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64a1b46ea2bfc39fe8cbc45838b5892eb655538a
littlefs/lfs.c
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Christopher Haster 64a1b46ea2 Renamed a couple directory related things 
- dstart -> bookmark
- *dnamelookup -> *namelookup
2023-08-07 14:00:44 -05:00

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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_off_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_off_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_off_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_off_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_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;
}
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_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, 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) {
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;
}
}
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);
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_off_t off,
const void *buffer, lfs_size_t size) {
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_off_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);
if (err) {
return err;
}
}
continue;
}
// pcache must have been flushed, either by programming and
// entire block or manually flushing the pcache
LFS_ASSERT(pcache->block == LFS_BLOCK_NULL);
// prepare pcache, first condition can no longer fail
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
LFS_ASSERT(lfs->pcache.block != block);
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_off_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_readcsum/lfsr_bd_csum somehow?
static int lfsr_bd_readcsum(lfs_t *lfs,
lfs_block_t block, lfs_off_t off, lfs_size_t hint,
void *buffer, lfs_size_t size,
uint32_t *csum_) {
int err = lfsr_bd_read(lfs, block, off, hint, buffer, size);
if (err) {
return err;
}
*csum_ = lfs_crc32c(*csum_, buffer, size);
return 0;
}
static int lfsr_bd_csum(lfs_t *lfs,
lfs_block_t block, lfs_off_t off, lfs_size_t hint, lfs_size_t size,
uint32_t *crc_) {
// 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, crc_);
}
static lfs_scmp_t lfsr_bd_cmp(lfs_t *lfs,
lfs_block_t block, lfs_off_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_off_t off,
const void *buffer, lfs_size_t size,
uint32_t *csum_) {
// 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, false,
block, off, buffer, size);
if (err) {
return err;
}
// optional checksum
if (csum_) {
*csum_ = lfs_crc32c(*csum_, buffer, size);
}
return 0;
}
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_off_t off,
const void *buffer, lfs_size_t size,
uint32_t *csum_) {
// 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);
if (err) {
return err;
}
if (csum_) {
*csum_ = lfs_crc32c(*csum_, 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_type {
LFSR_TAG_NULL = 0x0000,
LFSR_TAG_UNR = 0x1000, // in-device only
LFSR_TAG_GROW = 0x3000, // in-device only
LFSR_TAG_SUPERMAGIC = 0x0003,
LFSR_TAG_SUPERCONFIG = 0x0004,
LFSR_TAG_GSTATE = 0x0100,
LFSR_TAG_GRM = 0x0100,
LFSR_TAG_RMGRM = 0x1100, // in-device only
LFSR_TAG_NAME = 0x0200,
LFSR_TAG_WIDENAME = 0x4200, // in-device only
LFSR_TAG_BRANCH = 0x0200,
LFSR_TAG_BOOKMARK = 0x0201,
LFSR_TAG_REG = 0x0202,
LFSR_TAG_GROWREG = 0x2202, // test only? TODO
LFSR_TAG_DIR = 0x0203,
LFSR_TAG_STRUCT = 0x0300,
LFSR_TAG_WIDESTRUCT = 0x4300, // in-device only
LFSR_TAG_RMWIDESTRUCT = 0x5300, // in-device only
LFSR_TAG_INLINED = 0x0300,
LFSR_TAG_BLOCK = 0x0302,
LFSR_TAG_BTREE = 0x0303,
LFSR_TAG_RMBTREE = 0x1303, // in-device only
LFSR_TAG_MROOT = 0x0304,
LFSR_TAG_MDIR = 0x0305,
LFSR_TAG_RMMDIR = 0x1305, // in-device only
LFSR_TAG_MTREE = 0x0306,
LFSR_TAG_RMMTREE = 0x1306, // in-device only
LFSR_TAG_DID = 0x0307,
LFSR_TAG_UATTR = 0x0400,
LFSR_TAG_WIDEUATTR = 0x4400, // test only? TODO
LFSR_TAG_GROWUATTR = 0x2400, // test only? TODO
LFSR_TAG_RMUATTR = 0x1400, // in-device only
LFSR_TAG_RMWIDEUATTR = 0x5400, // test only? TODO
LFSR_TAG_SATTR = 0x0500, // test only? TODO
LFSR_TAG_RMWIDESATTR = 0x5500, // in-device only
LFSR_TAG_ALT = 0x4000,
LFSR_TAG_ALTLE = 0x4000,
LFSR_TAG_ALTBLE = 0x4000,
LFSR_TAG_ALTRLE = 0x5000,
LFSR_TAG_ALTGT = 0x6000,
LFSR_TAG_ALTBGT = 0x6000,
LFSR_TAG_ALTRGT = 0x7000,
LFSR_TAG_CRC = 0x2000,
LFSR_TAG_FCRC = 0x2100,
// in-device only
LFSR_TAG_MOVE = 0x0800,
};
#define LFSR_TAG_ALTLE(red, key) \
(LFSR_TAG_ALTLE \
| ((0x1 & (lfsr_tag_t)(red)) << 12) \
| (0x0fff & (lfsr_tag_t)(key)))
#define LFSR_TAG_ALTGT(red, key) \
(LFSR_TAG_ALTGT \
| ((0x1 & (lfsr_tag_t)(red)) << 12) \
| (0x0fff & (lfsr_tag_t)(key)))
#define LFSR_TAG_UATTR(attr) \
(LFSR_TAG_UATTR \
| (0x7f & (lfsr_tag_t)(attr)))
// TODO test only?
#define LFSR_TAG_WIDEUATTR(attr) \
(LFSR_TAG_WIDEUATTR \
| (0x7f & (lfsr_tag_t)(attr)))
// TODO test only?
#define LFSR_TAG_GROWUATTR(attr) \
(LFSR_TAG_GROWUATTR \
| (0x7f & (lfsr_tag_t)(attr)))
#define LFSR_TAG_RMUATTR(attr) \
(LFSR_TAG_RMUATTR \
| (0x7f & (lfsr_tag_t)(attr)))
// TODO test only?
#define LFSR_TAG_SATTR(attr) \
(LFSR_TAG_SATTR \
| (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 bool lfsr_tag_isvalid(lfsr_tag_t tag) {
return !(tag & 0x8000);
}
static inline lfsr_tag_t lfsr_tag_setvalid(lfsr_tag_t tag) {
return tag & ~0x8000;
}
static inline lfsr_tag_t lfsr_tag_setinvalid(lfsr_tag_t tag) {
return tag | 0x8000;
}
static inline bool lfsr_tag_iswide(lfsr_tag_t tag) {
return tag & 0x4000;
}
static inline lfsr_tag_t lfsr_tag_setwide(lfsr_tag_t tag) {
return tag | 0x4000;
}
static inline lfsr_tag_t lfsr_tag_clearwide(lfsr_tag_t tag) {
return tag & ~0x4000;
}
static inline bool lfsr_tag_isgrow(lfsr_tag_t tag) {
return tag & 0x2000;
}
static inline lfsr_tag_t lfsr_tag_setgrow(lfsr_tag_t tag) {
return tag | 0x2000;
}
static inline lfsr_tag_t lfsr_tag_cleargrow(lfsr_tag_t tag) {
return tag & ~0x2000;
}
static inline bool lfsr_tag_isrm(lfsr_tag_t tag) {
return tag & 0x1000;
}
static inline lfsr_tag_t lfsr_tag_setrm(lfsr_tag_t tag) {
return tag | 0x1000;
}
static inline bool lfsr_tag_isalt(lfsr_tag_t tag) {
return tag & 0x4000;
}
static inline bool lfsr_tag_istrunk(lfsr_tag_t tag) {
return (tag & 0x6000) != 0x2000;
}
static inline lfsr_tag_t lfsr_tag_next(lfsr_tag_t tag) {
return tag + 0x1;
}
static inline uint8_t lfsr_tag_filetype(lfsr_tag_t tag) {
return tag - LFSR_TAG_REG;
}
static inline bool lfsr_tag_isinternal(lfsr_tag_t tag) {
// bit 4 is currently unused, use for internal use for now
// (may change in the future)
return tag & 0x0800;
}
static inline lfsr_tag_t lfsr_tag_setdelta(lfsr_tag_t tag) {
return tag & ~0x0800;
}
// lfsr_rbyd_append diverged specific flags
static inline bool lfsr_tag_hasdiverged(lfsr_tag_t tag) {
return tag & 0x2000;
}
static inline bool lfsr_tag_isdivergedupper(lfsr_tag_t tag) {
return tag & 0x1000;
}
static inline bool lfsr_tag_isdivergedlower(lfsr_tag_t tag) {
return !lfsr_tag_isdivergedupper(tag);
}
static inline lfsr_tag_t lfsr_tag_setdivergedlower(lfsr_tag_t tag) {
return tag | 0x2000;
}
static inline lfsr_tag_t lfsr_tag_setdivergedupper(lfsr_tag_t tag) {
return tag | 0x3000;
}
// alt operations
static inline bool lfsr_tag_isblack(lfsr_tag_t tag) {
return !(tag & 0x1000);
}
static inline bool lfsr_tag_isred(lfsr_tag_t tag) {
return tag & 0x1000;
}
static inline lfsr_tag_t lfsr_tag_setblack(lfsr_tag_t tag) {
return tag & ~0x1000;
}
static inline lfsr_tag_t lfsr_tag_setred(lfsr_tag_t tag) {
return tag | 0x1000;
}
static inline bool lfsr_tag_isle(lfsr_tag_t tag) {
return !(tag & 0x2000);
}
static inline bool lfsr_tag_isgt(lfsr_tag_t tag) {
return tag & 0x2000;
}
static inline lfsr_tag_t lfsr_tag_isparallel(lfsr_tag_t a, lfsr_tag_t b) {
return (a & 0x2000) == (b & 0x2000);
}
static inline lfsr_tag_t lfsr_tag_key(lfsr_tag_t tag) {
return tag & 0x0fff;
}
static inline bool lfsr_tag_follow(lfsr_tag_t alt, lfs_size_t weight,
lfs_ssize_t lower, lfs_ssize_t upper,
lfs_ssize_t id, lfsr_tag_t tag) {
if (lfsr_tag_isgt(alt)) {
return id > upper - (lfs_ssize_t)weight - 1
|| (id == upper - (lfs_ssize_t)weight - 1
&& lfsr_tag_key(tag) > lfsr_tag_key(alt));
} else {
return id < lower + (lfs_ssize_t)weight
|| (id == lower + (lfs_ssize_t)weight
&& lfsr_tag_key(tag) <= lfsr_tag_key(alt));
}
}
static inline bool lfsr_tag_follow2(
lfsr_tag_t alt, lfs_size_t weight,
lfsr_tag_t alt2, lfs_size_t weight2,
lfs_ssize_t lower, lfs_ssize_t upper,
lfs_ssize_t id, lfsr_tag_t tag) {
if (lfsr_tag_isred(alt2) && lfsr_tag_isparallel(alt, alt2)) {
weight += weight2;
}
return lfsr_tag_follow(alt, weight, lower, upper, id, tag);
}
static inline bool lfsr_tag_prune2(
lfsr_tag_t alt, lfs_ssize_t weight,
lfsr_tag_t alt2, lfs_ssize_t weight2,
lfs_ssize_t lower_id, lfs_ssize_t upper_id,
lfsr_tag_t lower_tag, lfsr_tag_t upper_tag) {
if (lfsr_tag_isgt(alt)) {
return lfsr_tag_follow2(
alt, weight,
alt2, weight2,
lower_id, upper_id,
lower_id, lower_tag);
} else {
return lfsr_tag_follow2(
alt, weight,
alt2, weight2,
lower_id, upper_id,
upper_id-1, upper_tag-0x1);
}
}
static inline void lfsr_tag_flip(lfsr_tag_t *alt, lfs_size_t *weight,
lfs_ssize_t lower, lfs_ssize_t upper) {
*alt = *alt ^ 0x2000;
*weight = (upper-lower) - *weight - 1;
}
static inline void lfsr_tag_flip2(lfsr_tag_t *alt, lfs_size_t *weight,
lfsr_tag_t alt2, lfs_size_t weight2,
lfs_ssize_t lower, lfs_ssize_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, lfs_size_t weight,
lfs_ssize_t *lower_id, lfs_ssize_t *upper_id,
lfsr_tag_t *lower_tag, lfsr_tag_t *upper_tag) {
if (lfsr_tag_isgt(alt)) {
*upper_id -= weight;
if (upper_tag) {
*upper_tag = alt + 0x1;
}
} else {
*lower_id += weight;
if (lower_tag) {
*lower_tag = alt + 0x1;
}
}
}
static inline void lfsr_tag_trim2(
lfsr_tag_t alt, lfs_size_t weight,
lfsr_tag_t alt2, lfs_size_t weight2,
lfs_ssize_t *lower_id, lfs_ssize_t *upper_id,
lfsr_tag_t *lower_tag, lfsr_tag_t *upper_tag) {
if (lfsr_tag_isred(alt2)) {
lfsr_tag_trim(alt2, weight2, lower_id, upper_id, lower_tag, upper_tag);
}
lfsr_tag_trim(alt, weight, lower_id, upper_id, 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 id/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_off_t off, lfs_size_t hint,
lfsr_tag_t *tag_, lfs_size_t *weight_, lfs_size_t *size_,
uint32_t *csum_) {
// read the largest possible tag size
lfs_size_t tsize = lfs_min32(LFSR_TAG_DSIZE, lfs->cfg->block_size-off);
uint8_t buf[LFSR_TAG_DSIZE];
int err = lfsr_bd_read(lfs, block, off, hint, &buf, tsize);
if (err) {
return err;
}
if (tsize < 2) {
return LFS_ERR_CORRUPT;
}
uint16_t tag = ((lfsr_tag_t)buf[0] << 8) | ((lfsr_tag_t)buf[1] << 0);
ssize_t d = 2;
if (csum_) {
// 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(*csum_) & 1)) {
return LFS_ERR_INVAL;
}
}
lfs_size_t weight;
lfs_ssize_t d_ = lfs_fromleb128(&weight, &buf[d], tsize-d);
if (d_ < 0) {
return d_;
}
d += d_;
if (weight > 0x7fffffff) {
return LFS_ERR_CORRUPT;
}
lfs_size_t size;
d_ = lfs_fromleb128(&size, &buf[d], tsize-d);
if (d_ < 0) {
return d_;
}
d += d_;
if (size > 0x7fffffff) {
return LFS_ERR_CORRUPT;
}
// optionally crc
if (csum_) {
*csum_ = lfs_crc32c(*csum_, buf, d);
}
// save what we found, note we make a few tweaks on-disk => in-device
// - clear the valid bit from tag, we checked this earlier
// - adjust id so reserved id is -1, so we don't have mixed zero/one indexed
//
*tag_ = tag & 0x7fff;
*weight_ = weight;
*size_ = size;
return d;
}
static lfs_ssize_t lfsr_bd_progtag(lfs_t *lfs,
lfs_block_t block, lfs_off_t off,
lfsr_tag_t tag, lfs_size_t weight, lfs_size_t size,
uint32_t *csum_) {
// check for underflow issues
LFS_ASSERT(weight < 0x80000000);
LFS_ASSERT(size < 0x80000000);
// make sure to include the parity of the current crc
tag |= (lfs_popc(*csum_) & 1) << 15;
// encode into a be16 and pair of leb128s
uint8_t buf[LFSR_TAG_DSIZE];
buf[0] = (uint8_t)(tag >> 8);
buf[1] = (uint8_t)(tag >> 0);
lfs_size_t d = 2;
ssize_t d_ = lfs_toleb128(weight, &buf[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfs_toleb128(size, &buf[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
int err = lfsr_bd_prog(lfs, block, off, &buf, d, csum_);
if (err) {
return err;
}
return d;
}
/// lfsr_data_t stuff ///
// either an on-disk or in-device data pointer
typedef union lfsr_data {
// sign(size)=0 => in-device
// sign(size)=1 => on-disk
lfs_size_t size;
struct {
lfs_size_t size;
const uint8_t *buffer;
lfs_ssize_t did;
} buf;
struct {
lfs_size_t size;
lfs_block_t block;
lfs_off_t off;
} disk;
} lfsr_data_t;
#define LFSR_DATA_NULL LFSR_DATA_BUF(NULL, 0)
#define LFSR_DATA_BUF(_buffer, _size) \
((lfsr_data_t){.buf={ \
.size=_size, \
.buffer=(const void*)(_buffer), \
.did=-1}})
#define LFSR_DATA_NAME(_did, _buffer, _size) \
((lfsr_data_t){.buf={ \
/* note this find the effective leb128 size */ \
.size=_size + (lfs_nlog2((_did)+1)+7-1)/7, \
.buffer=(const void*)(_buffer), \
.did=_did}})
#define LFSR_DATA_LEB128(_did) \
((lfsr_data_t){.buf={ \
/* note this find the effective leb128 size */ \
.size=(lfs_nlog2((_did)+1)+7-1)/7, \
.buffer=NULL, \
.did=_did}})
#define LFSR_DATA_DISK(_block, _off, _size) \
((lfsr_data_t){.disk={ \
.size=(0x80000000 | (_size)), \
.block=_block, \
.off=_off}})
static inline bool lfsr_data_ondisk(lfsr_data_t data) {
return data.size & 0x80000000;
}
static inline lfs_size_t lfsr_data_size(lfsr_data_t data) {
return data.size & 0x7fffffff;
}
static inline lfs_size_t lfsr_data_setondisk(lfs_size_t size) {
return size | 0x80000000;
}
// data<->bd interactions
static lfs_ssize_t lfsr_data_read(lfs_t *lfs, lfsr_data_t data,
lfs_off_t off, void *buffer, lfs_size_t size) {
// limit our off/size to data range
lfs_off_t off_ = lfs_min32(off, lfsr_data_size(data));
lfs_size_t hint_ = lfsr_data_size(data)-off_;
lfs_size_t size_ = lfs_min32(size, hint_);
if (lfsr_data_ondisk(data)) {
int err = lfsr_bd_read(lfs, data.disk.block, data.disk.off+off_,
// note our hint includes the full data range
hint_,
buffer, size_);
if (err) {
return err;
}
} else {
memcpy(buffer, data.buf.buffer+off_, size_);
}
return size_;
}
static lfs_ssize_t lfsr_data_readle32(lfs_t *lfs, lfsr_data_t data,
lfs_off_t off, uint32_t *word) {
lfs_ssize_t d = lfsr_data_read(lfs, data, off, word, sizeof(uint32_t));
if (d < 0) {
return d;
}
// truncated?
if ((lfs_size_t)d < sizeof(uint32_t)) {
return LFS_ERR_CORRUPT;
}
*word = lfs_fromle32_(word);
return sizeof(uint32_t);
}
static lfs_ssize_t lfsr_data_readleb128(lfs_t *lfs, lfsr_data_t data,
lfs_off_t off, uint32_t *word) {
// 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, off, buf, 5);
if (d < 0) {
return d;
}
return lfs_fromleb128(word, buf, d);
}
static lfs_scmp_t lfsr_data_cmp(lfs_t *lfs, lfsr_data_t data,
lfs_off_t off, const void *buffer, lfs_size_t size) {
// limit our off/size to data range
lfs_off_t off_ = lfs_min32(off, lfsr_data_size(data));
lfs_size_t hint_ = lfsr_data_size(data)-off_;
// compare our data
if (lfsr_data_ondisk(data)) {
int cmp = lfsr_bd_cmp(lfs, data.disk.block, data.disk.off+off_, 0,
buffer, lfs_min32(hint_, size));
if (cmp != LFS_CMP_EQ) {
return cmp;
}
} else {
int cmp = memcmp(data.buf.buffer+off_, buffer, size);
if (cmp < 0) {
return LFS_CMP_LT;
} else if (cmp > 0) {
return LFS_CMP_GT;
}
}
// if data is equal, check for size mismatch
if (hint_ < size) {
return LFS_CMP_LT;
} else if (hint_ > size) {
return LFS_CMP_GT;
} else {
return LFS_CMP_EQ;
}
}
static lfs_scmp_t lfsr_data_namecmp(lfs_t *lfs, lfsr_data_t data,
lfs_off_t off, lfs_size_t did, const char *name, lfs_size_t name_size) {
// first compare the did
lfs_size_t did_;
lfs_ssize_t d = lfsr_data_readleb128(lfs, data, off, &did_);
if (d < 0) {
return d;
}
if (did_ < did) {
return LFS_CMP_LT;
} else if (did_ > did) {
return LFS_CMP_GT;
}
// next compare the actual name
return lfsr_data_cmp(lfs, data, off+d, name, name_size);
}
static int lfsr_bd_progdata(lfs_t *lfs,
lfs_block_t block, lfs_off_t off,
lfsr_data_t data,
uint32_t *csum_) {
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.disk.block, data.disk.off+i,
lfsr_data_size(data)-i,
&dat, 1);
if (err) {
return err;
}
err = lfsr_bd_prog(lfs, block, off+i,
&dat, 1,
csum_);
if (err) {
return err;
}
}
} else {
// this is kind of a hack, but when lfsr_data_t is in buffer mode, it
// can also contain a leb128 encoded directory-id prefix
if (data.buf.did != -1) {
// TODO should progleb128 be its own function? rely on caching?
uint8_t buf[5];
lfs_ssize_t d = lfs_toleb128(data.buf.did, buf, 5);
if (d < 0) {
return d;
}
int err = lfsr_bd_prog(lfs, block, off, buf, d, csum_);
if (err) {
return err;
}
off += d;
data.buf.size -= d;
}
int err = lfsr_bd_prog(lfs, block, off,
data.buf.buffer, lfsr_data_size(data),
csum_);
if (err) {
return err;
}
}
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 {
lfs_ssize_t id;
lfsr_tag_t tag;
lfs_ssize_t delta;
union {
// data, either on-disk or in-device
lfsr_data_t data;
// a move of all attrs from an mdir entry
const lfsr_mdir_t *mdir;
// a grm update, note this is mutable! we may update
// the grm during mdir commits
lfsr_grm_t *grm;
} d;
} lfsr_attr_t;
#define LFSR_ATTR_DATA_(_id, _tag, _delta, _data) \
((const lfsr_attr_t){_id, _tag, _delta, {.data=_data}})
#define LFSR_ATTR_DATA(_id, _type, _delta, _data) \
LFSR_ATTR_DATA_(_id, LFSR_TAG_##_type, _delta, _data)
#define LFSR_ATTR_MOVE_(_new_id, _type, _delta, _mdir) \
((const lfsr_attr_t){_new_id, _type, _delta, {.mdir=_mdir}})
#define LFSR_ATTR_MOVE(_new_id, _type, _delta, _mdir) \
LFSR_ATTR_MOVE_(_new_id, LFSR_TAG_##_type, _delta, _mdir)
#define LFSR_ATTR_GRM_(_new_id, _type, _delta, _grm) \
((const lfsr_attr_t){_new_id, _type, _delta, {.grm=_grm}})
#define LFSR_ATTR_GRM(_new_id, _type, _delta, _grm) \
LFSR_ATTR_GRM_(_new_id, LFSR_TAG_##_type, _delta, _grm)
#define LFSR_ATTR_NAME_(_id, _tag, _delta, _did, _buffer, _size) \
LFSR_ATTR_DATA_(_id, _tag, _delta, LFSR_DATA_NAME(_did, _buffer, _size))
#define LFSR_ATTR_NAME(_id, _type, _delta, _did, _buffer, _size) \
LFSR_ATTR_NAME_(_id, LFSR_TAG_##_type, _delta, _did, _buffer, _size)
#define LFSR_ATTR_LEB128_(_id, _tag, _delta, _did) \
LFSR_ATTR_DATA_(_id, _tag, _delta, LFSR_DATA_LEB128(_did))
#define LFSR_ATTR_LEB128(_id, _type, _delta, _did) \
LFSR_ATTR_LEB128_(_id, LFSR_TAG_##_type, _delta, _did)
#define LFSR_ATTR_(_id, _tag, _delta, _buffer, _size) \
LFSR_ATTR_DATA_(_id, _tag, _delta, LFSR_DATA_BUF(_buffer, _size))
#define LFSR_ATTR(_id, _type, _delta, _buffer, _size) \
LFSR_ATTR_(_id, LFSR_TAG_##_type, _delta, _buffer, _size)
#define LFSR_ATTR_DISK_(_id, _tag, _delta, _block, _off, _size) \
LFSR_ATTR_DATA_(_id, _tag, _delta, LFSR_DATA_DISK(_block, _off, _size))
#define LFSR_ATTR_DISK(_id, _type, _delta, _block, _off, _size) \
LFSR_ATTR_DISK_(_id, LFSR_TAG_##_type, _delta, _block, _off, _size)
#define LFSR_ATTR_NOOP LFSR_ATTR(-1, UNR, 0, NULL, 0)
#define LFSR_ATTRS(...) \
(const lfsr_attr_t[]){__VA_ARGS__}, \
sizeof((const lfsr_attr_t[]){__VA_ARGS__}) / sizeof(lfsr_attr_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
// fcrc on-disk encoding
typedef struct lfsr_fcrc {
uint32_t crc;
lfs_size_t size;
} lfsr_fcrc_t;
// 1 leb128 + 1 crc32c => 9 bytes (worst case)
#define LFSR_FCRC_DSIZE (5+4)
static lfs_ssize_t lfsr_fcrc_todisk(lfs_t *lfs, const lfsr_fcrc_t *fcrc,
uint8_t buffer[static LFSR_FCRC_DSIZE]) {
(void)lfs;
lfs_ssize_t d = 0;
lfs_tole32_(fcrc->crc, &buffer[d]);
d += 4;
lfs_ssize_t d_ = lfs_toleb128(fcrc->size, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
return d;
}
static lfs_ssize_t lfsr_fcrc_fromdisk(lfs_t *lfs, lfsr_fcrc_t *fcrc,
lfsr_data_t data) {
lfs_ssize_t d = 0;
lfs_ssize_t d_ = lfsr_data_readle32(lfs, data, d, &fcrc->crc);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfsr_data_readleb128(lfs, data, d, &fcrc->size);
if (d_ < 0) {
return d_;
}
d += d_;
return d;
}
//// 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;
//}
/// Metadata-id things ///
#define LFSR_MID(_bid, _rid) ((lfsr_mid_t){.bid=_bid, .rid=_rid})
static inline int lfsr_mid_cmp(lfsr_mid_t a, lfsr_mid_t b) {
union { lfsr_mid_t mid; lfs_ssize_t w; } a_u = {.mid=a};
union { lfsr_mid_t mid; lfs_ssize_t w; } b_u = {.mid=b};
return a_u.w - b_u.w;
}
// we use the root's bookmark at 0.0 to represent root
static inline bool lfsr_mid_isroot(lfsr_mid_t mid) {
return lfsr_mid_cmp(mid, LFSR_MID(0, 0)) == 0;
}
/// 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) {
(void)size;
// expect xor to fit
LFS_ASSERT(lfsr_data_size(xor) <= size);
// 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 < lfsr_data_size(xor); i++) {
uint8_t x;
lfs_ssize_t d = lfsr_data_read(lfs, xor, i, &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->mids[0].rid != -1;
}
static inline uint8_t lfsr_grm_count(const lfsr_grm_t *grm) {
return (grm->mids[0].rid != -1) + (grm->mids[1].rid != -1);
}
static inline void lfsr_grm_pushrm(lfsr_grm_t *grm, lfsr_mid_t mid) {
LFS_ASSERT(grm->mids[1].rid == -1);
grm->mids[1] = grm->mids[0];
grm->mids[0] = mid;
}
static inline void lfsr_grm_poprm(lfsr_grm_t *grm) {
grm->mids[0] = grm->mids[1];
grm->mids[1] = LFSR_MID(-1, -1);
}
static int lfsr_grm_todisk(lfs_t *lfs, const lfsr_grm_t *grm,
uint8_t buffer[static LFSR_GRM_DSIZE]) {
(void)lfs;
// 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
// encode no-rm as zero-size
uint8_t count = lfsr_grm_count(grm);
lfs_ssize_t d = 0;
buffer[d] = count;
d += 1;
for (uint8_t i = 0; i < count; i++) {
// map mid=-1 (mroot) to mid=0
lfs_ssize_t d_ = lfs_toleb128(
lfs_smax32(grm->mids[i].bid, 0), &buffer[d], 3);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfs_toleb128(grm->mids[i].rid, &buffer[d], 3);
if (d_ < 0) {
return d_;
}
d += d_;
}
return 0;
}
// needed in lfsr_grm_fromdisk
static inline bool lfsr_mtree_isinlined(lfs_t *lfs);
static inline lfs_size_t lfsr_mtree_weight(lfs_t *lfs);
static int lfsr_grm_fromdisk(lfs_t *lfs, lfsr_grm_t *grm,
uint8_t buffer[static LFSR_GRM_DSIZE]) {
// get the count from the first byte
lfs_ssize_t d = 0;
uint8_t count = buffer[0];
d += 1;
// clear first
grm->mids[0] = LFSR_MID(-1, -1);
grm->mids[1] = LFSR_MID(-1, -1);
LFS_ASSERT(count <= 2);
for (uint8_t i = 0; i < count; i++) {
lfs_size_t bid;
lfs_ssize_t d_ = lfs_fromleb128(&bid, &buffer[d], LFSR_GRM_DSIZE-d);
if (d_ < 0) {
return d_;
}
d += d_;
// TODO should these checks be in lfsr_data_readleb128?
LFS_ASSERT(bid <= 0x7fff);
lfs_size_t rid;
d_ = lfs_fromleb128(&rid, &buffer[d], LFSR_GRM_DSIZE-d);
if (d_ < 0) {
return d_;
}
d += d_;
// TODO should these checks be in lfsr_data_readleb128?
LFS_ASSERT(rid < 0x7fff);
// adjust mid if mtree is inlined
LFS_ASSERT(lfsr_mtree_isinlined(lfs) || bid < lfsr_mtree_weight(lfs));
grm->mids[i] = LFSR_MID(
lfs_smin32(bid, lfsr_mtree_weight(lfs)-1),
rid);
}
return 0;
}
static inline bool lfsr_grm_iszero(const uint8_t gdelta[LFSR_GRM_DSIZE]) {
return lfsr_gdelta_iszero(gdelta, LFSR_GRM_DSIZE);
}
static inline lfs_size_t lfsr_grm_size(const uint8_t gdelta[LFSR_GRM_DSIZE]) {
return lfsr_gdelta_size(gdelta, LFSR_GRM_DSIZE);
}
static inline int lfsr_grm_xor(lfs_t *lfs,
uint8_t gdelta[LFSR_GRM_DSIZE],
lfsr_data_t xor) {
return lfsr_gdelta_xor(lfs, gdelta, LFSR_GRM_DSIZE, xor);
}
/// 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_ack(lfs_t *lfs);
// and our main "fix everything before writing" function
static int lfsr_fs_preparemutation(lfs_t *lfs);
static int lfsr_fs_fixgrm(lfs_t *lfs);
/// Red-black-yellow Dhara tree operations ///
// helper functions
static bool lfsr_rbyd_isfetched(const lfsr_rbyd_t *rbyd) {
return !(rbyd->off == 0 && rbyd->trunk > 0);
}
// allocate an rbyd block
static int lfsr_rbyd_alloc(lfs_t *lfs, lfsr_rbyd_t *rbyd) {
*rbyd = (lfsr_rbyd_t){.weight=0, .trunk=0, .off=0, .crc=0};
int err = lfs_alloc(lfs, &rbyd->block);
if (err) {
return err;
}
// TODO should erase be implicit in alloc eventually?
err = lfsr_bd_erase(lfs, rbyd->block);
if (err) {
return err;
}
return 0;
}
static int lfsr_rbyd_fetch(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_block_t block, lfs_size_t trunk) {
// checksum the revision count to get the crc started
uint32_t crc = 0;
int err = lfsr_bd_csum(lfs, block, 0, lfs->cfg->block_size,
sizeof(uint32_t), &crc);
if (err) {
return err;
}
rbyd->block = block;
rbyd->off = 0;
rbyd->trunk = 0;
// temporary state until we validate a crc
lfs_off_t off = sizeof(uint32_t);
lfs_off_t trunk_ = 0;
bool wastrunk = false;
lfs_size_t weight = 0;
lfs_size_t weight_ = 0;
// assume unerased until proven otherwise
lfsr_fcrc_t fcrc;
bool hasfcrc = false;
bool maybeerased = false;
// scan tags, checking valid bits, crcs, etc
while (off < lfs->cfg->block_size && (!trunk || rbyd->off <= trunk)) {
lfsr_tag_t tag;
lfs_size_t w;
lfs_size_t size;
lfs_ssize_t d = lfsr_bd_readtag(lfs,
block, off, lfs->cfg->block_size,
&tag, &w, &size, &crc);
if (d < 0) {
if (d == LFS_ERR_INVAL || d == LFS_ERR_CORRUPT) {
maybeerased = maybeerased && d == LFS_ERR_INVAL;
break;
}
return d;
}
off += d;
// tag goes out of range?
if (!lfsr_tag_isalt(tag) && off + size > lfs->cfg->block_size) {
break;
}
// not an end-of-commit crc
if (!lfsr_tag_isalt(tag) && lfsr_tag_suptype(tag) != LFSR_TAG_CRC) {
// crc the entry, hopefully leaving it in the cache
err = lfsr_bd_csum(lfs, block, off, lfs->cfg->block_size, size,
&crc);
if (err) {
if (err == LFS_ERR_CORRUPT) {
break;
}
return err;
}
// found an fcrc? save for later
if (tag == LFSR_TAG_FCRC) {
uint8_t buf[LFSR_FCRC_DSIZE];
err = lfsr_bd_read(lfs, block, off, lfs->cfg->block_size,
buf, lfs_min32(size, LFSR_FCRC_DSIZE));
if (err) {
if (err == LFS_ERR_CORRUPT) {
break;
}
return err;
}
lfs_ssize_t d = lfsr_fcrc_fromdisk(lfs, &fcrc,
LFSR_DATA_BUF(buf, lfs_min32(size, LFSR_FCRC_DSIZE)));
if (d < 0 && d != LFS_ERR_CORRUPT) {
return d;
}
// ignore malformed fcrcs
hasfcrc = (d != LFS_ERR_CORRUPT);
}
// is an end-of-commit crc
} else if (!lfsr_tag_isalt(tag)) {
uint32_t crc_ = 0;
err = lfsr_bd_read(lfs, block, off, lfs->cfg->block_size,
&crc_, sizeof(uint32_t));
if (err) {
if (err == LFS_ERR_CORRUPT) {
break;
}
return err;
}
crc_ = lfs_fromle32_(&crc_);
if (crc != crc_) {
// uh oh, crcs don't match
break;
}
// 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_crc32c(lfs->seed, &crc, sizeof(uint32_t));
// fcrc appears valid so far
maybeerased = hasfcrc;
hasfcrc = false;
// save what we've found so far
rbyd->off = off + size;
rbyd->crc = crc;
rbyd->trunk = trunk_;
rbyd->weight = weight;
}
// found a trunk of a tree?
if (lfsr_tag_istrunk(tag)
&& (!trunk || trunk >= off-d || wastrunk)) {
// start of trunk?
if (!wastrunk) {
wastrunk = true;
// save trunk entry point
trunk_ = off-d;
// 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 crc
weight_ += w;
// end of trunk?
if (!lfsr_tag_isalt(tag)) {
wastrunk = false;
// update current weight
weight = weight_;
}
}
if (!lfsr_tag_isalt(tag)) {
off += size;
}
}
// no valid commits?
if (!rbyd->trunk) {
return LFS_ERR_CORRUPT;
}
// did we end on a valid commit? we may have an erased block
bool erased = false;
if (maybeerased && rbyd->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_ = 0;
int err = lfsr_bd_csum(lfs, rbyd->block, rbyd->off, 0, fcrc.size,
&fcrc_);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// found beginning of erased part?
erased = (fcrc_ == fcrc.crc);
}
if (!erased) {
rbyd->off = -1;
}
return 0;
}
static int lfsr_rbyd_lookupnext(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t id, lfsr_tag_t tag,
lfs_ssize_t *id_, lfsr_tag_t *tag_, lfs_size_t *weight_,
lfsr_data_t *data_) {
// tag must be valid at this point
LFS_ASSERT(lfsr_tag_isvalid(tag));
// these bits should be clear at this point
LFS_ASSERT(lfsr_tag_mode(tag) == 0x0000);
// make sure we never look up zero tags, the way we create
// unreachable tags has a hole here
tag = lfs_max16(tag, 0x1);
// keep track of bounds as we descend down the tree
lfs_off_t branch = rbyd->trunk;
lfs_ssize_t lower = -1;
lfs_ssize_t upper = rbyd->weight;
// no trunk yet?
if (!branch) {
return LFS_ERR_NOENT;
}
// descend down tree
while (true) {
lfsr_tag_t alt;
lfs_size_t weight;
lfs_off_t jump;
lfs_ssize_t d = lfsr_bd_readtag(lfs,
rbyd->block, 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, id, 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 id
lfs_ssize_t id__ = upper-1;
lfsr_tag_t tag__ = alt;
LFS_ASSERT(lfsr_tag_mode(tag__) == 0x0000);
// not what we're looking for?
if (!tag__
|| id__ < id
|| (id__ == id && tag__ < tag)) {
return LFS_ERR_NOENT;
}
// save what we found
// TODO how many of these need to be conditional?
if (id_) {
*id_ = id__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = id__ - lower;
}
if (data_) {
*data_ = LFSR_DATA_DISK(rbyd->block, branch + d, jump);
}
return 0;
}
}
}
static int lfsr_rbyd_lookup(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t id, lfsr_tag_t tag,
lfsr_tag_t *tag_, lfsr_data_t *data_) {
lfs_ssize_t id_;
lfsr_tag_t tag__;
int err = lfsr_rbyd_lookupnext(lfs, rbyd, id, lfsr_tag_clearwide(tag),
&id_, &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
//
// we accept either exact matches or suptype matches depending on the
// wide bit
if (id_ != id
|| (lfsr_tag_iswide(tag)
? lfsr_tag_suptype(tag__) != lfsr_tag_clearwide(tag)
: tag__ != tag)) {
return LFS_ERR_NOENT;
}
if (tag_) {
*tag_ = tag__;
}
return 0;
}
// TODO still need this?
// TODO move this into the tests?
static lfs_ssize_t lfsr_rbyd_get(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t id, lfsr_tag_t tag, void *buffer, lfs_size_t size) {
lfsr_data_t data;
int err = lfsr_rbyd_lookup(lfs, rbyd, id, tag, NULL, &data);
if (err) {
return err;
}
return lfsr_data_read(lfs, data, 0, buffer, size);
}
// 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->off == 0);
// revision count stored as le32, we don't use a leb128 encoding as we
// intentionally allow the revision count to overflow
uint8_t buf[sizeof(uint32_t)];
lfs_tole32_(rev, &buf);
int err = lfsr_bd_prog(lfs, rbyd->block, rbyd->off,
&buf, sizeof(uint32_t), &rbyd->crc);
if (err) {
goto failed;
}
rbyd->off += sizeof(uint32_t);
return 0;
failed:
// if we fail mark the rbyd as unerased and release the pcache
lfs_cache_zero(lfs, &lfs->pcache);
rbyd->off = -1;
return err;
}
// helper functions for managing the 3-element fifo used in lfsr_rbyd_append
static int lfsr_rbyd_p_flush(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfsr_tag_t p_alts[static 3],
lfs_size_t p_weights[static 3],
lfs_off_t p_jumps[static 3],
unsigned count) {
// write out some number of alt pointers in our queue
for (unsigned 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];
lfs_size_t weight = p_weights[3-1-i];
lfs_off_t jump = rbyd->off - p_jumps[3-1-i];
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->block, rbyd->off,
alt, weight, jump,
&rbyd->crc);
if (d < 0) {
return d;
}
rbyd->off += d;
}
}
return 0;
}
static inline int lfsr_rbyd_p_push(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfsr_tag_t p_alts[static 3],
lfs_size_t p_weights[static 3],
lfs_off_t p_jumps[static 3],
lfsr_tag_t alt, lfs_ssize_t weight, lfs_off_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(lfs_size_t));
memmove(p_jumps+1, p_jumps, 2*sizeof(lfs_off_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],
lfs_size_t p_weights[static 3],
lfs_off_t p_jumps[static 3]) {
memmove(p_alts, p_alts+1, 2*sizeof(lfsr_tag_t));
memmove(p_weights, p_weights+1, 2*sizeof(lfs_size_t));
memmove(p_jumps, p_jumps+1, 2*sizeof(lfs_off_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],
lfs_size_t p_weights[static 3],
lfs_off_t p_jumps[static 3]) {
// propagate a red edge upwards
p_alts[0] = lfsr_tag_setblack(p_alts[0]);
if (p_alts[1]) {
p_alts[1] = lfsr_tag_setred(p_alts[1]);
// 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];
lfs_size_t weight_ = p_weights[1];
lfs_off_t jump_ = p_jumps[1];
p_alts[1] = lfsr_tag_setred(p_alts[0]);
p_weights[1] = p_weights[0];
p_jumps[1] = p_jumps[0];
p_alts[0] = lfsr_tag_setblack(alt_);
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];
lfs_size_t weight_ = p_weights[2];
lfs_off_t jump_ = p_jumps[2];
p_alts[2] = lfsr_tag_setred(p_alts[1]);
p_weights[2] = p_weights[1];
p_jumps[2] = p_jumps[1];
p_alts[1] = lfsr_tag_setred(p_alts[0]);
p_weights[1] = p_weights[0];
p_jumps[1] = p_jumps[0];
p_alts[0] = lfsr_tag_setblack(alt_);
p_weights[0] = weight_;
p_jumps[0] = jump_;
} else {
LFS_UNREACHABLE();
}
}
}
}
// core rbyd algorithm
static int lfsr_rbyd_append(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_ssize_t id, lfsr_tag_t tag, lfs_ssize_t delta,
lfsr_data_t data) {
// must fetch before mutating!
LFS_ASSERT(lfsr_rbyd_isfetched(rbyd));
// tag must be valid at this point
LFS_ASSERT(lfsr_tag_isvalid(tag));
LFS_ASSERT(!lfsr_tag_isinternal(tag));
// never write zero tags to disk, use unr if tag contains no data
LFS_ASSERT(tag != 0);
// reserve bit 7 to allow leb128 subtypes in the future
LFS_ASSERT(!(tag & 0x80));
// we can't do anything if we're not erased
int err;
if (rbyd->off >= lfs->cfg->block_size) {
err = LFS_ERR_RANGE;
goto failed;
}
// ignore noops
// TODO is there a better way to represent noops?
if (lfsr_tag_cleargrow(tag) == LFSR_TAG_UNR && delta == 0) {
return 0;
}
// make sure every rbyd starts with a revision count
if (rbyd->off == 0) {
err = lfsr_rbyd_appendrev(lfs, rbyd, 0);
if (err) {
goto failed;
}
}
// 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
lfs_ssize_t id_;
lfs_ssize_t other_id_;
lfsr_tag_t tag_;
lfsr_tag_t other_tag_;
if (delta != 0 && !lfsr_tag_isgrow(tag)) {
LFS_ASSERT(!lfsr_tag_iswide(tag));
if (delta > 0) {
LFS_ASSERT(id <= (lfs_ssize_t)rbyd->weight);
// it's a bit ugly, but adjusting the id here makes the following
// logic work out more consistently
id -= 1;
id_ = id + 1;
other_id_ = id + 1;
} else {
LFS_ASSERT(id < (lfs_ssize_t)rbyd->weight);
// it's a bit ugly, but adjusting the id here makes the following
// logic work out more consistently
id += 1;
id_ = id - lfs_smax32(-delta, 0);
other_id_ = id;
}
// note these tags MUST NOT be zero, due to unreachable tag holes
tag_ = 0x1;
other_tag_ = tag_;
} else {
LFS_ASSERT(id < (lfs_ssize_t)rbyd->weight);
id_ = id - lfs_smax32(-delta, 0);
other_id_ = id;
// 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_iswide(tag)) {
tag_ = lfsr_tag_suptype(lfsr_tag_key(tag));
other_tag_ = tag_ + 0x100;
} else if (lfsr_tag_isrm(tag)) {
tag_ = lfsr_tag_key(tag);
other_tag_ = tag_ + 0x1;
} else {
tag_ = lfsr_tag_key(tag);
other_tag_ = tag_;
}
}
// mark as invalid until found
tag_ = lfsr_tag_setinvalid(tag_);
other_tag_ = lfsr_tag_setinvalid(other_tag_);
// 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_off_t branch = rbyd->trunk;
lfs_ssize_t lower_id = -1;
lfs_ssize_t upper_id = 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_off_t other_branch = 0;
lfs_ssize_t other_lower_id = 0;
lfs_ssize_t other_upper_id = 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 >= -(lfs_ssize_t)rbyd->weight);
rbyd->weight += delta;
// assume we'll update our trunk
rbyd->trunk = rbyd->off;
// 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};
lfs_size_t p_weights[3] = {0, 0, 0};
lfs_off_t p_jumps[3] = {0, 0, 0};
lfs_off_t graft = 0;
// descend down tree, building alt pointers
while (true) {
// read the alt pointer
lfsr_tag_t alt;
lfs_size_t weight;
lfs_off_t jump;
lfs_ssize_t d = lfsr_bd_readtag(lfs,
rbyd->block, branch, 0,
&alt, &weight, &jump, NULL);
if (d < 0) {
err = d;
goto failed;
}
// found an alt?
if (lfsr_tag_isalt(alt)) {
// make jump absolute
jump = branch - jump;
lfs_off_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_id, upper_id,
id_, tag_)
!= lfsr_tag_follow2(alt, weight,
p_alts[0], p_weights[0],
lower_id, upper_id,
other_id_, other_tag_)) {
// first take care of any lingering red alts
if (lfsr_tag_isred(p_alts[0])) {
alt = lfsr_tag_setblack(p_alts[0]);
weight = p_weights[0];
jump = p_jumps[0];
branch_ = branch;
lfsr_rbyd_p_pop(p_alts, p_weights, p_jumps);
} else {
tag_ = lfsr_tag_setdivergedlower(tag_);
other_tag_ = lfsr_tag_setdivergedupper(other_tag_);
other_branch = branch;
other_lower_id = lower_id;
other_upper_id = upper_id;
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_setblack(alt);
}
// 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_id, upper_id,
lower_tag, upper_tag)) {
if (lfsr_tag_isred(p_alts[0])) {
alt = lfsr_tag_setblack(p_alts[0]);
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_id, upper_id,
id_, tag_)) {
lfsr_tag_flip2(&alt, &weight,
p_alts[0], p_weights[0],
lower_id, upper_id);
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_setblack(alt);
lfsr_tag_trim(
p_alts[0], p_weights[0],
&lower_id, &upper_id,
&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_id, &upper_id,
&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_id, upper_id,
id_, tag_)) {
lfsr_tag_flip2(&alt, &weight,
p_alts[0], p_weights[0],
lower_id, upper_id);
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_id, upper_id,
id_, tag_)) {
lfs_swap16(&p_alts[0], &alt);
lfs_swap32(&p_weights[0], &weight);
lfs_swap32(&p_jumps[0], &jump);
p_alts[0] = lfsr_tag_setred(p_alts[0]);
alt = lfsr_tag_setblack(alt);
lfsr_tag_flip2(&alt, &weight,
p_alts[0], p_weights[0],
lower_id, upper_id);
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_id, &upper_id,
&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
err = lfsr_rbyd_p_push(lfs, rbyd,
p_alts, p_weights, p_jumps,
alt, weight, jump);
if (err) {
goto failed;
}
// found end of tree?
} else {
// update the found tag/id
//
// note we:
// - clear valid bit, marking the tag as found
// - preserve diverged state
LFS_ASSERT(lfsr_tag_mode(alt) == 0x0000);
tag_ = lfsr_tag_setvalid(lfsr_tag_mode(tag_) | alt);
id_ = upper_id-1;
// done?
if (!lfsr_tag_hasdiverged(tag_) || lfsr_tag_isvalid(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(&id_, &other_id_);
lfs_swap32(&branch, &other_branch);
lfs_sswap32(&lower_id, &other_lower_id);
lfs_sswap32(&upper_id, &other_upper_id);
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_isvalid(tag_));
LFS_ASSERT(!lfsr_tag_hasdiverged(tag_) || lfsr_tag_isvalid(other_tag_));
if (lfsr_tag_hasdiverged(tag_)) {
if (lfsr_tag_isdivergedlower(tag_)) {
// finished on lower path
tag_ = other_tag_;
id_ = other_id_;
branch = other_branch;
upper_id = other_upper_id;
} else {
// finished on upper path
lower_id = other_lower_id;
}
}
// 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;
lfs_size_t weight = 0;
if (lfsr_tag_key(tag_)
&& (id_ < id-lfs_smax32(-delta, 0)
|| (id_ == id-lfs_smax32(-delta, 0)
&& ((delta > 0 && !lfsr_tag_isgrow(tag))
|| (lfsr_tag_iswide(tag)
? lfsr_tag_suptype(lfsr_tag_key(tag_))
< lfsr_tag_suptype(lfsr_tag_key(tag))
: lfsr_tag_key(tag_)
< lfsr_tag_key(tag)))))) {
if (lfsr_tag_isrm(tag)) {
// if removed, make our tag unreachable
alt = LFSR_TAG_ALTGT(false, 0);
weight = upper_id - lower_id - 1 + delta;
upper_id -= weight;
} else {
// split less than
alt = LFSR_TAG_ALTLE(
!lfsr_tag_hasdiverged(tag_),
lfsr_tag_key(tag_));
weight = id_ - lower_id;
lower_id += weight;
}
} else if (lfsr_tag_key(tag_)
&& (id_ > id
|| (id_ == id
&& ((delta > 0 && !lfsr_tag_isgrow(tag))
|| (lfsr_tag_iswide(tag)
? lfsr_tag_suptype(lfsr_tag_key(tag_))
> lfsr_tag_suptype(lfsr_tag_key(tag))
: lfsr_tag_key(tag_)
> lfsr_tag_key(tag)))))) {
if (lfsr_tag_isrm(tag)) {
// if removed, make our tag unreachable
alt = LFSR_TAG_ALTGT(false, 0);
weight = upper_id - lower_id - 1 + delta;
upper_id -= weight;
} else {
// split greater than
alt = LFSR_TAG_ALTGT(
!lfsr_tag_hasdiverged(tag_),
lfsr_tag_key(tag));
weight = upper_id - id - 1;
upper_id -= weight;
}
}
if (alt) {
err = lfsr_rbyd_p_push(lfs, rbyd,
p_alts, p_weights, p_jumps,
alt, weight, branch);
if (err) {
goto failed;
}
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
err = lfsr_rbyd_p_flush(lfs, rbyd,
p_alts, p_weights, p_jumps, 3);
if (err) {
goto failed;
}
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->block, rbyd->off,
// rm => null, otherwise strip off control bits
(lfsr_tag_isrm(tag) ? LFSR_TAG_NULL : lfsr_tag_key(tag)),
upper_id - lower_id - 1 + delta,
lfsr_data_size(data),
&rbyd->crc);
if (d < 0) {
err = d;
goto failed;
}
rbyd->off += d;
// don't forget the data!
err = lfsr_bd_progdata(lfs, rbyd->block, rbyd->off, data,
&rbyd->crc);
if (err) {
goto failed;
}
rbyd->off += lfsr_data_size(data);
return 0;
failed:;
// if we fail mark the rbyd as unerased and release the pcache
lfs_cache_zero(lfs, &lfs->pcache);
rbyd->off = -1;
return err;
}
static int lfsr_rbyd_appendall(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_ssize_t start_id, lfs_ssize_t end_id,
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++) {
// this is a bit of a hack, but ignore any gstate tags here,
// these need to be handled specially by upper-layers
if (lfsr_tag_suptype(attrs[i].tag) == LFSR_TAG_GSTATE) {
continue;
}
// don't write tags outside of the requested range
if (attrs[i].id >= start_id && (end_id < 0 || attrs[i].id < end_id)) {
// this is a bit of a hack, but ignore any gstate tags here,
// these need to be handled specially by upper-layers
if (lfsr_tag_suptype(attrs[i].tag) == LFSR_TAG_GSTATE) {
// do nothing
// move tags copy over any tags associated with the source's rid
} else if (lfsr_tag_suptype(attrs[i].tag) == LFSR_TAG_MOVE) {
// weighted moves are not supported
LFS_ASSERT(attrs[i].delta == 0);
// skip the name tag, this is always replaced by upper layers
lfsr_tag_t tag = LFSR_TAG_NAME + 0xff;
while (true) {
lfs_ssize_t rid;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs,
&attrs[i].d.mdir->u.r.rbyd,
attrs[i].d.mdir->mid.rid, lfsr_tag_next(tag),
&rid, &tag, NULL, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT
|| rid != attrs[i].d.mdir->mid.rid) {
break;
}
// append the attr
err = lfsr_rbyd_append(lfs, rbyd,
attrs[i].id-lfs_smax32(start_id, 0),
tag, 0, data);
if (err) {
return err;
}
}
// write out normal tags normally
} else {
LFS_ASSERT(!lfsr_tag_isinternal(attrs[i].tag));
int err = lfsr_rbyd_append(lfs, rbyd,
attrs[i].id-lfs_smax32(start_id, 0),
attrs[i].tag, attrs[i].delta, attrs[i].d.data);
if (err) {
return err;
}
}
}
// we need to make sure we keep start_id/end_id updated with
// weight changes
if (attrs[i].id < start_id) {
start_id += attrs[i].delta;
}
if (attrs[i].id < end_id) {
end_id += attrs[i].delta;
}
}
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->dgrm)) {
// calculate our delta
uint8_t buf[LFSR_GRM_DSIZE];
memset(buf, 0, LFSR_GRM_DSIZE);
lfsr_data_t data;
int err = lfsr_rbyd_lookup(lfs, rbyd, -1, LFSR_TAG_GRM, NULL, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
lfs_ssize_t d = lfsr_data_read(lfs, data, 0, buf, LFSR_GRM_DSIZE);
if (d < 0) {
return d;
}
}
err = lfsr_grm_xor(lfs, buf, LFSR_DATA_BUF(&lfs->dgrm, LFSR_GRM_DSIZE));
if (err) {
return err;
}
// append to our rbyd, note this replaces the original delta
lfs_size_t size = lfsr_grm_size(buf);
err = lfsr_rbyd_append(lfs, rbyd, -1,
// opportunistically remove this tag if delta is all zero
(size == 0 ? LFSR_TAG_RMGRM : LFSR_TAG_GRM), 0,
LFSR_DATA_BUF(buf, size));
if (err) {
return err;
}
}
return 0;
}
static int lfsr_rbyd_compact(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_ssize_t start_id, lfs_ssize_t end_id,
const lfsr_rbyd_t *source) {
#ifndef LFSR_NO_REBALANCE
// must fetch before mutating!
LFS_ASSERT(lfsr_rbyd_isfetched(rbyd));
// we can't do anything if we're not erased
int err;
if (rbyd->off >= lfs->cfg->block_size) {
err = LFS_ERR_RANGE;
goto failed;
}
// make sure every rbyd starts with a revision count
if (rbyd->off == 0) {
err = lfsr_rbyd_appendrev(lfs, rbyd, 0);
if (err) {
goto failed;
}
}
// keep track of the number of trunks and weight in each layer
lfs_size_t layer_trunks = 0;
lfs_size_t layer_w = 0;
// first copy over raw tags, note this doesn't create a tree
lfs_off_t layer_start = rbyd->off;
lfs_ssize_t id = start_id;
lfsr_tag_t tag = 0;
while (true) {
lfs_size_t w;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, source, id, lfsr_tag_next(tag),
&id, &tag, &w, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT || (end_id >= 0 && id >= end_id)) {
break;
}
// TODO is this really the best way to do this?
// this is a bit of a hack, but ignore any gstate tags here,
// these need to be handled specially by upper-layers
if (lfsr_tag_suptype(tag) == LFSR_TAG_GSTATE) {
continue;
}
// write the tag
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->block, rbyd->off,
tag, w, lfsr_data_size(data),
&rbyd->crc);
if (d < 0) {
err = d;
goto failed;
}
rbyd->off += d;
// and the data
err = lfsr_bd_progdata(lfs, rbyd->block, rbyd->off, data,
&rbyd->crc);
if (err) {
goto failed;
}
rbyd->off += lfsr_data_size(data);
// keep track of the layer weight/trunks
layer_trunks += 1;
layer_w += w;
}
lfs_off_t layer_end = rbyd->off;
// connect every other trunk together, building layers of a perfectly
// balanced binary tree upwards until we have a single trunk
while (layer_trunks > 1) {
// keep track of new layer trunks/weight
layer_trunks = 0;
layer_w = 0;
lfs_off_t off = layer_start;
layer_start = rbyd->off;
while (off < layer_end) {
// connect two trunks together with a new binary trunk
for (int i = 0; i < 2 && off < layer_end; i++) {
lfs_off_t trunk_off = off;
lfsr_tag_t trunk_tag = 0;
lfs_size_t trunk_w = 0;
while (true) {
lfsr_tag_t tag;
lfs_size_t w;
lfs_size_t size;
lfs_ssize_t d = lfsr_bd_readtag(lfs, rbyd->block, off,
layer_end-off,
&tag, &w, &size, NULL);
if (d < 0) {
err = d;
goto failed;
}
off += d;
// skip any data
if (!lfsr_tag_isalt(tag)) {
off += size;
}
// keep track of trunk/layer weight, and 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
trunk_w += w;
layer_w += w;
if (tag) {
trunk_tag = tag;
}
// read all tags in the trunk
if (!lfsr_tag_isalt(tag)) {
break;
}
}
// connect with an altle
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->block, rbyd->off,
LFSR_TAG_ALTLE(false, lfsr_tag_key(trunk_tag)),
trunk_w,
rbyd->off - trunk_off,
&rbyd->crc);
if (d < 0) {
err = d;
goto failed;
}
rbyd->off += d;
}
// terminate with a null tag
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->block, rbyd->off,
LFSR_TAG_NULL, 0, 0,
&rbyd->crc);
if (d < 0) {
err = d;
goto failed;
}
rbyd->off += d;
// keep track of the number of trunks
layer_trunks += 1;
}
layer_end = rbyd->off;
}
// done! just need to update our trunk/weight, note we could have
// no trunks after compaction. Leave this to upper layers to take
// care of
if (layer_trunks >= 1) {
rbyd->trunk = layer_start;
}
rbyd->weight = layer_w;
return 0;
failed:;
// if we fail mark the rbyd as unerased and release the pcache
lfs_cache_zero(lfs, &lfs->pcache);
rbyd->off = -1;
return err;
#else
// try to copy over tags
lfs_ssize_t id = start_id;
lfsr_tag_t tag = 0;
while (true) {
lfs_size_t w;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, source, id, lfsr_tag_next(tag),
&id, &tag, &w, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT || (end_id >= 0 && id >= end_id)) {
return 0;
}
// this is a bit of a hack, but ignore any gstate tags here,
// these need to be handled specially by upper-layers
if (lfsr_tag_suptype(tag) == LFSR_TAG_GSTATE) {
continue;
}
// append the attr
err = lfsr_rbyd_append(lfs, rbyd,
id-lfs_smax32(w-1, 0)-lfs_smax32(start_id, 0),
tag, +w, data);
if (err) {
return err;
}
}
#endif
}
static int lfsr_rbyd_commit(lfs_t *lfs, lfsr_rbyd_t *rbyd,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// must fetch before mutating!
LFS_ASSERT(lfsr_rbyd_isfetched(rbyd));
// we can't do anything if we're not erased
int err;
if (rbyd->off >= lfs->cfg->block_size) {
err = LFS_ERR_RANGE;
goto failed;
}
// setup commit state, use a separate rbyd so we have a fallback in
// case of error
lfsr_rbyd_t rbyd_ = *rbyd;
// make sure every rbyd starts with its revision count
if (rbyd_.off == 0) {
err = lfsr_rbyd_appendrev(lfs, &rbyd_, 0);
if (err) {
goto failed;
}
}
// append each tag to the tree
err = lfsr_rbyd_appendall(lfs, &rbyd_, -1, -1,
attrs, attr_count);
if (err) {
goto failed;
}
// align to the next prog unit
//
// this gets a bit complicated as we have two types of crcs:
//
// - 9-word crc with fcrc to check following prog (middle of block)
// - fcrc tag type => 2 byte le16
// - fcrc tag id => 1 byte leb128
// - fcrc tag size => 1 byte leb128 (worst case)
// - fcrc crc => 4 byte le32
// - fcrc size => 5 byte leb128 (worst case)
// - crc tag type => 2 byte le16
// - crc tag id => 1 byte leb128
// - crc tag size => 5 byte leb128 (worst case)
// - crc crc => 4 byte le32
// => 25 bytes total
//
// - 4-word crc with no following prog (end of block)
// - crc tag type => 2 byte le16
// - crc tag id => 1 byte leb128
// - crc tag size => 5 byte leb128 (worst case)
// - crc crc => 4 byte le32
// => 12 bytes total
//
lfs_off_t aligned = lfs_alignup(
rbyd_.off + 2+1+1+4+5 + 2+1+5+4,
lfs->cfg->prog_size);
// space for fcrc?
uint8_t perturb = 0;
if (aligned < 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_.block, aligned, lfs->cfg->prog_size,
&perturb, 1);
if (err && err != LFS_ERR_CORRUPT) {
rbyd->off = -1;
return err;
}
// find the expected fcrc, don't bother avoiding a reread of the
// perturb byte, as it should still be in our cache
lfsr_fcrc_t fcrc = {.crc=0, .size=lfs->cfg->prog_size};
err = lfsr_bd_csum(lfs, rbyd_.block, aligned, lfs->cfg->prog_size,
lfs->cfg->prog_size,
&fcrc.crc);
if (err && err != LFS_ERR_CORRUPT) {
goto failed;
}
uint8_t buf[LFSR_FCRC_DSIZE];
lfs_size_t d = lfsr_fcrc_todisk(lfs, &fcrc, buf);
lfs_ssize_t d_ = lfsr_bd_progtag(lfs, rbyd_.block, rbyd_.off,
LFSR_TAG_FCRC, 0, d,
&rbyd_.crc);
if (d_ < 0) {
err = d_;
goto failed;
}
rbyd_.off += d_;
err = lfsr_bd_prog(lfs, rbyd_.block, rbyd_.off,
buf, d, &rbyd_.crc);
if (err) {
goto failed;
}
rbyd_.off += d;
// at least space for a crc?
} else if (rbyd_.off + 2+1+5+4 <= lfs->cfg->block_size) {
// note this implicitly marks the rbyd as unerased
aligned = lfs->cfg->block_size;
// not even space for a crc? we can't finish the commit
} else {
err = LFS_ERR_RANGE;
goto failed;
}
// build end-of-commit crc
//
// 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 buf[2+1+5+4];
buf[0] = (LFSR_TAG_CRC >> 8) | ((lfs_popc(rbyd_.crc) & 1) << 7);
buf[1] = 0;
buf[2] = 0;
lfs_off_t padding = aligned - (rbyd_.off + 2+1+5);
buf[3] = 0x80 | (0x7f & (padding >> 0));
buf[4] = 0x80 | (0x7f & (padding >> 7));
buf[5] = 0x80 | (0x7f & (padding >> 14));
buf[6] = 0x80 | (0x7f & (padding >> 21));
buf[7] = 0x00 | (0x7f & (padding >> 28));
rbyd_.crc = lfs_crc32c(rbyd_.crc, 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 crc tags just for this purpose
if ((lfs_popc(rbyd_.crc) & 1) == (perturb >> 7)) {
buf[1] ^= 0x01;
rbyd_.crc ^= 0x68032cc8; // note crc(a ^ b) == crc(a) ^ crc(b)
}
lfs_tole32_(rbyd_.crc, &buf[2+1+5]);
err = lfsr_bd_prog(lfs, rbyd_.block, rbyd_.off, buf, 2+1+5+4, NULL);
if (err) {
goto failed;
}
rbyd_.off += 2+1+5+4;
// flush our caches, finalizing the commit on-disk
err = lfsr_bd_sync(lfs);
if (err) {
goto failed;
}
// succesful commit, check checksum to make sure
uint32_t crc_ = rbyd->crc;
err = lfsr_bd_csum(lfs, rbyd_.block, rbyd->off, 0,
rbyd_.off-4 - rbyd->off,
&crc_);
if (err) {
goto failed;
}
if (rbyd_.crc != crc_) {
// oh no, something went wrong
LFS_ERROR("Rbyd corrupted during commit "
"(block=0x%"PRIx32", 0x%08"PRIx32" != 0x%08"PRIx32")",
rbyd_.block, rbyd_.crc, crc_);
err = LFS_ERR_CORRUPT;
goto failed;
}
// ok, everything is good, save what we've committed
rbyd_.off = aligned;
*rbyd = rbyd_;
return 0;
failed:;
// if we fail mark the rbyd as unerased and release the pcache
lfs_cache_zero(lfs, &lfs->pcache);
rbyd->off = -1;
return err;
}
// the following are mostly btree helpers, but since they operate on rbyds,
// exist in the rbyd namespace
// Calculate the maximum possible disk usage required by this id after
// compaction. This uses a conservative estimate so the actual on-disk cost
// should be smaller.
//
static lfs_ssize_t lfsr_rbyd_estimate(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t id,
lfs_ssize_t *id_, lfs_size_t *weight_) {
lfsr_tag_t tag = 0;
lfs_size_t w = 0;
lfs_size_t dsize = 0;
while (true) {
lfs_ssize_t id__;
lfs_size_t w_;
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, rbyd,
id, lfsr_tag_next(tag),
&id__, &tag, &w_, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT || id__ > id+lfs_smax32(w_-1, 0)) {
break;
}
// keep track of id and weight
id = id__;
w += w_;
// determine the upper-bound of alt pointers, tags, and data
// after compaction
//
// note that with rebalancing during compaction, we know the number
// of inner nodes is the same as the number of tags. Each node has
// two alts and is terminated by a 4-byte null tag.
//
#ifndef LFSR_NO_REBALANCE
dsize += 2*LFSR_TAG_DSIZE + 4
+ LFSR_TAG_DSIZE + lfsr_data_size(data);
#else
// TODO is this the best way to do this?
// If we're not rebalancing, we just don't account for the alts. We
// need to know the total size to know how many alts there are, so
// just leave this up to upper layers
dsize += LFSR_TAG_DSIZE + lfsr_data_size(data);
#endif
}
if (id_) {
*id_ = id;
}
if (weight_) {
*weight_ = w;
}
return dsize;
}
// Calculate the maximum possible disk usage required by this id after
// compaction. This uses a conservative estimate so the actual on-disk cost
// should be smaller.
//
// This also returns a good split_id in case the rbyd needs to be split.
//
// TODO do we need to include commit overhead here?
static lfs_ssize_t lfsr_rbyd_estimateall(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t start_id, lfs_ssize_t end_id,
lfs_size_t *split_id_) {
// calculate dsize by starting from the outside ids and working inwards,
// this naturally gives us a split id
//
// note that we don't include -1 tags yet, -1 tags are always cleaned up
// during a split so they shouldn't affect the split_id
//
lfs_ssize_t lower_id = (start_id < 0 ? 0 : start_id);
lfs_ssize_t upper_id = (end_id < 0
? (lfs_ssize_t)rbyd->weight-1
: end_id-1);
lfs_size_t lower_dsize = 0;
lfs_size_t upper_dsize = 0;
while (lower_id <= upper_id) {
if (lower_dsize <= upper_dsize) {
lfs_size_t w;
lfs_ssize_t dsize = lfsr_rbyd_estimate(lfs, rbyd, lower_id,
NULL, &w);
if (dsize < 0) {
return dsize;
}
lower_id += w;
lower_dsize += dsize;
} else {
lfs_size_t w;
lfs_ssize_t dsize = lfsr_rbyd_estimate(lfs, rbyd, upper_id,
NULL, &w);
if (dsize < 0) {
return dsize;
}
upper_id -= w;
upper_dsize += dsize;
}
}
// include -1 tags in our final dsize
lfs_ssize_t dsize = lfsr_rbyd_estimate(lfs, rbyd, -1, NULL, NULL);
if (dsize < 0) {
return dsize;
}
if (split_id_) {
*split_id_ = lower_id;
}
#ifndef LFSR_NO_REBALANCE
return dsize + lower_dsize + upper_dsize;
#else
// TODO if we are serious about providing a LFSR_NO_REBALANCE option, we
// should probably also do this in lfsr_rbyd_estimate, though that raises
// the question how should lfsr_rbyd_estimate/estimateall interact in that
// case?
//
// If we're not rebalancing, we need to account for the overhead of
// intermediary trunks, which is O(log(n)) per trunk.
//
// Assuming worst case all tags are zero-length, and tags are at minimum
// 4 bytes, the worst case total is 4*(2*log2(dsize/4)) + dsize
dsize = dsize + lower_dsize + upper_dsize;
return 4*(2*lfs_nlog2(dsize/4)) + dsize;
#endif
}
// determine if there are fewer than "cutoff" unique ids in the rbyd,
// this is used to determine if the underlying rbyd is degenerate and can
// be reverted to an inlined btree
//
// note cutoff is expected to be quite small, <= 2, so we should make sure
// to exit our traverse early
static int lfsr_rbyd_isdegenerate(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t cutoff) {
// cutoff=-1 => no cutoff
if (cutoff < 0) {
return false;
}
// count ids until we exceed our cutoff
lfs_ssize_t id = -1;
lfs_size_t count = 0;
while (true) {
int err = lfsr_rbyd_lookupnext(lfs, rbyd, id+1, 0,
&id, NULL, NULL, NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
return true;
}
count += 1;
if (count > (lfs_size_t)cutoff) {
return false;
}
}
}
// 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 id_/weight_ with the best
// matching name if not found
static int lfsr_rbyd_namelookup(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_size_t did, const char *name, lfs_size_t name_size,
lfs_ssize_t *id_, lfsr_tag_t *tag_, lfs_size_t *weight_,
lfsr_data_t *data_) {
// if we have an empty mdir, default to id = -1
if (id_) {
*id_ = -1;
}
if (tag_) {
*tag_ = 0;
}
if (weight_) {
*weight_ = 0;
}
if (data_) {
*data_ = LFSR_DATA_NULL;
}
// binary search for our name
lfs_ssize_t lower = 0;
lfs_ssize_t upper = rbyd->weight;
while (lower < upper) {
lfsr_tag_t tag__;
lfs_ssize_t id__;
lfs_size_t weight__;
lfsr_data_t data__;
int err = lfsr_rbyd_lookupnext(lfs, rbyd,
// lookup ~middle id, note we may end up in the middle
// of a weighted id with this
lower + (upper-1-lower)/2, 0,
&id__, &tag__, &weight__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// if we have no name or a vestigial name, treat this id as always lt
lfs_scmp_t cmp;
if ((tag__ == LFSR_TAG_BRANCH && id__-(weight__-1) == 0)
|| lfsr_tag_suptype(tag__) != LFSR_TAG_NAME) {
cmp = LFS_CMP_LT;
// compare names
} else {
cmp = lfsr_data_namecmp(lfs, data__, 0, did, name, name_size);
if (cmp < 0) {
return cmp;
}
}
// bisect search space
if (lfs_cmp(cmp) > 0) {
upper = id__ - (weight__-1);
} else if (lfs_cmp(cmp) < 0) {
lower = id__ + 1;
// keep track of best-matching id >= our target
if (id_) {
*id_ = id__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
} else {
// found a match?
if (id_) {
*id_ = id__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
return 0;
}
}
// no match, at least update id_/tag_/weight_/data_ with the best
// match so far
return LFS_ERR_NOENT;
}
/// Rbyd b-tree operations ///
// convenience operations
// TODO need null btrees?
#define LFSR_BTREE_NULL ((lfsr_btree_t){.u.b.weight=0x80000000})
static inline bool lfsr_btree_isinlined(const lfsr_btree_t *btree) {
return btree->u.b.weight & 0x80000000;
}
static inline lfs_size_t lfsr_btree_weight(const lfsr_btree_t *btree) {
return btree->u.b.weight & 0x7fffffff;
}
static inline bool lfsr_btree_isnull(const lfsr_btree_t *btree) {
return btree->u.b.weight == 0x80000000;
}
// branch on-disk encoding
// 1 crc32c + 3 leb128 => 19 bytes (worst case)
#define LFSR_BRANCH_DSIZE (4+5+5+5)
static lfs_ssize_t lfsr_branch_todisk(lfs_t *lfs, const lfsr_rbyd_t *branch,
uint8_t buffer[static LFSR_BRANCH_DSIZE]) {
(void)lfs;
lfs_ssize_t d = 0;
lfs_tole32_(branch->crc, &buffer[d]);
d += 4;
lfs_ssize_t d_ = lfs_toleb128(branch->weight, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfs_toleb128(branch->trunk, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfs_toleb128(branch->block, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
return d;
}
static lfs_ssize_t lfsr_branch_fromdisk(lfs_t *lfs, lfsr_rbyd_t *branch,
lfsr_data_t data) {
// setting off to 0 here will trigger asserts if we try to append
// without fetching first
branch->off = 0;
lfs_ssize_t d = 0;
lfs_ssize_t d_ = lfsr_data_readle32(lfs, data, d, &branch->crc);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfsr_data_readleb128(lfs, data, d, &branch->weight);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfsr_data_readleb128(lfs, data, d, &branch->trunk);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfsr_data_readleb128(lfs, data, d, &branch->block);
if (d_ < 0) {
return d_;
}
d += d_;
return d;
}
// btree on-disk encoding
//
// note we leave disambiguating inlined/non-inlined btrees up to the caller
#define LFSR_BTREE_DSIZE ( \
LFSR_BRANCH_DSIZE > LFSR_BTREE_INLINESIZE \
? LFSR_BRANCH_DSIZE \
: LFSR_BTREE_INLINESIZE)
static lfs_ssize_t lfsr_btree_todisk(lfs_t *lfs, const lfsr_btree_t *btree,
lfsr_tag_t btree_tag,
lfsr_tag_t *tag_, uint8_t buffer[static LFSR_BTREE_DSIZE]) {
// emit null btrees as an rm to remove anything on-disk
if (lfsr_btree_isnull(btree)) {
*tag_ = LFSR_TAG_RMWIDESTRUCT;
return 0;
// inlined?
} else if (lfsr_btree_isinlined(btree)) {
*tag_ = lfsr_tag_setwide(btree->u.i.tag);
memcpy(buffer, btree->u.i.buffer, btree->u.i.size);
return btree->u.i.size;
// not inlined
} else {
*tag_ = lfsr_tag_setwide(btree_tag);
return lfsr_branch_todisk(lfs, &btree->u.r.rbyd, buffer);
}
}
// TODO wait we actually need to store the weight on-disk for btrees
static lfs_ssize_t lfsr_btree_fromdisk(lfs_t *lfs, lfsr_btree_t *btree,
lfsr_tag_t btree_tag,
lfsr_tag_t tag, lfs_size_t weight, lfsr_data_t data) {
// inlined?
if (tag != btree_tag) {
// mark as inlined
btree->u.i.weight = 0x80000000 | weight;
btree->u.i.tag = tag;
lfs_ssize_t size = lfsr_data_read(lfs, data, 0,
btree->u.i.buffer, LFSR_BTREE_INLINESIZE);
if (size < 0) {
return size;
}
btree->u.i.size = size;
return size;
// not inlined
} else {
return lfsr_branch_fromdisk(lfs, &btree->u.r.rbyd, data);
}
}
// B-tree operations
static int lfsr_btree_lookupnext_(lfs_t *lfs,
const lfsr_btree_t *btree, lfs_size_t bid,
lfs_size_t *bid_, lfsr_rbyd_t *rbyd_, lfs_ssize_t *rid_,
lfsr_tag_t *tag_, lfs_size_t *weight_, lfsr_data_t *data_) {
// in range?
if (bid >= lfsr_btree_weight(btree)) {
return LFS_ERR_NOENT;
}
// inlined?
if (lfsr_btree_isinlined(btree)) {
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = lfsr_btree_weight(btree)-1;
}
if (tag_) {
*tag_ = btree->u.i.tag;
}
if (weight_) {
*weight_ = lfsr_btree_weight(btree);
}
if (data_) {
*data_ = LFSR_DATA_BUF(btree->u.i.buffer, btree->u.i.size);
}
return 0;
}
// descend down the btree looking for our bid
lfsr_rbyd_t branch = btree->u.r.rbyd;
lfs_ssize_t rid = bid;
while (true) {
// each branch is a pair of optional name + on-disk structure
lfs_ssize_t rid__;
lfsr_tag_t tag__;
// TODO do we really need to fetch weight__ if we get it in our
// btree struct?
// TODO maybe only when validating?
lfs_size_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_lookup(lfs, &branch, rid__, LFSR_TAG_WIDESTRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// found another branch
if (tag__ == LFSR_TAG_BTREE) {
// adjust rid with subtree's weight
rid -= (rid__ - (weight__-1));
// fetch the next branch
lfs_ssize_t d = lfsr_branch_fromdisk(lfs, &branch, data__);
if (d < 0) {
return d;
}
LFS_ASSERT(branch.weight == weight__);
// 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, lfs_size_t bid,
lfs_size_t *bid_, lfsr_tag_t *tag_, lfs_size_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, lfs_size_t bid,
lfsr_tag_t *tag_, lfs_size_t *weight_, lfsr_data_t *data_) {
lfs_size_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 still need this?
// TODO move this into the tests?
static int lfsr_btree_get(lfs_t *lfs,
const lfsr_btree_t *btree, lfs_size_t bid,
lfsr_tag_t *tag_, lfs_size_t *weight_,
void *buffer, lfs_size_t size) {
lfsr_data_t data;
int err = lfsr_btree_lookup(lfs, btree, bid,
tag_, weight_, &data);
if (err) {
return err;
}
return lfsr_data_read(lfs, data, 0, buffer, size);
}
// TODO should lfsr_btree_lookupnext/lfsr_btree_parent be deduplicated?
static int lfsr_btree_parent(lfs_t *lfs,
const lfsr_btree_t *btree, lfs_size_t bid, const lfsr_rbyd_t *child,
lfsr_rbyd_t *rbyd_, lfs_ssize_t *rid_) {
// inlined? root?
if (bid >= lfsr_btree_weight(btree)
|| lfsr_btree_isinlined(btree)
|| (btree->u.r.rbyd.block == child->block
&& btree->u.r.rbyd.trunk == child->trunk)) {
return LFS_ERR_NOENT;
}
// descend down the btree looking for our id
lfsr_rbyd_t branch = btree->u.r.rbyd;
lfs_ssize_t rid = bid;
while (true) {
// each branch is a pair of optional name + on-disk structure
lfs_ssize_t rid__;
lfsr_tag_t tag__;
// TODO do we really need to fetch weight__ if we get it in our
// btree struct?
// TODO maybe only when validating?
lfs_size_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_lookup(lfs, &branch, rid__, LFSR_TAG_WIDESTRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// didn't find our child?
if (tag__ != LFSR_TAG_BTREE) {
return LFS_ERR_NOENT;
}
// adjust rid with subtree's weight
rid -= (rid__ - (weight__-1));
// fetch the next branch
lfsr_rbyd_t branch_;
lfs_ssize_t d = lfsr_branch_fromdisk(lfs, &branch_, data__);
if (d < 0) {
return d;
}
LFS_ASSERT(branch_.weight == weight__);
// found our child?
if (branch_.block == child->block && branch_.trunk == child->trunk) {
// TODO how many of these should be conditional?
if (rbyd_) {
*rbyd_ = branch;
}
if (rid_) {
*rid_ = rid__;
}
return 0;
}
branch = branch_;
}
}
// we need some scratch space for tail-recursive attr in lfsr_btree_commit
//
// note this is a mix of attributes and their payloads
// note also we need this to be a const expression since it's used in
// array allocations
#define LFSR_BTREE_SCRATCHATTRS ( \
4 \
+ ((2*LFSR_BRANCH_DSIZE) + sizeof(lfsr_attr_t)-1) \
/ sizeof(lfsr_attr_t))
// this macro creates an attr list with enough reserved space for
// btree commit operations, it's ugly but likely any implementation
// of this will look ugly since we can't use things like lfs_min32 in
// an array declaration
#define LFSR_BTREE_ATTRS(...) \
(lfsr_attr_t[ \
sizeof((lfsr_attr_t[]){__VA_ARGS__}) / sizeof(lfsr_attr_t) \
> LFSR_BTREE_SCRATCHATTRS \
? sizeof((lfsr_attr_t[]){__VA_ARGS__}) / sizeof(lfsr_attr_t) \
: LFSR_BTREE_SCRATCHATTRS \
]){__VA_ARGS__}, \
sizeof((lfsr_attr_t[]){__VA_ARGS__}) / sizeof(lfsr_attr_t)
// core btree algorithm
static int lfsr_btree_commit(lfs_t *lfs,
lfsr_btree_t *btree, lfs_size_t bid, lfs_ssize_t cutoff,
lfsr_rbyd_t *rbyd,
lfsr_attr_t attrs[static LFSR_BTREE_SCRATCHATTRS],
lfs_size_t attr_count) {
// other layers should check for inlined btrees before this
LFS_ASSERT(!lfsr_btree_isinlined(btree));
while (true) {
// we will always need our parent, so go ahead and find it
lfsr_rbyd_t parent;
lfs_ssize_t pid;
int err = lfsr_btree_parent(lfs, btree, bid, rbyd, &parent, &pid);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
// mark pid as -1 if we have no parent
pid = -1;
}
lfs_size_t pweight = rbyd->weight;
// 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 strange benefit is we cache the root of our btree this way
if (!lfsr_rbyd_isfetched(rbyd)) {
err = lfsr_rbyd_fetch(lfs, rbyd, rbyd->block, rbyd->trunk);
if (err) {
return err;
}
}
// is rbyd erased? can we sneak our commit into any remaining
// erased bytes? note that the btree limit prevents this from mutating
// other references to the rbyd
err = lfsr_rbyd_commit(lfs, rbyd, attrs, attr_count);
if (err && err != LFS_ERR_RANGE) {
// TODO wait should we also move if there is corruption here?
return err;
}
if (err) {
goto compact;
}
// done?
if (pid == -1) {
break;
}
// cannibalize some attributes in our attr list to store
// our branch
uint8_t *scratch_buf = (uint8_t*)&attrs[2];
lfs_ssize_t d = lfsr_branch_todisk(lfs, rbyd, scratch_buf);
if (d < 0) {
return d;
}
// prepare commit to parent, tail recursing upwards
//
// note that since we defer merges to compaction time, we can
// end up removing an rbyd here
if (rbyd->weight == 0) {
attrs[0] = LFSR_ATTR(pid, UNR, +rbyd->weight-pweight,
scratch_buf, d);
attr_count = 1;
} else {
attrs[0] = LFSR_ATTR(pid, GROW, +rbyd->weight-pweight, NULL, 0);
attrs[1] = LFSR_ATTR(pid+rbyd->weight-pweight, BTREE, 0,
scratch_buf, d);
attr_count = 2;
}
*rbyd = parent;
cutoff = -1;
continue;
compact:;
// can't commit, try to compact
lfsr_rbyd_t rbyd_;
lfs_size_t split_id;
// first check if we are a degenerate root and can be reverted to
// an inlined btree
//
// This gets a bit weird since we're defering our pending
// attributes to after the compaction. When we can/can't be inlined
// depends on those attributes, but trying to evaluate attributes
// is complicated and expensive.
//
// Instead we just let the upper layers indicate a cutoff for when
// an rbyd can be inlined, and leave the inlining work up to the
// upper layers.
if (pid == -1) {
int degenerate = lfsr_rbyd_isdegenerate(lfs, rbyd, cutoff);
if (degenerate) {
return degenerate;
}
}
// check if we're within our compaction threshold, otherwise we
// need to split
lfs_ssize_t estimate = lfsr_rbyd_estimateall(lfs, rbyd, -1, -1,
&split_id);
if (estimate < 0) {
return estimate;
}
if ((lfs_size_t)estimate > lfs->cfg->block_size/2) {
// need to split
goto split;
}
// allocate a new rbyd
err = lfsr_rbyd_alloc(lfs, &rbyd_);
if (err) {
return err;
}
// try to compact
err = lfsr_rbyd_compact(lfs, &rbyd_, 0, -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_appendall(lfs, &rbyd_, 0, -1,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// TODO do we really need a threshold for this? should we just
// always try since this only happens on compaction and our merges
// are defered?
// TODO should we allow merging both siblings?
// TODO we should have a benchmark for how removes affect tree size
// is our compacted size too small? try to merge with one of
// our siblings
if (rbyd_.off < lfs->cfg->block_size/4) {
goto merge;
merge_abort:;
}
// finalize commit
err = lfsr_rbyd_commit(lfs, &rbyd_, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
*rbyd = rbyd_;
// done?
if (pid == -1) {
break;
}
// cannibalize some attributes in our attr list to store
// our branch
scratch_buf = (uint8_t*)&attrs[2];
d = lfsr_branch_todisk(lfs, rbyd, scratch_buf);
if (d < 0) {
return d;
}
// prepare commit to parent, tail recursing upwards
//
// note that since we defer merges to compaction time, we can
// end up removing an rbyd here
if (rbyd->weight == 0) {
attrs[0] = LFSR_ATTR(pid, UNR, +rbyd->weight-pweight,
scratch_buf, d);
attr_count = 1;
} else {
attrs[0] = LFSR_ATTR(pid, GROW, +rbyd->weight-pweight, NULL, 0);
attrs[1] = LFSR_ATTR(pid+rbyd->weight-pweight, BTREE, 0,
scratch_buf, d);
attr_count = 2;
}
*rbyd = parent;
cutoff = -1;
continue;
split:;
// we should have something to split here
LFS_ASSERT(split_id > 0 && split_id < rbyd->weight);
// allocate a new rbyd
err = lfsr_rbyd_alloc(lfs, &rbyd_);
if (err) {
return err;
}
// allocate a sibling
lfsr_rbyd_t sibling;
err = lfsr_rbyd_alloc(lfs, &sibling);
if (err) {
return err;
}
// copy over tags < split_id
err = lfsr_rbyd_compact(lfs, &rbyd_, 0, split_id, rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append pending attrs < split_id
//
// upper layers should make sure this can't fail by limiting the
// maximum commit size
err = lfsr_rbyd_appendall(lfs, &rbyd_, 0, split_id,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// finalize commit
err = lfsr_rbyd_commit(lfs, &rbyd_, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// copy over tags >= split_id
err = lfsr_rbyd_compact(lfs, &sibling, split_id, -1, rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append pending attrs >= split_id
//
// upper layers should make sure this can't fail by limiting the
// maximum commit size
err = lfsr_rbyd_appendall(lfs, &sibling, split_id, -1,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// finalize commit
err = lfsr_rbyd_commit(lfs, &sibling, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
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_tag_t stag;
lfsr_data_t sdata;
err = lfsr_rbyd_lookupnext(lfs, &sibling, 0, LFSR_TAG_NAME,
NULL, &stag, NULL, &sdata);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// cannibalize some attributes in our attr list to store
// our branches
uint8_t *scratch_buf1 = (uint8_t*)&attrs[4];
uint8_t *scratch_buf2 = (uint8_t*)&attrs[4] + LFSR_BRANCH_DSIZE;
lfs_ssize_t d1 = lfsr_branch_todisk(lfs, &rbyd_, scratch_buf1);
if (d1 < 0) {
return d1;
}
lfs_ssize_t d2 = lfsr_branch_todisk(lfs, &sibling, scratch_buf2);
if (d2 < 0) {
return d2;
}
// no parent? introduce a new trunk
if (pid == -1) {
int err = lfsr_rbyd_alloc(lfs, &parent);
if (err) {
return err;
}
// prepare commit to parent, tail recursing upwards
attrs[0] = LFSR_ATTR(0, BTREE, +rbyd_.weight,
scratch_buf1, d1);
attrs[1] = (lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? LFSR_ATTR_DATA(rbyd_.weight, BRANCH, +sibling.weight,
sdata)
: LFSR_ATTR_NOOP);
attrs[2] = (lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? LFSR_ATTR(0+rbyd_.weight+sibling.weight-1, BTREE, 0,
scratch_buf2, d2)
: LFSR_ATTR(0+rbyd_.weight, BTREE, +sibling.weight,
scratch_buf2, d2));
attr_count = 3;
// yes parent? push up split
} else {
// prepare commit to parent, tail recursing upwards
attrs[0] = LFSR_ATTR(pid, GROW, +rbyd_.weight-pweight, NULL, 0);
attrs[1] = LFSR_ATTR(pid-(pweight-1)+rbyd_.weight-1, BTREE, 0,
scratch_buf1, d1);
attrs[2] = (lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? LFSR_ATTR_DATA(pid-(pweight-1)+rbyd_.weight,
BRANCH, +sibling.weight,
sdata)
: LFSR_ATTR_NOOP);
attrs[3] = (lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? LFSR_ATTR(pid-(pweight-1)+rbyd_.weight+sibling.weight-1,
BTREE, 0,
scratch_buf2, d2)
: LFSR_ATTR(pid-(pweight-1)+rbyd_.weight,
BTREE, +sibling.weight,
scratch_buf2, d2));
attr_count = 4;
}
*rbyd = parent;
cutoff = -1;
continue;
merge:;
// no parent? can't merge
if (pid == -1) {
goto merge_abort;
}
// only child? can't merge
if (pweight == parent.weight) {
goto merge_abort;
}
lfs_ssize_t sid;
lfs_ssize_t sdelta;
lfs_size_t sweight;
for (int i = 0;; i++) {
if (i >= 2) {
// no siblings can be merged
goto merge_abort;
}
// try the right sibling
if (i == 0) {
// right-most child? can't merge
if ((lfs_size_t)pid == parent.weight-1) {
continue;
}
sid = pid+1;
sdelta = rbyd_.weight;
// try the left sibling
} else {
// left-most child? can't merge
if ((lfs_size_t)pid-(pweight-1) == 0) {
continue;
}
sid = pid-pweight;
sdelta = 0;
}
// try looking up the sibling
// TODO do we really need to fetch sweight if we get it in our
// btree struct?
err = lfsr_rbyd_lookupnext(lfs, &parent, sid, LFSR_TAG_NAME,
&sid, &stag, &sweight, &sdata);
if (err) {
// no sibling? can't merge
if (err == LFS_ERR_NOENT) {
continue;
}
return err;
}
if (stag == LFSR_TAG_NAME) {
err = lfsr_rbyd_lookup(lfs, &parent,
sid, LFSR_TAG_WIDESTRUCT,
&stag, &sdata);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// no sibling? can't merge
if (stag != LFSR_TAG_BTREE) {
continue;
}
d = lfsr_branch_fromdisk(lfs, &sibling, sdata);
if (d < 0) {
return d;
}
LFS_ASSERT(sibling.weight == sweight);
// estimate if our sibling will fit
//
// this is imprecise when not compacting, so we may still fail to
// merge, but this at least lets us avoid wasting programming cycles
// when merge failure is obvious
lfs_ssize_t estimate = lfsr_rbyd_estimateall(lfs, &sibling, -1, -1,
NULL);
if (estimate < 0) {
return estimate;
}
// don't fit? can't merge
if ((lfs_size_t)estimate > lfs->cfg->block_size/4) {
continue;
}
// found a sibling
break;
}
// try to add our sibling's tags to our rbyd
lfs_size_t rweight_ = rbyd_.weight;
lfs_ssize_t id = 0;
lfsr_tag_t tag = 0;
while (true) {
lfs_size_t w;
lfsr_data_t data;
err = lfsr_rbyd_lookupnext(lfs, &sibling, id, lfsr_tag_next(tag),
&id, &tag, &w, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
break;
}
// append the attr
err = lfsr_rbyd_append(lfs, &rbyd_,
sdelta+id-lfs_smax32(w-1, 0), tag, +w,
data);
if (err) {
return err;
}
// if we exceed our compaction threshold our merge has failed,
// clean up ids and return to merge_abort
if (rbyd_.off > lfs->cfg->block_size/2) {
err = lfsr_rbyd_append(lfs, &rbyd_,
sdelta+(rbyd_.weight-rweight_)-1,
LFSR_TAG_UNR, -(rbyd_.weight-rweight_),
LFSR_DATA_NULL);
if (err) {
return err;
}
goto merge_abort;
}
}
if (sweight > 0 && rweight_ > 0) {
// bring in name that previously split the siblings
lfsr_tag_t split_tag;
lfsr_data_t split_data;
err = lfsr_rbyd_lookupnext(lfs, &parent,
(sdelta == 0 ? pid : sid), LFSR_TAG_NAME,
NULL, &split_tag, NULL, &split_data);
if (err) {
return err;
}
if (lfsr_tag_suptype(split_tag) == LFSR_TAG_NAME) {
// lookup the id (weight really) of the previously-split entry
lfs_ssize_t split_id;
err = lfsr_rbyd_lookupnext(lfs, &rbyd_,
(sdelta == 0 ? sweight : rweight_), LFSR_TAG_NAME,
&split_id, NULL, NULL, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
err = lfsr_rbyd_append(lfs, &rbyd_,
split_id, LFSR_TAG_BRANCH, 0, split_data);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
}
// finalize the commit
err = lfsr_rbyd_commit(lfs, &rbyd_, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// we must have a parent at this point, but is our parent degenerate?
LFS_ASSERT(pid != -1);
if (pweight+sweight == lfsr_btree_weight(btree)) {
// collapse our parent, decreasing the height of the tree
*rbyd = rbyd_;
break;
} else {
// make pid the lower child so the following math is easier
if (pid > sid) {
lfs_sswap32(&pid, &sid);
lfs_swap32(&pweight, &sweight);
}
// cannibalize some attributes in our attr list to store
// our branch
uint8_t *scratch_buf = (uint8_t*)&attrs[3];
lfs_ssize_t d = lfsr_branch_todisk(lfs, &rbyd_, scratch_buf);
if (d < 0) {
return d;
}
// prepare commit to parent, tail recursing upwards
attrs[0] = LFSR_ATTR(sid, UNR, -sweight, NULL, 0);
attrs[1] = LFSR_ATTR(pid, GROW, +rbyd_.weight-pweight, NULL, 0);
attrs[2] = LFSR_ATTR(pid+rbyd_.weight-pweight, BTREE, 0,
scratch_buf, d);
attr_count = 3;
}
*rbyd = parent;
cutoff = -1;
continue;
}
// at this point rbyd should be the trunk of our tree
btree->u.r.rbyd = *rbyd;
return false;
}
static int lfsr_btree_push(lfs_t *lfs, lfsr_btree_t *btree,
lfs_size_t bid, lfsr_tag_t tag, lfs_size_t weight, lfsr_data_t data) {
LFS_ASSERT(bid <= lfsr_btree_weight(btree));
// null btree?
if (lfsr_btree_isinlined(btree) && lfsr_btree_weight(btree) == 0) {
LFS_ASSERT(bid == 0);
// mark as inlined
btree->u.i.weight = 0x80000000 | weight;
btree->u.i.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->u.i.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->u.i.size = d;
return 0;
// inlined btree, need to expand into an rbyd
} else if (lfsr_btree_isinlined(btree)) {
lfsr_rbyd_t rbyd;
int err = lfsr_rbyd_alloc(lfs, &rbyd);
if (err) {
return err;
}
// commit our entries
err = lfsr_rbyd_commit(lfs, &rbyd, LFSR_ATTRS(
LFSR_ATTR_(0, btree->u.i.tag, +lfsr_btree_weight(btree),
btree->u.i.buffer, btree->u.i.size),
LFSR_ATTR_DATA_(bid, tag, +weight, data)));
if (err) {
return err;
}
btree->u.r.rbyd = rbyd;
return 0;
// a normal btree
} else {
// lookup in which leaf our id resides
//
// for lfsr_btree_commit operations to work out, we need to
// limit our bid to an id in the tree, which is what this min
// is doing
//
// note it is possible for our btree to have a weight of zero here,
// since we defer inlining until compaction time
lfs_size_t bid_ = lfs_min32(bid,
lfs_smax32(lfsr_btree_weight(btree)-1, 0));
lfsr_rbyd_t rbyd = btree->u.r.rbyd;
lfs_ssize_t rid = -1;
lfs_size_t rweight = 0;
int err = lfsr_btree_lookupnext_(lfs, btree, bid_,
NULL, &rbyd, &rid, NULL, &rweight, NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// adjust rid for push
if (bid >= lfsr_btree_weight(btree)) {
rid += 1;
} else {
rid -= rweight-1;
}
// commit our id into the tree, letting lfsr_btree_commit take care
// of the rest
int degenerate = lfsr_btree_commit(lfs, btree, bid_, 0, &rbyd,
LFSR_BTREE_ATTRS(
LFSR_ATTR_DATA_(rid, tag, +weight, data)));
if (degenerate < 0) {
return degenerate;
}
// revert to an inlined btree
if (degenerate) {
// mark as inlined
btree->u.i.weight = 0x80000000 | weight;
btree->u.i.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->u.i.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->u.i.size = d;
}
return 0;
}
}
static int lfsr_btree_set(lfs_t *lfs, lfsr_btree_t *btree,
lfs_size_t bid, lfsr_tag_t tag, lfs_size_t weight, lfsr_data_t data) {
LFS_ASSERT(bid < lfsr_btree_weight(btree));
LFS_ASSERT(lfsr_btree_weight(btree) > 0);
// inlined btree?
if (lfsr_btree_isinlined(btree)) {
LFS_ASSERT(bid == lfsr_btree_weight(btree)-1);
// mark as inlined
btree->u.i.weight = 0x80000000 | weight;
btree->u.i.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->u.i.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->u.i.size = d;
return 0;
// a normal btree
} else {
// lookup in which leaf our id resides
lfsr_rbyd_t rbyd;
lfsr_tag_t rtag;
lfs_ssize_t rid;
lfs_size_t rweight;
int err = lfsr_btree_lookupnext_(lfs, btree, bid,
NULL, &rbyd, &rid, &rtag, &rweight, NULL);
if (err) {
return err;
}
// commit our id into the tree, letting lfsr_btree_commit take care
// of the rest
int degenerate = lfsr_btree_commit(lfs, btree, bid, 1, &rbyd,
LFSR_BTREE_ATTRS(
(tag != rtag
? LFSR_ATTR_(rid, lfsr_tag_setrm(rtag), 0, NULL, 0)
: LFSR_ATTR_NOOP),
LFSR_ATTR_DATA_(rid, tag, 0, data),
LFSR_ATTR(rid, GROW, +weight-rweight, NULL, 0)));
if (degenerate < 0) {
return degenerate;
}
// revert to an inlined btree
if (degenerate) {
// mark as inlined
btree->u.i.weight = 0x80000000 | weight;
btree->u.i.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->u.i.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->u.i.size = d;
}
return 0;
}
}
static int lfsr_btree_pop(lfs_t *lfs, lfsr_btree_t *btree, lfs_size_t bid) {
LFS_ASSERT(bid < lfsr_btree_weight(btree));
LFS_ASSERT(lfsr_btree_weight(btree) > 0);
// inlined btree?
if (lfsr_btree_isinlined(btree)) {
LFS_ASSERT(bid == lfsr_btree_weight(btree)-1);
*btree = LFSR_BTREE_NULL;
return 0;
// a normal btree
} else {
// lookup in which leaf our id resides
lfsr_rbyd_t rbyd;
lfsr_tag_t rtag;
lfs_ssize_t rid;
lfs_size_t rweight;
int err = lfsr_btree_lookupnext_(lfs, btree, bid,
NULL, &rbyd, &rid, &rtag, &rweight, NULL);
if (err) {
return err;
}
// remove our id, letting lfsr_btree_commit take care
// of the rest
//
// note we use a cutoff of 2 here, if we have 2 entries before
// the commit, we should have 1 entry after the commit and can
// revert to an inlined btree
int degenerate = lfsr_btree_commit(lfs, btree, bid, 2, &rbyd,
LFSR_BTREE_ATTRS(
LFSR_ATTR(rid, UNR, -rweight, NULL, 0)));
if (degenerate < 0) {
return degenerate;
}
// revert to a null btree
if (degenerate && rweight >= rbyd.weight) {
*btree = LFSR_BTREE_NULL;
// revert to an inlined btree
} else if (degenerate) {
lfs_ssize_t sid;
// left sibling
if ((lfs_size_t)rid == rbyd.weight-1) {
sid = rid-rweight;
// right sibling
} else {
sid = rid+1;
}
lfsr_tag_t stag;
lfs_size_t sweight;
lfsr_data_t sdata;
int err = lfsr_rbyd_lookupnext(lfs, &rbyd, sid, LFSR_TAG_NAME,
&sid, &stag, &sweight, &sdata);
if (err) {
LFS_ASSERT(err == LFS_ERR_NOENT);
return err;
}
if (lfsr_tag_suptype(stag) == LFSR_TAG_NAME) {
err = lfsr_rbyd_lookup(lfs, &rbyd, sid, LFSR_TAG_WIDESTRUCT,
&stag, &sdata);
if (err) {
LFS_ASSERT(err == LFS_ERR_NOENT);
return err;
}
}
LFS_ASSERT(sweight+rweight == rbyd.weight);
// mark as inlined
btree->u.i.weight = 0x80000000 | sweight;
btree->u.i.tag = stag;
LFS_ASSERT(lfsr_data_size(sdata) <= LFSR_BTREE_INLINESIZE);
err = lfsr_bd_read(lfs, sdata.disk.block, sdata.disk.off, 0,
btree->u.i.buffer, lfsr_data_size(sdata));
if (err) {
return err;
}
btree->u.i.size = lfsr_data_size(sdata);
}
return 0;
}
}
// lfsr_btree_split can be done with a update+push, but this function
// does all this in one commit, which is much more efficient
//
// this is also the only btree function that creates name entries, in theory
// push could as well, we just don't need the functionality for littlefs
//
static int lfsr_btree_split(lfs_t *lfs, lfsr_btree_t *btree,
lfs_size_t bid, lfsr_data_t name,
lfsr_tag_t tag1, lfs_size_t weight1, lfsr_data_t data1,
lfsr_tag_t tag2, lfs_size_t weight2, lfsr_data_t data2) {
LFS_ASSERT(bid < lfsr_btree_weight(btree));
LFS_ASSERT(lfsr_btree_weight(btree) > 0);
// inlined btree, need to expand into an rbyd
if (lfsr_btree_isinlined(btree)) {
lfsr_rbyd_t rbyd;
int err = lfsr_rbyd_alloc(lfs, &rbyd);
if (err) {
return err;
}
// commit our entries
err = lfsr_rbyd_commit(lfs, &rbyd, LFSR_ATTRS(
LFSR_ATTR_DATA_(0, tag1, +weight1, data1),
(lfsr_data_size(name) > 0
? LFSR_ATTR_DATA(weight1, BRANCH, +weight2, name)
: LFSR_ATTR_NOOP),
(lfsr_data_size(name) > 0
? LFSR_ATTR_DATA_(weight1+weight2-1, tag2, 0, data2)
: LFSR_ATTR_DATA_(weight1, tag2, +weight2, data2))));
if (err) {
return err;
}
btree->u.r.rbyd = rbyd;
return 0;
// a normal btree
} else {
// lookup in which leaf our bid resides
lfsr_rbyd_t rbyd;
lfs_ssize_t rid;
lfs_size_t rweight;
int err = lfsr_btree_lookupnext_(lfs, btree, bid,
NULL, &rbyd, &rid, NULL, &rweight, NULL);
if (err) {
return err;
}
// commit our bid into the tree, letting lfsr_btree_commit take care
// of the rest
int degenerate = lfsr_btree_commit(lfs, btree, bid, -1, &rbyd,
LFSR_BTREE_ATTRS(
LFSR_ATTR(rid, GROW, +weight1-rweight, NULL, 0),
LFSR_ATTR_DATA_(rid-(rweight-1)+weight1-1, tag1, 0, data1),
(lfsr_data_size(name) > 0
? LFSR_ATTR_DATA(
rid-(rweight-1)+weight1, BRANCH, +weight2,
name)
: LFSR_ATTR_NOOP),
(lfsr_data_size(name) > 0
? LFSR_ATTR_DATA_(rid-(rweight-1)+weight1+weight2-1,
tag2, 0, data2)
: LFSR_ATTR_DATA_(rid-(rweight-1)+weight1,
tag2, +weight2, data2))));
if (degenerate < 0) {
return degenerate;
}
// this should never happen
LFS_ASSERT(!degenerate);
return 0;
}
}
// lookup in a btree by name
static int lfsr_btree_namelookup(lfs_t *lfs, const lfsr_btree_t *btree,
lfs_size_t did, const char *name, lfs_size_t name_size,
lfs_size_t *bid_, lfsr_tag_t *tag_, lfs_size_t *weight_,
lfsr_data_t *data_) {
// an empty tree?
if (lfsr_btree_weight(btree) == 0) {
return LFS_ERR_NOENT;
}
// inlined?
if (lfsr_btree_isinlined(btree)) {
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = lfsr_btree_weight(btree)-1;
}
if (tag_) {
*tag_ = btree->u.i.tag;
}
if (weight_) {
*weight_ = lfsr_btree_weight(btree);
}
if (data_) {
*data_ = LFSR_DATA_BUF(btree->u.i.buffer, btree->u.i.size);
}
return 0;
}
// descend down the btree looking for our name
lfsr_rbyd_t branch = btree->u.r.rbyd;
lfs_ssize_t bid = 0;
while (true) {
// lookup our name in the rbyd via binary search
lfs_ssize_t rid__;
lfs_size_t weight__;
int err = lfsr_rbyd_namelookup(lfs, &branch, did, name, name_size,
&rid__, NULL, &weight__, NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// the name may not match exactly, but indicates which branch to follow
lfsr_tag_t tag__;
lfsr_data_t data__;
err = lfsr_rbyd_lookup(lfs, &branch, rid__, LFSR_TAG_WIDESTRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// found another branch
if (tag__ == LFSR_TAG_BTREE) {
// update our bid
bid += rid__ - (weight__-1);
// fetch the next branch
lfs_ssize_t d = lfsr_branch_fromdisk(lfs, &branch, data__);
if (d < 0) {
return d;
}
LFS_ASSERT(branch.weight == weight__);
// found our id
} 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 0;
}
}
}
// incremental btree traversal
//
// note this is different from iteration, iteration should use
// lfsr_btree_lookupnext, traversal includes inner entries
typedef struct lfsr_btree_traversal {
lfs_size_t bid;
lfs_ssize_t rid;
lfsr_rbyd_t branch;
} lfsr_btree_traversal_t;
#define LFSR_BTREE_TRAVERSAL_INIT ((lfsr_btree_traversal_t){ \
.bid = 0, \
.rid = 0, \
.branch.trunk = 0, \
.branch.weight = 0, \
})
static int lfsr_btree_traversal_next(lfs_t *lfs,
const lfsr_btree_t *btree,
lfsr_btree_traversal_t *traversal,
lfs_size_t *bid_, lfsr_tag_t *tag_, lfs_size_t *weight_,
lfsr_data_t *data_) {
while (true) {
// in range?
if (traversal->bid >= lfsr_btree_weight(btree)) {
return LFS_ERR_NOENT;
}
// inlined?
if (lfsr_btree_isinlined(btree)) {
// setup traversal to terminate next call
traversal->bid = lfsr_btree_weight(btree);
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = lfsr_btree_weight(btree)-1;
}
if (tag_) {
*tag_ = btree->u.i.tag;
}
if (weight_) {
*weight_ = lfsr_btree_weight(btree);
}
if (data_) {
*data_ = LFSR_DATA_BUF(btree->u.i.buffer, btree->u.i.size);
}
return 0;
}
// restart from the root
if ((lfs_size_t)traversal->rid >= traversal->branch.weight) {
traversal->bid += traversal->branch.weight;
traversal->rid = traversal->bid;
traversal->branch = btree->u.r.rbyd;
if (traversal->rid == 0) {
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = lfsr_btree_weight(btree)-1;
}
if (tag_) {
*tag_ = LFSR_TAG_BTREE;
}
if (weight_) {
*weight_ = lfsr_btree_weight(btree);
}
if (data_) {
// note btrees are returned decoded
*data_ = LFSR_DATA_BUF(&traversal->branch,
sizeof(lfsr_rbyd_t));
}
return 0;
}
// continue, mostly for range check
continue;
}
// descend down the tree
lfs_ssize_t rid__;
lfsr_tag_t tag__;
lfs_size_t weight__;
lfsr_data_t data__;
int err = lfsr_rbyd_lookupnext(lfs, &traversal->branch,
traversal->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_lookup(lfs, &traversal->branch,
rid__, LFSR_TAG_WIDESTRUCT,
&tag__, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// found another branch
if (tag__ == LFSR_TAG_BTREE) {
// adjust rid with subtree's weight
traversal->rid -= (rid__ - (weight__-1));
// fetch the next branch
lfs_ssize_t d = lfsr_branch_fromdisk(lfs,
&traversal->branch, data__);
if (d < 0) {
return d;
}
LFS_ASSERT(traversal->branch.weight == weight__);
// return inner btree nodes if this is the first time we've
// seen them
if (traversal->rid == 0) {
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = traversal->bid + (rid__ - traversal->rid);
}
if (tag_) {
*tag_ = LFSR_TAG_BTREE;
}
if (weight_) {
*weight_ = traversal->branch.weight;
}
if (data_) {
// note btrees are returned decoded
*data_ = LFSR_DATA_BUF(
&traversal->branch, sizeof(lfsr_rbyd_t));
}
return 0;
}
// found our bid
} else {
// move on to the next rid
//
// note the effectively traverses a full leaf without redoing
// the btree walk
lfs_ssize_t bid__ = traversal->bid + (rid__ - traversal->rid);
traversal->rid = rid__ + 1;
// TODO how many of these should be conditional?
if (bid_) {
*bid_ = bid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
return 0;
}
}
}
/// Metadata pair operations ///
// the mroot anchor, mdir 0x{0,1} is the entry point into the filesystem
#define LFSR_MDIR_MROOTANCHOR ((const lfs_block_t[2]){0, 1})
static inline int lfsr_mdir_cmp(
const lfs_block_t a[static 2],
const lfs_block_t b[static 2]) {
// allow either order
if ((a[0] == b[0] && a[1] == b[1])
|| (a[0] == b[1] && a[1] == b[0])) {
return 0;
} else {
return 1;
}
}
static inline bool lfsr_mdir_ismrootanchor(
const lfs_block_t blocks[static 2]) {
// mrootanchor is always at 0x{0,1}
// just check that the first block is in mroot anchor range
return blocks[0] <= 1;
}
// 2 leb128 => 10 bytes (worst case)
#define LFSR_MDIR_DSIZE (5+5)
static lfs_ssize_t lfsr_mdir_todisk(lfs_t *lfs,
const lfs_block_t blocks[static 2],
uint8_t buffer[static LFSR_MDIR_DSIZE]) {
(void)lfs;
lfs_ssize_t d = 0;
for (int i = 0; i < 2; i++) {
lfs_ssize_t d_ = lfs_toleb128(blocks[i], &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
}
return d;
}
static lfs_ssize_t lfsr_mdir_fromdisk(lfs_t *lfs,
lfs_block_t blocks[static 2], lfsr_data_t data) {
lfs_ssize_t d = 0;
for (int i = 0; i < 2; i++) {
lfs_ssize_t d_ = lfsr_data_readleb128(lfs, data, d, &blocks[i]);
if (d_ < 0) {
return d_;
}
d += d_;
}
return d;
}
static inline bool lfsr_mdir_isdropped(const lfsr_mdir_t *mdir) {
return mdir->u.r.rbyd.trunk == 0;
}
// track opened mdirs that may need to by updated
static void lfsr_mdir_addopened(lfs_t *lfs,
uint8_t type, lfsr_openedmdir_t *opened) {
opened->next = lfs->opened[type];
lfs->opened[type] = opened;
}
static void lfsr_mdir_removeopened(lfs_t *lfs,
uint8_t type, lfsr_openedmdir_t *opened) {
for (lfsr_openedmdir_t **p = &lfs->opened[type]; *p; p = &(*p)->next) {
if (*p == opened) {
*p = (*p)->next;
break;
}
}
}
static bool lfsr_mdir_isopened(lfs_t *lfs,
uint8_t type, const lfsr_openedmdir_t *opened) {
for (lfsr_openedmdir_t *p = lfs->opened[type]; p; p = p->next) {
if (p == opened) {
return true;
}
}
return false;
}
// actual mdir functions
static int lfsr_mdir_fetch(lfs_t *lfs, lfsr_mdir_t *mdir,
const lfs_block_t blocks[static 2], lfsr_mid_t mid) {
// 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] = {blocks[0], 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->u.r.rbyd, blocks_[0], 0);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (!err) {
mdir->mid = mid;
// keep track of other block for compactions
mdir->u.r.redund_block = 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,
lfs_ssize_t id, lfsr_tag_t tag,
lfs_ssize_t *id_, lfsr_tag_t *tag_, lfsr_data_t *data_) {
return lfsr_rbyd_lookupnext(lfs, &mdir->u.r.rbyd, id, tag,
id_, tag_, NULL, data_);
}
static int lfsr_mdir_lookup(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfs_ssize_t id, lfsr_tag_t tag,
lfsr_tag_t *tag_, lfsr_data_t *data_) {
return lfsr_rbyd_lookup(lfs, &mdir->u.r.rbyd, id, tag, tag_, data_);
}
// TODO do we need this?
// TODO move this into the tests?
static lfs_ssize_t lfsr_mdir_get(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfs_ssize_t id, lfsr_tag_t tag, void *buffer, lfs_size_t size) {
return lfsr_rbyd_get(lfs, &mdir->u.r.rbyd, id, tag, buffer, size);
}
// some mdir-related gstate things we need
static void lfsr_fs_flushgdelta(lfs_t *lfs) {
memset(lfs->dgrm, 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_GRM, NULL, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
err = lfsr_grm_xor(lfs, lfs->dgrm, data);
if (err) {
return err;
}
}
return 0;
}
// mtree is the core tree of mdirs in littlefs
static inline bool lfsr_mtree_isinlined(lfs_t *lfs) {
return lfsr_btree_weight(&lfs->mtree) == 0;
}
static inline lfs_size_t lfsr_mtree_weight(lfs_t *lfs) {
return lfsr_btree_weight(&lfs->mtree);
}
static int lfsr_mtree_lookup(lfs_t *lfs, lfsr_mid_t mid, lfsr_mdir_t *mdir_) {
// TODO should we really allow -1=>mroot lookup?
LFS_ASSERT(mid.bid >= -1);
LFS_ASSERT(mid.bid < (lfs_ssize_t)lfsr_mtree_weight(lfs));
// looking up mroot?
if (mid.bid < 0) {
mdir_->mid = mid;
mdir_->u = lfs->mroot.u;
return 0;
// look up mdir in actual mtree
} else {
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_btree_lookup(lfs, &lfs->mtree, mid.bid,
&tag, NULL, &data);
if (err) {
return err;
}
LFS_ASSERT(tag == LFSR_TAG_MDIR);
// decode mdir
lfs_ssize_t d = lfsr_mdir_fromdisk(lfs, mdir_->u.m.blocks, data);
if (d < 0) {
return d;
}
// fetch mdir
return lfsr_mdir_fetch(lfs, mdir_, mdir_->u.m.blocks, mid);
}
}
static int lfsr_mtree_parent(lfs_t *lfs, const lfs_block_t blocks[static 2],
lfsr_mdir_t *mparent_) {
// if mptr is our initial 0x{0,1} blocks, we have no parent
if (lfsr_mdir_ismrootanchor(blocks)) {
return LFS_ERR_NOENT;
}
// scan list of mroots for our requested pair
lfs_block_t blocks_[2] = {
LFSR_MDIR_MROOTANCHOR[0],
LFSR_MDIR_MROOTANCHOR[1]};
while (true) {
// fetch next possible superblock
lfsr_mdir_t mdir;
int err = lfsr_mdir_fetch(lfs, &mdir, blocks_, LFSR_MID(-1, -1));
if (err) {
return err;
}
// lookup next mroot
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &mdir, -1, LFSR_TAG_MROOT, NULL, &data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// decode mdir
lfs_ssize_t d = lfsr_mdir_fromdisk(lfs, blocks_, data);
if (d < 0) {
return d;
}
// found our child?
if (lfsr_mdir_cmp(blocks_, blocks) == 0) {
*mparent_ = mdir;
return 0;
}
}
}
static int lfsr_mtree_seek(lfs_t *lfs, lfsr_mdir_t *mdir, lfs_off_t off) {
// calculate new rid
lfs_ssize_t rid_ = mdir->mid.rid + 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_ >= (lfs_ssize_t)mdir->u.m.weight) {
lfsr_smbid_t bid_ = mdir->mid.bid + 1;
// end of mtree?
if (bid_ >= (lfs_ssize_t)lfsr_mtree_weight(lfs)) {
// TODO is this needed?
// make sure to update rid even if we error so seek will always
// return noent after the first noent
mdir->mid.rid = rid_;
return LFS_ERR_NOENT;
}
rid_ -= mdir->u.m.weight;
int err = lfsr_mtree_lookup(lfs, LFSR_MID(bid_, rid_), mdir);
if (err) {
return err;
}
}
mdir->mid.rid = rid_;
return 0;
}
// reason is an enum that determines the exact behavior of lfsr_mdir_compact_:
// - reason = compacting => only alloc if mdir is tired (wear-leveling)
// - reason = extending => never alloc (mroot anchor)
// - reason >= 0 => always alloc, use this as the new mid (new mdir)
enum {
LFSR_MDIR_COMPACTING = -3,
LFSR_MDIR_EXTENDING = -4,
};
// low-level mdir compaction
static int lfsr_mdir_compact_(lfs_t *lfs, lfsr_mdir_t *mdir_,
lfs_ssize_t reason,
lfs_ssize_t start_id, lfs_ssize_t end_id,
const lfsr_mdir_t *mdir,
const lfsr_attr_t *attr1s, lfs_size_t attr1_count,
const lfsr_attr_t *attr2s, lfs_size_t attr2_count) {
// first thing we need to do is read our current revision count
uint32_t rev;
int err = lfsr_bd_read(lfs, mdir->u.r.rbyd.block, 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 (reason != LFSR_MDIR_EXTENDING && (reason != LFSR_MDIR_COMPACTING || (
lfs->cfg->block_cycles > 0
// TODO rev things
&& (rev + 1) % lfs->cfg->block_cycles == 0))) {
// assign the new mid
mdir_->mid = LFSR_MID((reason >= 0 ? reason : mdir->mid.bid), -1);
// allocate two blocks
for (int i = 0; i < 2; i++) {
int err = lfs_alloc(lfs, &mdir_->u.m.blocks[i]);
if (err) {
return err;
}
}
// read the new revision count
//
// we use whatever is on-disk to avoid needing to rewrite the
// redund block
err = lfsr_bd_read(lfs, mdir_->u.r.rbyd.block, 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;
}
}
// only consume gstate here during normal compacts
if (reason == LFSR_MDIR_COMPACTING) {
// consume gstate on original rbyd, we need this even if we drop
// our mdir to avoid losing info
//
// if succesful, this should get immediately appended to our new commit
int err = lfsr_fs_consumegdelta(lfs, mdir);
if (err) {
return err;
}
}
// swap our rbyds
lfs_swap32(&mdir_->u.r.rbyd.block, &mdir_->u.r.redund_block);
mdir_->u.r.rbyd.weight = 0;
mdir_->u.r.rbyd.trunk = 0;
mdir_->u.r.rbyd.off = 0;
mdir_->u.r.rbyd.crc = 0;
// erase, preparing for compact
err = lfsr_bd_erase(lfs, mdir_->u.r.rbyd.block);
if (err) {
return err;
}
// increment our revision count and write it to our rbyd
// TODO rev things
err = lfsr_rbyd_appendrev(lfs, &mdir_->u.r.rbyd, rev + 1);
if (err) {
return err;
}
// copy over attrs
err = lfsr_rbyd_compact(lfs, &mdir_->u.r.rbyd,
start_id, end_id, &mdir->u.r.rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append any pending attrs
//
// upper layers should make sure this can't fail by limiting the
// maximum commit size
err = lfsr_rbyd_appendall(lfs, &mdir_->u.r.rbyd, start_id, end_id,
attr1s, attr1_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// note we don't filter attrs from our second pending list, this
// is used for some auxiliary attrs in lfsr_mdir_commit
err = lfsr_rbyd_appendall(lfs, &mdir_->u.r.rbyd, -1, -1,
attr2s, attr2_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// drop commit if weight goes to zero
if (mdir_->mid.bid >= 0 && mdir_->u.m.weight == 0) {
// TODO should we just make our pcache not assert?
// drop our pcache, we're not going to complete this commit
lfs_cache_zero(lfs, &lfs->pcache);
// finalize commit
} else {
// only append gstate if 1. we are not dropped, 2. we have not
// been relocated/split/etc, unless we are an mroot
//
// this pushes gstate up into the mroot when relocating, and
// helps avoid corner case issues when splitting/dropping
bool flushinggdelta = false;
if (mdir_->mid.bid == -1
|| lfsr_mdir_cmp(mdir_->u.m.blocks, mdir->u.m.blocks) == 0) {
err = lfsr_rbyd_appendgdelta(lfs, &mdir_->u.r.rbyd);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
flushinggdelta = true;
} else {
// consume gstate so we don't lose any info
err = lfsr_fs_consumegdelta(lfs, mdir_);
if (err) {
return err;
}
}
err = lfsr_rbyd_commit(lfs, &mdir_->u.r.rbyd, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// TODO avoid duplicate conditions somehow?
// success? gstate is committed
if (flushinggdelta) {
lfsr_fs_flushgdelta(lfs);
}
}
return 0;
}
// low-level mdir commit, does not handle mtree/mlist updates
static int lfsr_mdir_commit_(lfs_t *lfs, lfsr_mdir_t *mdir,
lfs_ssize_t start_id, lfs_ssize_t end_id,
lfs_size_t *split_id_,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// try to append a commit
lfsr_mdir_t mdir_ = *mdir;
// TODO handle this differently?
// TODO let the lower rbyd layer handle this somehow?
// mark mdir as unerased in case we fail
mdir->u.r.rbyd.off = lfs->cfg->block_size;
int err = lfsr_rbyd_appendall(lfs, &mdir_.u.r.rbyd, start_id, end_id,
attrs, attr_count);
if (err && err != LFS_ERR_RANGE) {
return err;
}
if (err == LFS_ERR_RANGE) {
goto compact;
}
// drop commit if weight goes to zero
if (mdir_.mid.bid >= 0 && mdir_.u.m.weight == 0) {
// TODO move this up into lfsr_mdir_commit?
// consume gstate so we don't lose any info
int err = lfsr_fs_consumegdelta(lfs, mdir);
if (err) {
return err;
}
// TODO should we just make our pcache not assert?
// drop our pcache, we're not going to complete this commit
lfs_cache_zero(lfs, &lfs->pcache);
} else {
// only append gstate if we are not dropping
err = lfsr_rbyd_appendgdelta(lfs, &mdir_.u.r.rbyd);
if (err && err != LFS_ERR_RANGE) {
return err;
}
if (err == LFS_ERR_RANGE) {
goto compact;
}
// finalize commit
err = lfsr_rbyd_commit(lfs, &mdir_.u.r.rbyd, NULL, 0);
if (err && err != LFS_ERR_RANGE) {
return err;
}
if (err == LFS_ERR_RANGE) {
goto compact;
}
// success? gstate is committed
lfsr_fs_flushgdelta(lfs);
}
// update our mdir
*mdir = mdir_;
return 0;
compact:;
// can't commit, try to compact
// check if we're within our compaction threshold
lfs_ssize_t estimate = lfsr_rbyd_estimateall(lfs, &mdir->u.r.rbyd,
start_id, end_id,
split_id_);
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;
}
// try to compact
err = lfsr_mdir_compact_(lfs, &mdir_, LFSR_MDIR_COMPACTING,
start_id, end_id, mdir,
attrs, attr_count,
NULL, 0);
if (err) {
return err;
}
// update our mdir
*mdir = mdir_;
return 0;
}
// high-level mdir commit
//
// this is also responsible for updating 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(!lfsr_mdir_isdropped(mdir));
LFS_ASSERT(mdir->mid.bid == -1 || mdir->u.m.weight > 0);
// parse out any pending gstate, these will get automatically xored
// with on-disk gdeltas in lower-level functions
lfsr_fs_flushgdelta(lfs);
for (lfs_size_t i = 0; i < attr_count; i++) {
if (attrs[i].tag == LFSR_TAG_GRM) {
// encode to disk
int err = lfsr_grm_todisk(lfs, attrs[i].d.grm, lfs->dgrm);
if (err) {
return err;
}
// xor with our current gstate to find our initial gdelta
err = lfsr_grm_xor(lfs, lfs->dgrm, LFSR_DATA_BUF(
lfs->pgrm, LFSR_GRM_DSIZE));
if (err) {
return err;
}
}
}
// attempt to commit/compact the mdir normally
lfsr_mdir_t mdir_ = *mdir;
lfs_size_t split_id;
int err = lfsr_mdir_commit_(lfs, &mdir_, -1, -1, &split_id,
attrs, attr_count);
if (err && err != LFS_ERR_RANGE) {
return err;
}
// handle possible mtree updates, this gets a bit messy
//
// note we need to make sure mroot_ is the most recent version of the
// mroot here, so failed commits are propagated correctly
//
// TODO wait, do we need to update lfs->mroot and mdir eagerly
// for the same reason?
lfsr_mdir_t mroot_ = (mdir->mid.bid == -1 ? mdir_ : lfs->mroot);
lfsr_mdir_t msibling_ = {.u.r.rbyd.trunk=0};
lfsr_btree_t mtree_ = lfs->mtree;
bool dirtymroot = false;
bool dirtymtree = false;
// need to split?
if (err == LFS_ERR_RANGE) {
// if we're the mroot, create a new mtree, assume the upper layers
// will take care of grafting our mtree into the mroot as needed
if (mdir->mid.bid == -1) {
// Create a null entry in our btree first. Don't worry! Thanks
// to inlining this doesn't allocate anything yet.
//
// The reason for this is twofold:
//
// 1. It makes it so the split logic is the same whether or not
// we're uninlining.
//
// 2. It makes it so we can actually split, lfsr_btree_split
// currently doesn't support an empty tree.
//
LFS_ASSERT(lfsr_btree_weight(&mtree_) == 0);
int err = lfsr_btree_push(lfs, &mtree_, 0, LFSR_TAG_MDIR, 1,
LFSR_DATA_NULL);
if (err) {
return err;
}
// 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
} else {
int err = lfsr_fs_consumegdelta(lfs, &mdir_);
if (err) {
return err;
}
}
// compact into new mdir tags < split_id
lfsr_smbid_t mbid = lfs_smax32(mdir->mid.bid, 0);
int err = lfsr_mdir_compact_(lfs, &mdir_, mbid, 0, split_id,
mdir, attrs, attr_count, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// compact into new mdir tags >= split_id
err = lfsr_mdir_compact_(lfs, &msibling_, mbid, split_id, -1,
mdir, attrs, attr_count, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
LFS_DEBUG("Splitting mdir %"PRId16" 0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}"
", 0x{%"PRIx32",%"PRIx32"}",
mdir->mid.bid,
mdir->u.m.blocks[0], mdir->u.m.blocks[1],
mdir_.u.m.blocks[0], mdir_.u.m.blocks[1],
msibling_.u.m.blocks[0], msibling_.u.m.blocks[1]);
// because of defered commits, both children can still be reduced
// to zero, need to catch this here
// both siblings reduced to zero
if (mdir_.u.m.weight == 0 && msibling_.u.m.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId16" 0x{%"PRIx32",%"PRIx32"}",
mdir_.mid.bid,
mdir_.u.m.blocks[0], mdir_.u.m.blocks[1]);
LFS_DEBUG("Dropping mdir %"PRId16" 0x{%"PRIx32",%"PRIx32"}",
msibling_.mid.bid,
msibling_.u.m.blocks[0], msibling_.u.m.blocks[1]);
// mark as dropped
mdir_.u.r.rbyd.trunk = 0;
msibling_.u.r.rbyd.trunk = 0;
// update our mtree
int err = lfsr_btree_pop(lfs, &mtree_, mbid);
if (err) {
return err;
}
// one sibling reduced to zero
} else if (mdir_.u.m.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId16" 0x{%"PRIx32",%"PRIx32"}",
mdir_.mid.bid,
mdir_.u.m.blocks[0], mdir_.u.m.blocks[1]);
// mark as dropped
mdir_.u.r.rbyd.trunk = 0;
// update our mtree
uint8_t buf[LFSR_MDIR_DSIZE];
lfs_ssize_t d = lfsr_mdir_todisk(lfs, msibling_.u.m.blocks, buf);
if (d < 0) {
return d;
}
int err = lfsr_btree_set(lfs, &mtree_, mbid, LFSR_TAG_MDIR, 1,
LFSR_DATA_BUF(buf, d));
if (err) {
return err;
}
// other sibling reduced to zero
} else if (msibling_.u.m.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId16" 0x{%"PRIx32",%"PRIx32"}",
msibling_.mid.bid,
msibling_.u.m.blocks[0], msibling_.u.m.blocks[1]);
// mark as dropped
msibling_.u.r.rbyd.trunk = 0;
// update our mtree
uint8_t buf[LFSR_MDIR_DSIZE];
lfs_ssize_t d = lfsr_mdir_todisk(lfs, mdir_.u.m.blocks, buf);
if (d < 0) {
return d;
}
int err = lfsr_btree_set(lfs, &mtree_, mbid, LFSR_TAG_MDIR, 1,
LFSR_DATA_BUF(buf, d));
if (err) {
return err;
}
// no siblings reduced to zero
} else {
// adjust our sibling's mid, do this here in case other sibling
// was dropped
msibling_.mid.bid += 1;
// update out mtree
// 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 stag;
lfsr_data_t sdata;
int err = lfsr_mdir_lookupnext(lfs, &msibling_, 0, LFSR_TAG_NAME,
NULL, &stag, &sdata);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
uint8_t buf1[LFSR_MDIR_DSIZE];
lfs_ssize_t d1 = lfsr_mdir_todisk(lfs, mdir_.u.m.blocks, buf1);
if (d1 < 0) {
return d1;
}
uint8_t buf2[LFSR_MDIR_DSIZE];
lfs_ssize_t d2 = lfsr_mdir_todisk(lfs, msibling_.u.m.blocks, buf2);
if (d2 < 0) {
return d2;
}
err = lfsr_btree_split(lfs, &mtree_, mbid,
(lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? sdata
: LFSR_DATA_NULL),
LFSR_TAG_MDIR, 1, LFSR_DATA_BUF(buf1, d1),
LFSR_TAG_MDIR, 1, LFSR_DATA_BUF(buf2, d2));
if (err) {
return err;
}
}
dirtymtree = true;
// mdir reduced to zero? need to drop?
} else if (mdir->mid.bid != -1 && mdir_.u.m.weight == 0) {
LFS_DEBUG("Dropping mdir %"PRId16" 0x{%"PRIx32",%"PRIx32"}",
mdir->mid.bid,
mdir->u.m.blocks[0], mdir->u.m.blocks[1]);
// mark as dropped
mdir_.u.r.rbyd.trunk = 0;
// update our mtree
int err = lfsr_btree_pop(lfs, &mtree_, mdir->mid.bid);
if (err) {
return err;
}
dirtymtree = true;
// need to relocate?
} else if (lfsr_mdir_cmp(mdir->u.m.blocks, mdir_.u.m.blocks) != 0) {
// relocate mroot
if (mdir->mid.bid == -1) {
// if we're relocating our root, just mark the root as dirty
// and let our dirtymroot code handle this
dirtymroot = true;
// relocate a normal mdir
} else {
LFS_DEBUG("Relocating mdir %"PRId16" 0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}",
mdir->mid.bid,
mdir->u.m.blocks[0], mdir->u.m.blocks[1],
mdir_.u.m.blocks[0], mdir_.u.m.blocks[1]);
// update our mtree
uint8_t buf[LFSR_MDIR_DSIZE];
lfs_ssize_t d = lfsr_mdir_todisk(lfs, mdir_.u.m.blocks, buf);
if (d < 0) {
return d;
}
int err = lfsr_btree_set(lfs, &mtree_,
mdir->mid.bid, LFSR_TAG_MDIR, 1,
LFSR_DATA_BUF(buf, d));
if (err) {
return err;
}
dirtymtree = true;
}
}
// before we continue we need to update our grm in case of splits/drops
//
// this gets pretty ugly
//
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 = attrs[i].d.grm;
uint8_t buf[LFSR_GRM_DSIZE];
int err = lfsr_grm_todisk(lfs, grm, buf);
if (err) {
return err;
}
err = lfsr_grm_xor(lfs, lfs->dgrm,
LFSR_DATA_BUF(buf, LFSR_GRM_DSIZE));
if (err) {
return err;
}
// fix our grm
for (uint8_t j = 0; j < 2; j++) {
if (grm->mids[j].bid == mdir->mid.bid) {
LFS_ASSERT(grm->mids[j].rid
<= (lfs_ssize_t)mdir->u.m.weight);
// TODO do we need this if we allow mid=0 => mroot when
// inlined?
// update mid if we are uninlining
grm->mids[j].bid = lfs_smax32(grm->mids[j].bid, 0);
if (grm->mids[j].rid >= (lfs_ssize_t)mdir_.u.m.weight) {
grm->mids[j].bid += 1;
grm->mids[j].rid -= mdir_.u.m.weight;
}
// update mid if we had a split or drop
} else if (grm->mids[j].bid > mdir->mid.bid
&& lfsr_btree_weight(&mtree_)
!= lfsr_mtree_weight(lfs)) {
grm->mids[j].bid += lfsr_btree_weight(&mtree_)
- lfsr_mtree_weight(lfs);
}
// TODO this is a big cludge, support for mid=0 when inlined?
// adjust mid if mtree is inlined
if (lfsr_btree_weight(&mtree_) == 0) {
LFS_ASSERT(grm->mids[j].bid <= 0);
if (grm->mids[j].bid == 0) {
grm->mids[j].bid = -1;
}
}
}
// xor our fix into our gdelta
err = lfsr_grm_todisk(lfs, grm, buf);
if (err) {
return err;
}
err = lfsr_grm_xor(lfs, lfs->dgrm,
LFSR_DATA_BUF(buf, LFSR_GRM_DSIZE));
if (err) {
return err;
}
}
}
// need to update mtree?
if (dirtymtree) {
LFS_ASSERT(mdir_.mid.bid != -1);
// commit mtree
lfsr_tag_t tag;
uint8_t buf[LFSR_BTREE_DSIZE];
lfs_ssize_t d = lfsr_btree_todisk(lfs, &mtree_, LFSR_TAG_MTREE,
&tag, buf);
if (d < 0) {
return d;
}
err = lfsr_mdir_commit_(lfs, &mroot_, -1, 0, NULL, LFSR_ATTRS(
LFSR_ATTR_(-1, tag, 0, buf, d)));
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
dirtymroot = (lfsr_mdir_cmp(
lfs->mroot.u.m.blocks,
mroot_.u.m.blocks) != 0);
}
// need to update mroot? tail recurse, updating mroots until a commit sticks
lfsr_mdir_t mchildroot = lfs->mroot;
lfs_block_t mchildroot_[2] = {mroot_.u.m.blocks[0], mroot_.u.m.blocks[1]};
while (dirtymroot) {
lfsr_mdir_t mparentroot;
int err = lfsr_mtree_parent(lfs, mchildroot.u.m.blocks,
&mparentroot);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
break;
}
LFS_DEBUG("Relocating mroot 0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}",
mchildroot.u.m.blocks[0], mchildroot.u.m.blocks[1],
mchildroot_[0], mchildroot_[1]);
// commit mrootchild
uint8_t buf[LFSR_MDIR_DSIZE];
lfs_ssize_t d = lfsr_mdir_todisk(lfs, mchildroot_, buf);
if (d < 0) {
return d;
}
mchildroot = mparentroot;
err = lfsr_mdir_commit_(lfs, &mparentroot, -1, -1, NULL, LFSR_ATTRS(
LFSR_ATTR(-1, MROOT, 0, buf, d)));
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
mchildroot_[0] = mparentroot.u.m.blocks[0];
mchildroot_[1] = mparentroot.u.m.blocks[1];
dirtymroot = (lfsr_mdir_cmp(
mchildroot.u.m.blocks,
mchildroot_) != 0);
}
// uh oh, we ran out of mrootparents, need to extend mroot chain
if (dirtymroot) {
// mchildroot should be our initial mroot at this point
LFS_ASSERT(lfsr_mdir_ismrootanchor(mchildroot.u.m.blocks));
LFS_DEBUG("Extending mroot 0x{%"PRIx32",%"PRIx32"}"
" -> 0x{%"PRIx32",%"PRIx32"}"
", 0x{%"PRIx32",%"PRIx32"}",
mchildroot.u.m.blocks[0], mchildroot.u.m.blocks[1],
mchildroot.u.m.blocks[0], mchildroot.u.m.blocks[1],
mchildroot_[0], mchildroot_[1]);
// copy magic/config from current mroot
lfsr_data_t magic;
err = lfsr_mdir_lookup(lfs, &mchildroot,
-1, LFSR_TAG_SUPERMAGIC, NULL, &magic);
if (err) {
return err;
}
lfsr_data_t config;
err = lfsr_mdir_lookup(lfs, &mchildroot,
-1, LFSR_TAG_SUPERCONFIG, NULL, &config);
if (err) {
return err;
}
// commit mrootchild
uint8_t buf[LFSR_MDIR_DSIZE];
lfs_ssize_t d = lfsr_mdir_todisk(lfs, mchildroot_, buf);
if (d < 0) {
return d;
}
// compact into mparentroot, this should stay our mroot anchor
lfsr_mdir_t mparentroot = mchildroot;
err = lfsr_mdir_compact_(lfs, &mparentroot, LFSR_MDIR_EXTENDING, 0, 0,
&mchildroot, NULL, 0, LFSR_ATTRS(
LFSR_ATTR_DATA(-1, SUPERMAGIC, 0, magic),
LFSR_ATTR_DATA(-1, SUPERCONFIG, 0, config),
// commit our new mchildroot
LFSR_ATTR(-1, MROOT, 0, buf, d)));
if (err) {
return err;
}
}
// success?? update in-device state
// gstate must have been committed by a lower-level function at this point
LFS_ASSERT(lfsr_grm_iszero(lfs->dgrm));
// update our gstate
for (lfs_size_t i = 0; i < attr_count; i++) {
if (attrs[i].tag == LFSR_TAG_GRM) {
lfs->grm = *attrs[i].d.grm;
// keep track of the exact encoding on-disk
int err = lfsr_grm_todisk(lfs, &lfs->grm, lfs->pgrm);
if (err) {
return err;
}
}
}
// update any opened mdirs
for (uint8_t type = 0; type < 2; type++) {
for (lfsr_openedmdir_t *opened = lfs->opened[type];
opened;
opened = opened->next) {
// avoid double updating current mdir, avoid updating dropped mdirs
if (&opened->mdir == mdir || lfsr_mdir_isdropped(&opened->mdir)) {
continue;
}
// kind of hacky, but this lets us iterate over both single
// mdirs and normal dirs which are pairs of mdirs
for (uint8_t j = 0; j <= type; j++) {
lfsr_mdir_t *opened_mdir = &(&opened->mdir)[j];
// first play out any attrs that change our rid
for (lfs_size_t i = 0; i < attr_count; i++) {
// TODO clean this up a bit?
// adjust opened mdirs?
if (opened_mdir->mid.bid == mdir->mid.bid
&& opened_mdir->mid.rid >= attrs[i].id) {
// removed?
if (opened_mdir->mid.rid
< attrs[i].id - attrs[i].delta) {
// normal mdirs mark as dropped
if (j == 0) {
opened_mdir->u.r.rbyd.trunk = 0;
goto next;
}
// for dir's second mdir (the position mdir), move
// on to the next rid
opened_mdir->mid.rid = attrs[i].id;
} else {
opened_mdir->mid.rid += attrs[i].delta;
// adjust dir position?
if (type == LFS_TYPE_DIR && j == 0) {
((lfsr_dir_t*)opened)->pos -= attrs[i].delta;
} else if (type == LFS_TYPE_DIR) {
((lfsr_dir_t*)opened)->pos += attrs[i].delta;
}
}
} else if (opened_mdir->mid.bid > mdir->mid.bid) {
// adjust dir position?
if (type == LFS_TYPE_DIR && j == 0) {
((lfsr_dir_t*)opened)->pos -= attrs[i].delta;
} else if (type == LFS_TYPE_DIR) {
((lfsr_dir_t*)opened)->pos += attrs[i].delta;
}
}
}
// update any opened mdirs if we had a split or drop
if (opened_mdir->mid.bid == mdir->mid.bid) {
if (!lfsr_mdir_isdropped(&msibling_)
&& opened_mdir->mid.rid
>= (lfs_ssize_t)mdir_.u.m.weight) {
LFS_ASSERT(lfsr_btree_weight(&mtree_)
!= lfsr_mtree_weight(lfs));
opened_mdir->mid.bid = msibling_.mid.bid;
opened_mdir->mid.rid -= mdir_.u.m.weight;
opened_mdir->u = msibling_.u;
} else {
opened_mdir->mid.bid = mdir_.mid.bid;
opened_mdir->u = mdir_.u;
}
} else if (opened_mdir->mid.bid > mdir->mid.bid) {
opened_mdir->mid.bid += lfsr_btree_weight(&mtree_)
- lfsr_mtree_weight(lfs);
}
}
next:;
}
}
// update mdir to follow requested rid
LFS_ASSERT(mdir->mid.rid <= (lfs_ssize_t)mdir->u.m.weight);
if (mdir->mid.bid == -1 && mdir->mid.rid == -1) {
mdir->u = mroot_.u;
} else if (!lfsr_mdir_isdropped(&msibling_)
&& mdir->mid.rid >= (lfs_ssize_t)mdir_.u.m.weight) {
LFS_ASSERT(lfsr_btree_weight(&mtree_) != lfsr_mtree_weight(lfs));
mdir->mid.bid = msibling_.mid.bid;
mdir->mid.rid -= mdir_.u.m.weight;
mdir->u = msibling_.u;
} else {
mdir->u = mdir_.u;
}
// update our mroot and mtree
lfs->mroot.u = mroot_.u;
lfs->mtree = mtree_;
return 0;
}
// lookup names in our mtree
static int lfsr_mdir_namelookup(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfs_size_t did, const char *name, lfs_size_t name_size,
lfs_ssize_t *id_, lfsr_tag_t *tag_, lfsr_data_t *data_) {
int err = lfsr_rbyd_namelookup(lfs, &mdir->u.r.rbyd,
did, name, name_size,
id_, tag_, NULL, data_);
// When not found, lfsr_rbyd_namelookup returns the id smaller than our
// expected name. This is correct for btree lookups, but not correct for
// mdir insertions. For mdirs we need to adjust this by 1 so we insert
// _after_ the smaller id.
if (id_ && err == LFS_ERR_NOENT) {
*id_ += 1;
}
return err;
}
// note if we fail, we at least leave mdir_/rid_ with the best place to insert
static int lfsr_mtree_namelookup(lfs_t *lfs,
lfs_size_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_isinlined(lfs)) {
mdir = lfs->mroot;
// lookup name in actual mtree
} else {
lfs_size_t bid;
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_btree_namelookup(lfs, &lfs->mtree,
did, name, name_size,
&bid, &tag, NULL, &data);
if (err) {
return err;
}
LFS_ASSERT(tag == LFSR_TAG_MDIR);
// decode mptr
lfs_ssize_t d = lfsr_mdir_fromdisk(lfs, mdir.u.m.blocks, data);
if (d < 0) {
return d;
}
// fetch mdir
err = lfsr_mdir_fetch(lfs, &mdir, mdir.u.m.blocks, LFSR_MID(bid, -1));
if (err) {
return err;
}
}
// and finally lookup name in our mdir
lfs_ssize_t rid;
int err = lfsr_mdir_namelookup(lfs, &mdir,
did, name, name_size,
&rid, tag_, data_);
// update mdir weith best place to insert even if we fail
mdir.mid.rid = rid;
if (mdir_) {
*mdir_ = mdir;
}
return err;
}
// special directory-ids
enum {
LFSR_DID_ROOT = 0,
};
// lookup full paths in our mtree
//
// 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,
// TODO originally path itself was a double pointer, is that a
// better design?
lfsr_mdir_t *mdir_, lfsr_tag_t *tag_,
lfs_size_t *did_, const char **name_, lfs_size_t *name_size_) {
// setup root
lfsr_mdir_t mdir;
mdir.mid = LFSR_MID(0, 0);
lfsr_tag_t tag = LFSR_TAG_DIR;
lfs_size_t did = LFSR_DID_ROOT;
if (mdir_) {
*mdir_ = mdir;
}
if (tag_) {
*tag_ = tag;
}
// we reduce path to a single name if we can find it
const char *name = path;
while (true) {
// skip slashes
name += strspn(name, "/");
lfs_size_t name_size = strcspn(name, "/");
// skip '.' and root '..'
if ((name_size == 1 && memcmp(name, ".", 1) == 0)
|| (name_size == 2 && memcmp(name, "..", 2) == 0)) {
name += name_size;
goto next;
}
// skip if matched by '..' in name
const char *suffix = name + 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) {
name = suffix + suffix_size;
goto next;
}
} else {
depth += 1;
}
suffix += suffix_size;
}
// found end of path, we must be done parsing our path now
if (name[0] == '\0') {
// generally we don't allow operations that change our root,
// report root as inval, but let upper layers intercept this
if (lfsr_mid_isroot(mdir.mid)) {
return LFS_ERR_INVAL;
}
return 0;
}
// only continue if we hit a directory
if (tag != LFSR_TAG_DIR) {
return LFS_ERR_NOTDIR;
}
// read the next did from the mdir if this is not the root
if (!lfsr_mid_isroot(mdir.mid)) {
lfsr_data_t data;
int err = lfsr_mdir_lookup(lfs, &mdir, mdir.mid.rid, LFSR_TAG_DID,
NULL, &data);
if (err) {
return err;
}
lfs_ssize_t d = lfsr_data_readleb128(lfs, data, 0, &did);
if (d < 0) {
return d;
}
}
// lookup up this name in the mtree
int err = lfsr_mtree_namelookup(lfs, did, name, name_size,
&mdir, &tag, NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// keep track of what we've seen, but only if we're the last name
// in our path
if (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;
}
}
// error if not found, note we update things first so mdir
// gets updated with where to insert correctly
if (err == LFS_ERR_NOENT) {
return LFS_ERR_NOENT;
}
// go on to next name
name += name_size;
next:;
}
}
// incremental mtree traversal
typedef struct lfsr_mtree_traversal {
// core traversal state
lfsr_mdir_t mdir;
lfsr_btree_traversal_t mtraversal;
uint8_t flags;
// cycle detection state
uint8_t tortoise_power;
lfs_size_t tortoise_step;
lfs_block_t tortoise_blocks[2];
} lfsr_mtree_traversal_t;
enum {
LFSR_MTREE_TRAVERSAL_VALIDATE = 0x1,
};
#define LFSR_MTREE_TRAVERSAL_INIT(_flags) ((lfsr_mtree_traversal_t){ \
.flags = _flags, \
.mdir.u.r.rbyd.trunk = 0, \
.mtraversal = LFSR_BTREE_TRAVERSAL_INIT, \
.tortoise_power = 0, \
.tortoise_step = 0, \
})
static int lfsr_mtree_traversal_next(lfs_t *lfs,
lfsr_mtree_traversal_t *traversal,
lfsr_mid_t *mid_, lfsr_tag_t *tag_, lfsr_data_t *data_) {
// new traversal? start with 0x{0,1}
//
// note we make sure to include fake mroots!
//
if (traversal->mdir.u.r.rbyd.trunk == 0) {
// fetch the first mroot 0x{0,1}
int err = lfsr_mdir_fetch(lfs, &traversal->mdir,
LFSR_MDIR_MROOTANCHOR, LFSR_MID(-1, -1));
if (err) {
return err;
}
if (mid_) {
*mid_ = LFSR_MID(-1, -1);
}
if (tag_) {
*tag_ = LFSR_TAG_MDIR;
}
if (data_) {
*data_ = LFSR_DATA_BUF(&traversal->mdir, sizeof(lfsr_mdir_t));
}
goto cycle_detect;
// check for mroot/mtree/mdir
} else if (traversal->mdir.mid.bid == -1) {
// lookup mroot, if we find one this is a fake mroot
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_mdir_lookup(lfs, &traversal->mdir,
-1, LFSR_TAG_WIDESTRUCT,
&tag, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// found a new mroot
if (err != LFS_ERR_NOENT && tag == LFSR_TAG_MROOT) {
lfs_ssize_t d = lfsr_mdir_fromdisk(lfs, traversal->mdir.u.m.blocks,
data);
if (d < 0) {
return d;
}
int err = lfsr_mdir_fetch(lfs, &traversal->mdir,
traversal->mdir.u.m.blocks, LFSR_MID(-1, -1));
if (err) {
return err;
}
if (mid_) {
*mid_ = LFSR_MID(-1, -1);
}
if (tag_) {
*tag_ = LFSR_TAG_MDIR;
}
if (data_) {
*data_ = LFSR_DATA_BUF(&traversal->mdir, sizeof(lfsr_mdir_t));
}
goto cycle_detect;
// no more mroots, which makes this our real mroot
} else {
// update our mroot
lfs->mroot = traversal->mdir;
// do we have an mtree? mdir?
if (err != LFS_ERR_NOENT) {
if (tag != LFSR_TAG_MDIR && tag != LFSR_TAG_MTREE) {
LFS_ERROR("Weird mstruct? (0x%"PRIx32")", tag);
return LFS_ERR_CORRUPT;
}
lfs_ssize_t d = lfsr_btree_fromdisk(lfs, &lfs->mtree,
LFSR_TAG_MTREE, tag, 1, data);
if (d < 0) {
return d;
}
// no mtree
} else {
lfs->mtree = LFSR_BTREE_NULL;
}
// initialize our mtree traversal
traversal->mtraversal = LFSR_BTREE_TRAVERSAL_INIT;
}
}
// traverse through the mtree
lfs_size_t bid;
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_btree_traversal_next(
lfs, &lfs->mtree, &traversal->mtraversal,
&bid, &tag, NULL, &data);
if (err) {
return err;
}
// inner btree nodes already decoded
if (tag == LFSR_TAG_BTREE) {
// validate our btree nodes if requested, this just means we need
// to do a full rbyd fetch and make sure the checksums match
if (traversal->flags & LFSR_MTREE_TRAVERSAL_VALIDATE) {
lfsr_rbyd_t *branch = (lfsr_rbyd_t*)data.buf.buffer;
lfsr_rbyd_t branch_;
int err = lfsr_rbyd_fetch(lfs, &branch_,
branch->block, branch->trunk);
if (err) {
if (err == LFS_ERR_CORRUPT) {
LFS_ERROR("Corrupted rbyd during mtree traversal "
"(0x%"PRIx32".%"PRIx32", 0x%08"PRIx32")",
branch->block, branch->trunk, branch->crc);
}
return err;
}
// test that our branch's crc matches what's expected
//
// it should be noted it's very unlikely for this to be hit without
// the above fetch failing since it includes both an internal
// crc check and trunk check
if (branch_.crc != branch->crc) {
LFS_ERROR("Checksum mismatch during mtree traversal "
"(0x%"PRIx32".%"PRIx32", "
"0x%08"PRIx32" != 0x%08"PRIx32")",
branch->block, branch->trunk,
branch_.crc, branch->crc);
return LFS_ERR_CORRUPT;
}
LFS_ASSERT(branch_.trunk == branch->trunk);
LFS_ASSERT(branch_.weight == branch->weight);
// TODO is this useful at all?
// change our branch to the fetched version
*branch = branch_;
}
// still update our mdir mid so we don't get stuck in a loop
// traversing mroots
traversal->mdir.mid.bid = bid;
if (mid_) {
*mid_ = LFSR_MID(bid, -1);
}
if (tag_) {
*tag_ = tag;
}
if (data_) {
*data_ = data;
}
return 0;
// fetch mdir if we're on a leaf
} else if (tag == LFSR_TAG_MDIR) {
lfs_ssize_t d = lfsr_mdir_fromdisk(lfs, traversal->mdir.u.m.blocks,
data);
if (d < 0) {
return d;
}
int err = lfsr_mdir_fetch(lfs, &traversal->mdir,
traversal->mdir.u.m.blocks, LFSR_MID(bid, -1));
if (err) {
return err;
}
if (mid_) {
*mid_ = LFSR_MID(bid, -1);
}
if (tag_) {
*tag_ = tag;
}
if (data_) {
*data_ = LFSR_DATA_BUF(&traversal->mdir, sizeof(lfsr_mdir_t));
}
goto cycle_detect;
} else {
LFS_ERROR("Weird mtree entry? (0x%"PRIx32")", tag);
return LFS_ERR_CORRUPT;
}
cycle_detect:;
// detect cycles with Brent's algorithm
//
// note we only consider mdirs here, the btree inner nodes
// require checksums of their pointers, so creating a valid
// cycle is actually quite difficult
//
if (lfsr_mdir_cmp(
traversal->mdir.u.m.blocks,
traversal->tortoise_blocks) == 0) {
LFS_ERROR("Cycle detected during mtree traversal "
"(0x{%"PRIx32",%"PRIx32"})",
traversal->mdir.u.m.blocks[0], traversal->mdir.u.m.blocks[1]);
return LFS_ERR_CORRUPT;
}
if (traversal->tortoise_step
== ((lfs_size_t)1 << traversal->tortoise_power)) {
traversal->tortoise_blocks[0] = traversal->mdir.u.m.blocks[0];
traversal->tortoise_blocks[1] = traversal->mdir.u.m.blocks[1];
traversal->tortoise_step = 0;
traversal->tortoise_power += 1;
}
traversal->tortoise_step += 1;
return 0;
}
/// Superblock things ///
// 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 csum_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)
// - 16-bit mtree_limit => 3 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+3+5+5+5)
static lfs_ssize_t lfsr_superconfig_todisk(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 csum 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);
if (d_ < 0) {
return d_;
}
d += d_;
// on-disk block count
d_ = lfs_toleb128(lfs->cfg->block_count, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
// on-disk utag limit
buffer[d] = 0x7f;
d += 1;
// on-disk mtree limit
d_ = lfs_toleb128(0x7fff, &buffer[d], 3);
if (d_ < 0) {
return d_;
}
d += d_;
// on-disk attr limit
d_ = lfs_toleb128(0x7fffffff, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
// on-disk name limit
d_ = lfs_toleb128(0xff, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
// on-disk file limit
d_ = lfs_toleb128(0x7fffffff, &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
return d;
}
/// 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_mountinited(lfs_t *lfs) {
// zero gdeltas, we'll read these from our mdirs
lfsr_fs_flushgdelta(lfs);
// traverse the mtree rooted at mroot 0x{1,0}
//
// note that lfsr_mtree_traversal_next will update our mroot/mtree
// based on what mroots it finds
//
// 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_mtree_traversal_t traversal = LFSR_MTREE_TRAVERSAL_INIT(
LFSR_MTREE_TRAVERSAL_VALIDATE);
while (true) {
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_mtree_traversal_next(lfs, &traversal,
NULL, &tag, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
break;
}
// we only care about mdirs here
if (tag != LFSR_TAG_MDIR) {
continue;
}
lfsr_mdir_t *mdir = (lfsr_mdir_t*)data.buf.buffer;
// found an mroot?
if (mdir->mid.bid == -1) {
// has magic string?
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, mdir, -1, LFSR_TAG_SUPERMAGIC,
NULL, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
lfs_scmp_t cmp = lfsr_data_cmp(lfs, data, 0, "littlefs", 8);
if (cmp < 0) {
return cmp;
}
// treat corrupted magic as no magic
if (lfs_cmp(cmp) != 0) {
err = LFS_ERR_NOENT;
}
}
if (err == LFS_ERR_NOENT) {
LFS_ERROR("No littlefs magic found");
return LFS_ERR_INVAL;
}
// lookup the superconfig
err = lfsr_mdir_lookup(lfs, mdir, -1, LFSR_TAG_SUPERCONFIG,
NULL, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
// check the major/minor version
uint32_t major_version;
uint32_t minor_version;
lfs_size_t d = 0;
lfs_ssize_t d_ = lfsr_data_readleb128(lfs, data, d,
&major_version);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
d_ = lfsr_data_readleb128(lfs, data, d, &minor_version);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
}
if (d_ == LFS_ERR_CORRUPT
|| major_version != LFS_DISK_VERSION_MAJOR
|| minor_version > LFS_DISK_VERSION_MINOR) {
LFS_ERROR("Incompatible version v%"PRIu32".%"PRIu32
" (!= v%"PRIu32".%"PRIu32")",
(d_ == LFS_ERR_CORRUPT
? (uint32_t)-1
: major_version),
(d_ == LFS_ERR_CORRUPT
? (uint32_t)-1
: minor_version),
LFS_DISK_VERSION_MAJOR,
LFS_DISK_VERSION_MINOR);
return LFS_ERR_INVAL;
}
// check the on-disk csum type
uint32_t csum_type;
d_ = lfsr_data_readleb128(lfs, data, d, &csum_type);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT || csum_type != 2) {
LFS_ERROR("Incompatible csum type 0x%"PRIx32
" (!= 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT ? (uint32_t)-1 : csum_type),
2);
return LFS_ERR_INVAL;
}
// check for any on-disk flags
uint32_t flags;
d_ = lfsr_data_readleb128(lfs, data, d, &flags);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT || flags != 0) {
LFS_ERROR("Incompatible flags 0x%"PRIx32
" (!= 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT ? (uint32_t)-1 : flags),
0);
return LFS_ERR_INVAL;
}
// check the on-disk block size
// TODO actually use this
uint32_t block_size;
d_ = lfsr_data_readleb128(lfs, data, d, &block_size);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT
|| block_size != lfs->cfg->block_size) {
LFS_ERROR("Incompatible block size 0x%"PRIx32
" (!= 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT ? (uint32_t)-1 : block_size),
lfs->cfg->block_size);
return LFS_ERR_INVAL;
}
// check the on-disk block count
// TODO actually use this
uint32_t block_count;
d_ = lfsr_data_readleb128(lfs, data, d, &block_count);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT
|| block_count != lfs->cfg->block_count) {
LFS_ERROR("Incompatible block count 0x%"PRIx32
" (!= 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT
? (uint32_t)-1
: block_count),
lfs->cfg->block_count);
return LFS_ERR_INVAL;
}
// check the on-disk utag limit
// TODO actually use this
uint32_t utag_limit;
d_ = lfsr_data_readleb128(lfs, data, d, &utag_limit);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT || utag_limit != 0x7f) {
LFS_ERROR("Incompatible utag limit 0x%"PRIx32
" (> 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT ? (uint32_t)-1 : utag_limit),
0x7f);
return LFS_ERR_INVAL;
}
// check the on-disk mtree limit
// TODO actually use this
uint32_t mtree_limit;
d_ = lfsr_data_readleb128(lfs, data, d, &mtree_limit);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT || mtree_limit != 0x7fff) {
LFS_ERROR("Incompatible mdir limit 0x%"PRIx32
" (> 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT
? (uint32_t)-1
: mtree_limit),
0x7fff);
return LFS_ERR_INVAL;
}
// check the on-disk attr limit
// TODO actually use this
uint32_t attr_limit;
d_ = lfsr_data_readleb128(lfs, data, d, &attr_limit);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT || attr_limit != 0x7fffffff) {
LFS_ERROR("Incompatible attr limit 0x%"PRIx32
" (> 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT ? (uint32_t)-1 : attr_limit),
0x7fffffff);
return LFS_ERR_INVAL;
}
// check the on-disk name limit
// TODO actually use this
uint32_t name_limit;
d_ = lfsr_data_readleb128(lfs, data, d, &name_limit);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT || name_limit != 0xff) {
LFS_ERROR("Incompatible name limit 0x%"PRIx32
" (> 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT ? (uint32_t)-1 : name_limit),
0xff);
return LFS_ERR_INVAL;
}
// check the on-disk file limit
// TODO actually use this
uint32_t file_limit;
d_ = lfsr_data_readleb128(lfs, data, d, &file_limit);
// treat any leb128 overflows as out-of-range values
if (d_ < 0 && d_ != LFS_ERR_CORRUPT) {
return d_;
}
if (d_ != LFS_ERR_CORRUPT) {
d += d_;
}
if (d_ == LFS_ERR_CORRUPT || file_limit != 0x7fffffff) {
LFS_ERROR("Incompatible file limit 0x%"PRIx32
" (> 0x%"PRIx32")",
(d_ == LFS_ERR_CORRUPT ? (uint32_t)-1 : file_limit),
0x7fffffff);
return LFS_ERR_INVAL;
}
}
}
// collect any gdeltas from this mdir
err = lfsr_fs_consumegdelta(lfs, mdir);
if (err) {
return err;
}
}
// 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->pgrm, lfs->dgrm, LFSR_GRM_DSIZE);
// decode grm so we can report any removed files as missing
lfs_ssize_t d = lfsr_grm_fromdisk(lfs, &lfs->grm, lfs->pgrm);
if (d < 0) {
return d;
}
if (lfsr_grm_hasrm(&lfs->grm)) {
LFS_DEBUG("Found pending grm %"PRId16".%"PRId16" %"PRId16".%"PRId16,
lfs->grm.mids[0].bid,
lfs->grm.mids[0].rid,
lfs->grm.mids[1].bid,
lfs->grm.mids[1].rid);
}
return 0;
}
static int lfsr_formatinited(lfs_t *lfs) {
uint8_t buf[LFSR_SUPERCONFIG_DSIZE];
lfs_ssize_t d = lfsr_superconfig_todisk(lfs, buf);
if (d < 0) {
return d;
}
for (uint32_t 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 = {.block=i, .off=0, .trunk=0};
int err = lfsr_bd_erase(lfs, rbyd.block);
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"
// - the superconfig, format-time configuration
// - the root's bookmark tag, which reserves did = 0 for the root
err = lfsr_rbyd_commit(lfs, &rbyd, LFSR_ATTRS(
LFSR_ATTR(-1, SUPERMAGIC, 0, "littlefs", 8),
LFSR_ATTR(-1, SUPERCONFIG, 0, buf, d),
LFSR_ATTR_NAME(0, BOOKMARK, +1, 0, NULL, 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" "
"(bs=%"PRId32", bc=%"PRId32")",
LFS_DISK_VERSION_MAJOR,
LFS_DISK_VERSION_MINOR,
lfs->cfg->block_size,
lfs->cfg->block_count);
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" "
"(bs=%"PRId32", bc=%"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 an ack, the block
// allocator may realloc any untracked blocks.
static void lfs_alloc_ack(lfs_t *lfs) {
lfs->lookahead.acked = 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_ack makes available for scanning
while (true) {
lfs->lookahead.next += 1;
lfs->lookahead.acked -= 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.acked -= 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 an "ack" before starting a set of allocaitons.
//
// If we've looked at all blocks since the last ack, we report the
// filesystem as out of storage.
//
if (lfs->lookahead.acked <= 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
// acked, 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.acked);
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_mtree_traversal_t traversal = LFSR_MTREE_TRAVERSAL_INIT(0);
while (true) {
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_mtree_traversal_next(lfs, &traversal,
NULL, &tag, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
break;
}
// TODO add block pointers here?
// mark any blocks we see at in-use, including any btree/mdir blocks
if (tag == LFSR_TAG_MDIR) {
lfsr_mdir_t *mdir = (lfsr_mdir_t*)data.buf.buffer;
lfs_alloc_setinuse(lfs, mdir->u.m.blocks[1]);
lfs_alloc_setinuse(lfs, mdir->u.m.blocks[0]);
} else if (tag == LFSR_TAG_BTREE) {
lfsr_rbyd_t *branch = (lfsr_rbyd_t*)data.buf.buffer;
lfs_alloc_setinuse(lfs, branch->block);
}
}
}
}
/// Directory operations ///
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_openedmdir_t parent;
lfs_size_t parent_did;
const char *name;
lfs_size_t name_size;
err = lfsr_mtree_pathlookup(lfs, path,
&parent.mdir, NULL,
&parent_did, &name, &name_size);
if (err && (err != LFS_ERR_NOENT || lfsr_mid_isroot(parent.mdir.mid))) {
return err;
}
// woah, already exists?
if (err != LFS_ERR_NOENT) {
return LFS_ERR_EXIST;
}
// check that name fits
if (name_size > lfs->name_max) {
return LFS_ERR_NAMETOOLONG;
}
// Our directory needs an arbitrary directory-id. 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.
//
lfs_size_t dmask = (1 << lfs_min32(
lfs_nlog2(lfsr_mtree_weight(lfs))
+ lfs_nlog2(lfs->cfg->block_size/32),
32)) - 1;
lfs_size_t did = lfs_crc32c(0, path, strlen(path)) & dmask;
// Check if we have a collision. If we do, search for the next
// available did
lfsr_mdir_t mdir;
while (true) {
int err = lfsr_mtree_namelookup(lfs, did, NULL, 0,
&mdir, NULL, NULL);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
break;
}
// try the next did
did = (did + 1) & dmask;
}
// found a good did, now to commit to the mtree
// Note when we write to the mtree, it's possible it changes our
// parent's mdir/rid. We can catch this by tracking our parent
// as "opened" temporarily
// TODO is this the best workaround for rid update issues?
parent.mdir.mid.rid -= 1;
lfsr_mdir_addopened(lfs, LFS_TYPE_REG, &parent);
// Conveniently, we just found where our bookmark should go. The bookmark
// tag is an empty entry that marks our directory as being allocated.
//
// We include a GRM here so the bookmark is automatically removed if we
// lose power before writing the entry in our parent
//
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
LFSR_ATTR_NAME(mdir.mid.rid, BOOKMARK, +1, did, NULL, 0),
LFSR_ATTR_GRM(-1, GRM, 0, &((lfsr_grm_t){{
mdir.mid,
LFSR_MID(-1, -1)}}))));
if (err) {
goto failed_with_parent;
}
lfsr_mdir_removeopened(lfs, LFS_TYPE_REG, &parent);
parent.mdir.mid.rid += 1;
// commit our new directory into our parent, zeroing out our grm
// in the process
err = lfsr_mdir_commit(lfs, &parent.mdir, LFSR_ATTRS(
LFSR_ATTR_NAME(parent.mdir.mid.rid, DIR, +1,
parent_did, name, name_size),
LFSR_ATTR_LEB128(parent.mdir.mid.rid, DID, 0, did),
LFSR_ATTR_GRM(-1, GRM, 0, &((lfsr_grm_t){{
LFSR_MID(-1, -1),
LFSR_MID(-1, -1)}}))));
if (err) {
return err;
}
return 0;
failed_with_parent:
lfsr_mdir_removeopened(lfs, LFS_TYPE_REG, &parent);
return err;
}
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;
err = lfsr_mtree_pathlookup(lfs, path,
&mdir, &tag,
NULL, NULL, NULL);
if (err) {
return err;
}
// 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;
int err = lfsr_mdir_lookup(lfs, &mdir, mdir.mid.rid, LFSR_TAG_DID,
NULL, &data);
if (err) {
return err;
}
lfs_size_t did;
lfs_ssize_t d = lfsr_data_readleb128(lfs, data, 0, &did);
if (d < 0) {
return d;
}
// then lookup the bookmark entry
lfsr_mdir_t mdir_;
err = lfsr_mtree_namelookup(lfs, did, NULL, 0,
&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, mdir_.mid);
// check that the directory is empty
err = lfsr_mtree_seek(lfs, &mdir_, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
lfsr_tag_t tag_;
err = lfsr_mdir_lookup(lfs, &mdir_,
mdir_.mid.rid, LFSR_TAG_WIDENAME,
&tag_, NULL);
if (err) {
return err;
}
if (tag_ != LFSR_TAG_BOOKMARK) {
return LFS_ERR_NOTEMPTY;
}
}
// adjust rid if grm is on the same mdir as our dir
if (grm.mids[0].bid == mdir.mid.bid
&& grm.mids[0].rid > mdir.mid.rid) {
grm.mids[0].rid -= 1;
}
}
// remove the metadata entry
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
LFSR_ATTR(mdir.mid.rid, UNR, -1, NULL, 0),
LFSR_ATTR_GRM(-1, GRM, 0, &grm)));
if (err) {
return err;
}
// 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) {
return err;
}
// 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;
lfs_size_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_NOENT || lfsr_mid_isroot(new_mdir.mid))) {
return err;
}
bool exists = (err != LFS_ERR_NOENT);
// there are a few cases we need to watch out for
if (!exists) {
// check that name fits
if (new_name_size > lfs->name_max) {
return LFS_ERR_NAMETOOLONG;
}
// adjust old rid if grm is on the same mdir as new rid
if (grm.mids[0].bid == new_mdir.mid.bid
&& grm.mids[0].rid >= new_mdir.mid.rid) {
grm.mids[0].rid += 1;
}
} else {
// renaming different types is an error
if (old_tag != new_tag) {
return LFS_ERR_ISDIR;
}
// TODO is it? is this check necessary?
// renaming to ourself is a noop
if (old_mdir.mid.bid == new_mdir.mid.bid
&& old_mdir.mid.rid == new_mdir.mid.rid) {
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;
int err = lfsr_mdir_lookup(lfs, &new_mdir,
new_mdir.mid.rid, LFSR_TAG_DID,
NULL, &data);
if (err) {
return err;
}
lfs_size_t did;
lfs_ssize_t d = lfsr_data_readleb128(lfs, data, 0, &did);
if (d < 0) {
return d;
}
// then lookup the bookmark entry
lfsr_mdir_t mdir_;
err = lfsr_mtree_namelookup(lfs, did, NULL, 0,
&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, mdir_.mid);
// check that the directory is empty
err = lfsr_mtree_seek(lfs, &mdir_, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
lfsr_tag_t tag_;
err = lfsr_mdir_lookup(lfs, &mdir_,
mdir_.mid.rid, LFSR_TAG_WIDENAME,
&tag_, NULL);
if (err) {
return err;
}
if (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(
(exists
? LFSR_ATTR(new_mdir.mid.rid, UNR, -1, NULL, 0)
: LFSR_ATTR_NOOP),
LFSR_ATTR_NAME_(new_mdir.mid.rid, old_tag, +1,
new_did, new_name, new_name_size),
LFSR_ATTR_MOVE(new_mdir.mid.rid, MOVE, 0, &old_mdir),
LFSR_ATTR_GRM(-1, GRM, 0, &grm)));
// we need to clean up any pending grms, fortunately we can leave
// this up to lfsr_fs_fixgrm
return lfsr_fs_fixgrm(lfs);
}
int lfsr_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
memset(info, 0, sizeof(struct lfs_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_INVAL) {
return err;
}
// special case for root
if (err == LFS_ERR_INVAL) {
strcpy(info->name, "/");
info->type = LFS_TYPE_DIR;
return 0;
}
// fill out our info struct
info->type = lfsr_tag_filetype(tag);
LFS_ASSERT(name_size <= LFS_NAME_MAX);
memcpy(info->name, name, name_size);
info->name[name_size] = '\0';
// TODO size once we have actual files
return 0;
}
int lfsr_dir_open(lfs_t *lfs, lfsr_dir_t *dir, const char *path) {
// 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_INVAL) {
return err;
}
// are we a directory?
if (tag != LFSR_TAG_DIR) {
return LFS_ERR_NOENT;
}
// read our did from the mdir, unless we're root
if (err == LFS_ERR_INVAL) {
dir->did = 0;
} else {
lfsr_data_t data;
int err = lfsr_mdir_lookup(lfs, &mdir, mdir.mid.rid, LFSR_TAG_DID,
NULL, &data);
if (err) {
return err;
}
lfs_ssize_t d = lfsr_data_readleb128(lfs, data, 0, &dir->did);
if (d < 0) {
return d;
}
}
// lookup our bookmark in the mtree
err = lfsr_mtree_namelookup(lfs, dir->did, NULL, 0,
&dir->bookmark_mdir, NULL, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// let rewind initialize pos/mdir state
err = lfsr_dir_rewind(lfs, dir);
if (err) {
return err;
}
// add to tracked mdirs
lfsr_mdir_addopened(lfs, LFS_TYPE_DIR, (lfsr_openedmdir_t*)dir);
return 0;
}
int lfsr_dir_close(lfs_t *lfs, lfsr_dir_t *dir) {
// remove from tracked mdirs
lfsr_mdir_removeopened(lfs, LFS_TYPE_DIR, (lfsr_openedmdir_t*)dir);
return 0;
}
int lfsr_dir_read(lfs_t *lfs, lfsr_dir_t *dir, struct lfs_info *info) {
memset(info, 0, sizeof(struct lfs_info));
// handle dots specially
if (dir->pos == 0) {
info->type = LFS_TYPE_DIR;
strcpy(info->name, ".");
dir->pos += 1;
return 0;
} else if (dir->pos == 1) {
info->type = LFS_TYPE_DIR;
strcpy(info->name, "..");
dir->pos += 1;
return 0;
}
// seek in case our mdir was dropped
int err = lfsr_mtree_seek(lfs, &dir->pos_mdir, 0);
if (err) {
return err;
}
// lookup our name tag
lfsr_tag_t tag;
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &dir->pos_mdir,
dir->pos_mdir.mid.rid, LFSR_TAG_WIDENAME,
&tag, &data);
if (err) {
return err;
}
// get our did
lfs_size_t did;
lfs_ssize_t d = lfsr_data_readleb128(lfs, data, 0, &did);
if (d < 0) {
return d;
}
// did mismatch? we must be done
if (did != dir->did) {
return LFS_ERR_NOENT;
}
// get file name from the name entry
LFS_ASSERT(lfsr_data_size(data)-d <= LFS_NAME_MAX);
d = lfsr_data_read(lfs, data, d, info->name, LFS_NAME_MAX);
if (d < 0) {
return d;
}
info->name[d] = '\0';
// get file type from the tag
info->type = lfsr_tag_filetype(tag);
// TODO get size once we actually have regular files
// eagerly look up the next entry
err = lfsr_mtree_seek(lfs, &dir->pos_mdir, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
dir->pos += 1;
return 0;
}
int lfsr_dir_seek(lfs_t *lfs, lfsr_dir_t *dir, lfs_off_t off) {
// 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->pos_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_mdir_isdropped(&dir->bookmark_mdir)) {
return 0;
}
// reset pos
dir->pos = 0;
// copy bookmark mdir and eagerly look up the next entry
//
// this makes handling of corner cases with mixed removes/dir reads easier
dir->pos_mdir = dir->bookmark_mdir;
int err = lfsr_mtree_seek(lfs, &dir->pos_mdir, 1);
if (err && err != LFS_ERR_NOENT) {
return err;
}
return 0;
}
/// 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.mids[0].bid < (lfs_ssize_t)lfsr_mtree_weight(lfs));
int err = lfsr_mtree_lookup(lfs, lfs->grm.mids[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 (grm.mids[0].bid == mdir.mid.bid
&& grm.mids[0].rid >= mdir.mid.rid) {
LFS_ASSERT(grm.mids[0].rid != mdir.mid.rid);
grm.mids[0].rid -= 1;
}
// remove the rid while also updating our grm
LFS_ASSERT(lfs->grm.mids[0].rid < (lfs_ssize_t)mdir.u.m.weight);
err = lfsr_mdir_commit(lfs, &mdir, LFSR_ATTRS(
LFSR_ATTR(mdir.mid.rid, UNR, -1, NULL, 0),
LFSR_ATTR_GRM(-1, GRM, 0, &grm)));
}
return 0;
}
static int lfsr_fs_preparemutation(lfs_t *lfs) {
// checkpoint the allocator
lfs_alloc_ack(lfs);
// fix pending grms
if (lfsr_grm_hasrm(&lfs->grm)) {
LFS_DEBUG("Fixing grm %"PRId16".%"PRId16" %"PRId16".%"PRId16,
lfs->grm.mids[0].bid,
lfs->grm.mids[0].rid,
lfs->grm.mids[1].bid,
lfs->grm.mids[1].rid);
int err = lfsr_fs_fixgrm(lfs);
if (err) {
return err;
}
// checkpoint the allocator again since our fixgrm completed some
// work
lfs_alloc_ack(lfs);
}
return 0;
}
///// 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->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 cleanup;
}
}
// 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 cleanup;
}
}
// 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 cleanup;
}
}
lfs->lookahead.start = 0;
lfs->lookahead.size = 0;
lfs->lookahead.next = 0;
lfs->lookahead.acked = 0;
// check that the size limits are sane
LFS_ASSERT(lfs->cfg->name_max <= LFS_NAME_MAX);
lfs->name_max = lfs->cfg->name_max;
if (!lfs->name_max) {
lfs->name_max = LFS_NAME_MAX;
}
LFS_ASSERT(lfs->cfg->file_max <= LFS_FILE_MAX);
lfs->file_max = lfs->cfg->file_max;
if (!lfs->file_max) {
lfs->file_max = LFS_FILE_MAX;
}
LFS_ASSERT(lfs->cfg->attr_max <= LFS_ATTR_MAX);
lfs->attr_max = lfs->cfg->attr_max;
if (!lfs->attr_max) {
lfs->attr_max = LFS_ATTR_MAX;
}
LFS_ASSERT(lfs->cfg->metadata_max <= lfs->cfg->block_size);
// 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?
// zero linked-lists of opened mdirs
lfs->opened[LFS_TYPE_REG] = NULL;
lfs->opened[LFS_TYPE_DIR] = NULL;
// zero gstate
memset(lfs->pgrm, 0, LFSR_GRM_DSIZE);
memset(lfs->dgrm, 0, LFSR_GRM_DSIZE);
return 0;
cleanup:
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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