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5eeeb9d6ac
third_party_littlefs/lfs.c
Christopher Haster 5eeeb9d6ac Revisited some generic concepts, callbacks, and some reorganization 
- Callbacks for get/match, this does have a code cost, but allows more
  code reuse, which almost balances out the code cost, but also reduces
  maintenance and increased flexibility. Also callbacks may be able to
  be gc-ed in some cases.
- Consistent struct vs _t usage, _t for external-facing struct that
  shouldn't be messed with outside the library. structs for external and
  internal structs where anyone with access is allowed to modify.
- Reorganized several high-level function groups
- Inlined structures that didn't need separate definitions in header
2018-10-18 10:00:49 -05:00

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/*
* The little filesystem
*
* Copyright (c) 2017 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "lfs.h"
#include "lfs_util.h"
/// 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 = 0xffffffff;
}
static inline void lfs_cache_zero(lfs_t *lfs, lfs_cache_t *pcache) {
// zero to avoid information leak
memset(pcache->buffer, 0xff, lfs->cfg->prog_size);
pcache->block = 0xffffffff;
}
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;
LFS_ASSERT(block != 0xffffffff);
if (off+size > lfs->cfg->block_size) {
return LFS_ERR_CORRUPT;
}
while (size > 0) {
if (pcache && block == pcache->block &&
off >= pcache->off &&
off < pcache->off + pcache->size) {
// is already in pcache?
lfs_size_t diff = lfs_min(size, pcache->size - (off-pcache->off));
memcpy(data, &pcache->buffer[off-pcache->off], diff);
data += diff;
off += diff;
size -= diff;
continue;
}
if (block == rcache->block &&
off >= rcache->off &&
off < rcache->off + rcache->size) {
// is already in rcache?
lfs_size_t diff = lfs_min(size, rcache->size - (off-rcache->off));
if (pcache && block == pcache->block) {
diff = lfs_min(diff, pcache->off - off);
}
memcpy(data, &rcache->buffer[off-rcache->off], diff);
data += diff;
off += diff;
size -= diff;
continue;
}
if (size >= hint && off % lfs->cfg->read_size == 0 &&
size >= lfs->cfg->read_size) {
// bypass cache?
lfs_size_t diff = size - (size % lfs->cfg->read_size);
int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
if (err) {
return err;
}
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->prog_size);
rcache->size = lfs_min(lfs_min(
lfs_alignup(off+hint, lfs->cfg->prog_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);
if (err) {
return err;
}
}
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;
for (lfs_off_t i = 0; i < size; i++) {
uint8_t dat;
int err = lfs_bd_read(lfs,
pcache, rcache, hint-i,
block, off+i, &dat, 1);
if (err) {
return err;
}
if (dat != data[i]) {
return false;
}
}
return true;
}
static int lfs_bd_flush(lfs_t *lfs,
lfs_cache_t *pcache, lfs_cache_t *rcache, bool validate) {
if (pcache->block != 0xffffffff && pcache->block != 0xfffffffe) {
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);
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) {
return LFS_ERR_CORRUPT;
}
}
lfs_cache_zero(lfs, pcache);
}
return 0;
}
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;
}
return lfs->cfg->sync(lfs->cfg);
}
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 != 0xffffffff);
LFS_ASSERT(off + size <= lfs->cfg->block_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 = 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 == 0xffffffff);
// 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;
}
static int lfs_bd_erase(lfs_t *lfs, lfs_block_t block) {
LFS_ASSERT(block < lfs->cfg->block_count);
return lfs->cfg->erase(lfs->cfg, 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] == 0xffffffff || pair[1] == 0xffffffff;
}
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_sync(
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]);
}
static inline void lfs_pair_tole32(lfs_block_t pair[2]) {
pair[0] = lfs_tole32(pair[0]);
pair[1] = lfs_tole32(pair[1]);
}
// 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) << 22) | ((lfs_tag_t)(id) << 12) | (lfs_tag_t)(size))
static inline bool lfs_tag_isvalid(lfs_tag_t tag) {
return !(tag & 0x80000000);
}
static inline bool lfs_tag_isuser(lfs_tag_t tag) {
return (tag & 0x40000000);
}
static inline bool lfs_tag_isdelete(lfs_tag_t tag) {
return (tag & 0x00000fff) == 0xfff;
}
static inline uint16_t lfs_tag_type(lfs_tag_t tag) {
return (tag & 0x7fc00000) >> 22;
}
static inline uint16_t lfs_tag_subtype(lfs_tag_t tag) {
return ((tag & 0x7c000000) >> 26) << 4;
}
static inline uint16_t lfs_tag_id(lfs_tag_t tag) {
return (tag & 0x003ff000) >> 12;
}
static inline lfs_size_t lfs_tag_size(lfs_tag_t tag) {
return tag & 0x00000fff;
}
static inline lfs_size_t lfs_tag_dsize(lfs_tag_t tag) {
return sizeof(tag) + lfs_tag_size(tag + lfs_tag_isdelete(tag));
}
// operations on attributes in attribute lists
struct lfs_mattr {
lfs_tag_t tag;
const void *buffer;
const struct lfs_mattr *next;
};
#define LFS_MKATTR(type, id, buffer, size, next) \
&(const struct lfs_mattr){LFS_MKTAG(type, id, size), (buffer), (next)}
struct lfs_diskoff {
lfs_block_t block;
lfs_off_t off;
};
// operations on set of globals
static inline void lfs_global_xor(lfs_global_t *a, const lfs_global_t *b) {
for (int i = 0; i < sizeof(lfs_global_t)/4; i++) {
a->u32[i] ^= b->u32[i];
}
}
static inline bool lfs_global_iszero(const lfs_global_t *a) {
for (int i = 0; i < sizeof(lfs_global_t)/4; i++) {
if (a->u32[i] != 0) {
return false;
}
}
return true;
}
static inline void lfs_global_zero(lfs_global_t *a) {
memset(a, 0, sizeof(lfs_global_t));
}
static inline void lfs_global_fromle32(lfs_global_t *a) {
lfs_pair_fromle32(a->l.movepair);
a->l.moveid = lfs_fromle16(a->l.moveid);
}
static inline void lfs_global_tole32(lfs_global_t *a) {
lfs_pair_tole32(a->l.movepair);
a->l.moveid = lfs_tole16(a->l.moveid);
}
static inline void lfs_global_move(lfs_t *lfs,
const lfs_block_t pair[2], uint16_t id) {
lfs_global_t diff;
lfs_global_zero(&diff);
diff.l.movepair[0] ^= lfs->globals.g.movepair[0] ^ pair[0];
diff.l.movepair[1] ^= lfs->globals.g.movepair[1] ^ pair[1];
diff.l.moveid ^= lfs->globals.g.moveid ^ id;
lfs_global_fromle32(&lfs->locals);
lfs_global_xor(&lfs->locals, &diff);
lfs_global_tole32(&lfs->locals);
lfs_global_xor(&lfs->globals, &diff);
}
static inline void lfs_global_orphans(lfs_t *lfs, int8_t orphans) {
lfs->locals.l.deorphaned ^= (lfs->globals.g.orphans == 0);
lfs->locals.l.deorphaned ^= (lfs->globals.g.orphans + orphans == 0);
lfs->globals.g.orphans += orphans;
}
// other endianness operations
static void lfs_ctz_fromle32(struct lfs_ctz *ctz) {
ctz->head = lfs_fromle32(ctz->head);
ctz->size = lfs_fromle32(ctz->size);
}
static void lfs_ctz_tole32(struct lfs_ctz *ctz) {
ctz->head = lfs_tole32(ctz->head);
ctz->size = lfs_tole32(ctz->size);
}
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->inline_max = lfs_fromle32(superblock->inline_max);
superblock->attr_max = lfs_fromle32(superblock->attr_max);
superblock->name_max = lfs_fromle32(superblock->name_max);
}
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->inline_max = lfs_tole32(superblock->inline_max);
superblock->attr_max = lfs_tole32(superblock->attr_max);
superblock->name_max = lfs_tole32(superblock->name_max);
}
/// Internal operations predeclared here ///
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_relocate(lfs_t *lfs,
const lfs_block_t oldpair[2], lfs_block_t newpair[2]);
static int lfs_fs_forceconsistency(lfs_t *lfs);
static int lfs_deinit(lfs_t *lfs);
/// Block allocator ///
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;
}
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;
}
return 0;
}
}
// check if we have looked at all blocks since last ack
if (lfs->free.ack == 0) {
LFS_WARN("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(lfs->cfg->lookahead, lfs->free.ack);
lfs->free.i = 0;
// find mask of free blocks from tree
memset(lfs->free.buffer, 0, lfs->cfg->lookahead/8);
int err = lfs_fs_traverse(lfs, lfs_alloc_lookahead, lfs);
if (err) {
return err;
}
}
}
static void lfs_alloc_ack(lfs_t *lfs) {
lfs->free.ack = lfs->cfg->block_count;
}
/// Metadata pair and directory operations ///
static int lfs_dir_traverse(lfs_t *lfs,
const lfs_mdir_t *dir, const struct lfs_mattr *attrs,
lfs_tag_t matchmask, lfs_tag_t matchtag, lfs_stag_t matchdiff,
int (*cb)(void *data, lfs_tag_t tag, const void *buffer), void *data) {
lfs_block_t block = dir->pair[0];
lfs_off_t off = dir->off;
lfs_tag_t ntag = dir->etag;
bool lastcommit = false;
matchtag += matchdiff;
// iterate over dir block backwards (for faster lookups)
while (attrs || off >= sizeof(lfs_tag_t) + lfs_tag_dsize(ntag)) {
lfs_tag_t tag;
const void *buffer;
struct lfs_diskoff disk;
if (attrs) {
tag = attrs->tag;
buffer = attrs->buffer;
attrs = attrs->next;
} else {
off -= lfs_tag_dsize(ntag);
tag = ntag;
buffer = &disk;
disk.block = block;
disk.off = off + sizeof(tag);
int err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, sizeof(ntag),
block, off, &ntag, sizeof(ntag));
if (err) {
return err;
}
ntag = lfs_fromle32(ntag) ^ tag;
tag |= 0x80000000;
}
if (lfs_tag_subtype(tag) == LFS_TYPE_CRC) {
lastcommit = 2 & lfs_tag_type(tag);
} else if (lfs_tag_subtype(tag) == LFS_TYPE_DELETE) {
// something was deleted, need to move around it
if (lfs_tag_id(tag) <= lfs_tag_id(matchtag - matchdiff)) {
matchdiff -= LFS_MKTAG(0, 1, 0);
}
}
if ((tag & matchmask) == ((matchtag - matchdiff) & matchmask) &&
!(lfs_tag_isdelete(tag) && lastcommit)) {
int res = cb(data, tag + matchdiff, buffer);
if (res) {
return res;
}
}
if (lfs_tag_subtype(tag) == LFS_TYPE_NAME) {
// found where something was created
if (lfs_tag_id(tag) == lfs_tag_id(matchtag - matchdiff)) {
break;
} else if (lfs_tag_id(tag) < lfs_tag_id(matchtag - matchdiff)) {
matchdiff += LFS_MKTAG(0, 1, 0);
}
}
}
return 0;
}
static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
lfs_mdir_t *dir, const lfs_block_t pair[2],
lfs_tag_t matchmask, lfs_tag_t matchtag,
int (*cb)(void *data, lfs_tag_t tag, const void *buffer), void *data) {
// find the block with the most recent revision
uint32_t revs[2];
int r = 0;
for (int i = 0; i < 2; i++) {
int err = lfs_bd_read(lfs,
&lfs->pcache, &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 (lfs_scmp(revs[i], revs[(i+1)%2]) > 0 || err == LFS_ERR_CORRUPT) {
r = i;
}
}
// now fetch the actual dir (and find match)
lfs_stag_t foundtag = LFS_ERR_NOENT;
dir->pair[0] = pair[0];
dir->pair[1] = pair[1];
dir->off = 0;
if (r != 0) {
lfs_pair_swap(dir->pair);
lfs_pair_swap(revs);
}
// scan tags and check crcs
for (int i = 0; i < 2; i++) {
lfs_block_t block = dir->pair[0];
lfs_off_t off = sizeof(uint32_t);
lfs_tag_t ptag = 0xffffffff;
lfs_tag_t tempfoundtag = foundtag;
lfs_mdir_t temp = {
.pair = {dir->pair[0], dir->pair[1]},
.rev = revs[0],
.tail = {0xffffffff, 0xffffffff},
.split = false,
.count = 0,
};
lfs_global_zero(&temp.locals);
temp.rev = lfs_tole32(temp.rev);
uint32_t crc = lfs_crc(0xffffffff, &temp.rev, sizeof(temp.rev));
temp.rev = lfs_fromle32(temp.rev);
while (true) {
// extract next tag
lfs_tag_t tag;
int err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, lfs->cfg->block_size,
block, off, &tag, sizeof(tag));
if (err) {
if (err == LFS_ERR_CORRUPT) {
// can't continue?
dir->erased = false;
break;
}
return err;
}
crc = lfs_crc(crc, &tag, sizeof(tag));
tag = lfs_fromle32(tag) ^ ptag;
// next commit not yet programmed
if (!lfs_tag_isvalid(tag)) {
dir->erased = (lfs_tag_subtype(ptag) == LFS_TYPE_CRC);
break;
}
// check we're in valid range
if (off + lfs_tag_dsize(tag) > lfs->cfg->block_size) {
dir->erased = false;
break;
}
if (lfs_tag_subtype(tag) == LFS_TYPE_CRC) {
// check the crc attr
uint32_t dcrc;
err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, lfs->cfg->block_size,
block, off+sizeof(tag), &dcrc, sizeof(dcrc));
if (err) {
if (err == LFS_ERR_CORRUPT) {
dir->erased = false;
break;
}
return err;
}
dcrc = lfs_fromle32(dcrc);
if (crc != dcrc) {
dir->erased = false;
break;
}
// reset the next bit if we need to
tag ^= (lfs_tag_type(tag) & 1) << 31;
lfs->seed ^= crc;
crc = 0xffffffff;
// update with what's found so far
foundtag = tempfoundtag;
*dir = temp;
dir->off = off + lfs_tag_dsize(tag);
dir->etag = tag;
} else {
// crc the entry first, leaving it in the cache
for (lfs_off_t j = sizeof(tag); j < lfs_tag_dsize(tag); j++) {
uint8_t dat;
err = lfs_bd_read(lfs,
NULL, &lfs->rcache, lfs->cfg->block_size,
block, off+j, &dat, 1);
if (err) {
if (err == LFS_ERR_CORRUPT) {
dir->erased = false;
break;
}
return err;
}
crc = lfs_crc(crc, &dat, 1);
}
// check for special tags
if (lfs_tag_subtype(tag) == LFS_TYPE_NAME) {
temp.count += 1;
if (lfs_tag_isvalid(tempfoundtag) &&
lfs_tag_id(tag) <= lfs_tag_id(tempfoundtag)) {
tempfoundtag += LFS_MKTAG(0, 1, 0);
}
} else if (lfs_tag_subtype(tag) == LFS_TYPE_DELETE) {
LFS_ASSERT(temp.count > 0);
temp.count -= 1;
if (lfs_tag_id(tag) == lfs_tag_id(tempfoundtag)) {
tempfoundtag = LFS_ERR_NOENT;
} else if (lfs_tag_isvalid(tempfoundtag) &&
lfs_tag_id(tag) < lfs_tag_id(tempfoundtag)) {
tempfoundtag -= LFS_MKTAG(0, 1, 0);
}
} else if (lfs_tag_subtype(tag) == LFS_TYPE_TAIL) {
temp.split = (lfs_tag_type(tag) & 1);
err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, lfs->cfg->block_size,
block, off+sizeof(tag),
&temp.tail, sizeof(temp.tail));
if (err) {
if (err == LFS_ERR_CORRUPT) {
dir->erased = false;
break;
}
}
lfs_pair_fromle32(temp.tail);
} else if (lfs_tag_subtype(tag) == LFS_TYPE_GLOBALS) {
temp.locals.l.deorphaned = (lfs_tag_type(tag) & 1);
err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, lfs->cfg->block_size,
block, off+sizeof(tag),
&temp.locals, 10);
if (err) {
if (err == LFS_ERR_CORRUPT) {
dir->erased = false;
break;
}
}
}
if ((tag & matchmask) == (matchtag & matchmask)) {
// found a match?
if (lfs_tag_isdelete(tag)) {
tempfoundtag = LFS_ERR_NOENT;
} else if (cb) {
int res = cb(data, tag, &(struct lfs_diskoff){
block, off+sizeof(tag)});
if (res < 0) {
if (res == LFS_ERR_CORRUPT) {
dir->erased = false;
break;
}
return res;
}
if (res) {
tempfoundtag = tag;
}
}
}
}
ptag = tag;
off += lfs_tag_dsize(tag);
}
// consider what we have good enough
if (dir->off > 0) {
// synthetic move
if (lfs_pair_cmp(dir->pair, lfs->globals.g.movepair) == 0) {
if (lfs->globals.g.moveid == lfs_tag_id(foundtag)) {
foundtag = LFS_ERR_NOENT;
} else if (lfs_tag_isvalid(foundtag) &&
lfs->globals.g.moveid < lfs_tag_id(foundtag)) {
foundtag -= LFS_MKTAG(0, 1, 0);
}
}
return foundtag;
}
// failed, try the other crc?
lfs_pair_swap(dir->pair);
lfs_pair_swap(revs);
}
LFS_ERROR("Corrupted dir pair at %"PRIu32" %"PRIu32,
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]) {
lfs_stag_t res = lfs_dir_fetchmatch(lfs, dir, pair, 0, 0, NULL, NULL);
if (res < 0 && res != LFS_ERR_NOENT) {
return res;
}
return 0;
}
static lfs_stag_t lfs_dir_findmatch(lfs_t *lfs,
lfs_mdir_t *dir, const lfs_block_t pair[2], bool fs,
lfs_tag_t findmask, lfs_tag_t findtag,
int (*cb)(void *data, lfs_tag_t tag, const void *buffer), void *data) {
dir->split = true;
dir->tail[0] = pair[0];
dir->tail[1] = pair[1];
while ((dir->split || fs) && !lfs_pair_isnull(dir->tail)) {
lfs_stag_t tag = lfs_dir_fetchmatch(lfs, dir, dir->tail,
findmask, findtag, cb, data);
if (tag != LFS_ERR_NOENT) {
return tag;
}
}
return LFS_ERR_NOENT;
}
struct lfs_dir_get_match {
lfs_t *lfs;
void *buffer;
lfs_size_t size;
bool compacting;
};
static int lfs_dir_get_match(void *data,
lfs_tag_t tag, const void *buffer) {
struct lfs_dir_get_match *get = data;
lfs_t *lfs = get->lfs;
const struct lfs_diskoff *disk = buffer;
if (lfs_tag_isdelete(tag) && !get->compacting) {
return LFS_ERR_NOENT;
}
if (get->buffer) {
lfs_size_t diff = lfs_min(lfs_tag_size(tag), get->size);
int err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, diff,
disk->block, disk->off, get->buffer, diff);
if (err) {
return err;
}
memset((uint8_t*)get->buffer + diff, 0, get->size - diff);
}
return tag & 0x7fffffff;
}
static lfs_stag_t lfs_dir_get(lfs_t *lfs, lfs_mdir_t *dir,
lfs_tag_t getmask, lfs_tag_t gettag, void *buffer) {
lfs_stag_t getdiff = 0;
if (lfs_pair_cmp(dir->pair, lfs->globals.g.movepair) == 0 &&
lfs_tag_id(gettag) <= lfs->globals.g.moveid) {
// synthetic moves
gettag += LFS_MKTAG(0, 1, 0);
getdiff -= LFS_MKTAG(0, 1, 0);
}
lfs_stag_t res = lfs_dir_traverse(lfs, dir, NULL,
getmask, gettag, getdiff,
lfs_dir_get_match, &(struct lfs_dir_get_match){
lfs, buffer, lfs_tag_size(gettag)});
if (res < 0) {
return res;
}
return res ? res : LFS_ERR_NOENT;
}
// 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;
lfs_off_t ack;
};
static int lfs_commit_prog(lfs_t *lfs, struct lfs_commit *commit,
const void *buffer, lfs_size_t size) {
lfs_off_t skip = lfs_min(lfs_max(commit->ack, commit->off)
- commit->off, size);
int err = lfs_bd_prog(lfs,
&lfs->pcache, &lfs->rcache, false,
commit->block, commit->off + skip,
(const uint8_t*)buffer + skip, size - skip);
if (err) {
return err;
}
commit->crc = lfs_crc(commit->crc, buffer, size);
commit->off += size;
commit->ack = lfs_max(commit->off, commit->ack);
return 0;
}
static int lfs_commit_attr(lfs_t *lfs, struct lfs_commit *commit,
lfs_tag_t tag, const void *buffer);
struct lfs_commit_move_match {
lfs_t *lfs;
struct lfs_commit *commit;
int pass;
};
static int lfs_commit_move_match(void *data,
lfs_tag_t tag, const void *buffer) {
struct lfs_commit_move_match *move = data;
lfs_t *lfs = move->lfs;
struct lfs_commit *commit = move->commit;
if (move->pass == 0) {
if (lfs_tag_subtype(tag) != LFS_TYPE_NAME) {
return 0;
}
} else {
// check if type has already been committed
lfs_stag_t res = lfs_dir_traverse(lfs, &(const lfs_mdir_t){
.pair[0] = commit->block,
.off = commit->off,
.etag = commit->ptag}, NULL,
lfs_tag_isuser(tag) ? 0x7ffff000 : 0x7c3ff000, tag, 0,
lfs_dir_get_match, &(struct lfs_dir_get_match){
lfs, NULL, 0, true});
if (res < 0 && res != LFS_ERR_NOENT) {
return res;
}
if (res > 0) {
return 0;
}
}
// update id and commit, as we are currently unique
return lfs_commit_attr(lfs, commit, tag, buffer);
}
static int lfs_commit_move(lfs_t *lfs, struct lfs_commit *commit, int pass,
lfs_tag_t frommask, lfs_tag_t fromtag, lfs_stag_t fromdiff,
const lfs_mdir_t *dir, const struct lfs_mattr *attrs) {
return lfs_dir_traverse(lfs, dir, attrs,
frommask, fromtag, fromdiff,
lfs_commit_move_match, &(struct lfs_commit_move_match){
lfs, commit, pass});
}
static int lfs_commit_userattrs(lfs_t *lfs, struct lfs_commit *commit,
uint16_t id, const struct lfs_attr *attrs) {
for (const struct lfs_attr *a = attrs; a; a = a->next) {
int err = lfs_commit_attr(lfs, commit,
LFS_MKTAG(0x100 | a->type, id, a->size), a->buffer);
if (err) {
return err;
}
}
return 0;
}
static int lfs_commit_attr(lfs_t *lfs, struct lfs_commit *commit,
lfs_tag_t tag, const void *buffer) {
if (lfs_tag_type(tag) == LFS_FROM_MOVE) {
// special case for moves
return lfs_commit_move(lfs, commit, 1,
0x003ff000, LFS_MKTAG(0, lfs_tag_size(tag), 0),
LFS_MKTAG(0, lfs_tag_id(tag), 0) -
LFS_MKTAG(0, lfs_tag_size(tag), 0),
buffer, NULL);
} else if (lfs_tag_type(tag) == LFS_FROM_USERATTRS) {
// special case for custom attributes
return lfs_commit_userattrs(lfs, commit,
lfs_tag_id(tag), 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_tole32((tag & 0x7fffffff) ^ commit->ptag);
int err = lfs_commit_prog(lfs, commit, &ntag, sizeof(ntag));
if (err) {
return err;
}
if (!(tag & 0x80000000)) {
// from memory
err = lfs_commit_prog(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,
&lfs->pcache, &lfs->rcache, dsize-sizeof(tag)-i,
disk->block, disk->off+i, &dat, 1);
if (err) {
return err;
}
err = lfs_commit_prog(lfs, commit, &dat, 1);
if (err) {
return err;
}
}
}
commit->ptag = tag & 0x7fffffff;
return 0;
}
static int lfs_commit_globals(lfs_t *lfs, struct lfs_commit *commit,
lfs_global_t *locals) {
if (lfs_global_iszero(&lfs->locals)) {
return 0;
}
lfs_global_xor(locals, &lfs->locals);
int err = lfs_commit_attr(lfs, commit,
LFS_MKTAG(LFS_TYPE_GLOBALS + locals->l.deorphaned, 0x3ff, 10),
locals);
lfs_global_xor(locals, &lfs->locals);
return err;
}
static int lfs_commit_crc(lfs_t *lfs, struct lfs_commit *commit,
bool compacting) {
// align to program units
lfs_off_t off = lfs_alignup(commit->off + 2*sizeof(uint32_t),
lfs->cfg->prog_size);
// read erased state from next program unit
lfs_tag_t tag;
int err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, sizeof(tag),
commit->block, off, &tag, sizeof(tag));
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// build crc tag
bool reset = ~lfs_fromle32(tag) >> 31;
tag = LFS_MKTAG(LFS_TYPE_CRC + (compacting << 1) + reset,
0x3ff, off - (commit->off+sizeof(lfs_tag_t)));
// write out crc
uint32_t footer[2];
footer[0] = lfs_tole32(tag ^ commit->ptag);
commit->crc = lfs_crc(commit->crc, &footer[0], sizeof(footer[0]));
footer[1] = lfs_tole32(commit->crc);
err = lfs_bd_prog(lfs,
&lfs->pcache, &lfs->rcache, false,
commit->block, commit->off, &footer, sizeof(footer));
if (err) {
return err;
}
commit->off += sizeof(tag)+lfs_tag_size(tag);
commit->ptag = tag ^ (reset << 31);
// flush buffers
err = lfs_bd_sync(lfs, &lfs->pcache, &lfs->rcache, false);
if (err) {
return err;
}
// successful commit, check checksum to make sure
uint32_t crc = 0xffffffff;
lfs_size_t size = commit->off - lfs_tag_size(tag) - commit->begin;
for (lfs_off_t i = 0; i < size; i++) {
// leave it up to caching to make this efficient
uint8_t dat;
err = lfs_bd_read(lfs,
NULL, &lfs->rcache, size-i,
commit->block, commit->begin+i, &dat, 1);
if (err) {
return err;
}
crc = lfs_crc(crc, &dat, 1);
}
if (err) {
return err;
}
if (crc != commit->crc) {
return LFS_ERR_CORRUPT;
}
return 0;
}
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;
}
}
// rather than clobbering one of the blocks we just pretend
// the revision may be valid
int err = lfs_bd_read(lfs,
&lfs->pcache, &lfs->rcache, sizeof(dir->rev),
dir->pair[0], 0, &dir->rev, sizeof(dir->rev));
if (err) {
return err;
}
dir->rev = lfs_fromle32(dir->rev);
if (err && err != LFS_ERR_CORRUPT) {
return err;
}
// set defaults
dir->off = sizeof(dir->rev);
dir->etag = 0xffffffff;
dir->count = 0;
dir->tail[0] = 0xffffffff;
dir->tail[1] = 0xffffffff;
dir->erased = false;
dir->split = false;
lfs_global_zero(&dir->locals);
// don't write out yet, let caller take care of that
return 0;
}
static int lfs_dir_compact(lfs_t *lfs,
lfs_mdir_t *dir, const struct lfs_mattr *attrs,
lfs_mdir_t *source, uint16_t begin, uint16_t end) {
// save some state in case block is bad
const lfs_block_t oldpair[2] = {dir->pair[1], dir->pair[0]};
bool relocated = false;
// There's nothing special about our global delta, so feed it back
// into the global global delta
lfs_global_xor(&lfs->locals, &dir->locals);
lfs_global_zero(&dir->locals);
while (true) {
// setup compaction
bool splitted = false;
bool exhausted = false;
struct lfs_commit commit;
commit.block = dir->pair[1];
commit.ack = 0;
commit:
// setup erase state
exhausted = false;
dir->count = end - begin;
int16_t ackid = -1;
// setup commit state
commit.off = 0;
commit.crc = 0xffffffff;
commit.ptag = 0xffffffff;
// space is complicated, we need room for tail, crc, globals,
// cleanup delete, and we cap at half a block to give room
// for metadata updates
commit.begin = 0;
commit.end = lfs_min(
lfs_alignup(lfs->cfg->block_size/2, lfs->cfg->prog_size),
lfs->cfg->block_size - 38);
if (!splitted) {
// increment revision count
dir->rev += 1;
if (lfs->cfg->block_cycles &&
dir->rev % lfs->cfg->block_cycles == 0) {
if (lfs_pair_cmp(dir->pair,
(const lfs_block_t[2]){0, 1}) == 0) {
// we're writing too much to the superblock,
// should we expand?
lfs_ssize_t res = lfs_fs_size(lfs);
if (res < 0) {
return res;
}
// do we have enough space to expand?
if (res < lfs->cfg->block_count/2) {
LFS_DEBUG("Expanding superblock at rev %"PRIu32,
dir->rev);
exhausted = true;
goto split;
}
} else {
// we're writing too much, time to relocate
exhausted = true;
goto relocate;
}
}
// 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
uint32_t rev = lfs_tole32(dir->rev);
int err = lfs_commit_prog(lfs, &commit, &rev, sizeof(rev));
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
// commit with a move
for (uint16_t id = begin; id < end || commit.off < commit.ack; id++) {
for (int pass = 0; pass < 2; pass++) {
err = lfs_commit_move(lfs, &commit, pass,
0x003ff000, LFS_MKTAG(0, id, 0),
-LFS_MKTAG(0, begin, 0),
source, attrs);
if (err && !(splitted && err == LFS_ERR_NOSPC)) {
if (err == LFS_ERR_NOSPC) {
goto split;
} else if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
}
ackid = id;
}
// reopen reserved space at the end
commit.end = lfs->cfg->block_size - 8;
if (ackid >= end) {
// extra garbage attributes were written out during split,
// need to clean up
err = lfs_commit_attr(lfs, &commit,
LFS_MKTAG(LFS_TYPE_DELETE, ackid, 0), NULL);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
}
if (!relocated) {
// commit any globals, unless we're relocating,
// in which case our parent will steal our globals
err = lfs_commit_globals(lfs, &commit, &dir->locals);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
}
if (!lfs_pair_isnull(dir->tail)) {
// commit tail, which may be new after last size check
lfs_pair_tole32(dir->tail);
err = lfs_commit_attr(lfs, &commit,
LFS_MKTAG(LFS_TYPE_TAIL + dir->split,
0x3ff, sizeof(dir->tail)), dir->tail);
lfs_pair_fromle32(dir->tail);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
}
err = lfs_commit_crc(lfs, &commit, true);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
// successful compaction, swap dir pair to indicate most recent
lfs_pair_swap(dir->pair);
dir->off = commit.off;
dir->etag = commit.ptag;
dir->erased = true;
break;
split:
// commit no longer fits, need to split dir,
// drop caches and create tail
splitted = !exhausted;
if (lfs->pcache.block != 0xffffffff) {
commit.ack -= lfs->pcache.size;
lfs_cache_drop(lfs, &lfs->pcache);
}
if (!exhausted && ackid < 0) {
// If we can't fit in this block, we won't fit in next block
return LFS_ERR_NOSPC;
}
lfs_mdir_t tail;
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];
err = lfs_dir_compact(lfs, &tail, attrs, source, ackid+1, end);
if (err) {
return err;
}
end = ackid+1;
dir->tail[0] = tail.pair[0];
dir->tail[1] = tail.pair[1];
dir->split = true;
if (exhausted) {
lfs->root[0] = tail.pair[0];
lfs->root[1] = tail.pair[1];
}
goto commit;
relocate:
// commit was corrupted, drop caches and prepare to relocate block
relocated = true;
lfs_cache_drop(lfs, &lfs->pcache);
if (!exhausted) {
LFS_DEBUG("Bad block at %"PRIu32, dir->pair[1]);
}
// can't relocate superblock, filesystem is now frozen
if (lfs_pair_cmp(oldpair, (const lfs_block_t[2]){0, 1}) == 0) {
LFS_WARN("Superblock %"PRIu32" has become unwritable", oldpair[1]);
return LFS_ERR_NOSPC;
}
// relocate half of pair
err = lfs_alloc(lfs, &dir->pair[1]);
if (err && (err != LFS_ERR_NOSPC && !exhausted)) {
return err;
}
continue;
}
if (!relocated) {
// successful commit, update globals
lfs_global_xor(&dir->locals, &lfs->locals);
lfs_global_zero(&lfs->locals);
} else {
// update references if we relocated
LFS_DEBUG("Relocating %"PRIu32" %"PRIu32" to %"PRIu32" %"PRIu32,
oldpair[0], oldpair[1], dir->pair[0], dir->pair[1]);
int err = lfs_fs_relocate(lfs, oldpair, dir->pair);
if (err) {
return err;
}
}
return 0;
}
static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
const struct lfs_mattr *attrs) {
struct lfs_mattr cancelattr;
lfs_global_t canceldiff;
lfs_global_zero(&canceldiff);
if (lfs_pair_cmp(dir->pair, lfs->globals.g.movepair) == 0) {
// Wait, we have the move? Just cancel this out here
// We need to, or else the move can become outdated
canceldiff.l.movepair[0] ^= lfs->globals.g.movepair[0] ^ 0xffffffff;
canceldiff.l.movepair[1] ^= lfs->globals.g.movepair[1] ^ 0xffffffff;
canceldiff.l.moveid ^= lfs->globals.g.moveid ^ 0x3ff;
lfs_global_fromle32(&lfs->locals);
lfs_global_xor(&lfs->locals, &canceldiff);
lfs_global_tole32(&lfs->locals);
cancelattr.tag = LFS_MKTAG(LFS_TYPE_DELETE, lfs->globals.l.moveid, 0);
cancelattr.next = attrs;
attrs = &cancelattr;
}
// calculate new directory size
lfs_tag_t deletetag = 0xffffffff;
int attrcount = 0;
for (const struct lfs_mattr *a = attrs; a; a = a->next) {
if (lfs_tag_subtype(a->tag) == LFS_TYPE_NAME) {
dir->count += 1;
} else if (lfs_tag_subtype(a->tag) == LFS_TYPE_DELETE) {
LFS_ASSERT(dir->count > 0);
dir->count -= 1;
deletetag = a->tag;
if (dir->count == 0) {
// should we actually drop the directory block?
lfs_mdir_t 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) {
// steal tail and global state
pdir.split = dir->split;
pdir.tail[0] = dir->tail[0];
pdir.tail[1] = dir->tail[1];
lfs_global_xor(&lfs->locals, &dir->locals);
return lfs_dir_commit(lfs, &pdir,
LFS_MKATTR(LFS_TYPE_TAIL + pdir.split, 0x3ff,
pdir.tail, sizeof(pdir.tail),
NULL));
}
}
}
attrcount += 1;
}
while (true) {
if (!dir->erased) {
goto compact;
}
// try to commit
struct lfs_commit commit = {
.block = dir->pair[0],
.off = dir->off,
.crc = 0xffffffff,
.ptag = dir->etag,
.begin = dir->off,
.end = lfs->cfg->block_size - 8,
.ack = 0,
};
// iterate over commits backwards, this lets us "append" commits
for (int i = 0; i < attrcount; i++) {
const struct lfs_mattr *a = attrs;
for (int j = 0; j < attrcount-i-1; j++) {
a = a->next;
}
lfs_pair_tole32(dir->tail);
int err = lfs_commit_attr(lfs, &commit, a->tag, a->buffer);
lfs_pair_fromle32(dir->tail);
if (err) {
if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
goto compact;
}
return err;
}
}
int err = lfs_commit_globals(lfs, &commit, &dir->locals);
if (err) {
if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
goto compact;
}
return err;
}
err = lfs_commit_crc(lfs, &commit, false);
if (err) {
if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
goto compact;
}
return err;
}
// successful commit, update dir
dir->off = commit.off;
dir->etag = commit.ptag;
// successful commit, update globals
lfs_global_xor(&dir->locals, &lfs->locals);
lfs_global_zero(&lfs->locals);
break;
compact:
// fall back to compaction
lfs_cache_drop(lfs, &lfs->pcache);
err = lfs_dir_compact(lfs, dir, attrs, dir, 0, dir->count);
if (err) {
return err;
}
break;
}
// update globals that are affected
lfs_global_xor(&lfs->globals, &canceldiff);
// update any directories that are affected
lfs_mdir_t copy = *dir;
// two passes, once for things that aren't us, and one
// for things that are
for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
if (lfs_pair_cmp(d->m.pair, copy.pair) == 0) {
d->m = *dir;
if (d->id == lfs_tag_id(deletetag)) {
d->m.pair[0] = 0xffffffff;
d->m.pair[1] = 0xffffffff;
} else if (d->id > lfs_tag_id(deletetag)) {
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 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;
(void)tag;
return lfs_bd_cmp(lfs,
NULL, &lfs->rcache, name->size,
disk->block, disk->off, name->name, name->size);
}
static lfs_stag_t lfs_dir_find(lfs_t *lfs,
lfs_mdir_t *dir, const char **path) {
// we reduce path to a single name if we can find it
const char *name = *path;
*path = NULL;
// default to root dir
lfs_stag_t tag = LFS_MKTAG(LFS_TYPE_DIR, 0x3ff, 0);
lfs_block_t pair[2] = {lfs->root[0], 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 if path is only a name
if (strchr(name, '/') == NULL) {
*path = name;
}
// only continue if we hit a directory
if (lfs_tag_type(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, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tag_id(tag), 8), pair);
if (res < 0) {
return res;
}
lfs_pair_fromle32(pair);
}
// find entry matching name
tag = lfs_dir_findmatch(lfs, dir, pair, false, 0x7c000fff,
LFS_MKTAG(LFS_TYPE_NAME, 0, namelen),
lfs_dir_find_match, &(struct lfs_dir_find_match){
lfs, name, namelen});
if (tag < 0) {
return tag;
}
// to next name
name += namelen;
}
}
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, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_NAME, id, lfs->name_max+1), info->name);
if (tag < 0) {
return tag;
}
info->type = lfs_tag_type(tag);
struct lfs_ctz ctz;
tag = lfs_dir_get(lfs, dir, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, id, sizeof(ctz)), &ctz);
if (tag < 0) {
return tag;
}
lfs_ctz_fromle32(&ctz);
if (lfs_tag_type(tag) == LFS_TYPE_CTZSTRUCT) {
info->size = ctz.size;
} else if (lfs_tag_type(tag) == LFS_TYPE_INLINESTRUCT) {
info->size = lfs_tag_size(tag);
}
return 0;
}
/// Top level directory operations ///
int lfs_mkdir(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 res = lfs_dir_find(lfs, &cwd, &path);
if (!(res == LFS_ERR_NOENT && path)) {
return (res < 0) ? res : 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;
}
dir.tail[0] = cwd.tail[0];
dir.tail[1] = cwd.tail[1];
err = lfs_dir_commit(lfs, &dir, NULL);
if (err) {
return err;
}
// get next slot and commit
uint16_t id = cwd.count;
cwd.tail[0] = dir.pair[0];
cwd.tail[1] = dir.pair[1];
lfs_pair_tole32(dir.pair);
err = lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(LFS_TYPE_SOFTTAIL, 0x3ff, cwd.tail, sizeof(cwd.tail),
LFS_MKATTR(LFS_TYPE_DIRSTRUCT, id, dir.pair, sizeof(dir.pair),
LFS_MKATTR(LFS_TYPE_DIR, id, path, nlen,
NULL))));
lfs_pair_fromle32(dir.pair);
if (err) {
return err;
}
return 0;
}
int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
lfs_stag_t tag = lfs_dir_find(lfs, &dir->m, &path);
if (tag < 0) {
return tag;
}
if (lfs_tag_type(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, 0x7c3ff000,
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;
dir->next = (lfs_dir_t*)lfs->mlist;
lfs->mlist = (struct lfs_mlist*)dir;
return 0;
}
int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir) {
// remove from list of mdirs
for (struct lfs_mlist **p = &lfs->mlist; *p; p = &(*p)->next) {
if (*p == (struct lfs_mlist*)dir) {
*p = (*p)->next;
break;
}
}
return 0;
}
int lfs_dir_read(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 1;
} else if (dir->pos == 1) {
info->type = LFS_TYPE_DIR;
strcpy(info->name, "..");
dir->pos += 1;
return 1;
}
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;
}
int lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off) {
// simply walk from head dir
int err = lfs_dir_rewind(lfs, dir);
if (err) {
return err;
}
// first two for ./..
dir->pos = lfs_min(2, off);
off -= dir->pos;
while (off != 0) {
dir->id = lfs_min(dir->m.count, off);
dir->pos += dir->id;
off -= dir->id;
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;
}
}
}
return 0;
}
lfs_soff_t lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir) {
(void)lfs;
return dir->pos;
}
int lfs_dir_rewind(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->m.pair[0] = dir->head[0];
dir->m.pair[1] = dir->head[1];
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 = 0xffffffff;
*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;
}
LFS_ASSERT(head >= 2 && head <= lfs->cfg->block_count);
current -= 1 << skip;
}
*block = head;
*off = pos;
return 0;
}
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;
}
LFS_ASSERT(nblock >= 2 && nblock <= lfs->cfg->block_count);
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;
}
size -= 1;
lfs_off_t index = lfs_ctz_index(lfs, &size);
size += 1;
// just copy out the last block if it is incomplete
if (size != lfs->cfg->block_size) {
for (lfs_off_t i = 0; i < size; i++) {
uint8_t data;
err = lfs_bd_read(lfs,
NULL, rcache, size-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 = size;
return 0;
}
// append block
index += 1;
lfs_size_t skips = lfs_ctz(index) + 1;
for (lfs_off_t i = 0; i < skips; i++) {
head = lfs_tole32(head);
err = lfs_bd_prog(lfs, pcache, rcache, true,
nblock, 4*i, &head, 4);
head = lfs_fromle32(head);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
if (i != skips-1) {
err = lfs_bd_read(lfs,
NULL, rcache, sizeof(head),
head, 4*i, &head, sizeof(head));
head = lfs_fromle32(head);
if (err) {
return err;
}
}
LFS_ASSERT(head >= 2 && head <= lfs->cfg->block_count);
}
*block = nblock;
*off = 4*skips;
return 0;
relocate:
LFS_DEBUG("Bad block at %"PRIu32, nblock);
// just clear cache and try a new block
lfs_cache_drop(lfs, pcache);
}
}
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 ///
int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags,
const struct lfs_file_config *cfg) {
// deorphan if we haven't yet, needed at most once after poweron
if ((flags & 3) != LFS_O_RDONLY) {
int err = lfs_fs_forceconsistency(lfs);
if (err) {
return err;
}
}
// setup simple file details
int err = 0;
file->cfg = cfg;
file->flags = flags;
file->pos = 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);
if (tag < 0 && !(tag == LFS_ERR_NOENT && path)) {
err = tag;
goto cleanup;
}
// get id, add to list of mdirs to catch update changes
file->id = lfs_tag_id(tag);
file->type = LFS_TYPE_REG;
file->next = (lfs_file_t*)lfs->mlist;
lfs->mlist = (struct lfs_mlist*)file;
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
file->id = file->m.count;
err = lfs_dir_commit(lfs, &file->m,
LFS_MKATTR(LFS_TYPE_INLINESTRUCT, file->id, NULL, 0,
LFS_MKATTR(LFS_TYPE_REG, file->id, path, nlen,
NULL)));
if (err) {
err = LFS_ERR_NAMETOOLONG;
goto cleanup;
}
tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, 0);
} else if (flags & LFS_O_EXCL) {
err = LFS_ERR_EXIST;
goto cleanup;
} else if (lfs_tag_type(tag) != LFS_TYPE_REG) {
err = LFS_ERR_ISDIR;
goto cleanup;
} else if (flags & LFS_O_TRUNC) {
// truncate if requested
tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0);
file->flags |= LFS_F_DIRTY;
} else {
// try to load what's on disk, if it's inlined we'll fix it later
tag = lfs_dir_get(lfs, &file->m, 0x7c3ff000,
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 (const struct lfs_attr *a = file->cfg->attrs; a; a = a->next) {
if ((file->flags & 3) != LFS_O_WRONLY) {
lfs_stag_t res = lfs_dir_get(lfs, &file->m, 0x7ffff000,
LFS_MKTAG(0x100 | a->type, file->id, a->size), a->buffer);
if (res < 0 && res != LFS_ERR_NOENT) {
err = res;
goto cleanup;
}
}
if ((file->flags & 3) != LFS_O_RDONLY) {
if (a->size > lfs->attr_max) {
err = LFS_ERR_NOSPC;
goto cleanup;
}
file->flags |= LFS_F_DIRTY;
}
}
// 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_type(tag) == LFS_TYPE_INLINESTRUCT) {
// load inline files
file->ctz.head = 0xfffffffe;
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, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, file->id, file->ctz.size),
file->cache.buffer);
if (res < 0) {
err = res;
goto cleanup;
}
}
}
return 0;
cleanup:
// clean up lingering resources
file->flags |= LFS_F_ERRED;
lfs_file_close(lfs, file);
return err;
}
int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags) {
static const struct lfs_file_config defaults = {0};
return lfs_file_opencfg(lfs, file, path, flags, &defaults);
}
int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
int err = lfs_file_sync(lfs, file);
// remove from list of mdirs
for (struct lfs_mlist **p = &lfs->mlist; *p; p = &(*p)->next) {
if (*p == (struct lfs_mlist*)file) {
*p = (*p)->next;
break;
}
}
// clean up memory
if (!file->cfg->buffer) {
lfs_free(file->cache.buffer);
}
return err;
}
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;
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;
return 0;
relocate:
LFS_DEBUG("Bad block at %"PRIu32, nblock);
// just clear cache and try a new block
lfs_cache_drop(lfs, &lfs->pcache);
}
}
static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
if (file->flags & LFS_F_READING) {
file->flags &= ~LFS_F_READING;
}
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_read(lfs, &orig, &data, 1);
if (res < 0) {
return res;
}
res = lfs_file_write(lfs, file, &data, 1);
if (res < 0) {
return res;
}
// keep our reference to the rcache in sync
if (lfs->rcache.block != 0xffffffff) {
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 %"PRIu32, file->block);
err = lfs_file_relocate(lfs, file);
if (err) {
return err;
}
}
} else {
file->ctz.size = 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;
}
return 0;
}
int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
while (true) {
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
if ((file->flags & LFS_F_DIRTY) &&
!(file->flags & LFS_F_ERRED) &&
!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_MKATTR(LFS_FROM_USERATTRS,
file->id, file->cfg->attrs, 0,
LFS_MKATTR(type, file->id, buffer, size,
NULL)));
if (err) {
if (err == LFS_ERR_NOSPC && (file->flags & LFS_F_INLINE)) {
goto relocate;
}
return err;
}
file->flags &= ~LFS_F_DIRTY;
}
return 0;
relocate:
// inline file doesn't fit anymore
file->block = 0xfffffffe;
file->off = file->pos;
lfs_alloc_ack(lfs);
err = lfs_file_relocate(lfs, file);
if (err) {
return err;
}
file->flags &= ~LFS_F_INLINE;
file->flags |= LFS_F_WRITING;
}
}
lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
void *buffer, lfs_size_t size) {
uint8_t *data = buffer;
lfs_size_t nsize = size;
if ((file->flags & 3) == LFS_O_WRONLY) {
return LFS_ERR_BADF;
}
if (file->flags & LFS_F_WRITING) {
// flush out any writes
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
}
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 = 0xfffffffe;
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);
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;
}
lfs_ssize_t lfs_file_write(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 & 3) == LFS_O_RDONLY) {
return LFS_ERR_BADF;
}
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->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_write(lfs, file, &(uint8_t){0}, 1);
if (res < 0) {
return res;
}
}
}
if ((file->flags & LFS_F_INLINE) &&
file->pos + nsize > lfs->inline_max) {
// inline file doesn't fit anymore
file->block = 0xfffffffe;
file->off = file->pos;
lfs_alloc_ack(lfs);
int err = lfs_file_relocate(lfs, file);
if (err) {
file->flags |= LFS_F_ERRED;
return err;
}
file->flags &= ~LFS_F_INLINE;
file->flags |= LFS_F_WRITING;
}
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 = 0xfffffffe;
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);
}
file->flags &= ~LFS_F_ERRED;
return size;
}
lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
lfs_soff_t off, int whence) {
// write out everything beforehand, may be noop if rdonly
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
// update pos
if (whence == LFS_SEEK_SET) {
file->pos = off;
} else if (whence == LFS_SEEK_CUR) {
if (off < 0 && (lfs_off_t)-off > file->pos) {
return LFS_ERR_INVAL;
}
file->pos = file->pos + off;
} else if (whence == LFS_SEEK_END) {
if (off < 0 && (lfs_off_t)-off > file->ctz.size) {
return LFS_ERR_INVAL;
}
file->pos = file->ctz.size + off;
}
return file->pos;
}
int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
if ((file->flags & 3) == LFS_O_RDONLY) {
return LFS_ERR_BADF;
}
lfs_off_t oldsize = lfs_file_size(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->ctz.head, &(lfs_off_t){0});
if (err) {
return err;
}
file->ctz.size = size;
file->flags |= LFS_F_DIRTY;
} else if (size > oldsize) {
lfs_off_t pos = file->pos;
// flush+seek if not already at end
if (file->pos != oldsize) {
int err = lfs_file_seek(lfs, file, 0, LFS_SEEK_END);
if (err < 0) {
return err;
}
}
// fill with zeros
while (file->pos < size) {
lfs_ssize_t res = lfs_file_write(lfs, file, &(uint8_t){0}, 1);
if (res < 0) {
return res;
}
}
// restore pos
int err = lfs_file_seek(lfs, file, pos, LFS_SEEK_SET);
if (err < 0) {
return err;
}
}
return 0;
}
lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file) {
(void)lfs;
return file->pos;
}
int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file) {
lfs_soff_t res = lfs_file_seek(lfs, file, 0, LFS_SEEK_SET);
if (res < 0) {
return res;
}
return 0;
}
lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file) {
(void)lfs;
if (file->flags & LFS_F_WRITING) {
return lfs_max(file->pos, file->ctz.size);
} else {
return file->ctz.size;
}
}
/// General fs operations ///
int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
lfs_mdir_t cwd;
lfs_stag_t tag = lfs_dir_find(lfs, &cwd, &path);
if (tag < 0) {
return tag;
}
return lfs_dir_getinfo(lfs, &cwd, lfs_tag_id(tag), info);
}
int lfs_remove(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;
err = lfs_dir_fetch(lfs, &cwd, lfs->root);
if (err) {
return err;
}
lfs_stag_t tag = lfs_dir_find(lfs, &cwd, &path);
if (tag < 0) {
return tag;
}
lfs_mdir_t dir;
if (lfs_tag_type(tag) == LFS_TYPE_DIR) {
// must be empty before removal
lfs_block_t pair[2];
lfs_stag_t res = lfs_dir_get(lfs, &cwd, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tag_id(tag), 8), pair);
if (res < 0) {
return res;
}
lfs_pair_fromle32(pair);
err = lfs_dir_fetch(lfs, &dir, pair);
if (err) {
return err;
}
if (dir.count > 0 || dir.split) {
return LFS_ERR_NOTEMPTY;
}
// mark fs as orphaned
lfs_global_orphans(lfs, +1);
}
// delete the entry
err = lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(LFS_TYPE_DELETE, lfs_tag_id(tag), NULL, 0,
NULL));
if (err) {
return err;
}
if (lfs_tag_type(tag) == LFS_TYPE_DIR) {
// fix orphan
lfs_global_orphans(lfs, -1);
err = lfs_fs_pred(lfs, dir.pair, &cwd);
if (err) {
return err;
}
// steal state
cwd.tail[0] = dir.tail[0];
cwd.tail[1] = dir.tail[1];
lfs_global_xor(&lfs->locals, &dir.locals);
err = lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(LFS_TYPE_SOFTTAIL, 0x3ff,
cwd.tail, sizeof(cwd.tail),
NULL));
if (err) {
return err;
}
}
return 0;
}
int lfs_rename(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);
if (oldtag < 0) {
return oldtag;
}
// find new entry
lfs_mdir_t newcwd;
lfs_stag_t prevtag = lfs_dir_find(lfs, &newcwd, &newpath);
if (prevtag < 0 && prevtag != LFS_ERR_NOENT) {
return prevtag;
}
uint16_t newid = lfs_tag_id(prevtag);
lfs_mdir_t prevdir;
if (prevtag == LFS_ERR_NOENT) {
// check that name fits
lfs_size_t nlen = strlen(newpath);
if (nlen > lfs->name_max) {
return LFS_ERR_NAMETOOLONG;
}
// get next id
newid = newcwd.count;
} else if (lfs_tag_type(prevtag) != lfs_tag_type(oldtag)) {
return LFS_ERR_ISDIR;
} else if (lfs_tag_type(prevtag) == LFS_TYPE_DIR) {
// must be empty before removal
lfs_block_t prevpair[2];
lfs_stag_t res = lfs_dir_get(lfs, &newcwd, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, newid, 8), prevpair);
if (res < 0) {
return res;
}
lfs_pair_fromle32(prevpair);
// must be empty before removal
err = lfs_dir_fetch(lfs, &prevdir, prevpair);
if (err) {
return err;
}
if (prevdir.count > 0 || prevdir.split) {
return LFS_ERR_NOTEMPTY;
}
// mark fs as orphaned
lfs_global_orphans(lfs, +1);
}
// create move to fix later
lfs_global_move(lfs, oldcwd.pair, lfs_tag_id(oldtag));
// move over all attributes
err = lfs_dir_commit(lfs, &newcwd,
LFS_MKATTR(LFS_FROM_MOVE, newid, &oldcwd, lfs_tag_id(oldtag),
LFS_MKATTR(lfs_tag_type(oldtag), newid, newpath, strlen(newpath),
(prevtag != LFS_ERR_NOENT)
? LFS_MKATTR(LFS_TYPE_DELETE, newid, NULL, 0, NULL)
: NULL)));
if (err) {
return err;
}
// let commit clean up after move (if we're different! otherwise move
// logic already fixed it for us)
if (lfs_pair_cmp(oldcwd.pair, newcwd.pair) != 0) {
err = lfs_dir_commit(lfs, &oldcwd, NULL);
if (err) {
return err;
}
}
if (prevtag != LFS_ERR_NOENT && lfs_tag_type(prevtag) == LFS_TYPE_DIR) {
// fix orphan
lfs_global_orphans(lfs, -1);
err = lfs_fs_pred(lfs, prevdir.pair, &newcwd);
if (err) {
return err;
}
// steal state
newcwd.tail[0] = prevdir.tail[0];
newcwd.tail[1] = prevdir.tail[1];
lfs_global_xor(&lfs->locals, &prevdir.locals);
err = lfs_dir_commit(lfs, &newcwd,
LFS_MKATTR(LFS_TYPE_SOFTTAIL, 0x3ff,
newcwd.tail, sizeof(newcwd.tail),
NULL));
if (err) {
return err;
}
}
return 0;
}
lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
uint8_t type, void *buffer, lfs_size_t size) {
lfs_mdir_t cwd;
lfs_stag_t res = lfs_dir_find(lfs, &cwd, &path);
if (res < 0) {
return res;
}
uint16_t id = lfs_tag_id(res);
if (id == 0x3ff) {
// special case for root
id = 0;
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
if (err) {
return err;
}
}
res = lfs_dir_get(lfs, &cwd, 0x7ffff000,
LFS_MKTAG(0x100 | type, id, lfs_min(size, lfs->attr_max)),
buffer);
if (res < 0) {
if (res == LFS_ERR_NOENT) {
return LFS_ERR_NOATTR;
}
return res;
}
return lfs_tag_size(res);
}
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 res = lfs_dir_find(lfs, &cwd, &path);
if (res < 0) {
return res;
}
uint16_t id = lfs_tag_id(res);
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_MKATTR(0x100 | type, id, buffer, size,
NULL));
}
int lfs_setattr(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);
}
int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type) {
return lfs_commitattr(lfs, path, type, NULL, LFS_ATTR_MAX+1);
}
/// Filesystem operations ///
static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
lfs->cfg = cfg;
int err = 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);
// 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 32-bits
LFS_ASSERT(lfs->cfg->lookahead % 32 == 0);
LFS_ASSERT(lfs->cfg->lookahead > 0);
if (lfs->cfg->lookahead_buffer) {
lfs->free.buffer = lfs->cfg->lookahead_buffer;
} else {
lfs->free.buffer = lfs_malloc(lfs->cfg->lookahead/8);
if (!lfs->free.buffer) {
err = LFS_ERR_NOMEM;
goto cleanup;
}
}
// check that the size limits are sane
LFS_ASSERT(lfs->cfg->inline_max <= LFS_INLINE_MAX);
LFS_ASSERT(lfs->cfg->inline_max <= lfs->cfg->cache_size);
lfs->inline_max = lfs->cfg->inline_max;
if (!lfs->inline_max) {
lfs->inline_max = lfs_min(LFS_INLINE_MAX, lfs->cfg->cache_size);
}
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->name_max <= LFS_NAME_MAX);
lfs->name_max = lfs->cfg->name_max;
if (!lfs->name_max) {
lfs->name_max = LFS_NAME_MAX;
}
// setup default state
lfs->root[0] = 0xffffffff;
lfs->root[1] = 0xffffffff;
lfs->mlist = NULL;
lfs->seed = 0;
lfs->globals.g.movepair[0] = 0xffffffff;
lfs->globals.g.movepair[1] = 0xffffffff;
lfs->globals.g.moveid = 0x3ff;
lfs->globals.g.orphans = 0;
lfs_global_zero(&lfs->locals);
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;
}
int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
int err = lfs_init(lfs, cfg);
if (err) {
return err;
}
// create free lookahead
memset(lfs->free.buffer, 0, lfs->cfg->lookahead/8);
lfs->free.off = 0;
lfs->free.size = lfs_min(lfs->cfg->lookahead, 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 = {
.magic = {"littlefs"},
.version = LFS_DISK_VERSION,
.block_size = lfs->cfg->block_size,
.block_count = lfs->cfg->block_count,
.attr_max = lfs->attr_max,
.name_max = lfs->name_max,
.inline_max = lfs->inline_max,
};
lfs_superblock_tole32(&superblock);
err = lfs_dir_commit(lfs, &root,
LFS_MKATTR(LFS_TYPE_ROOT, 0, &superblock, sizeof(superblock),
NULL));
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;
}
int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
int err = lfs_init(lfs, cfg);
if (err) {
return err;
}
// find root/superblock
lfs_mdir_t root;
lfs_superblock_t superblock;
lfs_stag_t tag = lfs_dir_findmatch(lfs,
&root, (const lfs_block_t[2]){0, 1}, false, 0x7fc00000,
LFS_MKTAG(LFS_TYPE_ROOT, 0, 8),
lfs_dir_find_match, &(struct lfs_dir_find_match){
lfs, "littlefs", 8});
if (tag < 0) {
err = tag;
goto cleanup;
}
lfs_stag_t res = lfs_dir_get(lfs, &root, 0x7f800000,
LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, sizeof(superblock)),
&superblock);
if (res < 0) {
err = res;
goto cleanup;
}
lfs_superblock_fromle32(&superblock);
lfs->root[0] = root.pair[0];
lfs->root[1] = root.pair[1];
// 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 %"PRIu32".%"PRIu32,
major_version, minor_version);
err = LFS_ERR_INVAL;
goto cleanup;
}
// check superblock configuration
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.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.inline_max) {
if (superblock.inline_max > lfs->inline_max) {
LFS_ERROR("Unsupported inline_max (%"PRIu32" > %"PRIu32")",
superblock.inline_max, lfs->inline_max);
err = LFS_ERR_INVAL;
goto cleanup;
}
lfs->inline_max = superblock.inline_max;
}
// scan for any global updates
lfs_mdir_t dir = {.tail = {0, 1}};
while (!lfs_pair_isnull(dir.tail)) {
err = lfs_dir_fetch(lfs, &dir, dir.tail);
if (err) {
err = LFS_ERR_INVAL;
goto cleanup;
}
// xor together indirect deletes
lfs_global_xor(&lfs->locals, &dir.locals);
}
// update littlefs with globals
lfs_global_fromle32(&lfs->locals);
lfs_global_xor(&lfs->globals, &lfs->locals);
lfs_global_zero(&lfs->locals);
if (!lfs_pair_isnull(lfs->globals.g.movepair)) {
LFS_DEBUG("Found move %"PRIu32" %"PRIu32" %"PRIu32,
lfs->globals.g.movepair[0],
lfs->globals.g.movepair[1],
lfs->globals.g.moveid);
}
// setup free lookahead
lfs->free.off = lfs->seed % lfs->cfg->block_size;
lfs->free.size = 0;
lfs->free.i = 0;
lfs_alloc_ack(lfs);
return 0;
cleanup:
lfs_unmount(lfs);
return err;
}
int lfs_unmount(lfs_t *lfs) {
return lfs_deinit(lfs);
}
/// Filesystem filesystem operations ///
int lfs_fs_traverse(lfs_t *lfs,
int (*cb)(void *data, lfs_block_t block), void *data) {
if (lfs_pair_isnull(lfs->root)) {
return 0;
}
// iterate over metadata pairs
lfs_mdir_t dir = {.tail = {0, 1}};
while (!lfs_pair_isnull(dir.tail)) {
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, 0x7c3ff000,
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_type(tag) == LFS_TYPE_CTZSTRUCT) {
err = lfs_ctz_traverse(lfs, NULL, &lfs->rcache,
ctz.head, ctz.size, cb, data);
if (err) {
return err;
}
}
}
}
// 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;
}
}
}
return 0;
}
static int lfs_fs_pred(lfs_t *lfs,
const lfs_block_t pair[2], lfs_mdir_t *pdir) {
if (lfs_pair_isnull(lfs->root)) {
return LFS_ERR_NOENT;
}
// iterate over all directory directory entries
pdir->tail[0] = 0;
pdir->tail[1] = 1;
while (!lfs_pair_isnull(pdir->tail)) {
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;
}
struct lfs_fs_parent_match {
lfs_t *lfs;
const lfs_block_t pair[2];
};
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);
}
static lfs_stag_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t pair[2],
lfs_mdir_t *parent) {
if (lfs_pair_isnull(lfs->root)) {
return LFS_ERR_NOENT;
}
// search for both orderings so we can reuse the find function
for (int i = 0; i < 2; i++) {
struct lfs_fs_parent_match match = {lfs, {pair[0], pair[1]}};
lfs_stag_t tag = lfs_dir_findmatch(lfs, parent,
(const lfs_block_t[2]){0, 1}, true, 0x7fc00fff,
LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 0, 8),
lfs_fs_parent_match, &match);
if (tag != LFS_ERR_NOENT) {
return tag;
}
}
return LFS_ERR_NOENT;
}
static int lfs_fs_relocate(lfs_t *lfs,
const lfs_block_t oldpair[2], lfs_block_t newpair[2]) {
// update internal root
if (lfs_pair_cmp(oldpair, lfs->root) == 0) {
LFS_DEBUG("Relocating root %"PRIu32" %"PRIu32,
newpair[0], newpair[1]);
lfs->root[0] = newpair[0];
lfs->root[1] = newpair[1];
}
// update internally tracked dirs
for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
if (lfs_pair_cmp(oldpair, d->m.pair) == 0) {
d->m.pair[0] = newpair[0];
d->m.pair[1] = newpair[1];
}
}
// find parent
lfs_mdir_t parent;
lfs_stag_t tag = lfs_fs_parent(lfs, oldpair, &parent);
if (tag < 0 && tag != LFS_ERR_NOENT) {
return tag;
}
if (tag != LFS_ERR_NOENT) {
// update disk, this creates a desync
lfs_global_orphans(lfs, +1);
lfs_pair_tole32(newpair);
int err = lfs_dir_commit(lfs, &parent,
&(struct lfs_mattr){.tag=tag, .buffer=newpair});
lfs_pair_fromle32(newpair);
if (err) {
return err;
}
// next step, clean up orphans
lfs_global_orphans(lfs, -1);
}
// find pred
int err = lfs_fs_pred(lfs, oldpair, &parent);
if (err && err != LFS_ERR_NOENT) {
return err;
}
// if we can't find dir, it must be new
if (err != LFS_ERR_NOENT) {
// replace bad pair, either we clean up desync, or no desync occured
parent.tail[0] = newpair[0];
parent.tail[1] = newpair[1];
err = lfs_dir_commit(lfs, &parent,
LFS_MKATTR(LFS_TYPE_TAIL + parent.split, 0x3ff,
parent.tail, sizeof(parent.tail),
NULL));
if (err) {
return err;
}
}
return 0;
}
static int lfs_fs_deorphan(lfs_t *lfs) {
// Fix any orphans
lfs_mdir_t pdir = {.split = true};
lfs_mdir_t dir = {.tail = {0, 1}};
// iterate over all directory directory entries
while (!lfs_pair_isnull(dir.tail)) {
int err = lfs_dir_fetch(lfs, &dir, dir.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 (tag == LFS_ERR_NOENT) {
// we are an orphan
LFS_DEBUG("Fixing orphan %"PRIu32" %"PRIu32,
pdir.tail[0], pdir.tail[1]);
pdir.tail[0] = dir.tail[0];
pdir.tail[1] = dir.tail[1];
err = lfs_dir_commit(lfs, &pdir,
LFS_MKATTR(LFS_TYPE_SOFTTAIL, 0x3ff,
pdir.tail, sizeof(pdir.tail),
NULL));
if (err) {
return err;
}
break;
}
lfs_block_t pair[2];
lfs_stag_t res = lfs_dir_get(lfs, &parent, 0x7ffff000, tag, pair);
if (res < 0) {
return res;
}
lfs_pair_fromle32(pair);
if (!lfs_pair_sync(pair, pdir.tail)) {
// we have desynced
LFS_DEBUG("Fixing half-orphan %"PRIu32" %"PRIu32,
pair[0], pair[1]);
pdir.tail[0] = pair[0];
pdir.tail[1] = pair[1];
err = lfs_dir_commit(lfs, &pdir,
LFS_MKATTR(LFS_TYPE_SOFTTAIL, 0x3ff,
pdir.tail, sizeof(pdir.tail),
NULL));
if (err) {
return err;
}
break;
}
}
memcpy(&pdir, &dir, sizeof(pdir));
}
// mark orphans as fixed
lfs_global_orphans(lfs, -lfs->globals.g.orphans);
return 0;
}
static int lfs_fs_demove(lfs_t *lfs) {
// Fix bad moves
LFS_DEBUG("Fixing move %"PRIu32" %"PRIu32" %"PRIu32,
lfs->globals.g.movepair[0],
lfs->globals.g.movepair[1],
lfs->globals.g.moveid);
// fetch and delete the moved entry
lfs_mdir_t movedir;
int err = lfs_dir_fetch(lfs, &movedir, lfs->globals.g.movepair);
if (err) {
return err;
}
// rely on cancel logic inside commit
err = lfs_dir_commit(lfs, &movedir, NULL);
if (err) {
return err;
}
return 0;
}
static int lfs_fs_forceconsistency(lfs_t *lfs) {
if (lfs->globals.g.orphans) {
int err = lfs_fs_deorphan(lfs);
if (err) {
return err;
}
}
if (lfs->globals.g.moveid != 0x3ff) {
int err = lfs_fs_demove(lfs);
if (err) {
return err;
}
}
return 0;
}
static int lfs_fs_size_count(void *p, lfs_block_t block) {
(void)block;
lfs_size_t *size = p;
*size += 1;
return 0;
}
lfs_ssize_t lfs_fs_size(lfs_t *lfs) {
lfs_size_t size = 0;
int err = lfs_fs_traverse(lfs, lfs_fs_size_count, &size);
if (err) {
return err;
}
return size;
}
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