mirror of
https://gitee.com/openharmony/third_party_littlefs
synced 2024-11-23 06:50:37 +00:00
Combined superblock scan and fetch of xored-globals during mount
Conceptually these are two separate operations. However, they are both only needed during mount, both require iteration over the linked-list of metadata-pairs, and both are independent from each other. Combining these into one gives us a nice code savings. Additionally, this greatly simplifies the lookup of the root directory. Initially we used a flag to indicate which superblock was root, since we didn't want to fetch more pairs than we needed to. But since we're going to fetch all metadata-pairs anyways, we can just use the last superblock we find as the indicator of our root directory.
This commit is contained in:
Christopher Haster
parent
7bacf9b1e0
commit
cf87ba5375
157
lfs.c
157
lfs.c
@ -3116,7 +3116,7 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
|
||||
|
||||
lfs_superblock_tole32(&superblock);
|
||||
err = lfs_dir_commit(lfs, &root,
|
||||
LFS_MKATTR(LFS_TYPE_ROOT, 0, &superblock, sizeof(superblock),
|
||||
LFS_MKATTR(LFS_TYPE_SUPERBLOCK, 0, &superblock, sizeof(superblock),
|
||||
NULL));
|
||||
if (err) {
|
||||
goto cleanup;
|
||||
@ -3139,97 +3139,94 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
|
||||
return err;
|
||||
}
|
||||
|
||||
// find root/superblock
|
||||
lfs_mdir_t root;
|
||||
lfs_superblock_t superblock;
|
||||
lfs_stag_t tag = lfs_dir_findmatch(lfs,
|
||||
&root, (const lfs_block_t[2]){0, 1}, false, 0x7fc00000,
|
||||
LFS_MKTAG(LFS_TYPE_ROOT, 0, 8),
|
||||
lfs_dir_find_match, &(struct lfs_dir_find_match){
|
||||
lfs, "littlefs", 8});
|
||||
if (tag < 0) {
|
||||
err = tag;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
lfs_stag_t res = lfs_dir_get(lfs, &root, 0x7f800000,
|
||||
LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, sizeof(superblock)),
|
||||
&superblock);
|
||||
if (res < 0) {
|
||||
err = res;
|
||||
goto cleanup;
|
||||
}
|
||||
lfs_superblock_fromle32(&superblock);
|
||||
|
||||
lfs->root[0] = root.pair[0];
|
||||
lfs->root[1] = root.pair[1];
|
||||
|
||||
// check version
|
||||
uint16_t major_version = (0xffff & (superblock.version >> 16));
|
||||
uint16_t minor_version = (0xffff & (superblock.version >> 0));
|
||||
if ((major_version != LFS_DISK_VERSION_MAJOR ||
|
||||
minor_version > LFS_DISK_VERSION_MINOR)) {
|
||||
LFS_ERROR("Invalid version %"PRIu32".%"PRIu32,
|
||||
major_version, minor_version);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
// check superblock configuration
|
||||
if (superblock.attr_max) {
|
||||
if (superblock.attr_max > lfs->attr_max) {
|
||||
LFS_ERROR("Unsupported attr_max (%"PRIu32" > %"PRIu32")",
|
||||
superblock.attr_max, lfs->attr_max);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
lfs->attr_max = superblock.attr_max;
|
||||
}
|
||||
|
||||
if (superblock.name_max) {
|
||||
if (superblock.name_max > lfs->name_max) {
|
||||
LFS_ERROR("Unsupported name_max (%"PRIu32" > %"PRIu32")",
|
||||
superblock.name_max, lfs->name_max);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
lfs->name_max = superblock.name_max;
|
||||
}
|
||||
|
||||
if (superblock.inline_max) {
|
||||
if (superblock.inline_max > lfs->inline_max) {
|
||||
LFS_ERROR("Unsupported inline_max (%"PRIu32" > %"PRIu32")",
|
||||
superblock.inline_max, lfs->inline_max);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
lfs->inline_max = superblock.inline_max;
|
||||
}
|
||||
|
||||
// scan for any global updates
|
||||
// scan directory blocks for superblock and any global updates
|
||||
lfs_mdir_t dir = {.tail = {0, 1}};
|
||||
while (!lfs_pair_isnull(dir.tail)) {
|
||||
res = lfs_dir_fetchmatch(lfs, &dir, dir.tail, 0x7c000000,
|
||||
LFS_MKTAG(LFS_TYPE_GLOBALS, 0, 10), NULL, NULL);
|
||||
// fetch next block in tail list
|
||||
lfs_stag_t res = lfs_dir_fetchmatch(lfs, &dir, dir.tail, 0x7fc00000,
|
||||
LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8),
|
||||
lfs_dir_find_match, &(struct lfs_dir_find_match){
|
||||
lfs, "littlefs", 8});
|
||||
if (res < 0) {
|
||||
err = LFS_ERR_INVAL;
|
||||
err = res;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
// has superblock?
|
||||
if (res) {
|
||||
lfs_global_t locals;
|
||||
res = lfs_dir_get(lfs, &dir, 0x7c000000,
|
||||
LFS_MKTAG(LFS_TYPE_GLOBALS, 0, 10), &locals);
|
||||
// update root
|
||||
lfs->root[0] = dir.pair[0];
|
||||
lfs->root[1] = dir.pair[1];
|
||||
|
||||
// grab superblock
|
||||
lfs_superblock_t superblock;
|
||||
res = lfs_dir_get(lfs, &dir, 0x7f800000,
|
||||
LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, sizeof(superblock)),
|
||||
&superblock);
|
||||
if (res < 0) {
|
||||
err = res;
|
||||
goto cleanup;
|
||||
}
|
||||
locals.l.deorphaned = (lfs_tag_type(res) & 1);
|
||||
lfs_superblock_fromle32(&superblock);
|
||||
|
||||
// xor together indirect deletes
|
||||
// check version
|
||||
uint16_t major_version = (0xffff & (superblock.version >> 16));
|
||||
uint16_t minor_version = (0xffff & (superblock.version >> 0));
|
||||
if ((major_version != LFS_DISK_VERSION_MAJOR ||
|
||||
minor_version > LFS_DISK_VERSION_MINOR)) {
|
||||
LFS_ERROR("Invalid version %"PRIu32".%"PRIu32,
|
||||
major_version, minor_version);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
// check superblock configuration
|
||||
if (superblock.attr_max) {
|
||||
if (superblock.attr_max > lfs->attr_max) {
|
||||
LFS_ERROR("Unsupported attr_max (%"PRIu32" > %"PRIu32")",
|
||||
superblock.attr_max, lfs->attr_max);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
lfs->attr_max = superblock.attr_max;
|
||||
}
|
||||
|
||||
if (superblock.name_max) {
|
||||
if (superblock.name_max > lfs->name_max) {
|
||||
LFS_ERROR("Unsupported name_max (%"PRIu32" > %"PRIu32")",
|
||||
superblock.name_max, lfs->name_max);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
lfs->name_max = superblock.name_max;
|
||||
}
|
||||
|
||||
if (superblock.inline_max) {
|
||||
if (superblock.inline_max > lfs->inline_max) {
|
||||
LFS_ERROR("Unsupported inline_max (%"PRIu32" > %"PRIu32")",
|
||||
superblock.inline_max, lfs->inline_max);
|
||||
err = LFS_ERR_INVAL;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
lfs->inline_max = superblock.inline_max;
|
||||
}
|
||||
}
|
||||
|
||||
// has globals?
|
||||
lfs_global_t locals;
|
||||
res = lfs_dir_get(lfs, &dir, 0x7c000000,
|
||||
LFS_MKTAG(LFS_TYPE_GLOBALS, 0, 10), &locals);
|
||||
if (res < 0 && res != LFS_ERR_NOENT) {
|
||||
err = res;
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
if (res != LFS_ERR_NOENT) {
|
||||
locals.l.deorphaned = (lfs_tag_type(res) & 1);
|
||||
// xor together to find resulting globals
|
||||
lfs_global_xor(&lfs->locals, &locals);
|
||||
}
|
||||
}
|
||||
|
||||
8
lfs.h
8
lfs.h
@ -94,27 +94,25 @@ enum lfs_type {
|
||||
|
||||
// internally used types
|
||||
LFS_TYPE_USER = 0x100,
|
||||
LFS_TYPE_SUPERBLOCK = 0x001,
|
||||
LFS_TYPE_ROOT = 0x000,
|
||||
LFS_TYPE_NAME = 0x000,
|
||||
LFS_TYPE_DELETE = 0x020,
|
||||
LFS_TYPE_STRUCT = 0x040,
|
||||
LFS_TYPE_GLOBALS = 0x0e0,
|
||||
LFS_TYPE_TAIL = 0x080,
|
||||
LFS_TYPE_SOFTTAIL = 0x080,
|
||||
LFS_TYPE_HARDTAIL = 0x081,
|
||||
LFS_TYPE_CRC = 0x0a0,
|
||||
LFS_TYPE_SUPERBLOCK = 0x001,
|
||||
LFS_TYPE_GLOBALS = 0x0e0,
|
||||
|
||||
LFS_TYPE_DIRSTRUCT = 0x040,
|
||||
LFS_TYPE_INLINESTRUCT = 0x041,
|
||||
LFS_TYPE_CTZSTRUCT = 0x042,
|
||||
|
||||
// internal chip sources
|
||||
LFS_FROM_REGION = 0x000,
|
||||
LFS_FROM_MEM = 0x000,
|
||||
LFS_FROM_DISK = 0x200,
|
||||
LFS_FROM_MOVE = 0x0c1,
|
||||
LFS_FROM_USERATTRS = 0x0c2,
|
||||
LFS_FROM_SUPERBLOCK = 0x0c3,
|
||||
};
|
||||
|
||||
// File open flags
|
||||
|
||||
@ -7,7 +7,6 @@ TYPES = {
|
||||
(0x1ff, 0x002): 'reg',
|
||||
(0x1ff, 0x003): 'dir',
|
||||
(0x1ff, 0x001): 'superblock',
|
||||
(0x1ff, 0x000): 'root',
|
||||
(0x1ff, 0x020): 'delete',
|
||||
(0x1f0, 0x0e0): 'globals',
|
||||
(0x1ff, 0x080): 'tail soft',
|
||||
|
||||
Loading…
Reference in New Issue
Block a user