From: Stefan Hajnoczi <stefa...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Message-ID: <20230808155852.2745350-2-stefa...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Kevin Wolf <kw...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/io.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/block/io.c b/block/io.c
index 76e7df18d8..4f32d6aa6e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -593,8 +593,14 @@ static void coroutine_fn
tracked_request_end(BdrvTrackedRequest *req)
qemu_co_mutex_lock(&req->bs->reqs_lock);
QLIST_REMOVE(req, list);
- qemu_co_queue_restart_all(&req->wait_queue);
qemu_co_mutex_unlock(&req->bs->reqs_lock);
+
+ /*
+ * At this point qemu_co_queue_wait(&req->wait_queue, ...) won't be called
+ * anymore because the request has been removed from the list, so it's safe
+ * to restart the queue outside reqs_lock to minimize the critical section.
+ */
+ qemu_co_queue_restart_all(&req->wait_queue);
}
/**
--
2.41.0
