public inbox for linux-scsi@vger.kernel.org
 help / color / mirror / Atom feed
From: James Bottomley <James.Bottomley@SteelEye.com>
To: Jens Axboe <axboe@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>,
	Chris Rankin <rankincj@yahoo.com>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	SCSI Mailing List <linux-scsi@vger.kernel.org>
Subject: Re: [OOPS] 2.6.11 - NMI lockup with CFQ scheduler
Date: Thu, 07 Apr 2005 09:39:43 -0400	[thread overview]
Message-ID: <1112881183.5842.13.camel@mulgrave> (raw)
In-Reply-To: <20050407133222.GJ1847@suse.de>

On Thu, 2005-04-07 at 15:32 +0200, Jens Axboe wrote:
> I think Christophs point is that why add sdev_lock as a pointer, instead
> of just killing it? It's only used in one location, so it's not really
> that confusing (and a comment could fix that).

Because any use of sdev->request_queue->queue_lock would likely succeed
even after we've freed the device and released the queue.  If it's a
pointer and we null it after free and release, then any later use will
trigger an immediate NULL deref oops.

Since we've had so many nasty problems around refcounting, I just would
like to assure myself that we're doing everything correctly (I really
believe we are, but empirical evidence is also nice).

James



  reply	other threads:[~2005-04-07 13:39 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20050329115405.97559.qmail@web52909.mail.yahoo.com>
2005-03-29 12:03 ` [OOPS] 2.6.11 - NMI lockup with CFQ scheduler Jens Axboe
2005-04-06 16:27   ` James Bottomley
2005-04-06 17:58     ` Jens Axboe
2005-04-06 18:20       ` James Bottomley
2005-04-06 19:08         ` Jens Axboe
2005-04-06 21:09           ` James Bottomley
2005-04-07  6:49             ` Jens Axboe
2005-04-07 13:18               ` James Bottomley
2005-04-07 13:22                 ` Christoph Hellwig
2005-04-07 13:24                   ` Jens Axboe
2005-04-07 13:30                   ` James Bottomley
2005-04-07 13:32                     ` Jens Axboe
2005-04-07 13:39                       ` James Bottomley [this message]
2005-04-07 14:45                         ` Jens Axboe
2005-04-08 13:04                           ` James Bottomley
2005-04-08 13:09                             ` Jens Axboe
2005-04-07 13:24                 ` Jens Axboe
2005-03-29 12:22 Chris Rankin
2005-03-29 12:26 ` Jens Axboe
2005-04-06 12:31   ` Jens Axboe
2005-04-06 12:52     ` Arjan van de Ven
2005-04-06 12:55       ` Jens Axboe
2005-04-06 13:38         ` Tejun Heo
2005-04-06 18:01           ` Jens Axboe
2005-04-06 20:32           ` Mike Anderson

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=1112881183.5842.13.camel@mulgrave \
    --to=james.bottomley@steeleye.com \
    --cc=axboe@suse.de \
    --cc=hch@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=rankincj@yahoo.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox