On 2026/2/26 10:18, Inseob Kim wrote:
On Thu, Feb 26, 2026 at 10:50 AM Gao Xiang <[email protected]> wrote:
Hi Inseob,
On 2026/2/26 08:59, Inseob Kim wrote:
Add --nid and --path options to fsck.erofs to allow users to check
or extract specific sub-directories or files instead of the entire
filesystem.
This is useful for targeted data recovery or verifying specific
image components without the overhead of a full traversal.
Thanks for the patch!
Thank *you* for quick response!
Signed-off-by: Inseob Kim <[email protected]>
---
fsck/main.c | 50 ++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 40 insertions(+), 10 deletions(-)
diff --git a/fsck/main.c b/fsck/main.c
index ab697be..a7d9f46 100644
--- a/fsck/main.c
+++ b/fsck/main.c
@@ -39,6 +39,8 @@ struct erofsfsck_cfg {
bool preserve_owner;
bool preserve_perms;
bool dump_xattrs;
+ erofs_nid_t nid;
+ const char *inode_path;
bool nosbcrc;
};
static struct erofsfsck_cfg fsckcfg;
@@ -59,6 +61,8 @@ static struct option long_options[] = {
{"offset", required_argument, 0, 12},
{"xattrs", no_argument, 0, 13},
{"no-xattrs", no_argument, 0, 14},
+ {"nid", required_argument, 0, 15},
+ {"path", required_argument, 0, 16},
{"no-sbcrc", no_argument, 0, 512},
{0, 0, 0, 0},
};
@@ -110,6 +114,8 @@ static void usage(int argc, char **argv)
" --extract[=X] check if all files are well encoded,
optionally\n"
" extract to X\n"
" --offset=# skip # bytes at the beginning of
IMAGE\n"
+ " --nid=# check or extract from the target inode of nid
#\n"
+ " --path=X check or extract from the target inode of
path X\n"
" --no-sbcrc bypass the superblock checksum
verification\n"
" --[no-]xattrs whether to dump extended attributes (default
off)\n"
"\n"
@@ -245,6 +251,12 @@ static int erofsfsck_parse_options_cfg(int argc, char
**argv)
case 14:
fsckcfg.dump_xattrs = false;
break;
+ case 15:
+ fsckcfg.nid = (erofs_nid_t)atoll(optarg);
+ break;
+ case 16:
+ fsckcfg.inode_path = optarg;
+ break;
case 512:
fsckcfg.nosbcrc = true;
break;
@@ -981,7 +993,8 @@ static int erofsfsck_check_inode(erofs_nid_t pnid,
erofs_nid_t nid)
if (S_ISDIR(inode.i_mode)) {
struct erofs_dir_context ctx = {
- .flags = EROFS_READDIR_VALID_PNID,
+ .flags = (pnid == nid && nid != g_sbi.root_nid) ?
Does it relax the validatation check?
and does (nid == pnid && nid == fsckcfg.nid) work?
It shouldn't relax the existing validation check.
`erofsfsck_check_inode` is called with `err =
erofsfsck_check_inode(fsckcfg.nid, fsckcfg.nid);`.
* If a given path is not the root, `nid`'s parent `..` will differ
from `pnid`, causing failure. This condition only relaxes the starting
directory.
I just have a wild thought, if there is a directory which have
foo/
| - .. -> pointing to `foo` itself
- a/ -> pointing to `foo` directory too
will (pnid == nid && nid != g_sbi.root_nid) relaxs
the check for a/ ?
I'm not sure but you could double check.
* In the case of the root, `nid`'s parent `..` should indeed be
itself. So we can still validate.
If you have any better suggestions, I'll follow them.
+ 0 : EROFS_READDIR_VALID_PNID,
.pnid = pnid,
.dir = &inode,
.cb = erofsfsck_dirent_iter,
@@ -1033,6 +1046,8 @@ int main(int argc, char *argv[])
fsckcfg.preserve_owner = fsckcfg.superuser;
fsckcfg.preserve_perms = fsckcfg.superuser;
fsckcfg.dump_xattrs = false;
+ fsckcfg.nid = 0;
+ fsckcfg.inode_path = NULL;
err = erofsfsck_parse_options_cfg(argc, argv);
if (err) {
@@ -1068,22 +1083,37 @@ int main(int argc, char *argv[])
if (fsckcfg.extract_path)
erofsfsck_hardlink_init();
- if (erofs_sb_has_fragments(&g_sbi) && g_sbi.packed_nid > 0) {
- err = erofs_packedfile_init(&g_sbi, false);
+ if (fsckcfg.inode_path) {
+ struct erofs_inode inode = { .sbi = &g_sbi };
+
+ err = erofs_ilookup(fsckcfg.inode_path, &inode);
if (err) {
- erofs_err("failed to initialize packedfile: %s",
- erofs_strerror(err));
+ erofs_err("failed to lookup %s", fsckcfg.inode_path);
goto exit_hardlink;
}
It would be better to check if it's a directory.
My intention was that we support both directories and files. Or should
I create a separate flag like `--cat` in dump.erofs?
Ok, make sense.
Thanks,
Gao Xiang
