From: Fengguang Wu <fengguang.wu@intel.com>
To: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>, Vivek Goyal <vgoyal@redhat.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH block/for-3.4/core] cfq: fix cfqg ref handling when BLK_CGROUP && !CFQ_GROUP_IOSCHED
Date: Fri, 16 Mar 2012 12:20:36 +0800 [thread overview]
Message-ID: <20120316042036.GA32728@localhost> (raw)
In-Reply-To: <20120315163546.GA32137@google.com>
On Thu, Mar 15, 2012 at 09:35:46AM -0700, Tejun Heo wrote:
> When BLK_CGROUP is enabled but CFQ_GROUP_IOSCHED is, cfq ends up
> calling blkg_get/put() on dummy cfqg leading to the following crash.
>
> BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0
> IP: [<ffffffff813d44d8>] cfq_init_queue+0x258/0x430
> Reported-by: Fengguang Wu <fengguang.wu@intel.com>
> Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Thanks for the quick fix!
> ---
> Yeap, forgot to test that config combination. Fengguang, can you
> please test this patch? Jens, once Fengguang confirms the fix, can
> you please apply this on top of for-3.4/core along with the pending
> stats updates?
next prev parent reply other threads:[~2012-03-16 4:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-15 9:49 NULL dereference BUG in cfq_init_queue() Fengguang Wu
2012-03-15 16:35 ` [PATCH block/for-3.4/core] cfq: fix cfqg ref handling when BLK_CGROUP && !CFQ_GROUP_IOSCHED Tejun Heo
2012-03-15 16:46 ` Vivek Goyal
2012-03-15 16:50 ` Tejun Heo
2012-03-15 17:01 ` Vivek Goyal
2012-03-15 17:18 ` Tejun Heo
2012-03-16 4:20 ` Fengguang Wu [this message]
2012-03-23 13:04 ` Jens Axboe
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=20120316042036.GA32728@localhost \
--to=fengguang.wu@intel.com \
--cc=axboe@kernel.dk \
--cc=linux-kernel@vger.kernel.org \
--cc=tj@kernel.org \
--cc=vgoyal@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.