[PATCH] block/quorum.c: Decrease child index when del_child

[Zhang Chen <chen.zhang@intel.com >]

From: Zhang Chen <chen.zhang@intel.com>

Fix this bug:
colo: Can not recover colo after svm failover twice
https://bugs.launchpad.net/bugs/1881231

The child index still be hold when it be deleted, the max num is 32.

Reported-by: Ye.Zou <ye.zou@zstack.io>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
---
 block/quorum.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/quorum.c b/block/quorum.c
index 7cf7ab1546..f71bd4e19d 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -1099,6 +1099,7 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child,
             (s->num_children - i - 1) * sizeof(BdrvChild *));
     s->children = g_renew(BdrvChild *, s->children, --s->num_children);
     bdrv_unref_child(bs, child);
+    s->next_child_index--;
 
     bdrv_drained_end(bs);
 }
-- 
2.17.1