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Fixed issues with neighbor updates during moves

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The root of the problem was some assumptions about what tags could be
sent to lfs_dir_commit.

- The first assumption is that there could be only one splice (create/delete)
  tag at a time, which is trivially broken by the core commit in lfs_rename.

- The second assumption is that there is at most one create and one delete in
  a single commit. This is less obvious but turns out to not be true in
  the case that we rename a file such that it overwrites another file in
  the same directory (1 delete for source file, 1 delete for destination).

- The third assumption was that there was an ordering to the
  delete/creates passed to lfs_dir_commit. It may be possible to force all
  deletes to follow creates by rearranging the tags in lfs_rename, but
  this risks overflowing tag ids.

The way the lfs_dir_commit first collected the "deletetag" and "createtag"
broke all three of these assumptions. And because we lose the ordering
information we can no longer apply the directory changes to open files
correctly. The file ids may be shifted in a way that doesn't reflect the
actual operations on disk.

These problems were made worst by lfs_dir_commit cleaning up moves
implicitly, which also creates deletes implicitly. While cleaning up moves
in lfs_dir_commit may save some code size, it makes the commit logic much more
difficult to implement correctly.

This bug turned into pulling out a dead tree stump, roots and all.

I ended up reworking how lfs_dir_commit updates open files so that it
has less assumptions, now it just traverses the commit tags multiple
times in order to update file ids after a successful commit in the
correct order.

This also got rid of the dir copy by carefully updating split dirs
after all files have an up-to-date copy of the original dir.

I also just removed the implicit move cleanup. It turns out the only
commits that can occur before we have cleaned up the move is in
lfs_fs_relocate, so it was simple enough to explicitly handle this case
when we update our parent and pred during a relocate.

Cases where we may need to fix moves:
- In lfs_rename when we move a file/dir
- In lfs_demove if we lose power
- In lfs_fs_relocate if we have to relocate our parent and we find it
  had a pending move (or else the move will be outdated)
- In lfs_fs_relocate if we have to relocate our predecessor and we find it
  had a pending move (or else the move will be outdated)

Note the two cases in lfs_fs_relocate may be recursive. But
lfs_fs_relocate can only trigger other lfs_fs_relocates so it's not
possible for pending moves to spill out into other filesystem commits

And of couse, I added several tests to cover these situations. Hopefully
the rename-with-open-files logic should be fairly locked down now.

found with initial fix by eastmoutain
This commit is contained in:
Christopher Haster
2020-01-20 17:35:45 -06:00
parent 9453ebd15d
commit f4b6a6b328
4 changed files with 1003 additions and 117 deletions
Download Patch File Download Diff File Expand all files Collapse all files

225
lfs.c
View File

@@ -265,6 +265,12 @@ typedef int32_t lfs_stag_t;
#define LFS_MKTAG(type, id, size) \
(((lfs_tag_t)(type) << 20) | ((lfs_tag_t)(id) << 10) | (lfs_tag_t)(size))
#define LFS_MKTAG_IF(cond, type, id, size) \
((cond) ? LFS_MKTAG(type, id, size) : LFS_MKTAG(LFS_FROM_NOOP, 0, 0))
#define LFS_MKTAG_IF_ELSE(cond, type1, id1, size1, type2, id2, size2) \
((cond) ? LFS_MKTAG(type, id, size) : LFS_MKTAG(type2, id2, size2))
static inline bool lfs_tag_isvalid(lfs_tag_t tag) {
return !(tag & 0x80000000);
}
@@ -652,7 +658,7 @@ static int lfs_dir_traverse_filter(void *p,
static int lfs_dir_traverse(lfs_t *lfs,
const lfs_mdir_t *dir, lfs_off_t off, lfs_tag_t ptag,
const struct lfs_mattr *attrs, int attrcount, bool hasseenmove,
const struct lfs_mattr *attrs, int attrcount,
lfs_tag_t tmask, lfs_tag_t ttag,
uint16_t begin, uint16_t end, int16_t diff,
int (*cb)(void *data, lfs_tag_t tag, const void *buffer), void *data) {
@@ -680,13 +686,6 @@ static int lfs_dir_traverse(lfs_t *lfs,
buffer = attrs[0].buffer;
attrs += 1;
attrcount -= 1;
} else if (!hasseenmove &&
lfs_gstate_hasmovehere(&lfs->gpending, dir->pair)) {
// Wait, we have pending move? Handle this here (we need to
// or else we risk letting moves fall out of date)
tag = lfs->gpending.tag & LFS_MKTAG(0x7ff, 0x3ff, 0);
buffer = NULL;
hasseenmove = true;
} else {
return 0;
}
@@ -701,7 +700,7 @@ static int lfs_dir_traverse(lfs_t *lfs,
if (lfs_tag_id(tmask) != 0) {
// scan for duplicates and update tag based on creates/deletes
int filter = lfs_dir_traverse(lfs,
dir, off, ptag, attrs, attrcount, hasseenmove,
dir, off, ptag, attrs, attrcount,
0, 0, 0, 0, 0,
lfs_dir_traverse_filter, &tag);
if (filter < 0) {
@@ -725,7 +724,7 @@ static int lfs_dir_traverse(lfs_t *lfs,
uint16_t fromid = lfs_tag_size(tag);
uint16_t toid = lfs_tag_id(tag);
int err = lfs_dir_traverse(lfs,
buffer, 0, LFS_BLOCK_NULL, NULL, 0, true,
buffer, 0, LFS_BLOCK_NULL, NULL, 0,
LFS_MKTAG(0x600, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_STRUCT, 0, 0),
fromid, fromid+1, toid-fromid+diff,
@@ -1443,7 +1442,7 @@ static int lfs_dir_compact(lfs_t *lfs,
// find size
lfs_size_t size = 0;
int err = lfs_dir_traverse(lfs,
source, 0, LFS_BLOCK_NULL, attrs, attrcount, false,
source, 0, LFS_BLOCK_NULL, attrs, attrcount,
LFS_MKTAG(0x400, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_NAME, 0, 0),
begin, end, -begin,
@@ -1569,7 +1568,7 @@ static int lfs_dir_compact(lfs_t *lfs,
// traverse the directory, this time writing out all unique tags
err = lfs_dir_traverse(lfs,
source, 0, LFS_BLOCK_NULL, attrs, attrcount, false,
source, 0, LFS_BLOCK_NULL, attrs, attrcount,
LFS_MKTAG(0x400, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_NAME, 0, 0),
begin, end, -begin,
@@ -1627,11 +1626,6 @@ static int lfs_dir_compact(lfs_t *lfs,
dir->count = end - begin;
dir->off = commit.off;
dir->etag = commit.ptag;
// note we able to have already handled move here
if (lfs_gstate_hasmovehere(&lfs->gpending, dir->pair)) {
lfs_gstate_xormove(&lfs->gpending,
&lfs->gpending, 0x3ff, NULL);
}
}
break;
@@ -1696,16 +1690,14 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
}
// calculate changes to the directory
lfs_tag_t deletetag = LFS_BLOCK_NULL;
lfs_tag_t createtag = LFS_BLOCK_NULL;
bool hasdelete = false;
for (int i = 0; i < attrcount; i++) {
if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_CREATE) {
createtag = attrs[i].tag;
dir->count += 1;
} else if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_DELETE) {
deletetag = attrs[i].tag;
LFS_ASSERT(dir->count > 0);
dir->count -= 1;
hasdelete = true;
} else if (lfs_tag_type1(attrs[i].tag) == LFS_TYPE_TAIL) {
dir->tail[0] = ((lfs_block_t*)attrs[i].buffer)[0];
dir->tail[1] = ((lfs_block_t*)attrs[i].buffer)[1];
@@ -1714,18 +1706,8 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
}
}
// do we have a pending move?
if (lfs_gstate_hasmovehere(&lfs->gpending, dir->pair)) {
deletetag = lfs->gpending.tag & LFS_MKTAG(0x7ff, 0x3ff, 0);
LFS_ASSERT(dir->count > 0);
dir->count -= 1;
// mark gdelta so we reflect the move we will fix
lfs_gstate_xormove(&lfs->gdelta, &lfs->gpending, 0x3ff, NULL);
}
// should we actually drop the directory block?
if (lfs_tag_isvalid(deletetag) && dir->count == 0) {
if (hasdelete && dir->count == 0) {
lfs_mdir_t pdir;
int err = lfs_fs_pred(lfs, dir->pair, &pdir);
if (err && err != LFS_ERR_NOENT) {
@@ -1752,7 +1734,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
// traverse attrs that need to be written out
lfs_pair_tole32(dir->tail);
int err = lfs_dir_traverse(lfs,
dir, dir->off, dir->etag, attrs, attrcount, false,
dir, dir->off, dir->etag, attrs, attrcount,
0, 0, 0, 0, 0,
lfs_dir_commit_commit, &(struct lfs_dir_commit_commit){
lfs, &commit});
@@ -1797,13 +1779,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
LFS_ASSERT(commit.off % lfs->cfg->prog_size == 0);
dir->off = commit.off;
dir->etag = commit.ptag;
// note we able to have already handled move here
if (lfs_gstate_hasmovehere(&lfs->gpending, dir->pair)) {
lfs_gstate_xormove(&lfs->gpending, &lfs->gpending, 0x3ff, NULL);
}
// update gstate
// and update gstate
lfs->gstate = lfs->gpending;
lfs->gdelta = (struct lfs_gstate){0};
} else {
@@ -1818,29 +1794,42 @@ compact:
}
}
// update any directories that are affected
lfs_mdir_t copy = *dir;
// two passes, once for things that aren't us, and one
// for things that are
// this complicated bit of logic is for fixing up any active
// metadata-pairs that we may have affected
//
// note we have to make two passes since the mdir passed to
// lfs_dir_commit could also be in this list, and even then
// we need to copy the pair so they don't get clobbered if we refetch
// our mdir.
for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
if (lfs_pair_cmp(d->m.pair, copy.pair) == 0) {
d->m = copy;
if (d->id == lfs_tag_id(deletetag)) {
d->m.pair[0] = LFS_BLOCK_NULL;
d->m.pair[1] = LFS_BLOCK_NULL;
} else if (d->id > lfs_tag_id(deletetag)) {
d->id -= 1;
if (d->type == LFS_TYPE_DIR) {
((lfs_dir_t*)d)->pos -= 1;
}
} else if (&d->m != dir && d->id >= lfs_tag_id(createtag)) {
d->id += 1;
if (d->type == LFS_TYPE_DIR) {
((lfs_dir_t*)d)->pos += 1;
if (&d->m != dir && lfs_pair_cmp(d->m.pair, dir->pair) == 0) {
d->m = *dir;
for (int i = 0; i < attrcount; i++) {
if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_DELETE &&
d->id == lfs_tag_id(attrs[i].tag)) {
d->m.pair[0] = LFS_BLOCK_NULL;
d->m.pair[1] = LFS_BLOCK_NULL;
} else if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_DELETE &&
d->id > lfs_tag_id(attrs[i].tag)) {
d->id -= 1;
if (d->type == LFS_TYPE_DIR) {
((lfs_dir_t*)d)->pos -= 1;
}
} else if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_CREATE &&
d->id >= lfs_tag_id(attrs[i].tag)) {
d->id += 1;
if (d->type == LFS_TYPE_DIR) {
((lfs_dir_t*)d)->pos += 1;
}
}
}
}
}
lfs_block_t pair[2] = {dir->pair[0], dir->pair[1]};
for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
if (lfs_pair_cmp(d->m.pair, pair) == 0) {
while (d->id >= d->m.count && d->m.split) {
// we split and id is on tail now
d->id -= d->m.count;
@@ -1931,9 +1920,8 @@ int lfs_mkdir(lfs_t *lfs, const char *path) {
{LFS_MKTAG(LFS_TYPE_CREATE, id, 0), NULL},
{LFS_MKTAG(LFS_TYPE_DIR, id, nlen), path},
{LFS_MKTAG(LFS_TYPE_DIRSTRUCT, id, 8), dir.pair},
{!cwd.split
? LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8)
: LFS_MKTAG(LFS_FROM_NOOP, 0, 0), dir.pair}));
{LFS_MKTAG_IF(!cwd.split,
LFS_TYPE_SOFTTAIL, 0x3ff, 8), dir.pair}));
lfs_pair_fromle32(dir.pair);
if (err) {
LFS_TRACE("lfs_mkdir -> %d", err);
@@ -2375,9 +2363,9 @@ int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
// get next slot and create entry to remember name
err = lfs_dir_commit(lfs, &file->m, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_CREATE, file->id, 0), NULL},
{LFS_MKTAG(LFS_TYPE_CREATE, file->id, 0)},
{LFS_MKTAG(LFS_TYPE_REG, file->id, nlen), path},
{LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0), NULL}));
{LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0)}));
if (err) {
err = LFS_ERR_NAMETOOLONG;
goto cleanup;
@@ -3145,7 +3133,7 @@ int lfs_remove(lfs_t *lfs, const char *path) {
// delete the entry
err = lfs_dir_commit(lfs, &cwd, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(tag), 0), NULL}));
{LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(tag), 0)}));
if (err) {
LFS_TRACE("lfs_remove -> %d", err);
return err;
@@ -3186,7 +3174,8 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
lfs_mdir_t oldcwd;
lfs_stag_t oldtag = lfs_dir_find(lfs, &oldcwd, &oldpath, NULL);
if (oldtag < 0 || lfs_tag_id(oldtag) == 0x3ff) {
LFS_TRACE("lfs_rename -> %"PRId32, (oldtag < 0) ? oldtag : LFS_ERR_INVAL);
LFS_TRACE("lfs_rename -> %"PRId32,
(oldtag < 0) ? oldtag : LFS_ERR_INVAL);
return (oldtag < 0) ? (int)oldtag : LFS_ERR_INVAL;
}
@@ -3196,7 +3185,8 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
lfs_stag_t prevtag = lfs_dir_find(lfs, &newcwd, &newpath, &newid);
if ((prevtag < 0 || lfs_tag_id(prevtag) == 0x3ff) &&
!(prevtag == LFS_ERR_NOENT && newid != 0x3ff)) {
LFS_TRACE("lfs_rename -> %"PRId32, (prevtag < 0) ? prevtag : LFS_ERR_INVAL);
LFS_TRACE("lfs_rename -> %"PRId32,
(prevtag < 0) ? prevtag : LFS_ERR_INVAL);
return (prevtag < 0) ? (int)prevtag : LFS_ERR_INVAL;
}
@@ -3239,26 +3229,28 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
}
// create move to fix later
bool samepair = (lfs_pair_cmp(oldcwd.pair, newcwd.pair) == 0);
uint16_t newoldtagid = lfs_tag_id(oldtag);
if (lfs_pair_cmp(oldcwd.pair, newcwd.pair) == 0 &&
prevtag == LFS_ERR_NOENT && newid <= newoldtagid) {
// there is a small chance we are being renamed in the same directory
// to an id less than our old id, the global update to handle this
// is a bit messy
newoldtagid += 1;
if (samepair) {
// there is a small chance we are being renamed in the same
// directory/ to an id less than our old id, the global update
// to handle this is a bit messy
if (prevtag == LFS_ERR_NOENT && newid <= newoldtagid) {
newoldtagid += 1;
}
} else {
lfs_fs_prepmove(lfs, newoldtagid, oldcwd.pair);
}
lfs_fs_prepmove(lfs, newoldtagid, oldcwd.pair);
// move over all attributes
err = lfs_dir_commit(lfs, &newcwd, LFS_MKATTRS(
{prevtag != LFS_ERR_NOENT
? LFS_MKTAG(LFS_TYPE_DELETE, newid, 0)
: LFS_MKTAG(LFS_FROM_NOOP, 0, 0), NULL},
{LFS_MKTAG(LFS_TYPE_CREATE, newid, 0), NULL},
{LFS_MKTAG(lfs_tag_type3(oldtag), newid, strlen(newpath)),
newpath},
{LFS_MKTAG(LFS_FROM_MOVE, newid, lfs_tag_id(oldtag)), &oldcwd}));
{LFS_MKTAG_IF(prevtag != LFS_ERR_NOENT,
LFS_TYPE_DELETE, newid, 0)},
{LFS_MKTAG(LFS_TYPE_CREATE, newid, 0)},
{LFS_MKTAG(lfs_tag_type3(oldtag), newid, strlen(newpath)), newpath},
{LFS_MKTAG(LFS_FROM_MOVE, newid, lfs_tag_id(oldtag)), &oldcwd},
{LFS_MKTAG_IF(samepair,
LFS_TYPE_DELETE, newoldtagid, 0)}));
if (err) {
LFS_TRACE("lfs_rename -> %d", err);
return err;
@@ -3266,8 +3258,11 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
// let commit clean up after move (if we're different! otherwise move
// logic already fixed it for us)
if (lfs_pair_cmp(oldcwd.pair, newcwd.pair) != 0) {
err = lfs_dir_commit(lfs, &oldcwd, NULL, 0);
if (!samepair && lfs_gstate_hasmove(&lfs->gstate)) {
// prep gstate and delete move id
lfs_fs_prepmove(lfs, 0x3ff, NULL);
err = lfs_dir_commit(lfs, &oldcwd, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(oldtag), 0)}));
if (err) {
LFS_TRACE("lfs_rename -> %d", err);
return err;
@@ -3557,7 +3552,7 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
lfs_superblock_tole32(&superblock);
err = lfs_dir_commit(lfs, &root, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_CREATE, 0, 0), NULL},
{LFS_MKTAG(LFS_TYPE_CREATE, 0, 0)},
{LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
{LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
&superblock}));
@@ -3922,8 +3917,25 @@ static int lfs_fs_relocate(lfs_t *lfs,
// update disk, this creates a desync
lfs_fs_preporphans(lfs, +1);
// fix pending move in this pair? this looks like an optimization but
// is in fact _required_ since relocating may outdate the move.
uint16_t moveid = 0x3ff;
if (lfs_gstate_hasmovehere(&lfs->gpending, parent.pair)) {
moveid = lfs_tag_id(lfs->gpending.tag);
LFS_DEBUG("Fixing move while relocating "
"%"PRIx32" %"PRIx32" %"PRIx16"\n",
parent.pair[0], parent.pair[1], moveid);
lfs_fs_prepmove(lfs, 0x3ff, NULL);
if (moveid < lfs_tag_id(tag)) {
tag -= LFS_MKTAG(0, 1, 0);
}
}
lfs_pair_tole32(newpair);
int err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS({tag, newpair}));
int err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS(
{LFS_MKTAG_IF(moveid != 0x3ff,
LFS_TYPE_DELETE, moveid, 0)},
{tag, newpair}));
lfs_pair_fromle32(newpair);
if (err) {
return err;
@@ -3941,9 +3953,22 @@ static int lfs_fs_relocate(lfs_t *lfs,
// if we can't find dir, it must be new
if (err != LFS_ERR_NOENT) {
// fix pending move in this pair? this looks like an optimization but
// is in fact _required_ since relocating may outdate the move.
uint16_t moveid = 0x3ff;
if (lfs_gstate_hasmovehere(&lfs->gpending, parent.pair)) {
moveid = lfs_tag_id(lfs->gpending.tag);
LFS_DEBUG("Fixing move while relocating "
"%"PRIx32" %"PRIx32" %"PRIx16"\n",
parent.pair[0], parent.pair[1], moveid);
lfs_fs_prepmove(lfs, 0x3ff, NULL);
}
// replace bad pair, either we clean up desync, or no desync occured
lfs_pair_tole32(newpair);
err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS(
{LFS_MKTAG_IF(moveid != 0x3ff,
LFS_TYPE_DELETE, moveid, 0)},
{LFS_MKTAG(LFS_TYPE_TAIL + parent.split, 0x3ff, 8), newpair}));
lfs_pair_fromle32(newpair);
if (err) {
@@ -3987,8 +4012,11 @@ static int lfs_fs_demove(lfs_t *lfs) {
return err;
}
// rely on cancel logic inside commit
err = lfs_dir_commit(lfs, &movedir, NULL, 0);
// prep gstate and delete move id
uint16_t moveid = lfs_tag_id(lfs->gstate.tag);
lfs_fs_prepmove(lfs, 0x3ff, NULL);
err = lfs_dir_commit(lfs, &movedir, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_DELETE, moveid, 0)}));
if (err) {
return err;
}
@@ -4630,13 +4658,15 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
lfs1_entry_tole32(&entry1.d);
err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_CREATE, id, 0), NULL},
{LFS_MKTAG(
isdir ? LFS_TYPE_DIR : LFS_TYPE_REG,
id, entry1.d.nlen), name},
{LFS_MKTAG(
isdir ? LFS_TYPE_DIRSTRUCT : LFS_TYPE_CTZSTRUCT,
id, sizeof(entry1.d.u)), &entry1.d.u}));
{LFS_MKTAG(LFS_TYPE_CREATE, id, 0)},
{LFS_MKTAG_IF_ELSE(isdir,
LFS_TYPE_DIR, id, entry1.d.nlen,
LFS_TYPE_REG, id, entry1.d.nlen),
name},
{LFS_MKTAG_IF_ELSE(isdir,
LFS_TYPE_DIRSTRUCT, id, sizeof(entry1.d.u),
LFS_TYPE_CTZSTRUCT, id, sizeof(entry1.d.u)),
&entry1.d.u}));
lfs1_entry_fromle32(&entry1.d);
if (err) {
goto cleanup;
@@ -4659,8 +4689,7 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
lfs_pair_tole32(dir2.pair);
err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8),
dir1.d.tail}));
{LFS_MKTAG(LFS_TYPE_SOFTTAIL, 0x3ff, 8), dir1.d.tail}));
lfs_pair_fromle32(dir2.pair);
if (err) {
goto cleanup;
@@ -4733,7 +4762,7 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
lfs_superblock_tole32(&superblock);
err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
{LFS_MKTAG(LFS_TYPE_CREATE, 0, 0), NULL},
{LFS_MKTAG(LFS_TYPE_CREATE, 0, 0)},
{LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
{LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
&superblock}));

34
scripts/readmdir.py
View File

@@ -106,6 +106,13 @@ class Tag:
0x3ff if self.isattr else 0,
0)
def chid(self, nid):
ntag = Tag(self.type, nid, self.size)
if hasattr(self, 'off'): ntag.off = self.off
if hasattr(self, 'data'): ntag.data = self.data
if hasattr(self, 'crc'): ntag.crc = self.crc
return ntag
def typerepr(self):
if self.is_('crc') and getattr(self, 'crc', 0xffffffff) != 0xffffffff:
return 'crc (bad)'
@@ -197,22 +204,29 @@ class MetadataPair:
crc = 0
tag = Tag(int(tag) ^ ((tag.type & 1) << 31))
# find active ids
self.ids = list(it.takewhile(
lambda id: Tag('name', id, 0) in self,
it.count()))
# find most recent tags
self.tags = []
for tag in self.log:
if tag.is_('crc') or tag.is_('splice'):
continue
if tag in self and self[tag] is tag:
self.tags.append(tag)
elif tag.id == 0x3ff:
if tag in self and self[tag] is tag:
self.tags.append(tag)
else:
# id could have change, I know this is messy and slow
# but it works
for id in self.ids:
ntag = tag.chid(id)
if ntag in self and self[ntag] is tag:
self.tags.append(ntag)
self.tags = sorted(self.tags)
# and ids
self.ids = list(it.takewhile(
lambda id: Tag('name', id, 0) in self,
it.count()))
def __bool__(self):
return bool(self.log)
@@ -247,8 +261,8 @@ class MetadataPair:
gdiff += tag.schunk
if (int(gmask) & int(tag)) == (int(gmask) & int(
Tag(gtag.type, gtag.id - gdiff, gtag.size))):
if ((int(gmask) & int(tag)) ==
(int(gmask) & int(gtag.chid(gtag.id - gdiff)))):
if tag.size == 0x3ff:
# deleted
break

19
scripts/readtree.py
View File

@@ -38,6 +38,8 @@ def dumptags(args, mdir, f):
'<II', tag.data[:8].ljust(8, b'\xff')))
if tag.is_('inlinestruct'):
f.write(" inline size %d" % tag.size)
if tag.is_('gstate'):
f.write(" 0x%s" % ''.join('%02x' % c for c in tag.data))
if tag.is_('tail'):
f.write(" tail {%#x, %#x}" % struct.unpack(
'<II', tag.data[:8].ljust(8, b'\xff')))
@@ -56,7 +58,7 @@ def dumpentries(args, mdir, f):
struct_ = mdir[Tag('struct', id_, 0)]
f.write("id %d %s %s" % (
name.id, name.typerepr(),
id_, name.typerepr(),
json.dumps(name.data.decode('utf8'))))
if struct_.is_('dirstruct'):
f.write(" dir {%#x, %#x}" % struct.unpack(
@@ -177,11 +179,14 @@ def main(args):
for mdir in dir:
for tag in mdir.tags:
if tag.is_('dir'):
npath = tag.data.decode('utf8')
dirstruct = mdir[Tag('dirstruct', tag.id, 0)]
nblocks = struct.unpack('<II', dirstruct.data)
nmdir = dirtable[tuple(sorted(nblocks))]
pending.append(((path + '/' + npath), nmdir))
try:
npath = tag.data.decode('utf8')
dirstruct = mdir[Tag('dirstruct', tag.id, 0)]
nblocks = struct.unpack('<II', dirstruct.data)
nmdir = dirtable[tuple(sorted(nblocks))]
pending.append(((path + '/' + npath), nmdir))
except KeyError:
pass
dir[0].path = path.replace('//', '/')
@@ -209,7 +214,7 @@ def main(args):
blocks = struct.unpack('<II', gstate[4:4+8].ljust(8, b'\xff'))
if tag.size:
print(" orphans %d" % tag.size)
if not tag.isvalid:
if tag.type:
print(" move dir {%#x, %#x} id %d" % (
blocks[0], blocks[1], tag.id))

842
tests_/test_move.toml
View File

@@ -349,7 +349,7 @@ code = '''
assert(strcmp(info.name, "hello") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 5+8+6);
count += 1;
count += 1;
}
if (lfs_stat(&lfs, "c/hello", &info) == 0) {
assert(strcmp(info.name, "hello") == 0);
@@ -375,6 +375,7 @@ code = '''
lfs_rename(&lfs, "c/hello", "d/hello") => 0;
} else if (lfs_stat(&lfs, "d/hello", &info) == 0) {
// success
lfs_unmount(&lfs) => 0;
break;
} else {
// create file
@@ -807,7 +808,7 @@ code = '''
if (lfs_stat(&lfs, "b/hi", &info) == 0) {
assert(strcmp(info.name, "hi") == 0);
assert(info.type == LFS_TYPE_DIR);
count += 1;
count += 1;
}
if (lfs_stat(&lfs, "c/hi", &info) == 0) {
assert(strcmp(info.name, "hi") == 0);
@@ -830,6 +831,7 @@ code = '''
} else if (lfs_stat(&lfs, "c/hi", &info) == 0) {
lfs_rename(&lfs, "c/hi", "d/hi") => 0;
} else if (lfs_stat(&lfs, "d/hi", &info) == 0) {
lfs_unmount(&lfs) => 0;
break; // success
} else {
// create dir and rename for atomicity
@@ -955,3 +957,839 @@ code = '''
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;
'''
# Other specific corner cases
[[case]] # create + delete in same commit with neighbors
code = '''
lfs_format(&lfs, &cfg) => 0;
lfs_mount(&lfs, &cfg) => 0;
// littlefs keeps files sorted, so we know the order these will be in
lfs_file_open(&lfs, &file, "/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.1", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/2.in_between",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.2", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/4.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.3", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_t files[3];
lfs_file_open(&lfs, &files[0], "0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "2.in_between",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "4.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.4", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.5", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.6", 7) => 7;
// rename file while everything is open, this triggers both
// a create and delete simultaneously
lfs_rename(&lfs, "/1.move_me", "/3.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
// check that nothing was corrupted
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.in_between") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "3.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 0);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "4.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.4") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/2.in_between", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.5") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/4.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.6") == 0);
lfs_file_close(&lfs, &file) => 0;
// now move back
lfs_file_open(&lfs, &files[0], "0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "2.in_between",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "4.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.7", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.8", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.9", 7) => 7;
// rename file while everything is open, this triggers both
// a create and delete simultaneously
lfs_rename(&lfs, "/3.move_me", "/1.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
// and check that nothing was corrupted again
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "1.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 0);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.in_between") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "4.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.7") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/2.in_between", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.8") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/4.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.9") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;
'''
# Other specific corner cases
[[case]] # create + delete + delete in same commit with neighbors
code = '''
lfs_format(&lfs, &cfg) => 0;
lfs_mount(&lfs, &cfg) => 0;
// littlefs keeps files sorted, so we know the order these will be in
lfs_file_open(&lfs, &file, "/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/3.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "remove me",
sizeof("remove me")) => sizeof("remove me");
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.1", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/2.in_between",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.2", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/4.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.3", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_t files[3];
lfs_file_open(&lfs, &files[0], "0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "2.in_between",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "4.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.4", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.5", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.6", 7) => 7;
// rename file while everything is open, this triggers both
// a create and delete simultaneously
lfs_rename(&lfs, "/1.move_me", "/3.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
// check that nothing was corrupted
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.in_between") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "3.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 0);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "4.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.4") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/2.in_between", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.5") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/4.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.6") == 0);
lfs_file_close(&lfs, &file) => 0;
// now move back
lfs_file_open(&lfs, &file, "/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "remove me",
sizeof("remove me")) => sizeof("remove me");
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &files[0], "0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "2.in_between",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "4.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.7", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.8", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.9", 7) => 7;
// rename file while everything is open, this triggers both
// a create and delete simultaneously
lfs_rename(&lfs, "/3.move_me", "/1.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
// and check that nothing was corrupted again
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "1.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 0);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.in_between") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "4.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.7") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/2.in_between", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.8") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/4.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.9") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;
'''
[[case]] # create + delete in different dirs with neighbors
code = '''
lfs_format(&lfs, &cfg) => 0;
lfs_mount(&lfs, &cfg) => 0;
// littlefs keeps files sorted, so we know the order these will be in
lfs_mkdir(&lfs, "/dir.1") => 0;
lfs_mkdir(&lfs, "/dir.2") => 0;
lfs_file_open(&lfs, &file, "/dir.1/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.2/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "remove me",
sizeof("remove me")) => sizeof("remove me");
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.1/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.1", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.1/2.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.2", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.2/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.3", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.2/2.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.4", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_t files[4];
lfs_file_open(&lfs, &files[0], "/dir.1/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "/dir.1/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "/dir.2/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[3], "/dir.2/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.5", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.6", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.7", 7) => 7;
lfs_file_write(&lfs, &files[3], "test.8", 7) => 7;
// rename file while everything is open, this triggers both
// a create and delete as it overwrites the destination file
lfs_rename(&lfs, "/dir.1/1.move_me", "/dir.2/1.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
lfs_file_close(&lfs, &files[3]) => 0;
// check that nothing was corrupted
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "dir.1") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "dir.2") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_dir_open(&lfs, &dir, "/dir.1") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_dir_open(&lfs, &dir, "/dir.2") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "1.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 0);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/dir.1/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.5") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.1/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.6") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.2/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.7") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.2/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.8") == 0);
lfs_file_close(&lfs, &file) => 0;
// now move back
lfs_file_open(&lfs, &file, "/dir.1/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "remove me",
sizeof("remove me")) => sizeof("remove me");
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &files[0], "/dir.1/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "/dir.1/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "/dir.2/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[3], "/dir.2/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.9", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.a", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.b", 7) => 7;
lfs_file_write(&lfs, &files[3], "test.c", 7) => 7;
// rename file while everything is open, this triggers both
// a create and delete simultaneously
lfs_rename(&lfs, "/dir.2/1.move_me", "/dir.1/1.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
lfs_file_close(&lfs, &files[3]) => 0;
// and check that nothing was corrupted again
lfs_dir_open(&lfs, &dir, "/") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "dir.1") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "dir.2") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_dir_open(&lfs, &dir, "/dir.1") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "1.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 0);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_dir_open(&lfs, &dir, "/dir.2") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/dir.1/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.9") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.1/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.a") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.2/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.b") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/dir.2/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.c") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;
'''
[[case]] # move fix in relocation
in = "lfs.c"
define.RELOCATIONS = 'range(0x3+1)'
define.LFS_ERASE_CYCLES = 0xffffffff
code = '''
lfs_format(&lfs, &cfg) => 0;
lfs_mount(&lfs, &cfg) => 0;
lfs_mkdir(&lfs, "/parent") => 0;
lfs_mkdir(&lfs, "/parent/child") => 0;
lfs_file_open(&lfs, &file, "/parent/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "move me",
sizeof("move me")) => sizeof("move me");
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.1", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/2.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.2", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.3", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/2.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.4", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_t files[4];
lfs_file_open(&lfs, &files[0], "/parent/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "/parent/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "/parent/child/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[3], "/parent/child/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.5", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.6", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.7", 7) => 7;
lfs_file_write(&lfs, &files[3], "test.8", 7) => 7;
// force specific directories to relocate
if (RELOCATIONS & 0x1) {
lfs_dir_open(&lfs, &dir, "/parent");
lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
lfs_dir_close(&lfs, &dir) => 0;
}
if (RELOCATIONS & 0x2) {
lfs_dir_open(&lfs, &dir, "/parent/child");
lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
lfs_dir_close(&lfs, &dir) => 0;
}
// ok, now we move the file, this creates a move that needs to be
// fixed, possibly in a metadata-pair that needs to be relocated
//
// the worst case is if we need to relocate and we need to implicit
// fix the move in our parent before it falls out of date
lfs_rename(&lfs, "/parent/1.move_me", "/parent/child/1.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
lfs_file_close(&lfs, &files[3]) => 0;
// check that nothing was corrupted
lfs_dir_open(&lfs, &dir, "/parent") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "child") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_dir_open(&lfs, &dir, "/parent/child") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "1.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == sizeof("move me"));
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/parent/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.5") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.6") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.7") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.8") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;
'''
[[case]] # move fix in relocation with predecessor
in = "lfs.c"
define.RELOCATIONS = 'range(0x7+1)'
define.LFS_ERASE_CYCLES = 0xffffffff
code = '''
lfs_format(&lfs, &cfg) => 0;
lfs_mount(&lfs, &cfg) => 0;
lfs_mkdir(&lfs, "/parent") => 0;
lfs_mkdir(&lfs, "/parent/child") => 0;
lfs_mkdir(&lfs, "/parent/sibling") => 0;
lfs_file_open(&lfs, &file, "/parent/sibling/1.move_me",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "move me",
sizeof("move me")) => sizeof("move me");
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/sibling/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.1", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/sibling/2.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.2", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/0.before",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.3", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/2.after",
LFS_O_WRONLY | LFS_O_CREAT) => 0;
lfs_file_write(&lfs, &file, "test.4", 7) => 7;
lfs_file_close(&lfs, &file) => 0;
lfs_file_t files[4];
lfs_file_open(&lfs, &files[0], "/parent/sibling/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[1], "/parent/sibling/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[2], "/parent/child/0.before",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_open(&lfs, &files[3], "/parent/child/2.after",
LFS_O_WRONLY | LFS_O_TRUNC) => 0;
lfs_file_write(&lfs, &files[0], "test.5", 7) => 7;
lfs_file_write(&lfs, &files[1], "test.6", 7) => 7;
lfs_file_write(&lfs, &files[2], "test.7", 7) => 7;
lfs_file_write(&lfs, &files[3], "test.8", 7) => 7;
// force specific directories to relocate
if (RELOCATIONS & 0x1) {
lfs_dir_open(&lfs, &dir, "/parent");
lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
lfs_dir_close(&lfs, &dir) => 0;
}
if (RELOCATIONS & 0x2) {
lfs_dir_open(&lfs, &dir, "/parent/sibling");
lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
lfs_dir_close(&lfs, &dir) => 0;
}
if (RELOCATIONS & 0x4) {
lfs_dir_open(&lfs, &dir, "/parent/child");
lfs_testbd_setwear(&cfg, dir.m.pair[0], 0xffffffff) => 0;
lfs_testbd_setwear(&cfg, dir.m.pair[1], 0xffffffff) => 0;
lfs_dir_close(&lfs, &dir) => 0;
}
// ok, now we move the file, this creates a move that needs to be
// fixed, possibly in a metadata-pair that needs to be relocated
//
// and now relocations can force us to need to fix our move in either
// the parent or child before things break
lfs_rename(&lfs,
"/parent/sibling/1.move_me",
"/parent/child/1.move_me") => 0;
lfs_file_close(&lfs, &files[0]) => 0;
lfs_file_close(&lfs, &files[1]) => 0;
lfs_file_close(&lfs, &files[2]) => 0;
lfs_file_close(&lfs, &files[3]) => 0;
// check that nothing was corrupted
lfs_dir_open(&lfs, &dir, "/parent") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "child") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "sibling") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_dir_open(&lfs, &dir, "/parent/sibling") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_dir_open(&lfs, &dir, "/parent/child") => 0;
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "0.before") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "1.move_me") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == sizeof("move me"));
lfs_dir_read(&lfs, &dir, &info) => 1;
assert(strcmp(info.name, "2.after") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == 7);
lfs_dir_read(&lfs, &dir, &info) => 0;
lfs_dir_close(&lfs, &dir) => 0;
lfs_file_open(&lfs, &file, "/parent/sibling/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.5") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/sibling/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.6") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/0.before", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.7") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_file_open(&lfs, &file, "/parent/child/2.after", LFS_O_RDONLY) => 0;
lfs_file_read(&lfs, &file, buffer, 7) => 7;
assert(strcmp((char*)buffer, "test.8") == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;
'''