@@ -90,6 +90,11 @@ void qemu_aio_coroutine_enter(AioContext *ctx, Coroutine *co);
void coroutine_fn qemu_coroutine_yield(void);
/**
+ * Get the AioContext of the given coroutine
+ */
+AioContext *coroutine_fn qemu_coroutine_get_aio_context(Coroutine *co);
+
+/**
* Get the currently executing coroutine
*/
Coroutine *coroutine_fn qemu_coroutine_self(void);
@@ -288,6 +288,18 @@ static void bdrv_co_drain_bh_cb(void *opaque)
BlockDriverState *bs = data->bs;
if (bs) {
+ AioContext *ctx = bdrv_get_aio_context(bs);
+ AioContext *co_ctx = qemu_coroutine_get_aio_context(co);
+
+ /*
+ * When the coroutine yielded, the lock for its home context was
+ * released, so we need to re-acquire it here. If it explicitly
+ * acquired a different context, the lock is still held and we don't
+ * want to lock it a second time (or AIO_WAIT_WHILE() would hang).
+ */
+ if (ctx == co_ctx) {
+ aio_context_acquire(ctx);
+ }
bdrv_dec_in_flight(bs);
if (data->begin) {
bdrv_do_drained_begin(bs, data->recursive, data->parent,
@@ -296,6 +308,9 @@ static void bdrv_co_drain_bh_cb(void *opaque)
bdrv_do_drained_end(bs, data->recursive, data->parent,
data->ignore_bds_parents);
}
+ if (ctx == co_ctx) {
+ aio_context_release(ctx);
+ }
} else {
assert(data->begin);
bdrv_drain_all_begin();
@@ -198,3 +198,8 @@ bool qemu_coroutine_entered(Coroutine *co)
{
return co->caller;
}
+
+AioContext *coroutine_fn qemu_coroutine_get_aio_context(Coroutine *co)
+{
+ return co->ctx;
+}