From: Christian Kujau <lists@nerdbynature.de>
To: David Howells <dhowells@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Anna Schumaker <anna.schumaker@netapp.com>,
Steve Dickson <steved@redhat.com>
Subject: Re: FS-Cache: Duplicate cookie detected
Date: Wed, 6 Mar 2019 09:56:17 -0800 (PST) [thread overview]
Message-ID: <alpine.DEB.2.21.999.1903060943320.1662@trent.utfs.org> (raw)
In-Reply-To: <10106.1551892803@warthog.procyon.org.uk>
On Wed, 6 Mar 2019, David Howells wrote:
> I can reproduce a slightly different problem by setting off ~6000 parallel
> processes, each reading its own individual directory of files.
Ususually I only see it shortly after mount, and only once, but I too can
reproduce it with NFStest ([0], and there's a Fedora package too) via
"nfstest_cache --server $SERVER --client `hostname`", which then produces
a couple of these messages:
FS-Cache: Duplicate cookie detected
FS-Cache: O-cookie c=000000002fcc866b [p=00000000c10c6e18 fl=222 nc=0 na=1]
FS-Cache: O-cookie d=00000000d5ed73bb n=00000000076c9150
FS-Cache: O-key=[10] '040002000801c0a80073'
FS-Cache: N-cookie c=00000000e8d5dcd4 [p=00000000c10c6e18 fl=2 nc=0 na=1]
FS-Cache: N-cookie d=00000000d5ed73bb n=00000000a54e9705
FS-Cache: N-key=[10] '040002000801c0a80073'
...and the O-key does indeed seem to resemble the server address,
somewhat:
>>> s = "040002000801c0a80073";
>>> bytes = ["".join(x) for x in zip(*[iter(s)]*2)]; bytes = [int(x, 16) for x in bytes]; print ".".join(str(x) for x in reversed(bytes))
115.0.168.192.1.8.0.2.0.4
^^^^^^^^^^^^^
Mount options on that client are:
$ mount | grep nfs4
nfs:/usr/local/src on /usr/local/src type nfs4 (ro,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.56.139,local_lock=none,addr=192.168.0.115)
...so FS-Cache ("fsc") isn't even used here. The server in that scenario
is a current Fedora 29 installation.
HTH,
Christian.
[0] http://wiki.linux-nfs.org/wiki/index.php/NFStest
>
> I also see reports like this:
>
> FS-Cache: Duplicate cookie detected
> FS-Cache: O-cookie c=00000000db33ad59 [p=000000004bc53500 fl=218 nc=0 na=0]
> FS-Cache: O-cookie d= (null) n= (null)
> FS-Cache: O-cookie o=000000006cf6db4f
> FS-Cache: O-key=[16] '0100010101000000e51fc6000323ae02'
> FS-Cache: N-cookie c=00000000791c49d0 [p=000000004bc53500 fl=2 nc=0 na=1]
> FS-Cache: N-cookie d=00000000e220fe14 n=00000000d4484489
> FS-Cache: N-key=[16] '0100010101000000e51fc6000323ae02'
>
> with no cookie def or netfs data and flags ACQUIRED, RELINQUISHED and
> INVALIDATING - which I can insert a wait for.
>
> David
--
BOFH excuse #420:
Feature was not beta tested
next prev parent reply other threads:[~2019-03-06 17:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-06 0:24 FS-Cache: Duplicate cookie detected Christian Kujau
2019-03-06 13:16 ` David Howells
2019-03-06 17:20 ` David Howells
2019-03-06 17:56 ` Christian Kujau [this message]
2019-03-08 14:49 ` David Howells
2019-03-08 17:57 ` Christian Kujau
2019-03-08 23:15 ` Christian Kujau
2019-03-08 23:25 ` Christian Kujau
2019-03-11 14:48 ` David Howells
2019-03-11 14:50 ` [PATCH 1/3] fscache: Fix cookie collision David Howells
2019-03-11 14:50 ` [PATCH 2/3] fscache: Add missing unhash David Howells
2019-03-11 14:50 ` [PATCH 3/3] fscache: Print cookie debugging information David Howells
2019-03-12 6:07 ` FS-Cache: Duplicate cookie detected Christian Kujau
2019-03-12 7:01 ` David Howells
2019-03-31 9:05 ` Christian Kujau
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