vfs: show_vfsstat: do not ignore errors from show_devname method

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>

diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 2256e7e23e678a11d2ab3fbaf1226a508f0ef1c8..3f1190d18991539087ddef41b922b458d16914b7 100644 (file)
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -199,6 +199,8 @@ 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 ");