From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752372Ab2HNOd5 (ORCPT ); Tue, 14 Aug 2012 10:33:57 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:57881 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751673Ab2HNOd4 (ORCPT ); Tue, 14 Aug 2012 10:33:56 -0400 Date: Tue, 14 Aug 2012 11:33:48 -0300 From: Herton Ronaldo Krzesinski To: Ben Hutchings Cc: Jens Axboe , Jiri Kosina , Andrew Morton , Tejun Heo , linux-kernel@vger.kernel.org, Vivek Goyal , Stanislaw Gruszka Subject: Re: [PATCH v3 3/6] floppy: avoid leaking extra reference to queue on do_floppy_init error handling Message-ID: <20120814143346.GC5277@herton-Z68MA-D2H-B3> References: <1344881787-6422-1-git-send-email-herton.krzesinski@canonical.com> <1344881787-6422-4-git-send-email-herton.krzesinski@canonical.com> <1344914439.824.178.camel@deadeye.wl.decadent.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1344914439.824.178.camel@deadeye.wl.decadent.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 14, 2012 at 04:20:39AM +0100, Ben Hutchings wrote: > It's totally ridiculous that a driver should have to do this. Any > registered disk should have the GENHD_FL_UP flag set... so why can't > genhd check it? It doesn't look like floppy is the only driver affected > by this problem, either. So I suggest the following general fix > (untested): > > --- > Subject: genhd: Make put_disk() safe for disks that have not been registered > > Since commit 9f53d2f ('block: fix __blkdev_get and add_disk race > condition'), add_disk() adds a reference to disk->queue, which is then > dropped by disk_release(). But if a disk is destroyed without being > registered through add_disk() (or if add_disk() fails at the first > hurdle) then we have a reference imbalance. > > Use the GENHD_FL_UP flag to tell whether this extra reference has been > added. Remove the incomplete workaround from the floppy driver. Indeed this is a more sane/right approach. Acked-by: Herton Ronaldo Krzesinski Just the changelog is pointing to the wrong commit as already noted by Stanislaw. > > Signed-off-by: Ben Hutchings > Cc: stable@vger.kernel.org -- []'s Herton