mirror of
https://github.com/eledio-devices/thirdparty-littlefs.git
synced 2025-10-31 08:42:40 +01:00
1eeb2a6811
Directories still consume two full erase blocks, but now only program the exact on-disk region to store the directory contents. This results in a decent improvement in the amount of data written and read to the device when doing directory operations. Calculating the checksum of dynamically sized data is surprisingly tricky, since the size of the data could also contain errors. For the littlefs, we can assume the data size must fit in an erase block. If the data size is invalid, we can just treat the block as corrupted.
2050 lines
53 KiB
C
2050 lines
53 KiB
C
/*
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* The little filesystem
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*
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* Copyright (c) 2017 Christopher Haster
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* Distributed under the MIT license
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*/
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#include "lfs.h"
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#include "lfs_util.h"
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#include <string.h>
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#include <stdlib.h>
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#include <assert.h>
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/// Caching block device operations ///
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static int lfs_cache_read(lfs_t *lfs, lfs_cache_t *rcache,
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const lfs_cache_t *pcache, lfs_block_t block,
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lfs_off_t off, void *buffer, lfs_size_t size) {
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uint8_t *data = buffer;
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assert(block < lfs->cfg->block_count);
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while (size > 0) {
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if (pcache && block == pcache->block && off >= pcache->off &&
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off < pcache->off + lfs->cfg->prog_size) {
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// is already in pcache?
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lfs_size_t diff = lfs_min(size,
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lfs->cfg->prog_size - (off-pcache->off));
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memcpy(data, &pcache->buffer[off-pcache->off], diff);
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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if (block == rcache->block && off >= rcache->off &&
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off < rcache->off + lfs->cfg->read_size) {
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// is already in rcache?
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lfs_size_t diff = lfs_min(size,
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lfs->cfg->read_size - (off-rcache->off));
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memcpy(data, &rcache->buffer[off-rcache->off], diff);
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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if (off % lfs->cfg->read_size == 0 && size >= lfs->cfg->read_size) {
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// bypass cache?
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lfs_size_t diff = size - (size % lfs->cfg->read_size);
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int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
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if (err) {
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return err;
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}
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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// load to cache, first condition can no longer fail
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rcache->block = block;
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rcache->off = off - (off % lfs->cfg->read_size);
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int err = lfs->cfg->read(lfs->cfg, rcache->block,
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rcache->off, rcache->buffer, lfs->cfg->read_size);
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if (err) {
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return err;
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}
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}
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return 0;
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}
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static int lfs_cache_flush(lfs_t *lfs, lfs_cache_t *cache) {
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if (cache->block != 0xffffffff) {
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int err = lfs->cfg->prog(lfs->cfg, cache->block,
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cache->off, cache->buffer, lfs->cfg->prog_size);
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if (err) {
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return err;
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}
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cache->block = 0xffffffff;
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}
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return 0;
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}
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static int lfs_cache_prog(lfs_t *lfs, lfs_cache_t *cache, lfs_block_t block,
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lfs_off_t off, const void *buffer, lfs_size_t size) {
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const uint8_t *data = buffer;
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assert(block < lfs->cfg->block_count);
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while (size > 0) {
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if (block == cache->block && off >= cache->off &&
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off < cache->off + lfs->cfg->prog_size) {
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// is already in cache?
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lfs_size_t diff = lfs_min(size,
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lfs->cfg->prog_size - (off-cache->off));
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memcpy(&cache->buffer[off-cache->off], data, diff);
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data += diff;
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off += diff;
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size -= diff;
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if (off % lfs->cfg->prog_size == 0) {
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// eagerly flush out cache if we fill up
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int err = lfs_cache_flush(lfs, cache);
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if (err) {
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return err;
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}
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}
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continue;
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}
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// cache must have been flushed, either by programming and
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// entire block or manually flushing the cache
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assert(cache->block == 0xffffffff);
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if (off % lfs->cfg->prog_size == 0 &&
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size >= lfs->cfg->prog_size) {
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// bypass cache?
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lfs_size_t diff = size - (size % lfs->cfg->prog_size);
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int err = lfs->cfg->prog(lfs->cfg, block, off, data, diff);
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if (err) {
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return err;
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}
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data += diff;
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off += diff;
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size -= diff;
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continue;
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}
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// prepare cache, first condition can no longer fail
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cache->block = block;
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cache->off = off - (off % lfs->cfg->prog_size);
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}
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return 0;
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}
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/// General lfs block device operations ///
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static int lfs_read(lfs_t *lfs, lfs_block_t block,
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lfs_off_t off, void *buffer, lfs_size_t size) {
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// if we ever do more than writes to alternating pairs,
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// this may need to consider pcache
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return lfs_cache_read(lfs, &lfs->rcache, NULL,
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block, off, buffer, size);
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}
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static int lfs_prog(lfs_t *lfs, lfs_block_t block,
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lfs_off_t off, const void *buffer, lfs_size_t size) {
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return lfs_cache_prog(lfs, &lfs->pcache,
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block, off, buffer, size);
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}
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static int lfs_erase(lfs_t *lfs, lfs_block_t block) {
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return lfs->cfg->erase(lfs->cfg, block);
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}
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static int lfs_sync(lfs_t *lfs) {
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int err = lfs_cache_flush(lfs, &lfs->pcache);
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if (err) {
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return err;
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}
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return lfs->cfg->sync(lfs->cfg);
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}
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static int lfs_cmp(lfs_t *lfs, lfs_block_t block,
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lfs_off_t off, lfs_size_t size, const void *buffer) {
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const uint8_t *data = buffer;
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for (lfs_off_t i = 0; i < size; i++) {
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uint8_t c;
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int err = lfs_read(lfs, block, off+i, &c, 1);
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if (err) {
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return err;
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}
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if (c != data[i]) {
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return false;
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}
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}
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return true;
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}
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/// Internal operations predeclared here ///
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int lfs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
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static int lfs_pred(lfs_t *lfs, const lfs_block_t dir[2], lfs_dir_t *pdir);
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static int lfs_parent(lfs_t *lfs, const lfs_block_t dir[2],
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lfs_dir_t *parent, lfs_entry_t *entry);
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static int lfs_relocate(lfs_t *lfs,
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const lfs_block_t oldpair[2], const lfs_block_t newpair[2]);
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int lfs_deorphan(lfs_t *lfs);
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/// Block allocator ///
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static int lfs_alloc_lookahead(void *p, lfs_block_t block) {
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lfs_t *lfs = p;
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lfs_block_t off = (block - lfs->free.start) % lfs->cfg->block_count;
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if (off < lfs->cfg->lookahead) {
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lfs->free.lookahead[off / 32] |= 1U << (off % 32);
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}
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return 0;
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}
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static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
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// deorphan if we haven't yet, only needed once after poweron
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if (!lfs->deorphaned) {
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int err = lfs_deorphan(lfs);
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if (err) {
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return err;
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}
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}
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while (true) {
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while (true) {
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// check if we have looked at all blocks since last ack
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if (lfs->free.start + lfs->free.off == lfs->free.end) {
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LFS_WARN("No more free space %d", lfs->free.end);
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return LFS_ERR_NOSPC;
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}
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if (lfs->free.off >= lfs->cfg->lookahead) {
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break;
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}
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lfs_block_t off = lfs->free.off;
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lfs->free.off += 1;
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if (!(lfs->free.lookahead[off / 32] & (1U << (off % 32)))) {
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// found a free block
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*block = (lfs->free.start + off) % lfs->cfg->block_count;
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return 0;
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}
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}
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lfs->free.start += lfs->cfg->lookahead;
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lfs->free.off = 0;
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// find mask of free blocks from tree
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memset(lfs->free.lookahead, 0, lfs->cfg->lookahead/8);
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int err = lfs_traverse(lfs, lfs_alloc_lookahead, lfs);
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if (err) {
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return err;
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}
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}
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}
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static void lfs_alloc_ack(lfs_t *lfs) {
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lfs->free.end = lfs->free.start + lfs->free.off + lfs->cfg->block_count;
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}
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/// Metadata pair and directory operations ///
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static inline void lfs_pairswap(lfs_block_t pair[2]) {
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lfs_block_t t = pair[0];
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pair[0] = pair[1];
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pair[1] = t;
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}
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static inline bool lfs_pairisnull(const lfs_block_t pair[2]) {
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return pair[0] == 0xffffffff || pair[1] == 0xffffffff;
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}
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static inline int lfs_paircmp(
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const lfs_block_t paira[2],
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const lfs_block_t pairb[2]) {
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return !(paira[0] == pairb[0] || paira[1] == pairb[1] ||
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paira[0] == pairb[1] || paira[1] == pairb[0]);
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}
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static inline bool lfs_pairsync(
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const lfs_block_t paira[2],
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const lfs_block_t pairb[2]) {
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return (paira[0] == pairb[0] && paira[1] == pairb[1]) ||
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(paira[0] == pairb[1] && paira[1] == pairb[0]);
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}
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static int lfs_dir_alloc(lfs_t *lfs, lfs_dir_t *dir) {
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// allocate pair of dir blocks
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for (int i = 0; i < 2; i++) {
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int err = lfs_alloc(lfs, &dir->pair[i]);
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if (err) {
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return err;
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}
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}
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// rather than clobbering one of the blocks we just pretend
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// the revision may be valid
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int err = lfs_read(lfs, dir->pair[0], 0, &dir->d.rev, 4);
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if (err) {
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return err;
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}
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// set defaults
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dir->d.rev += 1;
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dir->d.size = sizeof(dir->d)+4;
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dir->d.tail[0] = -1;
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dir->d.tail[1] = -1;
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dir->off = sizeof(dir->d);
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// don't write out yet, let caller take care of that
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return 0;
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}
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static int lfs_dir_fetch(lfs_t *lfs,
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lfs_dir_t *dir, const lfs_block_t pair[2]) {
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// copy out pair, otherwise may be aliasing dir
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const lfs_block_t tpair[2] = {pair[0], pair[1]};
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bool valid = false;
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// check both blocks for the most recent revision
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for (int i = 0; i < 2; i++) {
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struct lfs_disk_dir test;
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int err = lfs_read(lfs, tpair[i], 0, &test, sizeof(test));
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if (err) {
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return err;
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}
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if (valid && lfs_scmp(test.rev, dir->d.rev) < 0) {
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continue;
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}
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if ((0x7fffffff & test.size) > lfs->cfg->block_size) {
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continue;
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}
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uint32_t crc = 0xffffffff;
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crc = lfs_crc(crc, &test, sizeof(test));
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for (lfs_off_t j = sizeof(test); j < (0x7fffffff & test.size); j++) {
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uint8_t data;
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int err = lfs_read(lfs, tpair[i], j, &data, 1);
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if (err) {
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return err;
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}
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crc = lfs_crc(crc, &data, 1);
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}
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if (crc != 0) {
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continue;
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}
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valid = true;
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// setup dir in case it's valid
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dir->pair[0] = tpair[(i+0) % 2];
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dir->pair[1] = tpair[(i+1) % 2];
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dir->off = sizeof(dir->d);
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dir->d = test;
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}
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if (!valid) {
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LFS_ERROR("Corrupted dir pair at %d %d", tpair[0], tpair[1]);
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return LFS_ERR_CORRUPT;
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}
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return 0;
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}
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struct lfs_region {
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lfs_off_t oldoff;
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lfs_size_t oldlen;
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const void *newdata;
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lfs_size_t newlen;
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};
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static int lfs_dir_commit(lfs_t *lfs, lfs_dir_t *dir,
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const struct lfs_region *regions, int count) {
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dir->d.rev += 1;
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lfs_pairswap(dir->pair);
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for (int i = 0; i < count; i++) {
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dir->d.size += regions[i].newlen - regions[i].oldlen;
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}
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const lfs_block_t oldpair[2] = {dir->pair[0], dir->pair[1]};
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bool relocated = false;
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while (true) {
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int err = lfs_erase(lfs, dir->pair[0]);
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if (err) {
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if (err == LFS_ERR_CORRUPT) {
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goto relocate;
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}
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return err;
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}
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uint32_t crc = 0xffffffff;
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crc = lfs_crc(crc, &dir->d, sizeof(dir->d));
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err = lfs_prog(lfs, dir->pair[0], 0, &dir->d, sizeof(dir->d));
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if (err) {
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if (err == LFS_ERR_CORRUPT) {
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goto relocate;
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}
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return err;
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}
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int i = 0;
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lfs_off_t oldoff = sizeof(dir->d);
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lfs_off_t newoff = sizeof(dir->d);
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while (newoff < (0x7fffffff & dir->d.size)-4) {
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if (i < count && regions[i].oldoff == oldoff) {
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crc = lfs_crc(crc, regions[i].newdata, regions[i].newlen);
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int err = lfs_prog(lfs, dir->pair[0],
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newoff, regions[i].newdata, regions[i].newlen);
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if (err) {
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if (err == LFS_ERR_CORRUPT) {
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goto relocate;
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}
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return err;
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}
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oldoff += regions[i].oldlen;
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newoff += regions[i].newlen;
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i += 1;
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} else {
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uint8_t data;
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int err = lfs_read(lfs, oldpair[1], oldoff, &data, 1);
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if (err) {
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return err;
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}
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crc = lfs_crc(crc, &data, 1);
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err = lfs_prog(lfs, dir->pair[0], newoff, &data, 1);
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if (err) {
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if (err == LFS_ERR_CORRUPT) {
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goto relocate;
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}
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return err;
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}
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oldoff += 1;
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newoff += 1;
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}
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}
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err = lfs_prog(lfs, dir->pair[0], newoff, &crc, 4);
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if (err) {
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if (err == LFS_ERR_CORRUPT) {
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goto relocate;
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}
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return err;
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}
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err = lfs_sync(lfs);
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if (err) {
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if (err == LFS_ERR_CORRUPT) {
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goto relocate;
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}
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return err;
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}
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// successful commit
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if (relocated) {
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LFS_DEBUG("Relocating %d %d to %d %d",
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oldpair[0], oldpair[1], dir->pair[0], dir->pair[1]);
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return lfs_relocate(lfs, oldpair, dir->pair);
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}
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return 0;
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relocate:
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LFS_DEBUG("Bad block at %d", dir->pair[0]);
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// drop caches and prepare to relocate block
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relocated = true;
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lfs->pcache.block = 0xffffffff;
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// can't relocate superblock, filesystem is now frozen
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if (lfs_paircmp(oldpair, (const lfs_block_t[2]){0, 1}) == 0) {
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LFS_WARN("Superblock %d has become unwritable", oldpair[0]);
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return LFS_ERR_CORRUPT;
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}
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// relocate half of pair
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err = lfs_alloc(lfs, &dir->pair[0]);
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if (err) {
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return err;
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}
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}
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}
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static int lfs_dir_update(lfs_t *lfs, lfs_dir_t *dir,
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const lfs_entry_t *entry, const void *data) {
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return lfs_dir_commit(lfs, dir, (struct lfs_region[]){
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{entry->off, sizeof(entry->d), &entry->d, sizeof(entry->d)},
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{entry->off+sizeof(entry->d), entry->d.len-sizeof(entry->d),
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data, entry->d.len-sizeof(entry->d)}
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}, data ? 2 : 1);
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}
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static int lfs_dir_append(lfs_t *lfs, lfs_dir_t *dir,
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lfs_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 + entry->d.len <= lfs->cfg->block_size) {
|
|
entry->off = dir->d.size - 4;
|
|
return lfs_dir_commit(lfs, dir, (struct lfs_region[]){
|
|
{entry->off, 0, &entry->d, sizeof(entry->d)},
|
|
{entry->off, 0, data, entry->d.len - sizeof(entry->d)}
|
|
}, 2);
|
|
}
|
|
|
|
// we need to allocate a new dir block
|
|
if (!(0x80000000 & dir->d.size)) {
|
|
lfs_dir_t newdir;
|
|
int err = lfs_dir_alloc(lfs, &newdir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
newdir.d.tail[0] = dir->d.tail[0];
|
|
newdir.d.tail[1] = dir->d.tail[1];
|
|
entry->off = newdir.d.size - 4;
|
|
err = lfs_dir_commit(lfs, &newdir, (struct lfs_region[]){
|
|
{entry->off, 0, &entry->d, sizeof(entry->d)},
|
|
{entry->off, 0, data, entry->d.len - sizeof(entry->d)}
|
|
}, 2);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir->d.size |= 0x80000000;
|
|
dir->d.tail[0] = newdir.pair[0];
|
|
dir->d.tail[1] = newdir.pair[1];
|
|
return lfs_dir_commit(lfs, dir, NULL, 0);
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int lfs_dir_remove(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
|
|
// either shift out the one entry or remove the whole dir block
|
|
if (dir->d.size == sizeof(dir->d)+4) {
|
|
lfs_dir_t pdir;
|
|
int res = lfs_pred(lfs, dir->pair, &pdir);
|
|
if (res < 0) {
|
|
return res;
|
|
}
|
|
|
|
if (!(pdir.d.size & 0x80000000)) {
|
|
return lfs_dir_commit(lfs, dir, (struct lfs_region[]){
|
|
{entry->off, entry->d.len, NULL, 0},
|
|
}, 1);
|
|
} else {
|
|
pdir.d.tail[0] = dir->d.tail[0];
|
|
pdir.d.tail[1] = dir->d.tail[1];
|
|
return lfs_dir_commit(lfs, dir, NULL, 0);
|
|
}
|
|
} else {
|
|
return lfs_dir_commit(lfs, dir, (struct lfs_region[]){
|
|
{entry->off, entry->d.len, NULL, 0},
|
|
}, 1);
|
|
}
|
|
}
|
|
|
|
static int lfs_dir_next(lfs_t *lfs, lfs_dir_t *dir, lfs_entry_t *entry) {
|
|
while (dir->off + sizeof(entry->d) > (0x7fffffff & dir->d.size)-4) {
|
|
if (!(0x80000000 & dir->d.size)) {
|
|
entry->off = dir->off;
|
|
return LFS_ERR_NOENT;
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir->off = sizeof(dir->d);
|
|
dir->pos += sizeof(dir->d) + 4;
|
|
}
|
|
|
|
int err = lfs_read(lfs, dir->pair[0], dir->off,
|
|
&entry->d, sizeof(entry->d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir->off += entry->d.len;
|
|
dir->pos += entry->d.len;
|
|
entry->off = dir->off - entry->d.len;
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_dir_find(lfs_t *lfs, lfs_dir_t *dir,
|
|
lfs_entry_t *entry, const char **path) {
|
|
const char *pathname = *path;
|
|
size_t pathlen;
|
|
|
|
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;
|
|
}
|
|
|
|
// find path
|
|
while (true) {
|
|
int err = lfs_dir_next(lfs, dir, entry);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (((0xff & entry->d.type) != LFS_TYPE_REG &&
|
|
(0xff & entry->d.type) != LFS_TYPE_DIR) ||
|
|
entry->d.len - sizeof(entry->d) != pathlen) {
|
|
continue;
|
|
}
|
|
|
|
int ret = lfs_cmp(lfs, dir->pair[0],
|
|
entry->off + sizeof(entry->d), pathlen, pathname);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
// found match
|
|
if (ret == true) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
pathname += pathlen;
|
|
pathname += strspn(pathname, "/");
|
|
if (pathname[0] == '\0') {
|
|
return 0;
|
|
}
|
|
|
|
// continue on if we hit a directory
|
|
if (entry->d.type != LFS_TYPE_DIR) {
|
|
return LFS_ERR_NOTDIR;
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, entry->d.u.dir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
*path = pathname;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/// Top level directory operations ///
|
|
int lfs_mkdir(lfs_t *lfs, const char *path) {
|
|
// fetch parent directory
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err != LFS_ERR_NOENT) {
|
|
return err ? err : LFS_ERR_EXISTS;
|
|
}
|
|
|
|
// build up new directory
|
|
lfs_alloc_ack(lfs);
|
|
|
|
lfs_dir_t dir;
|
|
err = lfs_dir_alloc(lfs, &dir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
dir.d.tail[0] = cwd.d.tail[0];
|
|
dir.d.tail[1] = cwd.d.tail[1];
|
|
|
|
err = lfs_dir_commit(lfs, &dir, NULL, 0);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
entry.d.type = LFS_TYPE_DIR;
|
|
entry.d.len = sizeof(entry.d) + 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 = lfs_dir_append(lfs, &cwd, &entry, path);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_alloc_ack(lfs);
|
|
return 0;
|
|
}
|
|
|
|
int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path) {
|
|
dir->pair[0] = lfs->root[0];
|
|
dir->pair[1] = lfs->root[1];
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->pair);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (strspn(path, "/.") == strlen(path)) {
|
|
// can only be something like '/././../.'
|
|
dir->head[0] = dir->pair[0];
|
|
dir->head[1] = dir->pair[1];
|
|
dir->pos = sizeof(dir->d) - 2;
|
|
dir->off = sizeof(dir->d);
|
|
return 0;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, dir, &entry, &path);
|
|
if (err) {
|
|
return err;
|
|
} else if (entry.d.type != LFS_TYPE_DIR) {
|
|
return LFS_ERR_NOTDIR;
|
|
}
|
|
|
|
err = lfs_dir_fetch(lfs, 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);
|
|
return 0;
|
|
}
|
|
|
|
int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir) {
|
|
// do nothing, dir is always synchronized
|
|
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 == sizeof(dir->d) - 2) {
|
|
info->type = LFS_TYPE_DIR;
|
|
strcpy(info->name, ".");
|
|
dir->pos += 1;
|
|
return 1;
|
|
} else if (dir->pos == sizeof(dir->d) - 1) {
|
|
info->type = LFS_TYPE_DIR;
|
|
strcpy(info->name, "..");
|
|
dir->pos += 1;
|
|
return 1;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
while (true) {
|
|
int err = lfs_dir_next(lfs, dir, &entry);
|
|
if (err) {
|
|
return (err == LFS_ERR_NOENT) ? 0 : err;
|
|
}
|
|
|
|
if ((0xff & entry.d.type) == LFS_TYPE_REG ||
|
|
(0xff & entry.d.type) == LFS_TYPE_DIR) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
info->type = entry.d.type & 0xff;
|
|
if (info->type == LFS_TYPE_REG) {
|
|
info->size = entry.d.u.file.size;
|
|
}
|
|
|
|
int err = lfs_read(lfs, dir->pair[0], entry.off + sizeof(entry.d),
|
|
info->name, entry.d.len - sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
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;
|
|
}
|
|
dir->pos = off;
|
|
|
|
while (off > (0x7fffffff & dir->d.size)) {
|
|
off -= 0x7fffffff & dir->d.size;
|
|
if (!(0x80000000 & dir->d.size)) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, dir, dir->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
dir->off = off;
|
|
return 0;
|
|
}
|
|
|
|
lfs_soff_t lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir) {
|
|
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, 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 lfs_index(lfs_t *lfs, lfs_off_t *off) {
|
|
lfs_off_t i = 0;
|
|
lfs_size_t words = lfs->cfg->block_size / 4;
|
|
|
|
while (*off >= lfs->cfg->block_size) {
|
|
i += 1;
|
|
*off -= lfs->cfg->block_size;
|
|
*off += 4*lfs_min(lfs_ctz(i)+1, words-1);
|
|
}
|
|
|
|
return i;
|
|
}
|
|
|
|
static int lfs_index_find(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 = -1;
|
|
*off = 0;
|
|
return 0;
|
|
}
|
|
|
|
lfs_off_t current = lfs_index(lfs, &(lfs_off_t){size-1});
|
|
lfs_off_t target = lfs_index(lfs, &pos);
|
|
lfs_size_t words = lfs->cfg->block_size / 4;
|
|
|
|
while (current > target) {
|
|
lfs_size_t skip = lfs_min(
|
|
lfs_npw2(current-target+1) - 1,
|
|
lfs_min(lfs_ctz(current)+1, words-1) - 1);
|
|
|
|
int err = lfs_cache_read(lfs, rcache, pcache, head, 4*skip, &head, 4);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
current -= 1 << skip;
|
|
}
|
|
|
|
*block = head;
|
|
*off = pos;
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_index_extend(lfs_t *lfs,
|
|
lfs_cache_t *rcache, lfs_cache_t *pcache,
|
|
lfs_block_t head, lfs_size_t size,
|
|
lfs_off_t *block, lfs_block_t *off) {
|
|
while (true) {
|
|
// go ahead and grab a block
|
|
int err = lfs_alloc(lfs, block);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_erase(lfs, *block);
|
|
if (err) {
|
|
if (err == LFS_ERR_CORRUPT) {
|
|
goto relocate;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
if (size == 0) {
|
|
*off = 0;
|
|
return 0;
|
|
}
|
|
|
|
size -= 1;
|
|
lfs_off_t index = lfs_index(lfs, &size);
|
|
size += 1;
|
|
|
|
// just copy out the last block if it is incomplete
|
|
if (size != lfs->cfg->block_size) {
|
|
for (lfs_off_t i = 0; i < size; i++) {
|
|
uint8_t data;
|
|
int err = lfs_cache_read(lfs, rcache, NULL, head, i, &data, 1);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_cache_prog(lfs, pcache, *block, i, &data, 1);
|
|
if (err) {
|
|
if (err == LFS_ERR_CORRUPT) {
|
|
goto relocate;
|
|
}
|
|
return err;
|
|
}
|
|
}
|
|
|
|
*off = size;
|
|
return 0;
|
|
}
|
|
|
|
// append block
|
|
index += 1;
|
|
lfs_size_t words = lfs->cfg->block_size / 4;
|
|
lfs_size_t skips = lfs_min(lfs_ctz(index)+1, words-1);
|
|
|
|
for (lfs_off_t i = 0; i < skips; i++) {
|
|
int err = lfs_cache_prog(lfs, pcache, *block, 4*i, &head, 4);
|
|
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);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
*off = 4*skips;
|
|
return 0;
|
|
|
|
relocate:
|
|
LFS_DEBUG("Bad block at %d", *block);
|
|
|
|
// just clear cache and try a new block
|
|
pcache->block = 0xffffffff;
|
|
}
|
|
}
|
|
|
|
static int lfs_index_traverse(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_index(lfs, &(lfs_off_t){size-1});
|
|
|
|
while (true) {
|
|
int err = cb(data, head);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (index == 0) {
|
|
return 0;
|
|
}
|
|
|
|
err = lfs_cache_read(lfs, rcache, pcache, head, 0, &head, 4);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
index -= 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/// Top level file operations ///
|
|
int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
|
|
const char *path, int flags) {
|
|
// allocate entry for file if it doesn't exist
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err && err != LFS_ERR_NOENT) {
|
|
return err;
|
|
}
|
|
|
|
if (err == LFS_ERR_NOENT) {
|
|
if (!(flags & LFS_O_CREAT)) {
|
|
return LFS_ERR_NOENT;
|
|
}
|
|
|
|
// create entry to remember name
|
|
entry.d.type = LFS_TYPE_REG;
|
|
entry.d.len = sizeof(entry.d) + strlen(path);
|
|
entry.d.u.file.head = -1;
|
|
entry.d.u.file.size = 0;
|
|
err = lfs_dir_append(lfs, &cwd, &entry, path);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
} else if (entry.d.type == LFS_TYPE_DIR) {
|
|
return LFS_ERR_ISDIR;
|
|
} else if (flags & LFS_O_EXCL) {
|
|
return LFS_ERR_EXISTS;
|
|
}
|
|
|
|
// setup file struct
|
|
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 & LFS_O_TRUNC) {
|
|
file->head = -1;
|
|
file->size = 0;
|
|
}
|
|
|
|
// allocate buffer if needed
|
|
file->cache.block = 0xffffffff;
|
|
if (lfs->cfg->file_buffer) {
|
|
file->cache.buffer = lfs->cfg->file_buffer;
|
|
} else if ((file->flags & 3) == LFS_O_RDONLY) {
|
|
file->cache.buffer = malloc(lfs->cfg->read_size);
|
|
if (!file->cache.buffer) {
|
|
return LFS_ERR_NOMEM;
|
|
}
|
|
} else {
|
|
file->cache.buffer = malloc(lfs->cfg->prog_size);
|
|
if (!file->cache.buffer) {
|
|
return LFS_ERR_NOMEM;
|
|
}
|
|
}
|
|
|
|
// add to list of files
|
|
file->next = lfs->files;
|
|
lfs->files = file;
|
|
|
|
return 0;
|
|
}
|
|
|
|
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 (!lfs->cfg->file_buffer) {
|
|
free(file->cache.buffer);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
|
|
if (file->flags & LFS_F_READING) {
|
|
// just drop read cache
|
|
file->cache.block = 0xffffffff;
|
|
file->flags &= ~LFS_F_READING;
|
|
}
|
|
|
|
if (file->flags & LFS_F_WRITING) {
|
|
lfs_off_t pos = file->pos;
|
|
|
|
// copy over anything after current branch
|
|
lfs_file_t orig = {
|
|
.head = file->head,
|
|
.size = file->size,
|
|
.flags = LFS_O_RDONLY,
|
|
.pos = file->pos,
|
|
.cache = lfs->rcache,
|
|
};
|
|
lfs->rcache.block = 0xffffffff;
|
|
|
|
while (file->pos < file->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
|
|
int err = lfs_cache_flush(lfs, &file->cache);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// actual file updates
|
|
file->head = file->block;
|
|
file->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) {
|
|
int err = lfs_file_flush(lfs, file);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if ((file->flags & LFS_F_DIRTY) && !lfs_pairisnull(file->pair)) {
|
|
// update dir entry
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, file->pair);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry = {.off = file->poff};
|
|
err = lfs_read(lfs, cwd.pair[0], entry.off,
|
|
&entry.d, sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
if (entry.d.type != LFS_TYPE_REG) {
|
|
// sanity check valid entry
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
entry.d.u.file.head = file->head;
|
|
entry.d.u.file.size = file->size;
|
|
|
|
err = lfs_dir_update(lfs, &cwd, &entry, NULL);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
file->flags &= ~LFS_F_DIRTY;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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_INVAL;
|
|
}
|
|
|
|
if (file->flags & LFS_F_WRITING) {
|
|
// flush out any writes
|
|
int err = lfs_file_flush(lfs, file);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
size = lfs_min(size, file->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) {
|
|
int err = lfs_index_find(lfs, &file->cache, NULL,
|
|
file->head, file->size,
|
|
file->pos, &file->block, &file->off);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
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_INVAL;
|
|
}
|
|
|
|
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->size) {
|
|
file->pos = file->size;
|
|
}
|
|
|
|
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_WRITING)) {
|
|
// find out which block we're extending from
|
|
int err = lfs_index_find(lfs, &file->cache, NULL,
|
|
file->head, file->size,
|
|
file->pos, &file->block, &file->off);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// mark cache as dirty since we may have read data into it
|
|
file->cache.block = 0xffffffff;
|
|
file->flags |= LFS_F_WRITING;
|
|
}
|
|
|
|
// extend file with new blocks
|
|
lfs_alloc_ack(lfs);
|
|
int err = lfs_index_extend(lfs, &lfs->rcache, &file->cache,
|
|
file->block, file->pos,
|
|
&file->block, &file->off);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
// 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,
|
|
file->block, file->off, data, diff);
|
|
if (err) {
|
|
if (err == LFS_ERR_CORRUPT) {
|
|
goto relocate;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
break;
|
|
relocate:
|
|
LFS_DEBUG("Bad block at %d", file->block);
|
|
|
|
// just relocate what exists into new block
|
|
lfs_block_t nblock;
|
|
err = lfs_alloc(lfs, &nblock);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// either read from dirty cache or disk
|
|
for (lfs_off_t i = 0; i < file->off; i++) {
|
|
uint8_t data;
|
|
if (file->cache.block == file->block && i >= file->cache.off) {
|
|
data = file->cache.buffer[i - file->cache.off];
|
|
} else {
|
|
// just read from disk
|
|
err = lfs_read(lfs, file->block, i, &data, 1);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
err = lfs_prog(lfs, 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;
|
|
}
|
|
|
|
file->pos += diff;
|
|
file->off += diff;
|
|
data += diff;
|
|
nsize -= diff;
|
|
|
|
lfs_alloc_ack(lfs);
|
|
}
|
|
|
|
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
|
|
lfs_off_t pos = file->pos;
|
|
|
|
if (whence == LFS_SEEK_SET) {
|
|
file->pos = off;
|
|
} else if (whence == LFS_SEEK_CUR) {
|
|
file->pos = file->pos + off;
|
|
} else if (whence == LFS_SEEK_END) {
|
|
file->pos = file->size + off;
|
|
}
|
|
|
|
return pos;
|
|
}
|
|
|
|
lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file) {
|
|
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) {
|
|
return lfs_max(file->pos, file->size);
|
|
}
|
|
|
|
|
|
/// General fs oprations ///
|
|
int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
memset(info, 0, sizeof(*info));
|
|
info->type = entry.d.type & 0xff;
|
|
if (info->type == LFS_TYPE_REG) {
|
|
info->size = entry.d.u.file.size;
|
|
}
|
|
|
|
err = lfs_read(lfs, cwd.pair[0], entry.off + sizeof(entry.d),
|
|
info->name, entry.d.len - sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int lfs_remove(lfs_t *lfs, const char *path) {
|
|
lfs_dir_t cwd;
|
|
int err = lfs_dir_fetch(lfs, &cwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t entry;
|
|
err = lfs_dir_find(lfs, &cwd, &entry, &path);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_dir_t dir;
|
|
if (entry.d.type == LFS_TYPE_DIR) {
|
|
// must be empty before removal, checking size
|
|
// without masking top bit checks for any case where
|
|
// dir is not empty
|
|
int err = lfs_dir_fetch(lfs, &dir, entry.d.u.dir);
|
|
if (err) {
|
|
return err;
|
|
} else if (dir.d.size != sizeof(dir.d)+4) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
}
|
|
|
|
// remove the entry
|
|
err = lfs_dir_remove(lfs, &cwd, &entry);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// shift over any files that are affected
|
|
for (lfs_file_t *f = lfs->files; f; f = f->next) {
|
|
if (lfs_paircmp(f->pair, cwd.pair) == 0) {
|
|
if (f->poff == entry.off) {
|
|
f->pair[0] = 0xffffffff;
|
|
f->pair[1] = 0xffffffff;
|
|
} else if (f->poff > entry.off) {
|
|
f->poff -= entry.d.len;
|
|
}
|
|
}
|
|
}
|
|
|
|
// if we were a directory, just run a deorphan step, this should
|
|
// collect us, although is expensive
|
|
if (entry.d.type == LFS_TYPE_DIR) {
|
|
int err = lfs_deorphan(lfs);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
|
|
// find old entry
|
|
lfs_dir_t oldcwd;
|
|
int err = lfs_dir_fetch(lfs, &oldcwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t oldentry;
|
|
err = lfs_dir_find(lfs, &oldcwd, &oldentry, &oldpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// allocate new entry
|
|
lfs_dir_t newcwd;
|
|
err = lfs_dir_fetch(lfs, &newcwd, lfs->root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_entry_t preventry;
|
|
err = lfs_dir_find(lfs, &newcwd, &preventry, &newpath);
|
|
if (err && err != LFS_ERR_NOENT) {
|
|
return err;
|
|
}
|
|
bool prevexists = (err != LFS_ERR_NOENT);
|
|
|
|
// must have same type
|
|
if (prevexists && preventry.d.type != oldentry.d.type) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
lfs_dir_t dir;
|
|
if (prevexists && preventry.d.type == LFS_TYPE_DIR) {
|
|
// must be empty before removal, checking size
|
|
// without masking top bit checks for any case where
|
|
// dir is not empty
|
|
int err = lfs_dir_fetch(lfs, &dir, preventry.d.u.dir);
|
|
if (err) {
|
|
return err;
|
|
} else if (dir.d.size != sizeof(dir.d)+4) {
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
}
|
|
|
|
// move to new location
|
|
lfs_entry_t newentry = preventry;
|
|
newentry.d = oldentry.d;
|
|
newentry.d.len = sizeof(newentry.d) + strlen(newpath);
|
|
|
|
if (prevexists) {
|
|
int err = lfs_dir_update(lfs, &newcwd, &newentry, newpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
} else {
|
|
int err = lfs_dir_append(lfs, &newcwd, &newentry, newpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
// fetch again in case newcwd == oldcwd
|
|
err = lfs_dir_fetch(lfs, &oldcwd, oldcwd.pair);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_dir_find(lfs, &oldcwd, &oldentry, &oldpath);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// remove from old location
|
|
err = lfs_dir_remove(lfs, &oldcwd, &oldentry);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// shift over any files that are affected
|
|
for (lfs_file_t *f = lfs->files; f; f = f->next) {
|
|
if (lfs_paircmp(f->pair, oldcwd.pair) == 0) {
|
|
if (f->poff == oldentry.off) {
|
|
f->pair[0] = 0xffffffff;
|
|
f->pair[1] = 0xffffffff;
|
|
} else if (f->poff > oldentry.off) {
|
|
f->poff -= oldentry.d.len;
|
|
}
|
|
}
|
|
}
|
|
|
|
// if we were a directory, just run a deorphan step, this should
|
|
// collect us, although is expensive
|
|
if (prevexists && preventry.d.type == LFS_TYPE_DIR) {
|
|
int err = lfs_deorphan(lfs);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/// Filesystem operations ///
|
|
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 = 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 = malloc(lfs->cfg->prog_size);
|
|
if (!lfs->pcache.buffer) {
|
|
return LFS_ERR_NOMEM;
|
|
}
|
|
}
|
|
|
|
// setup lookahead
|
|
if (lfs->cfg->lookahead_buffer) {
|
|
lfs->free.lookahead = lfs->cfg->lookahead_buffer;
|
|
} else {
|
|
lfs->free.lookahead = malloc(lfs->cfg->lookahead/8);
|
|
if (!lfs->free.lookahead) {
|
|
return LFS_ERR_NOMEM;
|
|
}
|
|
}
|
|
|
|
// setup default state
|
|
lfs->root[0] = 0xffffffff;
|
|
lfs->root[1] = 0xffffffff;
|
|
lfs->files = NULL;
|
|
lfs->deorphaned = false;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_deinit(lfs_t *lfs) {
|
|
// free allocated memory
|
|
if (!lfs->cfg->read_buffer) {
|
|
free(lfs->rcache.buffer);
|
|
}
|
|
|
|
if (!lfs->cfg->prog_buffer) {
|
|
free(lfs->pcache.buffer);
|
|
}
|
|
|
|
if (!lfs->cfg->lookahead_buffer) {
|
|
free(lfs->free.lookahead);
|
|
}
|
|
|
|
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.lookahead, 0, lfs->cfg->lookahead/8);
|
|
lfs->free.start = 0;
|
|
lfs->free.off = 0;
|
|
lfs->free.end = lfs->free.start + lfs->cfg->block_count;
|
|
|
|
// create superblock dir
|
|
lfs_alloc_ack(lfs);
|
|
lfs_dir_t superdir;
|
|
err = lfs_dir_alloc(lfs, &superdir);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// write root directory
|
|
lfs_dir_t root;
|
|
err = lfs_dir_alloc(lfs, &root);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
err = lfs_dir_commit(lfs, &root, NULL, 0);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs->root[0] = root.pair[0];
|
|
lfs->root[1] = root.pair[1];
|
|
|
|
// write superblocks
|
|
lfs_superblock_t superblock = {
|
|
.off = sizeof(superdir.d),
|
|
.d.type = LFS_TYPE_SUPERBLOCK,
|
|
.d.len = sizeof(superblock.d),
|
|
.d.version = 0x00000001,
|
|
.d.magic = {"littlefs"},
|
|
.d.block_size = lfs->cfg->block_size,
|
|
.d.block_count = lfs->cfg->block_count,
|
|
.d.root = {lfs->root[0], lfs->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
|
|
bool valid = false;
|
|
for (int i = 0; i < 2; i++) {
|
|
int err = lfs_dir_commit(lfs, &superdir, (struct lfs_region[]){
|
|
{sizeof(superdir.d), sizeof(superblock.d),
|
|
&superblock.d, sizeof(superblock.d)}
|
|
}, 1);
|
|
if (err && err != LFS_ERR_CORRUPT) {
|
|
return err;
|
|
}
|
|
|
|
valid = valid || !err;
|
|
}
|
|
|
|
if (!valid) {
|
|
return LFS_ERR_CORRUPT;
|
|
}
|
|
|
|
// sanity check that fetch works
|
|
err = lfs_dir_fetch(lfs, &superdir, (const lfs_block_t[2]){0, 1});
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
lfs_alloc_ack(lfs);
|
|
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.start = -lfs->cfg->lookahead;
|
|
lfs->free.off = lfs->cfg->lookahead;
|
|
lfs->free.end = lfs->free.start + lfs->cfg->block_count;
|
|
|
|
// load superblock
|
|
lfs_dir_t dir;
|
|
lfs_superblock_t superblock;
|
|
err = lfs_dir_fetch(lfs, &dir, (const lfs_block_t[2]){0, 1});
|
|
if (!err) {
|
|
err = lfs_read(lfs, dir.pair[0],
|
|
sizeof(dir.d), &superblock.d, sizeof(superblock.d));
|
|
|
|
lfs->root[0] = superblock.d.root[0];
|
|
lfs->root[1] = superblock.d.root[1];
|
|
}
|
|
|
|
if (err == LFS_ERR_CORRUPT ||
|
|
memcmp(superblock.d.magic, "littlefs", 8) != 0) {
|
|
LFS_ERROR("Invalid superblock at %d %d", dir.pair[0], dir.pair[1]);
|
|
return LFS_ERR_CORRUPT;
|
|
}
|
|
|
|
if (superblock.d.version > 0x0000ffff) {
|
|
LFS_ERROR("Invalid version %d.%d\n",
|
|
0xffff & (superblock.d.version >> 16),
|
|
0xffff & (superblock.d.version >> 0));
|
|
return LFS_ERR_INVAL;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
int lfs_unmount(lfs_t *lfs) {
|
|
return lfs_deinit(lfs);
|
|
}
|
|
|
|
|
|
/// Littlefs specific operations ///
|
|
int lfs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data) {
|
|
if (lfs_pairisnull(lfs->root)) {
|
|
return 0;
|
|
}
|
|
|
|
// iterate over metadata pairs
|
|
lfs_dir_t dir;
|
|
lfs_entry_t entry;
|
|
lfs_block_t cwd[2] = {0, 1};
|
|
|
|
while (true) {
|
|
for (int i = 0; i < 2; i++) {
|
|
int err = cb(data, cwd[i]);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, &dir, cwd);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// iterate over contents
|
|
while (dir.off + sizeof(entry.d) <= (0x7fffffff & dir.d.size)-4) {
|
|
int err = lfs_read(lfs, dir.pair[0], dir.off,
|
|
&entry.d, sizeof(entry.d));
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
dir.off += entry.d.len;
|
|
if ((0xf & entry.d.type) == LFS_TYPE_REG) {
|
|
int err = lfs_index_traverse(lfs, &lfs->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 (lfs_pairisnull(cwd)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// iterate over any open files
|
|
for (lfs_file_t *f = lfs->files; f; f = f->next) {
|
|
if (f->flags & LFS_F_DIRTY) {
|
|
int err = lfs_index_traverse(lfs, &lfs->rcache, &f->cache,
|
|
f->head, f->size, cb, data);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (f->flags & LFS_F_WRITING) {
|
|
int err = lfs_index_traverse(lfs, &lfs->rcache, &f->cache,
|
|
f->block, f->pos, cb, data);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int lfs_pred(lfs_t *lfs, const lfs_block_t dir[2], lfs_dir_t *pdir) {
|
|
if (lfs_pairisnull(lfs->root)) {
|
|
return 0;
|
|
}
|
|
|
|
// iterate over all directory directory entries
|
|
int err = lfs_dir_fetch(lfs, pdir, (const lfs_block_t[2]){0, 1});
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
while (!lfs_pairisnull(pdir->d.tail)) {
|
|
if (lfs_paircmp(pdir->d.tail, dir) == 0) {
|
|
return true;
|
|
}
|
|
|
|
int err = lfs_dir_fetch(lfs, pdir, pdir->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int lfs_parent(lfs_t *lfs, const lfs_block_t dir[2],
|
|
lfs_dir_t *parent, lfs_entry_t *entry) {
|
|
if (lfs_pairisnull(lfs->root)) {
|
|
return 0;
|
|
}
|
|
|
|
parent->d.tail[0] = 0;
|
|
parent->d.tail[1] = 1;
|
|
|
|
// iterate over all directory directory entries
|
|
while (!lfs_pairisnull(parent->d.tail)) {
|
|
int err = lfs_dir_fetch(lfs, parent, parent->d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
while (true) {
|
|
int err = lfs_dir_next(lfs, parent, entry);
|
|
if (err && err != LFS_ERR_NOENT) {
|
|
return err;
|
|
}
|
|
|
|
if (err == LFS_ERR_NOENT) {
|
|
break;
|
|
}
|
|
|
|
if (((0xf & entry->d.type) == LFS_TYPE_DIR) &&
|
|
lfs_paircmp(entry->d.u.dir, dir) == 0) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int lfs_relocate(lfs_t *lfs,
|
|
const lfs_block_t oldpair[2], const lfs_block_t newpair[2]) {
|
|
// find parent
|
|
lfs_dir_t parent;
|
|
lfs_entry_t entry;
|
|
int res = lfs_parent(lfs, 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 = lfs_dir_update(lfs, &parent, &entry, NULL);
|
|
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_deorphan(lfs);
|
|
}
|
|
|
|
// find pred
|
|
res = lfs_pred(lfs, 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[0] = newpair[0];
|
|
|
|
return lfs_dir_commit(lfs, &parent, NULL, 0);
|
|
}
|
|
|
|
// couldn't find dir, must be new
|
|
return 0;
|
|
}
|
|
|
|
int lfs_deorphan(lfs_t *lfs) {
|
|
lfs->deorphaned = true;
|
|
if (lfs_pairisnull(lfs->root)) {
|
|
return 0;
|
|
}
|
|
|
|
lfs_dir_t pdir;
|
|
lfs_dir_t cdir;
|
|
|
|
// skip superblock
|
|
int err = lfs_dir_fetch(lfs, &pdir, (const lfs_block_t[2]){0, 1});
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// iterate over all directories
|
|
while (!lfs_pairisnull(pdir.d.tail)) {
|
|
int err = lfs_dir_fetch(lfs, &cdir, pdir.d.tail);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
// only check head blocks
|
|
if (!(0x80000000 & pdir.d.size)) {
|
|
// check if we have a parent
|
|
lfs_dir_t parent;
|
|
lfs_entry_t entry;
|
|
int res = lfs_parent(lfs, pdir.d.tail, &parent, &entry);
|
|
if (res < 0) {
|
|
return res;
|
|
}
|
|
|
|
if (!res) {
|
|
// we are an orphan
|
|
LFS_DEBUG("Orphan %d %d", pdir.d.tail[0], pdir.d.tail[1]);
|
|
|
|
pdir.d.tail[0] = cdir.d.tail[0];
|
|
pdir.d.tail[1] = cdir.d.tail[1];
|
|
|
|
err = lfs_dir_commit(lfs, &pdir, NULL, 0);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
if (!lfs_pairsync(entry.d.u.dir, pdir.d.tail)) {
|
|
// we have desynced
|
|
LFS_DEBUG("Desync %d %d", 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 = lfs_dir_commit(lfs, &pdir, NULL, 0);
|
|
if (err) {
|
|
return err;
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
memcpy(&pdir, &cdir, sizeof(pdir));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|