1 files changed, 14 insertions, 18 deletions

diff --git a/include/block/aio.h b/include/block/aio.h
index a92511b..c23de3c 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -60,8 +60,14 @@ struct AioContext {
      */
     int walking_handlers;
 
+    /* Used to avoid unnecessary event_notifier_set calls in aio_notify.
+     * Writes protected by lock or BQL, reads are lockless.
+     */
+    bool dispatching;
+
     /* lock to protect between bh's adders and deleter */
     QemuMutex bh_lock;
+
     /* Anchor of the list of Bottom Halves belonging to the context */
     struct QEMUBH *first_bh;
 
@@ -83,6 +89,9 @@ struct AioContext {
     QEMUTimerListGroup tlg;
 };
 
+/* Used internally to synchronize aio_poll against qemu_bh_schedule.  */
+void aio_set_dispatching(AioContext *ctx, bool dispatching);
+
 /**
  * aio_context_new: Allocate a new AioContext.
  *
@@ -205,9 +214,9 @@ bool aio_pending(AioContext *ctx);
 /* Progress in completing AIO work to occur.  This can issue new pending
  * aio as a result of executing I/O completion or bh callbacks.
  *
- * If there is no pending AIO operation or completion (bottom half),
- * return false.  If there are pending AIO operations of bottom halves,
- * return true.
+ * Return whether any progress was made by executing AIO or bottom half
+ * handlers.  If @blocking == true, this should always be true except
+ * if someone called aio_notify.
  *
  * If there are no pending bottom halves, but there are pending AIO
  * operations, it may not be possible to make any progress without
@@ -220,7 +229,7 @@ bool aio_poll(AioContext *ctx, bool blocking);
 #ifdef CONFIG_POSIX
 /* Register a file descriptor and associated callbacks.  Behaves very similarly
  * to qemu_set_fd_handler2.  Unlike qemu_set_fd_handler2, these callbacks will
- * be invoked when using qemu_aio_wait().
+ * be invoked when using aio_poll().
  *
  * Code that invokes AIO completion functions should rely on this function
  * instead of qemu_set_fd_handler[2].
@@ -234,7 +243,7 @@ void aio_set_fd_handler(AioContext *ctx,
 
 /* Register an event notifier and associated callbacks.  Behaves very similarly
  * to event_notifier_set_handler.  Unlike event_notifier_set_handler, these callbacks
- * will be invoked when using qemu_aio_wait().
+ * will be invoked when using aio_poll().
  *
  * Code that invokes AIO completion functions should rely on this function
  * instead of event_notifier_set_handler.
@@ -251,19 +260,6 @@ GSource *aio_get_g_source(AioContext *ctx);
 /* Return the ThreadPool bound to this AioContext */
 struct ThreadPool *aio_get_thread_pool(AioContext *ctx);
 
-/* Functions to operate on the main QEMU AioContext.  */
-
-bool qemu_aio_wait(void);
-void qemu_aio_set_event_notifier(EventNotifier *notifier,
-                                 EventNotifierHandler *io_read);
-
-#ifdef CONFIG_POSIX
-void qemu_aio_set_fd_handler(int fd,
-                             IOHandler *io_read,
-                             IOHandler *io_write,
-                             void *opaque);
-#endif
-
 /**
  * aio_timer_new:
  * @ctx: the aio context