG(0, 1, 0);
// }
//
// // iterate over dir block backwards (for faster lookups)
// while (off >= sizeof(lfs_tag_t) + lfs_tag_dsize(ntag)) {
// off -= lfs_tag_dsize(ntag);
// lfs_tag_t tag = ntag;
// int err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, sizeof(ntag),
// dir->pair[0], off, &ntag, sizeof(ntag));
// if (err) {
// return err;
// }
//
// ntag = (lfs_frombe32(ntag) ^ tag) & 0x7fffffff;
//
// if (lfs_tag_id(gmask) != 0 &&
// lfs_tag_type1(tag) == LFS_TYPE_SPLICE &&
// lfs_tag_id(tag) <= lfs_tag_id(gtag - gdiff)) {
// if (tag == (LFS_MKTAG(LFS_TYPE_CREATE, 0, 0) |
// (LFS_MKTAG(0, 0x3ff, 0) & (gtag - gdiff)))) {
// // found where we were created
// return LFS_ERR_NOENT;
// }
//
// // move around splices
// gdiff += LFS_MKTAG(0, lfs_tag_splice(tag), 0);
// }
//
// if ((gmask & tag) == (gmask & (gtag - gdiff))) {
// if (lfs_tag_isdelete(tag)) {
// return LFS_ERR_NOENT;
// }
//
// lfs_size_t diff = lfs_min(lfs_tag_size(tag), gsize);
// err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, diff,
// dir->pair[0], off+sizeof(tag)+goff, gbuffer, diff);
// if (err) {
// return err;
// }
//
// memset((uint8_t*)gbuffer + diff, 0, gsize - diff);
//
// return tag + gdiff;
// }
// }
//
// return LFS_ERR_NOENT;
//}
//
//static lfs_stag_t lfs_dir_get(lfs_t *lfs, const lfs_mdir_t *dir,
// lfs_tag_t gmask, lfs_tag_t gtag, void *buffer) {
// return lfs_dir_getslice(lfs, dir,
// gmask, gtag,
// 0, buffer, lfs_tag_size(gtag));
//}
//
//static int lfs_dir_getread(lfs_t *lfs, const lfs_mdir_t *dir,
// const lfs_cache_t *pcache, lfs_cache_t *rcache, lfs_size_t hint,
// lfs_tag_t gmask, lfs_tag_t gtag,
// lfs_off_t off, void *buffer, lfs_size_t size) {
// uint8_t *data = buffer;
// if (off+size > lfs->cfg->block_size) {
// return LFS_ERR_CORRUPT;
// }
//
// while (size > 0) {
// lfs_size_t diff = size;
//
// if (pcache && pcache->block == LFS_BLOCK_INLINE &&
// off < pcache->off + pcache->size) {
// if (off >= pcache->off) {
// // is already in pcache?
// diff = lfs_min(diff, pcache->size - (off-pcache->off));
// memcpy(data, &pcache->buffer[off-pcache->off], diff);
//
// data += diff;
// off += diff;
// size -= diff;
// continue;
// }
//
// // pcache takes priority
// diff = lfs_min(diff, pcache->off-off);
// }
//
// if (rcache->block == LFS_BLOCK_INLINE &&
// off < rcache->off + rcache->size) {
// if (off >= rcache->off) {
// // is already in rcache?
// diff = lfs_min(diff, rcache->size - (off-rcache->off));
// memcpy(data, &rcache->buffer[off-rcache->off], diff);
//
// data += diff;
// off += diff;
// size -= diff;
// continue;
// }
//
// // rcache takes priority
// diff = lfs_min(diff, rcache->off-off);
// }
//
// // load to cache, first condition can no longer fail
// rcache->block = LFS_BLOCK_INLINE;
// rcache->off = lfs_aligndown(off, lfs->cfg->read_size);
// rcache->size = lfs_min(lfs_alignup(off+hint, lfs->cfg->read_size),
// lfs->cfg->cache_size);
// int err = lfs_dir_getslice(lfs, dir, gmask, gtag,
// rcache->off, rcache->buffer, rcache->size);
// if (err < 0) {
// return err;
// }
// }
//
// return 0;
//}
//
//#ifndef LFS_READONLY
//static int lfs_dir_traverse_filter(void *p,
// lfs_tag_t tag, const void *buffer) {
// lfs_tag_t *filtertag = p;
// (void)buffer;
//
// // which mask depends on unique bit in tag structure
// uint32_t mask = (tag & LFS_MKTAG(0x100, 0, 0))
// ? LFS_MKTAG(0x7ff, 0x3ff, 0)
// : LFS_MKTAG(0x700, 0x3ff, 0);
//
// // check for redundancy
// if ((mask & tag) == (mask & *filtertag) ||
// lfs_tag_isdelete(*filtertag) ||
// (LFS_MKTAG(0x7ff, 0x3ff, 0) & tag) == (
// LFS_MKTAG(LFS_TYPE_DELETE, 0, 0) |
// (LFS_MKTAG(0, 0x3ff, 0) & *filtertag))) {
// *filtertag = LFS_MKTAG(LFS_FROM_NOOP, 0, 0);
// return true;
// }
//
// // check if we need to adjust for created/deleted tags
// if (lfs_tag_type1(tag) == LFS_TYPE_SPLICE &&
// lfs_tag_id(tag) <= lfs_tag_id(*filtertag)) {
// *filtertag += LFS_MKTAG(0, lfs_tag_splice(tag), 0);
// }
//
// return false;
//}
//#endif
//
//#ifndef LFS_READONLY
//// maximum recursive depth of lfs_dir_traverse, the deepest call:
////
//// traverse with commit
//// '-> traverse with move
//// '-> traverse with filter
////
//#define LFS_DIR_TRAVERSE_DEPTH 3
//
//struct lfs_dir_traverse {
// const lfs_mdir_t *dir;
// lfs_off_t off;
// lfs_tag_t ptag;
// const struct lfs_mattr *attrs;
// int attrcount;
//
// lfs_tag_t tmask;
// lfs_tag_t ttag;
// uint16_t begin;
// uint16_t end;
// int16_t diff;
//
// int (*cb)(void *data, lfs_tag_t tag, const void *buffer);
// void *data;
//
// lfs_tag_t tag;
// const void *buffer;
// struct lfs_diskoff disk;
//};
//
//static int lfs_dir_traverse(lfs_t *lfs,
// const lfs_mdir_t *dir, lfs_off_t off, lfs_tag_t ptag,
// const struct lfs_mattr *attrs, int attrcount,
// lfs_tag_t tmask, lfs_tag_t ttag,
// uint16_t begin, uint16_t end, int16_t diff,
// int (*cb)(void *data, lfs_tag_t tag, const void *buffer), void *data) {
// // This function in inherently recursive, but bounded. To allow tool-based
// // analysis without unnecessary code-cost we use an explicit stack
// struct lfs_dir_traverse stack[LFS_DIR_TRAVERSE_DEPTH-1];
// unsigned sp = 0;
// int res;
//
// // iterate over directory and attrs
// lfs_tag_t tag;
// const void *buffer;
// struct lfs_diskoff disk;
// while (true) {
// {
// if (off+lfs_tag_dsize(ptag) < dir->off) {
// off += lfs_tag_dsize(ptag);
// int err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, sizeof(tag),
// dir->pair[0], off, &tag, sizeof(tag));
// if (err) {
// return err;
// }
//
// tag = (lfs_frombe32(tag) ^ ptag) | 0x80000000;
// disk.block = dir->pair[0];
// disk.off = off+sizeof(lfs_tag_t);
// buffer = &disk;
// ptag = tag;
// } else if (attrcount > 0) {
// tag = attrs[0].tag;
// buffer = attrs[0].buffer;
// attrs += 1;
// attrcount -= 1;
// } else {
// // finished traversal, pop from stack?
// res = 0;
// break;
// }
//
// // do we need to filter?
// lfs_tag_t mask = LFS_MKTAG(0x7ff, 0, 0);
// if ((mask & tmask & tag) != (mask & tmask & ttag)) {
// continue;
// }
//
// if (lfs_tag_id(tmask) != 0) {
// LFS_ASSERT(sp < LFS_DIR_TRAVERSE_DEPTH);
// // recurse, scan for duplicates, and update tag based on
// // creates/deletes
// stack[sp] = (struct lfs_dir_traverse){
// .dir = dir,
// .off = off,
// .ptag = ptag,
// .attrs = attrs,
// .attrcount = attrcount,
// .tmask = tmask,
// .ttag = ttag,
// .begin = begin,
// .end = end,
// .diff = diff,
// .cb = cb,
// .data = data,
// .tag = tag,
// .buffer = buffer,
// .disk = disk,
// };
// sp += 1;
//
// tmask = 0;
// ttag = 0;
// begin = 0;
// end = 0;
// diff = 0;
// cb = lfs_dir_traverse_filter;
// data = &stack[sp-1].tag;
// continue;
// }
// }
//
//popped:
// // in filter range?
// if (lfs_tag_id(tmask) != 0 &&
// !(lfs_tag_id(tag) >= begin && lfs_tag_id(tag) < end)) {
// continue;
// }
//
// // handle special cases for mcu-side operations
// if (lfs_tag_type3(tag) == LFS_FROM_NOOP) {
// // do nothing
// } else if (lfs_tag_type3(tag) == LFS_FROM_MOVE) {
// // Without this condition, lfs_dir_traverse can exhibit an
// // extremely expensive O(n^3) of nested loops when renaming.
// // This happens because lfs_dir_traverse tries to filter tags by
// // the tags in the source directory, triggering a second
// // lfs_dir_traverse with its own filter operation.
// //
// // traverse with commit
// // '-> traverse with filter
// // '-> traverse with move
// // '-> traverse with filter
// //
// // However we don't actually care about filtering the second set of
// // tags, since duplicate tags have no effect when filtering.
// //
// // This check skips this unnecessary recursive filtering explicitly,
// // reducing this runtime from O(n^3) to O(n^2).
// if (cb == lfs_dir_traverse_filter) {
// continue;
// }
//
// // recurse into move
// stack[sp] = (struct lfs_dir_traverse){
// .dir = dir,
// .off = off,
// .ptag = ptag,
// .attrs = attrs,
// .attrcount = attrcount,
// .tmask = tmask,
// .ttag = ttag,
// .begin = begin,
// .end = end,
// .diff = diff,
// .cb = cb,
// .data = data,
// .tag = LFS_MKTAG(LFS_FROM_NOOP, 0, 0),
// };
// sp += 1;
//
// uint16_t fromid = lfs_tag_size(tag);
// uint16_t toid = lfs_tag_id(tag);
// dir = buffer;
// off = 0;
// ptag = 0xffffffff;
// attrs = NULL;
// attrcount = 0;
// tmask = LFS_MKTAG(0x600, 0x3ff, 0);
// ttag = LFS_MKTAG(LFS_TYPE_STRUCT, 0, 0);
// begin = fromid;
// end = fromid+1;
// diff = toid-fromid+diff;
// } else if (lfs_tag_type3(tag) == LFS_FROM_USERATTRS) {
// for (unsigned i = 0; i < lfs_tag_size(tag); i++) {
// const struct lfs_attr *a = buffer;
// res = cb(data, LFS_MKTAG(LFS_TYPE_USERATTR + a[i].type,
// lfs_tag_id(tag) + diff, a[i].size), a[i].buffer);
// if (res < 0) {
// return res;
// }
//
// if (res) {
// break;
// }
// }
// } else {
// res = cb(data, tag + LFS_MKTAG(0, diff, 0), buffer);
// if (res < 0) {
// return res;
// }
//
// if (res) {
// break;
// }
// }
// }
//
// if (sp > 0) {
// // pop from the stack and return, fortunately all pops share
// // a destination
// dir = stack[sp-1].dir;
// off = stack[sp-1].off;
// ptag = stack[sp-1].ptag;
// attrs = stack[sp-1].attrs;
// attrcount = stack[sp-1].attrcount;
// tmask = stack[sp-1].tmask;
// ttag = stack[sp-1].ttag;
// begin = stack[sp-1].begin;
// end = stack[sp-1].end;
// diff = stack[sp-1].diff;
// cb = stack[sp-1].cb;
// data = stack[sp-1].data;
// tag = stack[sp-1].tag;
// buffer = stack[sp-1].buffer;
// disk = stack[sp-1].disk;
// sp -= 1;
// goto popped;
// } else {
// return res;
// }
//}
//#endif
//
//static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
// lfs_mdir_t *dir, const lfs_block_t pair[2],
// lfs_tag_t fmask, lfs_tag_t ftag, uint16_t *id,
// int (*cb)(void *data, lfs_tag_t tag, const void *buffer), void *data) {
// // we can find tag very efficiently during a fetch, since we're already
// // scanning the entire directory
// lfs_stag_t besttag = -1;
//
// // if either block address is invalid we return LFS_ERR_CORRUPT here,
// // otherwise later writes to the pair could fail
// if (pair[0] >= lfs->cfg->block_count || pair[1] >= lfs->cfg->block_count) {
// return LFS_ERR_CORRUPT;
// }
//
// // find the block with the most recent revision
// uint32_t revs[2] = {0, 0};
// int r = 0;
// for (int i = 0; i < 2; i++) {
// int err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, sizeof(revs[i]),
// pair[i], 0, &revs[i], sizeof(revs[i]));
// revs[i] = lfs_fromle32(revs[i]);
// if (err && err != LFS_ERR_CORRUPT) {
// return err;
// }
//
// if (err != LFS_ERR_CORRUPT &&
// lfs_scmp(revs[i], revs[(i+1)%2]) > 0) {
// r = i;
// }
// }
//
// dir->pair[0] = pair[(r+0)%2];
// dir->pair[1] = pair[(r+1)%2];
// dir->rev = revs[(r+0)%2];
// dir->off = 0; // nonzero = found some commits
//
// // now scan tags to fetch the actual dir and find possible match
// for (int i = 0; i < 2; i++) {
// lfs_off_t off = 0;
// lfs_tag_t ptag = 0xffffffff;
//
// uint16_t tempcount = 0;
// lfs_block_t temptail[2] = {LFS_BLOCK_NULL, LFS_BLOCK_NULL};
// bool tempsplit = false;
// lfs_stag_t tempbesttag = besttag;
//
// // assume not erased until proven otherwise
// bool maybeerased = false;
// bool hasfcrc = false;
// struct lfs_fcrc fcrc;
//
// dir->rev = lfs_tole32(dir->rev);
// uint32_t crc = lfs_crc(0xffffffff, &dir->rev, sizeof(dir->rev));
// dir->rev = lfs_fromle32(dir->rev);
//
// while (true) {
// // extract next tag
// lfs_tag_t tag;
// off += lfs_tag_dsize(ptag);
// int err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, lfs->cfg->block_size,
// dir->pair[0], off, &tag, sizeof(tag));
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// // can't continue?
// break;
// }
// return err;
// }
//
// crc = lfs_crc(crc, &tag, sizeof(tag));
// tag = lfs_frombe32(tag) ^ ptag;
//
// // next commit not yet programmed?
// if (!lfs_tag_isvalid(tag)) {
// maybeerased = true;
// break;
// // out of range?
// } else if (off + lfs_tag_dsize(tag) > lfs->cfg->block_size) {
// break;
// }
//
// ptag = tag;
//
// if (lfs_tag_type2(tag) == LFS_TYPE_CCRC) {
// // check the crc attr
// uint32_t dcrc;
// err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, lfs->cfg->block_size,
// dir->pair[0], off+sizeof(tag), &dcrc, sizeof(dcrc));
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// break;
// }
// return err;
// }
// dcrc = lfs_fromle32(dcrc);
//
// if (crc != dcrc) {
// break;
// }
//
// // reset the next bit if we need to
// ptag ^= (lfs_tag_t)(lfs_tag_chunk(tag) & 1U) << 31;
//
// // toss our crc into the filesystem seed for
// // pseudorandom numbers, note we use another crc here
// // as a collection function because it is sufficiently
// // random and convenient
// lfs->seed = lfs_crc(lfs->seed, &crc, sizeof(crc));
//
// // update with what's found so far
// besttag = tempbesttag;
// dir->off = off + lfs_tag_dsize(tag);
// dir->etag = ptag;
// dir->count = tempcount;
// dir->tail[0] = temptail[0];
// dir->tail[1] = temptail[1];
// dir->split = tempsplit;
//
// // reset crc
// crc = 0xffffffff;
// continue;
// }
//
// // fcrc is only valid when last tag was a crc
// hasfcrc = false;
//
// // crc the entry first, hopefully leaving it in the cache
// err = lfs_bd_crc(lfs,
// NULL, &lfs->rcache, lfs->cfg->block_size,
// dir->pair[0], off+sizeof(tag),
// lfs_tag_dsize(tag)-sizeof(tag), &crc);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// break;
// }
// return err;
// }
//
// // directory modification tags?
// if (lfs_tag_type1(tag) == LFS_TYPE_NAME) {
// // increase count of files if necessary
// if (lfs_tag_id(tag) >= tempcount) {
// tempcount = lfs_tag_id(tag) + 1;
// }
// } else if (lfs_tag_type1(tag) == LFS_TYPE_SPLICE) {
// tempcount += lfs_tag_splice(tag);
//
// if (tag == (LFS_MKTAG(LFS_TYPE_DELETE, 0, 0) |
// (LFS_MKTAG(0, 0x3ff, 0) & tempbesttag))) {
// tempbesttag |= 0x80000000;
// } else if (tempbesttag != -1 &&
// lfs_tag_id(tag) <= lfs_tag_id(tempbesttag)) {
// tempbesttag += LFS_MKTAG(0, lfs_tag_splice(tag), 0);
// }
// } else if (lfs_tag_type1(tag) == LFS_TYPE_TAIL) {
// tempsplit = (lfs_tag_chunk(tag) & 1);
//
// err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, lfs->cfg->block_size,
// dir->pair[0], off+sizeof(tag), &temptail, 8);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// break;
// }
// return err;
// }
// lfs_pair_fromle32(temptail);
// } else if (lfs_tag_type3(tag) == LFS_TYPE_FCRC) {
// err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, lfs->cfg->block_size,
// dir->pair[0], off+sizeof(tag),
// &fcrc, sizeof(fcrc));
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// break;
// }
// }
//
// lfs_fcrc_fromle32(&fcrc);
// hasfcrc = true;
// }
//
// // found a match for our fetcher?
// if ((fmask & tag) == (fmask & ftag)) {
// int res = cb(data, tag, &(struct lfs_diskoff){
// dir->pair[0], off+sizeof(tag)});
// if (res < 0) {
// if (res == LFS_ERR_CORRUPT) {
// break;
// }
// return res;
// }
//
// if (res == LFS_CMP_EQ) {
// // found a match
// tempbesttag = tag;
// } else if ((LFS_MKTAG(0x7ff, 0x3ff, 0) & tag) ==
// (LFS_MKTAG(0x7ff, 0x3ff, 0) & tempbesttag)) {
// // found an identical tag, but contents didn't match
// // this must mean that our besttag has been overwritten
// tempbesttag = -1;
// } else if (res == LFS_CMP_GT &&
// lfs_tag_id(tag) <= lfs_tag_id(tempbesttag)) {
// // found a greater match, keep track to keep things sorted
// tempbesttag = tag | 0x80000000;
// }
// }
// }
//
// // found no valid commits?
// if (dir->off == 0) {
// // try the other block?
// lfs_pair_swap(dir->pair);
// dir->rev = revs[(r+1)%2];
// continue;
// }
//
// // did we end on a valid commit? we may have an erased block
// dir->erased = false;
// if (maybeerased && hasfcrc && dir->off % lfs->cfg->prog_size == 0) {
// // check for an fcrc matching the next prog's erased state, if
// // this failed most likely a previous prog was interrupted, we
// // need a new erase
// uint32_t fcrc_ = 0xffffffff;
// int err = lfs_bd_crc(lfs,
// NULL, &lfs->rcache, lfs->cfg->block_size,
// dir->pair[0], dir->off, fcrc.size, &fcrc_);
// if (err && err != LFS_ERR_CORRUPT) {
// return err;
// }
//
// // found beginning of erased part?
// dir->erased = (fcrc_ == fcrc.crc);
// }
//
// // synthetic move
// if (lfs_gstate_hasmovehere(&lfs->gdisk, dir->pair)) {
// if (lfs_tag_id(lfs->gdisk.tag) == lfs_tag_id(besttag)) {
// besttag |= 0x80000000;
// } else if (besttag != -1 &&
// lfs_tag_id(lfs->gdisk.tag) < lfs_tag_id(besttag)) {
// besttag -= LFS_MKTAG(0, 1, 0);
// }
// }
//
// // found tag? or found best id?
// if (id) {
// *id = lfs_min(lfs_tag_id(besttag), dir->count);
// }
//
// if (lfs_tag_isvalid(besttag)) {
// return besttag;
// } else if (lfs_tag_id(besttag) < dir->count) {
// return LFS_ERR_NOENT;
// } else {
// return 0;
// }
// }
//
// LFS_ERROR("Corrupted dir pair at {0x%"PRIx32", 0x%"PRIx32"}",
// dir->pair[0], dir->pair[1]);
// return LFS_ERR_CORRUPT;
//}
//
//static int lfs_dir_fetch(lfs_t *lfs,
// lfs_mdir_t *dir, const lfs_block_t pair[2]) {
// // note, mask=-1, tag=-1 can never match a tag since this
// // pattern has the invalid bit set
// return (int)lfs_dir_fetchmatch(lfs, dir, pair,
// (lfs_tag_t)-1, (lfs_tag_t)-1, NULL, NULL, NULL);
//}
//
//static int lfs_dir_getgstate(lfs_t *lfs, const lfs_mdir_t *dir,
// lfs_gstate_t *gstate) {
// lfs_gstate_t temp;
// lfs_stag_t res = lfs_dir_get(lfs, dir, LFS_MKTAG(0x7ff, 0, 0),
// LFS_MKTAG(LFS_TYPE_MOVESTATE, 0, sizeof(temp)), &temp);
// if (res < 0 && res != LFS_ERR_NOENT) {
// return res;
// }
//
// if (res != LFS_ERR_NOENT) {
// // xor together to find resulting gstate
// lfs_gstate_fromle32(&temp);
// lfs_gstate_xor(gstate, &temp);
// }
//
// return 0;
//}
//
//static int lfs_dir_getinfo(lfs_t *lfs, lfs_mdir_t *dir,
// uint16_t id, struct lfs_info *info) {
// if (id == 0x3ff) {
// // special case for root
// strcpy(info->name, "/");
// info->type = LFS_TYPE_DIR;
// return 0;
// }
//
// lfs_stag_t tag = lfs_dir_get(lfs, dir, LFS_MKTAG(0x780, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_NAME, id, lfs->name_max+1), info->name);
// if (tag < 0) {
// return (int)tag;
// }
//
// info->type = lfs_tag_type3(tag);
//
// struct lfs_ctz ctz;
// tag = lfs_dir_get(lfs, dir, LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, id, sizeof(ctz)), &ctz);
// if (tag < 0) {
// return (int)tag;
// }
// lfs_ctz_fromle32(&ctz);
//
// if (lfs_tag_type3(tag) == LFS_TYPE_CTZSTRUCT) {
// info->size = ctz.size;
// } else if (lfs_tag_type3(tag) == LFS_TYPE_INLINESTRUCT) {
// info->size = lfs_tag_size(tag);
// }
//
// return 0;
//}
//
//struct lfs_dir_find_match {
// lfs_t *lfs;
// const void *name;
// lfs_size_t size;
//};
//
//static int lfs_dir_find_match(void *data,
// lfs_tag_t tag, const void *buffer) {
// struct lfs_dir_find_match *name = data;
// lfs_t *lfs = name->lfs;
// const struct lfs_diskoff *disk = buffer;
//
// // compare with disk
// lfs_size_t diff = lfs_min(name->size, lfs_tag_size(tag));
// int res = lfs_bd_cmp(lfs,
// NULL, &lfs->rcache, diff,
// disk->block, disk->off, name->name, diff);
// if (res != LFS_CMP_EQ) {
// return res;
// }
//
// // only equal if our size is still the same
// if (name->size != lfs_tag_size(tag)) {
// return (name->size < lfs_tag_size(tag)) ? LFS_CMP_LT : LFS_CMP_GT;
// }
//
// // found a match!
// return LFS_CMP_EQ;
//}
//
//static lfs_stag_t lfs_dir_find(lfs_t *lfs, lfs_mdir_t *dir,
// const char **path, uint16_t *id) {
// // we reduce path to a single name if we can find it
// const char *name = *path;
// if (id) {
// *id = 0x3ff;
// }
//
// // default to root dir
// lfs_stag_t tag = LFS_MKTAG(LFS_TYPE_DIR, 0x3ff, 0);
// dir->tail[0] = lfs->root[0];
// dir->tail[1] = lfs->root[1];
//
// while (true) {
//nextname:
// // skip slashes
// name += strspn(name, "/");
// lfs_size_t namelen = strcspn(name, "/");
//
// // skip '.' and root '..'
// if ((namelen == 1 && memcmp(name, ".", 1) == 0) ||
// (namelen == 2 && memcmp(name, "..", 2) == 0)) {
// name += namelen;
// goto nextname;
// }
//
// // skip if matched by '..' in name
// const char *suffix = name + namelen;
// lfs_size_t sufflen;
// int depth = 1;
// while (true) {
// suffix += strspn(suffix, "/");
// sufflen = strcspn(suffix, "/");
// if (sufflen == 0) {
// break;
// }
//
// if (sufflen == 2 && memcmp(suffix, "..", 2) == 0) {
// depth -= 1;
// if (depth == 0) {
// name = suffix + sufflen;
// goto nextname;
// }
// } else {
// depth += 1;
// }
//
// suffix += sufflen;
// }
//
// // found path
// if (name[0] == '\0') {
// return tag;
// }
//
// // update what we've found so far
// *path = name;
//
// // only continue if we hit a directory
// if (lfs_tag_type3(tag) != LFS_TYPE_DIR) {
// return LFS_ERR_NOTDIR;
// }
//
// // grab the entry data
// if (lfs_tag_id(tag) != 0x3ff) {
// lfs_stag_t res = lfs_dir_get(lfs, dir, LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tag_id(tag), 8), dir->tail);
// if (res < 0) {
// return res;
// }
// lfs_pair_fromle32(dir->tail);
// }
//
// // find entry matching name
// while (true) {
// tag = lfs_dir_fetchmatch(lfs, dir, dir->tail,
// LFS_MKTAG(0x780, 0, 0),
// LFS_MKTAG(LFS_TYPE_NAME, 0, namelen),
// // are we last name?
// (strchr(name, '/') == NULL) ? id : NULL,
// lfs_dir_find_match, &(struct lfs_dir_find_match){
// lfs, name, namelen});
// if (tag < 0) {
// return tag;
// }
//
// if (tag) {
// break;
// }
//
// if (!dir->split) {
// return LFS_ERR_NOENT;
// }
// }
//
// // to next name
// name += namelen;
// }
//}
//
//// commit logic
//struct lfs_commit {
// lfs_block_t block;
// lfs_off_t off;
// lfs_tag_t ptag;
// uint32_t crc;
//
// lfs_off_t begin;
// lfs_off_t end;
//};
//
//#ifndef LFS_READONLY
//static int lfs_dir_commitprog(lfs_t *lfs, struct lfs_commit *commit,
// const void *buffer, lfs_size_t size) {
// int err = lfs_bd_prog(lfs,
// &lfs->pcache, &lfs->rcache, false,
// commit->block, commit->off ,
// (const uint8_t*)buffer, size);
// if (err) {
// return err;
// }
//
// commit->crc = lfs_crc(commit->crc, buffer, size);
// commit->off += size;
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_commitattr(lfs_t *lfs, struct lfs_commit *commit,
// lfs_tag_t tag, const void *buffer) {
// // check if we fit
// lfs_size_t dsize = lfs_tag_dsize(tag);
// if (commit->off + dsize > commit->end) {
// return LFS_ERR_NOSPC;
// }
//
// // write out tag
// lfs_tag_t ntag = lfs_tobe32((tag & 0x7fffffff) ^ commit->ptag);
// int err = lfs_dir_commitprog(lfs, commit, &ntag, sizeof(ntag));
// if (err) {
// return err;
// }
//
// if (!(tag & 0x80000000)) {
// // from memory
// err = lfs_dir_commitprog(lfs, commit, buffer, dsize-sizeof(tag));
// if (err) {
// return err;
// }
// } else {
// // from disk
// const struct lfs_diskoff *disk = buffer;
// for (lfs_off_t i = 0; i < dsize-sizeof(tag); i++) {
// // rely on caching to make this efficient
// uint8_t dat;
// err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, dsize-sizeof(tag)-i,
// disk->block, disk->off+i, &dat, 1);
// if (err) {
// return err;
// }
//
// err = lfs_dir_commitprog(lfs, commit, &dat, 1);
// if (err) {
// return err;
// }
// }
// }
//
// commit->ptag = tag & 0x7fffffff;
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//
//static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
// // align to program units
// //
// // this gets a bit complex as we have two types of crcs:
// // - 5-word crc with fcrc to check following prog (middle of block)
// // - 2-word crc with no following prog (end of block)
// const lfs_off_t end = lfs_alignup(
// lfs_min(commit->off + 5*sizeof(uint32_t), lfs->cfg->block_size),
// lfs->cfg->prog_size);
//
// lfs_off_t off1 = 0;
// uint32_t crc1 = 0;
//
// // create crc tags to fill up remainder of commit, note that
// // padding is not crced, which lets fetches skip padding but
// // makes committing a bit more complicated
// while (commit->off < end) {
// lfs_off_t noff = (
// lfs_min(end - (commit->off+sizeof(lfs_tag_t)), 0x3fe)
// + (commit->off+sizeof(lfs_tag_t)));
// // too large for crc tag? need padding commits
// if (noff < end) {
// noff = lfs_min(noff, end - 5*sizeof(uint32_t));
// }
//
// // space for fcrc?
// uint8_t eperturb = -1;
// if (noff >= end && noff <= lfs->cfg->block_size - lfs->cfg->prog_size) {
// // first read the leading byte, this always contains a bit
// // we can perturb to avoid writes that don't change the fcrc
// int err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, lfs->cfg->prog_size,
// commit->block, noff, &eperturb, 1);
// if (err && err != LFS_ERR_CORRUPT) {
// return err;
// }
//
// // find the expected fcrc, don't bother avoiding a reread
// // of the eperturb, it should still be in our cache
// struct lfs_fcrc fcrc = {.size=lfs->cfg->prog_size, .crc=0xffffffff};
// err = lfs_bd_crc(lfs,
// NULL, &lfs->rcache, lfs->cfg->prog_size,
// commit->block, noff, fcrc.size, &fcrc.crc);
// if (err && err != LFS_ERR_CORRUPT) {
// return err;
// }
//
// lfs_fcrc_tole32(&fcrc);
// err = lfs_dir_commitattr(lfs, commit,
// LFS_MKTAG(LFS_TYPE_FCRC, 0x3ff, sizeof(struct lfs_fcrc)),
// &fcrc);
// if (err) {
// return err;
// }
// }
//
// // build commit crc
// struct {
// lfs_tag_t tag;
// uint32_t crc;
// } ccrc;
// lfs_tag_t ntag = LFS_MKTAG(
// LFS_TYPE_CCRC + (((uint8_t)~eperturb) >> 7), 0x3ff,
// noff - (commit->off+sizeof(lfs_tag_t)));
// ccrc.tag = lfs_tobe32(ntag ^ commit->ptag);
// commit->crc = lfs_crc(commit->crc, &ccrc.tag, sizeof(lfs_tag_t));
// ccrc.crc = lfs_tole32(commit->crc);
//
// int err = lfs_bd_prog(lfs,
// &lfs->pcache, &lfs->rcache, false,
// commit->block, commit->off, &ccrc, sizeof(ccrc));
// if (err) {
// return err;
// }
//
// // keep track of non-padding checksum to verify
// if (off1 == 0) {
// off1 = commit->off + sizeof(lfs_tag_t);
// crc1 = commit->crc;
// }
//
// commit->off = noff;
// // perturb valid bit?
// commit->ptag = ntag ^ ((0x80 & ~eperturb) << 24);
// // reset crc for next commit
// commit->crc = 0xffffffff;
//
// // manually flush here since we don't prog the padding, this confuses
// // the caching layer
// if (noff >= end || noff >= lfs->pcache.off + lfs->cfg->cache_size) {
// // flush buffers
// int err = lfs_bd_sync(lfs, &lfs->pcache, &lfs->rcache, false);
// if (err) {
// return err;
// }
// }
// }
//
// // successful commit, check checksums to make sure
// //
// // note that we don't need to check padding commits, worst
// // case if they are corrupted we would have had to compact anyways
// lfs_off_t off = commit->begin;
// uint32_t crc = 0xffffffff;
// int err = lfs_bd_crc(lfs,
// NULL, &lfs->rcache, off1+sizeof(uint32_t),
// commit->block, off, off1-off, &crc);
// if (err) {
// return err;
// }
//
// // check non-padding commits against known crc
// if (crc != crc1) {
// return LFS_ERR_CORRUPT;
// }
//
// // make sure to check crc in case we happen to pick
// // up an unrelated crc (frozen block?)
// err = lfs_bd_crc(lfs,
// NULL, &lfs->rcache, sizeof(uint32_t),
// commit->block, off1, sizeof(uint32_t), &crc);
// if (err) {
// return err;
// }
//
// if (crc != 0) {
// return LFS_ERR_CORRUPT;
// }
//
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_alloc(lfs_t *lfs, lfs_mdir_t *dir) {
// // allocate pair of dir blocks (backwards, so we write block 1 first)
// for (int i = 0; i < 2; i++) {
// int err = lfs_alloc(lfs, &dir->pair[(i+1)%2]);
// if (err) {
// return err;
// }
// }
//
// // zero for reproducibility in case initial block is unreadable
// dir->rev = 0;
//
// // rather than clobbering one of the blocks we just pretend
// // the revision may be valid
// int err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, sizeof(dir->rev),
// dir->pair[0], 0, &dir->rev, sizeof(dir->rev));
// dir->rev = lfs_fromle32(dir->rev);
// if (err && err != LFS_ERR_CORRUPT) {
// return err;
// }
//
// // to make sure we don't immediately evict, align the new revision count
// // to our block_cycles modulus, see lfs_dir_compact for why our modulus
// // is tweaked this way
// if (lfs->cfg->block_cycles > 0) {
// dir->rev = lfs_alignup(dir->rev, ((lfs->cfg->block_cycles+1)|1));
// }
//
// // set defaults
// dir->off = sizeof(dir->rev);
// dir->etag = 0xffffffff;
// dir->count = 0;
// dir->tail[0] = LFS_BLOCK_NULL;
// dir->tail[1] = LFS_BLOCK_NULL;
// dir->erased = false;
// dir->split = false;
//
// // don't write out yet, let caller take care of that
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_drop(lfs_t *lfs, lfs_mdir_t *dir, lfs_mdir_t *tail) {
// // steal state
// int err = lfs_dir_getgstate(lfs, tail, &lfs->gdelta);
// if (err) {
// return err;
// }
//
// // steal tail
// lfs_pair_tole32(tail->tail);
// err = lfs_dir_commit(lfs, dir, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_TAIL + tail->split, 0x3ff, 8), tail->tail}));
// lfs_pair_fromle32(tail->tail);
// if (err) {
// return err;
// }
//
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_split(lfs_t *lfs,
// lfs_mdir_t *dir, const struct lfs_mattr *attrs, int attrcount,
// lfs_mdir_t *source, uint16_t split, uint16_t end) {
// // create tail metadata pair
// lfs_mdir_t tail;
// int err = lfs_dir_alloc(lfs, &tail);
// if (err) {
// return err;
// }
//
// tail.split = dir->split;
// tail.tail[0] = dir->tail[0];
// tail.tail[1] = dir->tail[1];
//
// // note we don't care about LFS_OK_RELOCATED
// int res = lfs_dir_compact(lfs, &tail, attrs, attrcount, source, split, end);
// if (res < 0) {
// return res;
// }
//
// dir->tail[0] = tail.pair[0];
// dir->tail[1] = tail.pair[1];
// dir->split = true;
//
// // update root if needed
// if (lfs_pair_cmp(dir->pair, lfs->root) == 0 && split == 0) {
// lfs->root[0] = tail.pair[0];
// lfs->root[1] = tail.pair[1];
// }
//
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_commit_size(void *p, lfs_tag_t tag, const void *buffer) {
// lfs_size_t *size = p;
// (void)buffer;
//
// *size += lfs_tag_dsize(tag);
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//struct lfs_dir_commit_commit {
// lfs_t *lfs;
// struct lfs_commit *commit;
//};
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_commit_commit(void *p, lfs_tag_t tag, const void *buffer) {
// struct lfs_dir_commit_commit *commit = p;
// return lfs_dir_commitattr(commit->lfs, commit->commit, tag, buffer);
//}
//#endif
//
//#ifndef LFS_READONLY
//static bool lfs_dir_needsrelocation(lfs_t *lfs, lfs_mdir_t *dir) {
// // If our revision count == n * block_cycles, we should force a relocation,
// // this is how littlefs wear-levels at the metadata-pair level. Note that we
// // actually use (block_cycles+1)|1, this is to avoid two corner cases:
// // 1. block_cycles = 1, which would prevent relocations from terminating
// // 2. block_cycles = 2n, which, due to aliasing, would only ever relocate
// // one metadata block in the pair, effectively making this useless
// return (lfs->cfg->block_cycles > 0
// && ((dir->rev + 1) % ((lfs->cfg->block_cycles+1)|1) == 0));
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_compact(lfs_t *lfs,
// lfs_mdir_t *dir, const struct lfs_mattr *attrs, int attrcount,
// lfs_mdir_t *source, uint16_t begin, uint16_t end) {
// // save some state in case block is bad
// bool relocated = false;
// bool tired = lfs_dir_needsrelocation(lfs, dir);
//
// // increment revision count
// dir->rev += 1;
//
// // do not proactively relocate blocks during migrations, this
// // can cause a number of failure states such: clobbering the
// // v1 superblock if we relocate root, and invalidating directory
// // pointers if we relocate the head of a directory. On top of
// // this, relocations increase the overall complexity of
// // lfs_migration, which is already a delicate operation.
//#ifdef LFS_MIGRATE
// if (lfs->lfs1) {
// tired = false;
// }
//#endif
//
// if (tired && lfs_pair_cmp(dir->pair, (const lfs_block_t[2]){0, 1}) != 0) {
// // we're writing too much, time to relocate
// goto relocate;
// }
//
// // begin loop to commit compaction to blocks until a compact sticks
// while (true) {
// {
// // setup commit state
// struct lfs_commit commit = {
// .block = dir->pair[1],
// .off = 0,
// .ptag = 0xffffffff,
// .crc = 0xffffffff,
//
// .begin = 0,
// .end = (lfs->cfg->metadata_max ?
// lfs->cfg->metadata_max : lfs->cfg->block_size) - 8,
// };
//
// // erase block to write to
// int err = lfs_bd_erase(lfs, dir->pair[1]);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// // write out header
// dir->rev = lfs_tole32(dir->rev);
// err = lfs_dir_commitprog(lfs, &commit,
// &dir->rev, sizeof(dir->rev));
// dir->rev = lfs_fromle32(dir->rev);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// // traverse the directory, this time writing out all unique tags
// err = lfs_dir_traverse(lfs,
// source, 0, 0xffffffff, attrs, attrcount,
// LFS_MKTAG(0x400, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_NAME, 0, 0),
// begin, end, -begin,
// lfs_dir_commit_commit, &(struct lfs_dir_commit_commit){
// lfs, &commit});
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// // commit tail, which may be new after last size check
// if (!lfs_pair_isnull(dir->tail)) {
// lfs_pair_tole32(dir->tail);
// err = lfs_dir_commitattr(lfs, &commit,
// LFS_MKTAG(LFS_TYPE_TAIL + dir->split, 0x3ff, 8),
// dir->tail);
// lfs_pair_fromle32(dir->tail);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
// }
//
// // bring over gstate?
// lfs_gstate_t delta = {0};
// if (!relocated) {
// lfs_gstate_xor(&delta, &lfs->gdisk);
// lfs_gstate_xor(&delta, &lfs->gstate);
// }
// lfs_gstate_xor(&delta, &lfs->gdelta);
// delta.tag &= ~LFS_MKTAG(0, 0, 0x3ff);
//
// err = lfs_dir_getgstate(lfs, dir, &delta);
// if (err) {
// return err;
// }
//
// if (!lfs_gstate_iszero(&delta)) {
// lfs_gstate_tole32(&delta);
// err = lfs_dir_commitattr(lfs, &commit,
// LFS_MKTAG(LFS_TYPE_MOVESTATE, 0x3ff,
// sizeof(delta)), &delta);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
// }
//
// // complete commit with crc
// err = lfs_dir_commitcrc(lfs, &commit);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// // successful compaction, swap dir pair to indicate most recent
// LFS_ASSERT(commit.off % lfs->cfg->prog_size == 0);
// lfs_pair_swap(dir->pair);
// dir->count = end - begin;
// dir->off = commit.off;
// dir->etag = commit.ptag;
// // update gstate
// lfs->gdelta = (lfs_gstate_t){0};
// if (!relocated) {
// lfs->gdisk = lfs->gstate;
// }
// }
// break;
//
//relocate:
// // commit was corrupted, drop caches and prepare to relocate block
// relocated = true;
// lfs_cache_drop(lfs, &lfs->pcache);
// if (!tired) {
// LFS_DEBUG("Bad block at 0x%"PRIx32, dir->pair[1]);
// }
//
// // can't relocate superblock, filesystem is now frozen
// if (lfs_pair_cmp(dir->pair, (const lfs_block_t[2]){0, 1}) == 0) {
// LFS_WARN("Superblock 0x%"PRIx32" has become unwritable",
// dir->pair[1]);
// return LFS_ERR_NOSPC;
// }
//
// // relocate half of pair
// int err = lfs_alloc(lfs, &dir->pair[1]);
// if (err && (err != LFS_ERR_NOSPC || !tired)) {
// return err;
// }
//
// tired = false;
// continue;
// }
//
// return relocated ? LFS_OK_RELOCATED : 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_splittingcompact(lfs_t *lfs, lfs_mdir_t *dir,
// const struct lfs_mattr *attrs, int attrcount,
// lfs_mdir_t *source, uint16_t begin, uint16_t end) {
// while (true) {
// // find size of first split, we do this by halving the split until
// // the metadata is guaranteed to fit
// //
// // Note that this isn't a true binary search, we never increase the
// // split size. This may result in poorly distributed metadata but isn't
// // worth the extra code size or performance hit to fix.
// lfs_size_t split = begin;
// while (end - split > 1) {
// lfs_size_t size = 0;
// int err = lfs_dir_traverse(lfs,
// source, 0, 0xffffffff, attrs, attrcount,
// LFS_MKTAG(0x400, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_NAME, 0, 0),
// split, end, -split,
// lfs_dir_commit_size, &size);
// if (err) {
// return err;
// }
//
// // space is complicated, we need room for:
// //
// // - tail: 4+2*4 = 12 bytes
// // - gstate: 4+3*4 = 16 bytes
// // - move delete: 4 = 4 bytes
// // - crc: 4+4 = 8 bytes
// // total = 40 bytes
// //
// // And we cap at half a block to avoid degenerate cases with
// // nearly-full metadata blocks.
// //
// if (end - split < 0xff
// && size <= lfs_min(
// lfs->cfg->block_size - 40,
// lfs_alignup(
// (lfs->cfg->metadata_max
// ? lfs->cfg->metadata_max
// : lfs->cfg->block_size)/2,
// lfs->cfg->prog_size))) {
// break;
// }
//
// split = split + ((end - split) / 2);
// }
//
// if (split == begin) {
// // no split needed
// break;
// }
//
// // split into two metadata pairs and continue
// int err = lfs_dir_split(lfs, dir, attrs, attrcount,
// source, split, end);
// if (err && err != LFS_ERR_NOSPC) {
// return err;
// }
//
// if (err) {
// // we can't allocate a new block, try to compact with degraded
// // performance
// LFS_WARN("Unable to split {0x%"PRIx32", 0x%"PRIx32"}",
// dir->pair[0], dir->pair[1]);
// break;
// } else {
// end = split;
// }
// }
//
// if (lfs_dir_needsrelocation(lfs, dir)
// && lfs_pair_cmp(dir->pair, (const lfs_block_t[2]){0, 1}) == 0) {
// // oh no! we're writing too much to the superblock,
// // should we expand?
// lfs_ssize_t size = lfs_fs_rawsize(lfs);
// if (size < 0) {
// return size;
// }
//
// // do we have extra space? littlefs can't reclaim this space
// // by itself, so expand cautiously
// if ((lfs_size_t)size < lfs->cfg->block_count/2) {
// LFS_DEBUG("Expanding superblock at rev %"PRIu32, dir->rev);
// int err = lfs_dir_split(lfs, dir, attrs, attrcount,
// source, begin, end);
// if (err && err != LFS_ERR_NOSPC) {
// return err;
// }
//
// if (err) {
// // welp, we tried, if we ran out of space there's not much
// // we can do, we'll error later if we've become frozen
// LFS_WARN("Unable to expand superblock");
// } else {
// end = begin;
// }
// }
// }
//
// return lfs_dir_compact(lfs, dir, attrs, attrcount, source, begin, end);
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_relocatingcommit(lfs_t *lfs, lfs_mdir_t *dir,
// const lfs_block_t pair[2],
// const struct lfs_mattr *attrs, int attrcount,
// lfs_mdir_t *pdir) {
// int state = 0;
//
// // calculate changes to the directory
// bool hasdelete = false;
// for (int i = 0; i < attrcount; i++) {
// if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_CREATE) {
// dir->count += 1;
// } else if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_DELETE) {
// LFS_ASSERT(dir->count > 0);
// dir->count -= 1;
// hasdelete = true;
// } else if (lfs_tag_type1(attrs[i].tag) == LFS_TYPE_TAIL) {
// dir->tail[0] = ((lfs_block_t*)attrs[i].buffer)[0];
// dir->tail[1] = ((lfs_block_t*)attrs[i].buffer)[1];
// dir->split = (lfs_tag_chunk(attrs[i].tag) & 1);
// lfs_pair_fromle32(dir->tail);
// }
// }
//
// // should we actually drop the directory block?
// if (hasdelete && dir->count == 0) {
// LFS_ASSERT(pdir);
// int err = lfs_fs_pred(lfs, dir->pair, pdir);
// if (err && err != LFS_ERR_NOENT) {
// return err;
// }
//
// if (err != LFS_ERR_NOENT && pdir->split) {
// state = LFS_OK_DROPPED;
// goto fixmlist;
// }
// }
//
// if (dir->erased) {
// // try to commit
// struct lfs_commit commit = {
// .block = dir->pair[0],
// .off = dir->off,
// .ptag = dir->etag,
// .crc = 0xffffffff,
//
// .begin = dir->off,
// .end = (lfs->cfg->metadata_max ?
// lfs->cfg->metadata_max : lfs->cfg->block_size) - 8,
// };
//
// // traverse attrs that need to be written out
// lfs_pair_tole32(dir->tail);
// int err = lfs_dir_traverse(lfs,
// dir, dir->off, dir->etag, attrs, attrcount,
// 0, 0, 0, 0, 0,
// lfs_dir_commit_commit, &(struct lfs_dir_commit_commit){
// lfs, &commit});
// lfs_pair_fromle32(dir->tail);
// if (err) {
// if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
// goto compact;
// }
// return err;
// }
//
// // commit any global diffs if we have any
// lfs_gstate_t delta = {0};
// lfs_gstate_xor(&delta, &lfs->gstate);
// lfs_gstate_xor(&delta, &lfs->gdisk);
// lfs_gstate_xor(&delta, &lfs->gdelta);
// delta.tag &= ~LFS_MKTAG(0, 0, 0x3ff);
// if (!lfs_gstate_iszero(&delta)) {
// err = lfs_dir_getgstate(lfs, dir, &delta);
// if (err) {
// return err;
// }
//
// lfs_gstate_tole32(&delta);
// err = lfs_dir_commitattr(lfs, &commit,
// LFS_MKTAG(LFS_TYPE_MOVESTATE, 0x3ff,
// sizeof(delta)), &delta);
// if (err) {
// if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
// goto compact;
// }
// return err;
// }
// }
//
// // finalize commit with the crc
// err = lfs_dir_commitcrc(lfs, &commit);
// if (err) {
// if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
// goto compact;
// }
// return err;
// }
//
// // successful commit, update dir
// LFS_ASSERT(commit.off % lfs->cfg->prog_size == 0);
// dir->off = commit.off;
// dir->etag = commit.ptag;
// // and update gstate
// lfs->gdisk = lfs->gstate;
// lfs->gdelta = (lfs_gstate_t){0};
//
// goto fixmlist;
// }
//
//compact:
// // fall back to compaction
// lfs_cache_drop(lfs, &lfs->pcache);
//
// state = lfs_dir_splittingcompact(lfs, dir, attrs, attrcount,
// dir, 0, dir->count);
// if (state < 0) {
// return state;
// }
//
// goto fixmlist;
//
//fixmlist:;
// // this complicated bit of logic is for fixing up any active
// // metadata-pairs that we may have affected
// //
// // note we have to make two passes since the mdir passed to
// // lfs_dir_commit could also be in this list, and even then
// // we need to copy the pair so they don't get clobbered if we refetch
// // our mdir.
// lfs_block_t oldpair[2] = {pair[0], pair[1]};
// for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
// if (lfs_pair_cmp(d->m.pair, oldpair) == 0) {
// d->m = *dir;
// if (d->m.pair != pair) {
// for (int i = 0; i < attrcount; i++) {
// if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_DELETE &&
// d->id == lfs_tag_id(attrs[i].tag)) {
// d->m.pair[0] = LFS_BLOCK_NULL;
// d->m.pair[1] = LFS_BLOCK_NULL;
// } else if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_DELETE &&
// d->id > lfs_tag_id(attrs[i].tag)) {
// d->id -= 1;
// if (d->type == LFS_TYPE_DIR) {
// ((lfs_dir_t*)d)->pos -= 1;
// }
// } else if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_CREATE &&
// d->id >= lfs_tag_id(attrs[i].tag)) {
// d->id += 1;
// if (d->type == LFS_TYPE_DIR) {
// ((lfs_dir_t*)d)->pos += 1;
// }
// }
// }
// }
//
// while (d->id >= d->m.count && d->m.split) {
// // we split and id is on tail now
// d->id -= d->m.count;
// int err = lfs_dir_fetch(lfs, &d->m, d->m.tail);
// if (err) {
// return err;
// }
// }
// }
// }
//
// return state;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_orphaningcommit(lfs_t *lfs, lfs_mdir_t *dir,
// const struct lfs_mattr *attrs, int attrcount) {
// // check for any inline files that aren't RAM backed and
// // forcefully evict them, needed for filesystem consistency
// for (lfs_file_t *f = (lfs_file_t*)lfs->mlist; f; f = f->next) {
// if (dir != &f->m && lfs_pair_cmp(f->m.pair, dir->pair) == 0 &&
// f->type == LFS_TYPE_REG && (f->flags & LFS_F_INLINE) &&
// f->ctz.size > lfs->cfg->cache_size) {
// int err = lfs_file_outline(lfs, f);
// if (err) {
// return err;
// }
//
// err = lfs_file_flush(lfs, f);
// if (err) {
// return err;
// }
// }
// }
//
// lfs_block_t lpair[2] = {dir->pair[0], dir->pair[1]};
// lfs_mdir_t ldir = *dir;
// lfs_mdir_t pdir;
// int state = lfs_dir_relocatingcommit(lfs, &ldir, dir->pair,
// attrs, attrcount, &pdir);
// if (state < 0) {
// return state;
// }
//
// // update if we're not in mlist, note we may have already been
// // updated if we are in mlist
// if (lfs_pair_cmp(dir->pair, lpair) == 0) {
// *dir = ldir;
// }
//
// // commit was successful, but may require other changes in the
// // filesystem, these would normally be tail recursive, but we have
// // flattened them here avoid unbounded stack usage
//
// // need to drop?
// if (state == LFS_OK_DROPPED) {
// // steal state
// int err = lfs_dir_getgstate(lfs, dir, &lfs->gdelta);
// if (err) {
// return err;
// }
//
// // steal tail, note that this can't create a recursive drop
// lpair[0] = pdir.pair[0];
// lpair[1] = pdir.pair[1];
// lfs_pair_tole32(dir->tail);
// state = lfs_dir_relocatingcommit(lfs, &pdir, lpair, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_TAIL + dir->split, 0x3ff, 8),
// dir->tail}),
// NULL);
// lfs_pair_fromle32(dir->tail);
// if (state < 0) {
// return state;
// }
//
// ldir = pdir;
// }
//
// // need to relocate?
// bool orphans = false;
// while (state == LFS_OK_RELOCATED) {
// LFS_DEBUG("Relocating {0x%"PRIx32", 0x%"PRIx32"} "
// "-> {0x%"PRIx32", 0x%"PRIx32"}",
// lpair[0], lpair[1], ldir.pair[0], ldir.pair[1]);
// state = 0;
//
// // update internal root
// if (lfs_pair_cmp(lpair, lfs->root) == 0) {
// lfs->root[0] = ldir.pair[0];
// lfs->root[1] = ldir.pair[1];
// }
//
// // update internally tracked dirs
// for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
// if (lfs_pair_cmp(lpair, d->m.pair) == 0) {
// d->m.pair[0] = ldir.pair[0];
// d->m.pair[1] = ldir.pair[1];
// }
//
// if (d->type == LFS_TYPE_DIR &&
// lfs_pair_cmp(lpair, ((lfs_dir_t*)d)->head) == 0) {
// ((lfs_dir_t*)d)->head[0] = ldir.pair[0];
// ((lfs_dir_t*)d)->head[1] = ldir.pair[1];
// }
// }
//
// // find parent
// lfs_stag_t tag = lfs_fs_parent(lfs, lpair, &pdir);
// if (tag < 0 && tag != LFS_ERR_NOENT) {
// return tag;
// }
//
// bool hasparent = (tag != LFS_ERR_NOENT);
// if (tag != LFS_ERR_NOENT) {
// // note that if we have a parent, we must have a pred, so this will
// // always create an orphan
// int err = lfs_fs_preporphans(lfs, +1);
// if (err) {
// return err;
// }
//
// // fix pending move in this pair? this looks like an optimization but
// // is in fact _required_ since relocating may outdate the move.
// uint16_t moveid = 0x3ff;
// if (lfs_gstate_hasmovehere(&lfs->gstate, pdir.pair)) {
// moveid = lfs_tag_id(lfs->gstate.tag);
// LFS_DEBUG("Fixing move while relocating "
// "{0x%"PRIx32", 0x%"PRIx32"} 0x%"PRIx16"\n",
// pdir.pair[0], pdir.pair[1], moveid);
// lfs_fs_prepmove(lfs, 0x3ff, NULL);
// if (moveid < lfs_tag_id(tag)) {
// tag -= LFS_MKTAG(0, 1, 0);
// }
// }
//
// lfs_block_t ppair[2] = {pdir.pair[0], pdir.pair[1]};
// lfs_pair_tole32(ldir.pair);
// state = lfs_dir_relocatingcommit(lfs, &pdir, ppair, LFS_MKATTRS(
// {LFS_MKTAG_IF(moveid != 0x3ff,
// LFS_TYPE_DELETE, moveid, 0), NULL},
// {tag, ldir.pair}),
// NULL);
// lfs_pair_fromle32(ldir.pair);
// if (state < 0) {
// return state;
// }
//
// if (state == LFS_OK_RELOCATED) {
// lpair[0] = ppair[0];
// lpair[1] = ppair[1];
// ldir = pdir;
// orphans = true;
// continue;
// }
// }
//
// // find pred
// int err = lfs_fs_pred(lfs, lpair, &pdir);
// if (err && err != LFS_ERR_NOENT) {
// return err;
// }
// LFS_ASSERT(!(hasparent && err == LFS_ERR_NOENT));
//
// // if we can't find dir, it must be new
// if (err != LFS_ERR_NOENT) {
// if (lfs_gstate_hasorphans(&lfs->gstate)) {
// // next step, clean up orphans
// err = lfs_fs_preporphans(lfs, -hasparent);
// if (err) {
// return err;
// }
// }
//
// // fix pending move in this pair? this looks like an optimization
// // but is in fact _required_ since relocating may outdate the move.
// uint16_t moveid = 0x3ff;
// if (lfs_gstate_hasmovehere(&lfs->gstate, pdir.pair)) {
// moveid = lfs_tag_id(lfs->gstate.tag);
// LFS_DEBUG("Fixing move while relocating "
// "{0x%"PRIx32", 0x%"PRIx32"} 0x%"PRIx16"\n",
// pdir.pair[0], pdir.pair[1], moveid);
// lfs_fs_prepmove(lfs, 0x3ff, NULL);
// }
//
// // replace bad pair, either we clean up desync, or no desync occured
// lpair[0] = pdir.pair[0];
// lpair[1] = pdir.pair[1];
// lfs_pair_tole32(ldir.pair);
// state = lfs_dir_relocatingcommit(lfs, &pdir, lpair, LFS_MKATTRS(
// {LFS_MKTAG_IF(moveid != 0x3ff,
// LFS_TYPE_DELETE, moveid, 0), NULL},
// {LFS_MKTAG(LFS_TYPE_TAIL + pdir.split, 0x3ff, 8),
// ldir.pair}),
// NULL);
// lfs_pair_fromle32(ldir.pair);
// if (state < 0) {
// return state;
// }
//
// ldir = pdir;
// }
// }
//
// return orphans ? LFS_OK_ORPHANED : 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
// const struct lfs_mattr *attrs, int attrcount) {
// int orphans = lfs_dir_orphaningcommit(lfs, dir, attrs, attrcount);
// if (orphans < 0) {
// return orphans;
// }
//
// if (orphans) {
// // make sure we've removed all orphans, this is a noop if there
// // are none, but if we had nested blocks failures we may have
// // created some
// int err = lfs_fs_deorphan(lfs, false);
// if (err) {
// return err;
// }
// }
//
// return 0;
//}
//#endif
//
//
///// Top level directory operations ///
//#ifndef LFS_READONLY
//static int lfs_rawmkdir(lfs_t *lfs, const char *path) {
// // deorphan if we haven't yet, needed at most once after poweron
// int err = lfs_fs_forceconsistency(lfs);
// if (err) {
// return err;
// }
//
// struct lfs_mlist cwd;
// cwd.next = lfs->mlist;
// uint16_t id;
// err = lfs_dir_find(lfs, &cwd.m, &path, &id);
// if (!(err == LFS_ERR_NOENT && id != 0x3ff)) {
// return (err < 0) ? err : LFS_ERR_EXIST;
// }
//
// // check that name fits
// lfs_size_t nlen = strlen(path);
// if (nlen > lfs->name_max) {
// return LFS_ERR_NAMETOOLONG;
// }
//
// // build up new directory
// lfs_alloc_ack(lfs);
// lfs_mdir_t dir;
// err = lfs_dir_alloc(lfs, &dir);
// if (err) {
// return err;
// }
//
// // find end of list
// lfs_mdir_t pred = cwd.m;
// while (pred.split) {
// err = lfs_dir_fetch(lfs, &pred, pred.tail);
// if (err) {
// return err;
// }
// }
//
// // setup dir
// lfs_pair_tole32(pred.tail);
// err = lfs_dir_commit(lfs, &dir, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8), pred.tail}));
// lfs_pair_fromle32(pred.tail);
// if (err) {
// return err;
// }
//
// // current block not end of list?
// if (cwd.m.split) {
// // update tails, this creates a desync
// err = lfs_fs_preporphans(lfs, +1);
// if (err) {
// return err;
// }
//
// // it's possible our predecessor has to be relocated, and if
// // our parent is our predecessor's predecessor, this could have
// // caused our parent to go out of date, fortunately we can hook
// // ourselves into littlefs to catch this
// cwd.type = 0;
// cwd.id = 0;
// lfs->mlist = &cwd;
//
// lfs_pair_tole32(dir.pair);
// err = lfs_dir_commit(lfs, &pred, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8), dir.pair}));
// lfs_pair_fromle32(dir.pair);
// if (err) {
// lfs->mlist = cwd.next;
// return err;
// }
//
// lfs->mlist = cwd.next;
// err = lfs_fs_preporphans(lfs, -1);
// if (err) {
// return err;
// }
// }
//
// // now insert into our parent block
// lfs_pair_tole32(dir.pair);
// err = lfs_dir_commit(lfs, &cwd.m, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_CREATE, id, 0), NULL},
// {LFS_MKTAG(LFS_TYPE_DIR, id, nlen), path},
// {LFS_MKTAG(LFS_TYPE_DIRSTRUCT, id, 8), dir.pair},
// {LFS_MKTAG_IF(!cwd.m.split,
// LFS_TYPE_SOFTTAIL, 0x3ff, 8), dir.pair}));
// lfs_pair_fromle32(dir.pair);
// if (err) {
// return err;
// }
//
// return 0;
//}
//#endif
//
//static int lfs_dir_rawopen(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
// lfs_stag_t tag = lfs_dir_find(lfs, &dir->m, &path, NULL);
// if (tag < 0) {
// return tag;
// }
//
// if (lfs_tag_type3(tag) != LFS_TYPE_DIR) {
// return LFS_ERR_NOTDIR;
// }
//
// lfs_block_t pair[2];
// if (lfs_tag_id(tag) == 0x3ff) {
// // handle root dir separately
// pair[0] = lfs->root[0];
// pair[1] = lfs->root[1];
// } else {
// // get dir pair from parent
// lfs_stag_t res = lfs_dir_get(lfs, &dir->m, LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tag_id(tag), 8), pair);
// if (res < 0) {
// return res;
// }
// lfs_pair_fromle32(pair);
// }
//
// // fetch first pair
// int err = lfs_dir_fetch(lfs, &dir->m, pair);
// if (err) {
// return err;
// }
//
// // setup entry
// dir->head[0] = dir->m.pair[0];
// dir->head[1] = dir->m.pair[1];
// dir->id = 0;
// dir->pos = 0;
//
// // add to list of mdirs
// dir->type = LFS_TYPE_DIR;
// lfs_mlist_append(lfs, (struct lfs_mlist *)dir);
//
// return 0;
//}
//
//static int lfs_dir_rawclose(lfs_t *lfs, lfs_dir_t *dir) {
// // remove from list of mdirs
// lfs_mlist_remove(lfs, (struct lfs_mlist *)dir);
//
// return 0;
//}
//
//static int lfs_dir_rawread(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info) {
// memset(info, 0, sizeof(*info));
//
// // special offset for '.' and '..'
// if (dir->pos == 0) {
// info->type = LFS_TYPE_DIR;
// strcpy(info->name, ".");
// dir->pos += 1;
// return true;
// } else if (dir->pos == 1) {
// info->type = LFS_TYPE_DIR;
// strcpy(info->name, "..");
// dir->pos += 1;
// return true;
// }
//
// while (true) {
// if (dir->id == dir->m.count) {
// if (!dir->m.split) {
// return false;
// }
//
// int err = lfs_dir_fetch(lfs, &dir->m, dir->m.tail);
// if (err) {
// return err;
// }
//
// dir->id = 0;
// }
//
// int err = lfs_dir_getinfo(lfs, &dir->m, dir->id, info);
// if (err && err != LFS_ERR_NOENT) {
// return err;
// }
//
// dir->id += 1;
// if (err != LFS_ERR_NOENT) {
// break;
// }
// }
//
// dir->pos += 1;
// return true;
//}
//
//static int lfs_dir_rawseek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off) {
// // simply walk from head dir
// int err = lfs_dir_rawrewind(lfs, dir);
// if (err) {
// return err;
// }
//
// // first two for ./..
// dir->pos = lfs_min(2, off);
// off -= dir->pos;
//
// // skip superblock entry
// dir->id = (off > 0 && lfs_pair_cmp(dir->head, lfs->root) == 0);
//
// while (off > 0) {
// int diff = lfs_min(dir->m.count - dir->id, off);
// dir->id += diff;
// dir->pos += diff;
// off -= diff;
//
// if (dir->id == dir->m.count) {
// if (!dir->m.split) {
// return LFS_ERR_INVAL;
// }
//
// err = lfs_dir_fetch(lfs, &dir->m, dir->m.tail);
// if (err) {
// return err;
// }
//
// dir->id = 0;
// }
// }
//
// return 0;
//}
//
//static lfs_soff_t lfs_dir_rawtell(lfs_t *lfs, lfs_dir_t *dir) {
// (void)lfs;
// return dir->pos;
//}
//
//static int lfs_dir_rawrewind(lfs_t *lfs, lfs_dir_t *dir) {
// // reload the head dir
// int err = lfs_dir_fetch(lfs, &dir->m, dir->head);
// if (err) {
// return err;
// }
//
// dir->id = 0;
// dir->pos = 0;
// return 0;
//}
//
//
///// File index list operations ///
//static int lfs_ctz_index(lfs_t *lfs, lfs_off_t *off) {
// lfs_off_t size = *off;
// lfs_off_t b = lfs->cfg->block_size - 2*4;
// lfs_off_t i = size / b;
// if (i == 0) {
// return 0;
// }
//
// i = (size - 4*(lfs_popc(i-1)+2)) / b;
// *off = size - b*i - 4*lfs_popc(i);
// return i;
//}
//
//static int lfs_ctz_find(lfs_t *lfs,
// const lfs_cache_t *pcache, lfs_cache_t *rcache,
// lfs_block_t head, lfs_size_t size,
// lfs_size_t pos, lfs_block_t *block, lfs_off_t *off) {
// if (size == 0) {
// *block = LFS_BLOCK_NULL;
// *off = 0;
// return 0;
// }
//
// lfs_off_t current = lfs_ctz_index(lfs, &(lfs_off_t){size-1});
// lfs_off_t target = lfs_ctz_index(lfs, &pos);
//
// while (current > target) {
// lfs_size_t skip = lfs_min(
// lfs_npw2(current-target+1) - 1,
// lfs_ctz(current));
//
// int err = lfs_bd_read(lfs,
// pcache, rcache, sizeof(head),
// head, 4*skip, &head, sizeof(head));
// head = lfs_fromle32(head);
// if (err) {
// return err;
// }
//
// current -= 1 << skip;
// }
//
// *block = head;
// *off = pos;
// return 0;
//}
//
//#ifndef LFS_READONLY
//static int lfs_ctz_extend(lfs_t *lfs,
// lfs_cache_t *pcache, lfs_cache_t *rcache,
// lfs_block_t head, lfs_size_t size,
// lfs_block_t *block, lfs_off_t *off) {
// while (true) {
// // go ahead and grab a block
// lfs_block_t nblock;
// int err = lfs_alloc(lfs, &nblock);
// if (err) {
// return err;
// }
//
// {
// err = lfs_bd_erase(lfs, nblock);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// if (size == 0) {
// *block = nblock;
// *off = 0;
// return 0;
// }
//
// lfs_size_t noff = size - 1;
// lfs_off_t index = lfs_ctz_index(lfs, &noff);
// noff = noff + 1;
//
// // just copy out the last block if it is incomplete
// if (noff != lfs->cfg->block_size) {
// for (lfs_off_t i = 0; i < noff; i++) {
// uint8_t data;
// err = lfs_bd_read(lfs,
// NULL, rcache, noff-i,
// head, i, &data, 1);
// if (err) {
// return err;
// }
//
// err = lfs_bd_prog(lfs,
// pcache, rcache, true,
// nblock, i, &data, 1);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
// }
//
// *block = nblock;
// *off = noff;
// return 0;
// }
//
// // append block
// index += 1;
// lfs_size_t skips = lfs_ctz(index) + 1;
// lfs_block_t nhead = head;
// for (lfs_off_t i = 0; i < skips; i++) {
// nhead = lfs_tole32(nhead);
// err = lfs_bd_prog(lfs, pcache, rcache, true,
// nblock, 4*i, &nhead, 4);
// nhead = lfs_fromle32(nhead);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// if (i != skips-1) {
// err = lfs_bd_read(lfs,
// NULL, rcache, sizeof(nhead),
// nhead, 4*i, &nhead, sizeof(nhead));
// nhead = lfs_fromle32(nhead);
// if (err) {
// return err;
// }
// }
// }
//
// *block = nblock;
// *off = 4*skips;
// return 0;
// }
//
//relocate:
// LFS_DEBUG("Bad block at 0x%"PRIx32, nblock);
//
// // just clear cache and try a new block
// lfs_cache_drop(lfs, pcache);
// }
//}
//#endif
//
//static int lfs_ctz_traverse(lfs_t *lfs,
// const lfs_cache_t *pcache, lfs_cache_t *rcache,
// lfs_block_t head, lfs_size_t size,
// int (*cb)(void*, lfs_block_t), void *data) {
// if (size == 0) {
// return 0;
// }
//
// lfs_off_t index = lfs_ctz_index(lfs, &(lfs_off_t){size-1});
//
// while (true) {
// int err = cb(data, head);
// if (err) {
// return err;
// }
//
// if (index == 0) {
// return 0;
// }
//
// lfs_block_t heads[2];
// int count = 2 - (index & 1);
// err = lfs_bd_read(lfs,
// pcache, rcache, count*sizeof(head),
// head, 0, &heads, count*sizeof(head));
// heads[0] = lfs_fromle32(heads[0]);
// heads[1] = lfs_fromle32(heads[1]);
// if (err) {
// return err;
// }
//
// for (int i = 0; i < count-1; i++) {
// err = cb(data, heads[i]);
// if (err) {
// return err;
// }
// }
//
// head = heads[count-1];
// index -= count;
// }
//}
//
//
///// Top level file operations ///
//static int lfs_file_rawopencfg(lfs_t *lfs, lfs_file_t *file,
// const char *path, int flags,
// const struct lfs_file_config *cfg) {
//#ifndef LFS_READONLY
// // deorphan if we haven't yet, needed at most once after poweron
// if ((flags & LFS_O_WRONLY) == LFS_O_WRONLY) {
// int err = lfs_fs_forceconsistency(lfs);
// if (err) {
// return err;
// }
// }
//#else
// LFS_ASSERT((flags & LFS_O_RDONLY) == LFS_O_RDONLY);
//#endif
//
// // setup simple file details
// int err;
// file->cfg = cfg;
// file->flags = flags;
// file->pos = 0;
// file->off = 0;
// file->cache.buffer = NULL;
//
// // allocate entry for file if it doesn't exist
// lfs_stag_t tag = lfs_dir_find(lfs, &file->m, &path, &file->id);
// if (tag < 0 && !(tag == LFS_ERR_NOENT && file->id != 0x3ff)) {
// err = tag;
// goto cleanup;
// }
//
// // get id, add to list of mdirs to catch update changes
// file->m.type = LFS_TYPE_REG;
// lfs_mlist_append(lfs, (struct lfs_mlist *)file);
//
//#ifdef LFS_READONLY
// if (tag == LFS_ERR_NOENT) {
// err = LFS_ERR_NOENT;
// goto cleanup;
//#else
// if (tag == LFS_ERR_NOENT) {
// if (!(flags & LFS_O_CREAT)) {
// err = LFS_ERR_NOENT;
// goto cleanup;
// }
//
// // check that name fits
// lfs_size_t nlen = strlen(path);
// if (nlen > lfs->name_max) {
// err = LFS_ERR_NAMETOOLONG;
// goto cleanup;
// }
//
// // get next slot and create entry to remember name
// err = lfs_dir_commit(lfs, &file->m, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_CREATE, file->id, 0), NULL},
// {LFS_MKTAG(LFS_TYPE_REG, file->id, nlen), path},
// {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0), NULL}));
//
// // it may happen that the file name doesn't fit in the metadata blocks, e.g., a 256 byte file name will
// // not fit in a 128 byte block.
// err = (err == LFS_ERR_NOSPC) ? LFS_ERR_NAMETOOLONG : err;
// if (err) {
// goto cleanup;
// }
//
// tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, 0);
// } else if (flags & LFS_O_EXCL) {
// err = LFS_ERR_EXIST;
// goto cleanup;
//#endif
// } else if (lfs_tag_type3(tag) != LFS_TYPE_REG) {
// err = LFS_ERR_ISDIR;
// goto cleanup;
//#ifndef LFS_READONLY
// } else if (flags & LFS_O_TRUNC) {
// // truncate if requested
// tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0);
// file->flags |= LFS_F_DIRTY;
//#endif
// } else {
// // try to load what's on disk, if it's inlined we'll fix it later
// tag = lfs_dir_get(lfs, &file->m, LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, file->id, 8), &file->ctz);
// if (tag < 0) {
// err = tag;
// goto cleanup;
// }
// lfs_ctz_fromle32(&file->ctz);
// }
//
// // fetch attrs
// for (unsigned i = 0; i < file->cfg->attr_count; i++) {
// // if opened for read / read-write operations
// if ((file->flags & LFS_O_RDONLY) == LFS_O_RDONLY) {
// lfs_stag_t res = lfs_dir_get(lfs, &file->m,
// LFS_MKTAG(0x7ff, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_USERATTR + file->cfg->attrs[i].type,
// file->id, file->cfg->attrs[i].size),
// file->cfg->attrs[i].buffer);
// if (res < 0 && res != LFS_ERR_NOENT) {
// err = res;
// goto cleanup;
// }
// }
//
//#ifndef LFS_READONLY
// // if opened for write / read-write operations
// if ((file->flags & LFS_O_WRONLY) == LFS_O_WRONLY) {
// if (file->cfg->attrs[i].size > lfs->attr_max) {
// err = LFS_ERR_NOSPC;
// goto cleanup;
// }
//
// file->flags |= LFS_F_DIRTY;
// }
//#endif
// }
//
// // allocate buffer if needed
// if (file->cfg->buffer) {
// file->cache.buffer = file->cfg->buffer;
// } else {
// file->cache.buffer = lfs_malloc(lfs->cfg->cache_size);
// if (!file->cache.buffer) {
// err = LFS_ERR_NOMEM;
// goto cleanup;
// }
// }
//
// // zero to avoid information leak
// lfs_cache_zero(lfs, &file->cache);
//
// if (lfs_tag_type3(tag) == LFS_TYPE_INLINESTRUCT) {
// // load inline files
// file->ctz.head = LFS_BLOCK_INLINE;
// file->ctz.size = lfs_tag_size(tag);
// file->flags |= LFS_F_INLINE;
// file->cache.block = file->ctz.head;
// file->cache.off = 0;
// file->cache.size = lfs->cfg->cache_size;
//
// // don't always read (may be new/trunc file)
// if (file->ctz.size > 0) {
// lfs_stag_t res = lfs_dir_get(lfs, &file->m,
// LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, file->id,
// lfs_min(file->cache.size, 0x3fe)),
// file->cache.buffer);
// if (res < 0) {
// err = res;
// goto cleanup;
// }
// }
// }
//
// return 0;
//
//cleanup:
// // clean up lingering resources
//#ifndef LFS_READONLY
// file->flags |= LFS_F_ERRED;
//#endif
// lfs_file_rawclose(lfs, file);
// return err;
//}
//
//#ifndef LFS_NO_MALLOC
//static int lfs_file_rawopen(lfs_t *lfs, lfs_file_t *file,
// const char *path, int flags) {
// static const struct lfs_file_config defaults = {0};
// int err = lfs_file_rawopencfg(lfs, file, path, flags, &defaults);
// return err;
//}
//#endif
//
//static int lfs_file_rawclose(lfs_t *lfs, lfs_file_t *file) {
//#ifndef LFS_READONLY
// int err = lfs_file_rawsync(lfs, file);
//#else
// int err = 0;
//#endif
//
// // remove from list of mdirs
// lfs_mlist_remove(lfs, (struct lfs_mlist*)file);
//
// // clean up memory
// if (!file->cfg->buffer) {
// lfs_free(file->cache.buffer);
// }
//
// return err;
//}
//
//
//#ifndef LFS_READONLY
//static int lfs_file_relocate(lfs_t *lfs, lfs_file_t *file) {
// while (true) {
// // just relocate what exists into new block
// lfs_block_t nblock;
// int err = lfs_alloc(lfs, &nblock);
// if (err) {
// return err;
// }
//
// err = lfs_bd_erase(lfs, nblock);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// // either read from dirty cache or disk
// for (lfs_off_t i = 0; i < file->off; i++) {
// uint8_t data;
// if (file->flags & LFS_F_INLINE) {
// err = lfs_dir_getread(lfs, &file->m,
// // note we evict inline files before they can be dirty
// NULL, &file->cache, file->off-i,
// LFS_MKTAG(0xfff, 0x1ff, 0),
// LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0),
// i, &data, 1);
// if (err) {
// return err;
// }
// } else {
// err = lfs_bd_read(lfs,
// &file->cache, &lfs->rcache, file->off-i,
// file->block, i, &data, 1);
// if (err) {
// return err;
// }
// }
//
// err = lfs_bd_prog(lfs,
// &lfs->pcache, &lfs->rcache, true,
// nblock, i, &data, 1);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
// }
//
// // copy over new state of file
// memcpy(file->cache.buffer, lfs->pcache.buffer, lfs->cfg->cache_size);
// file->cache.block = lfs->pcache.block;
// file->cache.off = lfs->pcache.off;
// file->cache.size = lfs->pcache.size;
// lfs_cache_zero(lfs, &lfs->pcache);
//
// file->block = nblock;
// file->flags |= LFS_F_WRITING;
// return 0;
//
//relocate:
// LFS_DEBUG("Bad block at 0x%"PRIx32, nblock);
//
// // just clear cache and try a new block
// lfs_cache_drop(lfs, &lfs->pcache);
// }
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_file_outline(lfs_t *lfs, lfs_file_t *file) {
// file->off = file->pos;
// lfs_alloc_ack(lfs);
// int err = lfs_file_relocate(lfs, file);
// if (err) {
// return err;
// }
//
// file->flags &= ~LFS_F_INLINE;
// return 0;
//}
//#endif
//
//static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
// if (file->flags & LFS_F_READING) {
// if (!(file->flags & LFS_F_INLINE)) {
// lfs_cache_drop(lfs, &file->cache);
// }
// file->flags &= ~LFS_F_READING;
// }
//
//#ifndef LFS_READONLY
// if (file->flags & LFS_F_WRITING) {
// lfs_off_t pos = file->pos;
//
// if (!(file->flags & LFS_F_INLINE)) {
// // copy over anything after current branch
// lfs_file_t orig = {
// .ctz.head = file->ctz.head,
// .ctz.size = file->ctz.size,
// .flags = LFS_O_RDONLY,
// .pos = file->pos,
// .cache = lfs->rcache,
// };
// lfs_cache_drop(lfs, &lfs->rcache);
//
// while (file->pos < file->ctz.size) {
// // copy over a byte at a time, leave it up to caching
// // to make this efficient
// uint8_t data;
// lfs_ssize_t res = lfs_file_flushedread(lfs, &orig, &data, 1);
// if (res < 0) {
// return res;
// }
//
// res = lfs_file_flushedwrite(lfs, file, &data, 1);
// if (res < 0) {
// return res;
// }
//
// // keep our reference to the rcache in sync
// if (lfs->rcache.block != LFS_BLOCK_NULL) {
// lfs_cache_drop(lfs, &orig.cache);
// lfs_cache_drop(lfs, &lfs->rcache);
// }
// }
//
// // write out what we have
// while (true) {
// int err = lfs_bd_flush(lfs, &file->cache, &lfs->rcache, true);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// return err;
// }
//
// break;
//
//relocate:
// LFS_DEBUG("Bad block at 0x%"PRIx32, file->block);
// err = lfs_file_relocate(lfs, file);
// if (err) {
// return err;
// }
// }
// } else {
// file->pos = lfs_max(file->pos, file->ctz.size);
// }
//
// // actual file updates
// file->ctz.head = file->block;
// file->ctz.size = file->pos;
// file->flags &= ~LFS_F_WRITING;
// file->flags |= LFS_F_DIRTY;
//
// file->pos = pos;
// }
//#endif
//
// return 0;
//}
//
//#ifndef LFS_READONLY
//static int lfs_file_rawsync(lfs_t *lfs, lfs_file_t *file) {
// if (file->flags & LFS_F_ERRED) {
// // it's not safe to do anything if our file errored
// return 0;
// }
//
// int err = lfs_file_flush(lfs, file);
// if (err) {
// file->flags |= LFS_F_ERRED;
// return err;
// }
//
//
// if ((file->flags & LFS_F_DIRTY) &&
// !lfs_pair_isnull(file->m.pair)) {
// // update dir entry
// uint16_t type;
// const void *buffer;
// lfs_size_t size;
// struct lfs_ctz ctz;
// if (file->flags & LFS_F_INLINE) {
// // inline the whole file
// type = LFS_TYPE_INLINESTRUCT;
// buffer = file->cache.buffer;
// size = file->ctz.size;
// } else {
// // update the ctz reference
// type = LFS_TYPE_CTZSTRUCT;
// // copy ctz so alloc will work during a relocate
// ctz = file->ctz;
// lfs_ctz_tole32(&ctz);
// buffer = &ctz;
// size = sizeof(ctz);
// }
//
// // commit file data and attributes
// err = lfs_dir_commit(lfs, &file->m, LFS_MKATTRS(
// {LFS_MKTAG(type, file->id, size), buffer},
// {LFS_MKTAG(LFS_FROM_USERATTRS, file->id,
// file->cfg->attr_count), file->cfg->attrs}));
// if (err) {
// file->flags |= LFS_F_ERRED;
// return err;
// }
//
// file->flags &= ~LFS_F_DIRTY;
// }
//
// return 0;
//}
//#endif
//
//static lfs_ssize_t lfs_file_flushedread(lfs_t *lfs, lfs_file_t *file,
// void *buffer, lfs_size_t size) {
// uint8_t *data = buffer;
// lfs_size_t nsize = size;
//
// if (file->pos >= file->ctz.size) {
// // eof if past end
// return 0;
// }
//
// size = lfs_min(size, file->ctz.size - file->pos);
// nsize = size;
//
// while (nsize > 0) {
// // check if we need a new block
// if (!(file->flags & LFS_F_READING) ||
// file->off == lfs->cfg->block_size) {
// if (!(file->flags & LFS_F_INLINE)) {
// int err = lfs_ctz_find(lfs, NULL, &file->cache,
// file->ctz.head, file->ctz.size,
// file->pos, &file->block, &file->off);
// if (err) {
// return err;
// }
// } else {
// file->block = LFS_BLOCK_INLINE;
// file->off = file->pos;
// }
//
// file->flags |= LFS_F_READING;
// }
//
// // read as much as we can in current block
// lfs_size_t diff = lfs_min(nsize, lfs->cfg->block_size - file->off);
// if (file->flags & LFS_F_INLINE) {
// int err = lfs_dir_getread(lfs, &file->m,
// NULL, &file->cache, lfs->cfg->block_size,
// LFS_MKTAG(0xfff, 0x1ff, 0),
// LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0),
// file->off, data, diff);
// if (err) {
// return err;
// }
// } else {
// int err = lfs_bd_read(lfs,
// NULL, &file->cache, lfs->cfg->block_size,
// file->block, file->off, data, diff);
// if (err) {
// return err;
// }
// }
//
// file->pos += diff;
// file->off += diff;
// data += diff;
// nsize -= diff;
// }
//
// return size;
//}
//
//static lfs_ssize_t lfs_file_rawread(lfs_t *lfs, lfs_file_t *file,
// void *buffer, lfs_size_t size) {
// LFS_ASSERT((file->flags & LFS_O_RDONLY) == LFS_O_RDONLY);
//
//#ifndef LFS_READONLY
// if (file->flags & LFS_F_WRITING) {
// // flush out any writes
// int err = lfs_file_flush(lfs, file);
// if (err) {
// return err;
// }
// }
//#endif
//
// return lfs_file_flushedread(lfs, file, buffer, size);
//}
//
//
//#ifndef LFS_READONLY
//static lfs_ssize_t lfs_file_flushedwrite(lfs_t *lfs, lfs_file_t *file,
// const void *buffer, lfs_size_t size) {
// const uint8_t *data = buffer;
// lfs_size_t nsize = size;
//
// if ((file->flags & LFS_F_INLINE) &&
// lfs_max(file->pos+nsize, file->ctz.size) >
// lfs_min(0x3fe, lfs_min(
// lfs->cfg->cache_size,
// (lfs->cfg->metadata_max ?
// lfs->cfg->metadata_max : lfs->cfg->block_size) / 8))) {
// // inline file doesn't fit anymore
// int err = lfs_file_outline(lfs, file);
// if (err) {
// file->flags |= LFS_F_ERRED;
// return err;
// }
// }
//
// while (nsize > 0) {
// // check if we need a new block
// if (!(file->flags & LFS_F_WRITING) ||
// file->off == lfs->cfg->block_size) {
// if (!(file->flags & LFS_F_INLINE)) {
// if (!(file->flags & LFS_F_WRITING) && file->pos > 0) {
// // find out which block we're extending from
// int err = lfs_ctz_find(lfs, NULL, &file->cache,
// file->ctz.head, file->ctz.size,
// file->pos-1, &file->block, &file->off);
// if (err) {
// file->flags |= LFS_F_ERRED;
// return err;
// }
//
// // mark cache as dirty since we may have read data into it
// lfs_cache_zero(lfs, &file->cache);
// }
//
// // extend file with new blocks
// lfs_alloc_ack(lfs);
// int err = lfs_ctz_extend(lfs, &file->cache, &lfs->rcache,
// file->block, file->pos,
// &file->block, &file->off);
// if (err) {
// file->flags |= LFS_F_ERRED;
// return err;
// }
// } else {
// file->block = LFS_BLOCK_INLINE;
// file->off = file->pos;
// }
//
// file->flags |= LFS_F_WRITING;
// }
//
// // program as much as we can in current block
// lfs_size_t diff = lfs_min(nsize, lfs->cfg->block_size - file->off);
// while (true) {
// int err = lfs_bd_prog(lfs, &file->cache, &lfs->rcache, true,
// file->block, file->off, data, diff);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// goto relocate;
// }
// file->flags |= LFS_F_ERRED;
// return err;
// }
//
// break;
//relocate:
// err = lfs_file_relocate(lfs, file);
// if (err) {
// file->flags |= LFS_F_ERRED;
// return err;
// }
// }
//
// file->pos += diff;
// file->off += diff;
// data += diff;
// nsize -= diff;
//
// lfs_alloc_ack(lfs);
// }
//
// return size;
//}
//
//static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
// const void *buffer, lfs_size_t size) {
// LFS_ASSERT((file->flags & LFS_O_WRONLY) == LFS_O_WRONLY);
//
// if (file->flags & LFS_F_READING) {
// // drop any reads
// int err = lfs_file_flush(lfs, file);
// if (err) {
// return err;
// }
// }
//
// if ((file->flags & LFS_O_APPEND) && file->pos < file->ctz.size) {
// file->pos = file->ctz.size;
// }
//
// if (file->pos + size > lfs->file_max) {
// // Larger than file limit?
// return LFS_ERR_FBIG;
// }
//
// if (!(file->flags & LFS_F_WRITING) && file->pos > file->ctz.size) {
// // fill with zeros
// lfs_off_t pos = file->pos;
// file->pos = file->ctz.size;
//
// while (file->pos < pos) {
// lfs_ssize_t res = lfs_file_flushedwrite(lfs, file, &(uint8_t){0}, 1);
// if (res < 0) {
// return res;
// }
// }
// }
//
// lfs_ssize_t nsize = lfs_file_flushedwrite(lfs, file, buffer, size);
// if (nsize < 0) {
// return nsize;
// }
//
// file->flags &= ~LFS_F_ERRED;
// return nsize;
//}
//#endif
//
//static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
// lfs_soff_t off, int whence) {
// // find new pos
// lfs_off_t npos = file->pos;
// if (whence == LFS_SEEK_SET) {
// npos = off;
// } else if (whence == LFS_SEEK_CUR) {
// if ((lfs_soff_t)file->pos + off < 0) {
// return LFS_ERR_INVAL;
// } else {
// npos = file->pos + off;
// }
// } else if (whence == LFS_SEEK_END) {
// lfs_soff_t res = lfs_file_rawsize(lfs, file) + off;
// if (res < 0) {
// return LFS_ERR_INVAL;
// } else {
// npos = res;
// }
// }
//
// if (npos > lfs->file_max) {
// // file position out of range
// return LFS_ERR_INVAL;
// }
//
// if (file->pos == npos) {
// // noop - position has not changed
// return npos;
// }
//
// // if we're only reading and our new offset is still in the file's cache
// // we can avoid flushing and needing to reread the data
// if (
//#ifndef LFS_READONLY
// !(file->flags & LFS_F_WRITING)
//#else
// true
//#endif
// ) {
// int oindex = lfs_ctz_index(lfs, &(lfs_off_t){file->pos});
// lfs_off_t noff = npos;
// int nindex = lfs_ctz_index(lfs, &noff);
// if (oindex == nindex
// && noff >= file->cache.off
// && noff < file->cache.off + file->cache.size) {
// file->pos = npos;
// file->off = noff;
// return npos;
// }
// }
//
// // write out everything beforehand, may be noop if rdonly
// int err = lfs_file_flush(lfs, file);
// if (err) {
// return err;
// }
//
// // update pos
// file->pos = npos;
// return npos;
//}
//
//#ifndef LFS_READONLY
//static int lfs_file_rawtruncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
// LFS_ASSERT((file->flags & LFS_O_WRONLY) == LFS_O_WRONLY);
//
// if (size > LFS_FILE_MAX) {
// return LFS_ERR_INVAL;
// }
//
// lfs_off_t pos = file->pos;
// lfs_off_t oldsize = lfs_file_rawsize(lfs, file);
// if (size < oldsize) {
// // need to flush since directly changing metadata
// int err = lfs_file_flush(lfs, file);
// if (err) {
// return err;
// }
//
// // lookup new head in ctz skip list
// err = lfs_ctz_find(lfs, NULL, &file->cache,
// file->ctz.head, file->ctz.size,
// size, &file->block, &file->off);
// if (err) {
// return err;
// }
//
// // need to set pos/block/off consistently so seeking back to
// // the old position does not get confused
// file->pos = size;
// file->ctz.head = file->block;
// file->ctz.size = size;
// file->flags |= LFS_F_DIRTY | LFS_F_READING;
// } else if (size > oldsize) {
// // flush+seek if not already at end
// lfs_soff_t res = lfs_file_rawseek(lfs, file, 0, LFS_SEEK_END);
// if (res < 0) {
// return (int)res;
// }
//
// // fill with zeros
// while (file->pos < size) {
// res = lfs_file_rawwrite(lfs, file, &(uint8_t){0}, 1);
// if (res < 0) {
// return (int)res;
// }
// }
// }
//
// // restore pos
// lfs_soff_t res = lfs_file_rawseek(lfs, file, pos, LFS_SEEK_SET);
// if (res < 0) {
// return (int)res;
// }
//
// return 0;
//}
//#endif
//
//static lfs_soff_t lfs_file_rawtell(lfs_t *lfs, lfs_file_t *file) {
// (void)lfs;
// return file->pos;
//}
//
//static int lfs_file_rawrewind(lfs_t *lfs, lfs_file_t *file) {
// lfs_soff_t res = lfs_file_rawseek(lfs, file, 0, LFS_SEEK_SET);
// if (res < 0) {
// return (int)res;
// }
//
// return 0;
//}
//
//static lfs_soff_t lfs_file_rawsize(lfs_t *lfs, lfs_file_t *file) {
// (void)lfs;
//
//#ifndef LFS_READONLY
// if (file->flags & LFS_F_WRITING) {
// return lfs_max(file->pos, file->ctz.size);
// }
//#endif
//
// return file->ctz.size;
//}
//
//
///// General fs operations ///
//static int lfs_rawstat(lfs_t *lfs, const char *path, struct lfs_info *info) {
// lfs_mdir_t cwd;
// lfs_stag_t tag = lfs_dir_find(lfs, &cwd, &path, NULL);
// if (tag < 0) {
// return (int)tag;
// }
//
// return lfs_dir_getinfo(lfs, &cwd, lfs_tag_id(tag), info);
//}
//
//#ifndef LFS_READONLY
//static int lfs_rawremove(lfs_t *lfs, const char *path) {
// // deorphan if we haven't yet, needed at most once after poweron
// int err = lfs_fs_forceconsistency(lfs);
// if (err) {
// return err;
// }
//
// lfs_mdir_t cwd;
// lfs_stag_t tag = lfs_dir_find(lfs, &cwd, &path, NULL);
// if (tag < 0 || lfs_tag_id(tag) == 0x3ff) {
// return (tag < 0) ? (int)tag : LFS_ERR_INVAL;
// }
//
// struct lfs_mlist dir;
// dir.next = lfs->mlist;
// if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
// // must be empty before removal
// lfs_block_t pair[2];
// lfs_stag_t res = lfs_dir_get(lfs, &cwd, LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tag_id(tag), 8), pair);
// if (res < 0) {
// return (int)res;
// }
// lfs_pair_fromle32(pair);
//
// err = lfs_dir_fetch(lfs, &dir.m, pair);
// if (err) {
// return err;
// }
//
// if (dir.m.count > 0 || dir.m.split) {
// return LFS_ERR_NOTEMPTY;
// }
//
// // mark fs as orphaned
// err = lfs_fs_preporphans(lfs, +1);
// if (err) {
// return err;
// }
//
// // I know it's crazy but yes, dir can be changed by our parent's
// // commit (if predecessor is child)
// dir.type = 0;
// dir.id = 0;
// lfs->mlist = &dir;
// }
//
// // delete the entry
// err = lfs_dir_commit(lfs, &cwd, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(tag), 0), NULL}));
// if (err) {
// lfs->mlist = dir.next;
// return err;
// }
//
// lfs->mlist = dir.next;
// if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
// // fix orphan
// err = lfs_fs_preporphans(lfs, -1);
// if (err) {
// return err;
// }
//
// err = lfs_fs_pred(lfs, dir.m.pair, &cwd);
// if (err) {
// return err;
// }
//
// err = lfs_dir_drop(lfs, &cwd, &dir.m);
// if (err) {
// return err;
// }
// }
//
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_rawrename(lfs_t *lfs, const char *oldpath, const char *newpath) {
// // deorphan if we haven't yet, needed at most once after poweron
// int err = lfs_fs_forceconsistency(lfs);
// if (err) {
// return err;
// }
//
// // find old entry
// lfs_mdir_t oldcwd;
// lfs_stag_t oldtag = lfs_dir_find(lfs, &oldcwd, &oldpath, NULL);
// if (oldtag < 0 || lfs_tag_id(oldtag) == 0x3ff) {
// return (oldtag < 0) ? (int)oldtag : LFS_ERR_INVAL;
// }
//
// // find new entry
// lfs_mdir_t newcwd;
// uint16_t newid;
// lfs_stag_t prevtag = lfs_dir_find(lfs, &newcwd, &newpath, &newid);
// if ((prevtag < 0 || lfs_tag_id(prevtag) == 0x3ff) &&
// !(prevtag == LFS_ERR_NOENT && newid != 0x3ff)) {
// return (prevtag < 0) ? (int)prevtag : LFS_ERR_INVAL;
// }
//
// // if we're in the same pair there's a few special cases...
// bool samepair = (lfs_pair_cmp(oldcwd.pair, newcwd.pair) == 0);
// uint16_t newoldid = lfs_tag_id(oldtag);
//
// struct lfs_mlist prevdir;
// prevdir.next = lfs->mlist;
// if (prevtag == LFS_ERR_NOENT) {
// // check that name fits
// lfs_size_t nlen = strlen(newpath);
// if (nlen > lfs->name_max) {
// return LFS_ERR_NAMETOOLONG;
// }
//
// // there is a small chance we are being renamed in the same
// // directory/ to an id less than our old id, the global update
// // to handle this is a bit messy
// if (samepair && newid <= newoldid) {
// newoldid += 1;
// }
// } else if (lfs_tag_type3(prevtag) != lfs_tag_type3(oldtag)) {
// return LFS_ERR_ISDIR;
// } else if (samepair && newid == newoldid) {
// // we're renaming to ourselves??
// return 0;
// } else if (lfs_tag_type3(prevtag) == LFS_TYPE_DIR) {
// // must be empty before removal
// lfs_block_t prevpair[2];
// lfs_stag_t res = lfs_dir_get(lfs, &newcwd, LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, newid, 8), prevpair);
// if (res < 0) {
// return (int)res;
// }
// lfs_pair_fromle32(prevpair);
//
// // must be empty before removal
// err = lfs_dir_fetch(lfs, &prevdir.m, prevpair);
// if (err) {
// return err;
// }
//
// if (prevdir.m.count > 0 || prevdir.m.split) {
// return LFS_ERR_NOTEMPTY;
// }
//
// // mark fs as orphaned
// err = lfs_fs_preporphans(lfs, +1);
// if (err) {
// return err;
// }
//
// // I know it's crazy but yes, dir can be changed by our parent's
// // commit (if predecessor is child)
// prevdir.type = 0;
// prevdir.id = 0;
// lfs->mlist = &prevdir;
// }
//
// if (!samepair) {
// lfs_fs_prepmove(lfs, newoldid, oldcwd.pair);
// }
//
// // move over all attributes
// err = lfs_dir_commit(lfs, &newcwd, LFS_MKATTRS(
// {LFS_MKTAG_IF(prevtag != LFS_ERR_NOENT,
// LFS_TYPE_DELETE, newid, 0), NULL},
// {LFS_MKTAG(LFS_TYPE_CREATE, newid, 0), NULL},
// {LFS_MKTAG(lfs_tag_type3(oldtag), newid, strlen(newpath)), newpath},
// {LFS_MKTAG(LFS_FROM_MOVE, newid, lfs_tag_id(oldtag)), &oldcwd},
// {LFS_MKTAG_IF(samepair,
// LFS_TYPE_DELETE, newoldid, 0), NULL}));
// if (err) {
// lfs->mlist = prevdir.next;
// return err;
// }
//
// // let commit clean up after move (if we're different! otherwise move
// // logic already fixed it for us)
// if (!samepair && lfs_gstate_hasmove(&lfs->gstate)) {
// // prep gstate and delete move id
// lfs_fs_prepmove(lfs, 0x3ff, NULL);
// err = lfs_dir_commit(lfs, &oldcwd, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(oldtag), 0), NULL}));
// if (err) {
// lfs->mlist = prevdir.next;
// return err;
// }
// }
//
// lfs->mlist = prevdir.next;
// if (prevtag != LFS_ERR_NOENT
// && lfs_tag_type3(prevtag) == LFS_TYPE_DIR) {
// // fix orphan
// err = lfs_fs_preporphans(lfs, -1);
// if (err) {
// return err;
// }
//
// err = lfs_fs_pred(lfs, prevdir.m.pair, &newcwd);
// if (err) {
// return err;
// }
//
// err = lfs_dir_drop(lfs, &newcwd, &prevdir.m);
// if (err) {
// return err;
// }
// }
//
// return 0;
//}
//#endif
//
//static lfs_ssize_t lfs_rawgetattr(lfs_t *lfs, const char *path,
// uint8_t type, void *buffer, lfs_size_t size) {
// lfs_mdir_t cwd;
// lfs_stag_t tag = lfs_dir_find(lfs, &cwd, &path, NULL);
// if (tag < 0) {
// return tag;
// }
//
// uint16_t id = lfs_tag_id(tag);
// if (id == 0x3ff) {
// // special case for root
// id = 0;
// int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
// if (err) {
// return err;
// }
// }
//
// tag = lfs_dir_get(lfs, &cwd, LFS_MKTAG(0x7ff, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_USERATTR + type,
// id, lfs_min(size, lfs->attr_max)),
// buffer);
// if (tag < 0) {
// if (tag == LFS_ERR_NOENT) {
// return LFS_ERR_NOATTR;
// }
//
// return tag;
// }
//
// return lfs_tag_size(tag);
//}
//
//#ifndef LFS_READONLY
//static int lfs_commitattr(lfs_t *lfs, const char *path,
// uint8_t type, const void *buffer, lfs_size_t size) {
// lfs_mdir_t cwd;
// lfs_stag_t tag = lfs_dir_find(lfs, &cwd, &path, NULL);
// if (tag < 0) {
// return tag;
// }
//
// uint16_t id = lfs_tag_id(tag);
// if (id == 0x3ff) {
// // special case for root
// id = 0;
// int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
// if (err) {
// return err;
// }
// }
//
// return lfs_dir_commit(lfs, &cwd, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_USERATTR + type, id, size), buffer}));
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_rawsetattr(lfs_t *lfs, const char *path,
// uint8_t type, const void *buffer, lfs_size_t size) {
// if (size > lfs->attr_max) {
// return LFS_ERR_NOSPC;
// }
//
// return lfs_commitattr(lfs, path, type, buffer, size);
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_rawremoveattr(lfs_t *lfs, const char *path, uint8_t type) {
// return lfs_commitattr(lfs, path, type, NULL, 0x3ff);
//}
//#endif
//
/// Filesystem operations ///
static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
lfs->cfg = cfg;
int err = 0;
// validate that the lfs-cfg sizes were initiated properly before
// performing any arithmetic logics with them
LFS_ASSERT(lfs->cfg->read_size != 0);
LFS_ASSERT(lfs->cfg->prog_size != 0);
LFS_ASSERT(lfs->cfg->cache_size != 0);
// check that block size is a multiple of cache size is a multiple
// of prog and read sizes
LFS_ASSERT(lfs->cfg->cache_size % lfs->cfg->read_size == 0);
LFS_ASSERT(lfs->cfg->cache_size % lfs->cfg->prog_size == 0);
LFS_ASSERT(lfs->cfg->block_size % lfs->cfg->cache_size == 0);
// check that the block size is large enough to fit ctz pointers
LFS_ASSERT(4*lfs_npw2(0xffffffff / (lfs->cfg->block_size-2*4))
<= lfs->cfg->block_size);
// block_cycles = 0 is no longer supported.
//
// block_cycles is the number of erase cycles before littlefs evicts
// metadata logs as a part of wear leveling. Suggested values are in the
// range of 100-1000, or set block_cycles to -1 to disable block-level
// wear-leveling.
LFS_ASSERT(lfs->cfg->block_cycles != 0);
// setup read cache
if (lfs->cfg->read_buffer) {
lfs->rcache.buffer = lfs->cfg->read_buffer;
} else {
lfs->rcache.buffer = lfs_malloc(lfs->cfg->cache_size);
if (!lfs->rcache.buffer) {
err = LFS_ERR_NOMEM;
goto failed;
}
}
// setup program cache
if (lfs->cfg->prog_buffer) {
lfs->pcache.buffer = lfs->cfg->prog_buffer;
} else {
lfs->pcache.buffer = lfs_malloc(lfs->cfg->cache_size);
if (!lfs->pcache.buffer) {
err = LFS_ERR_NOMEM;
goto failed;
}
}
// zero to avoid information leaks
lfs_cache_zero(lfs, &lfs->rcache);
lfs_cache_zero(lfs, &lfs->pcache);
// setup lookahead buffer, note mount finishes initializing this after
// we establish a decent pseudo-random seed
LFS_ASSERT(lfs->cfg->lookahead_size > 0);
if (lfs->cfg->lookahead_buffer) {
lfs->lookahead.buffer = lfs->cfg->lookahead_buffer;
} else {
lfs->lookahead.buffer = lfs_malloc(lfs->cfg->lookahead_size);
if (!lfs->lookahead.buffer) {
err = LFS_ERR_NOMEM;
goto failed;
}
}
lfs->lookahead.start = 0;
lfs->lookahead.size = 0;
lfs->lookahead.next = 0;
lfs->lookahead.ckpoint = 0;
// check that the size limits are sane
LFS_ASSERT(lfs->cfg->name_limit <= LFS_NAME_MAX);
lfs->name_limit = lfs->cfg->name_limit;
if (!lfs->name_limit) {
lfs->name_limit = LFS_NAME_MAX;
}
LFS_ASSERT(lfs->cfg->size_limit <= LFS_FILE_MAX);
lfs->size_limit = lfs->cfg->size_limit;
if (!lfs->size_limit) {
lfs->size_limit = LFS_FILE_MAX;
}
LFS_ASSERT(lfs->cfg->uattr_limit <= LFS_UATTR_MAX);
lfs->uattr_limit = lfs->cfg->uattr_limit;
if (!lfs->uattr_limit) {
lfs->uattr_limit = LFS_UATTR_MAX;
}
LFS_ASSERT(lfs->cfg->sattr_limit <= LFS_SATTR_MAX);
lfs->sattr_limit = lfs->cfg->sattr_limit;
if (!lfs->sattr_limit) {
lfs->sattr_limit = LFS_SATTR_MAX;
}
// setup default state
lfs->root[0] = LFS_BLOCK_NULL;
lfs->root[1] = LFS_BLOCK_NULL;
lfs->mlist = NULL;
lfs->seed = 0;
lfs->gdisk = (lfs_gstate_t){0};
lfs->gstate = (lfs_gstate_t){0};
lfs->gdelta = (lfs_gstate_t){0};
#ifdef LFS_MIGRATE
lfs->lfs1 = NULL;
#endif
// TODO maybe reorganize this function?
lfs->hasorphans = false;
// compute the number of bits we need to reserve for metadata rids
//
// This is equivalent to the nlog2 of the maximum number of rids we can
// ever have in a single mdir. With some knowledge of our system we can
// find a conservative, but useful, limit to this upper bound:
//
// - Each tag needs <=2 alts+null with our current compaction strategy
// - Each tag/alt encodes to a minimum of 4 bytes
//
// This gives us ~4*4 or ~16 bytes per mid at minimum. If we cram an mdir
// with the smallest possible mids, this gives us at most ~block_size/16
// mids in a single mdir before the mdir runs out of space.
//
// Note we can't assume ~1/2 block utilization here, as an mdir may
// temporarily fill with more mids before compaction occurs.
//
lfs->mbits = lfs_nlog2(lfs->cfg->block_size/16);
// zero linked-list of opened mdirs
lfs->opened = NULL;
// zero gstate
memset(lfs->grm_g, 0, LFSR_GRM_DSIZE);
memset(lfs->grm_d, 0, LFSR_GRM_DSIZE);
return 0;
failed:;
lfs_deinit(lfs);
return err;
}
static int lfs_deinit(lfs_t *lfs) {
// free allocated memory
if (!lfs->cfg->read_buffer) {
lfs_free(lfs->rcache.buffer);
}
if (!lfs->cfg->prog_buffer) {
lfs_free(lfs->pcache.buffer);
}
if (!lfs->cfg->lookahead_buffer) {
lfs_free(lfs->lookahead.buffer);
}
return 0;
}
//#ifndef LFS_READONLY
//static int lfs_rawformat(lfs_t *lfs, const struct lfs_config *cfg) {
// int err = 0;
// {
// err = lfs_init(lfs, cfg);
// if (err) {
// return err;
// }
//
// // create free lookahead
// memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);
// lfs->free.off = 0;
// lfs->free.size = lfs_min(8*lfs->cfg->lookahead_size,
// lfs->cfg->block_count);
// lfs->free.i = 0;
// lfs_alloc_ack(lfs);
//
// // create root dir
// lfs_mdir_t root;
// err = lfs_dir_alloc(lfs, &root);
// if (err) {
// goto cleanup;
// }
//
// // write one superblock
// lfs_superblock_t superblock = {
// .version = LFS_DISK_VERSION,
// .block_size = lfs->cfg->block_size,
// .block_count = lfs->cfg->block_count,
// .name_max = lfs->name_max,
// .file_max = lfs->file_max,
// .attr_max = lfs->attr_max,
// };
//
// lfs_superblock_tole32(&superblock);
// err = lfs_dir_commit(lfs, &root, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_CREATE, 0, 0), NULL},
// {LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
// {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
// &superblock}));
// if (err) {
// goto cleanup;
// }
//
// // force compaction to prevent accidentally mounting any
// // older version of littlefs that may live on disk
// root.erased = false;
// err = lfs_dir_commit(lfs, &root, NULL, 0);
// if (err) {
// goto cleanup;
// }
//
// // sanity check that fetch works
// err = lfs_dir_fetch(lfs, &root, (const lfs_block_t[2]){0, 1});
// if (err) {
// goto cleanup;
// }
// }
//
//cleanup:
// lfs_deinit(lfs);
// return err;
//
//}
//#endif
//
//static int lfs_rawmount(lfs_t *lfs, const struct lfs_config *cfg) {
// int err = lfs_init(lfs, cfg);
// if (err) {
// return err;
// }
//
// // scan directory blocks for superblock and any global updates
// lfs_mdir_t dir = {.tail = {0, 1}};
// lfs_block_t tortoise[2] = {LFS_BLOCK_NULL, LFS_BLOCK_NULL};
// lfs_size_t tortoise_i = 1;
// lfs_size_t tortoise_period = 1;
// while (!lfs_pair_isnull(dir.tail)) {
// // detect cycles with Brent's algorithm
// if (lfs_pair_issync(dir.tail, tortoise)) {
// LFS_ERROR("Cycle detected in tail list");
// err = LFS_ERR_CORRUPT;
// goto cleanup;
// }
// if (tortoise_i == tortoise_period) {
// tortoise[0] = dir.tail[0];
// tortoise[1] = dir.tail[1];
// tortoise_i = 0;
// tortoise_period *= 2;
// }
// tortoise_i += 1;
//
// // fetch next block in tail list
// lfs_stag_t tag = lfs_dir_fetchmatch(lfs, &dir, dir.tail,
// LFS_MKTAG(0x7ff, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8),
// NULL,
// lfs_dir_find_match, &(struct lfs_dir_find_match){
// lfs, "littlefs", 8});
// if (tag < 0) {
// err = tag;
// goto cleanup;
// }
//
// // has superblock?
// if (tag && !lfs_tag_isdelete(tag)) {
// // update root
// lfs->root[0] = dir.pair[0];
// lfs->root[1] = dir.pair[1];
//
// // grab superblock
// lfs_superblock_t superblock;
// tag = lfs_dir_get(lfs, &dir, LFS_MKTAG(0x7ff, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
// &superblock);
// if (tag < 0) {
// err = tag;
// goto cleanup;
// }
// lfs_superblock_fromle32(&superblock);
//
// // check version
// uint16_t major_version = (0xffff & (superblock.version >> 16));
// uint16_t minor_version = (0xffff & (superblock.version >> 0));
// if ((major_version != LFS_DISK_VERSION_MAJOR ||
// minor_version > LFS_DISK_VERSION_MINOR)) {
// LFS_ERROR("Invalid version v%"PRIu16".%"PRIu16,
// major_version, minor_version);
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
//
// // check superblock configuration
// if (superblock.name_max) {
// if (superblock.name_max > lfs->name_max) {
// LFS_ERROR("Unsupported name_max (%"PRIu32" > %"PRIu32")",
// superblock.name_max, lfs->name_max);
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
//
// lfs->name_max = superblock.name_max;
// }
//
// if (superblock.file_max) {
// if (superblock.file_max > lfs->file_max) {
// LFS_ERROR("Unsupported file_max (%"PRIu32" > %"PRIu32")",
// superblock.file_max, lfs->file_max);
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
//
// lfs->file_max = superblock.file_max;
// }
//
// if (superblock.attr_max) {
// if (superblock.attr_max > lfs->attr_max) {
// LFS_ERROR("Unsupported attr_max (%"PRIu32" > %"PRIu32")",
// superblock.attr_max, lfs->attr_max);
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
//
// lfs->attr_max = superblock.attr_max;
// }
//
// if (superblock.block_count != lfs->cfg->block_count) {
// LFS_ERROR("Invalid block count (%"PRIu32" != %"PRIu32")",
// superblock.block_count, lfs->cfg->block_count);
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
//
// if (superblock.block_size != lfs->cfg->block_size) {
// LFS_ERROR("Invalid block size (%"PRIu32" != %"PRIu32")",
// superblock.block_size, lfs->cfg->block_size);
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
// }
//
// // has gstate?
// err = lfs_dir_getgstate(lfs, &dir, &lfs->gstate);
// if (err) {
// goto cleanup;
// }
// }
//
// // found superblock?
// if (lfs_pair_isnull(lfs->root)) {
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
//
// // update littlefs with gstate
// if (!lfs_gstate_iszero(&lfs->gstate)) {
// LFS_DEBUG("Found pending gstate 0x%08"PRIx32"%08"PRIx32"%08"PRIx32,
// lfs->gstate.tag,
// lfs->gstate.pair[0],
// lfs->gstate.pair[1]);
// }
// lfs->gstate.tag += !lfs_tag_isvalid(lfs->gstate.tag);
// lfs->gdisk = lfs->gstate;
//
// // setup free lookahead, to distribute allocations uniformly across
// // boots, we start the allocator at a random location
// lfs->free.off = lfs->seed % lfs->cfg->block_count;
// lfs_alloc_drop(lfs);
//
// return 0;
//
//cleanup:
// lfs_rawunmount(lfs);
// return err;
//}
//
//static int lfs_rawunmount(lfs_t *lfs) {
// return lfs_deinit(lfs);
//}
//
//
///// Filesystem filesystem operations ///
//int lfs_fs_rawtraverse(lfs_t *lfs,
// int (*cb)(void *data, lfs_block_t block), void *data,
// bool includeorphans) {
// // iterate over metadata pairs
// lfs_mdir_t dir = {.tail = {0, 1}};
//
//#ifdef LFS_MIGRATE
// // also consider v1 blocks during migration
// if (lfs->lfs1) {
// int err = lfs1_traverse(lfs, cb, data);
// if (err) {
// return err;
// }
//
// dir.tail[0] = lfs->root[0];
// dir.tail[1] = lfs->root[1];
// }
//#endif
//
// lfs_block_t tortoise[2] = {LFS_BLOCK_NULL, LFS_BLOCK_NULL};
// lfs_size_t tortoise_i = 1;
// lfs_size_t tortoise_period = 1;
// while (!lfs_pair_isnull(dir.tail)) {
// // detect cycles with Brent's algorithm
// if (lfs_pair_issync(dir.tail, tortoise)) {
// LFS_WARN("Cycle detected in tail list");
// return LFS_ERR_CORRUPT;
// }
// if (tortoise_i == tortoise_period) {
// tortoise[0] = dir.tail[0];
// tortoise[1] = dir.tail[1];
// tortoise_i = 0;
// tortoise_period *= 2;
// }
// tortoise_i += 1;
//
// for (int i = 0; i < 2; i++) {
// int err = cb(data, dir.tail[i]);
// if (err) {
// return err;
// }
// }
//
// // iterate through ids in directory
// int err = lfs_dir_fetch(lfs, &dir, dir.tail);
// if (err) {
// return err;
// }
//
// for (uint16_t id = 0; id < dir.count; id++) {
// struct lfs_ctz ctz;
// lfs_stag_t tag = lfs_dir_get(lfs, &dir, LFS_MKTAG(0x700, 0x3ff, 0),
// LFS_MKTAG(LFS_TYPE_STRUCT, id, sizeof(ctz)), &ctz);
// if (tag < 0) {
// if (tag == LFS_ERR_NOENT) {
// continue;
// }
// return tag;
// }
// lfs_ctz_fromle32(&ctz);
//
// if (lfs_tag_type3(tag) == LFS_TYPE_CTZSTRUCT) {
// err = lfs_ctz_traverse(lfs, NULL, &lfs->rcache,
// ctz.head, ctz.size, cb, data);
// if (err) {
// return err;
// }
// } else if (includeorphans &&
// lfs_tag_type3(tag) == LFS_TYPE_DIRSTRUCT) {
// for (int i = 0; i < 2; i++) {
// err = cb(data, (&ctz.head)[i]);
// if (err) {
// return err;
// }
// }
// }
// }
// }
//
//#ifndef LFS_READONLY
// // iterate over any open files
// for (lfs_file_t *f = (lfs_file_t*)lfs->mlist; f; f = f->next) {
// if (f->type != LFS_TYPE_REG) {
// continue;
// }
//
// if ((f->flags & LFS_F_DIRTY) && !(f->flags & LFS_F_INLINE)) {
// int err = lfs_ctz_traverse(lfs, &f->cache, &lfs->rcache,
// f->ctz.head, f->ctz.size, cb, data);
// if (err) {
// return err;
// }
// }
//
// if ((f->flags & LFS_F_WRITING) && !(f->flags & LFS_F_INLINE)) {
// int err = lfs_ctz_traverse(lfs, &f->cache, &lfs->rcache,
// f->block, f->pos, cb, data);
// if (err) {
// return err;
// }
// }
// }
//#endif
//
// return 0;
//}
//
//#ifndef LFS_READONLY
//static int lfs_fs_pred(lfs_t *lfs,
// const lfs_block_t pair[2], lfs_mdir_t *pdir) {
// // iterate over all directory directory entries
// pdir->tail[0] = 0;
// pdir->tail[1] = 1;
// lfs_block_t tortoise[2] = {LFS_BLOCK_NULL, LFS_BLOCK_NULL};
// lfs_size_t tortoise_i = 1;
// lfs_size_t tortoise_period = 1;
// while (!lfs_pair_isnull(pdir->tail)) {
// // detect cycles with Brent's algorithm
// if (lfs_pair_issync(pdir->tail, tortoise)) {
// LFS_WARN("Cycle detected in tail list");
// return LFS_ERR_CORRUPT;
// }
// if (tortoise_i == tortoise_period) {
// tortoise[0] = pdir->tail[0];
// tortoise[1] = pdir->tail[1];
// tortoise_i = 0;
// tortoise_period *= 2;
// }
// tortoise_i += 1;
//
// if (lfs_pair_cmp(pdir->tail, pair) == 0) {
// return 0;
// }
//
// int err = lfs_dir_fetch(lfs, pdir, pdir->tail);
// if (err) {
// return err;
// }
// }
//
// return LFS_ERR_NOENT;
//}
//#endif
//
//#ifndef LFS_READONLY
//struct lfs_fs_parent_match {
// lfs_t *lfs;
// const lfs_block_t pair[2];
//};
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_fs_parent_match(void *data,
// lfs_tag_t tag, const void *buffer) {
// struct lfs_fs_parent_match *find = data;
// lfs_t *lfs = find->lfs;
// const struct lfs_diskoff *disk = buffer;
// (void)tag;
//
// lfs_block_t child[2];
// int err = lfs_bd_read(lfs,
// &lfs->pcache, &lfs->rcache, lfs->cfg->block_size,
// disk->block, disk->off, &child, sizeof(child));
// if (err) {
// return err;
// }
//
// lfs_pair_fromle32(child);
// return (lfs_pair_cmp(child, find->pair) == 0) ? LFS_CMP_EQ : LFS_CMP_LT;
//}
//#endif
//
//#ifndef LFS_READONLY
//static lfs_stag_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t pair[2],
// lfs_mdir_t *parent) {
// // use fetchmatch with callback to find pairs
// parent->tail[0] = 0;
// parent->tail[1] = 1;
// lfs_block_t tortoise[2] = {LFS_BLOCK_NULL, LFS_BLOCK_NULL};
// lfs_size_t tortoise_i = 1;
// lfs_size_t tortoise_period = 1;
// while (!lfs_pair_isnull(parent->tail)) {
// // detect cycles with Brent's algorithm
// if (lfs_pair_issync(parent->tail, tortoise)) {
// LFS_WARN("Cycle detected in tail list");
// return LFS_ERR_CORRUPT;
// }
// if (tortoise_i == tortoise_period) {
// tortoise[0] = parent->tail[0];
// tortoise[1] = parent->tail[1];
// tortoise_i = 0;
// tortoise_period *= 2;
// }
// tortoise_i += 1;
//
// lfs_stag_t tag = lfs_dir_fetchmatch(lfs, parent, parent->tail,
// LFS_MKTAG(0x7ff, 0, 0x3ff),
// LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 0, 8),
// NULL,
// lfs_fs_parent_match, &(struct lfs_fs_parent_match){
// lfs, {pair[0], pair[1]}});
// if (tag && tag != LFS_ERR_NOENT) {
// return tag;
// }
// }
//
// return LFS_ERR_NOENT;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_fs_preporphans(lfs_t *lfs, int8_t orphans) {
// LFS_ASSERT(lfs_tag_size(lfs->gstate.tag) > 0x000 || orphans >= 0);
// LFS_ASSERT(lfs_tag_size(lfs->gstate.tag) < 0x3ff || orphans <= 0);
// lfs->gstate.tag += orphans;
// lfs->gstate.tag = ((lfs->gstate.tag & ~LFS_MKTAG(0x800, 0, 0)) |
// ((uint32_t)lfs_gstate_hasorphans(&lfs->gstate) << 31));
//
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static void lfs_fs_prepmove(lfs_t *lfs,
// uint16_t id, const lfs_block_t pair[2]) {
// lfs->gstate.tag = ((lfs->gstate.tag & ~LFS_MKTAG(0x7ff, 0x3ff, 0)) |
// ((id != 0x3ff) ? LFS_MKTAG(LFS_TYPE_DELETE, id, 0) : 0));
// lfs->gstate.pair[0] = (id != 0x3ff) ? pair[0] : 0;
// lfs->gstate.pair[1] = (id != 0x3ff) ? pair[1] : 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_fs_demove(lfs_t *lfs) {
// if (!lfs_gstate_hasmove(&lfs->gdisk)) {
// return 0;
// }
//
// // Fix bad moves
// LFS_DEBUG("Fixing move {0x%"PRIx32", 0x%"PRIx32"} 0x%"PRIx16,
// lfs->gdisk.pair[0],
// lfs->gdisk.pair[1],
// lfs_tag_id(lfs->gdisk.tag));
//
// // no other gstate is supported at this time, so if we found something else
// // something most likely went wrong in gstate calculation
// LFS_ASSERT(lfs_tag_type3(lfs->gdisk.tag) == LFS_TYPE_DELETE);
//
// // fetch and delete the moved entry
// lfs_mdir_t movedir;
// int err = lfs_dir_fetch(lfs, &movedir, lfs->gdisk.pair);
// if (err) {
// return err;
// }
//
// // prep gstate and delete move id
// uint16_t moveid = lfs_tag_id(lfs->gdisk.tag);
// lfs_fs_prepmove(lfs, 0x3ff, NULL);
// err = lfs_dir_commit(lfs, &movedir, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_DELETE, moveid, 0), NULL}));
// if (err) {
// return err;
// }
//
// return 0;
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_fs_deorphan(lfs_t *lfs, bool powerloss) {
// if (!lfs_gstate_hasorphans(&lfs->gstate)) {
// return 0;
// }
//
// int8_t found = 0;
//
// // Check for orphans in two separate passes:
// // - 1 for half-orphans (relocations)
// // - 2 for full-orphans (removes/renames)
// //
// // Two separate passes are needed as half-orphans can contain outdated
// // references to full-orphans, effectively hiding them from the deorphan
// // search.
// //
// int pass = 0;
// while (pass < 2) {
// // Fix any orphans
// lfs_mdir_t pdir = {.split = true, .tail = {0, 1}};
// lfs_mdir_t dir;
// bool moreorphans = false;
//
// // iterate over all directory directory entries
// while (!lfs_pair_isnull(pdir.tail)) {
// int err = lfs_dir_fetch(lfs, &dir, pdir.tail);
// if (err) {
// return err;
// }
//
// // check head blocks for orphans
// if (!pdir.split) {
// // check if we have a parent
// lfs_mdir_t parent;
// lfs_stag_t tag = lfs_fs_parent(lfs, pdir.tail, &parent);
// if (tag < 0 && tag != LFS_ERR_NOENT) {
// return tag;
// }
//
// if (pass == 0 && tag != LFS_ERR_NOENT) {
// lfs_block_t pair[2];
// lfs_stag_t state = lfs_dir_get(lfs, &parent,
// LFS_MKTAG(0x7ff, 0x3ff, 0), tag, pair);
// if (state < 0) {
// return state;
// }
// lfs_pair_fromle32(pair);
//
// if (!lfs_pair_issync(pair, pdir.tail)) {
// // we have desynced
// LFS_DEBUG("Fixing half-orphan "
// "{0x%"PRIx32", 0x%"PRIx32"} "
// "-> {0x%"PRIx32", 0x%"PRIx32"}",
// pdir.tail[0], pdir.tail[1], pair[0], pair[1]);
//
// // fix pending move in this pair? this looks like an
// // optimization but is in fact _required_ since
// // relocating may outdate the move.
// uint16_t moveid = 0x3ff;
// if (lfs_gstate_hasmovehere(&lfs->gstate, pdir.pair)) {
// moveid = lfs_tag_id(lfs->gstate.tag);
// LFS_DEBUG("Fixing move while fixing orphans "
// "{0x%"PRIx32", 0x%"PRIx32"} 0x%"PRIx16"\n",
// pdir.pair[0], pdir.pair[1], moveid);
// lfs_fs_prepmove(lfs, 0x3ff, NULL);
// }
//
// lfs_pair_tole32(pair);
// state = lfs_dir_orphaningcommit(lfs, &pdir, LFS_MKATTRS(
// {LFS_MKTAG_IF(moveid != 0x3ff,
// LFS_TYPE_DELETE, moveid, 0), NULL},
// {LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8),
// pair}));
// lfs_pair_fromle32(pair);
// if (state < 0) {
// return state;
// }
//
// found += 1;
//
// // did our commit create more orphans?
// if (state == LFS_OK_ORPHANED) {
// moreorphans = true;
// }
//
// // refetch tail
// continue;
// }
// }
//
// // note we only check for full orphans if we may have had a
// // power-loss, otherwise orphans are created intentionally
// // during operations such as lfs_mkdir
// if (pass == 1 && tag == LFS_ERR_NOENT && powerloss) {
// // we are an orphan
// LFS_DEBUG("Fixing orphan {0x%"PRIx32", 0x%"PRIx32"}",
// pdir.tail[0], pdir.tail[1]);
//
// // steal state
// err = lfs_dir_getgstate(lfs, &dir, &lfs->gdelta);
// if (err) {
// return err;
// }
//
// // steal tail
// lfs_pair_tole32(dir.tail);
// int state = lfs_dir_orphaningcommit(lfs, &pdir, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_TAIL + dir.split, 0x3ff, 8),
// dir.tail}));
// lfs_pair_fromle32(dir.tail);
// if (state < 0) {
// return state;
// }
//
// found += 1;
//
// // did our commit create more orphans?
// if (state == LFS_OK_ORPHANED) {
// moreorphans = true;
// }
//
// // refetch tail
// continue;
// }
// }
//
// pdir = dir;
// }
//
// pass = moreorphans ? 0 : pass+1;
// }
//
// // mark orphans as fixed
// return lfs_fs_preporphans(lfs, -lfs_min(
// lfs_gstate_getorphans(&lfs->gstate),
// found));
//}
//#endif
//
//#ifndef LFS_READONLY
//static int lfs_fs_forceconsistency(lfs_t *lfs) {
// int err = lfs_fs_demove(lfs);
// if (err) {
// return err;
// }
//
// err = lfs_fs_deorphan(lfs, true);
// if (err) {
// return err;
// }
//
// return 0;
//}
//#endif
//
//static int lfs_fs_size_count(void *p, lfs_block_t block) {
// (void)block;
// lfs_size_t *size = p;
// *size += 1;
// return 0;
//}
//
//static lfs_ssize_t lfs_fs_rawsize(lfs_t *lfs) {
// lfs_size_t size = 0;
// int err = lfs_fs_rawtraverse(lfs, lfs_fs_size_count, &size, false);
// if (err) {
// return err;
// }
//
// return size;
//}
//
//#ifdef LFS_MIGRATE
//////// Migration from littelfs v1 below this //////
//
///// Version info ///
//
//// Software library version
//// Major (top-nibble), incremented on backwards incompatible changes
//// Minor (bottom-nibble), incremented on feature additions
//#define LFS1_VERSION 0x00010007
//#define LFS1_VERSION_MAJOR (0xffff & (LFS1_VERSION >> 16))
//#define LFS1_VERSION_MINOR (0xffff & (LFS1_VERSION >> 0))
//
//// Version of On-disk data structures
//// Major (top-nibble), incremented on backwards incompatible changes
//// Minor (bottom-nibble), incremented on feature additions
//#define LFS1_DISK_VERSION 0x00010001
//#define LFS1_DISK_VERSION_MAJOR (0xffff & (LFS1_DISK_VERSION >> 16))
//#define LFS1_DISK_VERSION_MINOR (0xffff & (LFS1_DISK_VERSION >> 0))
//
//
///// v1 Definitions ///
//
//// File types
//enum lfs1_type {
// LFS1_TYPE_REG = 0x11,
// LFS1_TYPE_DIR = 0x22,
// LFS1_TYPE_SUPERBLOCK = 0x2e,
//};
//
//typedef struct lfs1 {
// lfs_block_t root[2];
//} lfs1_t;
//
//typedef struct lfs1_entry {
// lfs_off_t off;
//
// struct lfs1_disk_entry {
// uint8_t type;
// uint8_t elen;
// uint8_t alen;
// uint8_t nlen;
// union {
// struct {
// lfs_block_t head;
// lfs_size_t size;
// } file;
// lfs_block_t dir[2];
// } u;
// } d;
//} lfs1_entry_t;
//
//typedef struct lfs1_dir {
// struct lfs1_dir *next;
// lfs_block_t pair[2];
// lfs_off_t off;
//
// lfs_block_t head[2];
// lfs_off_t pos;
//
// struct lfs1_disk_dir {
// uint32_t rev;
// lfs_size_t size;
// lfs_block_t tail[2];
// } d;
//} lfs1_dir_t;
//
//typedef struct lfs1_superblock {
// lfs_off_t off;
//
// struct lfs1_disk_superblock {
// uint8_t type;
// uint8_t elen;
// uint8_t alen;
// uint8_t nlen;
// lfs_block_t root[2];
// uint32_t block_size;
// uint32_t block_count;
// uint32_t version;
// char magic[8];
// } d;
//} lfs1_superblock_t;
//
//
///// Low-level wrappers v1->v2 ///
//static void lfs1_crc(uint32_t *crc, const void *buffer, size_t size) {
// *crc = lfs_crc(*crc, buffer, size);
//}
//
//static int lfs1_bd_read(lfs_t *lfs, lfs_block_t block,
// lfs_off_t off, void *buffer, lfs_size_t size) {
// // if we ever do more than writes to alternating pairs,
// // this may need to consider pcache
// return lfs_bd_read(lfs, &lfs->pcache, &lfs->rcache, size,
// block, off, buffer, size);
//}
//
//static int lfs1_bd_crc(lfs_t *lfs, lfs_block_t block,
// lfs_off_t off, lfs_size_t size, uint32_t *crc) {
// for (lfs_off_t i = 0; i < size; i++) {
// uint8_t c;
// int err = lfs1_bd_read(lfs, block, off+i, &c, 1);
// if (err) {
// return err;
// }
//
// lfs1_crc(crc, &c, 1);
// }
//
// return 0;
//}
//
//
///// Endian swapping functions ///
//static void lfs1_dir_fromle32(struct lfs1_disk_dir *d) {
// d->rev = lfs_fromle32(d->rev);
// d->size = lfs_fromle32(d->size);
// d->tail[0] = lfs_fromle32(d->tail[0]);
// d->tail[1] = lfs_fromle32(d->tail[1]);
//}
//
//static void lfs1_dir_tole32(struct lfs1_disk_dir *d) {
// d->rev = lfs_tole32(d->rev);
// d->size = lfs_tole32(d->size);
// d->tail[0] = lfs_tole32(d->tail[0]);
// d->tail[1] = lfs_tole32(d->tail[1]);
//}
//
//static void lfs1_entry_fromle32(struct lfs1_disk_entry *d) {
// d->u.dir[0] = lfs_fromle32(d->u.dir[0]);
// d->u.dir[1] = lfs_fromle32(d->u.dir[1]);
//}
//
//static void lfs1_entry_tole32(struct lfs1_disk_entry *d) {
// d->u.dir[0] = lfs_tole32(d->u.dir[0]);
// d->u.dir[1] = lfs_tole32(d->u.dir[1]);
//}
//
//static void lfs1_superblock_fromle32(struct lfs1_disk_superblock *d) {
// d->root[0] = lfs_fromle32(d->root[0]);
// d->root[1] = lfs_fromle32(d->root[1]);
// d->block_size = lfs_fromle32(d->block_size);
// d->block_count = lfs_fromle32(d->block_count);
// d->version = lfs_fromle32(d->version);
//}
//
//
/////// Metadata pair and directory operations ///
//static inline lfs_size_t lfs1_entry_size(const lfs1_entry_t *entry) {
// return 4 + entry->d.elen + entry->d.alen + entry->d.nlen;
//}
//
//static int lfs1_dir_fetch(lfs_t *lfs,
// lfs1_dir_t *dir, const lfs_block_t pair[2]) {
// // copy out pair, otherwise may be aliasing dir
// const lfs_block_t tpair[2] = {pair[0], pair[1]};
// bool valid = false;
//
// // check both blocks for the most recent revision
// for (int i = 0; i < 2; i++) {
// struct lfs1_disk_dir test;
// int err = lfs1_bd_read(lfs, tpair[i], 0, &test, sizeof(test));
// lfs1_dir_fromle32(&test);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// continue;
// }
// return err;
// }
//
// if (valid && lfs_scmp(test.rev, dir->d.rev) < 0) {
// continue;
// }
//
// if ((0x7fffffff & test.size) < sizeof(test)+4 ||
// (0x7fffffff & test.size) > lfs->cfg->block_size) {
// continue;
// }
//
// uint32_t crc = 0xffffffff;
// lfs1_dir_tole32(&test);
// lfs1_crc(&crc, &test, sizeof(test));
// lfs1_dir_fromle32(&test);
// err = lfs1_bd_crc(lfs, tpair[i], sizeof(test),
// (0x7fffffff & test.size) - sizeof(test), &crc);
// if (err) {
// if (err == LFS_ERR_CORRUPT) {
// continue;
// }
// return err;
// }
//
// if (crc != 0) {
// continue;
// }
//
// valid = true;
//
// // setup dir in case it's valid
// dir->pair[0] = tpair[(i+0) % 2];
// dir->pair[1] = tpair[(i+1) % 2];
// dir->off = sizeof(dir->d);
// dir->d = test;
// }
//
// if (!valid) {
// LFS_ERROR("Corrupted dir pair at {0x%"PRIx32", 0x%"PRIx32"}",
// tpair[0], tpair[1]);
// return LFS_ERR_CORRUPT;
// }
//
// return 0;
//}
//
//static int lfs1_dir_next(lfs_t *lfs, lfs1_dir_t *dir, lfs1_entry_t *entry) {
// while (dir->off + sizeof(entry->d) > (0x7fffffff & dir->d.size)-4) {
// if (!(0x80000000 & dir->d.size)) {
// entry->off = dir->off;
// return LFS_ERR_NOENT;
// }
//
// int err = lfs1_dir_fetch(lfs, dir, dir->d.tail);
// if (err) {
// return err;
// }
//
// dir->off = sizeof(dir->d);
// dir->pos += sizeof(dir->d) + 4;
// }
//
// int err = lfs1_bd_read(lfs, dir->pair[0], dir->off,
// &entry->d, sizeof(entry->d));
// lfs1_entry_fromle32(&entry->d);
// if (err) {
// return err;
// }
//
// entry->off = dir->off;
// dir->off += lfs1_entry_size(entry);
// dir->pos += lfs1_entry_size(entry);
// return 0;
//}
//
///// littlefs v1 specific operations ///
//int lfs1_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data) {
// if (lfs_pair_isnull(lfs->lfs1->root)) {
// return 0;
// }
//
// // iterate over metadata pairs
// lfs1_dir_t dir;
// lfs1_entry_t entry;
// lfs_block_t cwd[2] = {0, 1};
//
// while (true) {
// for (int i = 0; i < 2; i++) {
// int err = cb(data, cwd[i]);
// if (err) {
// return err;
// }
// }
//
// int err = lfs1_dir_fetch(lfs, &dir, cwd);
// if (err) {
// return err;
// }
//
// // iterate over contents
// while (dir.off + sizeof(entry.d) <= (0x7fffffff & dir.d.size)-4) {
// err = lfs1_bd_read(lfs, dir.pair[0], dir.off,
// &entry.d, sizeof(entry.d));
// lfs1_entry_fromle32(&entry.d);
// if (err) {
// return err;
// }
//
// dir.off += lfs1_entry_size(&entry);
// if ((0x70 & entry.d.type) == (0x70 & LFS1_TYPE_REG)) {
// err = lfs_ctz_traverse(lfs, NULL, &lfs->rcache,
// entry.d.u.file.head, entry.d.u.file.size, cb, data);
// if (err) {
// return err;
// }
// }
// }
//
// // we also need to check if we contain a threaded v2 directory
// lfs_mdir_t dir2 = {.split=true, .tail={cwd[0], cwd[1]}};
// while (dir2.split) {
// err = lfs_dir_fetch(lfs, &dir2, dir2.tail);
// if (err) {
// break;
// }
//
// for (int i = 0; i < 2; i++) {
// err = cb(data, dir2.pair[i]);
// if (err) {
// return err;
// }
// }
// }
//
// cwd[0] = dir.d.tail[0];
// cwd[1] = dir.d.tail[1];
//
// if (lfs_pair_isnull(cwd)) {
// break;
// }
// }
//
// return 0;
//}
//
//static int lfs1_moved(lfs_t *lfs, const void *e) {
// if (lfs_pair_isnull(lfs->lfs1->root)) {
// return 0;
// }
//
// // skip superblock
// lfs1_dir_t cwd;
// int err = lfs1_dir_fetch(lfs, &cwd, (const lfs_block_t[2]){0, 1});
// if (err) {
// return err;
// }
//
// // iterate over all directory directory entries
// lfs1_entry_t entry;
// while (!lfs_pair_isnull(cwd.d.tail)) {
// err = lfs1_dir_fetch(lfs, &cwd, cwd.d.tail);
// if (err) {
// return err;
// }
//
// while (true) {
// err = lfs1_dir_next(lfs, &cwd, &entry);
// if (err && err != LFS_ERR_NOENT) {
// return err;
// }
//
// if (err == LFS_ERR_NOENT) {
// break;
// }
//
// if (!(0x80 & entry.d.type) &&
// memcmp(&entry.d.u, e, sizeof(entry.d.u)) == 0) {
// return true;
// }
// }
// }
//
// return false;
//}
//
///// Filesystem operations ///
//static int lfs1_mount(lfs_t *lfs, struct lfs1 *lfs1,
// const struct lfs_config *cfg) {
// int err = 0;
// {
// err = lfs_init(lfs, cfg);
// if (err) {
// return err;
// }
//
// lfs->lfs1 = lfs1;
// lfs->lfs1->root[0] = LFS_BLOCK_NULL;
// lfs->lfs1->root[1] = LFS_BLOCK_NULL;
//
// // setup free lookahead
// lfs->free.off = 0;
// lfs->free.size = 0;
// lfs->free.i = 0;
// lfs_alloc_ack(lfs);
//
// // load superblock
// lfs1_dir_t dir;
// lfs1_superblock_t superblock;
// err = lfs1_dir_fetch(lfs, &dir, (const lfs_block_t[2]){0, 1});
// if (err && err != LFS_ERR_CORRUPT) {
// goto cleanup;
// }
//
// if (!err) {
// err = lfs1_bd_read(lfs, dir.pair[0], sizeof(dir.d),
// &superblock.d, sizeof(superblock.d));
// lfs1_superblock_fromle32(&superblock.d);
// if (err) {
// goto cleanup;
// }
//
// lfs->lfs1->root[0] = superblock.d.root[0];
// lfs->lfs1->root[1] = superblock.d.root[1];
// }
//
// if (err || memcmp(superblock.d.magic, "littlefs", 8) != 0) {
// LFS_ERROR("Invalid superblock at {0x%"PRIx32", 0x%"PRIx32"}",
// 0, 1);
// err = LFS_ERR_CORRUPT;
// goto cleanup;
// }
//
// uint16_t major_version = (0xffff & (superblock.d.version >> 16));
// uint16_t minor_version = (0xffff & (superblock.d.version >> 0));
// if ((major_version != LFS1_DISK_VERSION_MAJOR ||
// minor_version > LFS1_DISK_VERSION_MINOR)) {
// LFS_ERROR("Invalid version v%d.%d", major_version, minor_version);
// err = LFS_ERR_INVAL;
// goto cleanup;
// }
//
// return 0;
// }
//
//cleanup:
// lfs_deinit(lfs);
// return err;
//}
//
//static int lfs1_unmount(lfs_t *lfs) {
// return lfs_deinit(lfs);
//}
//
///// v1 migration ///
//static int lfs_rawmigrate(lfs_t *lfs, const struct lfs_config *cfg) {
// struct lfs1 lfs1;
// int err = lfs1_mount(lfs, &lfs1, cfg);
// if (err) {
// return err;
// }
//
// {
// // iterate through each directory, copying over entries
// // into new directory
// lfs1_dir_t dir1;
// lfs_mdir_t dir2;
// dir1.d.tail[0] = lfs->lfs1->root[0];
// dir1.d.tail[1] = lfs->lfs1->root[1];
// while (!lfs_pair_isnull(dir1.d.tail)) {
// // iterate old dir
// err = lfs1_dir_fetch(lfs, &dir1, dir1.d.tail);
// if (err) {
// goto cleanup;
// }
//
// // create new dir and bind as temporary pretend root
// err = lfs_dir_alloc(lfs, &dir2);
// if (err) {
// goto cleanup;
// }
//
// dir2.rev = dir1.d.rev;
// dir1.head[0] = dir1.pair[0];
// dir1.head[1] = dir1.pair[1];
// lfs->root[0] = dir2.pair[0];
// lfs->root[1] = dir2.pair[1];
//
// err = lfs_dir_commit(lfs, &dir2, NULL, 0);
// if (err) {
// goto cleanup;
// }
//
// while (true) {
// lfs1_entry_t entry1;
// err = lfs1_dir_next(lfs, &dir1, &entry1);
// if (err && err != LFS_ERR_NOENT) {
// goto cleanup;
// }
//
// if (err == LFS_ERR_NOENT) {
// break;
// }
//
// // check that entry has not been moved
// if (entry1.d.type & 0x80) {
// int moved = lfs1_moved(lfs, &entry1.d.u);
// if (moved < 0) {
// err = moved;
// goto cleanup;
// }
//
// if (moved) {
// continue;
// }
//
// entry1.d.type &= ~0x80;
// }
//
// // also fetch name
// char name[LFS_NAME_MAX+1];
// memset(name, 0, sizeof(name));
// err = lfs1_bd_read(lfs, dir1.pair[0],
// entry1.off + 4+entry1.d.elen+entry1.d.alen,
// name, entry1.d.nlen);
// if (err) {
// goto cleanup;
// }
//
// bool isdir = (entry1.d.type == LFS1_TYPE_DIR);
//
// // create entry in new dir
// err = lfs_dir_fetch(lfs, &dir2, lfs->root);
// if (err) {
// goto cleanup;
// }
//
// uint16_t id;
// err = lfs_dir_find(lfs, &dir2, &(const char*){name}, &id);
// if (!(err == LFS_ERR_NOENT && id != 0x3ff)) {
// err = (err < 0) ? err : LFS_ERR_EXIST;
// goto cleanup;
// }
//
// lfs1_entry_tole32(&entry1.d);
// err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_CREATE, id, 0), NULL},
// {LFS_MKTAG_IF_ELSE(isdir,
// LFS_TYPE_DIR, id, entry1.d.nlen,
// LFS_TYPE_REG, id, entry1.d.nlen),
// name},
// {LFS_MKTAG_IF_ELSE(isdir,
// LFS_TYPE_DIRSTRUCT, id, sizeof(entry1.d.u),
// LFS_TYPE_CTZSTRUCT, id, sizeof(entry1.d.u)),
// &entry1.d.u}));
// lfs1_entry_fromle32(&entry1.d);
// if (err) {
// goto cleanup;
// }
// }
//
// if (!lfs_pair_isnull(dir1.d.tail)) {
// // find last block and update tail to thread into fs
// err = lfs_dir_fetch(lfs, &dir2, lfs->root);
// if (err) {
// goto cleanup;
// }
//
// while (dir2.split) {
// err = lfs_dir_fetch(lfs, &dir2, dir2.tail);
// if (err) {
// goto cleanup;
// }
// }
//
// lfs_pair_tole32(dir2.pair);
// err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8), dir1.d.tail}));
// lfs_pair_fromle32(dir2.pair);
// if (err) {
// goto cleanup;
// }
// }
//
// // Copy over first block to thread into fs. Unfortunately
// // if this fails there is not much we can do.
// LFS_DEBUG("Migrating {0x%"PRIx32", 0x%"PRIx32"} "
// "-> {0x%"PRIx32", 0x%"PRIx32"}",
// lfs->root[0], lfs->root[1], dir1.head[0], dir1.head[1]);
//
// err = lfs_bd_erase(lfs, dir1.head[1]);
// if (err) {
// goto cleanup;
// }
//
// err = lfs_dir_fetch(lfs, &dir2, lfs->root);
// if (err) {
// goto cleanup;
// }
//
// for (lfs_off_t i = 0; i < dir2.off; i++) {
// uint8_t dat;
// err = lfs_bd_read(lfs,
// NULL, &lfs->rcache, dir2.off,
// dir2.pair[0], i, &dat, 1);
// if (err) {
// goto cleanup;
// }
//
// err = lfs_bd_prog(lfs,
// &lfs->pcache, &lfs->rcache, true,
// dir1.head[1], i, &dat, 1);
// if (err) {
// goto cleanup;
// }
// }
//
// err = lfs_bd_flush(lfs, &lfs->pcache, &lfs->rcache, true);
// if (err) {
// goto cleanup;
// }
// }
//
// // Create new superblock. This marks a successful migration!
// err = lfs1_dir_fetch(lfs, &dir1, (const lfs_block_t[2]){0, 1});
// if (err) {
// goto cleanup;
// }
//
// dir2.pair[0] = dir1.pair[0];
// dir2.pair[1] = dir1.pair[1];
// dir2.rev = dir1.d.rev;
// dir2.off = sizeof(dir2.rev);
// dir2.etag = 0xffffffff;
// dir2.count = 0;
// dir2.tail[0] = lfs->lfs1->root[0];
// dir2.tail[1] = lfs->lfs1->root[1];
// dir2.erased = false;
// dir2.split = true;
//
// lfs_superblock_t superblock = {
// .version = LFS_DISK_VERSION,
// .block_size = lfs->cfg->block_size,
// .block_count = lfs->cfg->block_count,
// .name_max = lfs->name_max,
// .file_max = lfs->file_max,
// .attr_max = lfs->attr_max,
// };
//
// lfs_superblock_tole32(&superblock);
// err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
// {LFS_MKTAG(LFS_TYPE_CREATE, 0, 0), NULL},
// {LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
// {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
// &superblock}));
// if (err) {
// goto cleanup;
// }
//
// // sanity check that fetch works
// err = lfs_dir_fetch(lfs, &dir2, (const lfs_block_t[2]){0, 1});
// if (err) {
// goto cleanup;
// }
//
// // force compaction to prevent accidentally mounting v1
// dir2.erased = false;
// err = lfs_dir_commit(lfs, &dir2, NULL, 0);
// if (err) {
// goto cleanup;
// }
// }
//
//cleanup:
// lfs1_unmount(lfs);
// return err;
//}
//
//#endif
//
//
///// Public API wrappers ///
//
//// Here we can add tracing/thread safety easily
//
//// Thread-safe wrappers if enabled
//#ifdef LFS_THREADSAFE
//#define LFS_LOCK(cfg) cfg->lock(cfg)
//#define LFS_UNLOCK(cfg) cfg->unlock(cfg)
//#else
//#define LFS_LOCK(cfg) ((void)cfg, 0)
//#define LFS_UNLOCK(cfg) ((void)cfg)
//#endif
//
//// Public API
//#ifndef LFS_READONLY
//int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
// int err = LFS_LOCK(cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_format(%p, %p {.context=%p, "
// ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
// ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
// ".block_size=%"PRIu32", .block_count=%"PRIu32", "
// ".block_cycles=%"PRIu32", .cache_size=%"PRIu32", "
// ".lookahead_size=%"PRIu32", .read_buffer=%p, "
// ".prog_buffer=%p, .lookahead_buffer=%p, "
// ".name_max=%"PRIu32", .file_max=%"PRIu32", "
// ".attr_max=%"PRIu32"})",
// (void*)lfs, (void*)cfg, cfg->context,
// (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
// (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
// cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
// cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
// cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
// cfg->name_max, cfg->file_max, cfg->attr_max);
//
// err = lfs_rawformat(lfs, cfg);
//
// LFS_TRACE("lfs_format -> %d", err);
// LFS_UNLOCK(cfg);
// return err;
//}
//#endif
//
//int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
// int err = LFS_LOCK(cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_mount(%p, %p {.context=%p, "
// ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
// ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
// ".block_size=%"PRIu32", .block_count=%"PRIu32", "
// ".block_cycles=%"PRIu32", .cache_size=%"PRIu32", "
// ".lookahead_size=%"PRIu32", .read_buffer=%p, "
// ".prog_buffer=%p, .lookahead_buffer=%p, "
// ".name_max=%"PRIu32", .file_max=%"PRIu32", "
// ".attr_max=%"PRIu32"})",
// (void*)lfs, (void*)cfg, cfg->context,
// (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
// (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
// cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
// cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
// cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
// cfg->name_max, cfg->file_max, cfg->attr_max);
//
// err = lfs_rawmount(lfs, cfg);
//
// LFS_TRACE("lfs_mount -> %d", err);
// LFS_UNLOCK(cfg);
// return err;
//}
//
//int lfs_unmount(lfs_t *lfs) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_unmount(%p)", (void*)lfs);
//
// err = lfs_rawunmount(lfs);
//
// LFS_TRACE("lfs_unmount -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//#ifndef LFS_READONLY
//int lfs_remove(lfs_t *lfs, const char *path) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_remove(%p, \"%s\")", (void*)lfs, path);
//
// err = lfs_rawremove(lfs, path);
//
// LFS_TRACE("lfs_remove -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//#ifndef LFS_READONLY
//int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_rename(%p, \"%s\", \"%s\")", (void*)lfs, oldpath, newpath);
//
// err = lfs_rawrename(lfs, oldpath, newpath);
//
// LFS_TRACE("lfs_rename -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_stat(%p, \"%s\", %p)", (void*)lfs, path, (void*)info);
//
// err = lfs_rawstat(lfs, path, info);
//
// LFS_TRACE("lfs_stat -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
// uint8_t type, void *buffer, lfs_size_t size) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_getattr(%p, \"%s\", %"PRIu8", %p, %"PRIu32")",
// (void*)lfs, path, type, buffer, size);
//
// lfs_ssize_t res = lfs_rawgetattr(lfs, path, type, buffer, size);
//
// LFS_TRACE("lfs_getattr -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//
//#ifndef LFS_READONLY
//int lfs_setattr(lfs_t *lfs, const char *path,
// uint8_t type, const void *buffer, lfs_size_t size) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_setattr(%p, \"%s\", %"PRIu8", %p, %"PRIu32")",
// (void*)lfs, path, type, buffer, size);
//
// err = lfs_rawsetattr(lfs, path, type, buffer, size);
//
// LFS_TRACE("lfs_setattr -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//#ifndef LFS_READONLY
//int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_removeattr(%p, \"%s\", %"PRIu8")", (void*)lfs, path, type);
//
// err = lfs_rawremoveattr(lfs, path, type);
//
// LFS_TRACE("lfs_removeattr -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//#ifndef LFS_NO_MALLOC
//int lfs_file_open(lfs_t *lfs, lfs_file_t *file, const char *path, int flags) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_open(%p, %p, \"%s\", %x)",
// (void*)lfs, (void*)file, path, flags);
// LFS_ASSERT(!lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// err = lfs_file_rawopen(lfs, file, path, flags);
//
// LFS_TRACE("lfs_file_open -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
// const char *path, int flags,
// const struct lfs_file_config *cfg) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_opencfg(%p, %p, \"%s\", %x, %p {"
// ".buffer=%p, .attrs=%p, .attr_count=%"PRIu32"})",
// (void*)lfs, (void*)file, path, flags,
// (void*)cfg, cfg->buffer, (void*)cfg->attrs, cfg->attr_count);
// LFS_ASSERT(!lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// err = lfs_file_rawopencfg(lfs, file, path, flags, cfg);
//
// LFS_TRACE("lfs_file_opencfg -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_close(%p, %p)", (void*)lfs, (void*)file);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// err = lfs_file_rawclose(lfs, file);
//
// LFS_TRACE("lfs_file_close -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//#ifndef LFS_READONLY
//int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_sync(%p, %p)", (void*)lfs, (void*)file);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// err = lfs_file_rawsync(lfs, file);
//
// LFS_TRACE("lfs_file_sync -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
// void *buffer, lfs_size_t size) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_read(%p, %p, %p, %"PRIu32")",
// (void*)lfs, (void*)file, buffer, size);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// lfs_ssize_t res = lfs_file_rawread(lfs, file, buffer, size);
//
// LFS_TRACE("lfs_file_read -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//
//#ifndef LFS_READONLY
//lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
// const void *buffer, lfs_size_t size) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_write(%p, %p, %p, %"PRIu32")",
// (void*)lfs, (void*)file, buffer, size);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// lfs_ssize_t res = lfs_file_rawwrite(lfs, file, buffer, size);
//
// LFS_TRACE("lfs_file_write -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//#endif
//
//lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
// lfs_soff_t off, int whence) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_seek(%p, %p, %"PRId32", %d)",
// (void*)lfs, (void*)file, off, whence);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// lfs_soff_t res = lfs_file_rawseek(lfs, file, off, whence);
//
// LFS_TRACE("lfs_file_seek -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//
//#ifndef LFS_READONLY
//int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_truncate(%p, %p, %"PRIu32")",
// (void*)lfs, (void*)file, size);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// err = lfs_file_rawtruncate(lfs, file, size);
//
// LFS_TRACE("lfs_file_truncate -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_tell(%p, %p)", (void*)lfs, (void*)file);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// lfs_soff_t res = lfs_file_rawtell(lfs, file);
//
// LFS_TRACE("lfs_file_tell -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//
//int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_rewind(%p, %p)", (void*)lfs, (void*)file);
//
// err = lfs_file_rawrewind(lfs, file);
//
// LFS_TRACE("lfs_file_rewind -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_file_size(%p, %p)", (void*)lfs, (void*)file);
// LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
//
// lfs_soff_t res = lfs_file_rawsize(lfs, file);
//
// LFS_TRACE("lfs_file_size -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//
//#ifndef LFS_READONLY
//int lfs_mkdir(lfs_t *lfs, const char *path) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_mkdir(%p, \"%s\")", (void*)lfs, path);
//
// err = lfs_rawmkdir(lfs, path);
//
// LFS_TRACE("lfs_mkdir -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//#endif
//
//int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_dir_open(%p, %p, \"%s\")", (void*)lfs, (void*)dir, path);
// LFS_ASSERT(!lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)dir));
//
// err = lfs_dir_rawopen(lfs, dir, path);
//
// LFS_TRACE("lfs_dir_open -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_dir_close(%p, %p)", (void*)lfs, (void*)dir);
//
// err = lfs_dir_rawclose(lfs, dir);
//
// LFS_TRACE("lfs_dir_close -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//int lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_dir_read(%p, %p, %p)",
// (void*)lfs, (void*)dir, (void*)info);
//
// err = lfs_dir_rawread(lfs, dir, info);
//
// LFS_TRACE("lfs_dir_read -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//int lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_dir_seek(%p, %p, %"PRIu32")",
// (void*)lfs, (void*)dir, off);
//
// err = lfs_dir_rawseek(lfs, dir, off);
//
// LFS_TRACE("lfs_dir_seek -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//lfs_soff_t lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_dir_tell(%p, %p)", (void*)lfs, (void*)dir);
//
// lfs_soff_t res = lfs_dir_rawtell(lfs, dir);
//
// LFS_TRACE("lfs_dir_tell -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//
//int lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_dir_rewind(%p, %p)", (void*)lfs, (void*)dir);
//
// err = lfs_dir_rawrewind(lfs, dir);
//
// LFS_TRACE("lfs_dir_rewind -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//lfs_ssize_t lfs_fs_size(lfs_t *lfs) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_fs_size(%p)", (void*)lfs);
//
// lfs_ssize_t res = lfs_fs_rawsize(lfs);
//
// LFS_TRACE("lfs_fs_size -> %"PRId32, res);
// LFS_UNLOCK(lfs->cfg);
// return res;
//}
//
//int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void *, lfs_block_t), void *data) {
// int err = LFS_LOCK(lfs->cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_fs_traverse(%p, %p, %p)",
// (void*)lfs, (void*)(uintptr_t)cb, data);
//
// err = lfs_fs_rawtraverse(lfs, cb, data, true);
//
// LFS_TRACE("lfs_fs_traverse -> %d", err);
// LFS_UNLOCK(lfs->cfg);
// return err;
//}
//
//#ifdef LFS_MIGRATE
//int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
// int err = LFS_LOCK(cfg);
// if (err) {
// return err;
// }
// LFS_TRACE("lfs_migrate(%p, %p {.context=%p, "
// ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
// ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
// ".block_size=%"PRIu32", .block_count=%"PRIu32", "
// ".block_cycles=%"PRIu32", .cache_size=%"PRIu32", "
// ".lookahead_size=%"PRIu32", .read_buffer=%p, "
// ".prog_buffer=%p, .lookahead_buffer=%p, "
// ".name_max=%"PRIu32", .file_max=%"PRIu32", "
// ".attr_max=%"PRIu32"})",
// (void*)lfs, (void*)cfg, cfg->context,
// (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
// (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
// cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
// cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
// cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
// cfg->name_max, cfg->file_max, cfg->attr_max);
//
// err = lfs_rawmigrate(lfs, cfg);
//
// LFS_TRACE("lfs_migrate -> %d", err);
// LFS_UNLOCK(cfg);
// return err;
//}
//#endif
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