On Fri, Jul 18, 2025 at 9:37 AM Bernd Schubert <bernd@xxxxxxxxxxx> wrote:
>
> On 7/18/25 01:26, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@xxxxxxxxxx>
> >
> > +/*
> > + * Flush all pending requests and wait for them. Only call this function when
> > + * it is no longer possible for other threads to add requests.
> > + */
> > +void fuse_flush_requests(struct fuse_conn *fc, unsigned long timeout)
>
> I wonder if this should have "abort" in its name. Because it is not a
> simple flush attempt, but also sets fc->blocked and fc->max_background.
>
> > +{
> > + unsigned long deadline;
> > +
> > + spin_lock(&fc->lock);
> > + if (!fc->connected) {
> > + spin_unlock(&fc->lock);
> > + return;
> > + }
> > +
> > + /* Push all the background requests to the queue. */
> > + spin_lock(&fc->bg_lock);
> > + fc->blocked = 0;
> > + fc->max_background = UINT_MAX;
> > + flush_bg_queue(fc);
> > + spin_unlock(&fc->bg_lock);
> > + spin_unlock(&fc->lock);
> > +
> > + /*
> > + * Wait 30s for all the events to complete or abort. Touch the
> > + * watchdog once per second so that we don't trip the hangcheck timer
> > + * while waiting for the fuse server.
> > + */
> > + deadline = jiffies + timeout;
> > + smp_mb();
> > + while (fc->connected &&
> > + (!timeout || time_before(jiffies, deadline)) &&
> > + wait_event_timeout(fc->blocked_waitq,
> > + !fc->connected || atomic_read(&fc->num_waiting) == 0,
> > + HZ) == 0)
> > + touch_softlockup_watchdog();
> > +}
> > +
> > /*
> > * Abort all requests.
> > *
> > diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
> > index 9572bdef49eecc..1734c263da3a77 100644
> > --- a/fs/fuse/inode.c
> > +++ b/fs/fuse/inode.c
> > @@ -2047,6 +2047,7 @@ void fuse_conn_destroy(struct fuse_mount *fm)
> > {
> > struct fuse_conn *fc = fm->fc;
> >
> > + fuse_flush_requests(fc, 30 * HZ);
>
> I think fc->connected should be set to 0, to avoid that new requests can
> be allocated.
fuse_abort_conn() logic is gated on "if (fc->connected)" so I think
fc->connected can only get set to 0 within fuse_abort_conn()
Thanks,
Joanne
