ovl: don't fail copy up if no fileattr support on upper

BugLink: https://bugs.launchpad.net/bugs/1960509
commit 94fd19752b28aa66c98e7991734af91dfc529f8f upstream.

Christoph Fritz is reporting that failure to copy up fileattr when upper
doesn't support fileattr or xattr results in a regression.

Return success in these failure cases; this reverts overlayfs to the old
behavior.

Add a pr_warn_once() in these cases to still let the user know about the
copy up failures.

Reported-by: Christoph Fritz <chf.fritz@googlemail.com>
Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags")
Cc: <stable@vger.kernel.org> # v5.15
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index b193d08a3dc367e23213d22eedd5dcbcf8a09d67..791b1916b098da1718db7aa30851df4c844e90cf 100644 (file)
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -157,7 +157,9 @@ static int ovl_copy_fileattr(struct inode *inode, struct path *old,
         */
        if (oldfa.flags & OVL_PROT_FS_FLAGS_MASK) {
                err = ovl_set_protattr(inode, new->dentry, &oldfa);
-               if (err)
+               if (err == -EPERM)
+                       pr_warn_once("copying fileattr: no xattr on upper\n");
+               else if (err)
                        return err;
        }
 
@@ -167,6 +169,14 @@ static int ovl_copy_fileattr(struct inode *inode, struct path *old,
 
        err = ovl_real_fileattr_get(new, &newfa);
        if (err) {
+               /*
+                * Returning an error if upper doesn't support fileattr will
+                * result in a regression, so revert to the old behavior.
+                */
+               if (err == -ENOTTY || err == -EINVAL) {
+                       pr_warn_once("copying fileattr: no support on upper\n");
+                       return 0;
+               }
                pr_warn("failed to retrieve upper fileattr (%pd2, err=%i)\n",
                        new, err);
                return err;