aio-wait: draw equivalence between AIO_WAIT_WHILE() and AIO_WAIT_WHIL…

…E_UNLOCKED()

Now that the AioContext lock no longer exists, AIO_WAIT_WHILE() and
AIO_WAIT_WHILE_UNLOCKED() are equivalent.

A future patch will get rid of AIO_WAIT_WHILE_UNLOCKED().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-ID: <20231205182011.1976568-10-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

include/block/aio-wait.h

@@ -63,9 +63,6 @@ extern AioWait global_aio_wait;
  * @ctx: the aio context, or NULL if multiple aio contexts (for which the
  *       caller does not hold a lock) are involved in the polling condition.
  * @cond: wait while this conditional expression is true
- * @unlock: whether to unlock and then lock again @ctx. This applies
- * only when waiting for another AioContext from the main loop.
- * Otherwise it's ignored.
  *
  * Wait while a condition is true.  Use this to implement synchronous
  * operations that require event loop activity.
@@ -78,7 +75,7 @@ extern AioWait global_aio_wait;
  * wait on conditions between two IOThreads since that could lead to deadlock,
  * go via the main loop instead.
  */
-#define AIO_WAIT_WHILE_INTERNAL(ctx, cond, unlock) ({              \
+#define AIO_WAIT_WHILE_INTERNAL(ctx, cond) ({                      \
     bool waited_ = false;                                          \
     AioWait *wait_ = &global_aio_wait;                             \
     AioContext *ctx_ = (ctx);                                      \
@@ -95,24 +92,19 @@ extern AioWait global_aio_wait;
         assert(qemu_get_current_aio_context() ==                   \
                qemu_get_aio_context());                            \
         while ((cond)) {                                           \
-            if (unlock && ctx_) {                                  \
-                aio_context_release(ctx_);                         \
-            }                                                      \
             aio_poll(qemu_get_aio_context(), true);                \
-            if (unlock && ctx_) {                                  \
-                aio_context_acquire(ctx_);                         \
-            }                                                      \
             waited_ = true;                                        \
         }                                                          \
     }                                                              \
     qatomic_dec(&wait_->num_waiters);                              \
     waited_; })
 
 #define AIO_WAIT_WHILE(ctx, cond)                                  \
-    AIO_WAIT_WHILE_INTERNAL(ctx, cond, true)
+    AIO_WAIT_WHILE_INTERNAL(ctx, cond)
 
+/* TODO replace this with AIO_WAIT_WHILE() in a future patch */
 #define AIO_WAIT_WHILE_UNLOCKED(ctx, cond)                         \
-    AIO_WAIT_WHILE_INTERNAL(ctx, cond, false)
+    AIO_WAIT_WHILE_INTERNAL(ctx, cond)
 
 /**
  * aio_wait_kick: