[Devel] [PATCH VZ9] fs/fuse/kio: fix unwarranted warning due to flush request race

[Konstantin Khorenko]

On 10/28/25 16:13, Kui Liu wrote:
> the process_ireq_truncate() is dead code which will be removed. I'm in the progress of cleaning up the 
> kio code, and I'll submit patches removing unused code once completed.

Super, please, send us a patch removing process_ireq_truncate() and Co and i will apply the current 
patch and the future patchset as a bunch (cleanup first of course).

And please, ACK for this review is also very welcome (Lesha?).

> 
> ------------------------------------------------------------------------------------------------------
> *From:* Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
> *Sent:* 23 October 2025 11:14
> *To:* Kui Liu <kui.liu at virtuozzo.com>; devel at openvz.org <devel at openvz.org>
> *Cc:* Andrey Zaitsev <azaitsev at virtuozzo.com>
> *Subject:* Re: [Devel] [PATCH VZ9] fs/fuse/kio: fix unwarranted warning due to flush request race
> On 10/15/25 19:07, Liu Kui wrote:
>  > diff --git a/fs/fuse/kio/pcs/pcs_map.c b/fs/fuse/kio/pcs/pcs_map.c
>  > index 62b083b4947f..8baff296aaa7 100644
>  > --- a/fs/fuse/kio/pcs/pcs_map.c
>  > +++ b/fs/fuse/kio/pcs/pcs_map.c
>  > @@ -1266,23 +1266,14 @@ void pcs_map_complete(struct pcs_map_entry *m, struct pcs_ioc_getmap *omap)
>  >
>  >   /* Atomically schedule map resolve and push ireq to wait completion */
>  >   static void pcs_map_queue_resolve(struct pcs_map_entry * m, struct pcs_int_request *ireq, int 
> direction)
>  > +__releases(m->lock)
>  >   {
>  >        LIST_HEAD(l);
>  >        int ret;
>  >
>  > -     DTRACE("enter m:%p, state:%x, ireq:%p dir:%d \n", m, m->state, ireq, direction);
>  > -
>  > -     spin_lock(&m->lock);
>  > -     /* This should not happen unless aio_dio/fsync vs truncate race */
>  > -     if (m->state & PCS_MAP_DEAD) {
>  > -             spin_unlock(&m->lock);
>  > +     assert_spin_locked(&m->lock);
> 
> This will crash when pcs_map_queue_resolve() is called from
> process_ireq_truncate().
> 
> https://bitbucket.org/virtuozzocore/vzkernel.vzs/src/09103657f3bbe0b06f89337e52190aa4159882a1/fs/fuse/ 
> kio/pcs/pcs_map.c#lines-2630 <https://bitbucket.org/virtuozzocore/vzkernel.vzs/ 
> src/09103657f3bbe0b06f89337e52190aa4159882a1/fs/fuse/kio/pcs/pcs_map.c#lines-2630>
> 
> 
> 
> --
> Best regards, Pavel Tikhomirov
> Senior Software Developer, Virtuozzo.
> 
> 
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