Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751120AbWJLVz0 (ORCPT ); Thu, 12 Oct 2006 17:55:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751145AbWJLVz0 (ORCPT ); Thu, 12 Oct 2006 17:55:26 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:8069 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1751120AbWJLVzZ (ORCPT ); Thu, 12 Oct 2006 17:55:25 -0400 Message-ID: <452EB9C5.4000404@us.ibm.com> Date: Thu, 12 Oct 2006 14:55:17 -0700 From: Badari Pulavarty User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: Eric Sandeen CC: Andrew Morton , Jan Kara , Eric Sandeen , Dave Jones , Linux Kernel Subject: Re: 2.6.18 ext3 panic. References: <20061009225036.GC26728@redhat.com> <20061010141145.GM23622@atrey.karlin.mff.cuni.cz> <452C18A6.3070607@redhat.com> <1160519106.28299.4.camel@dyn9047017100.beaverton.ibm.com> <452C4C47.2000107@sandeen.net> <20061011103325.GC6865@atrey.karlin.mff.cuni.cz> <452CF523.5090708@sandeen.net> <20061011142205.GB24508@atrey.karlin.mff.cuni.cz> <1160589284.1447.19.camel@dyn9047017100.beaverton.ibm.com> <452DAA26.6080200@redhat.com> <20061012122820.GK9495@atrey.karlin.mff.cuni.cz> <20061012094036.e1a3f9f1.akpm@osdl.org> <452EA06F.4060701@redhat.com> In-Reply-To: <452EA06F.4060701@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1374 Lines: 42 Eric Sandeen wrote: > Andrew Morton wrote: > > >> On Thu, 12 Oct 2006 14:28:20 +0200 >> Jan Kara wrote: >> >> >> >>> Where can we call >>> journal_dirty_data() without PageLock? >>> >>> >> block_write_full_page() will unlock the page, so ext3_writepage() >> will run journal_dirty_data_fn() against an unlocked page. >> >> I haven't looked into the exact details of the race, but it should >> be addressable via jbd_lock_bh_state() or j_list_lock coverage >> > I'm testing with something like this now; seem sane? > > journal_dirty_data & journal_unmap_data both check do > jbd_lock_bh_state(bh) close to the top... journal_dirty_data_fn has checked > buffer_mapped before getting into journal_dirty_data, but that state may > change before the lock is grabbed. Similarly re-check after we drop the lock. > > This is exactly the solution I proposed earlier (to check buffer_mapped() before calling submit_bh()). But at that time, Jan pointed out that the whole handling is wrong. But if this is the only case we need to handle, I am okay with this band aid :) Thanks, Badari - 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/