From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj@kernel.org>
Subject: Re: virt_blk BUG: sleeping function called from invalid context
Date: Mon, 30 Jun 2014 16:17:41 -0400
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	<20140629082637.GA23942@redhat.com> <20140629193222.GA7030@lst.de>
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To: Jens Axboe <axboe@kernel.dk>
Cc: Josh Boyer <jwboyer@fedoraproject.org>, "Michael S. Tsirkin" <mst@redhat.com>, John McCutchan <john@johnmccutchan.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, "Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>, virtualization@lists.linux-foundation.org, Robert Love <rlove@rlove.org>, Eric Paris <eparis@parisplace.org>, Brian Lane <bcl@redhat.com>, Christoph Hellwig <hch@lst.de>
List-Id: virtualization@lists.linuxfoundation.org

On Sun, Jun 29, 2014 at 02:55:36PM -0600, Jens Axboe wrote:
> > commit d911d98748018f7c8facc035ba39c30f5cce6f9c
> > Author: Tejun Heo <tj@kernel.org>
> > Date:   Wed Apr 9 11:07:31 2014 -0400
> > 
> >     kernfs: make kernfs_notify() trigger inotify events too
> > 
> > Tejun, what do you think?
> > 
> > Josh, Brian, could you try reverting that commit to see if it helps?
> 
> That definitely be a bug. If you need to block off ->bi_end_io(), just
> must punt to a worker thread.

Ugh... didn't realize we had users triggering sysfs notifications from
an atomic context.  fsnotify support requires sleepable context.
Guess I'll have to punt it to a work item. :(

Thanks.

-- 
tejun