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 6246EC43334 for ; Thu, 7 Jul 2022 18:22:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235809AbiGGSWR (ORCPT ); Thu, 7 Jul 2022 14:22:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235666AbiGGSWR (ORCPT ); Thu, 7 Jul 2022 14:22:17 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56941564F3; Thu, 7 Jul 2022 11:22:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E7BB2621C3; Thu, 7 Jul 2022 18:22:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51007C3411E; Thu, 7 Jul 2022 18:22:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657218135; bh=E9ulP8AEVSazaD914gKMcs4HYYzIrNXsKh5tRugvTJQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ndSPaf09Dhs+NBcHll78r/E/Ndf4BbIyHduO6990EK9uFUfoo2OAcpKIn4FscA3ea 1bq7fSqop7Ats9vfArmhGLEWg0UG6DoOBTFYuVASQ3tSVXydI8WQMI1wcll2VMrDNH lF6PX54zlpVM5sllqsC/WB6jfzreKNN8hUaBaikHSOP+BV0Fdq0tBWTEgdbg61NPDb F6Yln9xK1yTecQe2/qHSsQGEgM+W5TNuLQkPT/9skIR8fMYGriBh6QkYHvnvxFhtdt UuptKGzuch3eeWEeQab+9FaI/H4p67Yiv1vYKjmMbMF2ETfLgfcOeZlLk/pxyAImgN WNvWcqOL6+Zyw== Date: Thu, 7 Jul 2022 11:22:14 -0700 From: "Darrick J. Wong" To: Zorro Lang Cc: linux-xfs@vger.kernel.org, fstests@vger.kernel.org Subject: Re: [PATCH 1/2] xfs: make sure that we handle empty xattr leaf blocks ok Message-ID: References: <165705854325.2821854.10317059026052442189.stgit@magnolia> <165705854877.2821854.7070105861462675249.stgit@magnolia> <20220707120639.qoqsfcwtmdyl5duv@zlang-mailbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220707120639.qoqsfcwtmdyl5duv@zlang-mailbox> Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Thu, Jul 07, 2022 at 08:06:39PM +0800, Zorro Lang wrote: > On Tue, Jul 05, 2022 at 03:02:28PM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > Make sure that the kernel can handle empty xattr leaf blocks properly, > > since we've screwed this up enough times. > > > > Signed-off-by: Darrick J. Wong > > --- > > tests/xfs/845 | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 131 insertions(+) > > create mode 100755 tests/xfs/845 > > > > > > diff --git a/tests/xfs/845 b/tests/xfs/845 > > new file mode 100755 > > index 00000000..4a846e57 > > --- /dev/null > > +++ b/tests/xfs/845 > > @@ -0,0 +1,131 @@ > > +#! /bin/bash > > +# SPDX-License-Identifier: GPL-2.0 > > +# Copyright (c) 2022 Oracle. All Rights Reserved. > > +# > > +# FS QA Test 845 > > +# > > +# Make sure that XFS can handle empty leaf xattr blocks correctly. These > > +# blocks can appear in files as a result of system crashes in the middle of > > +# xattr operations, which means that we /must/ handle them gracefully. > > +# Check that read and write verifiers won't trip, that the get/list/setxattr > > +# operations don't stumble over them, and that xfs_repair will offer to remove > > +# the entire xattr fork if the root xattr leaf block is empty. > > +# > > +# Regression test for kernel commit: > > +# > > +# af866926d865 ("xfs: empty xattr leaf header blocks are not corruption") > > +# > > +. ./common/preamble > > +_begin_fstest auto quick attr > > + > > +# Override the default cleanup function. > > +# _cleanup() > > +# { > > +# cd / > > +# rm -r -f $tmp.* > > +# } > > Remove this part directly? Ok. > > + > > +# Import common functions. > > +. ./common/filter > > +. ./common/attr > > + > > +# real QA test starts here > > + > > +# Modify as appropriate. > ^^ > This comment is useless Oops, will delete. > > +_supported_fs xfs > > +_require_scratch > > +_fixed_by_kernel_commit af866926d865 "xfs: empty xattr leaf header blocks are not corruption" > > + > > +_scratch_mkfs_xfs | _filter_mkfs >$seqres.full 2>$tmp.mkfs > > +cat $tmp.mkfs >> $seqres.full > > +source $tmp.mkfs > > +_scratch_mount > > + > > +$XFS_IO_PROG -f -c 'pwrite -S 0x58 0 64k' $SCRATCH_MNT/largefile >> $seqres.full > > +$XFS_IO_PROG -f -c "pwrite -S 0x58 0 $isize" $SCRATCH_MNT/smallfile >> $seqres.full > > + > > +smallfile_md5=$(md5sum < $SCRATCH_MNT/smallfile) > > +largefile_md5=$(md5sum < $SCRATCH_MNT/largefile) > > Hmm... is the tail '-' (printed by md5sum) as you wish? How about use the > _md5_checksum() in common/rc ? (Same as below small_md5 and large_md5 part) Ooh, nice suggestion. I"ll convert the test. > > + > > +# Try to force the creation of a single leaf block in each of three files. > > +# The first one gets a local attr, the second a remote attr, and the third > > +# is left for scrub and repair to find. > > +touch $SCRATCH_MNT/e0 > > +touch $SCRATCH_MNT/e1 > > +touch $SCRATCH_MNT/e2 > > + > > +$ATTR_PROG -s x $SCRATCH_MNT/e0 < $SCRATCH_MNT/smallfile >> $seqres.full > > +$ATTR_PROG -s x $SCRATCH_MNT/e1 < $SCRATCH_MNT/smallfile >> $seqres.full > > +$ATTR_PROG -s x $SCRATCH_MNT/e2 < $SCRATCH_MNT/smallfile >> $seqres.full > > + > > +e0_ino=$(stat -c '%i' $SCRATCH_MNT/e0) > > +e1_ino=$(stat -c '%i' $SCRATCH_MNT/e1) > > +e2_ino=$(stat -c '%i' $SCRATCH_MNT/e2) > > + > > +_scratch_unmount > > + > > +# We used to think that it wasn't possible for empty xattr leaf blocks to > > +# exist, but it turns out that setting a large xattr on a file that has no > > +# xattrs can race with a log flush and crash, which results in an empty > > +# leaf block being logged and recovered. This is rather hard to trip, so we > > +# use xfs_db to turn a regular leaf block into an empty one. > > +make_empty_leaf() { > > + local inum="$1" > > + > > + echo "editing inode $inum" >> $seqres.full > > + > > + magic=$(_scratch_xfs_get_metadata_field hdr.info.magic "inode $inum" "ablock 0") > > + if [ "$magic" = "0xfbee" ]; then > > + _notrun "V4 filesystems deprecated" > > Can _require_scratch_xfs_crc (at beginning) help that? Or is there a way to > get a v4 leaf block when crc isn't enabled? Nope, that was an oversight on my part. I'll add _require_scratch_xfs_crc to the start of the test. > > + return 1 > > I think _notrun will exit directly, this "return 1" never be run. Yep. > > + fi > > + > > + magic=$(_scratch_xfs_get_metadata_field hdr.info.hdr.magic "inode $inum" "ablock 0") > > + if [ "$magic" != "0x3bee" ]; then > > + echo "inode $inum ablock 0 is not a leaf block?" > > + _scratch_xfs_db -x -c "inode $inum" -c "ablock 0" -c print >> $seqres.full > > + return 1 > > + fi > > + > > + base=$(_scratch_xfs_get_metadata_field "hdr.freemap[0].base" "inode $inum" "ablock 0") > > + > > + _scratch_xfs_db -x -c "inode $inum" -c "ablock 0" \ > > + -c "write -d hdr.count 0" \ > > + -c "write -d hdr.usedbytes 0" \ > > + -c "write -d hdr.firstused $dbsize" \ > > + -c "write -d hdr.freemap[0].size $((dbsize - base))" \ > > Nice trick:) Do we expect there's not corruption (can be found by xfs_repair) > at here? Right. We're setting up the empty leaf block 0 to check that the kernel and fsck tools do /not/ flag this as corruption. > Or xfs_repair should blame the empty leaf block? ...though repair run in not-dryrun mode will free the empty leaf block 0 if it finds one. > > + -c print >> $seqres.full > > +} > > + > > +make_empty_leaf $e0_ino || exit > > How about call _fail() directly in make_empty_leaf, if [ "$magic" != "0x3bee" ] _require_scratch_xfs_crc should take care of that. > > +make_empty_leaf $e1_ino > > +make_empty_leaf $e2_ino > > + > > +_scratch_mount > > + > > +# Check that listxattr/getxattr/removexattr do nothing. > > +$ATTR_PROG -l $SCRATCH_MNT/e0 2>&1 | _filter_scratch > > +$ATTR_PROG -g x $SCRATCH_MNT/e0 2>&1 | _filter_scratch > > +$ATTR_PROG -r x $SCRATCH_MNT/e0 2>&1 | _filter_scratch > > + > > +# Add a small attr to e0 > > +$ATTR_PROG -s x $SCRATCH_MNT/e0 < $SCRATCH_MNT/smallfile > /dev/null > > +$ATTR_PROG -l $SCRATCH_MNT/e0 2>&1 | sed -e 's/\([0-9]*\) byte/XXX byte/g' | _filter_scratch > > +small_md5="$($GETFATTR_PROG -n user.x --absolute-names --only-values $SCRATCH_MNT/e0 | md5sum)" > > +test "$small_md5" = "$smallfile_md5" || \ > > + echo "smallfile $smallfile_md5 does not match small attr $small_md5" > > + > > +# Add a large attr to e1 > > +$ATTR_PROG -s x $SCRATCH_MNT/e1 < $SCRATCH_MNT/largefile > /dev/null > > +$ATTR_PROG -l $SCRATCH_MNT/e1 2>&1 | _filter_scratch > > +large_md5="$($GETFATTR_PROG -n user.x --absolute-names --only-values $SCRATCH_MNT/e1 | md5sum)" > > +test "$large_md5" = "$largefile_md5" || \ > > + echo "largefile $largefile_md5 does not match large attr $large_md5" > > + > > + > > +# Leave e2 to try to trip the repair tools, since xfs_repair used to flag > > +# empty leaf blocks incorrectly too. > > So we expect there's not corruption at here, and the empty leaf block can > be used properly? Correct. --D > Thanks, > Zorro > > > + > > +# success, all done > > +status=0 > > +exit > > >