vfs: show_vfsstat: do not ignore errors from show_devname method

[ Upstream commit 5f8d498d4364f544fee17125787a47553db02afa ]

Explicitly check show_devname method return code and bail out in case
of an error.  This fixes regression introduced by commit 9d4d65748a5c.

Cc: stable@vger.kernel.org
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 8db932da40091b44f2a8df49e921d942f2291908..a5644c41a1828a3a71255311f675cb025eaf2534 100644 (file)
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -196,6 +196,8 @@ static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
        if (sb->s_op->show_devname) {
                seq_puts(m, "device ");
                err = sb->s_op->show_devname(m, mnt_path.dentry);
+               if (err)
+                       goto out;
        } else {
                if (r->mnt_devname) {
                        seq_puts(m, "device ");