ovl: set lower layer st_dev only if setting lower st_ino

commit 9f99e50d460ac7fd5f6c9b97aad0088c28c8656d upstream.

For broken hardlinks, we do not return lower st_ino, so we should
also not return lower pseudo st_dev.

Fixes: a0c5ad307ac0 ("ovl: relax same fs constraint for constant st_ino")
Cc: <stable@vger.kernel.org> #v4.15
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 94d2f8a8b779b0a8ddbfa11e782d1ac77575be1c..0dbbfedef54c04b62fb2b6ff70da69b34207cc80 100644 (file)
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -110,13 +110,10 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
                         * that the upper hardlink is not broken.
                         */
                        if (is_dir || lowerstat.nlink == 1 ||
-                           ovl_test_flag(OVL_INDEX, d_inode(dentry)))
+                           ovl_test_flag(OVL_INDEX, d_inode(dentry))) {
                                stat->ino = lowerstat.ino;
-
-                       if (samefs)
-                               WARN_ON_ONCE(stat->dev != lowerstat.dev);
-                       else
                                stat->dev = ovl_get_pseudo_dev(dentry);
+                       }
                }
                if (samefs) {
                        /*