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From: Miklos Szeredi <miklos@szeredi.hu>
To: fuse-devel <fuse-devel@lists.sourceforge.net>
Cc: linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [fuse-devel] fuse: trying to steal weird page
Date: Tue, 26 Feb 2019 14:30:01 +0100	[thread overview]
Message-ID: <CAJfpegu-QU-A0HORYjcrx3fM5FKGUop0x6k10A526ZV=p0CEuw@mail.gmail.com> (raw)
In-Reply-To: <CAJfpeguCJnGrzCtHREq9d5uV-=g9JBmrX_c===giZB7FxWCcgw@mail.gmail.com>

On Tue, Feb 26, 2019 at 1:57 PM Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> On Mon, Feb 25, 2019 at 10:41 PM Nikolaus Rath <Nikolaus@rath.org> wrote:
> >
> > On Feb 12 2019, Nikolaus Rath <Nikolaus@rath.org> wrote:
> > > On Feb 12 2019, Miklos Szeredi <miklos@szeredi.hu> wrote:
> > >> On Sun, Feb 10, 2019 at 11:05 PM Nikolaus Rath <Nikolaus@rath.org> wrote:
> > >>
> > >>> Bad news. I can now reliably reproduce the issue again.
> > >>
> > >> A reliable reproducer is always good news.   Are the messages exactly
> > >> the same as last time (value of flags, etc)?
> > >
> > > The flags, count, mapcount and mapping values are always the same. The
> > > page and index is varying. So the general format is:
> > >
> > > [ 2562.773181] fuse: trying to steal weird page
> > > [ 2562.773187] page=<something> index=<something>
> > > flags=17ffffc00000ad, count=1, mapcount=0, mapping= (null)
> >
> > Is there anything else I can do to help debugging this?
>
> Could you please try the attached patch?

Looking more, it's very unlikely to help.  remove_mapping() should
already ensure that the page count is 1.

I think this bug report needs to be forwarded to the
<linux-mm@kvack.org> mailing list as this appears to be  a race
somewhere in the memory management subsystem and fuse is only making
it visible due to its sanity checking in the page stealing code.

Thanks,
Miklos

  reply	other threads:[~2019-02-26 13:30 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-26 21:43 Nikolaus Rath
2019-01-07  8:28 ` [fuse-devel] " Miklos Szeredi
2019-01-07 21:05   ` Nikolaus Rath
2019-01-08  8:27     ` Miklos Szeredi
2019-01-08 10:35       ` Nikolaus Rath
2019-01-09  8:07         ` Miklos Szeredi
     [not found]           ` <CAJfpegtiXDgSBWN8MRubpAdJFxy95X21nO_yycCZhpvKLVePRA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-01-11 15:39             ` Nikolaus Rath
2019-01-11 15:39               ` [fuse-devel] " Nikolaus Rath
2019-02-10 22:05               ` Nikolaus Rath
2019-02-12 14:57                 ` Miklos Szeredi
2019-02-12 21:28                   ` Nikolaus Rath
2019-02-25 21:41                     ` Nikolaus Rath
2019-02-26 12:57                       ` Miklos Szeredi
2019-02-26 13:30                         ` Miklos Szeredi [this message]
2020-05-02 19:09 Nikolaus Rath
2020-05-02 19:52 ` Nikolaus Rath
2020-05-03  3:26   ` Matthew Wilcox
2020-05-03  8:43     ` [fuse-devel] " Nikolaus Rath
2020-05-03 10:27       ` Matthew Wilcox
2020-05-03 18:28         ` Gabriel Krisman Bertazi
2020-05-03 20:06           ` Matthew Wilcox
2020-05-03 20:25           ` Nikolaus Rath
2020-05-06 13:57             ` Vlastimil Babka
2020-05-03 21:34         ` Hugh Dickins
2020-05-18 12:45         ` Miklos Szeredi
2020-05-18 14:48           ` Matthew Wilcox
2020-05-18 14:58             ` Miklos Szeredi
2020-05-18 15:26               ` Matthew Wilcox

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