commit: Add NULL check for overlay_bs

I can't see how overlay_bs could become NULL with the current code, but
other code in this function already checks it and we can make Coverity
happy with this check, so let's add it.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit b1e1fa0c3afc7f671fbc24645bdf67949a5657e5)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/block/commit.c b/block/commit.c
index fba25e27a8947e7d901fd90aed34de226ede4ad6..66e3418e74d3e121b274c86d6011ee82f17b7ec3 100644 (file)
--- a/block/commit.c
+++ b/block/commit.c
@@ -91,7 +91,9 @@ static void commit_complete(BlockJob *job, void *opaque)
 
     /* Make sure overlay_bs and top stay around until bdrv_set_backing_hd() */
     bdrv_ref(top);
-    bdrv_ref(overlay_bs);
+    if (overlay_bs) {
+        bdrv_ref(overlay_bs);
+    }
 
     /* Remove base node parent that still uses BLK_PERM_WRITE/RESIZE before
      * the normal backing chain can be restored. */