This patch doesn't actually fix any bug, just paves the way for fixing mark
and group pinning.
Reviewed-by: NAmir Goldstein <amir73il@gmail.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.12
Signed-off-by: NJan Kara <jack@suse.cz>