block: access copy_on_read with atomic ops

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-2-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/include/block/block_int.h b/include/block/block_int.h
index cb78c4fa82..49f2ebb95a 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -595,11 +595,6 @@ struct BlockDriverState {
 
     /* Protected by AioContext lock */
 
-    /* If true, copy read backing sectors into image.  Can be >1 if more
-     * than one client has requested copy-on-read.
-     */
-    int copy_on_read;
-
     /* If we are reading a disk image, give its size in sectors.
      * Generally read-only; it is written to by load_snapshot and
      * save_snaphost, but the block layer is quiescent during those.
@@ -633,6 +628,12 @@ struct BlockDriverState {
 
     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
 
+    /* If true, copy read backing sectors into image.  Can be >1 if more
+     * than one client has requested copy-on-read.  Accessed with atomic
+     * ops.
+     */
+    int copy_on_read;
+
     /* do we need to tell the quest if we have a volatile write cache? */
     int enable_write_cache;