commit e2a6ae7fe57c17199624e4d47826ec46ca57d546
author Paolo Bonzini <pbonzini@redhat.com> Mon Jun 05 14:38:54 2017 +0200
committer Fam Zheng <famz@redhat.com> Fri Jun 16 07:55:00 2017 +0800
tree 081efb61697d284b83fdf40c31195c8da0ac425e
parent 20fc71b25cfd8102b7f12a2b44133894ad90040a

block: access wakeup with atomic ops

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-6-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

block/sheepdog.c

diff --git a/block/sheepdog.c b/block/sheepdog.c
index a18315a..5ebf5d9 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -698,7 +698,8 @@
 
     srco->co = NULL;
     srco->ret = ret;
-    srco->finished = true;
+    /* Set srco->finished before reading bs->wakeup.  */
+    atomic_mb_set(&srco->finished, true);
     if (srco->bs) {
         bdrv_wakeup(srco->bs);
     }