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Made unknown file types a hard mount error, reverting

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I realized we really can't do anything if we find a file of unknown
type... If we don't understand a file's data structure, we can't really
do any bookkeeping. Allocating new blocks will probably corrupt unknown
files since we can't traverse any related B-trees, and mdir compaction
would be an absolute mess.

So, instead, just print an error and bail during mount.

Eventually we could at least fallback to readonly mode, but this is
currently a TODO item.

This also means the LFS_ERR_NOTSUP logic in lfsr_mtree_pathlookup is no
longer needed. Since, even with readonly fallback, we should never
mutate a filesystem with unknown file types.

Maybe in the future we could have a sort of known-but-not-supported mode
for file types? So special file types could not be support, but at least
understood enough to support traversal/remove/rename/etc?

Code changes:

           code          stack
  before: 33694           2592
  after:  33674 (-0.1%)   2592 (+0.0%)
This commit is contained in:
Christopher Haster
2024-06-09 14:18:02 -05:00
parent d63b5e4ea1
commit c72e3b24da
2 changed files with 9 additions and 76 deletions
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tests/test_incompat.toml
+2 -65
View File
@@ -351,69 +351,6 @@ code = '''
did, name, name_size))) => 0;
lfsr_unmount(&lfs) => 0;
// mount
lfsr_mount(&lfs, CFG) => 0;
// our file should appear as an unknown type
struct lfs_info info;
lfsr_stat(&lfs, "b", &info) => 0;
assert(strcmp(info.name, "b") == 0);
assert(info.type == 0x13);
assert(info.size == 0);
lfsr_dir_t dir;
lfsr_dir_open(&lfs, &dir, "/") => 0;
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, ".") == 0);
assert(info.type == LFS_TYPE_DIR);
assert(info.size == 0);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "..") == 0);
assert(info.type == LFS_TYPE_DIR);
assert(info.size == 0);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "a") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == strlen("hi a!"));
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "b") == 0);
assert(info.type == 0x13);
assert(info.size == 0);
lfsr_dir_read(&lfs, &dir, &info) => 0;
assert(strcmp(info.name, "c") == 0);
assert(info.type == LFS_TYPE_REG);
assert(info.size == strlen("hi c!"));
lfsr_dir_read(&lfs, &dir, &info) => LFS_ERR_NOENT;
lfsr_dir_close(&lfs, &dir) => 0;
// removing/renaming unknown files should return NOTSUP, we could
// remove the metadata entry, but we would probably leak stuff
lfsr_remove(&lfs, "b") => LFS_ERR_NOTSUP;
lfsr_rename(&lfs, "b", "d") => LFS_ERR_NOTSUP;
lfsr_rename(&lfs, "b", "c") => LFS_ERR_NOTSUP;
lfsr_rename(&lfs, "a", "b") => LFS_ERR_NOTSUP;
lfsr_file_open(&lfs, &file, "b",
LFS_O_RDONLY) => LFS_ERR_NOTSUP;
lfsr_file_open(&lfs, &file, "b",
LFS_O_WRONLY | LFS_O_CREAT) => LFS_ERR_NOTSUP;
lfsr_mkdir(&lfs, "b") => LFS_ERR_EXIST;
// we should also not try to use unknown files as dirs, which can
// be a bit tricky
lfsr_stat(&lfs, "b/d", &info) => LFS_ERR_NOTDIR;
lfsr_remove(&lfs, "b/e") => LFS_ERR_NOTDIR;
lfsr_rename(&lfs, "b/e", "d") => LFS_ERR_NOTDIR;
lfsr_rename(&lfs, "b/e", "c") => LFS_ERR_NOTDIR;
lfsr_rename(&lfs, "a", "b/e") => LFS_ERR_NOTDIR;
lfsr_file_open(&lfs, &file, "b/e",
LFS_O_RDONLY) => LFS_ERR_NOTDIR;
lfsr_file_open(&lfs, &file, "b/e",
LFS_O_WRONLY | LFS_O_CREAT) => LFS_ERR_NOTDIR;
lfsr_mkdir(&lfs, "b/e") => LFS_ERR_NOTDIR;
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_INVAL;
'''