Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755017Ab0GUMLq (ORCPT ); Wed, 21 Jul 2010 08:11:46 -0400 Received: from cantor.suse.de ([195.135.220.2]:49501 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750972Ab0GUMLp (ORCPT ); Wed, 21 Jul 2010 08:11:45 -0400 Date: Wed, 21 Jul 2010 14:11:17 +0200 From: Jan Kara To: Stephen Rothwell Cc: Andrew Morton , Dave Chinner , Al Viro , linux-next@vger.kernel.org, LKML , Christoph Hellwig , Jens Axboe , Jan Kara Subject: Re: linux-next: OOPS at boot time Message-ID: <20100721121116.GD3447@quack.suse.cz> References: <20100720164145.e06242b3.sfr@canb.auug.org.au> <20100720033656.0ce6356f.akpm@linux-foundation.org> <20100720224525.GO32635@dastard> <20100720174424.12a4bf64.akpm@linux-foundation.org> <20100721052007.GT32635@dastard> <20100721002907.639802cd.akpm@linux-foundation.org> <20100721174809.4781c244.sfr@canb.auug.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100721174809.4781c244.sfr@canb.auug.org.au> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2392 Lines: 56 On Wed 21-07-10 17:48:09, Stephen Rothwell wrote: > On Wed, 21 Jul 2010 00:29:07 -0700 Andrew Morton wrote: > > > > On Wed, 21 Jul 2010 15:20:07 +1000 Dave Chinner wrote: > > > > > > and they were dirtied within dquot_free_space(). > > > > > > AFAICT dquot_free_space() is called deep in the guts of > > > ext3_truncate() via dquot_free_block(), which is called directly > > > before end_writeback(). That should overwrite any state changes made > > > inside ext3_truncate. I wonder if iput_final() is racing with > > > something else here? > > > > > > > This isn't a race. I type `make' and the warnings spew out at hundreds > > per second - every unlink, I'd say. > > Bisected to: > > commit 8bfe4a06746e5f03c02afe3ceb97b5364c099f63 > Author: Al Viro > Date: Sun Jun 6 07:08:19 2010 -0400 > > convert ext3 to ->evict_inode() > > Signed-off-by: Al Viro Thanks for bisecting this. The patch series indeed seems to uncover some discrepancies. Ext3 has always dirtied inode in it's ->delete_inode method (via quota code). But previously clear_inode() just overwrote the state with I_CLEAR and thus we never saw the BUG_ON. After Al's patches, i_state is set in end_writeback() which happens earlier. In particular it happens before ext3_free_inode() which dirties the inode through quota code while freeing xattrs - they are accounted in i_blocks, so i_blocks are updated during freeing and inode is dirtied. Actually, ext3_mark_inode_dirty() called during each mark_inode_dirty() call writes the inode state to the journal so the dirty flag in the inode state is in fact stale and overwriting it with I_CLEAR never mattered. In this sense, the BUG_ON triggered is a false positive. But I believe this is a separate story. I'm not sure how to really fix this. It seems a bit premature to me to mark inode as I_CLEAR before the filesystem is actually done with it. So maybe the line inode->i_state = I_FREEING | I_CLEAR; should be moved to evict() fuction? Honza -- Jan Kara SUSE Labs, CR -- 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/