On Tue, Mar 4, 2025 at 8:34 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
>
> Hi,
>
> 在 2025/03/04 20:22, Xiao Ni 写道:
> > On Tue, Mar 4, 2025 at 7:03 PM Paul Menzel <pmenzel@xxxxxxxxxxxxx> wrote:
> >>
> >> Dear Xiao,
> >>
> >>
> >> Thank you for your patch. A minor thing, I’d add a verb to the
> >> summary/title:
> >
> > Thanks for pointing out this.
> >
> >>
> >>> Add wait barrier before …
> >>
> >> Am 04.03.25 um 11:41 schrieb Xiao Ni:
> >>> raid10_handle_discard should wait barrier before returning a discard bio
> >>> which has REQ_NOWAIT. And there is no need to print warning calltrace
> >>> if a discard bio has REQ_NOWAIT flag. Quality engineer usually checks
> >>> dmesg and reports error if dmesg has warning/error calltrace.
> >>
> >> As written in the other thread, please add, why the warning is not
> >> useful. Somebody added that warning probably with some reason.
> >
> > For me, it's overkilled to print a warning calltrace if one bio has
> > REQ_NOWAIT flag. It's a normal request rather than a dangerous thing
> > happens, right? If we want to print some logs, we can use pr_info
> > rather than WARN_ON_ONCE.
>
> Just take a look at block layer and other drivers, there is no such
> warn in this case. And I think you can add a fixtag:
>
> c9aa889b035f ("md: raid10 add nowait support")
>
> This commit just forbid discard with REQ_NOWAIT in raid10.
Ok.
>
> BTW, I think the abouve checking can be removed as well:
>
> if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
> return -EAGAIN;
Now we can't remove it. raid10_handle_discard doesn't consider the
reshape situation. So raid10 will use the old way to handle discard if
reshape happens.
Regards
Xiao
>
> Thanks,
> Kuai
>
> >
> > Best Regards
> > Xiao
> >
> >>
> >>> Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
> >>> ---
> >>> drivers/md/raid10.c | 3 +--
> >>> 1 file changed, 1 insertion(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> >>> index 15b9ae5bf84d..7bbc04522f26 100644
> >>> --- a/drivers/md/raid10.c
> >>> +++ b/drivers/md/raid10.c
> >>> @@ -1631,11 +1631,10 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
> >>> if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
> >>> return -EAGAIN;
> >>>
> >>> - if (WARN_ON_ONCE(bio->bi_opf & REQ_NOWAIT)) {
> >>> + if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
> >>> bio_wouldblock_error(bio);
> >>> return 0;
> >>> }
> >>> - wait_barrier(conf, false);
> >>>
> >>> /*
> >>> * Check reshape again to avoid reshape happens after checking
> >>
> >>
> >> Kind regards,
> >>
> >> Paul
> >>
> >
> >
> > .
> >
>
