Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965411Ab2EOCic (ORCPT ); Mon, 14 May 2012 22:38:32 -0400 Received: from mail1.windriver.com ([147.11.146.13]:53505 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965357Ab2EOCRt (ORCPT ); Mon, 14 May 2012 22:17:49 -0400 From: Paul Gortmaker To: , Subject: [34-longterm 135/179] ext3: Fix oops in ext3_try_to_allocate_with_rsv() Date: Mon, 14 May 2012 22:13:51 -0400 Message-ID: <1337048075-6132-136-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.6 In-Reply-To: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> References: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2272 Lines: 60 From: Jan Kara ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit ad95c5e9bc8b5885f94dce720137cac8fa8da4c9 upstream. Block allocation is called from two places: ext3_get_blocks_handle() and ext3_xattr_block_set(). These two callers are not necessarily synchronized because xattr code holds only xattr_sem and i_mutex, and ext3_get_blocks_handle() may hold only truncate_mutex when called from writepage() path. Block reservation code does not expect two concurrent allocations to happen to the same inode and thus assertions can be triggered or reservation structure corruption can occur. Fix the problem by taking truncate_mutex in xattr code to serialize allocations. CC: Sage Weil Reported-by: Fyodor Ustinov Signed-off-by: Jan Kara Signed-off-by: Paul Gortmaker --- fs/ext3/xattr.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/ext3/xattr.c b/fs/ext3/xattr.c index 534a94c..3a6356d 100644 --- a/fs/ext3/xattr.c +++ b/fs/ext3/xattr.c @@ -803,8 +803,16 @@ inserted: /* We need to allocate a new block */ ext3_fsblk_t goal = ext3_group_first_block_no(sb, EXT3_I(inode)->i_block_group); - ext3_fsblk_t block = ext3_new_block(handle, inode, - goal, &error); + ext3_fsblk_t block; + + /* + * Protect us agaist concurrent allocations to the + * same inode from ext3_..._writepage(). Reservation + * code does not expect racing allocations. + */ + mutex_lock(&EXT3_I(inode)->truncate_mutex); + block = ext3_new_block(handle, inode, goal, &error); + mutex_unlock(&EXT3_I(inode)->truncate_mutex); if (error) goto cleanup; ea_idebug(inode, "creating block %d", block); -- 1.7.9.6 -- 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/