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 2707EC433FE for ; Fri, 14 Oct 2022 03:49:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229818AbiJNDt6 (ORCPT ); Thu, 13 Oct 2022 23:49:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229769AbiJNDt5 (ORCPT ); Thu, 13 Oct 2022 23:49:57 -0400 Received: from mail105.syd.optusnet.com.au (mail105.syd.optusnet.com.au [211.29.132.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 269F127FEE for ; Thu, 13 Oct 2022 20:49:53 -0700 (PDT) Received: from dread.disaster.area (pa49-181-106-210.pa.nsw.optusnet.com.au [49.181.106.210]) by mail105.syd.optusnet.com.au (Postfix) with ESMTPS id AA6491101746; Fri, 14 Oct 2022 14:49:52 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1ojBhm-001jjW-0T; Fri, 14 Oct 2022 14:49:50 +1100 Date: Fri, 14 Oct 2022 14:49:50 +1100 From: Dave Chinner To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 1/2] xfs: load rtbitmap and rtsummary extent mapping btrees at mount time Message-ID: <20221014034950.GJ3600936@dread.disaster.area> References: <166473480232.1083697.18352887736798889545.stgit@magnolia> <166473480249.1083697.13081552727850377113.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <166473480249.1083697.13081552727850377113.stgit@magnolia> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.4 cv=e9dl9Yl/ c=1 sm=1 tr=0 ts=6348dc60 a=j6JUzzrSC7wlfFge/rmVbg==:117 a=j6JUzzrSC7wlfFge/rmVbg==:17 a=kj9zAlcOel0A:10 a=Qawa6l4ZSaYA:10 a=VwQbUJbxAAAA:8 a=20KFwNOVAAAA:8 a=7-415B0cAAAA:8 a=EDEgQ8aR-Fp8ck5jjCkA:9 a=CjuIK1q_8ugA:10 a=AjGcO6oz07-iQ99wixmX:22 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sun, Oct 02, 2022 at 11:20:02AM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > It turns out that GETFSMAP and online fsck have had a bug for years due > to their use of ILOCK_SHARED to coordinate their linear scans of the > realtime bitmap. If the bitmap file's data fork happens to be in BTREE > format and the scan occurs immediately after mounting, the incore bmbt > will not be populated, leading to ASSERTs tripping over the incorrect > inode state. Because the bitmap scans always lock bitmap buffers in > increasing order of file offset, it is appropriate for these two callers > to take a shared ILOCK to improve scalability. > > To fix this problem, load both data and attr fork state into memory when > mounting the realtime inodes. Realtime metadata files aren't supposed > to have an attr fork so the second step is likely a nop. > > On most filesystems this is unlikely since the rtbitmap data fork is > usually in extents format, but it's possible to craft a filesystem that > will by fragmenting the free space in the data section and growfsing the > rt section. > > Fixes: 4c934c7dd60c ("xfs: report realtime space information via the rtbitmap") > Also-Fixes: 46d9bfb5e706 ("xfs: cross-reference the realtime bitmap") > Signed-off-by: Darrick J. Wong > --- > fs/xfs/xfs_rtalloc.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 52 insertions(+), 4 deletions(-) Looks fine. Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com