Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161220AbWJLGnj (ORCPT ); Thu, 12 Oct 2006 02:43:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161219AbWJLGnj (ORCPT ); Thu, 12 Oct 2006 02:43:39 -0400 Received: from smtp.osdl.org ([65.172.181.4]:36021 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1161220AbWJLGnj (ORCPT ); Thu, 12 Oct 2006 02:43:39 -0400 Date: Wed, 11 Oct 2006 23:43:30 -0700 From: Andrew Morton To: Dmitriy Monakhov Cc: Linux Kernel , Linux Memory Management , , ext2-devel@lists.sourceforge.net, Andrey Savochkin Subject: Re: [RFC][PATCH] EXT3: problem with page fault inside a transaction Message-Id: <20061011234330.efae4265.akpm@osdl.org> In-Reply-To: <87mz82vzy1.fsf@sw.ru> References: <87mz82vzy1.fsf@sw.ru> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 24 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. > Our customers complain about this issue. Really? How often? What on earth are they doing to trigger this? writev() without the 2.6.18 writev() bugfix? - 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/