block: Fix deadlocks in bdrv_graph_wrunlock()

[mirror_qemu.git] / include / block / graph-lock.h

diff --git a/include/block/graph-lock.h b/include/block/graph-lock.h
index 7574a2de5b162bfe02a456a7848f04b3b405b397..22b5db1ed962f9bf5dd4d8a3d661d7b5dcde7b0e 100644 (file)
--- a/include/block/graph-lock.h
+++ b/include/block/graph-lock.h
@@ -111,17 +111,33 @@ void unregister_aiocontext(AioContext *ctx);
  * The wrlock can only be taken from the main loop, with BQL held, as only the
  * main loop is allowed to modify the graph.
  *
+ * If @bs is non-NULL, its AioContext is temporarily released.
+ *
  * This function polls. Callers must not hold the lock of any AioContext other
- * than the current one.
+ * than the current one and the one of @bs.
  */
-void bdrv_graph_wrlock(void) TSA_ACQUIRE(graph_lock) TSA_NO_TSA;
+void no_coroutine_fn TSA_ACQUIRE(graph_lock) TSA_NO_TSA
+bdrv_graph_wrlock(BlockDriverState *bs);
 
 /*
  * bdrv_graph_wrunlock:
  * Write finished, reset global has_writer to 0 and restart
  * all readers that are waiting.
+ *
+ * If @bs is non-NULL, its AioContext is temporarily released.
+ */
+void no_coroutine_fn TSA_RELEASE(graph_lock) TSA_NO_TSA
+bdrv_graph_wrunlock(BlockDriverState *bs);
+
+/*
+ * bdrv_graph_wrunlock_ctx:
+ * Write finished, reset global has_writer to 0 and restart
+ * all readers that are waiting.
+ *
+ * If @ctx is non-NULL, its lock is temporarily released.
  */
-void bdrv_graph_wrunlock(void) TSA_RELEASE(graph_lock) TSA_NO_TSA;
+void no_coroutine_fn TSA_RELEASE(graph_lock) TSA_NO_TSA
+bdrv_graph_wrunlock_ctx(AioContext *ctx);
 
 /*
  * bdrv_graph_co_rdlock: