Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Grow block count to configured value when LFS_M_GROW mount flag is set #702

Closed
wants to merge 1 commit into from
Closed

Grow block count to configured value when LFS_M_GROW mount flag is set #702

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
84 changes: 80 additions & 4 deletions lfs.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -498,6 +498,7 @@ static int lfs_fs_pred(lfs_t *lfs, const lfs_block_t dir[2],
static lfs_stag_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t dir[2],
lfs_mdir_t *parent);
static int lfs_fs_forceconsistency(lfs_t *lfs);
static int lfs_fs_setblockcount(lfs_t *lfs);
#endif

#ifdef LFS_MIGRATE
Expand Down Expand Up @@ -4104,6 +4105,9 @@ static int lfs_rawmount(lfs_t *lfs, const struct lfs_config *cfg) {
// scan directory blocks for superblock and any global updates
lfs_mdir_t dir = {.tail = {0, 1}};
lfs_block_t cycle = 0;
#ifndef LFS_READONLY
bool grow = false;
#endif
while (!lfs_pair_isnull(dir.tail)) {
if (cycle >= lfs->cfg->block_count/2) {
// loop detected
Expand Down Expand Up @@ -4187,15 +4191,24 @@ static int lfs_rawmount(lfs_t *lfs, const struct lfs_config *cfg) {
}

if (superblock.block_count != lfs->cfg->block_count) {
LFS_ERROR("Invalid block count (%"PRIu32" != %"PRIu32")",
if ((lfs->cfg->flags & LFS_M_GROW)
&& (superblock.block_count < lfs->cfg->block_count)) {
#ifndef LFS_READONLY
LFS_DEBUG("Grow block count from %"PRIu32" to %"PRIu32"",
superblock.block_count, lfs->cfg->block_count);
err = LFS_ERR_INVAL;
goto cleanup;
grow = true;
#endif
} else {
LFS_ERROR("Invalid block count (%"PRIu32" != %"PRIu32")",
superblock.block_count, lfs->cfg->block_count);
err = LFS_ERR_INVAL;
goto cleanup;
}
}

if (superblock.block_size != lfs->cfg->block_size) {
LFS_ERROR("Invalid block size (%"PRIu32" != %"PRIu32")",
superblock.block_count, lfs->cfg->block_count);
superblock.block_size, lfs->cfg->block_size);
err = LFS_ERR_INVAL;
goto cleanup;
}
Expand Down Expand Up @@ -4229,6 +4242,16 @@ static int lfs_rawmount(lfs_t *lfs, const struct lfs_config *cfg) {
lfs->free.off = lfs->seed % lfs->cfg->block_count;
lfs_alloc_drop(lfs);

#ifndef LFS_READONLY
if (grow) {
err = lfs_fs_setblockcount(lfs);
if (err) {
LFS_ERROR("Failed to grow block count");
goto cleanup;
}
}
#endif

return 0;

cleanup:
Expand All @@ -4240,6 +4263,59 @@ static int lfs_rawunmount(lfs_t *lfs) {
return lfs_deinit(lfs);
}

#ifndef LFS_READONLY
static int lfs_fs_setblockcount(lfs_t *lfs) {
// scan directory blocks for superblock
lfs_mdir_t dir = {.tail = {0, 1}};
lfs_block_t cycle = 0;
while (!lfs_pair_isnull(dir.tail)) {
if (cycle >= lfs->cfg->block_count / 2) {
// loop detected
return LFS_ERR_CORRUPT;
}
cycle += 1;

// fetch next block in tail list
lfs_stag_t tag = lfs_dir_fetchmatch(lfs, &dir, dir.tail,
LFS_MKTAG(0x7ff, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8),
NULL,
lfs_dir_find_match, &(struct lfs_dir_find_match){
lfs, "littlefs", 8});
if (tag < 0) {
return tag;
}

// has superblock?
if (tag && !lfs_tag_isdelete(tag)) {
// grab superblock
lfs_superblock_t superblock;
tag = lfs_dir_get(lfs, &dir, LFS_MKTAG(0x7ff, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
&superblock);
if (tag < 0) {
return tag;
}
lfs_superblock_fromle32(&superblock);

// set the new block count
superblock.block_count = lfs->cfg->block_count;

// write back the updated superblock to disk
lfs_superblock_tole32(&superblock);
int err = lfs_dir_commit(lfs, &dir, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
{LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
&superblock}));
if (err) {
return err;
}
return LFS_ERR_OK;
}
}
return LFS_ERR_INVAL;
}
#endif

/// Filesystem filesystem operations ///
int lfs_fs_rawtraverse(lfs_t *lfs,
Expand Down
7 changes: 7 additions & 0 deletions lfs.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -146,6 +146,10 @@ enum lfs_open_flags {
LFS_F_INLINE = 0x100000, // Currently inlined in directory entry
};

enum lfs_mount_flags {
LFS_M_GROW = 0x01, // Grows the filesystem to the configured size
};

// File seek flags
enum lfs_whence_flags {
LFS_SEEK_SET = 0, // Seek relative to an absolute position
Expand Down Expand Up @@ -263,6 +267,9 @@ struct lfs_config {
// can help bound the metadata compaction time. Must be <= block_size.
// Defaults to block_size when zero.
lfs_size_t metadata_max;

// Mount flags, see lfs_mount_flags.
int flags;
};

// File info structure
Expand Down