Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933024Ab0GAUxU (ORCPT ); Thu, 1 Jul 2010 16:53:20 -0400 Received: from kroah.org ([198.145.64.141]:47846 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932828Ab0GAUvM (ORCPT ); Thu, 1 Jul 2010 16:51:12 -0400 X-Mailbox-Line: From gregkh@clark.site Thu Jul 1 10:34:37 2010 Message-Id: <20100701173437.597418086@clark.site> User-Agent: quilt/0.48-10.1 Date: Thu, 01 Jul 2010 10:35:14 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Eric Sandeen , "Theodore Tso" Subject: [patch 128/164] ext4: check s_log_groups_per_flex in online resize code In-Reply-To: <20100701175152.GA2135@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1944 Lines: 55 2.6.33-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Sandeen commit 42007efd569f1cf3bfb9a61da60ef6c2179508ca upstream. If groups_per_flex < 2, sbi->s_flex_groups[] doesn't get filled out, and every other access to this first tests s_log_groups_per_flex; same thing needs to happen in resize or we'll wander off into a null pointer when doing an online resize of the file system. Thanks to Christoph Biedl, who came up with the trivial testcase: # truncate --size 128M fsfile # mkfs.ext3 -F fsfile # tune2fs -O extents,uninit_bg,dir_index,flex_bg,huge_file,dir_nlink,extra_isize fsfile # e2fsck -yDf -C0 fsfile # truncate --size 132M fsfile # losetup /dev/loop0 fsfile # mount /dev/loop0 mnt # resize2fs -p /dev/loop0 https://bugzilla.kernel.org/show_bug.cgi?id=13549 Reported-by: Alessandro Polverini Test-case-by: Christoph Biedl Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/resize.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -930,7 +930,8 @@ int ext4_group_add(struct super_block *s percpu_counter_add(&sbi->s_freeinodes_counter, EXT4_INODES_PER_GROUP(sb)); - if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) { + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) && + sbi->s_log_groups_per_flex) { ext4_group_t flex_group; flex_group = ext4_flex_group(sbi, input->group); atomic_add(input->free_blocks_count, -- 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/