All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Howells <dhowells@redhat.com>
To: Christian Kujau <lists@nerdbynature.de>
Cc: dhowells@redhat.com, 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, 06 Mar 2019 17:20:03 +0000	[thread overview]
Message-ID: <10106.1551892803@warthog.procyon.org.uk> (raw)
In-Reply-To: <22096.1551878195@warthog.procyon.org.uk>

David Howells <dhowells@redhat.com> wrote:

> >  FS-Cache: Duplicate cookie detected
> >  FS-Cache: O-cookie c=000000009da9dbf0 [p=000000001593f904 fl=222 nc=0 na=1]
> >  FS-Cache: O-cookie d=00000000287febd9 n=00000000980c9e8a
> >  FS-Cache: O-key=[8] '020001bdc0a80064'
> >  FS-Cache: N-cookie c=00000000bfe3f869 [p=000000001593f904 fl=2 nc=0 na=1]
> >  FS-Cache: N-cookie d=00000000287febd9 n=00000000e153f178
> >  FS-Cache: N-key=[8] '020001bdc0a80064'
> 
> I've just spotted something that all these things have in common.  The old
> cookie has FSCACHE_COOKIE_RELINQUISHING set in the flags (fl=222).  I don't
> have a wait for this situation in fscache - which I should.

I take it back - 0x200 is FSCACHE_COOKIE_ACQUIRED. :-/

I can reproduce a slightly different problem by setting off ~6000 parallel
processes, each reading its own individual directory of files.

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

  parent reply	other threads:[~2019-03-06 17:20 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 [this message]
2019-03-06 17:56   ` Christian Kujau
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=10106.1551892803@warthog.procyon.org.uk \
    --to=dhowells@redhat.com \
    --cc=anna.schumaker@netapp.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lists@nerdbynature.de \
    --cc=steved@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.