From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758186AbcEFK0b (ORCPT ); Fri, 6 May 2016 06:26:31 -0400 Received: from mx2.suse.de ([195.135.220.15]:45816 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751789AbcEFK03 (ORCPT ); Fri, 6 May 2016 06:26:29 -0400 Date: Fri, 6 May 2016 12:26:22 +0200 From: Johannes Thumshirn To: Jens Axboe Cc: linux-block@vger.kernel.org, Linux Kernel Mailinglist , Hannes Reinecke , Alexander Graf , Johannes Thumshirn Subject: Re: [PATCH] block: initialize hd_stuct's reference before assigning it Message-ID: <20160506102622.GA4677@c203.arch.suse.de> References: <1462282683-17664-1-git-send-email-jthumshirn@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1462282683-17664-1-git-send-email-jthumshirn@suse.de> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 03, 2016 at 03:38:03PM +0200, Johannes Thumshirn wrote: > Inititialize the hd_struct's perpcu reference before assigning the hd_struct > to the partition table list. > > This fixes a race which could be triggered using a simple partition > creation/deletion loop with virtio-blk on aarch64. > > Signed-off-by: Johannes Thumshirn > --- > block/partition-generic.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/block/partition-generic.c b/block/partition-generic.c > index 5d87019..aa5b83a 100644 > --- a/block/partition-generic.c > +++ b/block/partition-generic.c > @@ -361,6 +361,10 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, > goto out_del; > } > > + err = -ENOMEM; > + if (hd_ref_init(p)) > + goto out_free_info; > + > /* everything is up and running, commence */ > rcu_assign_pointer(ptbl->part[partno], p); > > @@ -368,8 +372,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, > if (!dev_get_uevent_suppress(ddev)) > kobject_uevent(&pdev->kobj, KOBJ_ADD); > > - if (!hd_ref_init(p)) > - return p; > + return p; > > out_free_info: > free_part_info(p); > -- > 1.8.5.2 > We've just seen that this is already fixed with b30a337ca 'block: partition: initialize percpuref before sending out KOBJ_ADD' Sorry for the noise, Johannes -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850