Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932349AbdC1Lfy (ORCPT ); Tue, 28 Mar 2017 07:35:54 -0400 Received: from mail-ot0-f195.google.com ([74.125.82.195]:36624 "EHLO mail-ot0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932185AbdC1Lfw (ORCPT ); Tue, 28 Mar 2017 07:35:52 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170328095029.3500369-1-arnd@arndb.de> From: Arnd Bergmann Date: Tue, 28 Mar 2017 13:35:40 +0200 X-Google-Sender-Auth: y10lkKPDpmofB9XOiV-ineMNOYo Message-ID: Subject: Re: [PATCH] Revert "md: raid1: use bio helper in process_checks()" To: Ming Lei Cc: Shaohua Li , NeilBrown , Jens Axboe , "colyli@suse.de" , Guoqing Jiang , Mike Christie , "open list:SOFTWARE RAID (Multiple Disks) SUPPORT" , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1245 Lines: 31 On Tue, Mar 28, 2017 at 12:44 PM, Ming Lei wrote: > On Tue, Mar 28, 2017 at 5:49 PM, Arnd Bergmann wrote: >> Commit 60928a91b0b3 ("md: raid1: use bio helper in process_checks()") >> is probably correct, but I get a new compile-time warning after >> it, and have trouble understanding what it fixes: >> >> drivers/md/raid1.c: In function 'sync_request_write': >> drivers/md/raid1.c:2172:9: error: 'page_len$' may be used uninitialized in this function [-Werror=maybe-uninitialized] >> if (memcmp(page_address(ppages[j]), >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> page_address(spages[j]), >> ~~~~~~~~~~~~~~~~~~~~~~~~ >> page_len[j])) >> ~~~~~~~~~~~~ >> drivers/md/raid1.c:2160:7: note: 'page_len$' was declared here >> int page_len[RESYNC_PAGES]; >> ^~~~~~~~ >> >> This reverts it to resolve the warning. > > Please try the following patch: > > https://lkml.org/lkml/2017/3/28/126 That patch will certainly shut up the warning, but will also prevent the compiler from warning when the function gets changed in some way that actually leads to an uninitialized use of the page_len array, which is why I didn't suggest doing it that way. Arnd