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-rw-r--r--util/async.c32
1 files changed, 21 insertions, 11 deletions
diff --git a/util/async.c b/util/async.c
index d9f987e133..4266745dee 100644
--- a/util/async.c
+++ b/util/async.c
@@ -419,25 +419,32 @@ LuringState *aio_get_linux_io_uring(AioContext *ctx)
void aio_notify(AioContext *ctx)
{
- /* Write e.g. bh->scheduled before reading ctx->notify_me. Pairs
+ /*
+ * Write e.g. bh->flags before writing ctx->notified. Pairs with smp_mb in
+ * aio_notify_accept.
+ */
+ smp_wmb();
+ atomic_set(&ctx->notified, true);
+
+ /*
+ * Write ctx->notified before reading ctx->notify_me. Pairs
* with smp_mb in aio_ctx_prepare or aio_poll.
*/
smp_mb();
if (atomic_read(&ctx->notify_me)) {
event_notifier_set(&ctx->notifier);
- atomic_mb_set(&ctx->notified, true);
}
}
void aio_notify_accept(AioContext *ctx)
{
- if (atomic_xchg(&ctx->notified, false)
-#ifdef WIN32
- || true
-#endif
- ) {
- event_notifier_test_and_clear(&ctx->notifier);
- }
+ atomic_set(&ctx->notified, false);
+
+ /*
+ * Write ctx->notified before reading e.g. bh->flags. Pairs with smp_wmb
+ * in aio_notify.
+ */
+ smp_mb();
}
static void aio_timerlist_notify(void *opaque, QEMUClockType type)
@@ -445,8 +452,11 @@ static void aio_timerlist_notify(void *opaque, QEMUClockType type)
aio_notify(opaque);
}
-static void aio_context_notifier_dummy_cb(EventNotifier *e)
+static void aio_context_notifier_cb(EventNotifier *e)
{
+ AioContext *ctx = container_of(e, AioContext, notifier);
+
+ event_notifier_test_and_clear(&ctx->notifier);
}
/* Returns true if aio_notify() was called (e.g. a BH was scheduled) */
@@ -508,7 +518,7 @@ AioContext *aio_context_new(Error **errp)
aio_set_event_notifier(ctx, &ctx->notifier,
false,
- aio_context_notifier_dummy_cb,
+ aio_context_notifier_cb,
aio_context_notifier_poll);
#ifdef CONFIG_LINUX_AIO
ctx->linux_aio = NULL;