block: fix qcow2_co_flush deadlock

If qcow2_cache_flush failed, s->lock will not be unlock.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/block/qcow2.c b/block/qcow2.c
index a181932b67..ef057d31e0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1113,11 +1113,13 @@ static int qcow2_co_flush(BlockDriverState *bs)
     qemu_co_mutex_lock(&s->lock);
     ret = qcow2_cache_flush(bs, s->l2_table_cache);
     if (ret < 0) {
+        qemu_co_mutex_unlock(&s->lock);
         return ret;
     }
 
     ret = qcow2_cache_flush(bs, s->refcount_block_cache);
     if (ret < 0) {
+        qemu_co_mutex_unlock(&s->lock);
         return ret;
     }
     qemu_co_mutex_unlock(&s->lock);