From 34b5b395514dbb245ae3dda3f0bb67564afbebcb Mon Sep 17 00:00:00 2001 From: Christopher Haster Date: Sun, 13 Nov 2022 13:09:21 -0600 Subject: [PATCH] Added lfs_fs_grow for growing the filesystem to a different block_count The initial implementation for this was provided by kaetemi, originally as a mount flag. However, it has been modified here to be self-contained in an explicit runtime function that can be called after mount. The reasons for an explicit function: 1. lfs_mount stays a strictly readonly operation, and avoids pulling in all of the write machinery. 2. filesystem-wide operations such as lfs_fs_grow can be a bit risky, and irreversable. The action of growing the filesystem should be very intentional. --- One concern with this change is that this will be the first function that changes metadata in the superblock. This might break tools that expect the first valid superblock entry to contain the most recent metadata. --- lfs.c | 53 ++++++++++++++++++ lfs.h | 10 ++++ tests/test_superblocks.toml | 105 ++++++++++++++++++++++++++++++++++++ 3 files changed, 168 insertions(+) diff --git a/lfs.c b/lfs.c index 8dfbedcc..e46b9867 100644 --- a/lfs.c +++ b/lfs.c @@ -4846,6 +4846,43 @@ static int lfs_fs_rawstat(lfs_t *lfs, struct lfs_fsinfo *fsinfo) { return 0; } +int lfs_fs_rawgrow(lfs_t *lfs, lfs_size_t block_count) { + // shrinking is not supported + LFS_ASSERT(block_count >= lfs->block_count); + + if (block_count > lfs->block_count) { + lfs->block_count = block_count; + + // fetch the root + lfs_mdir_t root; + int err = lfs_dir_fetch(lfs, &root, lfs->root); + if (err) { + return err; + } + + // update the superblock + lfs_superblock_t superblock; + lfs_stag_t tag = lfs_dir_get(lfs, &root, LFS_MKTAG(0x7ff, 0x3ff, 0), + LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)), + &superblock); + if (tag < 0) { + return tag; + } + lfs_superblock_fromle32(&superblock); + + superblock.block_count = lfs->block_count; + + lfs_superblock_tole32(&superblock); + err = lfs_dir_commit(lfs, &root, LFS_MKATTRS( + {tag, &superblock})); + if (err) { + return err; + } + } + + return 0; +} + #ifdef LFS_MIGRATE ////// Migration from littelfs v1 below this ////// @@ -6012,6 +6049,22 @@ int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void *, lfs_block_t), void *data) { return err; } +#ifndef LFS_READONLY +int lfs_fs_grow(lfs_t *lfs, lfs_size_t block_count) { + int err = LFS_LOCK(lfs->cfg); + if (err) { + return err; + } + LFS_TRACE("lfs_fs_grow(%p, %"PRIu32")", (void*)lfs, block_count); + + err = lfs_fs_rawgrow(lfs, block_count); + + LFS_TRACE("lfs_fs_grow -> %d", err); + LFS_UNLOCK(lfs->cfg); + return err; +} +#endif + #ifdef LFS_MIGRATE int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) { int err = LFS_LOCK(cfg); diff --git a/lfs.h b/lfs.h index bbe64efe..d9bfe8c0 100644 --- a/lfs.h +++ b/lfs.h @@ -732,6 +732,16 @@ lfs_ssize_t lfs_fs_size(lfs_t *lfs); // Returns a negative error code on failure. int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data); +#ifndef LFS_READONLY +// Grows the filesystem to a new size, updating the superblock with the new +// block count. +// +// Note: This is irreversible. +// +// Returns a negative error code on failure. +int lfs_fs_grow(lfs_t *lfs, lfs_size_t block_count); +#endif + #ifndef LFS_READONLY #ifdef LFS_MIGRATE // Attempts to migrate a previous version of littlefs diff --git a/tests/test_superblocks.toml b/tests/test_superblocks.toml index 67d13f6f..6ff25345 100644 --- a/tests/test_superblocks.toml +++ b/tests/test_superblocks.toml @@ -559,3 +559,108 @@ code = ''' assert(fsinfo.block_count == BLOCK_COUNT); lfs_unmount(&lfs) => 0; ''' + +# mount and grow the filesystem +[cases.test_superblocks_grow] +defines.BLOCK_COUNT = ['ERASE_COUNT/2', 'ERASE_COUNT/4', '2'] +defines.BLOCK_COUNT_2 = 'ERASE_COUNT' +defines.KNOWN_BLOCK_COUNT = [true, false] +code = ''' + lfs_t lfs; + lfs_format(&lfs, cfg) => 0; + + if (KNOWN_BLOCK_COUNT) { + cfg->block_count = BLOCK_COUNT; + } else { + cfg->block_count = 0; + } + + // mount with block_size < erase_size + lfs_mount(&lfs, cfg) => 0; + struct lfs_fsinfo fsinfo; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT); + lfs_unmount(&lfs) => 0; + + // same size is a noop + lfs_mount(&lfs, cfg) => 0; + lfs_fs_grow(&lfs, BLOCK_COUNT) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT); + lfs_unmount(&lfs) => 0; + + lfs_mount(&lfs, cfg) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT); + lfs_unmount(&lfs) => 0; + + // grow to new size + lfs_mount(&lfs, cfg) => 0; + lfs_fs_grow(&lfs, BLOCK_COUNT_2) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT_2); + lfs_unmount(&lfs) => 0; + + if (KNOWN_BLOCK_COUNT) { + cfg->block_count = BLOCK_COUNT_2; + } else { + cfg->block_count = 0; + } + + lfs_mount(&lfs, cfg) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT_2); + lfs_unmount(&lfs) => 0; + + // mounting with the previous size should fail + cfg->block_count = BLOCK_COUNT; + lfs_mount(&lfs, cfg) => LFS_ERR_INVAL; + + if (KNOWN_BLOCK_COUNT) { + cfg->block_count = BLOCK_COUNT_2; + } else { + cfg->block_count = 0; + } + + // same size is a noop + lfs_mount(&lfs, cfg) => 0; + lfs_fs_grow(&lfs, BLOCK_COUNT_2) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT_2); + lfs_unmount(&lfs) => 0; + + lfs_mount(&lfs, cfg) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT_2); + lfs_unmount(&lfs) => 0; + + // do some work + lfs_mount(&lfs, cfg) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT_2); + lfs_file_t file; + lfs_file_open(&lfs, &file, "test", + LFS_O_CREAT | LFS_O_EXCL | LFS_O_WRONLY) => 0; + lfs_file_write(&lfs, &file, "hello!", 6) => 6; + lfs_file_close(&lfs, &file) => 0; + lfs_unmount(&lfs) => 0; + + lfs_mount(&lfs, cfg) => 0; + lfs_fs_stat(&lfs, &fsinfo) => 0; + assert(fsinfo.block_size == BLOCK_SIZE); + assert(fsinfo.block_count == BLOCK_COUNT_2); + lfs_file_open(&lfs, &file, "test", LFS_O_RDONLY) => 0; + uint8_t buffer[256]; + lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => 6; + lfs_file_close(&lfs, &file) => 0; + assert(memcmp(buffer, "hello!", 6) == 0); + lfs_unmount(&lfs) => 0; +'''