commit cb6d3ca07b8f62b47ef30c6a92caa3e8bd71248b
author Kevin Wolf <kwolf@redhat.com> Thu Apr 01 22:48:44 2010 +0200
committer Aurelien Jarno <aurelien@aurel32.net> Sat Apr 10 00:14:23 2010 +0200
tree 40a48a4634cc5ac2a32742be67e6c96bd65eab87
parent baf0b55a9e57b909b1f8b0f732c0b10242867418

block: Fix multiwrite error handling

When two requests of the same multiwrite batch fail, the callback of all
requests in that batch were called twice. This could have any kind of nasty
effects, in my case it lead to use after free and eventually a segfault.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

block.c

diff --git a/block.c b/block.c
index e891544..06ed08a 100644
--- a/block.c
+++ b/block.c
@@ -1740,7 +1740,7 @@
 {
     MultiwriteCB *mcb = opaque;
 
-    if (ret < 0) {
+    if (ret < 0 && !mcb->error) {
         mcb->error = ret;
         multiwrite_user_cb(mcb);
     }