[Qemu-devel] [PATCH 1/2] block: add the support to drain throttled requests

[zwu . kernel]

From: Zhi Yong Wu <address@hidden>

Signed-off-by: Paolo Bonzini <address@hidden>
Signed-off-by: Zhi Yong Wu <address@hidden>
---
 block.c |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/block.c b/block.c
index b88ee90..1fbf4dd 100644
--- a/block.c
+++ b/block.c
@@ -862,8 +862,22 @@ void bdrv_close_all(void)
 void bdrv_drain_all(void)
 {
     BlockDriverState *bs;
+    bool busy;
 
-    qemu_aio_flush();
+    do {
+        busy = false;
+        qemu_aio_flush();
+
+        /* FIXME: We do not have timer support here, so this is effectively
+         * a busy wait.
+         */
+        QTAILQ_FOREACH(bs, &bdrv_states, list) {
+            if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+                qemu_co_queue_restart_all(&bs->throttled_reqs);
+                busy = true;
+            }
+        }
+    } while (busy);
 
     /* If requests are still pending there is a bug somewhere */
     QTAILQ_FOREACH(bs, &bdrv_states, list) {
-- 
1.7.6