From 0fd56fb8443d52a20d6bd8b4b543c4a8f9d0756d Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Fri, 21 Mar 2014 13:55:19 +0100 Subject: [PATCH] mirror: fix early wake from sleep due to aio The mirror blockjob coroutine rate-limits itself by sleeping. The coroutine also performs I/O asynchronously so it's important that the aio callback doesn't wake the coroutine early as that breaks rate-limiting. Reported-by: Joaquim Barrera Signed-off-by: Stefan Hajnoczi (cherry picked from commit 7b770c720b28b8ac5b82ae431f2f354b7f8add91) Signed-off-by: Michael Roth --- block/mirror.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/block/mirror.c b/block/mirror.c index 9bfc22f571..2d9104efc0 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -95,7 +95,14 @@ static void mirror_iteration_done(MirrorOp *op, int ret) } g_slice_free(MirrorOp, op); - qemu_coroutine_enter(s->common.co, NULL); + + /* Enter coroutine when it is not sleeping. The coroutine sleeps to + * rate-limit itself. The coroutine will eventually resume since there is + * a sleep timeout so don't wake it early. + */ + if (s->common.busy) { + qemu_coroutine_enter(s->common.co, NULL); + } } static void mirror_write_complete(void *opaque, int ret)