From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f43.google.com ([74.125.82.43]:34007 "EHLO mail-wg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752302AbbFCJ32 (ORCPT ); Wed, 3 Jun 2015 05:29:28 -0400 Message-ID: <556EC8F4.7030507@suse.cz> Date: Wed, 03 Jun 2015 11:29:24 +0200 From: Jiri Slaby MIME-Version: 1.0 To: gregkh@linuxfoundation.org, dmarkh@cfl.rr.com, JBottomley@Odin.com, hare@suse.de CC: stable@vger.kernel.org, stable-commits@vger.kernel.org, Geert Uytterhoeven Subject: Re: Patch "sd: Disable support for 256 byte/sector disks" has been added to the 4.0-stable tree References: <14333133244847@kroah.com> In-Reply-To: <14333133244847@kroah.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On 06/03/2015, 08:35 AM, gregkh@linuxfoundation.org wrote: > From 74856fbf441929918c49ff262ace9835048e4e6a Mon Sep 17 00:00:00 2001 > From: Mark Hounschell > Date: Wed, 13 May 2015 10:49:09 +0200 > Subject: sd: Disable support for 256 byte/sector disks > > From: Mark Hounschell > > commit 74856fbf441929918c49ff262ace9835048e4e6a upstream. > > 256 bytes per sector support has been broken since 2.6.X, > and no-one stepped up to fix this. > So disable support for it. > > Signed-off-by: Mark Hounschell > Signed-off-by: Hannes Reinecke > Signed-off-by: James Bottomley > Signed-off-by: Greg Kroah-Hartman > > --- > drivers/scsi/sd.c | 19 +++++-------------- > 1 file changed, 5 insertions(+), 14 deletions(-) > > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -1624,6 +1624,7 @@ static unsigned int sd_completed_bytes(s > { > u64 start_lba = blk_rq_pos(scmd->request); > u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512); > + u64 factor = scmd->device->sector_size / 512; > u64 bad_lba; > int info_valid; > /* > @@ -1645,16 +1646,9 @@ static unsigned int sd_completed_bytes(s > if (scsi_bufflen(scmd) <= scmd->device->sector_size) > return 0; > > - if (scmd->device->sector_size < 512) { > - /* only legitimate sector_size here is 256 */ > - start_lba <<= 1; > - end_lba <<= 1; > - } else { > - /* be careful ... don't want any overflows */ > - unsigned int factor = scmd->device->sector_size / 512; > - do_div(start_lba, factor); > - do_div(end_lba, factor); > - } Hmm, you do 'unsigned int' -> 'u64' switch of factor type here. But this commit: commit ef80d1e18b014af08741cf688e3fdda1fb71363f Author: Geert Uytterhoeven Date: Mon Nov 4 10:21:05 2013 +0100 [SCSI] sd: Do not call do_div() with a 64-bit divisor did the switch in the opposite direction deliberately. So why did you do the change, given sector_size is uint? thanks, -- js suse labs