diff --git a/lib/littlefs/lfs1.c b/lib/littlefs/lfs1.c new file mode 100644 index 0000000000..6a3fd67001 --- /dev/null +++ b/lib/littlefs/lfs1.c @@ -0,0 +1,2583 @@ +/* + * The little filesystem + * + * Copyright (c) 2017, Arm Limited. All rights reserved. + * SPDX-License-Identifier: BSD-3-Clause + */ +#include "lfs1.h" +#include "lfs1_util.h" + +#include + + +/// Caching block device operations /// +static int lfs1_cache_read(lfs1_t *lfs1, lfs1_cache_t *rcache, + const lfs1_cache_t *pcache, lfs1_block_t block, + lfs1_off_t off, void *buffer, lfs1_size_t size) { + uint8_t *data = buffer; + LFS1_ASSERT(block < lfs1->cfg->block_count); + + while (size > 0) { + if (pcache && block == pcache->block && off >= pcache->off && + off < pcache->off + lfs1->cfg->prog_size) { + // is already in pcache? + lfs1_size_t diff = lfs1_min(size, + lfs1->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 + lfs1->cfg->read_size) { + // is already in rcache? + lfs1_size_t diff = lfs1_min(size, + lfs1->cfg->read_size - (off-rcache->off)); + memcpy(data, &rcache->buffer[off-rcache->off], diff); + + data += diff; + off += diff; + size -= diff; + continue; + } + + if (off % lfs1->cfg->read_size == 0 && size >= lfs1->cfg->read_size) { + // bypass cache? + lfs1_size_t diff = size - (size % lfs1->cfg->read_size); + int err = lfs1->cfg->read(lfs1->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 + rcache->block = block; + rcache->off = off - (off % lfs1->cfg->read_size); + int err = lfs1->cfg->read(lfs1->cfg, rcache->block, + rcache->off, rcache->buffer, lfs1->cfg->read_size); + if (err) { + return err; + } + } + + return 0; +} + +static int lfs1_cache_cmp(lfs1_t *lfs1, lfs1_cache_t *rcache, + const lfs1_cache_t *pcache, lfs1_block_t block, + lfs1_off_t off, const void *buffer, lfs1_size_t size) { + const uint8_t *data = buffer; + + for (lfs1_off_t i = 0; i < size; i++) { + uint8_t c; + int err = lfs1_cache_read(lfs1, rcache, pcache, + block, off+i, &c, 1); + if (err) { + return err; + } + + if (c != data[i]) { + return false; + } + } + + return true; +} + +static int lfs1_cache_crc(lfs1_t *lfs1, lfs1_cache_t *rcache, + const lfs1_cache_t *pcache, lfs1_block_t block, + lfs1_off_t off, lfs1_size_t size, uint32_t *crc) { + for (lfs1_off_t i = 0; i < size; i++) { + uint8_t c; + int err = lfs1_cache_read(lfs1, rcache, pcache, + block, off+i, &c, 1); + if (err) { + return err; + } + + lfs1_crc(crc, &c, 1); + } + + return 0; +} + +static inline void lfs1_cache_drop(lfs1_t *lfs1, lfs1_cache_t *rcache) { + // do not zero, cheaper if cache is readonly or only going to be + // written with identical data (during relocates) + (void)lfs1; + rcache->block = 0xffffffff; +} + +static inline void lfs1_cache_zero(lfs1_t *lfs1, lfs1_cache_t *pcache) { + // zero to avoid information leak + memset(pcache->buffer, 0xff, lfs1->cfg->prog_size); + pcache->block = 0xffffffff; +} + +static int lfs1_cache_flush(lfs1_t *lfs1, + lfs1_cache_t *pcache, lfs1_cache_t *rcache) { + if (pcache->block != 0xffffffff) { + int err = lfs1->cfg->prog(lfs1->cfg, pcache->block, + pcache->off, pcache->buffer, lfs1->cfg->prog_size); + if (err) { + return err; + } + + if (rcache) { + int res = lfs1_cache_cmp(lfs1, rcache, NULL, pcache->block, + pcache->off, pcache->buffer, lfs1->cfg->prog_size); + if (res < 0) { + return res; + } + + if (!res) { + return LFS1_ERR_CORRUPT; + } + } + + lfs1_cache_zero(lfs1, pcache); + } + + return 0; +} + +static int lfs1_cache_prog(lfs1_t *lfs1, lfs1_cache_t *pcache, + lfs1_cache_t *rcache, lfs1_block_t block, + lfs1_off_t off, const void *buffer, lfs1_size_t size) { + const uint8_t *data = buffer; + LFS1_ASSERT(block < lfs1->cfg->block_count); + + while (size > 0) { + if (block == pcache->block && off >= pcache->off && + off < pcache->off + lfs1->cfg->prog_size) { + // is already in pcache? + lfs1_size_t diff = lfs1_min(size, + lfs1->cfg->prog_size - (off-pcache->off)); + memcpy(&pcache->buffer[off-pcache->off], data, diff); + + data += diff; + off += diff; + size -= diff; + + if (off % lfs1->cfg->prog_size == 0) { + // eagerly flush out pcache if we fill up + int err = lfs1_cache_flush(lfs1, pcache, rcache); + if (err) { + return err; + } + } + + continue; + } + + // pcache must have been flushed, either by programming and + // entire block or manually flushing the pcache + LFS1_ASSERT(pcache->block == 0xffffffff); + + if (off % lfs1->cfg->prog_size == 0 && + size >= lfs1->cfg->prog_size) { + // bypass pcache? + lfs1_size_t diff = size - (size % lfs1->cfg->prog_size); + int err = lfs1->cfg->prog(lfs1->cfg, block, off, data, diff); + if (err) { + return err; + } + + if (rcache) { + int res = lfs1_cache_cmp(lfs1, rcache, NULL, + block, off, data, diff); + if (res < 0) { + return res; + } + + if (!res) { + return LFS1_ERR_CORRUPT; + } + } + + data += diff; + off += diff; + size -= diff; + continue; + } + + // prepare pcache, first condition can no longer fail + pcache->block = block; + pcache->off = off - (off % lfs1->cfg->prog_size); + } + + return 0; +} + + +/// General lfs1 block device operations /// +static int lfs1_bd_read(lfs1_t *lfs1, lfs1_block_t block, + lfs1_off_t off, void *buffer, lfs1_size_t size) { + // if we ever do more than writes to alternating pairs, + // this may need to consider pcache + return lfs1_cache_read(lfs1, &lfs1->rcache, NULL, + block, off, buffer, size); +} + +static int lfs1_bd_prog(lfs1_t *lfs1, lfs1_block_t block, + lfs1_off_t off, const void *buffer, lfs1_size_t size) { + return lfs1_cache_prog(lfs1, &lfs1->pcache, NULL, + block, off, buffer, size); +} + +static int lfs1_bd_cmp(lfs1_t *lfs1, lfs1_block_t block, + lfs1_off_t off, const void *buffer, lfs1_size_t size) { + return lfs1_cache_cmp(lfs1, &lfs1->rcache, NULL, block, off, buffer, size); +} + +static int lfs1_bd_crc(lfs1_t *lfs1, lfs1_block_t block, + lfs1_off_t off, lfs1_size_t size, uint32_t *crc) { + return lfs1_cache_crc(lfs1, &lfs1->rcache, NULL, block, off, size, crc); +} + +static int lfs1_bd_erase(lfs1_t *lfs1, lfs1_block_t block) { + return lfs1->cfg->erase(lfs1->cfg, block); +} + +static int lfs1_bd_sync(lfs1_t *lfs1) { + lfs1_cache_drop(lfs1, &lfs1->rcache); + + int err = lfs1_cache_flush(lfs1, &lfs1->pcache, NULL); + if (err) { + return err; + } + + return lfs1->cfg->sync(lfs1->cfg); +} + + +/// Internal operations predeclared here /// +int lfs1_traverse(lfs1_t *lfs1, int (*cb)(void*, lfs1_block_t), void *data); +static int lfs1_pred(lfs1_t *lfs1, const lfs1_block_t dir[2], lfs1_dir_t *pdir); +static int lfs1_parent(lfs1_t *lfs1, const lfs1_block_t dir[2], + lfs1_dir_t *parent, lfs1_entry_t *entry); +static int lfs1_moved(lfs1_t *lfs1, const void *e); +static int lfs1_relocate(lfs1_t *lfs1, + const lfs1_block_t oldpair[2], const lfs1_block_t newpair[2]); +int lfs1_deorphan(lfs1_t *lfs1); + + +/// Block allocator /// +static int lfs1_alloc_lookahead(void *p, lfs1_block_t block) { + lfs1_t *lfs1 = p; + + lfs1_block_t off = ((block - lfs1->free.off) + + lfs1->cfg->block_count) % lfs1->cfg->block_count; + + if (off < lfs1->free.size) { + lfs1->free.buffer[off / 32] |= 1U << (off % 32); + } + + return 0; +} + +static int lfs1_alloc(lfs1_t *lfs1, lfs1_block_t *block) { + while (true) { + while (lfs1->free.i != lfs1->free.size) { + lfs1_block_t off = lfs1->free.i; + lfs1->free.i += 1; + lfs1->free.ack -= 1; + + if (!(lfs1->free.buffer[off / 32] & (1U << (off % 32)))) { + // found a free block + *block = (lfs1->free.off + off) % lfs1->cfg->block_count; + + // eagerly find next off so an alloc ack can + // discredit old lookahead blocks + while (lfs1->free.i != lfs1->free.size && + (lfs1->free.buffer[lfs1->free.i / 32] + & (1U << (lfs1->free.i % 32)))) { + lfs1->free.i += 1; + lfs1->free.ack -= 1; + } + + return 0; + } + } + + // check if we have looked at all blocks since last ack + if (lfs1->free.ack == 0) { + LFS1_WARN("No more free space %" PRIu32, + lfs1->free.i + lfs1->free.off); + return LFS1_ERR_NOSPC; + } + + lfs1->free.off = (lfs1->free.off + lfs1->free.size) + % lfs1->cfg->block_count; + lfs1->free.size = lfs1_min(lfs1->cfg->lookahead, lfs1->free.ack); + lfs1->free.i = 0; + + // find mask of free blocks from tree + memset(lfs1->free.buffer, 0, lfs1->cfg->lookahead/8); + int err = lfs1_traverse(lfs1, lfs1_alloc_lookahead, lfs1); + if (err) { + return err; + } + } +} + +static void lfs1_alloc_ack(lfs1_t *lfs1) { + lfs1->free.ack = lfs1->cfg->block_count; +} + + +/// Endian swapping functions /// +static void lfs1_dir_fromle32(struct lfs1_disk_dir *d) { + d->rev = lfs1_fromle32(d->rev); + d->size = lfs1_fromle32(d->size); + d->tail[0] = lfs1_fromle32(d->tail[0]); + d->tail[1] = lfs1_fromle32(d->tail[1]); +} + +static void lfs1_dir_tole32(struct lfs1_disk_dir *d) { + d->rev = lfs1_tole32(d->rev); + d->size = lfs1_tole32(d->size); + d->tail[0] = lfs1_tole32(d->tail[0]); + d->tail[1] = lfs1_tole32(d->tail[1]); +} + +static void lfs1_entry_fromle32(struct lfs1_disk_entry *d) { + d->u.dir[0] = lfs1_fromle32(d->u.dir[0]); + d->u.dir[1] = lfs1_fromle32(d->u.dir[1]); +} + +static void lfs1_entry_tole32(struct lfs1_disk_entry *d) { + d->u.dir[0] = lfs1_tole32(d->u.dir[0]); + d->u.dir[1] = lfs1_tole32(d->u.dir[1]); +} + +static void lfs1_superblock_fromle32(struct lfs1_disk_superblock *d) { + d->root[0] = lfs1_fromle32(d->root[0]); + d->root[1] = lfs1_fromle32(d->root[1]); + d->block_size = lfs1_fromle32(d->block_size); + d->block_count = lfs1_fromle32(d->block_count); + d->version = lfs1_fromle32(d->version); +} + +static void lfs1_superblock_tole32(struct lfs1_disk_superblock *d) { + d->root[0] = lfs1_tole32(d->root[0]); + d->root[1] = lfs1_tole32(d->root[1]); + d->block_size = lfs1_tole32(d->block_size); + d->block_count = lfs1_tole32(d->block_count); + d->version = lfs1_tole32(d->version); +} + + +/// Metadata pair and directory operations /// +static inline void lfs1_pairswap(lfs1_block_t pair[2]) { + lfs1_block_t t = pair[0]; + pair[0] = pair[1]; + pair[1] = t; +} + +static inline bool lfs1_pairisnull(const lfs1_block_t pair[2]) { + return pair[0] == 0xffffffff || pair[1] == 0xffffffff; +} + +static inline int lfs1_paircmp( + const lfs1_block_t paira[2], + const lfs1_block_t pairb[2]) { + return !(paira[0] == pairb[0] || paira[1] == pairb[1] || + paira[0] == pairb[1] || paira[1] == pairb[0]); +} + +static inline bool lfs1_pairsync( + const lfs1_block_t paira[2], + const lfs1_block_t pairb[2]) { + return (paira[0] == pairb[0] && paira[1] == pairb[1]) || + (paira[0] == pairb[1] && paira[1] == pairb[0]); +} + +static inline lfs1_size_t lfs1_entry_size(const lfs1_entry_t *entry) { + return 4 + entry->d.elen + entry->d.alen + entry->d.nlen; +} + +static int lfs1_dir_alloc(lfs1_t *lfs1, lfs1_dir_t *dir) { + // allocate pair of dir blocks + for (int i = 0; i < 2; i++) { + int err = lfs1_alloc(lfs1, &dir->pair[i]); + if (err) { + return err; + } + } + + // rather than clobbering one of the blocks we just pretend + // the revision may be valid + int err = lfs1_bd_read(lfs1, dir->pair[0], 0, &dir->d.rev, 4); + if (err && err != LFS1_ERR_CORRUPT) { + return err; + } + + if (err != LFS1_ERR_CORRUPT) { + dir->d.rev = lfs1_fromle32(dir->d.rev); + } + + // set defaults + dir->d.rev += 1; + dir->d.size = sizeof(dir->d)+4; + dir->d.tail[0] = 0xffffffff; + dir->d.tail[1] = 0xffffffff; + dir->off = sizeof(dir->d); + + // don't write out yet, let caller take care of that + return 0; +} + +static int lfs1_dir_fetch(lfs1_t *lfs1, + lfs1_dir_t *dir, const lfs1_block_t pair[2]) { + // copy out pair, otherwise may be aliasing dir + const lfs1_block_t tpair[2] = {pair[0], pair[1]}; + bool valid = false; + + // check both blocks for the most recent revision + for (int i = 0; i < 2; i++) { + struct lfs1_disk_dir test; + int err = lfs1_bd_read(lfs1, tpair[i], 0, &test, sizeof(test)); + lfs1_dir_fromle32(&test); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + continue; + } + return err; + } + + if (valid && lfs1_scmp(test.rev, dir->d.rev) < 0) { + continue; + } + + if ((0x7fffffff & test.size) < sizeof(test)+4 || + (0x7fffffff & test.size) > lfs1->cfg->block_size) { + continue; + } + + uint32_t crc = 0xffffffff; + lfs1_dir_tole32(&test); + lfs1_crc(&crc, &test, sizeof(test)); + lfs1_dir_fromle32(&test); + err = lfs1_bd_crc(lfs1, tpair[i], sizeof(test), + (0x7fffffff & test.size) - sizeof(test), &crc); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + continue; + } + return err; + } + + if (crc != 0) { + continue; + } + + valid = true; + + // setup dir in case it's valid + dir->pair[0] = tpair[(i+0) % 2]; + dir->pair[1] = tpair[(i+1) % 2]; + dir->off = sizeof(dir->d); + dir->d = test; + } + + if (!valid) { + LFS1_ERROR("Corrupted dir pair at %" PRIu32 " %" PRIu32 , + tpair[0], tpair[1]); + return LFS1_ERR_CORRUPT; + } + + return 0; +} + +struct lfs1_region { + lfs1_off_t oldoff; + lfs1_size_t oldlen; + const void *newdata; + lfs1_size_t newlen; +}; + +static int lfs1_dir_commit(lfs1_t *lfs1, lfs1_dir_t *dir, + const struct lfs1_region *regions, int count) { + // increment revision count + dir->d.rev += 1; + + // keep pairs in order such that pair[0] is most recent + lfs1_pairswap(dir->pair); + for (int i = 0; i < count; i++) { + dir->d.size += regions[i].newlen - regions[i].oldlen; + } + + const lfs1_block_t oldpair[2] = {dir->pair[0], dir->pair[1]}; + bool relocated = false; + + while (true) { + if (true) { + int err = lfs1_bd_erase(lfs1, dir->pair[0]); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + uint32_t crc = 0xffffffff; + lfs1_dir_tole32(&dir->d); + lfs1_crc(&crc, &dir->d, sizeof(dir->d)); + err = lfs1_bd_prog(lfs1, dir->pair[0], 0, &dir->d, sizeof(dir->d)); + lfs1_dir_fromle32(&dir->d); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + int i = 0; + lfs1_off_t oldoff = sizeof(dir->d); + lfs1_off_t newoff = sizeof(dir->d); + while (newoff < (0x7fffffff & dir->d.size)-4) { + if (i < count && regions[i].oldoff == oldoff) { + lfs1_crc(&crc, regions[i].newdata, regions[i].newlen); + err = lfs1_bd_prog(lfs1, dir->pair[0], + newoff, regions[i].newdata, regions[i].newlen); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + oldoff += regions[i].oldlen; + newoff += regions[i].newlen; + i += 1; + } else { + uint8_t data; + err = lfs1_bd_read(lfs1, oldpair[1], oldoff, &data, 1); + if (err) { + return err; + } + + lfs1_crc(&crc, &data, 1); + err = lfs1_bd_prog(lfs1, dir->pair[0], newoff, &data, 1); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + oldoff += 1; + newoff += 1; + } + } + + crc = lfs1_tole32(crc); + err = lfs1_bd_prog(lfs1, dir->pair[0], newoff, &crc, 4); + crc = lfs1_fromle32(crc); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + err = lfs1_bd_sync(lfs1); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + // successful commit, check checksum to make sure + uint32_t ncrc = 0xffffffff; + err = lfs1_bd_crc(lfs1, dir->pair[0], 0, + (0x7fffffff & dir->d.size)-4, &ncrc); + if (err) { + return err; + } + + if (ncrc != crc) { + goto relocate; + } + } + + break; +relocate: + //commit was corrupted + LFS1_DEBUG("Bad block at %" PRIu32, dir->pair[0]); + + // drop caches and prepare to relocate block + relocated = true; + lfs1_cache_drop(lfs1, &lfs1->pcache); + + // can't relocate superblock, filesystem is now frozen + if (lfs1_paircmp(oldpair, (const lfs1_block_t[2]){0, 1}) == 0) { + LFS1_WARN("Superblock %" PRIu32 " has become unwritable", + oldpair[0]); + return LFS1_ERR_CORRUPT; + } + + // relocate half of pair + int err = lfs1_alloc(lfs1, &dir->pair[0]); + if (err) { + return err; + } + } + + if (relocated) { + // update references if we relocated + LFS1_DEBUG("Relocating %" PRIu32 " %" PRIu32 " to %" PRIu32 " %" PRIu32, + oldpair[0], oldpair[1], dir->pair[0], dir->pair[1]); + int err = lfs1_relocate(lfs1, oldpair, dir->pair); + if (err) { + return err; + } + } + + // shift over any directories that are affected + for (lfs1_dir_t *d = lfs1->dirs; d; d = d->next) { + if (lfs1_paircmp(d->pair, dir->pair) == 0) { + d->pair[0] = dir->pair[0]; + d->pair[1] = dir->pair[1]; + } + } + + return 0; +} + +static int lfs1_dir_update(lfs1_t *lfs1, lfs1_dir_t *dir, + lfs1_entry_t *entry, const void *data) { + lfs1_entry_tole32(&entry->d); + int err = lfs1_dir_commit(lfs1, dir, (struct lfs1_region[]){ + {entry->off, sizeof(entry->d), &entry->d, sizeof(entry->d)}, + {entry->off+sizeof(entry->d), entry->d.nlen, data, entry->d.nlen} + }, data ? 2 : 1); + lfs1_entry_fromle32(&entry->d); + return err; +} + +static int lfs1_dir_append(lfs1_t *lfs1, lfs1_dir_t *dir, + lfs1_entry_t *entry, const void *data) { + // check if we fit, if top bit is set we do not and move on + while (true) { + if (dir->d.size + lfs1_entry_size(entry) <= lfs1->cfg->block_size) { + entry->off = dir->d.size - 4; + + lfs1_entry_tole32(&entry->d); + int err = lfs1_dir_commit(lfs1, dir, (struct lfs1_region[]){ + {entry->off, 0, &entry->d, sizeof(entry->d)}, + {entry->off, 0, data, entry->d.nlen} + }, 2); + lfs1_entry_fromle32(&entry->d); + return err; + } + + // we need to allocate a new dir block + if (!(0x80000000 & dir->d.size)) { + lfs1_dir_t olddir = *dir; + int err = lfs1_dir_alloc(lfs1, dir); + if (err) { + return err; + } + + dir->d.tail[0] = olddir.d.tail[0]; + dir->d.tail[1] = olddir.d.tail[1]; + entry->off = dir->d.size - 4; + lfs1_entry_tole32(&entry->d); + err = lfs1_dir_commit(lfs1, dir, (struct lfs1_region[]){ + {entry->off, 0, &entry->d, sizeof(entry->d)}, + {entry->off, 0, data, entry->d.nlen} + }, 2); + lfs1_entry_fromle32(&entry->d); + if (err) { + return err; + } + + olddir.d.size |= 0x80000000; + olddir.d.tail[0] = dir->pair[0]; + olddir.d.tail[1] = dir->pair[1]; + return lfs1_dir_commit(lfs1, &olddir, NULL, 0); + } + + int err = lfs1_dir_fetch(lfs1, dir, dir->d.tail); + if (err) { + return err; + } + } +} + +static int lfs1_dir_remove(lfs1_t *lfs1, lfs1_dir_t *dir, lfs1_entry_t *entry) { + // check if we should just drop the directory block + if ((dir->d.size & 0x7fffffff) == sizeof(dir->d)+4 + + lfs1_entry_size(entry)) { + lfs1_dir_t pdir; + int res = lfs1_pred(lfs1, dir->pair, &pdir); + if (res < 0) { + return res; + } + + if (pdir.d.size & 0x80000000) { + pdir.d.size &= dir->d.size | 0x7fffffff; + pdir.d.tail[0] = dir->d.tail[0]; + pdir.d.tail[1] = dir->d.tail[1]; + return lfs1_dir_commit(lfs1, &pdir, NULL, 0); + } + } + + // shift out the entry + int err = lfs1_dir_commit(lfs1, dir, (struct lfs1_region[]){ + {entry->off, lfs1_entry_size(entry), NULL, 0}, + }, 1); + if (err) { + return err; + } + + // shift over any files/directories that are affected + for (lfs1_file_t *f = lfs1->files; f; f = f->next) { + if (lfs1_paircmp(f->pair, dir->pair) == 0) { + if (f->poff == entry->off) { + f->pair[0] = 0xffffffff; + f->pair[1] = 0xffffffff; + } else if (f->poff > entry->off) { + f->poff -= lfs1_entry_size(entry); + } + } + } + + for (lfs1_dir_t *d = lfs1->dirs; d; d = d->next) { + if (lfs1_paircmp(d->pair, dir->pair) == 0) { + if (d->off > entry->off) { + d->off -= lfs1_entry_size(entry); + d->pos -= lfs1_entry_size(entry); + } + } + } + + return 0; +} + +static int lfs1_dir_next(lfs1_t *lfs1, lfs1_dir_t *dir, lfs1_entry_t *entry) { + while (dir->off + sizeof(entry->d) > (0x7fffffff & dir->d.size)-4) { + if (!(0x80000000 & dir->d.size)) { + entry->off = dir->off; + return LFS1_ERR_NOENT; + } + + int err = lfs1_dir_fetch(lfs1, dir, dir->d.tail); + if (err) { + return err; + } + + dir->off = sizeof(dir->d); + dir->pos += sizeof(dir->d) + 4; + } + + int err = lfs1_bd_read(lfs1, dir->pair[0], dir->off, + &entry->d, sizeof(entry->d)); + lfs1_entry_fromle32(&entry->d); + if (err) { + return err; + } + + entry->off = dir->off; + dir->off += lfs1_entry_size(entry); + dir->pos += lfs1_entry_size(entry); + return 0; +} + +static int lfs1_dir_find(lfs1_t *lfs1, lfs1_dir_t *dir, + lfs1_entry_t *entry, const char **path) { + const char *pathname = *path; + size_t pathlen; + entry->d.type = LFS1_TYPE_DIR; + entry->d.elen = sizeof(entry->d) - 4; + entry->d.alen = 0; + entry->d.nlen = 0; + entry->d.u.dir[0] = lfs1->root[0]; + entry->d.u.dir[1] = lfs1->root[1]; + + while (true) { +nextname: + // skip slashes + pathname += strspn(pathname, "/"); + pathlen = strcspn(pathname, "/"); + + // skip '.' and root '..' + if ((pathlen == 1 && memcmp(pathname, ".", 1) == 0) || + (pathlen == 2 && memcmp(pathname, "..", 2) == 0)) { + pathname += pathlen; + goto nextname; + } + + // skip if matched by '..' in name + const char *suffix = pathname + pathlen; + 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) { + pathname = suffix + sufflen; + goto nextname; + } + } else { + depth += 1; + } + + suffix += sufflen; + } + + // found path + if (pathname[0] == '\0') { + return 0; + } + + // update what we've found + *path = pathname; + + // continue on if we hit a directory + if (entry->d.type != LFS1_TYPE_DIR) { + return LFS1_ERR_NOTDIR; + } + + int err = lfs1_dir_fetch(lfs1, dir, entry->d.u.dir); + if (err) { + return err; + } + + // find entry matching name + while (true) { + err = lfs1_dir_next(lfs1, dir, entry); + if (err) { + return err; + } + + if (((0x7f & entry->d.type) != LFS1_TYPE_REG && + (0x7f & entry->d.type) != LFS1_TYPE_DIR) || + entry->d.nlen != pathlen) { + continue; + } + + int res = lfs1_bd_cmp(lfs1, dir->pair[0], + entry->off + 4+entry->d.elen+entry->d.alen, + pathname, pathlen); + if (res < 0) { + return res; + } + + // found match + if (res) { + break; + } + } + + // check that entry has not been moved + if (!lfs1->moving && entry->d.type & 0x80) { + int moved = lfs1_moved(lfs1, &entry->d.u); + if (moved < 0 || moved) { + return (moved < 0) ? moved : LFS1_ERR_NOENT; + } + + entry->d.type &= ~0x80; + } + + // to next name + pathname += pathlen; + } +} + + +/// Top level directory operations /// +int lfs1_mkdir(lfs1_t *lfs1, const char *path) { + // deorphan if we haven't yet, needed at most once after poweron + if (!lfs1->deorphaned) { + int err = lfs1_deorphan(lfs1); + if (err) { + return err; + } + } + + // fetch parent directory + lfs1_dir_t cwd; + lfs1_entry_t entry; + int err = lfs1_dir_find(lfs1, &cwd, &entry, &path); + if (err != LFS1_ERR_NOENT || strchr(path, '/') != NULL) { + return err ? err : LFS1_ERR_EXIST; + } + + // build up new directory + lfs1_alloc_ack(lfs1); + + lfs1_dir_t dir; + err = lfs1_dir_alloc(lfs1, &dir); + if (err) { + return err; + } + dir.d.tail[0] = cwd.d.tail[0]; + dir.d.tail[1] = cwd.d.tail[1]; + + err = lfs1_dir_commit(lfs1, &dir, NULL, 0); + if (err) { + return err; + } + + entry.d.type = LFS1_TYPE_DIR; + entry.d.elen = sizeof(entry.d) - 4; + entry.d.alen = 0; + entry.d.nlen = strlen(path); + entry.d.u.dir[0] = dir.pair[0]; + entry.d.u.dir[1] = dir.pair[1]; + + cwd.d.tail[0] = dir.pair[0]; + cwd.d.tail[1] = dir.pair[1]; + + err = lfs1_dir_append(lfs1, &cwd, &entry, path); + if (err) { + return err; + } + + lfs1_alloc_ack(lfs1); + return 0; +} + +int lfs1_dir_open(lfs1_t *lfs1, lfs1_dir_t *dir, const char *path) { + dir->pair[0] = lfs1->root[0]; + dir->pair[1] = lfs1->root[1]; + + lfs1_entry_t entry; + int err = lfs1_dir_find(lfs1, dir, &entry, &path); + if (err) { + return err; + } else if (entry.d.type != LFS1_TYPE_DIR) { + return LFS1_ERR_NOTDIR; + } + + err = lfs1_dir_fetch(lfs1, dir, entry.d.u.dir); + if (err) { + return err; + } + + // setup head dir + // special offset for '.' and '..' + dir->head[0] = dir->pair[0]; + dir->head[1] = dir->pair[1]; + dir->pos = sizeof(dir->d) - 2; + dir->off = sizeof(dir->d); + + // add to list of directories + dir->next = lfs1->dirs; + lfs1->dirs = dir; + + return 0; +} + +int lfs1_dir_close(lfs1_t *lfs1, lfs1_dir_t *dir) { + // remove from list of directories + for (lfs1_dir_t **p = &lfs1->dirs; *p; p = &(*p)->next) { + if (*p == dir) { + *p = dir->next; + break; + } + } + + return 0; +} + +int lfs1_dir_read(lfs1_t *lfs1, lfs1_dir_t *dir, struct lfs1_info *info) { + memset(info, 0, sizeof(*info)); + + // special offset for '.' and '..' + if (dir->pos == sizeof(dir->d) - 2) { + info->type = LFS1_TYPE_DIR; + strcpy(info->name, "."); + dir->pos += 1; + return 1; + } else if (dir->pos == sizeof(dir->d) - 1) { + info->type = LFS1_TYPE_DIR; + strcpy(info->name, ".."); + dir->pos += 1; + return 1; + } + + lfs1_entry_t entry; + while (true) { + int err = lfs1_dir_next(lfs1, dir, &entry); + if (err) { + return (err == LFS1_ERR_NOENT) ? 0 : err; + } + + if ((0x7f & entry.d.type) != LFS1_TYPE_REG && + (0x7f & entry.d.type) != LFS1_TYPE_DIR) { + continue; + } + + // check that entry has not been moved + if (entry.d.type & 0x80) { + int moved = lfs1_moved(lfs1, &entry.d.u); + if (moved < 0) { + return moved; + } + + if (moved) { + continue; + } + + entry.d.type &= ~0x80; + } + + break; + } + + info->type = entry.d.type; + if (info->type == LFS1_TYPE_REG) { + info->size = entry.d.u.file.size; + } + + int err = lfs1_bd_read(lfs1, dir->pair[0], + entry.off + 4+entry.d.elen+entry.d.alen, + info->name, entry.d.nlen); + if (err) { + return err; + } + + return 1; +} + +int lfs1_dir_seek(lfs1_t *lfs1, lfs1_dir_t *dir, lfs1_off_t off) { + // simply walk from head dir + int err = lfs1_dir_rewind(lfs1, dir); + if (err) { + return err; + } + dir->pos = off; + + while (off > (0x7fffffff & dir->d.size)) { + off -= 0x7fffffff & dir->d.size; + if (!(0x80000000 & dir->d.size)) { + return LFS1_ERR_INVAL; + } + + err = lfs1_dir_fetch(lfs1, dir, dir->d.tail); + if (err) { + return err; + } + } + + dir->off = off; + return 0; +} + +lfs1_soff_t lfs1_dir_tell(lfs1_t *lfs1, lfs1_dir_t *dir) { + (void)lfs1; + return dir->pos; +} + +int lfs1_dir_rewind(lfs1_t *lfs1, lfs1_dir_t *dir) { + // reload the head dir + int err = lfs1_dir_fetch(lfs1, dir, dir->head); + if (err) { + return err; + } + + dir->pair[0] = dir->head[0]; + dir->pair[1] = dir->head[1]; + dir->pos = sizeof(dir->d) - 2; + dir->off = sizeof(dir->d); + return 0; +} + + +/// File index list operations /// +static int lfs1_ctz_index(lfs1_t *lfs1, lfs1_off_t *off) { + lfs1_off_t size = *off; + lfs1_off_t b = lfs1->cfg->block_size - 2*4; + lfs1_off_t i = size / b; + if (i == 0) { + return 0; + } + + i = (size - 4*(lfs1_popc(i-1)+2)) / b; + *off = size - b*i - 4*lfs1_popc(i); + return i; +} + +static int lfs1_ctz_find(lfs1_t *lfs1, + lfs1_cache_t *rcache, const lfs1_cache_t *pcache, + lfs1_block_t head, lfs1_size_t size, + lfs1_size_t pos, lfs1_block_t *block, lfs1_off_t *off) { + if (size == 0) { + *block = 0xffffffff; + *off = 0; + return 0; + } + + lfs1_off_t current = lfs1_ctz_index(lfs1, &(lfs1_off_t){size-1}); + lfs1_off_t target = lfs1_ctz_index(lfs1, &pos); + + while (current > target) { + lfs1_size_t skip = lfs1_min( + lfs1_npw2(current-target+1) - 1, + lfs1_ctz(current)); + + int err = lfs1_cache_read(lfs1, rcache, pcache, head, 4*skip, &head, 4); + head = lfs1_fromle32(head); + if (err) { + return err; + } + + LFS1_ASSERT(head >= 2 && head <= lfs1->cfg->block_count); + current -= 1 << skip; + } + + *block = head; + *off = pos; + return 0; +} + +static int lfs1_ctz_extend(lfs1_t *lfs1, + lfs1_cache_t *rcache, lfs1_cache_t *pcache, + lfs1_block_t head, lfs1_size_t size, + lfs1_block_t *block, lfs1_off_t *off) { + while (true) { + // go ahead and grab a block + lfs1_block_t nblock; + int err = lfs1_alloc(lfs1, &nblock); + if (err) { + return err; + } + LFS1_ASSERT(nblock >= 2 && nblock <= lfs1->cfg->block_count); + + if (true) { + err = lfs1_bd_erase(lfs1, nblock); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + if (size == 0) { + *block = nblock; + *off = 0; + return 0; + } + + size -= 1; + lfs1_off_t index = lfs1_ctz_index(lfs1, &size); + size += 1; + + // just copy out the last block if it is incomplete + if (size != lfs1->cfg->block_size) { + for (lfs1_off_t i = 0; i < size; i++) { + uint8_t data; + err = lfs1_cache_read(lfs1, rcache, NULL, + head, i, &data, 1); + if (err) { + return err; + } + + err = lfs1_cache_prog(lfs1, pcache, rcache, + nblock, i, &data, 1); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + } + + *block = nblock; + *off = size; + return 0; + } + + // append block + index += 1; + lfs1_size_t skips = lfs1_ctz(index) + 1; + + for (lfs1_off_t i = 0; i < skips; i++) { + head = lfs1_tole32(head); + err = lfs1_cache_prog(lfs1, pcache, rcache, + nblock, 4*i, &head, 4); + head = lfs1_fromle32(head); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + if (i != skips-1) { + err = lfs1_cache_read(lfs1, rcache, NULL, + head, 4*i, &head, 4); + head = lfs1_fromle32(head); + if (err) { + return err; + } + } + + LFS1_ASSERT(head >= 2 && head <= lfs1->cfg->block_count); + } + + *block = nblock; + *off = 4*skips; + return 0; + } + +relocate: + LFS1_DEBUG("Bad block at %" PRIu32, nblock); + + // just clear cache and try a new block + lfs1_cache_drop(lfs1, &lfs1->pcache); + } +} + +static int lfs1_ctz_traverse(lfs1_t *lfs1, + lfs1_cache_t *rcache, const lfs1_cache_t *pcache, + lfs1_block_t head, lfs1_size_t size, + int (*cb)(void*, lfs1_block_t), void *data) { + if (size == 0) { + return 0; + } + + lfs1_off_t index = lfs1_ctz_index(lfs1, &(lfs1_off_t){size-1}); + + while (true) { + int err = cb(data, head); + if (err) { + return err; + } + + if (index == 0) { + return 0; + } + + lfs1_block_t heads[2]; + int count = 2 - (index & 1); + err = lfs1_cache_read(lfs1, rcache, pcache, head, 0, &heads, count*4); + heads[0] = lfs1_fromle32(heads[0]); + heads[1] = lfs1_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 lfs1_file_opencfg(lfs1_t *lfs1, lfs1_file_t *file, + const char *path, int flags, + const struct lfs1_file_config *cfg) { + // deorphan if we haven't yet, needed at most once after poweron + if ((flags & 3) != LFS1_O_RDONLY && !lfs1->deorphaned) { + int err = lfs1_deorphan(lfs1); + if (err) { + return err; + } + } + + // allocate entry for file if it doesn't exist + lfs1_dir_t cwd; + lfs1_entry_t entry; + int err = lfs1_dir_find(lfs1, &cwd, &entry, &path); + if (err && (err != LFS1_ERR_NOENT || strchr(path, '/') != NULL)) { + return err; + } + + if (err == LFS1_ERR_NOENT) { + if (!(flags & LFS1_O_CREAT)) { + return LFS1_ERR_NOENT; + } + + // create entry to remember name + entry.d.type = LFS1_TYPE_REG; + entry.d.elen = sizeof(entry.d) - 4; + entry.d.alen = 0; + entry.d.nlen = strlen(path); + entry.d.u.file.head = 0xffffffff; + entry.d.u.file.size = 0; + err = lfs1_dir_append(lfs1, &cwd, &entry, path); + if (err) { + return err; + } + } else if (entry.d.type == LFS1_TYPE_DIR) { + return LFS1_ERR_ISDIR; + } else if (flags & LFS1_O_EXCL) { + return LFS1_ERR_EXIST; + } + + // setup file struct + file->cfg = cfg; + file->pair[0] = cwd.pair[0]; + file->pair[1] = cwd.pair[1]; + file->poff = entry.off; + file->head = entry.d.u.file.head; + file->size = entry.d.u.file.size; + file->flags = flags; + file->pos = 0; + + if (flags & LFS1_O_TRUNC) { + if (file->size != 0) { + file->flags |= LFS1_F_DIRTY; + } + file->head = 0xffffffff; + file->size = 0; + } + + // allocate buffer if needed + file->cache.block = 0xffffffff; + if (file->cfg && file->cfg->buffer) { + file->cache.buffer = file->cfg->buffer; + } else if (lfs1->cfg->file_buffer) { + if (lfs1->files) { + // already in use + return LFS1_ERR_NOMEM; + } + file->cache.buffer = lfs1->cfg->file_buffer; + } else if ((file->flags & 3) == LFS1_O_RDONLY) { + file->cache.buffer = lfs1_malloc(lfs1->cfg->read_size); + if (!file->cache.buffer) { + return LFS1_ERR_NOMEM; + } + } else { + file->cache.buffer = lfs1_malloc(lfs1->cfg->prog_size); + if (!file->cache.buffer) { + return LFS1_ERR_NOMEM; + } + } + + // zero to avoid information leak + lfs1_cache_drop(lfs1, &file->cache); + if ((file->flags & 3) != LFS1_O_RDONLY) { + lfs1_cache_zero(lfs1, &file->cache); + } + + // add to list of files + file->next = lfs1->files; + lfs1->files = file; + + return 0; +} + +int lfs1_file_open(lfs1_t *lfs1, lfs1_file_t *file, + const char *path, int flags) { + return lfs1_file_opencfg(lfs1, file, path, flags, NULL); +} + +int lfs1_file_close(lfs1_t *lfs1, lfs1_file_t *file) { + int err = lfs1_file_sync(lfs1, file); + + // remove from list of files + for (lfs1_file_t **p = &lfs1->files; *p; p = &(*p)->next) { + if (*p == file) { + *p = file->next; + break; + } + } + + // clean up memory + if (!(file->cfg && file->cfg->buffer) && !lfs1->cfg->file_buffer) { + lfs1_free(file->cache.buffer); + } + + return err; +} + +static int lfs1_file_relocate(lfs1_t *lfs1, lfs1_file_t *file) { +relocate: + LFS1_DEBUG("Bad block at %" PRIu32, file->block); + + // just relocate what exists into new block + lfs1_block_t nblock; + int err = lfs1_alloc(lfs1, &nblock); + if (err) { + return err; + } + + err = lfs1_bd_erase(lfs1, nblock); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + // either read from dirty cache or disk + for (lfs1_off_t i = 0; i < file->off; i++) { + uint8_t data; + err = lfs1_cache_read(lfs1, &lfs1->rcache, &file->cache, + file->block, i, &data, 1); + if (err) { + return err; + } + + err = lfs1_cache_prog(lfs1, &lfs1->pcache, &lfs1->rcache, + nblock, i, &data, 1); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + } + + // copy over new state of file + memcpy(file->cache.buffer, lfs1->pcache.buffer, lfs1->cfg->prog_size); + file->cache.block = lfs1->pcache.block; + file->cache.off = lfs1->pcache.off; + lfs1_cache_zero(lfs1, &lfs1->pcache); + + file->block = nblock; + return 0; +} + +static int lfs1_file_flush(lfs1_t *lfs1, lfs1_file_t *file) { + if (file->flags & LFS1_F_READING) { + // just drop read cache + lfs1_cache_drop(lfs1, &file->cache); + file->flags &= ~LFS1_F_READING; + } + + if (file->flags & LFS1_F_WRITING) { + lfs1_off_t pos = file->pos; + + // copy over anything after current branch + lfs1_file_t orig = { + .head = file->head, + .size = file->size, + .flags = LFS1_O_RDONLY, + .pos = file->pos, + .cache = lfs1->rcache, + }; + lfs1_cache_drop(lfs1, &lfs1->rcache); + + while (file->pos < file->size) { + // copy over a byte at a time, leave it up to caching + // to make this efficient + uint8_t data; + lfs1_ssize_t res = lfs1_file_read(lfs1, &orig, &data, 1); + if (res < 0) { + return res; + } + + res = lfs1_file_write(lfs1, file, &data, 1); + if (res < 0) { + return res; + } + + // keep our reference to the rcache in sync + if (lfs1->rcache.block != 0xffffffff) { + lfs1_cache_drop(lfs1, &orig.cache); + lfs1_cache_drop(lfs1, &lfs1->rcache); + } + } + + // write out what we have + while (true) { + int err = lfs1_cache_flush(lfs1, &file->cache, &lfs1->rcache); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + return err; + } + + break; +relocate: + err = lfs1_file_relocate(lfs1, file); + if (err) { + return err; + } + } + + // actual file updates + file->head = file->block; + file->size = file->pos; + file->flags &= ~LFS1_F_WRITING; + file->flags |= LFS1_F_DIRTY; + + file->pos = pos; + } + + return 0; +} + +int lfs1_file_sync(lfs1_t *lfs1, lfs1_file_t *file) { + int err = lfs1_file_flush(lfs1, file); + if (err) { + return err; + } + + if ((file->flags & LFS1_F_DIRTY) && + !(file->flags & LFS1_F_ERRED) && + !lfs1_pairisnull(file->pair)) { + // update dir entry + lfs1_dir_t cwd; + err = lfs1_dir_fetch(lfs1, &cwd, file->pair); + if (err) { + return err; + } + + lfs1_entry_t entry = {.off = file->poff}; + err = lfs1_bd_read(lfs1, cwd.pair[0], entry.off, + &entry.d, sizeof(entry.d)); + lfs1_entry_fromle32(&entry.d); + if (err) { + return err; + } + + LFS1_ASSERT(entry.d.type == LFS1_TYPE_REG); + entry.d.u.file.head = file->head; + entry.d.u.file.size = file->size; + + err = lfs1_dir_update(lfs1, &cwd, &entry, NULL); + if (err) { + return err; + } + + file->flags &= ~LFS1_F_DIRTY; + } + + return 0; +} + +lfs1_ssize_t lfs1_file_read(lfs1_t *lfs1, lfs1_file_t *file, + void *buffer, lfs1_size_t size) { + uint8_t *data = buffer; + lfs1_size_t nsize = size; + + if ((file->flags & 3) == LFS1_O_WRONLY) { + return LFS1_ERR_BADF; + } + + if (file->flags & LFS1_F_WRITING) { + // flush out any writes + int err = lfs1_file_flush(lfs1, file); + if (err) { + return err; + } + } + + if (file->pos >= file->size) { + // eof if past end + return 0; + } + + size = lfs1_min(size, file->size - file->pos); + nsize = size; + + while (nsize > 0) { + // check if we need a new block + if (!(file->flags & LFS1_F_READING) || + file->off == lfs1->cfg->block_size) { + int err = lfs1_ctz_find(lfs1, &file->cache, NULL, + file->head, file->size, + file->pos, &file->block, &file->off); + if (err) { + return err; + } + + file->flags |= LFS1_F_READING; + } + + // read as much as we can in current block + lfs1_size_t diff = lfs1_min(nsize, lfs1->cfg->block_size - file->off); + int err = lfs1_cache_read(lfs1, &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; +} + +lfs1_ssize_t lfs1_file_write(lfs1_t *lfs1, lfs1_file_t *file, + const void *buffer, lfs1_size_t size) { + const uint8_t *data = buffer; + lfs1_size_t nsize = size; + + if ((file->flags & 3) == LFS1_O_RDONLY) { + return LFS1_ERR_BADF; + } + + if (file->flags & LFS1_F_READING) { + // drop any reads + int err = lfs1_file_flush(lfs1, file); + if (err) { + return err; + } + } + + if ((file->flags & LFS1_O_APPEND) && file->pos < file->size) { + file->pos = file->size; + } + + if (file->pos + size > LFS1_FILE_MAX) { + // larger than file limit? + return LFS1_ERR_FBIG; + } + + if (!(file->flags & LFS1_F_WRITING) && file->pos > file->size) { + // fill with zeros + lfs1_off_t pos = file->pos; + file->pos = file->size; + + while (file->pos < pos) { + lfs1_ssize_t res = lfs1_file_write(lfs1, file, &(uint8_t){0}, 1); + if (res < 0) { + return res; + } + } + } + + while (nsize > 0) { + // check if we need a new block + if (!(file->flags & LFS1_F_WRITING) || + file->off == lfs1->cfg->block_size) { + if (!(file->flags & LFS1_F_WRITING) && file->pos > 0) { + // find out which block we're extending from + int err = lfs1_ctz_find(lfs1, &file->cache, NULL, + file->head, file->size, + file->pos-1, &file->block, &file->off); + if (err) { + file->flags |= LFS1_F_ERRED; + return err; + } + + // mark cache as dirty since we may have read data into it + lfs1_cache_zero(lfs1, &file->cache); + } + + // extend file with new blocks + lfs1_alloc_ack(lfs1); + int err = lfs1_ctz_extend(lfs1, &lfs1->rcache, &file->cache, + file->block, file->pos, + &file->block, &file->off); + if (err) { + file->flags |= LFS1_F_ERRED; + return err; + } + + file->flags |= LFS1_F_WRITING; + } + + // program as much as we can in current block + lfs1_size_t diff = lfs1_min(nsize, lfs1->cfg->block_size - file->off); + while (true) { + int err = lfs1_cache_prog(lfs1, &file->cache, &lfs1->rcache, + file->block, file->off, data, diff); + if (err) { + if (err == LFS1_ERR_CORRUPT) { + goto relocate; + } + file->flags |= LFS1_F_ERRED; + return err; + } + + break; +relocate: + err = lfs1_file_relocate(lfs1, file); + if (err) { + file->flags |= LFS1_F_ERRED; + return err; + } + } + + file->pos += diff; + file->off += diff; + data += diff; + nsize -= diff; + + lfs1_alloc_ack(lfs1); + } + + file->flags &= ~LFS1_F_ERRED; + return size; +} + +lfs1_soff_t lfs1_file_seek(lfs1_t *lfs1, lfs1_file_t *file, + lfs1_soff_t off, int whence) { + // write out everything beforehand, may be noop if rdonly + int err = lfs1_file_flush(lfs1, file); + if (err) { + return err; + } + + // find new pos + lfs1_soff_t npos = file->pos; + if (whence == LFS1_SEEK_SET) { + npos = off; + } else if (whence == LFS1_SEEK_CUR) { + npos = file->pos + off; + } else if (whence == LFS1_SEEK_END) { + npos = file->size + off; + } + + if (npos < 0 || npos > LFS1_FILE_MAX) { + // file position out of range + return LFS1_ERR_INVAL; + } + + // update pos + file->pos = npos; + return npos; +} + +int lfs1_file_truncate(lfs1_t *lfs1, lfs1_file_t *file, lfs1_off_t size) { + if ((file->flags & 3) == LFS1_O_RDONLY) { + return LFS1_ERR_BADF; + } + + lfs1_off_t oldsize = lfs1_file_size(lfs1, file); + if (size < oldsize) { + // need to flush since directly changing metadata + int err = lfs1_file_flush(lfs1, file); + if (err) { + return err; + } + + // lookup new head in ctz skip list + err = lfs1_ctz_find(lfs1, &file->cache, NULL, + file->head, file->size, + size, &file->head, &(lfs1_off_t){0}); + if (err) { + return err; + } + + file->size = size; + file->flags |= LFS1_F_DIRTY; + } else if (size > oldsize) { + lfs1_off_t pos = file->pos; + + // flush+seek if not already at end + if (file->pos != oldsize) { + int err = lfs1_file_seek(lfs1, file, 0, LFS1_SEEK_END); + if (err < 0) { + return err; + } + } + + // fill with zeros + while (file->pos < size) { + lfs1_ssize_t res = lfs1_file_write(lfs1, file, &(uint8_t){0}, 1); + if (res < 0) { + return res; + } + } + + // restore pos + int err = lfs1_file_seek(lfs1, file, pos, LFS1_SEEK_SET); + if (err < 0) { + return err; + } + } + + return 0; +} + +lfs1_soff_t lfs1_file_tell(lfs1_t *lfs1, lfs1_file_t *file) { + (void)lfs1; + return file->pos; +} + +int lfs1_file_rewind(lfs1_t *lfs1, lfs1_file_t *file) { + lfs1_soff_t res = lfs1_file_seek(lfs1, file, 0, LFS1_SEEK_SET); + if (res < 0) { + return res; + } + + return 0; +} + +lfs1_soff_t lfs1_file_size(lfs1_t *lfs1, lfs1_file_t *file) { + (void)lfs1; + if (file->flags & LFS1_F_WRITING) { + return lfs1_max(file->pos, file->size); + } else { + return file->size; + } +} + + +/// General fs operations /// +int lfs1_stat(lfs1_t *lfs1, const char *path, struct lfs1_info *info) { + lfs1_dir_t cwd; + lfs1_entry_t entry; + int err = lfs1_dir_find(lfs1, &cwd, &entry, &path); + if (err) { + return err; + } + + memset(info, 0, sizeof(*info)); + info->type = entry.d.type; + if (info->type == LFS1_TYPE_REG) { + info->size = entry.d.u.file.size; + } + + if (lfs1_paircmp(entry.d.u.dir, lfs1->root) == 0) { + strcpy(info->name, "/"); + } else { + err = lfs1_bd_read(lfs1, cwd.pair[0], + entry.off + 4+entry.d.elen+entry.d.alen, + info->name, entry.d.nlen); + if (err) { + return err; + } + } + + return 0; +} + +int lfs1_remove(lfs1_t *lfs1, const char *path) { + // deorphan if we haven't yet, needed at most once after poweron + if (!lfs1->deorphaned) { + int err = lfs1_deorphan(lfs1); + if (err) { + return err; + } + } + + lfs1_dir_t cwd; + lfs1_entry_t entry; + int err = lfs1_dir_find(lfs1, &cwd, &entry, &path); + if (err) { + return err; + } + + lfs1_dir_t dir; + if (entry.d.type == LFS1_TYPE_DIR) { + // must be empty before removal, checking size + // without masking top bit checks for any case where + // dir is not empty + err = lfs1_dir_fetch(lfs1, &dir, entry.d.u.dir); + if (err) { + return err; + } else if (dir.d.size != sizeof(dir.d)+4) { + return LFS1_ERR_NOTEMPTY; + } + } + + // remove the entry + err = lfs1_dir_remove(lfs1, &cwd, &entry); + if (err) { + return err; + } + + // if we were a directory, find pred, replace tail + if (entry.d.type == LFS1_TYPE_DIR) { + int res = lfs1_pred(lfs1, dir.pair, &cwd); + if (res < 0) { + return res; + } + + LFS1_ASSERT(res); // must have pred + cwd.d.tail[0] = dir.d.tail[0]; + cwd.d.tail[1] = dir.d.tail[1]; + + err = lfs1_dir_commit(lfs1, &cwd, NULL, 0); + if (err) { + return err; + } + } + + return 0; +} + +int lfs1_rename(lfs1_t *lfs1, const char *oldpath, const char *newpath) { + // deorphan if we haven't yet, needed at most once after poweron + if (!lfs1->deorphaned) { + int err = lfs1_deorphan(lfs1); + if (err) { + return err; + } + } + + // find old entry + lfs1_dir_t oldcwd; + lfs1_entry_t oldentry; + int err = lfs1_dir_find(lfs1, &oldcwd, &oldentry, &(const char *){oldpath}); + if (err) { + return err; + } + + // mark as moving + oldentry.d.type |= 0x80; + err = lfs1_dir_update(lfs1, &oldcwd, &oldentry, NULL); + if (err) { + return err; + } + + // allocate new entry + lfs1_dir_t newcwd; + lfs1_entry_t preventry; + err = lfs1_dir_find(lfs1, &newcwd, &preventry, &newpath); + if (err && (err != LFS1_ERR_NOENT || strchr(newpath, '/') != NULL)) { + return err; + } + + // must have same type + bool prevexists = (err != LFS1_ERR_NOENT); + if (prevexists && preventry.d.type != (0x7f & oldentry.d.type)) { + return LFS1_ERR_ISDIR; + } + + lfs1_dir_t dir; + if (prevexists && preventry.d.type == LFS1_TYPE_DIR) { + // must be empty before removal, checking size + // without masking top bit checks for any case where + // dir is not empty + err = lfs1_dir_fetch(lfs1, &dir, preventry.d.u.dir); + if (err) { + return err; + } else if (dir.d.size != sizeof(dir.d)+4) { + return LFS1_ERR_NOTEMPTY; + } + } + + // move to new location + lfs1_entry_t newentry = preventry; + newentry.d = oldentry.d; + newentry.d.type &= ~0x80; + newentry.d.nlen = strlen(newpath); + + if (prevexists) { + err = lfs1_dir_update(lfs1, &newcwd, &newentry, newpath); + if (err) { + return err; + } + } else { + err = lfs1_dir_append(lfs1, &newcwd, &newentry, newpath); + if (err) { + return err; + } + } + + // fetch old pair again in case dir block changed + lfs1->moving = true; + err = lfs1_dir_find(lfs1, &oldcwd, &oldentry, &oldpath); + if (err) { + return err; + } + lfs1->moving = false; + + // remove old entry + err = lfs1_dir_remove(lfs1, &oldcwd, &oldentry); + if (err) { + return err; + } + + // if we were a directory, find pred, replace tail + if (prevexists && preventry.d.type == LFS1_TYPE_DIR) { + int res = lfs1_pred(lfs1, dir.pair, &newcwd); + if (res < 0) { + return res; + } + + LFS1_ASSERT(res); // must have pred + newcwd.d.tail[0] = dir.d.tail[0]; + newcwd.d.tail[1] = dir.d.tail[1]; + + err = lfs1_dir_commit(lfs1, &newcwd, NULL, 0); + if (err) { + return err; + } + } + + return 0; +} + + +/// Filesystem operations /// +static void lfs1_deinit(lfs1_t *lfs1) { + // free allocated memory + if (!lfs1->cfg->read_buffer) { + lfs1_free(lfs1->rcache.buffer); + } + + if (!lfs1->cfg->prog_buffer) { + lfs1_free(lfs1->pcache.buffer); + } + + if (!lfs1->cfg->lookahead_buffer) { + lfs1_free(lfs1->free.buffer); + } +} + +static int lfs1_init(lfs1_t *lfs1, const struct lfs1_config *cfg) { + lfs1->cfg = cfg; + + // setup read cache + if (lfs1->cfg->read_buffer) { + lfs1->rcache.buffer = lfs1->cfg->read_buffer; + } else { + lfs1->rcache.buffer = lfs1_malloc(lfs1->cfg->read_size); + if (!lfs1->rcache.buffer) { + goto cleanup; + } + } + + // setup program cache + if (lfs1->cfg->prog_buffer) { + lfs1->pcache.buffer = lfs1->cfg->prog_buffer; + } else { + lfs1->pcache.buffer = lfs1_malloc(lfs1->cfg->prog_size); + if (!lfs1->pcache.buffer) { + goto cleanup; + } + } + + // zero to avoid information leaks + lfs1_cache_zero(lfs1, &lfs1->pcache); + lfs1_cache_drop(lfs1, &lfs1->rcache); + + // setup lookahead, round down to nearest 32-bits + LFS1_ASSERT(lfs1->cfg->lookahead % 32 == 0); + LFS1_ASSERT(lfs1->cfg->lookahead > 0); + if (lfs1->cfg->lookahead_buffer) { + lfs1->free.buffer = lfs1->cfg->lookahead_buffer; + } else { + lfs1->free.buffer = lfs1_malloc(lfs1->cfg->lookahead/8); + if (!lfs1->free.buffer) { + goto cleanup; + } + } + + // check that program and read sizes are multiples of the block size + LFS1_ASSERT(lfs1->cfg->prog_size % lfs1->cfg->read_size == 0); + LFS1_ASSERT(lfs1->cfg->block_size % lfs1->cfg->prog_size == 0); + + // check that the block size is large enough to fit ctz pointers + LFS1_ASSERT(4*lfs1_npw2(0xffffffff / (lfs1->cfg->block_size-2*4)) + <= lfs1->cfg->block_size); + + // setup default state + lfs1->root[0] = 0xffffffff; + lfs1->root[1] = 0xffffffff; + lfs1->files = NULL; + lfs1->dirs = NULL; + lfs1->deorphaned = false; + lfs1->moving = false; + + return 0; + +cleanup: + lfs1_deinit(lfs1); + return LFS1_ERR_NOMEM; +} + +int lfs1_format(lfs1_t *lfs1, const struct lfs1_config *cfg) { + int err = 0; + if (true) { + err = lfs1_init(lfs1, cfg); + if (err) { + return err; + } + + // create free lookahead + memset(lfs1->free.buffer, 0, lfs1->cfg->lookahead/8); + lfs1->free.off = 0; + lfs1->free.size = lfs1_min(lfs1->cfg->lookahead, lfs1->cfg->block_count); + lfs1->free.i = 0; + lfs1_alloc_ack(lfs1); + + // create superblock dir + lfs1_dir_t superdir; + err = lfs1_dir_alloc(lfs1, &superdir); + if (err) { + goto cleanup; + } + + // write root directory + lfs1_dir_t root; + err = lfs1_dir_alloc(lfs1, &root); + if (err) { + goto cleanup; + } + + err = lfs1_dir_commit(lfs1, &root, NULL, 0); + if (err) { + goto cleanup; + } + + lfs1->root[0] = root.pair[0]; + lfs1->root[1] = root.pair[1]; + + // write superblocks + lfs1_superblock_t superblock = { + .off = sizeof(superdir.d), + .d.type = LFS1_TYPE_SUPERBLOCK, + .d.elen = sizeof(superblock.d) - sizeof(superblock.d.magic) - 4, + .d.nlen = sizeof(superblock.d.magic), + .d.version = LFS1_DISK_VERSION, + .d.magic = {"littlefs"}, + .d.block_size = lfs1->cfg->block_size, + .d.block_count = lfs1->cfg->block_count, + .d.root = {lfs1->root[0], lfs1->root[1]}, + }; + superdir.d.tail[0] = root.pair[0]; + superdir.d.tail[1] = root.pair[1]; + superdir.d.size = sizeof(superdir.d) + sizeof(superblock.d) + 4; + + // write both pairs to be safe + lfs1_superblock_tole32(&superblock.d); + bool valid = false; + for (int i = 0; i < 2; i++) { + err = lfs1_dir_commit(lfs1, &superdir, (struct lfs1_region[]){ + {sizeof(superdir.d), sizeof(superblock.d), + &superblock.d, sizeof(superblock.d)} + }, 1); + if (err && err != LFS1_ERR_CORRUPT) { + goto cleanup; + } + + valid = valid || !err; + } + + if (!valid) { + err = LFS1_ERR_CORRUPT; + goto cleanup; + } + + // sanity check that fetch works + err = lfs1_dir_fetch(lfs1, &superdir, (const lfs1_block_t[2]){0, 1}); + if (err) { + goto cleanup; + } + + lfs1_alloc_ack(lfs1); + } + +cleanup: + lfs1_deinit(lfs1); + return err; +} + +int lfs1_mount(lfs1_t *lfs1, const struct lfs1_config *cfg) { + int err = 0; + if (true) { + err = lfs1_init(lfs1, cfg); + if (err) { + return err; + } + + // setup free lookahead + lfs1->free.off = 0; + lfs1->free.size = 0; + lfs1->free.i = 0; + lfs1_alloc_ack(lfs1); + + // load superblock + lfs1_dir_t dir; + lfs1_superblock_t superblock; + err = lfs1_dir_fetch(lfs1, &dir, (const lfs1_block_t[2]){0, 1}); + if (err && err != LFS1_ERR_CORRUPT) { + goto cleanup; + } + + if (!err) { + err = lfs1_bd_read(lfs1, dir.pair[0], sizeof(dir.d), + &superblock.d, sizeof(superblock.d)); + lfs1_superblock_fromle32(&superblock.d); + if (err) { + goto cleanup; + } + + lfs1->root[0] = superblock.d.root[0]; + lfs1->root[1] = superblock.d.root[1]; + } + + if (err || memcmp(superblock.d.magic, "littlefs", 8) != 0) { + LFS1_ERROR("Invalid superblock at %d %d", 0, 1); + err = LFS1_ERR_CORRUPT; + goto cleanup; + } + + uint16_t major_version = (0xffff & (superblock.d.version >> 16)); + uint16_t minor_version = (0xffff & (superblock.d.version >> 0)); + if ((major_version != LFS1_DISK_VERSION_MAJOR || + minor_version > LFS1_DISK_VERSION_MINOR)) { + LFS1_ERROR("Invalid version %d.%d", major_version, minor_version); + err = LFS1_ERR_INVAL; + goto cleanup; + } + + return 0; + } + +cleanup: + + lfs1_deinit(lfs1); + return err; +} + +int lfs1_unmount(lfs1_t *lfs1) { + lfs1_deinit(lfs1); + return 0; +} + + +/// Littlefs specific operations /// +int lfs1_traverse(lfs1_t *lfs1, int (*cb)(void*, lfs1_block_t), void *data) { + if (lfs1_pairisnull(lfs1->root)) { + return 0; + } + + // iterate over metadata pairs + lfs1_dir_t dir; + lfs1_entry_t entry; + lfs1_block_t cwd[2] = {0, 1}; + + while (true) { + for (int i = 0; i < 2; i++) { + int err = cb(data, cwd[i]); + if (err) { + return err; + } + } + + int err = lfs1_dir_fetch(lfs1, &dir, cwd); + if (err) { + return err; + } + + // iterate over contents + while (dir.off + sizeof(entry.d) <= (0x7fffffff & dir.d.size)-4) { + err = lfs1_bd_read(lfs1, dir.pair[0], dir.off, + &entry.d, sizeof(entry.d)); + lfs1_entry_fromle32(&entry.d); + if (err) { + return err; + } + + dir.off += lfs1_entry_size(&entry); + if ((0x70 & entry.d.type) == (0x70 & LFS1_TYPE_REG)) { + err = lfs1_ctz_traverse(lfs1, &lfs1->rcache, NULL, + entry.d.u.file.head, entry.d.u.file.size, cb, data); + if (err) { + return err; + } + } + } + + cwd[0] = dir.d.tail[0]; + cwd[1] = dir.d.tail[1]; + + if (lfs1_pairisnull(cwd)) { + break; + } + } + + // iterate over any open files + for (lfs1_file_t *f = lfs1->files; f; f = f->next) { + if (f->flags & LFS1_F_DIRTY) { + int err = lfs1_ctz_traverse(lfs1, &lfs1->rcache, &f->cache, + f->head, f->size, cb, data); + if (err) { + return err; + } + } + + if (f->flags & LFS1_F_WRITING) { + int err = lfs1_ctz_traverse(lfs1, &lfs1->rcache, &f->cache, + f->block, f->pos, cb, data); + if (err) { + return err; + } + } + } + + return 0; +} + +static int lfs1_pred(lfs1_t *lfs1, const lfs1_block_t dir[2], lfs1_dir_t *pdir) { + if (lfs1_pairisnull(lfs1->root)) { + return 0; + } + + // iterate over all directory directory entries + int err = lfs1_dir_fetch(lfs1, pdir, (const lfs1_block_t[2]){0, 1}); + if (err) { + return err; + } + + while (!lfs1_pairisnull(pdir->d.tail)) { + if (lfs1_paircmp(pdir->d.tail, dir) == 0) { + return true; + } + + err = lfs1_dir_fetch(lfs1, pdir, pdir->d.tail); + if (err) { + return err; + } + } + + return false; +} + +static int lfs1_parent(lfs1_t *lfs1, const lfs1_block_t dir[2], + lfs1_dir_t *parent, lfs1_entry_t *entry) { + if (lfs1_pairisnull(lfs1->root)) { + return 0; + } + + parent->d.tail[0] = 0; + parent->d.tail[1] = 1; + + // iterate over all directory directory entries + while (!lfs1_pairisnull(parent->d.tail)) { + int err = lfs1_dir_fetch(lfs1, parent, parent->d.tail); + if (err) { + return err; + } + + while (true) { + err = lfs1_dir_next(lfs1, parent, entry); + if (err && err != LFS1_ERR_NOENT) { + return err; + } + + if (err == LFS1_ERR_NOENT) { + break; + } + + if (((0x70 & entry->d.type) == (0x70 & LFS1_TYPE_DIR)) && + lfs1_paircmp(entry->d.u.dir, dir) == 0) { + return true; + } + } + } + + return false; +} + +static int lfs1_moved(lfs1_t *lfs1, const void *e) { + if (lfs1_pairisnull(lfs1->root)) { + return 0; + } + + // skip superblock + lfs1_dir_t cwd; + int err = lfs1_dir_fetch(lfs1, &cwd, (const lfs1_block_t[2]){0, 1}); + if (err) { + return err; + } + + // iterate over all directory directory entries + lfs1_entry_t entry; + while (!lfs1_pairisnull(cwd.d.tail)) { + err = lfs1_dir_fetch(lfs1, &cwd, cwd.d.tail); + if (err) { + return err; + } + + while (true) { + err = lfs1_dir_next(lfs1, &cwd, &entry); + if (err && err != LFS1_ERR_NOENT) { + return err; + } + + if (err == LFS1_ERR_NOENT) { + break; + } + + if (!(0x80 & entry.d.type) && + memcmp(&entry.d.u, e, sizeof(entry.d.u)) == 0) { + return true; + } + } + } + + return false; +} + +static int lfs1_relocate(lfs1_t *lfs1, + const lfs1_block_t oldpair[2], const lfs1_block_t newpair[2]) { + // find parent + lfs1_dir_t parent; + lfs1_entry_t entry; + int res = lfs1_parent(lfs1, oldpair, &parent, &entry); + if (res < 0) { + return res; + } + + if (res) { + // update disk, this creates a desync + entry.d.u.dir[0] = newpair[0]; + entry.d.u.dir[1] = newpair[1]; + + int err = lfs1_dir_update(lfs1, &parent, &entry, NULL); + if (err) { + return err; + } + + // update internal root + if (lfs1_paircmp(oldpair, lfs1->root) == 0) { + LFS1_DEBUG("Relocating root %" PRIu32 " %" PRIu32, + newpair[0], newpair[1]); + lfs1->root[0] = newpair[0]; + lfs1->root[1] = newpair[1]; + } + + // clean up bad block, which should now be a desync + return lfs1_deorphan(lfs1); + } + + // find pred + res = lfs1_pred(lfs1, oldpair, &parent); + if (res < 0) { + return res; + } + + if (res) { + // just replace bad pair, no desync can occur + parent.d.tail[0] = newpair[0]; + parent.d.tail[1] = newpair[1]; + + return lfs1_dir_commit(lfs1, &parent, NULL, 0); + } + + // couldn't find dir, must be new + return 0; +} + +int lfs1_deorphan(lfs1_t *lfs1) { + lfs1->deorphaned = true; + + if (lfs1_pairisnull(lfs1->root)) { + return 0; + } + + lfs1_dir_t pdir = {.d.size = 0x80000000}; + lfs1_dir_t cwd = {.d.tail[0] = 0, .d.tail[1] = 1}; + + // iterate over all directory directory entries + for (lfs1_size_t i = 0; i < lfs1->cfg->block_count; i++) { + if (lfs1_pairisnull(cwd.d.tail)) { + return 0; + } + + int err = lfs1_dir_fetch(lfs1, &cwd, cwd.d.tail); + if (err) { + return err; + } + + // check head blocks for orphans + if (!(0x80000000 & pdir.d.size)) { + // check if we have a parent + lfs1_dir_t parent; + lfs1_entry_t entry; + int res = lfs1_parent(lfs1, pdir.d.tail, &parent, &entry); + if (res < 0) { + return res; + } + + if (!res) { + // we are an orphan + LFS1_DEBUG("Found orphan %" PRIu32 " %" PRIu32, + pdir.d.tail[0], pdir.d.tail[1]); + + pdir.d.tail[0] = cwd.d.tail[0]; + pdir.d.tail[1] = cwd.d.tail[1]; + + err = lfs1_dir_commit(lfs1, &pdir, NULL, 0); + if (err) { + return err; + } + + return 0; + } + + if (!lfs1_pairsync(entry.d.u.dir, pdir.d.tail)) { + // we have desynced + LFS1_DEBUG("Found desync %" PRIu32 " %" PRIu32, + entry.d.u.dir[0], entry.d.u.dir[1]); + + pdir.d.tail[0] = entry.d.u.dir[0]; + pdir.d.tail[1] = entry.d.u.dir[1]; + + err = lfs1_dir_commit(lfs1, &pdir, NULL, 0); + if (err) { + return err; + } + + return 0; + } + } + + // check entries for moves + lfs1_entry_t entry; + while (true) { + err = lfs1_dir_next(lfs1, &cwd, &entry); + if (err && err != LFS1_ERR_NOENT) { + return err; + } + + if (err == LFS1_ERR_NOENT) { + break; + } + + // found moved entry + if (entry.d.type & 0x80) { + int moved = lfs1_moved(lfs1, &entry.d.u); + if (moved < 0) { + return moved; + } + + if (moved) { + LFS1_DEBUG("Found move %" PRIu32 " %" PRIu32, + entry.d.u.dir[0], entry.d.u.dir[1]); + err = lfs1_dir_remove(lfs1, &cwd, &entry); + if (err) { + return err; + } + } else { + LFS1_DEBUG("Found partial move %" PRIu32 " %" PRIu32, + entry.d.u.dir[0], entry.d.u.dir[1]); + entry.d.type &= ~0x80; + err = lfs1_dir_update(lfs1, &cwd, &entry, NULL); + if (err) { + return err; + } + } + } + } + + memcpy(&pdir, &cwd, sizeof(pdir)); + } + + // If we reached here, we have more directory pairs than blocks in the + // filesystem... So something must be horribly wrong + return LFS1_ERR_CORRUPT; +} diff --git a/lib/littlefs/lfs1.h b/lib/littlefs/lfs1.h new file mode 100644 index 0000000000..355c145d08 --- /dev/null +++ b/lib/littlefs/lfs1.h @@ -0,0 +1,501 @@ +/* + * The little filesystem + * + * Copyright (c) 2017, Arm Limited. All rights reserved. + * SPDX-License-Identifier: BSD-3-Clause + */ +#ifndef LFS1_H +#define LFS1_H + +#include +#include + +#ifdef __cplusplus +extern "C" +{ +#endif + + +/// Version info /// + +// Software library version +// Major (top-nibble), incremented on backwards incompatible changes +// Minor (bottom-nibble), incremented on feature additions +#define LFS1_VERSION 0x00010007 +#define LFS1_VERSION_MAJOR (0xffff & (LFS1_VERSION >> 16)) +#define LFS1_VERSION_MINOR (0xffff & (LFS1_VERSION >> 0)) + +// Version of On-disk data structures +// Major (top-nibble), incremented on backwards incompatible changes +// Minor (bottom-nibble), incremented on feature additions +#define LFS1_DISK_VERSION 0x00010001 +#define LFS1_DISK_VERSION_MAJOR (0xffff & (LFS1_DISK_VERSION >> 16)) +#define LFS1_DISK_VERSION_MINOR (0xffff & (LFS1_DISK_VERSION >> 0)) + + +/// Definitions /// + +// Type definitions +typedef uint32_t lfs1_size_t; +typedef uint32_t lfs1_off_t; + +typedef int32_t lfs1_ssize_t; +typedef int32_t lfs1_soff_t; + +typedef uint32_t lfs1_block_t; + +// Max name size in bytes +#ifndef LFS1_NAME_MAX +#define LFS1_NAME_MAX 255 +#endif + +// Max file size in bytes +#ifndef LFS1_FILE_MAX +#define LFS1_FILE_MAX 2147483647 +#endif + +// Possible error codes, these are negative to allow +// valid positive return values +enum lfs1_error { + LFS1_ERR_OK = 0, // No error + LFS1_ERR_IO = -5, // Error during device operation + LFS1_ERR_CORRUPT = -52, // Corrupted + LFS1_ERR_NOENT = -2, // No directory entry + LFS1_ERR_EXIST = -17, // Entry already exists + LFS1_ERR_NOTDIR = -20, // Entry is not a dir + LFS1_ERR_ISDIR = -21, // Entry is a dir + LFS1_ERR_NOTEMPTY = -39, // Dir is not empty + LFS1_ERR_BADF = -9, // Bad file number + LFS1_ERR_FBIG = -27, // File too large + LFS1_ERR_INVAL = -22, // Invalid parameter + LFS1_ERR_NOSPC = -28, // No space left on device + LFS1_ERR_NOMEM = -12, // No more memory available +}; + +// File types +enum lfs1_type { + LFS1_TYPE_REG = 0x11, + LFS1_TYPE_DIR = 0x22, + LFS1_TYPE_SUPERBLOCK = 0x2e, +}; + +// File open flags +enum lfs1_open_flags { + // open flags + LFS1_O_RDONLY = 1, // Open a file as read only + LFS1_O_WRONLY = 2, // Open a file as write only + LFS1_O_RDWR = 3, // Open a file as read and write + LFS1_O_CREAT = 0x0100, // Create a file if it does not exist + LFS1_O_EXCL = 0x0200, // Fail if a file already exists + LFS1_O_TRUNC = 0x0400, // Truncate the existing file to zero size + LFS1_O_APPEND = 0x0800, // Move to end of file on every write + + // internally used flags + LFS1_F_DIRTY = 0x10000, // File does not match storage + LFS1_F_WRITING = 0x20000, // File has been written since last flush + LFS1_F_READING = 0x40000, // File has been read since last flush + LFS1_F_ERRED = 0x80000, // An error occured during write +}; + +// File seek flags +enum lfs1_whence_flags { + LFS1_SEEK_SET = 0, // Seek relative to an absolute position + LFS1_SEEK_CUR = 1, // Seek relative to the current file position + LFS1_SEEK_END = 2, // Seek relative to the end of the file +}; + + +// Configuration provided during initialization of the littlefs +struct lfs1_config { + // Opaque user provided context that can be used to pass + // information to the block device operations + void *context; + + // Read a region in a block. Negative error codes are propogated + // to the user. + int (*read)(const struct lfs1_config *c, lfs1_block_t block, + lfs1_off_t off, void *buffer, lfs1_size_t size); + + // Program a region in a block. The block must have previously + // been erased. Negative error codes are propogated to the user. + // May return LFS1_ERR_CORRUPT if the block should be considered bad. + int (*prog)(const struct lfs1_config *c, lfs1_block_t block, + lfs1_off_t off, const void *buffer, lfs1_size_t size); + + // Erase a block. A block must be erased before being programmed. + // The state of an erased block is undefined. Negative error codes + // are propogated to the user. + // May return LFS1_ERR_CORRUPT if the block should be considered bad. + int (*erase)(const struct lfs1_config *c, lfs1_block_t block); + + // Sync the state of the underlying block device. Negative error codes + // are propogated to the user. + int (*sync)(const struct lfs1_config *c); + + // Minimum size of a block read. This determines the size of read buffers. + // This may be larger than the physical read size to improve performance + // by caching more of the block device. + lfs1_size_t read_size; + + // Minimum size of a block program. This determines the size of program + // buffers. This may be larger than the physical program size to improve + // performance by caching more of the block device. + // Must be a multiple of the read size. + lfs1_size_t prog_size; + + // Size of an erasable block. This does not impact ram consumption and + // may be larger than the physical erase size. However, this should be + // kept small as each file currently takes up an entire block. + // Must be a multiple of the program size. + lfs1_size_t block_size; + + // Number of erasable blocks on the device. + lfs1_size_t block_count; + + // Number of blocks to lookahead during block allocation. A larger + // lookahead reduces the number of passes required to allocate a block. + // The lookahead buffer requires only 1 bit per block so it can be quite + // large with little ram impact. Should be a multiple of 32. + lfs1_size_t lookahead; + + // Optional, statically allocated read buffer. Must be read sized. + void *read_buffer; + + // Optional, statically allocated program buffer. Must be program sized. + void *prog_buffer; + + // Optional, statically allocated lookahead buffer. Must be 1 bit per + // lookahead block. + void *lookahead_buffer; + + // Optional, statically allocated buffer for files. Must be program sized. + // If enabled, only one file may be opened at a time. + void *file_buffer; +}; + +// Optional configuration provided during lfs1_file_opencfg +struct lfs1_file_config { + // Optional, statically allocated buffer for files. Must be program sized. + // If NULL, malloc will be used by default. + void *buffer; +}; + +// File info structure +struct lfs1_info { + // Type of the file, either LFS1_TYPE_REG or LFS1_TYPE_DIR + uint8_t type; + + // Size of the file, only valid for REG files + lfs1_size_t size; + + // Name of the file stored as a null-terminated string + char name[LFS1_NAME_MAX+1]; +}; + + +/// littlefs data structures /// +typedef struct lfs1_entry { + lfs1_off_t off; + + struct lfs1_disk_entry { + uint8_t type; + uint8_t elen; + uint8_t alen; + uint8_t nlen; + union { + struct { + lfs1_block_t head; + lfs1_size_t size; + } file; + lfs1_block_t dir[2]; + } u; + } d; +} lfs1_entry_t; + +typedef struct lfs1_cache { + lfs1_block_t block; + lfs1_off_t off; + uint8_t *buffer; +} lfs1_cache_t; + +typedef struct lfs1_file { + struct lfs1_file *next; + lfs1_block_t pair[2]; + lfs1_off_t poff; + + lfs1_block_t head; + lfs1_size_t size; + + const struct lfs1_file_config *cfg; + uint32_t flags; + lfs1_off_t pos; + lfs1_block_t block; + lfs1_off_t off; + lfs1_cache_t cache; +} lfs1_file_t; + +typedef struct lfs1_dir { + struct lfs1_dir *next; + lfs1_block_t pair[2]; + lfs1_off_t off; + + lfs1_block_t head[2]; + lfs1_off_t pos; + + struct lfs1_disk_dir { + uint32_t rev; + lfs1_size_t size; + lfs1_block_t tail[2]; + } d; +} lfs1_dir_t; + +typedef struct lfs1_superblock { + lfs1_off_t off; + + struct lfs1_disk_superblock { + uint8_t type; + uint8_t elen; + uint8_t alen; + uint8_t nlen; + lfs1_block_t root[2]; + uint32_t block_size; + uint32_t block_count; + uint32_t version; + char magic[8]; + } d; +} lfs1_superblock_t; + +typedef struct lfs1_free { + lfs1_block_t off; + lfs1_block_t size; + lfs1_block_t i; + lfs1_block_t ack; + uint32_t *buffer; +} lfs1_free_t; + +// The littlefs type +typedef struct lfs1 { + const struct lfs1_config *cfg; + + lfs1_block_t root[2]; + lfs1_file_t *files; + lfs1_dir_t *dirs; + + lfs1_cache_t rcache; + lfs1_cache_t pcache; + + lfs1_free_t free; + bool deorphaned; + bool moving; +} lfs1_t; + + +/// Filesystem functions /// + +// Format a block device with the littlefs +// +// Requires a littlefs object and config struct. This clobbers the littlefs +// object, and does not leave the filesystem mounted. The config struct must +// be zeroed for defaults and backwards compatibility. +// +// Returns a negative error code on failure. +int lfs1_format(lfs1_t *lfs1, const struct lfs1_config *config); + +// Mounts a littlefs +// +// Requires a littlefs object and config struct. Multiple filesystems +// may be mounted simultaneously with multiple littlefs objects. Both +// lfs1 and config must be allocated while mounted. The config struct must +// be zeroed for defaults and backwards compatibility. +// +// Returns a negative error code on failure. +int lfs1_mount(lfs1_t *lfs1, const struct lfs1_config *config); + +// Unmounts a littlefs +// +// Does nothing besides releasing any allocated resources. +// Returns a negative error code on failure. +int lfs1_unmount(lfs1_t *lfs1); + +/// General operations /// + +// Removes a file or directory +// +// If removing a directory, the directory must be empty. +// Returns a negative error code on failure. +int lfs1_remove(lfs1_t *lfs1, const char *path); + +// Rename or move a file or directory +// +// If the destination exists, it must match the source in type. +// If the destination is a directory, the directory must be empty. +// +// Returns a negative error code on failure. +int lfs1_rename(lfs1_t *lfs1, const char *oldpath, const char *newpath); + +// Find info about a file or directory +// +// Fills out the info structure, based on the specified file or directory. +// Returns a negative error code on failure. +int lfs1_stat(lfs1_t *lfs1, const char *path, struct lfs1_info *info); + + +/// File operations /// + +// Open a file +// +// The mode that the file is opened in is determined by the flags, which +// are values from the enum lfs1_open_flags that are bitwise-ored together. +// +// Returns a negative error code on failure. +int lfs1_file_open(lfs1_t *lfs1, lfs1_file_t *file, + const char *path, int flags); + +// Open a file with extra configuration +// +// The mode that the file is opened in is determined by the flags, which +// are values from the enum lfs1_open_flags that are bitwise-ored together. +// +// The config struct provides additional config options per file as described +// above. The config struct must be allocated while the file is open, and the +// config struct must be zeroed for defaults and backwards compatibility. +// +// Returns a negative error code on failure. +int lfs1_file_opencfg(lfs1_t *lfs1, lfs1_file_t *file, + const char *path, int flags, + const struct lfs1_file_config *config); + +// Close a file +// +// Any pending writes are written out to storage as though +// sync had been called and releases any allocated resources. +// +// Returns a negative error code on failure. +int lfs1_file_close(lfs1_t *lfs1, lfs1_file_t *file); + +// Synchronize a file on storage +// +// Any pending writes are written out to storage. +// Returns a negative error code on failure. +int lfs1_file_sync(lfs1_t *lfs1, lfs1_file_t *file); + +// Read data from file +// +// Takes a buffer and size indicating where to store the read data. +// Returns the number of bytes read, or a negative error code on failure. +lfs1_ssize_t lfs1_file_read(lfs1_t *lfs1, lfs1_file_t *file, + void *buffer, lfs1_size_t size); + +// Write data to file +// +// Takes a buffer and size indicating the data to write. The file will not +// actually be updated on the storage until either sync or close is called. +// +// Returns the number of bytes written, or a negative error code on failure. +lfs1_ssize_t lfs1_file_write(lfs1_t *lfs1, lfs1_file_t *file, + const void *buffer, lfs1_size_t size); + +// Change the position of the file +// +// The change in position is determined by the offset and whence flag. +// Returns the old position of the file, or a negative error code on failure. +lfs1_soff_t lfs1_file_seek(lfs1_t *lfs1, lfs1_file_t *file, + lfs1_soff_t off, int whence); + +// Truncates the size of the file to the specified size +// +// Returns a negative error code on failure. +int lfs1_file_truncate(lfs1_t *lfs1, lfs1_file_t *file, lfs1_off_t size); + +// Return the position of the file +// +// Equivalent to lfs1_file_seek(lfs1, file, 0, LFS1_SEEK_CUR) +// Returns the position of the file, or a negative error code on failure. +lfs1_soff_t lfs1_file_tell(lfs1_t *lfs1, lfs1_file_t *file); + +// Change the position of the file to the beginning of the file +// +// Equivalent to lfs1_file_seek(lfs1, file, 0, LFS1_SEEK_CUR) +// Returns a negative error code on failure. +int lfs1_file_rewind(lfs1_t *lfs1, lfs1_file_t *file); + +// Return the size of the file +// +// Similar to lfs1_file_seek(lfs1, file, 0, LFS1_SEEK_END) +// Returns the size of the file, or a negative error code on failure. +lfs1_soff_t lfs1_file_size(lfs1_t *lfs1, lfs1_file_t *file); + + +/// Directory operations /// + +// Create a directory +// +// Returns a negative error code on failure. +int lfs1_mkdir(lfs1_t *lfs1, const char *path); + +// Open a directory +// +// Once open a directory can be used with read to iterate over files. +// Returns a negative error code on failure. +int lfs1_dir_open(lfs1_t *lfs1, lfs1_dir_t *dir, const char *path); + +// Close a directory +// +// Releases any allocated resources. +// Returns a negative error code on failure. +int lfs1_dir_close(lfs1_t *lfs1, lfs1_dir_t *dir); + +// Read an entry in the directory +// +// Fills out the info structure, based on the specified file or directory. +// Returns a negative error code on failure. +int lfs1_dir_read(lfs1_t *lfs1, lfs1_dir_t *dir, struct lfs1_info *info); + +// Change the position of the directory +// +// The new off must be a value previous returned from tell and specifies +// an absolute offset in the directory seek. +// +// Returns a negative error code on failure. +int lfs1_dir_seek(lfs1_t *lfs1, lfs1_dir_t *dir, lfs1_off_t off); + +// Return the position of the directory +// +// The returned offset is only meant to be consumed by seek and may not make +// sense, but does indicate the current position in the directory iteration. +// +// Returns the position of the directory, or a negative error code on failure. +lfs1_soff_t lfs1_dir_tell(lfs1_t *lfs1, lfs1_dir_t *dir); + +// Change the position of the directory to the beginning of the directory +// +// Returns a negative error code on failure. +int lfs1_dir_rewind(lfs1_t *lfs1, lfs1_dir_t *dir); + + +/// Miscellaneous littlefs specific operations /// + +// Traverse through all blocks in use by the filesystem +// +// The provided callback will be called with each block address that is +// currently in use by the filesystem. This can be used to determine which +// blocks are in use or how much of the storage is available. +// +// Returns a negative error code on failure. +int lfs1_traverse(lfs1_t *lfs1, int (*cb)(void*, lfs1_block_t), void *data); + +// Prunes any recoverable errors that may have occured in the filesystem +// +// Not needed to be called by user unless an operation is interrupted +// but the filesystem is still mounted. This is already called on first +// allocation. +// +// Returns a negative error code on failure. +int lfs1_deorphan(lfs1_t *lfs1); + + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif diff --git a/lib/littlefs/lfs1_util.c b/lib/littlefs/lfs1_util.c new file mode 100644 index 0000000000..3832a5ddb3 --- /dev/null +++ b/lib/littlefs/lfs1_util.c @@ -0,0 +1,31 @@ +/* + * lfs1 util functions + * + * Copyright (c) 2017, Arm Limited. All rights reserved. + * SPDX-License-Identifier: BSD-3-Clause + */ +#include "lfs1_util.h" + +// Only compile if user does not provide custom config +#ifndef LFS1_CONFIG + + +// Software CRC implementation with small lookup table +void lfs1_crc(uint32_t *restrict crc, const void *buffer, size_t size) { + static const uint32_t rtable[16] = { + 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, + 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, + 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, + 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c, + }; + + const uint8_t *data = buffer; + + for (size_t i = 0; i < size; i++) { + *crc = (*crc >> 4) ^ rtable[(*crc ^ (data[i] >> 0)) & 0xf]; + *crc = (*crc >> 4) ^ rtable[(*crc ^ (data[i] >> 4)) & 0xf]; + } +} + + +#endif diff --git a/lib/littlefs/lfs1_util.h b/lib/littlefs/lfs1_util.h new file mode 100644 index 0000000000..b33b6a7adc --- /dev/null +++ b/lib/littlefs/lfs1_util.h @@ -0,0 +1,186 @@ +/* + * lfs1 utility functions + * + * Copyright (c) 2017, Arm Limited. All rights reserved. + * SPDX-License-Identifier: BSD-3-Clause + */ +#ifndef LFS1_UTIL_H +#define LFS1_UTIL_H + +// Users can override lfs1_util.h with their own configuration by defining +// LFS1_CONFIG as a header file to include (-DLFS1_CONFIG=lfs1_config.h). +// +// If LFS1_CONFIG is used, none of the default utils will be emitted and must be +// provided by the config file. To start I would suggest copying lfs1_util.h and +// modifying as needed. +#ifdef LFS1_CONFIG +#define LFS1_STRINGIZE(x) LFS1_STRINGIZE2(x) +#define LFS1_STRINGIZE2(x) #x +#include LFS1_STRINGIZE(LFS1_CONFIG) +#else + +// System includes +#include +#include +#include + +#ifndef LFS1_NO_MALLOC +#include +#endif +#ifndef LFS1_NO_ASSERT +#include +#endif +#if !defined(LFS1_NO_DEBUG) || !defined(LFS1_NO_WARN) || !defined(LFS1_NO_ERROR) +#include +#endif + +#ifdef __cplusplus +extern "C" +{ +#endif + + +// Macros, may be replaced by system specific wrappers. Arguments to these +// macros must not have side-effects as the macros can be removed for a smaller +// code footprint + +// Logging functions +#ifndef LFS1_NO_DEBUG +#define LFS1_DEBUG(fmt, ...) \ + printf("lfs1 debug:%d: " fmt "\n", __LINE__, __VA_ARGS__) +#else +#define LFS1_DEBUG(fmt, ...) +#endif + +#ifndef LFS1_NO_WARN +#define LFS1_WARN(fmt, ...) \ + printf("lfs1 warn:%d: " fmt "\n", __LINE__, __VA_ARGS__) +#else +#define LFS1_WARN(fmt, ...) +#endif + +#ifndef LFS1_NO_ERROR +#define LFS1_ERROR(fmt, ...) \ + printf("lfs1 error:%d: " fmt "\n", __LINE__, __VA_ARGS__) +#else +#define LFS1_ERROR(fmt, ...) +#endif + +// Runtime assertions +#ifndef LFS1_NO_ASSERT +#define LFS1_ASSERT(test) assert(test) +#else +#define LFS1_ASSERT(test) +#endif + + +// Builtin functions, these may be replaced by more efficient +// toolchain-specific implementations. LFS1_NO_INTRINSICS falls back to a more +// expensive basic C implementation for debugging purposes + +// Min/max functions for unsigned 32-bit numbers +static inline uint32_t lfs1_max(uint32_t a, uint32_t b) { + return (a > b) ? a : b; +} + +static inline uint32_t lfs1_min(uint32_t a, uint32_t b) { + return (a < b) ? a : b; +} + +// Find the next smallest power of 2 less than or equal to a +static inline uint32_t lfs1_npw2(uint32_t a) { +#if !defined(LFS1_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM)) + return 32 - __builtin_clz(a-1); +#else + uint32_t r = 0; + uint32_t s; + a -= 1; + s = (a > 0xffff) << 4; a >>= s; r |= s; + s = (a > 0xff ) << 3; a >>= s; r |= s; + s = (a > 0xf ) << 2; a >>= s; r |= s; + s = (a > 0x3 ) << 1; a >>= s; r |= s; + return (r | (a >> 1)) + 1; +#endif +} + +// Count the number of trailing binary zeros in a +// lfs1_ctz(0) may be undefined +static inline uint32_t lfs1_ctz(uint32_t a) { +#if !defined(LFS1_NO_INTRINSICS) && defined(__GNUC__) + return __builtin_ctz(a); +#else + return lfs1_npw2((a & -a) + 1) - 1; +#endif +} + +// Count the number of binary ones in a +static inline uint32_t lfs1_popc(uint32_t a) { +#if !defined(LFS1_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM)) + return __builtin_popcount(a); +#else + a = a - ((a >> 1) & 0x55555555); + a = (a & 0x33333333) + ((a >> 2) & 0x33333333); + return (((a + (a >> 4)) & 0xf0f0f0f) * 0x1010101) >> 24; +#endif +} + +// Find the sequence comparison of a and b, this is the distance +// between a and b ignoring overflow +static inline int lfs1_scmp(uint32_t a, uint32_t b) { + return (int)(unsigned)(a - b); +} + +// Convert from 32-bit little-endian to native order +static inline uint32_t lfs1_fromle32(uint32_t a) { +#if !defined(LFS1_NO_INTRINSICS) && ( \ + (defined( BYTE_ORDER ) && BYTE_ORDER == ORDER_LITTLE_ENDIAN ) || \ + (defined(__BYTE_ORDER ) && __BYTE_ORDER == __ORDER_LITTLE_ENDIAN ) || \ + (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)) + return a; +#elif !defined(LFS1_NO_INTRINSICS) && ( \ + (defined( BYTE_ORDER ) && BYTE_ORDER == ORDER_BIG_ENDIAN ) || \ + (defined(__BYTE_ORDER ) && __BYTE_ORDER == __ORDER_BIG_ENDIAN ) || \ + (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)) + return __builtin_bswap32(a); +#else + return (((uint8_t*)&a)[0] << 0) | + (((uint8_t*)&a)[1] << 8) | + (((uint8_t*)&a)[2] << 16) | + (((uint8_t*)&a)[3] << 24); +#endif +} + +// Convert to 32-bit little-endian from native order +static inline uint32_t lfs1_tole32(uint32_t a) { + return lfs1_fromle32(a); +} + +// Calculate CRC-32 with polynomial = 0x04c11db7 +void lfs1_crc(uint32_t *crc, const void *buffer, size_t size); + +// Allocate memory, only used if buffers are not provided to littlefs +static inline void *lfs1_malloc(size_t size) { +#ifndef LFS1_NO_MALLOC + return malloc(size); +#else + (void)size; + return NULL; +#endif +} + +// Deallocate memory, only used if buffers are not provided to littlefs +static inline void lfs1_free(void *p) { +#ifndef LFS1_NO_MALLOC + free(p); +#else + (void)p; +#endif +} + + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif +#endif