From: Amir Goldstein <amir73il@gmail.com>
Date: Wed, 11 Apr 2018 17:09:29 +0000 (+0300)
Subject: ovl: set lower layer st_dev only if setting lower st_ino
X-Git-Tag: v4.15.18~1
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c4f45cf301e6fc024ef5eb3eca234c659d751cb8;p=linux

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 94d2f8a8b779..0dbbfedef54c 100644
--- 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) {
 			/*