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Added detection/handling of unknown file types

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This adds a couple things so our unknown file types don't just cause our
filesystem to fall over:

- lfsr_mount now prints a warning on any unknown file types found at
  mount time. Since we're already iterating over all files to find
  orphans, this is basically free.

- Added LFS_TYPE_UNKNOWN to represent files with an unknown/unsupported
  type. This is now returned by lfsr_stat/lfsr_dir_read for files of any
  unknow type.

- Added LFS_ERR_NOTSUP. This is now returned by functions that attempt
  to modify a file of unknown type, and my have more use cases in the
  future.

  It's tempting to allow remove/rename on unknown file types, but since
  we don't know what data structures these may be referencing, doing so
  would likely leak storage. Or worse. Shrubs for example would just
  explode if you only moved the metadata entry.

This also adds test_incompat_unknown to test these cases.

Code changes are minimal, though there are a number of extra conditions
to check for unknown file types. The lfsr_mount condition is
particularly fun as it should be completely optimized out when debug
statements are disabled:

           code          stack
  before: 33670           2592
  after:  33710 (+0.1%)   2592 (+0.0%)
This commit is contained in:
Christopher Haster
2024-06-09 13:12:27 -05:00
parent 1e41fc07fe
commit 7fad472af5
3 changed files with 156 additions and 14 deletions
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lfs.c
+47 -13
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@@ -910,6 +910,13 @@ static inline bool lfsr_tag_q(lfsr_tag_t tag) {
return tag & LFSR_TAG_Q;
}
static inline bool lfsr_tag_isunknown(lfsr_tag_t tag) {
return tag != LFSR_TAG_REG
&& tag != LFSR_TAG_DIR
&& tag != LFSR_TAG_BOOKMARK
&& tag != LFSR_TAG_ORPHAN;
}
static inline bool lfsr_tag_isinternal(lfsr_tag_t tag) {
return tag & LFSR_TAG_INTERNAL;
}
@@ -7486,6 +7493,7 @@ enum {
// - 0 => path is valid, file NOT found
// - EXIST => path is valid, file found
// - INVAL => path is valid, but points to root
// - NOTSUP => path is valid, but points to unknown file type
// - NOENT => path is NOT valid, intermediate dir missing
// - NOTDIR => path is NOT valid, intermediate dir is not a dir
//
@@ -7559,8 +7567,11 @@ static int lfsr_mtree_pathlookup(lfs_t *lfs, const lfsr_mtree_t *mtree,
// the root dir doesn't have an mdir really, so it's always
// a special case
return (mdir.mid == -1)
? LFS_ERR_INVAL
: LFS_ERR_EXIST;
? LFS_ERR_INVAL
// unknown file type?
: (lfsr_tag_isunknown(tag))
? LFS_ERR_NOTSUP
: LFS_ERR_EXIST;
}
// found another name
@@ -8589,21 +8600,34 @@ static int lfsr_mountinited(lfs_t *lfs) {
// check for any orphaned files
for (lfs_size_t rid = 0; rid < tinfo.u.mdir.rbyd.weight; rid++) {
err = lfsr_rbyd_lookup(lfs, &tinfo.u.mdir.rbyd,
rid, LFSR_TAG_ORPHAN,
NULL);
if (err && err != LFS_ERR_NOENT) {
lfsr_tag_t tag;
err = lfsr_rbyd_sublookup(lfs, &tinfo.u.mdir.rbyd,
rid, LFSR_TAG_NAME,
&tag, NULL);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
// name 0 should be reserved
LFS_ASSERT(tag != (LFSR_TAG_NAME + 0));
// found an orphaned file?
if (err != LFS_ERR_NOENT) {
if (tag == LFSR_TAG_ORPHAN) {
LFS_DEBUG("Found orphaned file "
"%"PRId32".%"PRId32,
lfsr_mid_bid(lfs, tinfo.u.mdir.mid)
>> lfs->mdir_bits,
rid);
lfs->hasorphans = true;
// found an unknown file type?
} else if (lfsr_tag_isunknown(tag)) {
LFS_WARN("Found unknown file type "
"%"PRId32".%"PRId32" 0x%"PRIx16,
lfsr_mid_bid(lfs, tinfo.u.mdir.mid)
>> lfs->mdir_bits,
rid,
lfsr_tag_subtype(tag));
}
}
@@ -9136,11 +9160,13 @@ int lfsr_mkdir(lfs_t *lfs, const char *path) {
err = lfsr_mtree_pathlookup(lfs, &lfs->mtree, path,
&mdir, &tag,
&did, &name, &name_size);
if (err && err != LFS_ERR_EXIST && err != LFS_ERR_INVAL) {
if (err && err != LFS_ERR_EXIST
&& err != LFS_ERR_INVAL
&& err != LFS_ERR_NOTSUP) {
return err;
}
// already exists? note orphans don't really exist
bool exists = (err == LFS_ERR_EXIST || err == LFS_ERR_INVAL);
bool exists = (bool)err;
if (exists && tag != LFSR_TAG_ORPHAN) {
return LFS_ERR_EXIST;
}
@@ -9581,7 +9607,11 @@ static int lfsr_stat_(lfs_t *lfs, const lfsr_mdir_t *mdir,
lfsr_tag_t tag, lfsr_data_t name,
struct lfs_info *info) {
// get file type from the tag
info->type = lfsr_tag_subtype(tag);
if (tag == LFSR_TAG_REG || tag == LFSR_TAG_DIR) {
info->type = lfsr_tag_subtype(tag);
} else {
info->type = LFS_TYPE_UNKNOWN;
}
// read the file name
LFS_ASSERT(lfsr_data_size(name) <= LFS_NAME_MAX);
@@ -9633,7 +9663,9 @@ int lfsr_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
int err = lfsr_mtree_pathlookup(lfs, &lfs->mtree, path,
&mdir, &tag,
NULL, &name, &name_size);
if (err && err != LFS_ERR_EXIST && err != LFS_ERR_INVAL) {
if (err && err != LFS_ERR_EXIST
&& err != LFS_ERR_INVAL
&& err != LFS_ERR_NOTSUP) {
return err;
}
// doesn't exist? note orphans don't really exist
@@ -9666,7 +9698,8 @@ int lfsr_dir_open(lfs_t *lfs, lfsr_dir_t *dir, const char *path) {
int err = lfsr_mtree_pathlookup(lfs, &lfs->mtree, path,
&mdir, &tag,
NULL, NULL, NULL);
if (err && err != LFS_ERR_EXIST && err != LFS_ERR_INVAL) {
if (err && err != LFS_ERR_EXIST
&& err != LFS_ERR_INVAL) {
return err;
}
// doesn't exist? note orphans don't really exist
@@ -10025,7 +10058,8 @@ int lfsr_file_opencfg(lfs_t *lfs, lfsr_file_t *file,
int err = lfsr_mtree_pathlookup(lfs, &lfs->mtree, path,
&file->o.mdir, &tag,
&did, &name, &name_size);
if (err && err != LFS_ERR_EXIST && err != LFS_ERR_INVAL) {
if (err && err != LFS_ERR_EXIST
&& err != LFS_ERR_INVAL) {
return err;
}