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67cf4e10f430c9c6463e1c7f0a09cc7748e97091
thirdparty-littlefs/lfs.c
Christopher Haster 67cf4e10f4 WIP fixed several TODOs
2018-08-01 06:43:46 -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 int lfs_cache_read(lfs_t *lfs, lfs_cache_t *rcache,
const lfs_cache_t *pcache, lfs_block_t block,
lfs_off_t off, void *buffer, lfs_size_t size) {
uint8_t *data = buffer;
LFS_ASSERT(block != 0xffffffff);
while (size > 0) {
if (pcache && block == pcache->block && off >= pcache->off &&
off < pcache->off + lfs->cfg->prog_size) {
// is already in pcache?
lfs_size_t diff = lfs_min(size,
lfs->cfg->prog_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 + lfs->cfg->read_size) {
// is already in rcache?
lfs_size_t diff = lfs_min(size,
lfs->cfg->read_size - (off-rcache->off));
memcpy(data, &rcache->buffer[off-rcache->off], diff);
data += diff;
off += diff;
size -= diff;
continue;
}
if (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 = off - (off % lfs->cfg->read_size);
int err = lfs->cfg->read(lfs->cfg, rcache->block,
rcache->off, rcache->buffer, lfs->cfg->read_size);
if (err) {
return err;
}
}
return 0;
}
static int lfs_cache_cmp(lfs_t *lfs, lfs_cache_t *rcache,
const lfs_cache_t *pcache, 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 c;
int err = lfs_cache_read(lfs, rcache, pcache,
block, off+i, &c, 1);
if (err) {
return err;
}
if (c != data[i]) {
return false;
}
}
return true;
}
static int lfs_cache_crc(lfs_t *lfs, lfs_cache_t *rcache,
const lfs_cache_t *pcache, 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 = lfs_cache_read(lfs, rcache, pcache,
block, off+i, &c, 1);
if (err) {
return err;
}
lfs_crc(crc, &c, 1);
}
return 0;
}
static int lfs_cache_flush(lfs_t *lfs,
lfs_cache_t *pcache, lfs_cache_t *rcache) {
if (pcache->block != 0xffffffff) {
LFS_ASSERT(pcache->block < lfs->cfg->block_count);
int err = lfs->cfg->prog(lfs->cfg, pcache->block,
pcache->off, pcache->buffer, lfs->cfg->prog_size);
if (err) {
return err;
}
if (rcache) {
int res = lfs_cache_cmp(lfs, rcache, NULL, pcache->block,
pcache->off, pcache->buffer, lfs->cfg->prog_size);
if (res < 0) {
return res;
}
if (!res) {
return LFS_ERR_CORRUPT;
}
}
pcache->block = 0xffffffff;
}
return 0;
}
static int lfs_cache_prog(lfs_t *lfs, lfs_cache_t *pcache,
lfs_cache_t *rcache, 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->prog_size) {
// is already in pcache?
lfs_size_t diff = lfs_min(size,
lfs->cfg->prog_size - (off-pcache->off));
memcpy(&pcache->buffer[off-pcache->off], data, diff);
data += diff;
off += diff;
size -= diff;
if (off % lfs->cfg->prog_size == 0) {
// eagerly flush out pcache if we fill up
int err = lfs_cache_flush(lfs, pcache, rcache);
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);
if (off % lfs->cfg->prog_size == 0 &&
size >= lfs->cfg->prog_size) {
// bypass pcache?
LFS_ASSERT(block < lfs->cfg->block_count);
lfs_size_t diff = size - (size % lfs->cfg->prog_size);
int err = lfs->cfg->prog(lfs->cfg, block, off, data, diff);
if (err) {
return err;
}
if (rcache) {
int res = lfs_cache_cmp(lfs, rcache, NULL,
block, off, data, diff);
if (res < 0) {
return res;
}
if (!res) {
return LFS_ERR_CORRUPT;
}
}
data += diff;
off += diff;
size -= diff;
continue;
}
// prepare pcache, first condition can no longer fail
pcache->block = block;
pcache->off = off - (off % lfs->cfg->prog_size);
}
return 0;
}
/// General lfs block device operations ///
static int lfs_bd_read(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, void *buffer, lfs_size_t size) {
return lfs_cache_read(lfs, &lfs->rcache, &lfs->pcache,
block, off, buffer, size);
}
static int lfs_bd_prog(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, const void *buffer, lfs_size_t size) {
return lfs_cache_prog(lfs, &lfs->pcache, NULL,
block, off, buffer, size);
}
static int lfs_bd_cmp(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, const void *buffer, lfs_size_t size) {
return lfs_cache_cmp(lfs, &lfs->rcache, NULL, block, off, buffer, size);
}
static int lfs_bd_crc(lfs_t *lfs, lfs_block_t block,
lfs_off_t off, lfs_size_t size, uint32_t *crc) {
return lfs_cache_crc(lfs, &lfs->rcache, NULL, block, off, size, crc);
}
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);
}
static int lfs_bd_sync(lfs_t *lfs) {
lfs->rcache.block = 0xffffffff;
int err = lfs_cache_flush(lfs, &lfs->pcache, NULL);
if (err) {
return err;
}
return lfs->cfg->sync(lfs->cfg);
}
/// Internal operations predeclared here ///
static int lfs_fs_pred(lfs_t *lfs, const lfs_block_t dir[2],
lfs_mdir_t *pdir);
static int32_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_scan(lfs_t *lfs);
static int lfs_fs_forceconsistency(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 %d", 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 inline void lfs_pairswap(lfs_block_t pair[2]) {
lfs_block_t t = pair[0];
pair[0] = pair[1];
pair[1] = t;
}
static inline bool lfs_pairisnull(const lfs_block_t pair[2]) {
return pair[0] == 0xffffffff || pair[1] == 0xffffffff;
}
static inline int lfs_paircmp(
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_pairsync(
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_pairfromle32(lfs_block_t *pair) {
pair[0] = lfs_fromle32(pair[0]);
pair[1] = lfs_fromle32(pair[1]);
}
static inline void lfs_pairtole32(lfs_block_t *pair) {
pair[0] = lfs_tole32(pair[0]);
pair[1] = lfs_tole32(pair[1]);
}
static void lfs_ctzfromle32(struct lfs_ctz *ctz) {
ctz->head = lfs_fromle32(ctz->head);
ctz->size = lfs_fromle32(ctz->size);
}
static void lfs_ctztole32(struct lfs_ctz *ctz) {
ctz->head = lfs_tole32(ctz->head);
ctz->size = lfs_tole32(ctz->size);
}
/// Entry tag operations ///
#define LFS_MKTAG(type, id, size) \
(((uint32_t)(type) << 22) | ((uint32_t)(id) << 12) | (uint32_t)(size))
#define LFS_MKATTR(type, id, buffer, size, next) \
&(const lfs_mattr_t){LFS_MKTAG(type, id, size), (buffer), (next)}
static inline bool lfs_tagisvalid(uint32_t tag) {
return !(tag & 0x80000000);
}
static inline bool lfs_tagisuser(uint32_t tag) {
return (tag & 0x40000000);
}
static inline uint16_t lfs_tagtype(uint32_t tag) {
return (tag & 0x7fc00000) >> 22;
}
static inline uint16_t lfs_tagsubtype(uint32_t tag) {
return (tag & 0x7c000000) >> 22;
}
static inline uint16_t lfs_tagid(uint32_t tag) {
return (tag & 0x003ff000) >> 12;
}
static inline lfs_size_t lfs_tagsize(uint32_t tag) {
return tag & 0x00000fff;
}
// operations on set of globals
static inline void lfs_globalxor(lfs_global_t *a, const lfs_global_t *b) {
for (int i = 0; i < sizeof(lfs_global_t)/2; i++) {
a->u16[i] ^= b->u16[i];
}
}
static inline bool lfs_globaliszero(const lfs_global_t *a) {
for (int i = 0; i < sizeof(lfs_global_t)/2; i++) {
if (a->u16[i] != 0) {
return false;
}
}
return true;
}
static inline void lfs_globalzero(lfs_global_t *a) {
memset(a->u16, 0x00, sizeof(lfs_global_t));
}
static inline void lfs_globalones(lfs_global_t *a) {
memset(a->u16, 0xff, sizeof(lfs_global_t));
}
static inline void lfs_globalxormove(lfs_global_t *a,
const lfs_block_t pair[2], uint16_t id) {
a->u16[0] ^= id;
for (int i = 0; i < sizeof(lfs_block_t[2])/2; i++) {
a->u16[1+i] ^= ((uint16_t*)pair)[i];
}
}
static inline void lfs_globalxordeorphaned(lfs_global_t *a, bool deorphaned) {
a->u16[0] ^= deorphaned << 15;
}
static inline void lfs_globalfromle32(lfs_global_t *a) {
a->u16[0] = lfs_fromle16(a->u16[0]);
lfs_pairfromle32((lfs_block_t*)&a->u16[1]);
}
static inline void lfs_globaltole32(lfs_global_t *a) {
a->u16[0] = lfs_tole16(a->u16[0]);
lfs_pairtole32((lfs_block_t*)&a->u16[1]);
}
static inline const lfs_block_t *lfs_globalmovepair(const lfs_t *lfs) {
return (const lfs_block_t*)&lfs->globals.u16[1];
}
static inline uint16_t lfs_globalmoveid(const lfs_t *lfs) {
return 0x3ff & lfs->globals.u16[0];
}
static inline bool lfs_globalisdeorphaned(const lfs_t *lfs) {
return 0x8000 & lfs->globals.u16[0];
}
static inline void lfs_globalmove(lfs_t *lfs,
const lfs_block_t pair[2], uint16_t id) {
lfs_global_t diff;
lfs_globalzero(&diff);
lfs_globalxormove(&diff, lfs_globalmovepair(lfs), lfs_globalmoveid(lfs));
lfs_globalxormove(&diff, pair, id);
lfs_globalfromle32(&lfs->locals);
lfs_globalxor(&lfs->locals, &diff);
lfs_globaltole32(&lfs->locals);
lfs_globalxor(&lfs->globals, &diff);
}
static inline void lfs_globaldeorphaned(lfs_t *lfs, bool deorphaned) {
deorphaned ^= lfs_globalisdeorphaned(lfs);
lfs_globalfromle32(&lfs->locals);
lfs_globalxordeorphaned(&lfs->locals, deorphaned);
lfs_globaltole32(&lfs->locals);
lfs_globalxordeorphaned(&lfs->globals, deorphaned);
}
// commit logic
struct lfs_commit {
lfs_block_t block;
lfs_off_t off;
uint32_t ptag;
uint32_t crc;
lfs_off_t begin;
lfs_off_t end;
};
struct lfs_diskoff {
lfs_block_t block;
lfs_off_t off;
};
static int32_t lfs_commitget(lfs_t *lfs, lfs_block_t block, lfs_off_t off,
uint32_t tag, uint32_t getmask, uint32_t gettag, int32_t getdiff,
void *buffer, bool stopatcommit) {
// iterate over dir block backwards (for faster lookups)
while (off >= 2*sizeof(tag)+lfs_tagsize(tag)) {
off -= sizeof(tag)+lfs_tagsize(tag);
if (lfs_tagtype(tag) == LFS_TYPE_CRC && stopatcommit) {
break;
} else if (lfs_tagtype(tag) == LFS_TYPE_DELETE) {
if (lfs_tagid(tag) <= lfs_tagid(gettag + getdiff)) {
getdiff += LFS_MKTAG(0, 1, 0);
}
} else if ((tag & getmask) == ((gettag + getdiff) & getmask)) {
if (buffer) {
lfs_size_t diff = lfs_min(
lfs_tagsize(gettag), lfs_tagsize(tag));
int err = lfs_bd_read(lfs, block,
off+sizeof(tag), buffer, diff);
if (err) {
return err;
}
memset((uint8_t*)buffer + diff, 0,
lfs_tagsize(gettag) - diff);
}
return tag - getdiff;
}
uint32_t ntag;
int err = lfs_bd_read(lfs, block, off, &ntag, sizeof(ntag));
if (err) {
return err;
}
tag ^= lfs_fromle32(ntag);
}
return LFS_ERR_NOENT;
}
static int lfs_commitattrs(lfs_t *lfs, struct lfs_commit *commit,
uint16_t id, const struct lfs_attr *attrs);
static int lfs_commitmove(lfs_t *lfs, struct lfs_commit *commit,
uint16_t fromid, uint16_t toid,
const lfs_mdir_t *dir, const lfs_mattr_t *attrs);
static int lfs_commitattr(lfs_t *lfs, struct lfs_commit *commit,
uint32_t tag, const void *buffer) {
if (lfs_tagtype(tag) == LFS_FROM_ATTRS) {
// special case for custom attributes
return lfs_commitattrs(lfs, commit,
lfs_tagid(tag), buffer);
} else if (lfs_tagtype(tag) == LFS_FROM_MOVE) {
// special case for moves
return lfs_commitmove(lfs, commit,
lfs_tagsize(tag), lfs_tagid(tag),
buffer, NULL);
}
// check if we fit
lfs_size_t size = lfs_tagsize(tag);
if (commit->off + sizeof(tag)+size > commit->end) {
return LFS_ERR_NOSPC;
}
// write out tag
uint32_t ntag = lfs_tole32((tag & 0x7fffffff) ^ commit->ptag);
lfs_crc(&commit->crc, &ntag, sizeof(ntag));
int err = lfs_bd_prog(lfs, commit->block, commit->off,
&ntag, sizeof(ntag));
if (err) {
return err;
}
commit->off += sizeof(ntag);
if (!(tag & 0x80000000)) {
// from memory
lfs_crc(&commit->crc, buffer, size);
err = lfs_bd_prog(lfs, commit->block, commit->off, buffer, size);
if (err) {
return err;
}
} else {
// from disk
const struct lfs_diskoff *disk = buffer;
for (lfs_off_t i = 0; i < size; i++) {
// rely on caching to make this efficient
uint8_t dat;
int err = lfs_bd_read(lfs, disk->block, disk->off+i, &dat, 1);
if (err) {
return err;
}
lfs_crc(&commit->crc, &dat, 1);
err = lfs_bd_prog(lfs, commit->block, commit->off+i, &dat, 1);
if (err) {
return err;
}
}
}
commit->off += size;
commit->ptag = tag & 0x7fffffff;
return 0;
}
static int lfs_commitattrs(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_commitattr(lfs, commit,
LFS_MKTAG(0x100 | a->type, id, a->size), a->buffer);
if (err) {
return err;
}
}
return 0;
}
static int lfs_commitmove(lfs_t *lfs, struct lfs_commit *commit,
uint16_t fromid, uint16_t toid,
const lfs_mdir_t *dir, const lfs_mattr_t *attrs) {
// iterate through list and commits, only committing unique entries
lfs_off_t off = dir->off;
uint32_t ntag = dir->etag;
while (attrs || off > sizeof(uint32_t)) {
struct lfs_diskoff disk;
uint32_t tag;
const void *buffer;
if (attrs) {
tag = attrs->tag;
buffer = attrs->buffer;
attrs = attrs->next;
} else {
LFS_ASSERT(off > sizeof(ntag)+lfs_tagsize(ntag));
off -= sizeof(ntag)+lfs_tagsize(ntag);
tag = ntag;
buffer = &disk;
disk.block = dir->pair[0];
disk.off = off + sizeof(tag);
int err = lfs_bd_read(lfs, dir->pair[0], off, &ntag, sizeof(ntag));
if (err) {
return err;
}
ntag = lfs_fromle32(ntag);
ntag ^= tag;
tag |= 0x80000000;
}
if (lfs_tagtype(tag) == LFS_TYPE_DELETE && lfs_tagid(tag) <= fromid) {
// something was deleted, we need to move around it
fromid += 1;
} else if (lfs_tagid(tag) != fromid) {
// ignore non-matching ids
} else {
// check if type has already been committed
int32_t res = lfs_commitget(lfs, commit->block,
commit->off, commit->ptag,
lfs_tagisuser(tag) ? 0x7ffff000 : 0x7c3ff000,
LFS_MKTAG(lfs_tagtype(tag), toid, 0),
0, NULL, true);
if (res < 0 && res != LFS_ERR_NOENT) {
return res;
}
if (res == LFS_ERR_NOENT) {
// update id and commit, as we are currently unique
int err = lfs_commitattr(lfs, commit,
(tag & 0xffc00fff) | LFS_MKTAG(0, toid, 0),
buffer);
if (err) {
return err;
}
}
}
}
return 0;
}
static int lfs_commitglobals(lfs_t *lfs, struct lfs_commit *commit,
lfs_global_t *locals) {
if (lfs_globaliszero(&lfs->locals)) {
return 0;
}
lfs_globalxor(locals, &lfs->locals);
int err = lfs_commitattr(lfs, commit,
LFS_MKTAG(LFS_TYPE_GLOBALS, 0x3ff, sizeof(lfs_global_t)), locals);
lfs_globalxor(locals, &lfs->locals);
return err;
}
static int lfs_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
// 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
uint32_t tag;
int err = lfs_bd_read(lfs, commit->block, off, &tag, sizeof(tag));
if (err) {
return err;
}
// build crc tag
tag = lfs_fromle32(tag);
tag = (0x80000000 & ~tag) |
LFS_MKTAG(LFS_TYPE_CRC, 0x3ff,
off - (commit->off+sizeof(uint32_t)));
// write out crc
uint32_t footer[2];
footer[0] = lfs_tole32(tag ^ commit->ptag);
lfs_crc(&commit->crc, &footer[0], sizeof(footer[0]));
footer[1] = lfs_tole32(commit->crc);
err = lfs_bd_prog(lfs, commit->block, commit->off, footer, sizeof(footer));
if (err) {
return err;
}
commit->off += sizeof(tag)+lfs_tagsize(tag);
commit->ptag = tag;
// flush buffers
err = lfs_bd_sync(lfs);
if (err) {
return err;
}
// successful commit, check checksum to make sure
uint32_t crc = 0xffffffff;
err = lfs_bd_crc(lfs, commit->block, commit->begin,
commit->off-lfs_tagsize(tag)-commit->begin, &crc);
if (err) {
return err;
}
if (crc != commit->crc) {
return LFS_ERR_CORRUPT;
}
return 0;
}
// internal dir operations
static int lfs_dir_alloc(lfs_t *lfs, lfs_mdir_t *dir,
bool split, const lfs_block_t tail[2]) {
// allocate pair of dir blocks (backwards, so we write to 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, dir->pair[0], 0, &dir->rev, 4);
dir->rev = lfs_fromle32(dir->rev);
if (err) {
return err;
}
// set defaults
dir->off = sizeof(dir->rev);
dir->etag = 0;
dir->count = 0;
dir->tail[0] = tail[0];
dir->tail[1] = tail[1];
dir->erased = false;
dir->split = split;
lfs_globalzero(&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 lfs_mattr_t *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_globalxor(&lfs->locals, &dir->locals);
lfs_globalzero(&dir->locals);
// increment revision count
dir->rev += 1;
while (true) {
// last complete id
int16_t ack = -1;
dir->count = end - begin;
if (true) {
// 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 crc = 0xffffffff;
uint32_t rev = lfs_tole32(dir->rev);
lfs_crc(&crc, &rev, sizeof(rev));
err = lfs_bd_prog(lfs, dir->pair[1], 0, &rev, sizeof(rev));
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
// setup compaction
struct lfs_commit commit = {
.block = dir->pair[1],
.off = sizeof(dir->rev),
.crc = crc,
.ptag = 0,
// space is complicated, we need room for tail, crc, globals,
// and we cap at half a block to give room for metadata updates
.begin = 0,
.end = lfs_min(
lfs_alignup(lfs->cfg->block_size/2, lfs->cfg->prog_size),
lfs->cfg->block_size - 34),
};
// commit with a move
for (uint16_t id = begin; id < end; id++) {
err = lfs_commitmove(lfs, &commit,
id, id - begin, source, attrs);
if (err) {
if (err == LFS_ERR_NOSPC) {
goto split;
} else if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
ack = id;
}
// reopen reserved space at the end
commit.end = lfs->cfg->block_size - 8;
if (!relocated) {
err = lfs_commitglobals(lfs, &commit, &dir->locals);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
}
if (!lfs_pairisnull(dir->tail)) {
// commit tail, which may be new after last size check
lfs_pairtole32(dir->tail);
err = lfs_commitattr(lfs, &commit,
LFS_MKTAG(LFS_TYPE_TAIL + dir->split,
0x3ff, sizeof(dir->tail)), dir->tail);
lfs_pairfromle32(dir->tail);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
}
err = lfs_commitcrc(lfs, &commit);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
// successful compaction, swap dir pair to indicate most recent
lfs_pairswap(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
lfs->pcache.block = 0xffffffff;
if (ack == -1) {
// If we can't fit in this block, we won't fit in next block
return LFS_ERR_NOSPC;
}
lfs_mdir_t tail;
int err = lfs_dir_alloc(lfs, &tail, dir->split, dir->tail);
if (err) {
return err;
}
err = lfs_dir_compact(lfs, &tail, attrs, dir, ack+1, end);
if (err) {
return err;
}
end = ack+1;
dir->tail[0] = tail.pair[0];
dir->tail[1] = tail.pair[1];
dir->split = true;
continue;
relocate:
//commit was corrupted
LFS_DEBUG("Bad block at %d", dir->pair[1]);
// drop caches and prepare to relocate block
relocated = true;
lfs->pcache.block = 0xffffffff;
// can't relocate superblock, filesystem is now frozen
if (lfs_paircmp(oldpair, (const lfs_block_t[2]){0, 1}) == 0) {
LFS_WARN("Superblock %d has become unwritable", oldpair[1]);
return LFS_ERR_CORRUPT;
}
// relocate half of pair
err = lfs_alloc(lfs, &dir->pair[1]);
if (err) {
return err;
}
continue;
}
if (!relocated) {
// successful commit, update globals
lfs_globalxor(&dir->locals, &lfs->locals);
lfs_globalzero(&lfs->locals);
} else {
// update references if we relocated
LFS_DEBUG("Relocating %d %d to %d %d",
oldpair[0], oldpair[1], dir->pair[0], dir->pair[1]);
int err = lfs_fs_relocate(lfs, oldpair, dir->pair);
if (err) {
return err;
}
}
// update any dirs/files that are affected
for (int i = 0; i < 2; i++) {
for (lfs_file_t *f = ((lfs_file_t**)&lfs->files)[i]; f; f = f->next) {
if (lfs_paircmp(f->pair, dir->pair) == 0 &&
f->id >= begin && f->id < end) {
f->pair[0] = dir->pair[0];
f->pair[1] = dir->pair[1];
f->id -= begin;
}
}
}
return 0;
}
static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
const lfs_mattr_t *attrs) {
lfs_mattr_t cancelattr;
lfs_global_t canceldiff;
lfs_globalzero(&canceldiff);
if (lfs_paircmp(dir->pair, lfs_globalmovepair(lfs)) == 0) {
// Wait, we have the move? Just cancel this out here
// We need to, or else the move can become outdated
lfs_globalxormove(&canceldiff,
lfs_globalmovepair(lfs), lfs_globalmoveid(lfs));
lfs_globalxormove(&canceldiff,
(lfs_block_t[2]){0xffffffff, 0xffffffff}, 0x3ff);
lfs_globalfromle32(&lfs->locals);
lfs_globalxor(&lfs->locals, &canceldiff);
lfs_globaltole32(&lfs->locals);
cancelattr.tag = LFS_MKTAG(LFS_TYPE_DELETE, lfs_globalmoveid(lfs), 0);
cancelattr.next = attrs;
attrs = &cancelattr;
}
// calculate new directory size
uint32_t deletetag = 0xffffffff;
for (const lfs_mattr_t *a = attrs; a; a = a->next) {
if (lfs_tagid(a->tag) < 0x3ff && lfs_tagid(a->tag) >= dir->count) {
dir->count = lfs_tagid(a->tag)+1;
}
if (lfs_tagtype(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_globalxor(&lfs->locals, &dir->locals);
return lfs_dir_commit(lfs, &pdir,
LFS_MKATTR(LFS_TYPE_TAIL + pdir.split, 0x3ff,
pdir.tail, sizeof(pdir.tail),
NULL));
}
}
}
}
if (!dir->erased) {
compact:
// fall back to compaction
lfs->pcache.block = 0xffffffff;
int err = lfs_dir_compact(lfs, dir, attrs, dir, 0, dir->count);
if (err) {
return err;
}
} else {
// 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,
};
for (const lfs_mattr_t *a = attrs; a; a = a->next) {
if (lfs_tagtype(a->tag) != LFS_TYPE_DELETE) {
lfs_pairtole32(dir->tail);
int err = lfs_commitattr(lfs, &commit, a->tag, a->buffer);
lfs_pairfromle32(dir->tail);
if (err) {
if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
goto compact;
}
return err;
}
}
}
if (lfs_tagisvalid(deletetag)) {
// special case for deletes, since order matters
int err = lfs_commitattr(lfs, &commit, deletetag, NULL);
if (err) {
if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
goto compact;
}
return err;
}
}
int err = lfs_commitglobals(lfs, &commit, &dir->locals);
if (err) {
if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
goto compact;
}
return err;
}
err = lfs_commitcrc(lfs, &commit);
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_globalxor(&dir->locals, &lfs->locals);
lfs_globalzero(&lfs->locals);
}
// update globals that are affected
lfs_globalxor(&lfs->globals, &canceldiff);
// update any directories that are affected
for (lfs_dir_t *d = lfs->dirs; d; d = d->next) {
if (lfs_paircmp(d->m.pair, dir->pair) == 0) {
d->m = *dir;
if (d->id > lfs_tagid(deletetag)) {
d->pos -= 1;
}
}
}
for (int i = 0; i < 2; i++) {
for (lfs_file_t *f = ((lfs_file_t**)&lfs->files)[i]; f; f = f->next) {
if (f->id == lfs_tagid(deletetag)) {
f->pair[0] = 0xffffffff;
f->pair[1] = 0xffffffff;
} else if (f->id > lfs_tagid(deletetag)) {
f->id -= 1;
}
}
}
return 0;
}
static int32_t lfs_dir_find(lfs_t *lfs,
lfs_mdir_t *dir, const lfs_block_t pair[2],
uint32_t findmask, uint32_t findtag,
const void *findbuffer) {
dir->pair[0] = pair[0];
dir->pair[1] = pair[1];
int32_t foundtag = LFS_ERR_NOENT;
// find the block with the most recent revision
uint32_t rev[2];
for (int i = 0; i < 2; i++) {
int err = lfs_bd_read(lfs, dir->pair[i], 0, &rev[i], sizeof(rev[i]));
if (err) {
return err;
}
rev[i] = lfs_fromle32(rev[i]);
}
if (lfs_scmp(rev[1], rev[0]) > 0) {
lfs_pairswap(dir->pair);
lfs_pairswap(rev);
}
// load blocks and check crc
for (int i = 0; i < 2; i++) {
lfs_off_t off = sizeof(dir->rev);
uint32_t ptag = 0;
uint32_t crc = 0xffffffff;
dir->rev = lfs_tole32(rev[0]);
lfs_crc(&crc, &dir->rev, sizeof(dir->rev));
dir->rev = lfs_fromle32(dir->rev);
dir->off = 0;
uint32_t tempfoundtag = foundtag;
uint16_t tempcount = 0;
lfs_block_t temptail[2] = {0xffffffff, 0xffffffff};
bool tempsplit = false;
lfs_global_t templocals;
lfs_globalzero(&templocals);
while (true) {
// extract next tag
uint32_t tag;
int err = lfs_bd_read(lfs, dir->pair[0],
off, &tag, sizeof(tag));
if (err) {
return err;
}
lfs_crc(&crc, &tag, sizeof(tag));
tag = lfs_fromle32(tag) ^ ptag;
// next commit not yet programmed
if (lfs_tagtype(ptag) == LFS_TYPE_CRC && !lfs_tagisvalid(tag)) {
dir->erased = true;
break;
}
// check we're in valid range
if (off + sizeof(tag)+lfs_tagsize(tag) > lfs->cfg->block_size) {
dir->erased = false;
break;
}
if (lfs_tagtype(tag) == LFS_TYPE_CRC) {
// check the crc attr
uint32_t dcrc;
int err = lfs_bd_read(lfs, dir->pair[0],
off+sizeof(tag), &dcrc, sizeof(dcrc));
if (err) {
return err;
}
dcrc = lfs_fromle32(dcrc);
if (crc != dcrc) {
dir->erased = false;
break;
}
foundtag = tempfoundtag;
dir->off = off + sizeof(tag)+lfs_tagsize(tag);
dir->etag = tag;
dir->count = tempcount;
dir->tail[0] = temptail[0];
dir->tail[1] = temptail[1];
dir->split = tempsplit;
dir->locals = templocals;
crc = 0xffffffff;
} else {
err = lfs_bd_crc(lfs, dir->pair[0],
off+sizeof(tag), lfs_tagsize(tag), &crc);
if (err) {
return err;
}
if (lfs_tagid(tag) < 0x3ff && lfs_tagid(tag) >= tempcount) {
tempcount = lfs_tagid(tag)+1;
}
if (lfs_tagsubtype(tag) == LFS_TYPE_TAIL) {
tempsplit = (lfs_tagtype(tag) & 1);
err = lfs_bd_read(lfs, dir->pair[0], off+sizeof(tag),
temptail, sizeof(temptail));
if (err) {
return err;
}
lfs_pairfromle32(temptail);
} else if (lfs_tagsubtype(tag) == LFS_TYPE_GLOBALS) {
err = lfs_bd_read(lfs, dir->pair[0], off+sizeof(tag),
&templocals, sizeof(templocals));
if (err) {
return err;
}
} else if (lfs_tagsubtype(tag) == LFS_TYPE_DELETE) {
LFS_ASSERT(tempcount > 0);
tempcount -= 1;
if (lfs_tagid(tag) == lfs_tagid(tempfoundtag)) {
tempfoundtag = LFS_ERR_NOENT;
} else if (lfs_tagisvalid(tempfoundtag) &&
lfs_tagid(tag) < lfs_tagid(tempfoundtag)) {
tempfoundtag -= LFS_MKTAG(0, 1, 0);
}
} else if ((tag & findmask) == (findtag & findmask)) {
int res = lfs_bd_cmp(lfs, dir->pair[0], off+sizeof(tag),
findbuffer, lfs_tagsize(tag));
if (res < 0) {
return res;
}
if (res) {
// found a match
tempfoundtag = tag;
}
}
}
ptag = tag;
off += sizeof(tag)+lfs_tagsize(tag);
}
// consider what we have good enough
if (dir->off > 0) {
// synthetic move
if (lfs_paircmp(dir->pair, lfs_globalmovepair(lfs)) == 0) {
if (lfs_globalmoveid(lfs) == lfs_tagid(foundtag)) {
foundtag = LFS_ERR_NOENT;
} else if (lfs_tagisvalid(foundtag) &&
lfs_globalmoveid(lfs) < lfs_tagid(foundtag)) {
foundtag -= LFS_MKTAG(0, 1, 0);
}
}
return foundtag;
}
// failed, try the other crc?
lfs_pairswap(dir->pair);
lfs_pairswap(rev);
}
LFS_ERROR("Corrupted dir pair at %d %d", 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]) {
int32_t res = lfs_dir_find(lfs, dir, pair, 0xffffffff, 0xffffffff, NULL);
if (res < 0 && res != LFS_ERR_NOENT) {
return res;
}
return 0;
}
static int32_t lfs_dir_get(lfs_t *lfs, lfs_mdir_t *dir,
uint32_t getmask, uint32_t gettag, void *buffer) {
int32_t getdiff = 0;
if (lfs_paircmp(dir->pair, lfs_globalmovepair(lfs)) == 0 &&
lfs_tagid(gettag) <= lfs_globalmoveid(lfs)) {
// synthetic moves
getdiff = LFS_MKTAG(0, 1, 0);
}
return lfs_commitget(lfs, dir->pair[0], dir->off, dir->etag,
getmask, gettag, getdiff, buffer, false);
}
static int32_t lfs_dir_lookup(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
int32_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_tagtype(tag) != LFS_TYPE_DIR) {
return LFS_ERR_NOTDIR;
}
// grab the entry data
if (lfs_tagid(tag) != 0x3ff) {
int32_t res = lfs_dir_get(lfs, dir, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tagid(tag), 8), pair);
if (res < 0) {
return res;
}
lfs_pairfromle32(pair);
}
// find entry matching name
while (true) {
tag = lfs_dir_find(lfs, dir, pair, 0x7c000fff,
LFS_MKTAG(LFS_TYPE_NAME, 0, namelen), name);
if (tag < 0 && tag != LFS_ERR_NOENT) {
return tag;
}
if (tag != LFS_ERR_NOENT) {
// found it
break;
}
if (!dir->split) {
// couldn't find it
return LFS_ERR_NOENT;
}
pair[0] = dir->tail[0];
pair[1] = dir->tail[1];
}
// 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;
}
int32_t tag = lfs_dir_get(lfs, dir, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_NAME, id, lfs->name_size+1), info->name);
if (tag < 0) {
return tag;
}
info->type = lfs_tagtype(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_ctzfromle32(&ctz);
if (lfs_tagtype(tag) == LFS_TYPE_CTZSTRUCT) {
info->size = ctz.size;
} else if (lfs_tagtype(tag) == LFS_TYPE_INLINESTRUCT) {
info->size = lfs_tagsize(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;
int32_t res = lfs_dir_lookup(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_size) {
return LFS_ERR_NAMETOOLONG;
}
// build up new directory
lfs_alloc_ack(lfs);
lfs_mdir_t dir;
err = lfs_dir_alloc(lfs, &dir, false, cwd.tail);
if (err) {
return err;
}
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_pairtole32(dir.pair);
err = lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(LFS_TYPE_DIR, id, path, nlen,
LFS_MKATTR(LFS_TYPE_DIRSTRUCT, id, dir.pair, sizeof(dir.pair),
LFS_MKATTR(LFS_TYPE_SOFTTAIL, 0x3ff, cwd.tail, sizeof(cwd.tail),
NULL))));
lfs_pairfromle32(dir.pair);
if (err) {
return err;
}
return 0;
}
int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
int32_t tag = lfs_dir_lookup(lfs, &dir->m, &path);
if (tag < 0) {
return tag;
}
if (lfs_tagtype(tag) != LFS_TYPE_DIR) {
return LFS_ERR_NOTDIR;
}
lfs_block_t pair[2];
if (lfs_tagid(tag) == 0x3ff) {
// handle root dir separately
pair[0] = lfs->root[0];
pair[1] = lfs->root[1];
} else {
// get dir pair from parent
int32_t res = lfs_dir_get(lfs, &dir->m, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tagid(tag), 8), pair);
if (res < 0) {
return res;
}
lfs_pairfromle32(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 directories
dir->next = lfs->dirs;
lfs->dirs = dir;
return 0;
}
int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir) {
// remove from list of directories
for (lfs_dir_t **p = &lfs->dirs; *p; p = &(*p)->next) {
if (*p == dir) {
*p = dir->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;
}
int 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_ctzindex(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_ctzfind(lfs_t *lfs,
lfs_cache_t *rcache, const lfs_cache_t *pcache,
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_ctzindex(lfs, &(lfs_off_t){size-1});
lfs_off_t target = lfs_ctzindex(lfs, &pos);
while (current > target) {
lfs_size_t skip = lfs_min(
lfs_npw2(current-target+1) - 1,
lfs_ctz(current));
int err = lfs_cache_read(lfs, rcache, pcache, head, 4*skip, &head, 4);
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_ctzextend(lfs_t *lfs,
lfs_cache_t *rcache, lfs_cache_t *pcache,
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);
if (true) {
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_ctzindex(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_cache_read(lfs, rcache, NULL,
head, i, &data, 1);
if (err) {
return err;
}
err = lfs_cache_prog(lfs, pcache, rcache,
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_cache_prog(lfs, pcache, rcache,
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_cache_read(lfs, rcache, NULL,
head, 4*i, &head, 4);
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 %d", nblock);
// just clear cache and try a new block
pcache->block = 0xffffffff;
}
}
static int lfs_ctztraverse(lfs_t *lfs,
lfs_cache_t *rcache, const lfs_cache_t *pcache,
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_ctzindex(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_cache_read(lfs, rcache, pcache, head, 0, &heads, count*4);
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;
}
}
// allocate entry for file if it doesn't exist
lfs_mdir_t cwd;
int32_t tag = lfs_dir_lookup(lfs, &cwd, &path);
if (tag < 0 && !(tag == LFS_ERR_NOENT && path)) {
return tag;
}
if (tag == LFS_ERR_NOENT) {
if (!(flags & LFS_O_CREAT)) {
return LFS_ERR_NOENT;
}
// check that name fits
lfs_size_t nlen = strlen(path);
if (nlen > lfs->name_size) {
return LFS_ERR_NAMETOOLONG;
}
// get next slot and create entry to remember name
// TODO do we need to make file registered to list to catch updates from this commit? ie if id/cwd change
uint16_t id = cwd.count;
int err = lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(LFS_TYPE_REG, id, path, nlen,
LFS_MKATTR(LFS_TYPE_INLINESTRUCT, id, NULL, 0,
NULL)));
if (err) {
return err;
}
// TODO should we be catching this here?
if (id >= cwd.count) {
// catch updates from a compact in the above commit
id -= cwd.count;
cwd.pair[0] = cwd.tail[0];
cwd.pair[1] = cwd.tail[1];
}
tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, id, 0);
} else if (flags & LFS_O_EXCL) {
return LFS_ERR_EXIST;
} else if (lfs_tagtype(tag) != LFS_TYPE_REG) {
return LFS_ERR_ISDIR;
} else if (flags & LFS_O_TRUNC) {
// truncate if requested
tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, lfs_tagid(tag), 0);
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, &cwd, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tagid(tag), 8), &file->ctz);
if (tag < 0) {
return tag;
}
lfs_ctzfromle32(&file->ctz);
}
// setup file struct
file->cfg = cfg;
file->pair[0] = cwd.pair[0];
file->pair[1] = cwd.pair[1];
file->id = lfs_tagid(tag);
file->flags = flags;
file->pos = 0;
// fetch attrs
for (const struct lfs_attr *a = file->cfg->attrs; a; a = a->next) {
if ((file->flags & 3) != LFS_O_WRONLY) {
// TODO what if cwd is invalid from above compact?
int32_t res = lfs_dir_get(lfs, &cwd, 0x7ffff000,
LFS_MKTAG(0x100 | a->type, file->id, a->size), a->buffer);
if (res < 0 && res != LFS_ERR_NOENT) {
return res;
}
}
if ((file->flags & 3) != LFS_O_RDONLY) {
if (a->size > lfs->attr_size) {
return LFS_ERR_NOSPC;
}
file->flags |= LFS_F_DIRTY;
}
}
// allocate buffer if needed
file->cache.block = 0xffffffff;
if (file->cfg->buffer) {
file->cache.buffer = file->cfg->buffer;
} else if ((file->flags & 3) == LFS_O_RDONLY) {
file->cache.buffer = lfs_malloc(lfs->cfg->read_size);
if (!file->cache.buffer) {
return LFS_ERR_NOMEM;
}
} else {
file->cache.buffer = lfs_malloc(lfs->cfg->prog_size);
if (!file->cache.buffer) {
return LFS_ERR_NOMEM;
}
}
if (lfs_tagtype(tag) == LFS_TYPE_INLINESTRUCT) {
// load inline files
file->ctz.head = 0xfffffffe;
file->ctz.size = lfs_tagsize(tag);
file->flags |= LFS_F_INLINE;
file->cache.block = file->ctz.head;
file->cache.off = 0;
// don't always read (may be new/trunc file)
if (file->ctz.size > 0) {
int32_t res = lfs_dir_get(lfs, &cwd, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tagid(tag), file->ctz.size),
file->cache.buffer);
if (res < 0) {
lfs_free(file->cache.buffer);
return res;
}
}
}
// add to list of files
file->next = lfs->files;
lfs->files = file;
return 0;
}
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 files
for (lfs_file_t **p = &lfs->files; *p; p = &(*p)->next) {
if (*p == file) {
*p = file->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_cache_read(lfs, &lfs->rcache, &file->cache,
file->block, i, &data, 1);
if (err) {
return err;
}
err = lfs_cache_prog(lfs, &lfs->pcache, &lfs->rcache,
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->prog_size);
file->cache.block = lfs->pcache.block;
file->cache.off = lfs->pcache.off;
lfs->pcache.block = 0xffffffff;
file->block = nblock;
return 0;
relocate:
continue;
}
}
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->rcache.block = 0xffffffff;
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) {
orig.cache.block = 0xffffffff;
lfs->rcache.block = 0xffffffff;
}
}
// write out what we have
while (true) {
int err = lfs_cache_flush(lfs, &file->cache, &lfs->rcache);
if (err) {
if (err == LFS_ERR_CORRUPT) {
goto relocate;
}
return err;
}
break;
relocate:
LFS_DEBUG("Bad block at %d", 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_pairisnull(file->pair)) {
// update dir entry
// TODO keep list of dirs including these guys for no
// need of another reload?
lfs_mdir_t cwd;
err = lfs_dir_fetch(lfs, &cwd, file->pair);
if (err) {
return err;
}
uint16_t type;
const void *buffer;
lfs_size_t size;
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;
buffer = &file->ctz;
size = sizeof(file->ctz);
}
// commit file data and attributes
lfs_ctztole32(&file->ctz);
int err = lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(type, file->id, buffer, size,
LFS_MKATTR(LFS_FROM_ATTRS, file->id, file->cfg->attrs, 0,
NULL)));
lfs_ctzfromle32(&file->ctz);
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_ctzfind(lfs, &file->cache, NULL,
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_cache_read(lfs, &file->cache, NULL,
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_size) {
// 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_ctzfind(lfs, &file->cache, NULL,
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
file->cache.block = 0xffffffff;
}
// extend file with new blocks
lfs_alloc_ack(lfs);
int err = lfs_ctzextend(lfs, &lfs->rcache, &file->cache,
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_cache_prog(lfs, &file->cache, &lfs->rcache,
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_ctzfind(lfs, &file->cache, NULL,
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;
int32_t tag = lfs_dir_lookup(lfs, &cwd, &path);
if (tag < 0) {
return tag;
}
return lfs_dir_getinfo(lfs, &cwd, lfs_tagid(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;
}
int32_t tag = lfs_dir_lookup(lfs, &cwd, &path);
if (tag < 0) {
return tag;
}
lfs_mdir_t dir;
if (lfs_tagtype(tag) == LFS_TYPE_DIR) {
// must be empty before removal
lfs_block_t pair[2];
int32_t res = lfs_dir_get(lfs, &cwd, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, lfs_tagid(tag), 8), pair);
if (res < 0) {
return res;
}
lfs_pairfromle32(pair);
int 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_globaldeorphaned(lfs, false);
}
// delete the entry
err = lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(LFS_TYPE_DELETE, lfs_tagid(tag), NULL, 0,
NULL));
if (err) {
return err;
}
if (lfs_tagtype(tag) == LFS_TYPE_DIR) {
int err = lfs_fs_pred(lfs, dir.pair, &cwd);
if (err) {
return err;
}
// fix orphan
lfs_globaldeorphaned(lfs, true);
// steal state
// TODO test for global state stealing?
cwd.tail[0] = dir.tail[0];
cwd.tail[1] = dir.tail[1];
lfs_globalxor(&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;
int32_t oldtag = lfs_dir_lookup(lfs, &oldcwd, &oldpath);
if (oldtag < 0) {
return oldtag;
}
// find new entry
lfs_mdir_t newcwd;
int32_t prevtag = lfs_dir_lookup(lfs, &newcwd, &newpath);
if (prevtag < 0 && prevtag != LFS_ERR_NOENT) {
return prevtag;
}
uint16_t newid = lfs_tagid(prevtag);
//bool prevexists = (prevtag != LFS_ERR_NOENT);
//bool samepair = (lfs_paircmp(oldcwd.pair, newcwd.pair) == 0);
lfs_mdir_t prevdir;
if (prevtag != LFS_ERR_NOENT) {
// check that we have same type
if (lfs_tagtype(prevtag) != lfs_tagtype(oldtag)) {
return LFS_ERR_ISDIR;
}
if (lfs_tagtype(prevtag) == LFS_TYPE_DIR) {
// must be empty before removal
lfs_block_t prevpair[2];
int32_t res = lfs_dir_get(lfs, &newcwd, 0x7c3ff000,
LFS_MKTAG(LFS_TYPE_STRUCT, newid, 8), prevpair);
if (res < 0) {
return res;
}
lfs_pairfromle32(prevpair);
// must be empty before removal
int 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_globaldeorphaned(lfs, false);
}
} else {
// check that name fits
lfs_size_t nlen = strlen(newpath);
if (nlen > lfs->name_size) {
return LFS_ERR_NAMETOOLONG;
}
// get next id
newid = newcwd.count;
}
// create move to fix later
lfs_globalmove(lfs, oldcwd.pair, lfs_tagid(oldtag));
// move over all attributes
err = lfs_dir_commit(lfs, &newcwd,
LFS_MKATTR(lfs_tagtype(oldtag), newid, newpath, strlen(newpath),
LFS_MKATTR(LFS_FROM_MOVE, newid, &oldcwd, lfs_tagid(oldtag),
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_paircmp(oldcwd.pair, newcwd.pair) != 0) {
err = lfs_dir_commit(lfs, &oldcwd, NULL);
if (err) {
return err;
}
}
if (prevtag != LFS_ERR_NOENT && lfs_tagtype(prevtag) == LFS_TYPE_DIR) {
int err = lfs_fs_pred(lfs, prevdir.pair, &newcwd);
if (err) {
return err;
}
// fix orphan
lfs_globaldeorphaned(lfs, true);
// steal state
// TODO test for global state stealing?
newcwd.tail[0] = prevdir.tail[0];
newcwd.tail[1] = prevdir.tail[1];
lfs_globalxor(&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;
int32_t res = lfs_dir_lookup(lfs, &cwd, &path);
if (res < 0) {
return res;
}
res = lfs_dir_get(lfs, &cwd, 0x7ffff000,
LFS_MKTAG(0x100 | type, lfs_tagid(res),
lfs_min(size, lfs->attr_size)), buffer);
if (res < 0) {
if (res == LFS_ERR_NOENT) {
return LFS_ERR_NOATTR;
}
return res;
}
return lfs_tagsize(res);
}
int lfs_setattr(lfs_t *lfs, const char *path,
uint8_t type, const void *buffer, lfs_size_t size) {
if (size > lfs->attr_size) {
return LFS_ERR_NOSPC;
}
lfs_mdir_t cwd;
int32_t res = lfs_dir_lookup(lfs, &cwd, &path);
if (res < 0) {
return res;
}
return lfs_dir_commit(lfs, &cwd,
LFS_MKATTR(0x100 | type, lfs_tagid(res), buffer, size,
NULL));
}
/// Filesystem operations ///
static inline void lfs_superblockfromle32(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_size = lfs_fromle32(superblock->inline_size);
superblock->attr_size = lfs_fromle32(superblock->attr_size);
superblock->name_size = lfs_fromle32(superblock->name_size);
}
static inline void lfs_superblocktole32(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_size = lfs_tole32(superblock->inline_size);
superblock->attr_size = lfs_tole32(superblock->attr_size);
superblock->name_size = lfs_tole32(superblock->name_size);
}
static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
lfs->cfg = cfg;
// setup read cache
lfs->rcache.block = 0xffffffff;
if (lfs->cfg->read_buffer) {
lfs->rcache.buffer = lfs->cfg->read_buffer;
} else {
lfs->rcache.buffer = lfs_malloc(lfs->cfg->read_size);
if (!lfs->rcache.buffer) {
return LFS_ERR_NOMEM;
}
}
// setup program cache
lfs->pcache.block = 0xffffffff;
if (lfs->cfg->prog_buffer) {
lfs->pcache.buffer = lfs->cfg->prog_buffer;
} else {
lfs->pcache.buffer = lfs_malloc(lfs->cfg->prog_size);
if (!lfs->pcache.buffer) {
return LFS_ERR_NOMEM;
}
}
// setup lookahead, round down to nearest 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) {
return LFS_ERR_NOMEM;
}
}
// check that program and read sizes are multiples of the block size
LFS_ASSERT(lfs->cfg->prog_size % lfs->cfg->read_size == 0);
LFS_ASSERT(lfs->cfg->block_size % lfs->cfg->prog_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);
// check that the size limits are sane
LFS_ASSERT(lfs->cfg->inline_size <= LFS_INLINE_MAX);
LFS_ASSERT(lfs->cfg->inline_size <= lfs->cfg->read_size);
lfs->inline_size = lfs->cfg->inline_size;
if (!lfs->inline_size) {
lfs->inline_size = lfs_min(LFS_INLINE_MAX, lfs->cfg->read_size);
}
LFS_ASSERT(lfs->cfg->attr_size <= LFS_ATTR_MAX);
lfs->attr_size = lfs->cfg->attr_size;
if (!lfs->attr_size) {
lfs->attr_size = LFS_ATTR_MAX;
}
LFS_ASSERT(lfs->cfg->name_size <= LFS_NAME_MAX);
lfs->name_size = lfs->cfg->name_size;
if (!lfs->name_size) {
lfs->name_size = LFS_NAME_MAX;
}
// setup default state
lfs->root[0] = 0xffffffff;
lfs->root[1] = 0xffffffff;
lfs->files = NULL;
lfs->dirs = NULL;
lfs_globalones(&lfs->globals);
lfs_globalzero(&lfs->locals);
return 0;
}
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 superblock dir
lfs_mdir_t dir;
err = lfs_dir_alloc(lfs, &dir, false,
(const lfs_block_t[2]){0xffffffff, 0xffffffff});
if (err) {
return err;
}
// write root directory
lfs_mdir_t root;
err = lfs_dir_alloc(lfs, &root, false,
(const lfs_block_t[2]){0xffffffff, 0xffffffff});
if (err) {
return err;
}
err = lfs_dir_commit(lfs, &root, NULL);
if (err) {
return err;
}
lfs->root[0] = root.pair[0];
lfs->root[1] = root.pair[1];
dir.tail[0] = lfs->root[0];
dir.tail[1] = lfs->root[1];
// 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,
.inline_size = lfs->inline_size,
.attr_size = lfs->attr_size,
.name_size = lfs->name_size,
};
lfs_superblocktole32(&superblock);
lfs_pairtole32(lfs->root);
err = lfs_dir_commit(lfs, &dir,
LFS_MKATTR(LFS_TYPE_SUPERBLOCK, 0, &superblock, sizeof(superblock),
LFS_MKATTR(LFS_TYPE_DIRSTRUCT, 0, lfs->root, sizeof(lfs->root),
NULL)));
lfs_pairfromle32(lfs->root);
lfs_superblockfromle32(&superblock);
if (err) {
return err;
}
// sanity check that fetch works
err = lfs_dir_fetch(lfs, &dir, (const lfs_block_t[2]){0, 1});
if (err) {
return err;
}
return lfs_deinit(lfs);
}
int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
int err = lfs_init(lfs, cfg);
if (err) {
return err;
}
// setup free lookahead
lfs->free.off = 0;
lfs->free.size = 0;
lfs->free.i = 0;
lfs_alloc_ack(lfs);
// load superblock
lfs_mdir_t dir;
err = lfs_dir_fetch(lfs, &dir, (const lfs_block_t[2]){0, 1});
if (err) {
if (err == LFS_ERR_CORRUPT) {
LFS_ERROR("Invalid superblock at %d %d", 0, 1);
}
return err;
}
lfs_superblock_t superblock;
int32_t res = lfs_dir_get(lfs, &dir, 0x7ffff000,
LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, sizeof(superblock)),
&superblock);
if (res < 0) {
return res;
}
lfs_superblockfromle32(&superblock);
if (memcmp(superblock.magic, "littlefs", 8) != 0) {
LFS_ERROR("Invalid superblock at %d %d", 0, 1);
return LFS_ERR_CORRUPT;
}
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 %d.%d", major_version, minor_version);
return LFS_ERR_INVAL;
}
res = lfs_dir_get(lfs, &dir, 0x7ffff000,
LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 0, sizeof(lfs->root)),
&lfs->root);
if (res < 0) {
return res;
}
lfs_pairfromle32(lfs->root);
if (superblock.inline_size) {
if (superblock.inline_size > lfs->inline_size) {
LFS_ERROR("Unsupported inline size (%d > %d)",
superblock.inline_size, lfs->inline_size);
return LFS_ERR_INVAL;
}
lfs->inline_size = superblock.inline_size;
}
if (superblock.attr_size) {
if (superblock.attr_size > lfs->attr_size) {
LFS_ERROR("Unsupported attr size (%d > %d)",
superblock.attr_size, lfs->attr_size);
return LFS_ERR_INVAL;
}
lfs->attr_size = superblock.attr_size;
}
if (superblock.name_size) {
if (superblock.name_size > lfs->name_size) {
LFS_ERROR("Unsupported name size (%d > %d)",
superblock.name_size, lfs->name_size);
return LFS_ERR_INVAL;
}
lfs->name_size = superblock.name_size;
}
// scan for any global updates
err = lfs_fs_scan(lfs);
if (err) {
return err;
}
return 0;
}
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_pairisnull(lfs->root)) {
return 0;
}
// iterate over metadata pairs
lfs_mdir_t dir = {.tail = {0, 1}};
while (!lfs_pairisnull(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;
int32_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_ctzfromle32(&ctz);
if (lfs_tagtype(tag) == LFS_TYPE_CTZSTRUCT) {
int err = lfs_ctztraverse(lfs, &lfs->rcache, NULL,
ctz.head, ctz.size, cb, data);
if (err) {
return err;
}
}
}
}
// iterate over any open files
for (lfs_file_t *f = lfs->files; f; f = f->next) {
if ((f->flags & LFS_F_DIRTY) && !(f->flags & LFS_F_INLINE)) {
int err = lfs_ctztraverse(lfs, &lfs->rcache, &f->cache,
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_ctztraverse(lfs, &lfs->rcache, &f->cache,
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_pairisnull(lfs->root)) {
return LFS_ERR_NOENT;
}
// iterate over all directory directory entries
pdir->tail[0] = 0;
pdir->tail[1] = 1;
while (!lfs_pairisnull(pdir->tail)) {
if (lfs_paircmp(pdir->tail, pair) == 0) {
return 0;
}
int err = lfs_dir_fetch(lfs, pdir, pdir->tail);
if (err) {
return err;
}
}
return LFS_ERR_NOENT;
}
static int32_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t pair[2],
lfs_mdir_t *parent) {
if (lfs_pairisnull(lfs->root)) {
return LFS_ERR_NOENT;
}
// search for both orderings so we can reuse the find function
lfs_block_t child[2] = {pair[0], pair[1]};
lfs_pairtole32(child);
for (int i = 0; i < 2; i++) {
// iterate over all directory directory entries
parent->tail[0] = 0;
parent->tail[1] = 1;
while (!lfs_pairisnull(parent->tail)) {
int32_t tag = lfs_dir_find(lfs, parent, parent->tail, 0x7fc00fff,
LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 0, sizeof(child)),
child);
if (tag != LFS_ERR_NOENT) {
return tag;
}
}
lfs_pairswap(child);
}
return LFS_ERR_NOENT;
}
static int lfs_fs_relocate(lfs_t *lfs,
const lfs_block_t oldpair[2], lfs_block_t newpair[2]) {
// find parent
lfs_mdir_t parent;
int32_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_pairtole32(newpair);
int err = lfs_dir_commit(lfs, &parent,
&(lfs_mattr_t){.tag=tag, .buffer=newpair});
lfs_pairfromle32(newpair);
if (err) {
return err;
}
// update internal root
if (lfs_paircmp(oldpair, lfs->root) == 0) {
LFS_DEBUG("Relocating root %d %d", newpair[0], newpair[1]);
lfs->root[0] = newpair[0];
lfs->root[1] = newpair[1];
}
// clean up bad block, which should now be a desync
return lfs_fs_forceconsistency(lfs);
}
// 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) {
// just replace bad pair, no desync can occur
parent.tail[0] = newpair[0];
parent.tail[1] = newpair[1];
int 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_scan(lfs_t *lfs) {
if (lfs_pairisnull(lfs->root)) {
return 0;
}
// iterate over all directory directory entries
lfs_mdir_t dir = {.tail = {0, 1}};
while (!lfs_pairisnull(dir.tail)) {
int err = lfs_dir_fetch(lfs, &dir, dir.tail);
if (err) {
return err;
}
// xor together indirect deletes
lfs_globalxor(&lfs->locals, &dir.locals);
}
// update littlefs with globals
lfs_globalfromle32(&lfs->locals);
lfs_globalxor(&lfs->globals, &lfs->locals);
lfs_globalzero(&lfs->locals);
if (!lfs_pairisnull(lfs_globalmovepair(lfs))) {
LFS_DEBUG("Found move %d %d %d",
lfs_globalmovepair(lfs)[0],
lfs_globalmovepair(lfs)[1],
lfs_globalmoveid(lfs));
}
return 0;
}
static int lfs_fs_forceconsistency(lfs_t *lfs) {
if (!lfs_globalisdeorphaned(lfs)) {
LFS_DEBUG("Found orphans %d",
lfs_globalisdeorphaned(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_pairisnull(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;
int32_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 %d %d",
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];
int32_t res = lfs_dir_get(lfs, &parent, 0x7ffff000, tag, pair);
if (res < 0) {
return res;
}
lfs_pairfromle32(pair);
if (!lfs_pairsync(pair, pdir.tail)) {
// we have desynced
LFS_DEBUG("Fixing half-orphan %d %d", 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 orphan as fixed
lfs_globaldeorphaned(lfs, false);
}
if (lfs_globalmoveid(lfs) != 0x3ff) {
// Fix bad moves
LFS_DEBUG("Fixing move %d %d %d",
lfs_globalmovepair(lfs)[0],
lfs_globalmovepair(lfs)[1],
lfs_globalmoveid(lfs));
// fetch and delete the moved entry
lfs_mdir_t movedir;
int err = lfs_dir_fetch(lfs, &movedir, lfs_globalmovepair(lfs));
if (err) {
return err;
}
// rely on cancel logic inside commit
err = lfs_dir_commit(lfs, &movedir, NULL);
if (err) {
return err;
}
}
return 0;
}
lfs_ssize_t lfs_fs_getattr(lfs_t *lfs,
uint8_t type, void *buffer, lfs_size_t size) {
lfs_mdir_t superdir;
int err = lfs_dir_fetch(lfs, &superdir, (const lfs_block_t[2]){0, 1});
if (err) {
return err;
}
int32_t res = lfs_dir_get(lfs, &superdir, 0x7ffff000,
LFS_MKTAG(0x100 | type, 0,
lfs_min(size, lfs->attr_size)), buffer);
if (res < 0) {
if (res == LFS_ERR_NOENT) {
return LFS_ERR_NOATTR;
}
return res;
}
return lfs_tagsize(res);
}
int lfs_fs_setattr(lfs_t *lfs,
uint8_t type, const void *buffer, lfs_size_t size) {
if (size > lfs->attr_size) {
return LFS_ERR_NOSPC;
}
lfs_mdir_t superdir;
int err = lfs_dir_fetch(lfs, &superdir, (const lfs_block_t[2]){0, 1});
if (err) {
return err;
}
return lfs_dir_commit(lfs, &superdir,
LFS_MKATTR(0x100 | type, 0, buffer, size,
NULL));
}
static int lfs_fs_size_count(void *p, lfs_block_t 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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