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From:   "Kraus, Sebastian" <sebastian.kraus@tu-berlin.de>
To:     Doug Nazar <nazard@nazar.ca>
CC:     "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH v2] Re: Strange segmentation violations of rpc.gssd in
 Debian Buster
Thread-Topic: [PATCH v2] Re: Strange segmentation violations of rpc.gssd in
 Debian Buster
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Date:   Mon, 29 Jun 2020 05:39:08 +0000
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Hi Doug,
thanks very much for your patch and efforts.
I manually backported the patch to nfs-utils 1.3.4-2.5 source in Debian Bus=
ter.
I am now testing the modified build on one of my NFSv4 file servers. Looks =
promising.

One additional question: Which nfs-utils branch are your working on - steve=
d/nfs-utils.git ?

Best Sebastian

__________________
Sebastian Kraus
Team IT am Institut f=FCr Chemie
Geb=E4ude C, Stra=DFe des 17. Juni 115, Raum C7

Technische Universit=E4t Berlin
Fakult=E4t II
Institut f=FCr Chemie
Sekretariat C3
Stra=DFe des 17. Juni 135
10623 Berlin

Email: sebastian.kraus@tu-berlin.de

________________________________________
From: linux-nfs-owner@vger.kernel.org <linux-nfs-owner@vger.kernel.org> on =
behalf of Doug Nazar <nazard@nazar.ca>
Sent: Friday, June 26, 2020 23:30
To: J. Bruce Fields
Cc: Kraus, Sebastian; linux-nfs@vger.kernel.org; Steve Dickson; Olga Kornie=
vskaia
Subject: [PATCH v2] Re: Strange segmentation violations of rpc.gssd in Debi=
an Buster

On 2020-06-26 17:02, J. Bruce Fields wrote:
> Unless I'm missing something--an upcall thread could still be using this
> file descriptor.
>
> If we're particularly unlucky, we could do a new open in a moment and
> reuse this file descriptor number, and then then writes in do_downcall()
> could end up going to some other random file.
>
> I think we want these closes done by gssd_free_client() in the !refcnt
> case?

Makes sense. I was thinking more that it was an abort situation and we
shouldn't be sending any data to the kernel but re-use is definitely a
concern.

I've split it so that we are removed from the event loop in destroy()
but the close happens in free().

Doug=