From e79325308454814d968dd3e06cd261a269716675 Mon Sep 17 00:00:00 2001
From: David Teigland <teigland@redhat.com>
Date: Tue, 23 Feb 2016 15:44:14 -0600
Subject: [PATCH] lvmlockd: fix sparse snapshot case

A snapshot can be created without a real origin LV
in this case, so there's no lock to use.
---
 lib/locking/lvmlockd.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/locking/lvmlockd.c b/lib/locking/lvmlockd.c
index e78e2cb46..c55f2b50d 100644
--- a/lib/locking/lvmlockd.c
+++ b/lib/locking/lvmlockd.c
@@ -2331,6 +2331,12 @@ int lockd_init_lv(struct cmd_context *cmd, struct volume_group *vg, struct logic
 		 * represents itself and all associated cow snapshots.
 		 */
 
+		if (!lp->origin_name) {
+			/* Sparse LV case. We require a lock from the origin LV. */
+			log_error("Cannot create snapshot without origin LV in shared VG.");
+			return 0;
+		}
+
 		if (!(origin_lv = find_lv(vg, lp->origin_name))) {
 			log_error("Failed to find origin LV %s/%s", vg->name, lp->origin_name);
 			return 0;