Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422770AbWJLHAu (ORCPT ); Thu, 12 Oct 2006 03:00:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422773AbWJLHAu (ORCPT ); Thu, 12 Oct 2006 03:00:50 -0400 Received: from smtp103.mail.mud.yahoo.com ([209.191.85.213]:22170 "HELO smtp103.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1422770AbWJLHAt (ORCPT ); Thu, 12 Oct 2006 03:00:49 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=qrhgqfWXQ0UMljmW2Lv0s62UtZzo9V0SRMZ3Kn4pck1M+BslCYLBrm20pgSoxzexIcs0DJRZm2Lw0b9lvagSjQgD4JiKPSljRWzDprRREtwh+EZ8PmvB0twFL8fxsS4uXhbyLAJdyIa5giCVr3amr4Y+ITRAW6tV5FrPl1RIGFc= ; Message-ID: <452DE82F.3080803@yahoo.com.au> Date: Thu, 12 Oct 2006 17:01:03 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Andrew Morton CC: Dmitriy Monakhov , Linux Kernel , Linux Memory Management , devel@openvz.org, ext2-devel@lists.sourceforge.net, Andrey Savochkin Subject: Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction References: <87mz82vzy1.fsf@sw.ru> <20061011234330.efae4265.akpm@osdl.org> In-Reply-To: <20061011234330.efae4265.akpm@osdl.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1141 Lines: 27 Andrew Morton wrote: > On Thu, 12 Oct 2006 09:57:26 +0400 > Dmitriy Monakhov wrote: > > >>While reading Andrew's generic_file_buffered_write patches i've remembered >>one more EXT3 issue.journal_start() in prepare_write() causes different ranking >>violations if copy_from_user() triggers a page fault. It could cause >>GFP_FS allocation, re-entering into ext3 code possibly with a different >>superblock and journal, ranking violation of journalling serialization >>and mmap_sem and page lock and all other kinds of funny consequences. > > > With the stuff Nick and I are looking at, we won't take pagefaults inside > prepare_write()/commit_write() any more. Yep. Because the page is locked, it is too much to deal with even without a filesystem in the picture. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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/