We get occasional reports of lookup errors due to mismatched
origin ftype from users that re-format a lower squashfs image.
Commit 13c6ad0f45fd ("ovl: document lower modification caveats")
tries to discourage the practice of re-formating lower layers and
describes the expected behavior as undefined.
Commit b0e0f69731cd ("ovl: restrict lower null uuid for "xino=auto"")
limits the configurations in which origin file handles are followed.
In addition to these measures, change the behavior in case of detecting
a mismatch origin ftype in lookup to issue a warning, not follow origin,
but not fail the lookup operation either.
That should make overall more users happy without any big consequences.
Link: https://lore.kernel.org/linux-unionfs/CAOQ4uxgPq9E9xxwU2CDyHy-_yCZZeymg+3n+-6AqkGGE1YtwvQ@xxxxxxxxxxxxxx/
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
Miklos,
I am getting tired of dealing with lower squashfs related reports.
How about this?
It passes the xfstests quick tests and no, I do not have a reproducer
for origin mismatch, so will wait for Byron to test the patch.
Thanks,
Amir.
fs/overlayfs/namei.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 71e264e2f16b..850c0a37f1f0 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -392,7 +392,7 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
upperdentry, d_inode(upperdentry)->i_mode & S_IFMT,
d_inode(origin)->i_mode & S_IFMT);
dput(origin);
- return -EIO;
+ return -EINVAL;
}
static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
@@ -408,7 +408,7 @@ static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
kfree(fh);
if (err) {
- if (err == -ESTALE)
+ if (err == -ESTALE || err == -EINVAL)
return 0;
return err;
}
--
2.25.1
