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 X-Spam-Level: X-Spam-Status: No, score=-21.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AA1BC47082 for ; Thu, 3 Jun 2021 20:41:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B057613DE for ; Thu, 3 Jun 2021 20:41:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229617AbhFCUn2 (ORCPT ); Thu, 3 Jun 2021 16:43:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:43650 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229665AbhFCUn2 (ORCPT ); Thu, 3 Jun 2021 16:43:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D88C6610CB; Thu, 3 Jun 2021 20:41:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622752902; bh=CNGOX7Qtjbj220jpTBVi4b+pDrbjOMtk7JNUOMQj9yE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UkT6Qoq89/yLFhgHaqpm+IVLZFbkqwVxIBrjsFt7MvTjhQmYFpHHTt66Xr1WJ7JRT 7Qsqvf8MmmSmuZioMmI/pvlm6j/eox/k72/9Y3PuJU/hlFegmWqGz9hY9c0qF07iS9 Sm8/lSNykqe4BHvf4h9N+G/4YgmXrS0Ba7hn7Q2HZ1uvRKVPcuibnt/9k9hZmV8mix SwlD4x72ySZbxedIXQzTOTGTOGRd3fD9jcgKDRfyNqy2tirzY7biIX5lmobXzSFLeh jR11GN7EgRC0qu1X4VEr2YsodAmG4wffTFKj+gWNDZXveYJl3ZWfwiq3gPu5vybF/W e3g+hSKnzaNzg== Date: Thu, 3 Jun 2021 13:41:42 -0700 From: "Darrick J. Wong" To: Dave Chinner Cc: linux-xfs@vger.kernel.org, bfoster@redhat.com Subject: Re: [PATCH 1/3] xfs: only reset incore inode health state flags when reclaiming an inode Message-ID: <20210603204142.GY26380@locust> References: <162268995567.2724138.15163777746481739089.stgit@locust> <162268996135.2724138.14276025100886638786.stgit@locust> <20210603042107.GO664593@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210603042107.GO664593@dread.disaster.area> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Thu, Jun 03, 2021 at 02:21:07PM +1000, Dave Chinner wrote: > On Wed, Jun 02, 2021 at 08:12:41PM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > While running some fuzz tests on inode metadata, I noticed that the > > filesystem health report (as provided by xfs_spaceman) failed to report > > the file corruption even when spaceman was run immediately after running > > xfs_scrub to detect the corruption. That isn't the intended behavior; > > one ought to be able to run scrub to detect errors in the ondisk > > metadata and be able to access to those reports for some time after the > > scrub. > > > > After running the same sequence through an instrumented kernel, I > > discovered the reason why -- scrub igets the file, scans it, marks it > > sick, and ireleases the inode. When the VFS lets go of the incore > > inode, it moves to RECLAIMABLE state. If spaceman igets the incore > > inode before it moves to RECLAIM state, iget reinitializes the VFS > > state, clears the sick and checked masks, and hands back the inode. At > > this point, the caller has the exact same incore inode, but with all the > > health state erased. > > > > In other words, we're erasing the incore inode's health state flags when > > we've decided NOT to sever the link between the incore inode and the > > ondisk inode. This is wrong, so we need to remove the lines that zero > > the fields from xfs_iget_cache_hit. > > > > As a precaution, we add the same lines into xfs_reclaim_inode just after > > we sever the link between incore and ondisk inode. Strictly speaking > > this isn't necessary because once an inode has gone through reclaim it > > must go through xfs_inode_alloc (which also zeroes the state) and > > xfs_iget is careful to check for mismatches between the inode it pulls > > out of the radix tree and the one it wants. > > > > Fixes: 6772c1f11206 ("xfs: track metadata health status") > > Signed-off-by: Darrick J. Wong > > --- > > fs/xfs/xfs_icache.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > Looks fine. > > Reviewed-by: Dave Chinner > > Though I do wonder how long such state will hang around, because > once the inode is IRECLAIMABLE and clean it is only a matter of > seconds before the background inode reclaimer will free it... A future patchset will add the ability to make the per-AG health status remember that we were forced to reclaim a sick inode: https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=indirect-health-reporting This series used to be the "fixes first" part of that code, but since it directly intersects with the deferred inactivation changes, I moved it up to try to fix the problem sooner than later. Anyway, thanks for the review. --D > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com