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 49001C433EF for ; Fri, 8 Jul 2022 15:08:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238270AbiGHPIP (ORCPT ); Fri, 8 Jul 2022 11:08:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237977AbiGHPIP (ORCPT ); Fri, 8 Jul 2022 11:08:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2038361D4E; Fri, 8 Jul 2022 08:08:14 -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 BA9D760B34; Fri, 8 Jul 2022 15:08:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D0DAC341C6; Fri, 8 Jul 2022 15:08:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657292893; bh=upStwKqoYbxAHZuaC5eK6/9bgoaMjoYWTR1yh4xO3XM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qUq45e5A6Wa4g6AKoNhfc2U4ImiIbLWerQEungxeQjCTzye6JKwFCFr9OZcENkSmW mK3pBJLqfX3+DrBZme7SA6DSYUP4v3UzJWm2yRGQKtTkWWHgBW/JPlvfNq/9GSiZUD khFoQvZPaLqw+7kLgInS43uZkOt1XZH13d5OVWEwJqx3Mq2Avq/VCLNwAfIgv0p5kI rrtxDUbbjFLKo/zpWo1MWMCNDS2gT4W94iNX2SsRWPAOCy3nLtjVhvgxxyJkMJ5bCp sjC1u6aaFQCZmqkPhTSh+W/rsC1rCNDF7pgewF5xons8T+xJCRjdRHOCKEeWmTYHoL eHtx3VQ0+QTfA== Date: Fri, 8 Jul 2022 08:08:12 -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> <20220708004916.tiidmzowad2wi3g4@zlang-mailbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220708004916.tiidmzowad2wi3g4@zlang-mailbox> Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Fri, Jul 08, 2022 at 08:49:16AM +0800, Zorro Lang wrote: > On Thu, Jul 07, 2022 at 11:22:14AM -0700, Darrick J. Wong wrote: > > 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. > > Hmm... I think _require_scratch_xfs_crc will help this: > > magic=$(_scratch_xfs_get_metadata_field hdr.info.magic "inode $inum" "ablock 0") > if [ "$magic" = "0xfbee" ]; then > > but can't help this part: > > magic=$(_scratch_xfs_get_metadata_field hdr.info.hdr.magic "inode $inum" "ablock 0") > if [ "$magic" != "0x3bee" ]; then > > due to ablock 0 might be 0x3ebe (XFS_DA3_NODE_MAGIC) besides 0x3bee, although > it looks nearly not impossible in this test, as you only create one attr equal > to inode size :) So if we make sure it never be a node block, it's fine to > remove this judgement, or you can keep it for sure. That's actually a good point, I should print out something if the magic number isn't 0x3bee, because that means a test precondition was not satisfied. (Granted, anything other than a leaf block and the _set commands will spray errors, but we could be explicit about not finding the leaf block we expected to see.) --D > Thanks, > Zorro > > > > > > > +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 > > > > > > > > > >