1 files changed, 9 insertions, 0 deletions
diff --git a/include/block/aio.h b/include/block/aio.h
index d128558f1d..0f65a3cc9e 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -22,6 +22,7 @@
 #include "qemu/event_notifier.h"
 #include "qemu/thread.h"
 #include "qemu/timer.h"
+#include "block/graph-lock.h"
 
 typedef struct BlockAIOCB BlockAIOCB;
 typedef void BlockCompletionFunc(void *opaque, int ret);
@@ -127,6 +128,14 @@ struct AioContext {
     /* Used by AioContext users to protect from multi-threaded access.  */
     QemuRecMutex lock;
 
+    /*
+     * Keep track of readers and writers of the block layer graph.
+     * This is essential to avoid performing additions and removal
+     * of nodes and edges from block graph while some
+     * other thread is traversing it.
+     */
+    BdrvGraphRWlock *bdrv_graph;
+
     /* The list of registered AIO handlers.  Protected by ctx->list_lock. */
     AioHandlerList aio_handlers;