Re: [PATCH for-6.2 v3 09/12] mirror: Check job_is_cancelled() earlier
06.08.2021 12:38, Max Reitz wrote: We must check whether the job is force-cancelled early in our main loop, most importantly before any `continue` statement. For example, we used to have `continue`s before our current checking location that are triggered by `mirror_flush()` failing. So, if `mirror_flush()` kept failing, force-cancelling the job would not terminate it. Jobs can be cancelled while they yield, and once they are (force-cancelled), they should not generate new I/O requests. Therefore, we should put the check after the last yield before mirror_iteration() is invoked. Buglink:https://gitlab.com/qemu-project/qemu/-/issues/462 Signed-off-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy -- Best regards, Vladimir
Re: [PATCH for-6.2 v3 09/12] mirror: Check job_is_cancelled() earlier
On Fri, Aug 06, 2021 at 11:38:56AM +0200, Max Reitz wrote: > We must check whether the job is force-cancelled early in our main loop, > most importantly before any `continue` statement. For example, we used > to have `continue`s before our current checking location that are > triggered by `mirror_flush()` failing. So, if `mirror_flush()` kept > failing, force-cancelling the job would not terminate it. > > Jobs can be cancelled while they yield, and once they are > (force-cancelled), they should not generate new I/O requests. > Therefore, we should put the check after the last yield before > mirror_iteration() is invoked. > > Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462 > Signed-off-by: Max Reitz > --- > block/mirror.c | 10 +- > 1 file changed, 5 insertions(+), 5 deletions(-) Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
[PATCH for-6.2 v3 09/12] mirror: Check job_is_cancelled() earlier
We must check whether the job is force-cancelled early in our main loop,
most importantly before any `continue` statement. For example, we used
to have `continue`s before our current checking location that are
triggered by `mirror_flush()` failing. So, if `mirror_flush()` kept
failing, force-cancelling the job would not terminate it.
Jobs can be cancelled while they yield, and once they are
(force-cancelled), they should not generate new I/O requests.
Therefore, we should put the check after the last yield before
mirror_iteration() is invoked.
Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462
Signed-off-by: Max Reitz
---
block/mirror.c | 10 +-
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 024fa2dcea..bf1d50ff1c 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1000,6 +1000,11 @@ static int coroutine_fn mirror_run(Job *job, Error
**errp)
job_pause_point(&s->common.job);
+if (job_is_cancelled(&s->common.job)) {
+ret = 0;
+goto immediate_exit;
+}
+
cnt = bdrv_get_dirty_count(s->dirty_bitmap);
/* cnt is the number of dirty bytes remaining and s->bytes_in_flight is
* the number of bytes currently being processed; together those are
@@ -1078,8 +1083,6 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
break;
}
-ret = 0;
-
if (job_is_ready(&s->common.job) && !should_complete) {
delay_ns = (s->in_flight == 0 &&
cnt == 0 ? BLOCK_JOB_SLICE_TIME : 0);
@@ -1087,9 +1090,6 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
trace_mirror_before_sleep(s, cnt, job_is_ready(&s->common.job),
delay_ns);
job_sleep_ns(&s->common.job, delay_ns);
-if (job_is_cancelled(&s->common.job)) {
-break;
-}
s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
}
--
2.31.1
