Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751850AbWKFLHG (ORCPT ); Mon, 6 Nov 2006 06:07:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751975AbWKFLHG (ORCPT ); Mon, 6 Nov 2006 06:07:06 -0500 Received: from mailhub.sw.ru ([195.214.233.200]:55982 "EHLO relay.sw.ru") by vger.kernel.org with ESMTP id S1751850AbWKFLHD (ORCPT ); Mon, 6 Nov 2006 06:07:03 -0500 Message-ID: <454F16ED.7060204@sw.ru> Date: Mon, 06 Nov 2006 14:05:17 +0300 From: Vasily Averin User-Agent: Thunderbird 1.5.0.7 (X11/20060911) MIME-Version: 1.0 To: Andrew Morton , Matthew Wilcox CC: Andy Whitcroft , reiserfs-dev@namesys.com, linux-kernel@vger.kernel.org, reiserfs-list@namesys.com Subject: Re: 2.6.19-rc4-mm2 -- reiserfs umount panic References: <20061101235407.a92f94a5.akpm@osdl.org> <454B5B56.4090307@shadowen.org> <20061103110210.08169843.akpm@osdl.org> In-Reply-To: <20061103110210.08169843.akpm@osdl.org> X-Enigmail-Version: 0.94.1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3634 Lines: 80 Matthew, 4 years ago you have patched the Locking document and changed the BKL rule for remount_fs() # ChangeSet # 2003/08/21 00:28:27-07:00 akpm@osdl.org # [PATCH] update Documentation/filesystems/Locking # From: Matthew Wilcox locking rules: All may block. - BKL s_lock mount_sem -remount_fs: yes yes maybe (see below) + BKL s_lock s_umount +remount_fs: no yes maybe (see below) As far as I understand it was a misprint, de-facto BKL is required at least for reiserfs, where is a long-lived check. Also I've found that currently remount_fs() is called only from do_remount_sb(), which is called with taken BKL in all cases: - do_umount() and do_emergency_remount() acquires BKL directly; - do_remount() which called from do_mount() with taken BKL; - get_sb_single() which called from .get_sb() and should have BKL too If you have not any objections I would like to fix this issue by the patch from the following letter. thank you, Vasily Averin Andrew Morton wrote: > On Fri, 03 Nov 2006 15:08:06 +0000 > Andy Whitcroft wrote: > >> Just happened to be watching a console of a test box when it was >> performing a post job reboot and caught the following panic. This >> specific machine is a ppc64. Sadly these are not part of the job. >> >> /me considers how we could fix that. Perhaps we could just shove a >> plain reboot at the end of one of the jobs ... hmmm. >> >> -apw >> >> REISERFS: panic (device sda3): journal_begin called without kernel lock held >> kernel BUG in reiserfs_panic at fs/reiserfs/prints.c:361! >> Oops: Exception in kernel mode, sig: 5 [#1] >> SMP NR_CPUS=32 NUMA >> Modules linked in: >> NIP: C000000000125A60 LR: C000000000125A5C CTR: 00000000000D0274 >> REGS: c00000076e693640 TRAP: 0700 Not tainted (2.6.19-rc4-mm2-autokern1) >> MSR: 8000000000029032 CR: 22008424 XER: 00000000 >> TASK = c00000003fb68250[16416] 'umount' THREAD: c00000076e690000 CPU: 2 >> GPR00: C000000000125A5C C00000076E6938C0 C0000000006662E8 0000000000000050 >> GPR04: 0000000000000000 FFFFFFFFFFFFFFFF 656C206C6F636B20 68656C640D0A726E >> GPR08: 0000000000000000 C00000000054EAB8 C00000000068F810 C00000000068F808 >> GPR12: 00000000000D0274 C000000000545500 0000000000000000 0000000000000000 >> GPR16: 00000000100A7D10 00000000100A94E0 0000000010070000 0000000000000000 >> GPR20: 0000000010010000 00000000FFFFFFFF 0000000010019218 0000000000000000 >> GPR24: 0000000000000000 000000000000000A C00000076E693BC0 000000000000000A >> GPR28: C000000000518800 C00000076E693BC0 C000000000579080 C000000000518800 >> NIP [C000000000125A60] .reiserfs_panic+0x6c/0x90 >> LR [C000000000125A5C] .reiserfs_panic+0x68/0x90 >> Call Trace: >> [C00000076E6938C0] [C000000000125A5C] .reiserfs_panic+0x68/0x90 (unreliable) >> [C00000076E693940] [C000000000134A38] .reiserfs_check_lock_depth+0x30/0x48 >> [C00000076E6939C0] [C00000000013A654] .do_journal_begin_r+0x58/0x434 >> [C00000076E693AB0] [C00000000013AC54] .journal_begin+0x108/0x170 >> [C00000076E693B50] [C000000000123130] .reiserfs_remount+0x194/0x460 >> [C00000076E693C50] [C0000000000B47D0] .do_remount_sb+0x1a8/0x224 >> [C00000076E693CF0] [C0000000000D0E98] .sys_umount+0x19c/0x2a0 >> [C00000076E693E30] [C00000000000872C] syscall_exit+0x0/0x40 > > That thump you heard was the sound of > vfs-bkl-is-not-required-for-remount_fs.patch getting dropped. Thanks. - 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/