[Qemu-devel] [PATCH v4 04/11] quorum: Fix close path

[Max Reitz <mreitz@redhat.com>]

bdrv_unref() can lead to bdrv_close(), which in turn will result in
bdrv_drain_all(). This function will later be called blk_drain_all() and
iterate only over the BlockBackends for which blk_is_inserted() holds
true; therefore, bdrv_is_inserted() and thus quorum_is_inserted() will
probably be called.

This patch makes quorum_is_inserted() aware of the fact that some
children may have been closed already.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/quorum.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/quorum.c b/block/quorum.c
index 7a75cea..5ae2398 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -1005,6 +1005,7 @@ static void quorum_close(BlockDriverState *bs)
 
     for (i = 0; i < s->num_children; i++) {
         bdrv_unref(s->bs[i]);
+        s->bs[i] = NULL;
     }
 
     g_free(s->bs);
@@ -1070,7 +1071,7 @@ static bool quorum_is_inserted(BlockDriverState *bs)
     int i;
 
     for (i = 0; i < s->num_children; i++) {
-        if (!bdrv_is_inserted(s->bs[i])) {
+        if (s->bs[i] && !bdrv_is_inserted(s->bs[i])) {
             return false;
         }
     }
-- 
2.1.0