From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757759Ab0EEURK (ORCPT ); Wed, 5 May 2010 16:17:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47428 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755812Ab0EEURE (ORCPT ); Wed, 5 May 2010 16:17:04 -0400 Date: Wed, 5 May 2010 22:16:35 +0200 (CEST) From: John Kacur X-X-Sender: jkacur@localhost.localdomain To: OGAWA Hirofumi cc: lkml , Arnd Bergmann , Thomas Gleixner , Ingo Molnar , Frederic Weisbecker Subject: Re: [PATCH 3/6] fat: BKL ioctl pushdown In-Reply-To: <87wrvitd5c.fsf@devron.myhome.or.jp> Message-ID: References: <1273065339-21669-1-git-send-email-jkacur@redhat.com> <1273065339-21669-4-git-send-email-jkacur@redhat.com> <8739y6xrl6.fsf@devron.myhome.or.jp> <87wrvitd5c.fsf@devron.myhome.or.jp> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 6 May 2010, OGAWA Hirofumi wrote: > John Kacur writes: > > > On Thu, 6 May 2010, OGAWA Hirofumi wrote: > > > >> John Kacur writes: > >> > >> > Convert fat_generic_ioctl and fat_dir_ioctl to unlocked_ioctls > >> > and push down the bkl into those functions. > >> > >> I guess this is the part of batch ioctl conversion stuff though, those > >> ioctl of FAT don't need BKL at all. Because all of those should already > >> be protected by inode->i_mutex. > >> > >> Removing BKL and then cleanup after this patch would be almost same with > >> reverting this patch. So, could you just convert to unlocked_ioctl > >> instead? > > > > That's probably not a good idea, without a little bit more analysis, > > otherwise it's quite easy to introduce subtle bugs. > > What analysis? Who do it? I thought about removing BKL of FAT from > several years ago. I was reviewing FAT multiple times, and I'm always > testing FAT without BKL. This patch just makes explicit the hidden BKLs that FAT is already using related to ioctl. We would like to get this step done in time for the next merge window, because then we can remove that hidden source. This step is preparation for removing the BKL from the individual functions we've pushed it down into. In other words, we'll do the analysis to remove it later if you don't want to. Thanks. > > If you are going to do, could you do it instead of this patch? >