From: Eric Sandeen Subject: [PATCH] return ENOENT from ext3_link when racing with unlink Date: Mon, 15 Jan 2007 12:18:26 -0600 Message-ID: <45ABC572.2070206@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: dmonakhov@sw.ru, alex@clusterfs.com, Al Viro Return-path: Received: from mx1.redhat.com ([66.187.233.31]:46041 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751194AbXAOSTW (ORCPT ); Mon, 15 Jan 2007 13:19:22 -0500 To: linux-kernel Mailing List , ext4 development Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org An update from the earlier thread, [PATCH] [RFC] remove ext3 inode from orphan list when link and unlink race I think this is better than the original idea of trying to handle the race; I've seen that the orphan inode list can get corrupted, but there may well be other implications of the race which haven't yet been exposed. I think it's safer to simply return -ENOENT in this race window, and avoid other potential problems. Anything wrong with this? Thanks for the comments suggesting this approach in the prior thread. Thanks, -Eric --- Return -ENOENT from ext[34]_link if we've raced with unlink and i_nlink is 0. Doing otherwise has the potential to corrupt the orphan inode list, because we'd wind up with an inode with a non-zero link count on the list, and it will never get properly cleaned up & removed from the orphan list before it is freed. Signed-off-by: Eric Sandeen Index: linux-2.6.19/fs/ext3/namei.c =================================================================== --- linux-2.6.19.orig/fs/ext3/namei.c +++ linux-2.6.19/fs/ext3/namei.c @@ -2191,6 +2191,8 @@ static int ext3_link (struct dentry * ol if (inode->i_nlink >= EXT3_LINK_MAX) return -EMLINK; + if (inode->i_nlink == 0) + return -ENOENT; retry: handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) + Index: linux-2.6.19/fs/ext4/namei.c =================================================================== --- linux-2.6.19.orig/fs/ext4/namei.c +++ linux-2.6.19/fs/ext4/namei.c @@ -2189,6 +2189,8 @@ static int ext4_link (struct dentry * ol if (inode->i_nlink >= EXT4_LINK_MAX) return -EMLINK; + if (inode->i_nlink == 0) + return -ENOENT; retry: handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +