Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752157AbbBXI1a (ORCPT ); Tue, 24 Feb 2015 03:27:30 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:41984 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750788AbbBXI13 (ORCPT ); Tue, 24 Feb 2015 03:27:29 -0500 Date: Tue, 24 Feb 2015 00:27:25 -0800 From: Brian Norris To: Felix Fietkau Cc: Rodrigo Freire , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, =?iso-8859-1?Q?J=F6rn?= Engel , dwmw2@infradead.org, Herton Krzesinski Subject: Re: [PATCH v3 3/3] mtd: block2mtd: Removes PAGE_MASK as a index to partition size Message-ID: <20150224082725.GG24441@norris-Latitude-E6410> References: <1444809468.34812041.1410206680931.JavaMail.zimbra@redhat.com> <20140909170231.GA14429@logfs.org> <1807144344.40128259.1410985683342.JavaMail.zimbra@redhat.com> <20141105202303.GN23619@ld-irv-0074> <2086372266.7454667.1415535533979.JavaMail.zimbra@redhat.com> <1874445287.7454806.1415535792984.JavaMail.zimbra@redhat.com> <20141126072147.GO3212@norris-Latitude-E6410> <1417070032.4547583.1417007972343.JavaMail.zimbra@redhat.com> <20150224080752.GF24441@norris-Latitude-E6410> <54EC344F.3050709@openwrt.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <54EC344F.3050709@openwrt.org> 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 Content-Length: 2213 Lines: 53 On Tue, Feb 24, 2015 at 09:20:31PM +1300, Felix Fietkau wrote: > On 2015-02-24 21:07, Brian Norris wrote: > > On Wed, Nov 26, 2014 at 08:19:32AM -0500, Rodrigo Freire wrote: > >> From: "Brian Norris" > >> Sent: Wednesday, November 26, 2014 5:21:47 AM > >> Subject: Re: [PATCH v3 3/3] mtd: block2mtd: Removes PAGE_MASK as a index to > >> partition size > >> > >> > On Sun, Nov 09, 2014 at 07:23:12AM -0500, Rodrigo Freire wrote: > >> > > - dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK; > >> > > + dev->mtd.size = dev->blkdev->bd_inode->i_size & ~(erase_size - 1); > >> > >> > You never guaranteed that erase_size is a power of two, so this doesn't > >> > necessarily mask the way you'd like... > >> > >> > But also, why is this even necessary? I see that we should already have > >> > errored out if this was actually significant, since we have above: > >> > >> > if ((long)dev->blkdev->bd_inode->i_size % erase_size) { > >> > pr_err("erasesize must be a divisor of device size\n"); > >> > goto err_free_block2mtd; > >> > } > >> > >> Hello Brian, and thanks for the review. > >> > >> Honestly, I'd leave that untouched, but J?rn pointed that it could be a issue at https://lkml.org/lkml/2014/9/9/680 > >> > >> I'd happily let it go without this patch 3, unless J?rg wants to state otherwise. > > > > OK let's drop this patch from the series. At best, we could just do > > something like this instead: > > > > - dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK; > > + dev->mtd.size = dev->blkdev->bd_inode->i_size; > > > > But that's really just an unnecessary change. > If I remember correctly, it was problematic to have a dev->mtd.size > value which is not a multiple of the erase size. I think that was the > reason for patch 3. The what's this for? if ((long)dev->blkdev->bd_inode->i_size % erase_size) { pr_err("erasesize must be a divisor of device size\n"); goto err_free_block2mtd; } Brian -- 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/