From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932193AbbIBSmg (ORCPT ); Wed, 2 Sep 2015 14:42:36 -0400 Received: from mga11.intel.com ([192.55.52.93]:36177 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755142AbbIBSmf (ORCPT ); Wed, 2 Sep 2015 14:42:35 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,455,1437462000"; d="scan'208";a="781384390" Date: Wed, 2 Sep 2015 12:42:33 -0600 From: Ross Zwisler To: Matias =?iso-8859-1?Q?Bj=F8rling?= Cc: axboe@fb.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] null_blk: fix wrong capacity when bs is not 512 bytes Message-ID: <20150902184233.GB32255@linux.intel.com> Mail-Followup-To: Ross Zwisler , Matias =?iso-8859-1?Q?Bj=F8rling?= , axboe@fb.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <1441023451-17049-1-git-send-email-m@bjorling.me> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1441023451-17049-1-git-send-email-m@bjorling.me> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 31, 2015 at 02:17:31PM +0200, Matias Bjørling wrote: > set_capacity() sets device's capacity using 512 bytes sectors. > null_blk calculates the number of sectors by size / bs, which > set_capacity is called with. This led to null_blk exposing the > wrong number of sectors when bs is not 512 bytes. > > Signed-off-by: Matias Bjørling > --- > drivers/block/null_blk.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c > index 6f9b753..bf8f764 100644 > --- a/drivers/block/null_blk.c > +++ b/drivers/block/null_blk.c > @@ -588,8 +588,7 @@ static int null_add_dev(void) > blk_queue_physical_block_size(nullb->q, bs); > > size = gb * 1024 * 1024 * 1024ULL; > - sector_div(size, bs); > - set_capacity(disk, size); > + set_capacity(disk, size >> 9); > > disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO; > disk->major = null_major; Looks correct. Reviewed-by: Ross Zwisler