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ef4fb9d3d3832bc44ff5175e2ff34051510bdf3e
littlefs/lfs.c
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Christopher Haster ef4fb9d3d3 Added specific tests to cover complex mdir split/drop corner cases 
Dropped the high-level "large entry" tests in exchange for these low-level
tests. The high-level tests accomplished the same thing, but worse and
less reliably.

Added some rough fixes (this whole code path needs to be rewritten).

Also made lfsr_rbyd_bisect a bit better behaved when dealing with a
small number of large entries. This was necessary for the split/drop
corner case tests since these rely on precise control of when mdirs
split.
2023-05-30 14:57:45 -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"
// some constants used throughout the code
#define LFS_BLOCK_NULL ((lfs_block_t)-1)
#define LFS_BLOCK_INLINE ((lfs_block_t)-2)
enum {
LFS_OK_RELOCATED = 1,
LFS_OK_DROPPED = 2,
LFS_OK_ORPHANED = 3,
};
enum {
LFS_CMP_EQ = 0,
LFS_CMP_LT = 1,
LFS_CMP_GT = 2,
};
/// 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);
int res = lfs_bd_cmp(lfs,
NULL, rcache, diff,
pcache->block, pcache->off, pcache->buffer, diff);
if (res < 0) {
return res;
}
if (res != LFS_CMP_EQ) {
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 int 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,
int *cmp) {
// check for in-bounds
if (off+size > lfs->cfg->block_size) {
return LFS_ERR_RANGE;
}
int res = lfs_bd_cmp(lfs, &lfs->pcache, &lfs->rcache, hint,
block, off, buffer, size);
if (res < 0) {
return res;
}
// TODO this should be eventually flattened away
if (res == LFS_CMP_EQ) {
*cmp = 0;
} else if (res == LFS_CMP_LT) {
*cmp = -1;
} else {
*cmp = +1;
}
return 0;
}
// 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_UNR = 0x0002,
LFSR_TAG_MKUNR = 0x0006, // in-device only
LFSR_TAG_MAGIC = 0x0030,
LFSR_TAG_CONFIG = 0x0040,
LFSR_TAG_MROOT = 0x0110,
LFSR_TAG_NAME = 0x1000,
LFSR_TAG_BRANCH = 0x1000,
LFSR_TAG_MKBRANCH = 0x1004, // in-device only
LFSR_TAG_REG = 0x1010,
LFSR_TAG_MKREG = 0x1014, // in-device only
LFSR_TAG_DIR = 0x1020,
LFSR_TAG_MKDIR = 0x1024, // in-device only
LFSR_TAG_STRUCT = 0x3000,
LFSR_TAG_INLINED = 0x3000,
LFSR_TAG_MKINLINED = 0x3004, // test only?
LFSR_TAG_BLOCK = 0x3100,
LFSR_TAG_MDIR = 0x3200,
LFSR_TAG_RMMDIR = 0x3202,
LFSR_TAG_BTREE = 0x3300,
LFSR_TAG_MKBTREE = 0x3304, // in-device only
LFSR_TAG_RMBTREE = 0x3302,
LFSR_TAG_UATTR = 0x4000,
LFSR_TAG_MKUATTR = 0x4004, // in-device only
LFSR_TAG_RMUATTR = 0x4002,
LFSR_TAG_ALT = 0x0008,
LFSR_TAG_ALTBLE = 0x0008,
LFSR_TAG_ALTRLE = 0x000a,
LFSR_TAG_ALTBGT = 0x000c,
LFSR_TAG_ALTRGT = 0x000e,
LFSR_TAG_CRC = 0x0004,
LFSR_TAG_FCRC = 0x1004,
// in-device only
LFSR_TAG_GROW = 0xf000,
LFSR_TAG_SHRINK = 0xf010,
LFSR_TAG_FROM = 0xf020,
};
#define LFSR_TAG_ALT_(color, dir, key) \
(LFSR_TAG_ALT \
| ((0x1 & (lfsr_tag_t)(color)) << 1) \
| ((0x1 & (lfsr_tag_t)(dir)) << 2) \
| ((0xfff0 & (lfsr_tag_t)(key))))
#define LFSR_TAG_ALT(color, dir, key) \
(LFSR_TAG_ALT##color##dir \
| ((0xfff0 & (lfsr_tag_t)(key))))
#define LFSR_TAG_UATTR(attr) \
(LFSR_TAG_UATTR \
| ((0xff & (lfsr_tag_t)(attr)) << 4))
#define LFSR_TAG_MKUATTR(attr) \
(LFSR_TAG_MKUATTR \
| ((0xff & (lfsr_tag_t)(attr)) << 4))
#define LFSR_TAG_RMUATTR(attr) \
(LFSR_TAG_RMUATTR \
| ((0xff & (lfsr_tag_t)(attr)) << 4))
// tag type operations
static inline lfsr_tag_t lfsr_tag_suptype(lfsr_tag_t tag) {
return tag & 0xf00f;
}
static inline uint8_t lfsr_tag_subtype(lfsr_tag_t tag) {
return (tag & 0x0ff0) >> 4;
}
static inline bool lfsr_tag_ismk(lfsr_tag_t tag) {
return tag & 0x4;
}
static inline lfsr_tag_t lfsr_tag_setmk(lfsr_tag_t tag) {
return tag | 0x4;
}
static inline lfsr_tag_t lfsr_tag_setnomk(lfsr_tag_t tag) {
return tag & ~0x4;
}
static inline bool lfsr_tag_isrm(lfsr_tag_t tag) {
return tag & 0x2;
}
static inline lfsr_tag_t lfsr_tag_setrm(lfsr_tag_t tag) {
return tag | 0x2;
}
static inline bool lfsr_tag_istrunk(lfsr_tag_t tag) {
return (tag & 0xc) != 0x4;
}
static inline bool lfsr_tag_isalt(lfsr_tag_t tag) {
return tag & 0x8;
}
static inline lfsr_tag_t lfsr_tag_next(lfsr_tag_t tag) {
return tag + 0x10;
}
// lfsr_rbyd_append specific flags
static inline bool lfsr_tag_isfound(lfsr_tag_t tag) {
return tag & 0x1;
}
static inline lfsr_tag_t lfsr_tag_setfound(lfsr_tag_t tag) {
return tag | 0x1;
}
static inline bool lfsr_tag_isupper(lfsr_tag_t tag) {
return tag & 0x4;
}
static inline bool lfsr_tag_islower(lfsr_tag_t tag) {
return !lfsr_tag_isupper(tag);
}
static inline lfsr_tag_t lfsr_tag_setupper(lfsr_tag_t tag) {
return tag | 0x4;
}
static inline bool lfsr_tag_hasdiverged(lfsr_tag_t tag) {
return tag & 0x8;
}
static inline lfsr_tag_t lfsr_tag_setdiverged(lfsr_tag_t tag) {
return tag | 0x8;
}
// alt operations
static inline bool lfsr_tag_isblack(lfsr_tag_t tag) {
return !(tag & 0x2);
}
static inline bool lfsr_tag_isred(lfsr_tag_t tag) {
return tag & 0x2;
}
static inline lfsr_tag_t lfsr_tag_setblack(lfsr_tag_t tag) {
return tag & ~0x2;
}
static inline lfsr_tag_t lfsr_tag_setred(lfsr_tag_t tag) {
return tag | 0x2;
}
static inline bool lfsr_tag_isle(lfsr_tag_t tag) {
return !(tag & 0x4);
}
static inline bool lfsr_tag_isgt(lfsr_tag_t tag) {
return tag & 0x4;
}
static inline lfsr_tag_t lfsr_tag_isparallel(lfsr_tag_t a, lfsr_tag_t b) {
return (a & 0x4) == (b & 0x4);
}
static inline lfsr_tag_t lfsr_tag_key(lfsr_tag_t tag) {
return tag & ~0xf;
}
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-0x10);
}
}
static inline void lfsr_tag_flip(lfsr_tag_t *alt, lfs_size_t *weight,
lfs_ssize_t lower, lfs_ssize_t upper) {
*alt = *alt ^ 0x4;
*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 + 0x10;
}
} else {
*lower_id += weight;
if (lower_tag) {
*lower_tag = alt + 0x10;
}
}
}
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 3-piece tag:
//
// - 16-bit type => 2 byte le16
// - 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 = lfs_fromle16_(&buf[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 & 1) != (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 & ~0x1;
*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;
// encode into an le16 and pair of leb128s
uint8_t buf[LFSR_TAG_DSIZE];
lfs_tole16_(tag, &buf[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;
} buf;
struct {
lfs_size_t size;
lfs_block_t block;
lfs_off_t off;
} disk;
} lfsr_data_t;
#define LFSR_DATA_NULL \
((lfsr_data_t){.size=0})
#define LFSR_DATA_BUF(_buffer, _size) \
((lfsr_data_t){.buf={ \
.size=_size, \
.buffer=(const void*)(_buffer)}})
#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;
}
static lfsr_data_t lfsr_data_add(lfsr_data_t data, lfs_off_t off) {
// limit our off to data range
lfs_off_t off_ = lfs_min32(off, lfsr_data_size(data));
if (lfsr_data_ondisk(data)) {
data.disk.off += off_;
data.disk.size -= off_;
} else {
data.buf.buffer += off_;
data.buf.size -= off_;
}
return data;
}
// 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 int lfsr_data_cmp(lfs_t *lfs, lfsr_data_t data,
lfs_off_t off, const void *buffer, lfs_size_t size,
int *cmp) {
// 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_;
// return early if our size doesn't match
if (hint_ < size) {
*cmp = -1;
return 0;
} else if (hint_ > size) {
*cmp = +1;
return 0;
}
if (lfsr_data_ondisk(data)) {
int err = lfsr_bd_cmp(lfs, data.disk.block, data.disk.off+off_, 0,
buffer, size,
cmp);
if (err) {
return err;
}
} else {
*cmp = memcmp(data.buf.buffer+off_, buffer, size);
}
return 0;
}
static lfs_ssize_t 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 {
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;
lfsr_data_t data;
} lfsr_attr_t;
#define LFSR_ATTR_DATA_(_id, _tag, _delta, _data) \
((const lfsr_attr_t){_id, _tag, _delta, _data})
#define LFSR_ATTR_DATA(_id, _type, _delta, _data) \
LFSR_ATTR_DATA_(_id, LFSR_TAG_##_type, _delta, _data)
#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 {
lfs_size_t size;
uint32_t crc;
} 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_ssize_t d_ = lfs_toleb128(fcrc->size, &buffer[0], 5);
if (d_ < 0) {
return d_;
}
d += d_;
lfs_tole32_(fcrc->crc, &buffer[d]);
d += 4;
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_readleb128(lfs, data, d, &fcrc->size);
if (d_ < 0) {
return d_;
}
d += d_;
d_ = lfsr_data_readle32(lfs, data, d, &fcrc->crc);
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;
}
/// 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);
/// Block allocator ///
#ifndef LFS_READONLY
static int lfs_alloc_lookahead(void *p, lfs_block_t block) {
lfs_t *lfs = (lfs_t*)p;
lfs_block_t off = ((block - lfs->free.off)
+ lfs->cfg->block_count) % lfs->cfg->block_count;
if (off < lfs->free.size) {
lfs->free.buffer[off / 32] |= 1U << (off % 32);
}
return 0;
}
#endif
// indicate allocated blocks have been committed into the filesystem, this
// is to prevent blocks from being garbage collected in the middle of a
// commit operation
static void lfs_alloc_ack(lfs_t *lfs) {
lfs->free.ack = lfs->cfg->block_count;
}
// drop the lookahead buffer, this is done during mounting and failed
// traversals in order to avoid invalid lookahead state
static void lfs_alloc_drop(lfs_t *lfs) {
lfs->free.size = 0;
lfs->free.i = 0;
lfs_alloc_ack(lfs);
}
#ifndef LFS_READONLY
static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
while (true) {
while (lfs->free.i != lfs->free.size) {
lfs_block_t off = lfs->free.i;
lfs->free.i += 1;
lfs->free.ack -= 1;
if (!(lfs->free.buffer[off / 32] & (1U << (off % 32)))) {
// found a free block
*block = (lfs->free.off + off) % lfs->cfg->block_count;
// eagerly find next off so an alloc ack can
// discredit old lookahead blocks
while (lfs->free.i != lfs->free.size &&
(lfs->free.buffer[lfs->free.i / 32]
& (1U << (lfs->free.i % 32)))) {
lfs->free.i += 1;
lfs->free.ack -= 1;
}
printf("debug: lfs_alloc: %x\n", *block);
return 0;
}
}
// check if we have looked at all blocks since last ack
if (lfs->free.ack == 0) {
LFS_ERROR("No more free space %"PRIu32,
lfs->free.i + lfs->free.off);
return LFS_ERR_NOSPC;
}
lfs->free.off = (lfs->free.off + lfs->free.size)
% lfs->cfg->block_count;
lfs->free.size = lfs_min(8*lfs->cfg->lookahead_size, lfs->free.ack);
lfs->free.i = 0;
// find mask of free blocks from tree
memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);
int err = lfs_fs_rawtraverse(lfs, lfs_alloc_lookahead, lfs, true);
if (err) {
lfs_alloc_drop(lfs);
return err;
}
}
}
#endif
/// 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, uint32_t rev) {
*rbyd = (lfsr_rbyd_t){.rev=rev, .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,
lfsr_find_t *find) {
// clear any previous state in our find
if (find) {
find->predicted_id = -1;
find->predicted_tag = 0;
find->found_id = -1;
find->found_tag = 0;
}
// read the revision count and get the crc started
uint32_t rev;
uint32_t crc = 0;
int err = lfsr_bd_readcsum(lfs, block, 0, lfs->cfg->block_size,
&rev, sizeof(uint32_t),
&crc);
if (err) {
return err;
}
rev = lfs_fromle32_(&rev);
rbyd->block = block;
rbyd->off = 0;
rbyd->rev = rev;
// 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 lower = 0;
lfs_size_t upper = 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;
if (find) {
find->found_id = find->predicted_id;
find->found_tag = find->predicted_tag;
}
}
// found a trunk of a tree?
if (lfsr_tag_istrunk(tag) && (!trunk || trunk >= off-d || wastrunk)) {
if (!wastrunk) {
// save trunk entry point
trunk_ = off-d;
// reset weights
lower = 0;
upper = 0;
wastrunk = true;
}
// derive the new 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
if (lfsr_tag_isalt(tag)) {
if (lfsr_tag_isgt(tag)) {
upper += w;
} else {
lower += w;
}
} else {
lfs_ssize_t delta = (lower+upper+w) - weight;
weight = lower+upper+w;
lfs_ssize_t id = lower+w-1;
// adjust any pending finds
if (find && find->predicted_id >= (lfs_ssize_t)lower) {
// pending find removed?
if (find->predicted_id + delta < (lfs_ssize_t)lower) {
find->predicted_id = lower-1;
find->predicted_tag = 0;
} else {
find->predicted_id += delta;
}
}
// found our find request?
if (find && lfsr_tag_suptype(tag) == LFSR_TAG_NAME) {
// compare with disk
lfs_size_t d = lfs_min(size, find->name_size);
int cmp;
int err = lfsr_bd_cmp(lfs, block, off, d,
find->name, d,
&cmp);
if (err) {
return err;
}
if (cmp == 0) {
if (size < find->name_size) {
cmp = -1;
} else if (size > find->name_size) {
cmp = +1;
}
}
// found match?
if (cmp == 0) {
find->predicted_id = id;
find->predicted_tag = tag;
// didn't find a match, but found a better insertion point
} else if (cmp < 0 && id > find->predicted_id) {
find->predicted_id = id;
find->predicted_tag = 0;
}
}
// any non-alt terminates the current trunk
wastrunk = false;
}
}
if (!lfsr_tag_isalt(tag)) {
off += size;
}
}
// no valid commits?
if (rbyd->off == 0) {
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 = lfs->cfg->block_size;
}
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_) {
// 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;
// make sure we never look up zero tags, the way we create
// unreachable tags has a hole here
tag = lfs_max16(tag, 0x10);
// 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;
// not what we're looking for?
if (id__ < id
|| (id__ == id && lfsr_tag_key(tag__) < lfsr_tag_key(tag))
|| lfsr_tag_isrm(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_data_t *data_) {
lfs_ssize_t id_;
lfsr_tag_t tag_;
int err = lfsr_rbyd_lookupnext(lfs, rbyd, id, 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
if (id_ != id || tag_ != tag) {
return LFS_ERR_NOENT;
}
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, &data);
if (err) {
return err;
}
return lfsr_data_read(lfs, data, 0, buffer, size);
}
// 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));
// never write zero tags to disk, use unr if tag contains no data
LFS_ASSERT(tag != 0);
// 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
if (lfsr_tag_setnomk(tag) == LFSR_TAG_UNR && delta == 0) {
return 0;
}
// make sure every rbyd starts with its revision count
if (rbyd->off == 0) {
uint8_t buf[sizeof(uint32_t)];
lfs_tole32_(rbyd->rev, &buf);
err = lfsr_bd_prog(lfs, rbyd->block, rbyd->off,
&buf, sizeof(uint32_t), &rbyd->crc);
if (err) {
goto failed;
}
rbyd->off += sizeof(uint32_t);
}
// 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 (lfsr_tag_ismk(tag) && 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;
// also note these tags MUST NOT be zero, due to unreachable tag holes
tag_ = 0x10;
other_tag_ = lfsr_tag_setupper(0x10);
} else if (lfsr_tag_ismk(tag) && 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 - lfs_smax32(-delta, 0);
other_id_ = id;
// also note these tags MUST NOT be zero, due to unreachable tag holes
tag_ = 0x10;
other_tag_ = lfsr_tag_setupper(0x10);
} else if (lfsr_tag_isrm(tag)) {
LFS_ASSERT(id < (lfs_ssize_t)rbyd->weight);
id_ = id - lfs_smax32(-delta, 0);
other_id_ = id;
tag_ = lfsr_tag_key(tag);
other_tag_ = lfsr_tag_setupper(lfsr_tag_key(tag) + 0x10);
} else {
LFS_ASSERT(id < (lfs_ssize_t)rbyd->weight);
id_ = id - lfs_smax32(-delta, 0);
other_id_ = id;
tag_ = lfsr_tag_key(tag);
other_tag_ = lfsr_tag_setupper(lfsr_tag_key(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_setdiverged(tag_);
other_tag_ = lfsr_tag_setdiverged(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_isupper(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:
// - preserve diverged bit (0x8)
// - preserve is upper tag (0x4)
// - set found tag (0x1)
tag_ = lfsr_tag_setfound(alt | (tag_ & 0xc));
id_ = upper_id-1;
// done?
if (!lfsr_tag_hasdiverged(tag_)
|| lfsr_tag_isfound(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_isfound(tag_));
LFS_ASSERT(!lfsr_tag_hasdiverged(tag_)
|| lfsr_tag_isfound(other_tag_));
if (lfsr_tag_hasdiverged(tag_) && lfsr_tag_islower(tag_)) {
// finished on lower path
tag_ = other_tag_;
id_ = other_id_;
branch = other_branch;
upper_id = other_upper_id;
} else if (lfsr_tag_hasdiverged(tag_) && lfsr_tag_isupper(tag_)) {
// 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
lfsr_tag_t alt = 0;
lfs_size_t weight = 0;
if (lfsr_tag_isrm(tag_)) {
// found an old removed tag, no split needed, just prune the
// removed tag
} else if (id_ < id-lfs_smax32(-delta, 0)
|| (id_ == id-lfs_smax32(-delta, 0)
&& ((lfsr_tag_ismk(tag) && delta > 0)
|| lfsr_tag_key(tag_) < lfsr_tag_key(tag)))) {
if (lfsr_tag_isrm(tag)) {
// if removed make our tag unreachable
alt = LFSR_TAG_ALT(B, GT, 0);
weight = upper_id - lower_id - 1 + delta;
upper_id -= weight;
} else {
// split less than
alt = LFSR_TAG_ALT(R, LE, tag_);
weight = id_ - lower_id;
lower_id += weight;
}
} else if (id_ > id
|| (id_ == id
&& ((lfsr_tag_ismk(tag) && delta > 0)
|| lfsr_tag_key(tag_) > lfsr_tag_key(tag)))) {
if (lfsr_tag_isrm(tag)) {
// if removed make our tag unreachable
alt = LFSR_TAG_ALT(B, GT, 0);
weight = upper_id - lower_id - 1 + delta;
upper_id -= weight;
} else {
// split greater than
alt = LFSR_TAG_ALT(R, GT, 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 something after the alts! without something between
// alts we may not be able to find the trunk of our tree
lfs_ssize_t d = lfsr_bd_progtag(lfs, rbyd->block, rbyd->off,
lfsr_tag_setnomk(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 = lfs->cfg->block_size;
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++) {
if (attrs[i].id >= start_id && (end_id < 0 || attrs[i].id < end_id)) {
int err = lfsr_rbyd_append(lfs, rbyd,
attrs[i].id-lfs_smax32(start_id, 0),
attrs[i].tag, attrs[i].delta, attrs[i].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;
}
static int lfsr_rbyd_compact(lfs_t *lfs, lfsr_rbyd_t *rbyd,
lfs_ssize_t start_id, lfs_ssize_t end_id, bool drop_vestigial,
const lfsr_rbyd_t *source) {
// optionally drop the first name in our rbyd, a so-called "vestigial"
// name, see lfsr_btree_commit for why we need to do this
lfs_ssize_t id = start_id;
lfsr_tag_t tag = (drop_vestigial ? lfsr_tag_next(LFSR_TAG_BRANCH) : 0);
// try to copy over tags
while (true) {
lfsr_data_t data;
int err = lfsr_rbyd_lookupnext(lfs, source, id, lfsr_tag_next(tag),
&id, &tag, NULL, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT || (end_id >= 0 && id >= end_id)) {
return 0;
}
// note we need to account for the missing weight of vestigial
// name tags in the following branch tag, which is why we
// calculate weight like this
lfs_size_t w = id-lfs_smax32(start_id, 0)+1 - rbyd->weight;
// append the attr
err = lfsr_rbyd_append(lfs, rbyd,
id-lfs_smax32(w-1, 0)-lfs_smax32(start_id, 0),
lfsr_tag_setmk(tag), +w, data);
if (err) {
return err;
}
}
}
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
lfsr_rbyd_t rbyd_ = *rbyd;
// make sure every rbyd starts with its revision count
if (rbyd_.off == 0) {
uint8_t buf[sizeof(uint32_t)];
lfs_tole32_(rbyd_.rev, &buf);
err = lfsr_bd_prog(lfs, rbyd_.block, rbyd_.off,
&buf, sizeof(uint32_t), &rbyd_.crc);
if (err) {
goto failed;
}
rbyd_.off += sizeof(uint32_t);
}
// 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 = lfs->cfg->block_size;
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 = {.size=lfs->cfg->prog_size, .crc=0};
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];
lfs_tole16_(LFSR_TAG_CRC | (lfs_popc(rbyd_.crc) & 1), &buf[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 & 1)) {
buf[0] ^= 0x10;
rbyd_.crc ^= 0x847609b4; // 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 = lfs->cfg->block_size;
return err;
}
// the following are mostly btree helpers, but since they operate on rbyds,
// exist in the rbyd namespace
static int lfsr_rbyd_estimate(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t start_id, lfs_size_t threshold,
lfs_size_t *lower_id_, lfs_size_t *lower_dsize_) {
// determine if a given rbyd will be within the compaction threshold (1/2)
// after compaction, note this uses a conservative estimate so the actual
// on-disk cost may be smaller
//
// returns the id/dsize where the threshold failed, this isn't that useful
// on its own, but can be used to find a good split_id with lfsr_rbyd_bisect
// TODO should we store this in lfs_t somewhere?
// assume a tighter bound on size/jump leb128 encoding if we know
// our block_size
const lfs_size_t tag_dsize = 2
+ 5
+ (lfs_nlog2(lfs->cfg->block_size)+7-1)/7;
lfs_size_t tcount = 0;
lfs_size_t dsize = 0;
lfs_size_t real_dsize = sizeof(uint32_t);
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, rbyd, id, lfsr_tag_next(tag),
&id, &tag, &w, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT) {
return true;
}
// Exhibit A. Why I really didn't want to estimate the rbyd threshold:
// TODO do we really need this tight a bound? this might be the only
// place we divide by a non-power-of-two
// keep track of alt-less tcount and dsize
//
// this is used as a heuristic for split, so the exactness matters less,
// but we need to be able to subtract tags from the result so we can't
// use the estimate with alt pointers
tcount += 1;
dsize += LFSR_TAG_DSIZE + lfsr_data_size(data);
// determine the upper-bound of our alt pointers, tag, and data
//
// fortunately the self-balancing nature of rybds give us a tight
// bound on the number of alt pointers
real_dsize
+= (2*lfs_nlog2(tcount+1)+1) * tag_dsize
+ tag_dsize
+ lfsr_data_size(data);
// exceeded our compaction threshold?
if (real_dsize > threshold) {
// TODO do these need to be conditional?
if (lower_id_) {
*lower_id_ = id+1;
}
if (lower_dsize_) {
*lower_dsize_ = dsize;
}
return false;
}
}
}
static lfs_ssize_t lfsr_rbyd_bisect(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_size_t lower_id, lfs_size_t lower_dsize) {
// find the best id to split the rbyd evenly
// TODO is this really worth it vs a simpler algorithm?
//
// here we ignore the cost of alt-pointers, and only use the tag+data cost
// as a heuristic
//
// we assume we already found an over-estimate of the split id in
// lfsr_rbyd_threshold, so we only need to work backwards through
// the rbyd to correct this over-estimate, this is a minor optimization
// but doesn't change the runtime complexity of this operation.
//
lfs_size_t lower_id_ = lower_id;
lfs_ssize_t upper_id = rbyd->weight-1;
lfs_size_t upper_dsize = 0;
while (true) {
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,
upper_id, lfsr_tag_next(tag),
&id_, &tag, &w_, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err == LFS_ERR_NOENT || id_ != upper_id) {
break;
}
// keep track of weight to iterate backwards
w += w_;
// assume worst-case encoding size
dsize += LFSR_TAG_DSIZE + lfsr_data_size(data);
}
LFS_ASSERT(w > 0);
// steal dsize from lower_dsize if we start overlapping
if ((lfs_size_t)upper_id-(w-1) < lower_id_) {
lower_id_ = upper_id-(w-1);
lower_dsize -= dsize;
}
upper_dsize += dsize;
// done when upper/lower dsizes are close to balanced
if (upper_dsize >= lower_dsize) {
break;
}
// iterate backwards
upper_id -= w;
}
// we should have _some_ ids in both children
LFS_ASSERT(lower_id_ > 0);
LFS_ASSERT(lower_id_ < rbyd->weight);
return lower_id_;
}
static int lfsr_rbyd_isdegenerate(lfs_t *lfs, const lfsr_rbyd_t *rbyd,
lfs_ssize_t cutoff) {
// 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
// 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;
}
}
}
/// Rbyd b-tree operations ///
// convenience operations
// TODO need null btrees?
#define LFSR_BTREE_NULL ((lfsr_btree_t){.weight=0x80000000})
static inline bool lfsr_btree_isinlined(const lfsr_btree_t *btree) {
return btree->weight & 0x80000000;
}
static inline bool lfsr_btree_isnull(const lfsr_btree_t *btree) {
return lfsr_btree_isinlined(btree) && btree->inlined.tag == 0;
}
static inline lfs_size_t lfsr_btree_weight(const lfsr_btree_t *btree) {
return btree->weight & 0x7fffffff;
}
static inline lfs_size_t lfsr_btree_setinlined(lfs_size_t weight) {
return weight | 0x80000000;
}
// branch on-disk encoding
// 3 leb128 + 1 crc32c => 19 bytes (worst case)
#define LFSR_BRANCH_DSIZE (5+5+5+4)
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_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_;
lfs_tole32_(branch->crc, &buffer[d]);
d += 4;
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_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_;
d_ = lfsr_data_readle32(lfs, data, d, &branch->crc);
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 *tag_, uint8_t buffer[static LFSR_BTREE_DSIZE]) {
// we shouldn't write null btrees to disk, we just don't write out btrees
// if they're null
LFS_ASSERT(!lfsr_btree_isnull(btree));
// inlined?
if (lfsr_btree_isinlined(btree)) {
*tag_ = btree->inlined.tag;
memcpy(buffer, btree->inlined.buffer, btree->inlined.size);
return btree->inlined.size;
// not inlined
} else {
*tag_ = LFSR_TAG_BTREE;
return lfsr_branch_todisk(lfs, &btree->root, 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 tag, lfs_size_t weight, lfsr_data_t data) {
// inlined?
if (tag != LFSR_TAG_BTREE) {
btree->weight = lfsr_btree_setinlined(weight);
btree->inlined.tag = tag;
lfs_ssize_t size = lfsr_data_read(lfs, data, 0,
btree->inlined.buffer, LFSR_BTREE_INLINESIZE);
if (size < 0) {
return size;
}
btree->inlined.size = size;
return size;
// not inlined
} else {
return lfsr_branch_fromdisk(lfs, &btree->root, 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_, bool validate) {
// 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->inlined.tag;
}
if (weight_) {
*weight_ = lfsr_btree_weight(btree);
}
if (data_) {
*data_ = LFSR_DATA_BUF(btree->inlined.buffer, btree->inlined.size);
}
return 0;
}
// descend down the btree looking for our bid
lfsr_rbyd_t branch = btree->root;
lfs_ssize_t rid = bid;
while (true) {
// if we're validating during our lookup, we need to fetch each branch,
// otherwise we can get away with assuming our stored block+trunk is
// correct
//
// though we assume fetched branches have already been validated, this
// generally only affects the root rbyd but note the root rbyd is the
// most heavily accessed
//
if (validate && !lfsr_rbyd_isfetched(&branch)) {
lfsr_rbyd_t branch_;
int err = lfsr_rbyd_fetch(lfs, &branch_,
branch.block, branch.trunk, NULL);
if (err) {
if (err == LFS_ERR_CORRUPT) {
LFS_ERROR("Corrupted rbyd found during btree lookup "
"(rbyd=0x%"PRIx32".%"PRIx32", "
"0x%08"PRIx32" != 0x%08"PRIx32")",
branch.block, branch.trunk,
branch_.crc, 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("Corrupted rbyd found during btree lookup "
"(rbyd=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);
branch = branch_;
}
// 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_lookupnext(lfs, &branch, rid__, LFSR_TAG_STRUCT,
NULL, &tag__, NULL, &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_, bool validate) {
return lfsr_btree_lookupnext_(lfs, btree, bid,
bid_, NULL, NULL, tag_, weight_, data_,
validate);
}
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_, bool validate) {
lfs_size_t bid_;
int err = lfsr_btree_lookupnext(lfs, btree, bid,
&bid_, tag_, weight_, data_,
validate);
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,
bool validate) {
lfsr_data_t data;
int err = lfsr_btree_lookup(lfs, btree, bid,
tag_, weight_, &data,
validate);
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->root.block == child->block
&& btree->root.trunk == child->trunk)) {
return LFS_ERR_NOENT;
}
// descend down the btree looking for our id
lfsr_rbyd_t branch = btree->root;
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_lookupnext(lfs, &branch, rid__, LFSR_TAG_STRUCT,
NULL, &tag__, NULL, &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_;
}
}
static lfs_ssize_t lfsr_btree_namelookupnext(lfs_t *lfs,
const lfsr_btree_t *btree, const char *name, lfs_size_t name_size,
lfs_size_t *bid_, lfsr_rbyd_t *rbyd_, lfs_ssize_t *rid_,
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->inlined.tag;
}
if (weight_) {
*weight_ = lfsr_btree_weight(btree);
}
if (data_) {
*data_ = LFSR_DATA_BUF(btree->inlined.buffer, btree->inlined.size);
}
return 0;
}
// descend down the btree looking for our name
lfsr_rbyd_t branch = btree->root;
lfs_ssize_t bid = 0;
lfsr_find_t find = {.name=name, .name_size=name_size};
while (true) {
// name lookup in our rbyds requires a linear search, so we might as
// well revalidate the rbyd with a fetch
lfsr_rbyd_t branch_;
int err = lfsr_rbyd_fetch(lfs, &branch_,
branch.block, branch.trunk, &find);
if (err) {
if (err == LFS_ERR_CORRUPT) {
LFS_ERROR("Corrupted rbyd found during btree lookup "
"(rbyd=0x%"PRIx32".%"PRIx32", "
"0x%08"PRIx32" != 0x%08"PRIx32")",
branch.block, branch.trunk,
branch_.crc, branch.crc);
}
return err;
}
if (branch_.crc != branch.crc) {
LFS_ERROR("Corrupted rbyd found during btree lookup "
"(rbyd=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);
branch = branch_;
// assume lowest id if no name found
//
// note this ignore any name attached to the lowest id, this is
// intentional as allowing for "vestigial" names in our blocks helps
// simplify some of the more complicated merge/split interactions
if (find.found_id < 0) {
find.found_id = 0;
}
// the find may not match exactly, but it will indicate which id we
// should follow
//
// Note that we can't reliably find the weight in fetch. If, during our
// linear search, we match an id that is later deleted, we know id-1
// should be the new id, but we don't have enough information to
// determine the new weight. So unfortunately we need an additional
// lookup to find the weight.
lfsr_tag_t tag__;
lfs_ssize_t rid__;
// 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__;
err = lfsr_rbyd_lookupnext(lfs, &branch, find.found_id, 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_lookupnext(lfs, &branch, rid__, LFSR_TAG_STRUCT,
NULL, &tag__, NULL, &data__);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
}
// found another branch
if (tag__ == LFSR_TAG_BTREE) {
// update our id
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 (rbyd_) {
*rbyd_ = branch;
}
if (rid_) {
*rid_ = rid__;
}
if (tag_) {
*tag_ = tag__;
}
if (weight_) {
*weight_ = weight__;
}
if (data_) {
*data_ = data__;
}
return 0;
}
}
}
// 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, NULL);
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, MKUNR, +rbyd->weight-pweight,
scratch_buf, d);
attr_count = 1;
} else {
attrs[0] = LFSR_ATTR(pid, UNR, +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 lower_id;
lfs_size_t lower_dsize;
// 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
int fits = lfsr_rbyd_estimate(lfs, rbyd, -1,
lfs->cfg->block_size/2,
&lower_id, &lower_dsize);
if (fits < 0) {
return fits;
}
if (!fits) {
// need to split
goto split;
}
// TODO were we doing something funky with rev?
// allocate a new rbyd
err = lfsr_rbyd_alloc(lfs, &rbyd_, rbyd->rev+1);
if (err) {
return err;
}
// try to copy over tags
//
// Because it makes a lot of the split-sensitive cross-id
// operations easier, we can end up with an occasional
// "vestigial" name tag on the first id in a block. We make
// sure to ignore these during lookup, but it would be more
// complicated then it's worth to clean these up proactively.
//
// Discarding these during compaction is easy and prevents any
// real storage cost.
err = lfsr_rbyd_compact(lfs, &rbyd_, 0, -1, true,
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, MKUNR, +rbyd->weight-pweight,
scratch_buf, d);
attr_count = 1;
} else {
attrs[0] = LFSR_ATTR(pid, UNR, +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:;
// first figure out which id we need to split around
LFS_ASSERT(lower_id > 0);
lfs_ssize_t split_id = lfsr_rbyd_bisect(lfs, rbyd,
lower_id, lower_dsize);
if (split_id < 0) {
return split_id;
}
// TODO were we doing something funky with rev?
// allocate a new rbyd
err = lfsr_rbyd_alloc(lfs, &rbyd_, rbyd->rev+1);
if (err) {
return err;
}
// allocate a sibling
lfsr_rbyd_t sibling;
err = lfsr_rbyd_alloc(lfs, &sibling, rbyd->rev+1);
if (err) {
return err;
}
// copy over tags < split_id
err = lfsr_rbyd_compact(lfs, &rbyd_, 0, split_id, true,
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, false,
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, 1);
if (err) {
return err;
}
// prepare commit to parent, tail recursing upwards
attrs[0] = LFSR_ATTR(0, MKBTREE, +rbyd_.weight,
scratch_buf1, d1);
attrs[1] = (lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? LFSR_ATTR_DATA(rbyd_.weight, MKBRANCH, +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, MKBTREE, +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, UNR, +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,
MKBRANCH, +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,
MKBTREE, +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_lookupnext(lfs, &parent, sid, LFSR_TAG_STRUCT,
NULL, &stag, NULL, &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
int fits = lfsr_rbyd_estimate(lfs, &sibling, -1,
lfs->cfg->block_size/4,
NULL, NULL);
if (fits < 0) {
return fits;
}
// don't fit? can't merge
if (!fits) {
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), lfsr_tag_setmk(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_MKUNR, -(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, MKUNR, -sweight, NULL, 0);
attrs[1] = LFSR_ATTR(pid, UNR, +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->root = *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);
btree->weight = lfsr_btree_setinlined(weight);
btree->inlined.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->inlined.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->inlined.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, 1);
if (err) {
return err;
}
// commit our entries
err = lfsr_rbyd_commit(lfs, &rbyd, LFSR_ATTRS(
LFSR_ATTR_(
0, lfsr_tag_setmk(btree->inlined.tag),
+lfsr_btree_weight(btree),
btree->inlined.buffer, btree->inlined.size),
LFSR_ATTR_DATA_(
bid, lfsr_tag_setmk(tag), +weight, data)));
if (err) {
return err;
}
btree->root = 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->root;
lfs_ssize_t rid = -1;
lfs_size_t rweight = 0;
int err = lfsr_btree_lookupnext_(lfs, btree, bid_,
NULL, &rbyd, &rid, NULL, &rweight, NULL,
false);
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, lfsr_tag_setmk(tag), +weight, data)));
if (degenerate < 0) {
return degenerate;
}
// revert to an inlined btree
if (degenerate) {
btree->weight = lfsr_btree_setinlined(weight);
btree->inlined.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->inlined.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->inlined.size = d;
}
return 0;
}
}
static int lfsr_btree_update(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);
btree->weight = lfsr_btree_setinlined(weight);
btree->inlined.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->inlined.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->inlined.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,
false);
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, UNR, +weight-rweight, NULL, 0)));
if (degenerate < 0) {
return degenerate;
}
// revert to an inlined btree
if (degenerate) {
btree->weight = lfsr_btree_setinlined(weight);
btree->inlined.tag = tag;
lfs_ssize_t d = lfsr_data_read(lfs, data, 0,
btree->inlined.buffer, LFSR_BTREE_INLINESIZE);
if (d < 0) {
return d;
}
LFS_ASSERT(d <= LFSR_BTREE_INLINESIZE);
btree->inlined.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->weight = lfsr_btree_setinlined(0);
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,
false);
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, MKUNR, -rweight, NULL, 0)));
if (degenerate < 0) {
return degenerate;
}
// revert to a null btree
if (degenerate && rweight >= rbyd.weight) {
btree->weight = lfsr_btree_setinlined(0);
// 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_lookupnext(lfs, &rbyd, sid, LFSR_TAG_STRUCT,
NULL, &stag, NULL, &sdata);
if (err) {
LFS_ASSERT(err == LFS_ERR_NOENT);
return err;
}
}
LFS_ASSERT(sweight+rweight == rbyd.weight);
btree->weight = lfsr_btree_setinlined(sweight);
btree->inlined.tag = stag;
LFS_ASSERT(lfsr_data_size(sdata) <= LFSR_BTREE_INLINESIZE);
err = lfsr_bd_read(lfs, sdata.disk.block, sdata.disk.off, 0,
btree->inlined.buffer, lfsr_data_size(sdata));
if (err) {
return err;
}
btree->inlined.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, 1);
if (err) {
return err;
}
// commit our entries
err = lfsr_rbyd_commit(lfs, &rbyd, LFSR_ATTRS(
LFSR_ATTR_DATA_(0, lfsr_tag_setmk(tag1), +weight1, data1),
(lfsr_data_size(name) > 0
? LFSR_ATTR_DATA(weight1, MKBRANCH, +weight2, name)
: LFSR_ATTR_NOOP),
(lfsr_data_size(name) > 0
? LFSR_ATTR_DATA_(weight1+weight2-1,
tag2, 0, data2)
: LFSR_ATTR_DATA_(weight1,
lfsr_tag_setmk(tag2), +weight2, data2))));
if (err) {
return err;
}
btree->root = 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,
false);
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, UNR, +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, MKBRANCH, +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,
lfsr_tag_setmk(tag2), +weight2, data2))));
if (degenerate < 0) {
return degenerate;
}
// this should never happen
LFS_ASSERT(!degenerate);
return 0;
}
}
/// Metadata pair operations ///
typedef struct lfsr_mpair {
lfs_block_t blocks[2];
} lfsr_mpair_t;
#define LFSR_MPAIR(block0, block1) ((lfsr_mpair_t){.blocks={block0, block1}})
static inline bool lfsr_mpair_eq(lfsr_mpair_t a, lfsr_mpair_t b) {
// allow either order
return (a.blocks[0] == b.blocks[0] && a.blocks[1] == b.blocks[1])
|| (a.blocks[0] == b.blocks[1] && a.blocks[1] == b.blocks[0]);
}
// 2 leb128 => 10 bytes (worst case)
#define LFSR_MPAIR_DSIZE (5+5)
static lfs_ssize_t lfsr_mpair_todisk(lfs_t *lfs, lfsr_mpair_t mpair,
uint8_t buffer[static LFSR_MPAIR_DSIZE]) {
(void)lfs;
lfs_ssize_t d = 0;
for (int i = 0; i < 2; i++) {
lfs_ssize_t d_ = lfs_toleb128(mpair.blocks[i], &buffer[d], 5);
if (d_ < 0) {
return d_;
}
d += d_;
}
return d;
}
// TODO should our fromdisk functions accept an lfsr_data_t?
static lfs_ssize_t lfsr_mpair_fromdisk(lfs_t *lfs, lfsr_mpair_t *mpair,
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, &mpair->blocks[i]);
if (d_ < 0) {
return d_;
}
d += d_;
}
return d;
}
static inline lfsr_mpair_t lfsr_mdir_mpair(const lfsr_mdir_t *mdir) {
return LFSR_MPAIR(mdir->rbyd.block, mdir->other_block);
}
static inline lfs_size_t lfsr_mdir_weight(const lfsr_mdir_t *mdir) {
return mdir->rbyd.weight;
}
static int lfsr_mdir_alloc(lfs_t *lfs, lfsr_mdir_t *mdir, lfs_ssize_t mid) {
// allocate two blocks
lfs_block_t blocks[2];
for (int i = 0; i < 2; i++) {
int err = lfs_alloc(lfs, &blocks[i]);
if (err) {
return err;
}
}
// rather than performing an unecessary erase, treat the current contents
// of the other block as a valid revision count
uint32_t rev;
int err = lfsr_bd_read(lfs, blocks[1], 0, 0, &rev, sizeof(uint32_t));
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// note we can allow blocks that report corrupt here, with the assumption
// that all future reads will also return corrupt, this can happen if
// the underlying block device uses ECC that may be invalid when
// uninitialized
if (err == LFS_ERR_CORRUPT) {
rev = 0;
}
// TODO align to block_cycles
// setup mdir struct
mdir->mid = mid;
mdir->other_block = blocks[0];
mdir->rbyd.weight = 0;
mdir->rbyd.block = blocks[1];
// mark mdir as needing compaction
mdir->rbyd.off = lfs->cfg->block_size;
mdir->rbyd.trunk = 0;
mdir->rbyd.rev = rev;
return 0;
}
static int lfsr_mdir_fetch(lfs_t *lfs, lfsr_mdir_t *mdir,
lfs_ssize_t mid, lfsr_mpair_t mpair,
lfsr_find_t *find) {
// 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, mpair.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(&mpair.blocks[0], &mpair.blocks[1]);
lfs_swap32(&revs[0], &revs[1]);
}
}
// try to fetch rbyds in the order of most recent to least recent
for (int i = 0; i < 2; i++) {
int err = lfsr_rbyd_fetch(lfs, &mdir->rbyd, mpair.blocks[0], 0, find);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
if (!err) {
mdir->mid = mid;
// keep track of other block for compactions
mdir->other_block = mpair.blocks[1];
return 0;
}
lfs_swap32(&mpair.blocks[0], &mpair.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_, lfs_size_t *weight_,
lfsr_data_t *data_) {
return lfsr_rbyd_lookupnext(lfs, &mdir->rbyd, id, tag,
id_, tag_, weight_, data_);
}
static int lfsr_mdir_lookup(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfs_ssize_t id, lfsr_tag_t tag,
lfsr_data_t *data_) {
return lfsr_rbyd_lookup(lfs, &mdir->rbyd, id, 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->rbyd, id, tag, buffer, size);
}
// mtree is the core tree of mdirs in littlefs
static inline int lfsr_mtree_isinlined(lfs_t *lfs) {
return lfsr_btree_weight(&lfs->mtree) == 0;
}
static inline lfs_ssize_t lfsr_mtree_weight(lfs_t *lfs) {
return lfsr_btree_weight(&lfs->mtree);
}
static int lfsr_mtree_lookup(lfs_t *lfs, lfs_ssize_t mid, lfsr_mdir_t *mdir_) {
// TODO should we really allow -1=>mroot lookup?
LFS_ASSERT(mid >= -1);
LFS_ASSERT(mid < lfsr_mtree_weight(lfs));
// looking up mroot?
if (mid < 0) {
*mdir_ = lfs->mroot;
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,
&tag, NULL, &data, false);
if (err) {
return err;
}
LFS_ASSERT(tag == LFSR_TAG_MDIR);
// decode mpair
lfsr_mpair_t mpair;
lfs_ssize_t d = lfsr_mpair_fromdisk(lfs, &mpair, data);
if (d < 0) {
return d;
}
// fetch mdir
return lfsr_mdir_fetch(lfs, mdir_, mid, mpair, NULL);
}
}
// TODO how much of this code can we share with btree_commit?
// TODO share commit?
// TODO share split?
// TODO would be awfully convenient if c supported multiple returns
static int lfsr_mdir_commit(lfs_t *lfs, lfsr_mdir_t *mdir, lfs_ssize_t *rid,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// // scratch space for unrolled tail recursion
// uint8_t recurse_buf[LFSR_BTREE_DSIZE];
// lfsr_attr_t recurse_attrs[3];
// TODO need both dirty_mtree and uninlining?
bool dirty_mtree = false;
// TODO this can be done better, we shouldn't need all these different flags
bool uninlined = false;
while (true) {
// try to commit
lfsr_mdir_t mdir_ = *mdir;
int err = lfsr_rbyd_appendall(lfs, &mdir_.rbyd, -1, -1,
attrs, attr_count);
if (err && err != LFS_ERR_RANGE) {
//TODO should we also move if there is corruption here?
return err;
}
if (err) {
goto compact;
}
// append our mtree?
if (mdir->mid == -1 && dirty_mtree) {
// TODO hm, this is messy
if (lfsr_btree_isnull(&lfs->mtree)) {
err = lfsr_rbyd_appendall(lfs, &mdir_.rbyd, -1, -1, LFSR_ATTRS(
LFSR_ATTR(-1, RMMDIR, 0, NULL, 0),
LFSR_ATTR(-1, RMBTREE, 0, NULL, 0)));
if (err && err != LFS_ERR_RANGE) {
//TODO should we also move if there is corruption here?
return err;
}
if (err) {
goto compact;
}
} else {
lfsr_tag_t tag;
uint8_t buf[LFSR_BTREE_DSIZE];
lfs_ssize_t d = lfsr_btree_todisk(lfs, &lfs->mtree, &tag, buf);
if (d < 0) {
return d;
}
// TODO yeah we're going to need a wide-rm
err = lfsr_rbyd_appendall(lfs, &mdir_.rbyd, -1, -1, LFSR_ATTRS(
LFSR_ATTR(-1, RMMDIR, 0, NULL, 0),
LFSR_ATTR(-1, RMBTREE, 0, NULL, 0),
LFSR_ATTR_(-1, tag, 0, buf, d)));
if (err && err != LFS_ERR_RANGE) {
//TODO should we also move if there is corruption here?
return err;
}
if (err) {
goto compact;
}
}
}
if (mdir->mid >= 0 && mdir_.rbyd.weight == 0) {
// if our weight goes to zero, drop our mdir
lfs_cache_zero(lfs, &lfs->pcache);
LFS_DEBUG("Dropping mdir 0x{%"PRIx32",%"PRIx32"}",
mdir_.rbyd.block, mdir_.other_block);
// remove from mtree
err = lfsr_btree_pop(lfs, &lfs->mtree, mdir->mid);
if (err) {
return err;
}
// update our mdir, prepare mroot
mdir_.mid = -3;
*mdir = mdir_;
mdir = &lfs->mroot;
// TODO synchronize open mdirs?
// TODO wait where do we synchronize open mdirs that makes sense
// if we fail after this point?
// mark mtree as dirty and tail recurse to write it and any pending
// superattrs to the mroot
dirty_mtree = true;
attr_count = 0;
continue;
} else {
// finalize commit
err = lfsr_rbyd_commit(lfs, &mdir_.rbyd, NULL, 0);
if (err && err != LFS_ERR_RANGE) {
//TODO should we also move if there is corruption here?
return err;
}
if (err) {
goto compact;
}
// update our mdir
*mdir = mdir_;
// TODO synchronize open mdirs?
// synchronize mroot
if (mdir->mid == -1 && mdir != &lfs->mroot) {
lfs->mroot = *mdir;
}
// successful commit
break;
}
compact:;
// can't commit, try to compact
// TODO splits
// TODO relocations
// normally the new mdir is just the flipped version of our
// current mdir
mdir_ = *mdir;
bool uninlining = false;
lfs_size_t lower_id;
lfs_size_t lower_dsize;
// mroots without inlined mdirs must fit, skip the check for
// compaction threshold in this case, we'll error in lfsr_rbyd_append
// if we don't fit
if (!(mdir->mid < 0 && (!lfsr_mtree_isinlined(lfs) || uninlined))) {
// check if we're within our compaction threshold, otherwise we
// need to split
int fits = lfsr_rbyd_estimate(lfs, &mdir->rbyd, -1,
lfs->cfg->block_size/2,
&lower_id, &lower_dsize);
if (fits < 0) {
return fits;
}
if (!fits) {
// are we inlined into the mroot? we need to uninline
// before we split, and it's possible uninlining makes the mdir
// small enough that we don't even need to split
if (lfsr_mtree_isinlined(lfs)) {
uninlining = true;
// do we still need to split?
//
// note init_id was changed to 0 here
fits = lfsr_rbyd_estimate(lfs, &mdir->rbyd, 0,
lfs->cfg->block_size/2,
&lower_id, &lower_dsize);
if (fits < 0) {
return fits;
}
}
if (!fits) {
// needs to split
goto split;
}
if (uninlining) {
// allocate a new mdir for uninlining
err = lfsr_mdir_alloc(lfs, &mdir_, 0);
if (err) {
return err;
}
LFS_DEBUG("Uninlining mdir 0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}"
", 0x{%"PRIx32",%"PRIx32"}",
mdir->rbyd.block, mdir->other_block,
mdir->rbyd.block, mdir->other_block,
mdir_.rbyd.block, mdir_.other_block);
}
}
}
// swap our rbyds
lfs_swap32(&mdir_.rbyd.block, &mdir_.other_block);
// update our revision count
// TODO rev things
mdir_.rbyd.rev += 1;
mdir_.rbyd.off = 0;
mdir_.rbyd.trunk = 0;
mdir_.rbyd.weight = 0;
mdir_.rbyd.crc = 0;
// erase, preparing for compact
err = lfsr_bd_erase(lfs, mdir_.rbyd.block);
if (err) {
return err;
}
// try to copy over tags
//
// take care to skip superattrs (id=-1) if we're uninlining
//
// if we don't have inlined mdirs, then we shouldn't have any
// ids>=0 in the mroot, this check is necessary as a part
// of uninlining, and it simplifies things to do this on every
// compact of the mroot
//
// note that unlining only triggers on compact, so we should never
// end up id>=0 outside of a compact
//
err = lfsr_rbyd_compact(lfs, &mdir_.rbyd,
(uninlining ? 0 : -1),
(uninlined ? 0 : -1),
false,
&mdir->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
//
// take care to skip superattrs (id=-1) if we're uninlining, or only
// allow superattrs if we've uninlined and are now committing to our
// mroot
err = lfsr_rbyd_appendall(lfs, &mdir_.rbyd,
(uninlining ? 0 : -1),
(uninlined ? 0 : -1),
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// append our mtree?
if (mdir->mid == -1 && dirty_mtree) {
// TODO hm, this is messy
if (lfsr_btree_isnull(&lfs->mtree)) {
err = lfsr_rbyd_appendall(lfs, &mdir_.rbyd, -1, -1, LFSR_ATTRS(
LFSR_ATTR(-1, RMMDIR, 0, NULL, 0),
LFSR_ATTR(-1, RMBTREE, 0, NULL, 0)));
if (err && err != LFS_ERR_RANGE) {
//TODO should we also move if there is corruption here?
return err;
}
if (err) {
goto compact;
}
} else {
lfsr_tag_t tag;
uint8_t buf[LFSR_BTREE_DSIZE];
lfs_ssize_t d = lfsr_btree_todisk(lfs, &lfs->mtree, &tag, buf);
if (d < 0) {
return d;
}
// TODO yeah we're going to need a wide-rm
err = lfsr_rbyd_appendall(lfs, &mdir_.rbyd, -1, -1, LFSR_ATTRS(
LFSR_ATTR(-1, RMMDIR, 0, NULL, 0),
LFSR_ATTR(-1, RMBTREE, 0, NULL, 0),
LFSR_ATTR_(-1, tag, 0, buf, d)));
if (err && err != LFS_ERR_RANGE) {
//TODO should we also move if there is corruption here?
return err;
}
if (err) {
goto compact;
}
}
}
// TODO the number of conditions here feels like a mess, it would be
// nice if this could be cleaned up
if (mdir_.mid >= 0 && mdir_.rbyd.weight == 0) {
// if our weight goes to zero, drop our mdir
lfs_cache_zero(lfs, &lfs->pcache);
LFS_DEBUG("Dropping mdir 0x{%"PRIx32",%"PRIx32"}",
mdir_.rbyd.block, mdir_.other_block);
// weird case, going to zero while uninlining
//
// we need to commit our superattrs to the mroot, but that's it
if (!uninlining) {
// remove from mtree
err = lfsr_btree_pop(lfs, &lfs->mtree, mdir_.mid);
if (err) {
return err;
}
// update our mdir, prepare mroot
mdir_.mid = -3;
*mdir = mdir_;
mdir = &lfs->mroot;
}
// TODO synchronize open mdirs?
// TODO wait where do we synchronize open mdirs that makes sense
// if we fail after this point?
// TODO do we need to mark mtree as dirty if we were uninlining?
//
// mark mtree as dirty and tail recurse to write it and any
// pending superattrs to the mroot
dirty_mtree = true;
if (!uninlining) {
attr_count = 0;
} else {
uninlined = true;
}
continue;
} else {
// finalize commit
err = lfsr_rbyd_commit(lfs, &mdir_.rbyd, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
// TODO maybe mdir->mid != mdir_.mid can be used as uninlining?
if (!uninlining) {
// update our mdir
*mdir = mdir_;
// TODO deduplicate mdir synchronization?
// TODO synchronize open mdirs?
// synchronize mroot
if (mdir->mid == -1 && mdir != &lfs->mroot) {
lfs->mroot = *mdir;
}
break;
} else {
// update our mdir, prepare mroot
if (*rid < 0) {
// wait to update mdir after supdermdir update
} else {
*mdir = mdir_;
mdir = &lfs->mroot;
}
// TODO synchronize open mdirs?
// TODO wait where do we synchronize open mdirs that makes sense
// if we fail after this point?
// update our mtree
uint8_t buf[LFSR_MPAIR_DSIZE];
lfs_ssize_t d = lfsr_mpair_todisk(lfs, lfsr_mdir_mpair(&mdir_),
buf);
if (d < 0) {
return d;
}
err = lfsr_btree_push(lfs, &lfs->mtree, 0, LFSR_TAG_MDIR, 1,
LFSR_DATA_BUF(buf, d));
if (err) {
return err;
}
// mark mtree as dirty and tail recurse to write it and any
// pending superattrs to the mroot
dirty_mtree = true;
uninlined = true;
continue;
}
}
split:;
// didn't fit, split mdir
// note that we should never have an mtree update here
LFS_ASSERT(!dirty_mtree);
// first figure out which id we need to split around
LFS_ASSERT(lower_id > 0);
lfs_ssize_t split_id = lfsr_rbyd_bisect(lfs, &mdir->rbyd,
lower_id, lower_dsize);
if (split_id < 0) {
return split_id;
}
// allocate a new mdir
err = lfsr_mdir_alloc(lfs, &mdir_, (uninlining ? 0 : mdir->mid)+0);
if (err) {
return err;
}
// TODO shouldn't lfsr_mdir_alloc do all this?
// swap our rbyds
lfs_swap32(&mdir_.rbyd.block, &mdir_.other_block);
// update our revision count
// TODO rev things
mdir_.rbyd.rev += 1;
mdir_.rbyd.off = 0;
mdir_.rbyd.trunk = 0;
mdir_.rbyd.weight = 0;
mdir_.rbyd.crc = 0;
// erase, preparing for compact
err = lfsr_bd_erase(lfs, mdir_.rbyd.block);
if (err) {
return err;
}
// allocate a sibling
lfsr_mdir_t sibling;
err = lfsr_mdir_alloc(lfs, &sibling, (uninlining ? 0 : mdir->mid)+1);
if (err) {
return err;
}
// TODO shouldn't lfsr_mdir_alloc do all this?
// swap our rbyds
lfs_swap32(&sibling.rbyd.block, &sibling.other_block);
// update our revision count
// TODO rev things
sibling.rbyd.rev += 1;
sibling.rbyd.off = 0;
sibling.rbyd.trunk = 0;
sibling.rbyd.weight = 0;
sibling.rbyd.crc = 0;
// erase, preparing for compact
err = lfsr_bd_erase(lfs, sibling.rbyd.block);
if (err) {
return err;
}
if (uninlining) {
LFS_DEBUG("Uninlining mdir 0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}"
", 0x{%"PRIx32",%"PRIx32"}"
", 0x{%"PRIx32",%"PRIx32"}",
mdir->rbyd.block, mdir->other_block,
mdir->rbyd.block, mdir->other_block,
mdir_.rbyd.block, mdir_.other_block,
sibling.rbyd.block, sibling.other_block);
} else {
LFS_DEBUG("Splitting mdir 0x{%"PRIx32",%"PRIx32"} "
"-> 0x{%"PRIx32",%"PRIx32"}"
", 0x{%"PRIx32",%"PRIx32"}",
mdir->rbyd.block, mdir->other_block,
mdir_.rbyd.block, mdir_.other_block,
sibling.rbyd.block, sibling.other_block);
}
// copy over tags < split_id
//
// take care to skip superattrs (id=-1) if we're uninlining
err = lfsr_rbyd_compact(lfs, &mdir_.rbyd,
(uninlining ? 0 : -1), split_id, false,
&mdir->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
//
// take care to skip superattrs (id=-1) if we're uninlining
err = lfsr_rbyd_appendall(lfs, &mdir_.rbyd,
(uninlining ? 0 : -1), split_id,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
if (mdir_.rbyd.weight == 0) {
// if our weight goes to zero, drop our mdir
lfs_cache_zero(lfs, &lfs->pcache);
} else {
// finalize commit
err = lfsr_rbyd_commit(lfs, &mdir_.rbyd, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
// copy over tags >= split_id
err = lfsr_rbyd_compact(lfs, &sibling.rbyd, split_id, -1, false,
&mdir->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.rbyd, split_id, -1,
attrs, attr_count);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
if (sibling.rbyd.weight == 0) {
// if our weight goes to zero, drop our mdir
lfs_cache_zero(lfs, &lfs->pcache);
} else {
// finalize commit
err = lfsr_rbyd_commit(lfs, &sibling.rbyd, NULL, 0);
if (err) {
LFS_ASSERT(err != LFS_ERR_RANGE);
return err;
}
}
if (mdir_.rbyd.weight > 0 && sibling.rbyd.weight > 0) {
// 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.rbyd, 0, LFSR_TAG_NAME,
NULL, &stag, NULL, &sdata);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// update our mdir, prepare mroot
if (uninlining && *rid < 0) {
// wait to update mdir after supdermdir update
} else if (*rid < split_id) {
*mdir = mdir_;
mdir = &lfs->mroot;
} else if (*rid >= split_id) {
*mdir = sibling;
*rid -= split_id;
mdir = &lfs->mroot;
}
// TODO synchronize open mdirs?
// TODO wait where do we synchronize open mdirs that makes sense
// if we fail after this point?
// update our mtree
if (uninlining) {
// TODO do we really need an explicit push when creating a new,
// 2-sized btree?
err = lfsr_btree_push(lfs, &lfs->mtree, 0, LFSR_TAG_MDIR, 1,
LFSR_DATA_NULL);
if (err) {
return err;
}
}
uint8_t buf1[LFSR_MPAIR_DSIZE];
lfs_ssize_t d1 = lfsr_mpair_todisk(lfs, lfsr_mdir_mpair(&mdir_),
buf1);
if (d1 < 0) {
return d1;
}
uint8_t buf2[LFSR_MPAIR_DSIZE];
lfs_ssize_t d2 = lfsr_mpair_todisk(lfs, lfsr_mdir_mpair(&sibling),
buf2);
if (d2 < 0) {
return d2;
}
err = lfsr_btree_split(lfs, &lfs->mtree, mdir_.mid,
(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;
}
// mark mtree as dirty and tail recurse to write it to the mroot
dirty_mtree = true;
// only include superattrs if we're uninlining
if (!uninlining) {
attr_count = 0;
} else {
uninlined = true;
}
continue;
// weird case, one sibling went to zero while splitt
} else if (mdir_.rbyd.weight > 0 || sibling.rbyd.weight > 0) {
// set mdir_ to whichever sibling has weight still
if (mdir_.rbyd.weight == 0) {
LFS_DEBUG("Dropping mdir 0x{%"PRIx32",%"PRIx32"}",
mdir_.rbyd.block, mdir_.other_block);
sibling.mid -= 1;
mdir_ = sibling;
} else {
LFS_DEBUG("Dropping mdir 0x{%"PRIx32",%"PRIx32"}",
sibling.rbyd.block, sibling.other_block);
}
// TODO maybe mdir->mid != mdir_.mid can be used as uninlining?
if (!uninlining) {
// update our mdir
*mdir = mdir_;
// TODO deduplicate mdir synchronization?
// TODO synchronize open mdirs?
// synchronize mroot
if (mdir->mid == -1 && mdir != &lfs->mroot) {
lfs->mroot = *mdir;
}
// update our mtree
uint8_t buf[LFSR_MPAIR_DSIZE];
lfs_ssize_t d = lfsr_mpair_todisk(lfs, lfsr_mdir_mpair(&mdir_),
buf);
if (d < 0) {
return d;
}
err = lfsr_btree_update(lfs, &lfs->mtree,
mdir->mid, LFSR_TAG_MDIR, 1,
LFSR_DATA_BUF(buf, d));
if (err) {
return err;
}
// mark mtree as dirty and tail recurse to write it and any
// pending superattrs to the mroot
dirty_mtree = true;
attr_count = 0;
continue;
} else {
// TODO how the heck does rid interact with mdir splits
// + lazy attrs + mdir drops, this seems hard!
// update our mdir, prepare mroot
if (*rid < 0) {
// wait to update mdir after supdermdir update
} else {
*mdir = mdir_;
mdir = &lfs->mroot;
}
// TODO synchronize open mdirs?
// TODO wait where do we synchronize open mdirs that makes sense
// if we fail after this point?
// update our mtree
uint8_t buf[LFSR_MPAIR_DSIZE];
lfs_ssize_t d = lfsr_mpair_todisk(lfs, lfsr_mdir_mpair(&mdir_),
buf);
if (d < 0) {
return d;
}
err = lfsr_btree_push(lfs, &lfs->mtree, 0, LFSR_TAG_MDIR, 1,
LFSR_DATA_BUF(buf, d));
if (err) {
return err;
}
// mark mtree as dirty and tail recurse to write it and any
// pending superattrs to the mroot
dirty_mtree = true;
uninlined = true;
continue;
}
// weird case, both siblings went to zero, so this split actually ends
// up dropping both mdirs
} else {
LFS_DEBUG("Dropping mdir 0x{%"PRIx32",%"PRIx32"}",
mdir_.rbyd.block, mdir_.other_block);
LFS_DEBUG("Dropping mdir 0x{%"PRIx32",%"PRIx32"}",
sibling.rbyd.block, sibling.other_block);
// even weirder this can happen while uninlining
if (!uninlining) {
// remove from mtree
err = lfsr_btree_pop(lfs, &lfs->mtree, mdir->mid);
if (err) {
return err;
}
// update our mdir, prepare mroot
mdir_.mid = -3;
*mdir = mdir_;
mdir = &lfs->mroot;
}
// TODO synchronize open mdirs?
// TODO wait where do we synchronize open mdirs that makes sense
// if we fail after this point?
// TODO do we need to mark mtree as dirty if we were uninlining?
//
// mark mtree as dirty and tail recurse to write it and any
// pending superattrs to the mroot
dirty_mtree = true;
if (!uninlining) {
attr_count = 0;
} else {
uninlined = true;
}
continue;
}
}
// done
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)
// - 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)
// => 30 bytes total
//
#define LFSR_CONFIG_DSIZE (1+1+1+1+5+5+1+5+5+5)
static lfs_ssize_t lfsr_superconfig_todisk(lfs_t *lfs,
uint8_t buffer[static LFSR_CONFIG_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 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) {
// scan for the first non-fake superblock
lfsr_mpair_t mpair = LFSR_MPAIR(0, 1);
lfsr_mdir_t mdir;
// detect cycles using Brent's algorithm
lfsr_mpair_t tortoise = LFSR_MPAIR(-1, -1);
lfs_size_t tortoise_i = 1;
lfs_size_t tortoise_period = 1;
while (true) {
// TODO detect cycles with Brent's algorithm
// found a cycle?
if (lfsr_mpair_eq(mpair, tortoise)) {
LFS_WARN("Cycle detected in superblocks");
return LFS_ERR_CORRUPT;
}
if (tortoise_i == tortoise_period) {
tortoise = mpair;
tortoise_i = 0;
tortoise_period *= 2;
}
tortoise_i += 1;
// fetch next possible superblock
int err = lfsr_mdir_fetch(lfs, &mdir, -1, mpair, NULL);
if (err) {
LFS_ERROR("No littlefs superblock found");
// treat corrupt errors as invalid littlefs images
if (err == LFS_ERR_CORRUPT) {
return LFS_ERR_INVAL;
}
return err;
}
// has magic string?
lfsr_data_t data;
err = lfsr_mdir_lookup(lfs, &mdir, -1, LFSR_TAG_MAGIC, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT) {
int cmp;
err = lfsr_data_cmp(lfs, data, 0, "littlefs", 8, &cmp);
if (err) {
return err;
}
// treat corrupted magic as no magic
if (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_CONFIG, &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 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;
}
}
// lookup mroot
//
// if we have a mroot, this is actually a fake superblock and
// we need to parse the next superblock in the chain
err = lfsr_mdir_lookup(lfs, &mdir, -1, LFSR_TAG_MROOT, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// no more mroots means we found our real superblock
if (err == LFS_ERR_NOENT) {
break;
}
lfs_ssize_t d = lfsr_mpair_fromdisk(lfs, &mpair, data);
if (d < 0) {
return d;
}
}
// do we have an mtree? this could be either a single mdir or a btree
// of mdirs
lfs_ssize_t id;
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_mdir_lookupnext(lfs, &mdir, -1, LFSR_TAG_STRUCT,
&id, &tag, NULL, &data);
if (err && err != LFS_ERR_NOENT) {
return err;
}
if (err != LFS_ERR_NOENT
&& id == -1
&& lfsr_tag_suptype(tag) == LFSR_TAG_STRUCT) {
if (tag != LFSR_TAG_MDIR && tag != LFSR_TAG_BTREE) {
LFS_ERROR("Weird superstruct? 0x%"PRIx32, tag);
return LFS_ERR_CORRUPT;
}
lfs_ssize_t d = lfsr_btree_fromdisk(lfs, &lfs->mtree, tag, 1, data);
if (d < 0) {
return d;
}
} else {
// TODO null?
lfs->mtree = LFSR_BTREE_NULL;
}
lfs->mroot = mdir;
return 0;
}
static int lfsr_formatinited(lfs_t *lfs) {
uint8_t buf[LFSR_CONFIG_DSIZE];
lfs_ssize_t d = lfsr_superconfig_todisk(lfs, buf);
if (d < 0) {
return d;
}
for (int i = 0; i < 2; i++) {
// write superblock to both rbyds in the root mroot to hopefully
// avoid mounting an older filesystem on disk
lfsr_rbyd_t rbyd = {.block=i, .rev=i+1, .off=0, .trunk=0};
int err = lfsr_bd_erase(lfs, rbyd.block);
if (err) {
return err;
}
err = lfsr_rbyd_commit(lfs, &rbyd, LFSR_ATTRS(
LFSR_ATTR(-1, MAGIC, 0, "littlefs", 8),
LFSR_ATTR(-1, CONFIG, 0, buf, d)));
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;
}
// TODO this is a big hack to scaffold things until we have a working
// block allocator
//
// 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 = 2;
lfs_alloc_ack(lfs);
err = lfsr_mountinited(lfs);
if (err) {
// make sure we clean up on error
lfs_deinit(lfs);
return err;
}
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;
}
// TODO this is a big hack to scaffold things until we have a working
// block allocator
//
// 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 = 2;
lfs_alloc_ack(lfs);
err = lfsr_formatinited(lfs);
if (err) {
// make sure we clean up on error
lfs_deinit(lfs);
return err;
}
return lfs_deinit(lfs);
}
/// 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, must be multiple of 64-bits, 32-bit aligned
LFS_ASSERT(lfs->cfg->lookahead_size > 0);
LFS_ASSERT(lfs->cfg->lookahead_size % 8 == 0 &&
(uintptr_t)lfs->cfg->lookahead_buffer % 4 == 0);
if (lfs->cfg->lookahead_buffer) {
lfs->free.buffer = lfs->cfg->lookahead_buffer;
} else {
lfs->free.buffer = lfs_malloc(lfs->cfg->lookahead_size);
if (!lfs->free.buffer) {
err = LFS_ERR_NOMEM;
goto cleanup;
}
}
// 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
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->free.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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