All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
To: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Joe Lawrence
	<joe.lawrence-7+ureL1bLXNBDgjK7y7TUQ@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Cgroups <cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH block/for-linus] blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t
Date: Fri, 20 Jun 2014 12:50:53 -0600	[thread overview]
Message-ID: <53A4828D.9000200@kernel.dk> (raw)
In-Reply-To: <20140620143901.GC7354-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

On 06/20/2014 08:39 AM, Vivek Goyal wrote:
> On Thu, Jun 19, 2014 at 05:42:57PM -0400, Tejun Heo wrote:
>> Hello,
>>
>> So, this patch should do.  Joe, Vivek, can one of you guys please
>> verify that the oops goes away with this patch?
> 
> Hi Tejun,
> 
> This patch seems to fix the issue for me. Tried 10 times and no crash.
> 
> So now one need to hold queue lock for getting refernce on the group
> only if caller does not already have a reference and if group has been
> looked up from some tree/queue etc. I guess only such usage seems to
> be in blkg_create() where we take a reference on parent after looking
> it up.
> 
> This patch looks good to me.
> 
> Acked-by: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

Thanks. Tejun, I'll queue this up for this cycle.

-- 
Jens Axboe

WARNING: multiple messages have this Message-ID (diff)
From: Jens Axboe <axboe@kernel.dk>
To: Vivek Goyal <vgoyal@redhat.com>, Tejun Heo <tj@kernel.org>
Cc: Joe Lawrence <joe.lawrence@stratus.com>,
	linux-kernel@vger.kernel.org, Cgroups <cgroups@vger.kernel.org>
Subject: Re: [PATCH block/for-linus] blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t
Date: Fri, 20 Jun 2014 12:50:53 -0600	[thread overview]
Message-ID: <53A4828D.9000200@kernel.dk> (raw)
In-Reply-To: <20140620143901.GC7354@redhat.com>

On 06/20/2014 08:39 AM, Vivek Goyal wrote:
> On Thu, Jun 19, 2014 at 05:42:57PM -0400, Tejun Heo wrote:
>> Hello,
>>
>> So, this patch should do.  Joe, Vivek, can one of you guys please
>> verify that the oops goes away with this patch?
> 
> Hi Tejun,
> 
> This patch seems to fix the issue for me. Tried 10 times and no crash.
> 
> So now one need to hold queue lock for getting refernce on the group
> only if caller does not already have a reference and if group has been
> looked up from some tree/queue etc. I guess only such usage seems to
> be in blkg_create() where we take a reference on parent after looking
> it up.
> 
> This patch looks good to me.
> 
> Acked-by: Vivek Goyal <vgoyal@redhat.com>

Thanks. Tejun, I'll queue this up for this cycle.

-- 
Jens Axboe


  parent reply	other threads:[~2014-06-20 18:50 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-08 22:22 docker crashes rcuos in __blkg_release_rcu Joe Lawrence
2014-06-09 17:47 ` Vivek Goyal
2014-06-09 18:27   ` Vivek Goyal
2014-06-10 18:39     ` Joe Lawrence
2014-06-10 19:14       ` Vivek Goyal
     [not found]       ` <20140610143906.0d2f35d0-ceYW5R1vr2hcrvxNGtJwk767FWEIOpWeVpNB7YpNyf8@public.gmane.org>
2014-06-11 16:32         ` Vivek Goyal
2014-06-11 16:32           ` Vivek Goyal
     [not found]           ` <20140611163229.GA12974-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-06-19 20:26             ` Tejun Heo
2014-06-19 20:26               ` Tejun Heo
     [not found]               ` <20140619202640.GA9814-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-06-19 21:42                 ` [PATCH block/for-linus] blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t Tejun Heo
2014-06-19 21:42                   ` Tejun Heo
     [not found]                   ` <20140619214257.GE9814-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-06-20 14:39                     ` Vivek Goyal
2014-06-20 14:39                       ` Vivek Goyal
     [not found]                       ` <20140620143901.GC7354-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-06-20 18:50                         ` Jens Axboe [this message]
2014-06-20 18:50                           ` Jens Axboe
2014-06-20 18:50                   ` Joe Lawrence
2014-06-20 18:50                     ` Joe Lawrence
2014-06-10 19:52 ` docker crashes rcuos in __blkg_release_rcu Christoph Lameter

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=53A4828D.9000200@kernel.dk \
    --to=axboe-tswwg44o7x1aa/9udqfwiw@public.gmane.org \
    --cc=cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=joe.lawrence-7+ureL1bLXNBDgjK7y7TUQ@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
    /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.