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Date: Fri, 21 Mar 2014 08:17:06 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Pavel Shilovsky <piastry@etersoft.ru>
Cc: Jeff Layton <jlayton@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
        linux-cifs <linux-cifs@vger.kernel.org>,
        Steve French <sfrench@samba.org>,
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        Clark Williams <williams@redhat.com>,
        "Luis Claudio R. Goncalves" <lclaudio@uudg.org>,
        Thomas Gleixner <tglx@linutronix.de>, Tejun Heo <tj@kernel.org>,
        uobergfe@redhat.com
Subject: Re: [RFC PATCH] cifs: Fix possible deadlock with cifs and work
 queues
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On Fri, 21 Mar 2014 12:32:12 +0400
Pavel Shilovsky <piastry@etersoft.ru> wrote:


> Read and write codepaths both obtain lock_sem for read and then wait
> for cifsiod_wq to complete and release lock_sem. They don't do any
> lock_sem operations inside their work task queued to cifsiod_wq. But
> oplock code can obtain/release lock_sem in its work task. So, that's
> why I agree with Jeff and suggest to move the oplock code to a
> different work queue (cifsioopd_wq?) but leave read and write
> codepaths use cifsiod_wq.

OK, how about I submit a second patch that moves the reader and writer
to its own "safe" workqueue?

-- Steve