Clear tg->any_timer_armed[] when throttling timers are destroyed during AioContext attach/detach. Failure to do so causes throttling to hang because we believe the timer is already scheduled!
The following was broken at least since QEMU 2.10.0 with -drive iops=100: $ dd if=/dev/zero of=/dev/vdb oflag=direct count=1000 (qemu) stop (qemu) cont ...I/O is stuck... Reported-by: Yongxue Hong <yh...@redhat.com> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> --- v2: * Use timer_pending(tt->timers[i]) instead of token [Berto] * Fix s/destroy/destroyed/ typo [Eric] block/throttle-groups.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/block/throttle-groups.c b/block/throttle-groups.c index 6ba992c8d7..0a49f3c409 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -592,6 +592,17 @@ void throttle_group_attach_aio_context(ThrottleGroupMember *tgm, void throttle_group_detach_aio_context(ThrottleGroupMember *tgm) { ThrottleTimers *tt = &tgm->throttle_timers; + ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts); + + qemu_mutex_lock(&tg->lock); + if (timer_pending(tt->timers[0])) { + tg->any_timer_armed[0] = false; + } + if (timer_pending(tt->timers[1])) { + tg->any_timer_armed[1] = false; + } + qemu_mutex_unlock(&tg->lock); + throttle_timers_detach_aio_context(tt); tgm->aio_context = NULL; } -- 2.13.5