From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932216AbVHXVBw (ORCPT ); Wed, 24 Aug 2005 17:01:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932215AbVHXVBw (ORCPT ); Wed, 24 Aug 2005 17:01:52 -0400 Received: from tux06.ltc.ic.unicamp.br ([143.106.24.50]:22189 "EHLO tux06.ltc.ic.unicamp.br") by vger.kernel.org with ESMTP id S932213AbVHXVBv (ORCPT ); Wed, 24 Aug 2005 17:01:51 -0400 Date: Wed, 24 Aug 2005 18:03:25 -0300 From: Glauber de Oliveira Costa To: ext2-devel@lists.sourceforge.net, ext2resize-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, adilger@clusterfs.com, sct@redhat.com, akpm@osdl.org Subject: [PATCH] Ext3 online resizing locking issue Message-ID: <20050824210325.GK23782@br.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.8i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This simple patch provides a fix for a locking issue found in the online resizing code. The problem actually happened while trying to resize the filesystem trough the resize=xxx option in a remount. Signed-off-by: Glauber de Oliveira Costa diff -up linux-2.6.13-rc6-orig/fs/ext3/ioctl.c linux/fs/ext3/ioctl.c --- linux-2.6.13-rc6-orig/fs/ext3/ioctl.c 2005-08-24 17:48:22.000000000 -0300 +++ linux/fs/ext3/ioctl.c 2005-08-24 15:12:48.000000000 -0300 @@ -206,7 +206,9 @@ flags_err: if (get_user(n_blocks_count, (__u32 __user *)arg)) return -EFAULT; + lock_super(sb); err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count); + unlock_super(sb); journal_lock_updates(EXT3_SB(sb)->s_journal); journal_flush(EXT3_SB(sb)->s_journal); journal_unlock_updates(EXT3_SB(sb)->s_journal); Only in linux/fs/ext3: patch-mnt_resize diff -up linux-2.6.13-rc6-orig/fs/ext3/resize.c linux/fs/ext3/resize.c --- linux-2.6.13-rc6-orig/fs/ext3/resize.c 2005-08-24 17:48:22.000000000 -0300 +++ linux/fs/ext3/resize.c 2005-08-24 15:15:28.000000000 -0300 @@ -884,7 +884,9 @@ exit_put: /* Extend the filesystem to the new number of blocks specified. This entry * point is only used to extend the current filesystem to the end of the last * existing group. It can be accessed via ioctl, or by "remount,resize=" - * for emergencies (because it has no dependencies on reserved blocks). + * for emergencies (because it has no dependencies on reserved blocks). + * + * It should be called with sb->s_lock held * * If we _really_ wanted, we could use default values to call ext3_group_add() * allow the "remount" trick to work for arbitrary resizing, assuming enough @@ -959,7 +961,6 @@ int ext3_group_extend(struct super_block goto exit_put; } - lock_super(sb); if (o_blocks_count != le32_to_cpu(es->s_blocks_count)) { ext3_warning(sb, __FUNCTION__, "multiple resizers run on filesystem!\n"); @@ -978,7 +979,6 @@ int ext3_group_extend(struct super_block es->s_blocks_count = cpu_to_le32(o_blocks_count + add); ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh); sb->s_dirt = 1; - unlock_super(sb); ext3_debug("freeing blocks %ld through %ld\n", o_blocks_count, o_blocks_count + add); ext3_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks); diff -up linux-2.6.13-rc6-orig/fs/ext3/super.c linux/fs/ext3/super.c --- linux-2.6.13-rc6-orig/fs/ext3/super.c 2005-08-24 17:48:22.000000000 -0300 +++ linux/fs/ext3/super.c 2005-08-24 15:13:16.000000000 -0300 @@ -639,8 +639,8 @@ static match_table_t tokens = { {Opt_quota, "quota"}, {Opt_quota, "usrquota"}, {Opt_barrier, "barrier=%u"}, + {Opt_resize, "resize=%u"}, {Opt_err, NULL}, - {Opt_resize, "resize"}, }; static unsigned long get_sb_block(void **data)