Re: [6.5-rc5 regression] core dump hangs (was Re: [Bug report] fstests generic/051 (on xfs) hang on latest linux v6.5-rc5+)

From: Dave Chinner
Date: Mon Jun 12 2023 - 01:50:15 EST


On Sun, Jun 11, 2023 at 10:34:29PM -0700, Linus Torvalds wrote:
> On Sun, Jun 11, 2023 at 10:16 PM Dave Chinner <david@xxxxxxxxxxxxx> wrote:
> >
> > > + /* vhost workers don't participate in core dups */
> > > + if ((current->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER)
> > > + goto out;
> > > +
> >
> > That would appear to make things worse. mkfs.xfs hung in Z state on
> > exit and never returned to the shell.
>
> Well, duh, that's because I'm a complete nincompoop who just copied
> the condition from the other cases, but those other cases were for
> testing the "this is *not* a vhost worker".
>
> Here the logic - as per the comment I added - was supposed to be "is
> this a vhost worker".
>
> So that "!=" should obviously have been a "==".

Same as without the condition - all the fsstress tasks hang in
do_coredump().

Cheers,

Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx