Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758899AbYHUUNY (ORCPT ); Thu, 21 Aug 2008 16:13:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754023AbYHUUNO (ORCPT ); Thu, 21 Aug 2008 16:13:14 -0400 Received: from gw.goop.org ([64.81.55.164]:58422 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754210AbYHUUNO (ORCPT ); Thu, 21 Aug 2008 16:13:14 -0400 Message-ID: <48ADCC54.1000907@goop.org> Date: Thu, 21 Aug 2008 13:13:08 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Alex Nixon CC: Jeremy Fitzhardinge , Linux Kernel Mailing List , Jens Axboe Subject: Re: [PATCH] Xen: Fix warning when hot-unplugging virtual block devices References: <48AD5373.201@citrix.com> In-Reply-To: <48AD5373.201@citrix.com> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1920 Lines: 55 Alex Nixon wrote: > From: Alex Nixon > Date: Thu, 21 Aug 2008 12:30:54 +0100 > Subject: [PATCH] Xen: Fix warning when hot-unplugging virtual block devices > > WARNING: at kernel/softirq.c:136 local_bh_enable+0x3f/0x8a() > > del_gendisk needs IRQs enabled, as the code path eventually reaches local_bh_enable. > blk_stop_queue needs them disabled - so do so temporarily. > > It shouldn't matter if an interrupt comes in whilst blkif_io_lock is held, as it will block on the lock. Upon acquisition, it'll realise the device is down and exit cleanly. > > Signed-off-by: Alex Nixon > Acked-by: Jeremy Fitzhardinge Send a clean copy to Jens with my ack. J > --- > drivers/block/xen-blkfront.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > index d5e7532..95cee2c 100644 > --- a/drivers/block/xen-blkfront.c > +++ b/drivers/block/xen-blkfront.c > @@ -899,16 +899,18 @@ static void blkfront_closing(struct xenbus_device *dev) > if (info->rq == NULL) > goto out; > > - spin_lock_irqsave(&blkif_io_lock, flags); > + spin_lock(&blkif_io_lock); > > del_gendisk(info->gd); > > + local_irq_save(flags); > /* No more blkif_request(). */ > blk_stop_queue(info->rq); > + local_irq_restore(flags); > > /* No more gnttab callback work. */ > gnttab_cancel_free_callback(&info->callback); > - spin_unlock_irqrestore(&blkif_io_lock, flags); > + spin_unlock(&blkif_io_lock); > > /* Flush gnttab callback work. Must be done with no locks held. */ > flush_scheduled_work(); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/