From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C0368C3DA6F for ; Fri, 25 Aug 2023 09:10:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244225AbjHYJKS (ORCPT ); Fri, 25 Aug 2023 05:10:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244218AbjHYJKK (ORCPT ); Fri, 25 Aug 2023 05:10:10 -0400 X-Greylist: delayed 2259 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 25 Aug 2023 02:10:08 PDT Received: from mxhk.zte.com.cn (mxhk.zte.com.cn [63.216.63.35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 025D31BF2; Fri, 25 Aug 2023 02:10:07 -0700 (PDT) Received: from mse-fl2.zte.com.cn (unknown [10.5.228.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mxhk.zte.com.cn (FangMail) with ESMTPS id 4RXDgG5J5jz4xPYg; Fri, 25 Aug 2023 17:10:02 +0800 (CST) Received: from szxlzmapp03.zte.com.cn ([10.5.231.207]) by mse-fl2.zte.com.cn with SMTP id 37P99IOX020744; Fri, 25 Aug 2023 17:09:18 +0800 (+08) (envelope-from cheng.lin130@zte.com.cn) Received: from mapi (szxlzmapp03[null]) by mapi (Zmail) with MAPI id mid14; Fri, 25 Aug 2023 17:09:20 +0800 (CST) Date: Fri, 25 Aug 2023 17:09:20 +0800 (CST) X-Zmail-TransId: 2b0564e86fc074a-0da49 X-Mailer: Zmail v1.0 Message-ID: <202308251709208292077@zte.com.cn> In-Reply-To: References: 202308241543526473806@zte.com.cn,ZOfhoLql0TYiD5JW@dread.disaster.area Mime-Version: 1.0 From: To: Cc: , , , , , Subject: =?UTF-8?B?UmU6IFtQQVRDSF0geGZzOiBpbnRyb2R1Y2UgcHJvdGVjdGlvbiBmb3IgZHJvcCBubGluaw==?= Content-Type: text/plain; charset="UTF-8" X-MAIL: mse-fl2.zte.com.cn 37P99IOX020744 X-Fangmail-Gw-Spam-Type: 0 X-Fangmail-Anti-Spam-Filtered: true X-Fangmail-MID-QID: 64E86FEA.002/4RXDgG5J5jz4xPYg Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org > On Thu, Aug 24, 2023 at 03:43:52PM +0800, cheng.lin130@zte.com.cn wrote: >> From: Cheng Lin >> An dir nlinks overflow which down form 0 to 0xffffffff, cause the >> directory to become unusable until the next xfs_repair run. > Hmmm. How does this ever happen? > IMO, if it does happen, we need to fix whatever bug that causes it > to happen, not issue a warning and do nothing about the fact we > just hit a corrupt inode state... Yes, I'm very agree with your opinion. But I don't know how it happened, and how to reproduce it. >> Introduce protection for drop nlink to reduce the impact of this. >> And produce a warning for directory nlink error during remove. >> >> Signed-off-by: Cheng Lin >> --- >> fs/xfs/xfs_inode.c | 16 +++++++++++++++- >> 1 file changed, 15 insertions(+), 1 deletion(-) >> >> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c >> index 9e62cc5..536dbe4 100644 >> --- a/fs/xfs/xfs_inode.c >> +++ b/fs/xfs/xfs_inode.c >> @@ -919,6 +919,15 @@ STATIC int xfs_iunlink_remove(struct xfs_trans *tp, struct xfs_perag *pag, >> xfs_trans_t *tp, >> xfs_inode_t *ip) >> { >> + xfs_mount_t *mp; >> + >> + if (VFS_I(ip)->i_nlink == 0) { >> + mp = ip->i_mount; >> + xfs_warn(mp, "%s: Deleting inode %llu with no links.", >> + __func__, ip->i_ino); >> + return 0; >> + } > This is obviously incorrect - whiteout inodes (RENAME_WHITEOUT) have an > i_nlink of zero when they are removed from the unlinked list. As do > O_TMPFILE inodes - when they are linked into the filesystem, we > explicitly check for i_nlink being zero before calling > xfs_iunlink_remove(). I am not familiar with the above process. You means there is such a scenario, even if it is (i_nlink==0), it still needs to run drop_nlink() in xfs_droplink()? But this will cause i_nlink to underflow to 0xffffffff. >> + >> xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG); >> >> drop_nlink(VFS_I(ip)); > Wait a second - this code doesn't match an upstream kernel. What > kernel did you make this patch against? It's kernel mainline linux-6.5-rc7 Thanks. > -Dave. > -- > Dave Chinner > david@fromorbit.com