From bd60436936ecebf2c683eef9ea561f2b949700f3 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 19 May 2014 17:56:01 +0200
Subject: [PATCH] qcow2: Fix memory leak in COW error path

This triggers if bs->drv becomes NULL in a concurrent request. This is
currently only the case when corruption prevention kicks in (i.e. at
most once per image, and after that it produces I/O errors).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/qcow2-cluster.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 76d2bcf63a..4208dc08b5 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -379,7 +379,8 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs,
     BLKDBG_EVENT(bs->file, BLKDBG_COW_READ);
 
     if (!bs->drv) {
-        return -ENOMEDIUM;
+        ret = -ENOMEDIUM;
+        goto out;
     }
 
     /* Call .bdrv_co_readv() directly instead of using the public block-layer