From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754214AbcGED14 (ORCPT ); Mon, 4 Jul 2016 23:27:56 -0400 Received: from mail-wm0-f43.google.com ([74.125.82.43]:38072 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751589AbcGED1y (ORCPT ); Mon, 4 Jul 2016 23:27:54 -0400 MIME-Version: 1.0 In-Reply-To: <20160704142938.GB29557@thunk.org> References: <1467285150-15977-1-git-send-email-pranjas@gmail.com> <1467285150-15977-2-git-send-email-pranjas@gmail.com> <20160704142938.GB29557@thunk.org> From: Pranay Srivastava Date: Tue, 5 Jul 2016 08:57:51 +0530 Message-ID: Subject: Re: [PATCH 1/1]ext4: Fix WARN_ON_ONCE when marking buffer dirty To: "Theodore Ts'o" , "Pranay Kr. Srivastava" , adilger.kernel@dilger.ca, linux-ext4 , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 4, 2016 at 7:59 PM, Theodore Ts'o wrote: > On Thu, Jun 30, 2016 at 02:12:30PM +0300, Pranay Kr. Srivastava wrote: >> Signed-off-by: Pranay Kr. Srivastava > > The description for why the change is being made should go in the > commit. (No need to put the description in a separate cover letter.) > I ended up rewriting the commit description as follows, to make it > much more understandable: > > ext4: Fix WARN_ON_ONCE in ext4_commit_super() > > If there are racing calls to ext4_commit_super() it's possible for > another writeback of the superblock to result in the buffer being > marked with an error after we check if the buffer is marked as > having a write error and the buffer up-to-date flag is set again. > If that happens mark_buffer_dirty() can end up throwing a > WARN_ON_ONCE. > > Fix this by moving this check to write before we call > write_buffer_dirty(), and keeping the buffer locked during this > whole sequence. > > Signed-off-by: Pranay Kr. Srivastava > Signed-off-by: Theodore Ts'o > > Note that the one-line summary needs to carry as much information as > possible so someone who is scanning the commits using git log > --oneline has a chance of understanding it. This means the high-level > *why* of the commit, not a summary of what the changes in the C code. > Also note the increased context of when the misbehaviour could occur > in the commit description, which was missing in the cover letter. > > When I'm processing patches, if I'm in a hurry, patches that require > extra work or which aren't Obviously Right, sometimes get deferred by > a few days. This patch fell in that category. > > Adding to the commit descrtipion additional context and/or > instructions for how to reproduce the problem you are trying to > remediate will often make life much easier for me, and accelerate how > quickly I'll get to your patch. > > Cheers, > > - Ted Thank you Theodore Sir. Points duly noted, I'll take care from now on while sending patches. -- ---P.K.S