ceph-devel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Howells <dhowells@redhat.com>
To: Jeff Layton <jlayton@redhat.com>
Cc: dhowells@redhat.com, linux-cachefs@redhat.com,
	Anna Schumaker <anna.schumaker@netapp.com>,
	Steve French <sfrench@samba.org>,
	Dominique Martinet <asmadeus@codewreck.org>,
	David Wysochanski <dwysocha@redhat.com>,
	linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org,
	linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org,
	v9fs-developer@lists.sourceforge.net,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 11/12] fscache: Fix fscache_cookie_put() to not deref after dec
Date: Wed, 25 Aug 2021 15:05:51 +0100	[thread overview]
Message-ID: <2030919.1629900351@warthog.procyon.org.uk> (raw)
In-Reply-To: <6370d0a74c3ceb79c53305a64ba7a982d16d34b4.camel@redhat.com>

Jeff Layton <jlayton@redhat.com> wrote:

> > fscache_cookie_put() accesses the cookie it has just put inside the
> > tracepoint that monitors the change - but this is something it's not
> > allowed to do if we didn't reduce the count to zero.
> 
> Do you mean "if the count went to zero." ?

No.  If *we* reduced the count to zero, it falls to us to destroy the object,
so we're allowed to look into it again.

If we didn't reduce the count to zero, then someone else might destroy it
before we look into it again.

David


  parent reply	other threads:[~2021-08-25 14:06 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-21 21:44 [PATCH 00/12] fscache: Some prep work for fscache rewrite David Howells
2021-06-21 21:44 ` [PATCH 01/12] fscache: Select netfs stats if fscache stats are enabled David Howells
2021-06-21 21:45 ` [PATCH 02/12] netfs: Move cookie debug ID to struct netfs_cache_resources David Howells
2021-06-21 21:45 ` [PATCH 03/12] cachefiles: Use file_inode() rather than accessing ->f_inode David Howells
2021-06-21 21:45 ` [PATCH 04/12] fscache: Add a cookie debug ID and use that in traces David Howells
2021-06-21 21:45 ` [PATCH 05/12] fscache: Procfile to display cookies David Howells
2021-06-21 21:45 ` [PATCH 06/12] fscache, cachefiles: Remove the histogram stuff David Howells
2021-06-21 21:46 ` [PATCH 07/12] fscache: Remove the object list procfile David Howells
2021-06-21 21:46 ` [PATCH 08/12] fscache: Change %p in format strings to something else David Howells
2021-06-21 21:46 ` [PATCH 09/12] cachefiles: " David Howells
2021-06-21 21:46 ` [PATCH 10/12] fscache: Fix cookie key hashing David Howells
2021-08-24 16:11   ` Jeff Layton
2021-08-25 14:04   ` David Howells
2021-06-21 21:47 ` [PATCH 11/12] fscache: Fix fscache_cookie_put() to not deref after dec David Howells
2021-08-24 14:24   ` Jeff Layton
2021-08-25 14:05   ` David Howells [this message]
2021-06-21 21:47 ` [PATCH 12/12] fscache: Use refcount_t for the cookie refcount instead of atomic_t David Howells
2021-08-24 14:25 ` [PATCH 00/12] fscache: Some prep work for fscache rewrite Jeff Layton
2021-08-27 12:31 ` [PATCH v2 04/12] fscache: Add a cookie debug ID and use that in traces David Howells
2021-08-27 12:49   ` [Linux-cachefs] " Marc Dionne

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=2030919.1629900351@warthog.procyon.org.uk \
    --to=dhowells@redhat.com \
    --cc=anna.schumaker@netapp.com \
    --cc=asmadeus@codewreck.org \
    --cc=ceph-devel@vger.kernel.org \
    --cc=dwysocha@redhat.com \
    --cc=jlayton@redhat.com \
    --cc=linux-afs@lists.infradead.org \
    --cc=linux-cachefs@redhat.com \
    --cc=linux-cifs@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=sfrench@samba.org \
    --cc=v9fs-developer@lists.sourceforge.net \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).