fix: segfault if subarray is monitored but container is not

In this situation to->parent is null so "to" doesn't change to
parent container and to->metadata is still null.
This results in segmentation fault when checking
to->metadata->ss->external.
We should just skip this array as container is needed to move spares to.

Signed-off-by: Anna Czarnowska <anna.czarnowska@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/Monitor.c b/Monitor.c
index db4e8ccb..596fb6f4 100644
--- a/Monitor.c
+++ b/Monitor.c
@@ -833,6 +833,11 @@ static void try_spare_migration(struct state *statelist, struct alert_info *info
 			struct state *to = st;
 			unsigned long long min_size;
 
+			if (to->parent_dev != NoMdDev && !to->parent)
+				/* subarray monitored without parent container
+				 * we can't move spares here */
+				continue;
+			
 			if (to->parent)
 				/* member of a container */
 				to = to->parent;