From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH] UBIFS: kill BKL Date: Mon, 20 Jul 2009 09:35:28 +0300 Message-ID: <4A641030.8090402@nokia.com> References: <1248000922-4065-1-git-send-email-dedekind1@gmail.com> <4A640BBF.10106@nokia.com> <4A640EBA.2070209@nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Artem Bityutskiy , "linux-fsdevel@vger.kernel.org" To: "Bityutskiy Artem (Nokia-D/Helsinki)" Return-path: Received: from smtp.nokia.com ([192.100.122.233]:49636 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752445AbZGTGfD (ORCPT ); Mon, 20 Jul 2009 02:35:03 -0400 In-Reply-To: <4A640EBA.2070209@nokia.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Bityutskiy Artem (Nokia-D/Helsinki) wrote: > On 07/20/2009 09:16 AM, Hunter Adrian (Nokia-D/Helsinki) wrote: >> Artem Bityutskiy wrote: >>> From: Artem Bityutskiy >>> >>> The BKL was pushed down from VFS to the file-systems. It used >>> to serialize mount/unmount/remount. UBIFS must be safe if several >>> file-systems are mounted/unmounted/re-mounted at the same time, >>> so kill kick the BKL out of UBIFS. >>> >>> Signed-off-by: Artem Bityutskiy >>> --- >> Looks like protection is always provided by sb->s_umount > > Err, then what would be a possible reason we would need BKL? Say if we had used BKL instead of c->umount_mutex. i.e. if we had relied on BKL in some other code to provide synchronisation with unmounting/remounting etc