Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752187Ab0A1GfX (ORCPT ); Thu, 28 Jan 2010 01:35:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751595Ab0A1GfW (ORCPT ); Thu, 28 Jan 2010 01:35:22 -0500 Received: from TYO201.gate.nec.co.jp ([202.32.8.193]:46217 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751046Ab0A1GfW (ORCPT ); Thu, 28 Jan 2010 01:35:22 -0500 Message-ID: <4B612F89.7020503@ce.jp.nec.com> Date: Thu, 28 Jan 2010 15:32:41 +0900 From: "Jun'ichi Nomura" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: =?ISO-8859-1?Q?Fran=E7ois_Figarola?= , hch@infradead.org CC: device-mapper development , linux-kernel@vger.kernel.org, Neil Brown , Andrew Morton , linux-raid@vger.kernel.org, Al Viro Subject: Re: [dm-devel] [BUG] kernel 2.6.32.x hangs during boot process References: <20100122160740.6c16c22d.akpm@linux-foundation.org> <20100128134205.352044bd@notabene> In-Reply-To: <20100128134205.352044bd@notabene> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2821 Lines: 86 >> On Sat, 16 Jan 2010 10:58:30 +0100 >> Fran__ois Figarola wrote: >>> Since I've tried to boot 2.6.32.x kernel, my system hangs during the >>> boot process, and I think it could be related to the problem reported >>> earlier by Megastorage (http://lkml.org/lkml/2010/1/10/92). >>> >>> The hardware is a Dell PowerEdge 2950 which runs fine with the >>> 2.6.31.x kernel series (actually running with the latest 2.6.31.11), >>> and the system is debian etch. >>> >>> Here is the trace of the bug I've got (using netconsole) with a >>> 2.6.32.3 kernel : >>> >>> BUG: Dentry ffff880667690000{i=41a46,n=sleep} still in use (8) >>> [unmount of ext3 dm-4] >>> ------------[ cut here ]------------ >>> kernel BUG at fs/dcache.c:670! I can reproduce this when suspend/resume read-only mounted dm device. When MS_RDONLY, both freeze_bdev and thaw_bdev call deactivate_locked_super, which seems wrong. The change was introduced with the commit below: commit 4504230a71566785a05d3e6b53fa1ee071b864eb Author: Christoph Hellwig Date: Mon Aug 3 23:28:35 2009 +0200 freeze_bdev: grab active reference to frozen superblocks With the attached patch, both remount-ro and remount-rw are rejected as EBUSY on freezed device as expected. Christoph, do you think this is the right fix? -- Jun'ichi Nomura, NEC Corporation If MS_RDONLY, freeze_bdev should just up_write(s_umount) instead of deactivate_locked_super(). Also, keep sb->s_frozen consistent so that remount can check the frozen state. Signed-off-by: Jun'ichi Nomura diff --git a/fs/block_dev.c b/fs/block_dev.c index 73d6a73..600261f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -246,7 +246,9 @@ struct super_block *freeze_bdev(struct block_device *bdev) if (!sb) goto out; if (sb->s_flags & MS_RDONLY) { - deactivate_locked_super(sb); + sb->s_frozen = SB_FREEZE_TRANS; + smp_wmb(); + up_write(&sb->s_umount); mutex_unlock(&bdev->bd_fsfreeze_mutex); return sb; } @@ -307,7 +309,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) BUG_ON(sb->s_bdev != bdev); down_write(&sb->s_umount); if (sb->s_flags & MS_RDONLY) - goto out_deactivate; + goto out_unfrozen; if (sb->s_op->unfreeze_fs) { error = sb->s_op->unfreeze_fs(sb); @@ -321,11 +323,11 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) } } +out_unfrozen: sb->s_frozen = SB_UNFROZEN; smp_wmb(); wake_up(&sb->s_wait_unfrozen); -out_deactivate: if (sb) deactivate_locked_super(sb); out_unlock: -- 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/