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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=unavailable 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 0409FC433EF for ; Sun, 5 Sep 2021 14:28:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5CAB60F21 for ; Sun, 5 Sep 2021 14:28:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233758AbhIEO3W (ORCPT ); Sun, 5 Sep 2021 10:29:22 -0400 Received: from out20-87.mail.aliyun.com ([115.124.20.87]:49716 "EHLO out20-87.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229566AbhIEO3V (ORCPT ); Sun, 5 Sep 2021 10:29:21 -0400 X-Alimail-AntiSpam: AC=CONTINUE;BC=0.07436299|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_alarm|0.337392-0.0244149-0.638193;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047207;MF=guan@eryu.me;NM=1;PH=DS;RN=4;RT=4;SR=0;TI=SMTPD_---.LFticQR_1630852096; Received: from localhost(mailfrom:guan@eryu.me fp:SMTPD_---.LFticQR_1630852096) by smtp.aliyun-inc.com(10.147.40.233); Sun, 05 Sep 2021 22:28:16 +0800 Date: Sun, 5 Sep 2021 22:28:16 +0800 From: Eryu Guan To: "Darrick J. Wong" Cc: guaneryu@gmail.com, linux-xfs@vger.kernel.org, fstests@vger.kernel.org Subject: Re: [PATCH 1/3] xfs: test fsx with extent size hints set on a realtime file Message-ID: References: <163045508495.769915.4859353445119566326.stgit@magnolia> <163045509043.769915.12768254084054792591.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <163045509043.769915.12768254084054792591.stgit@magnolia> Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Tue, Aug 31, 2021 at 05:11:30PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > This is a regression test for the two realtime allocator bug fixes: > > xfs: adjust rt allocation minlen when extszhint > rtextsize > xfs: retry allocations when locality-based search fails > > Signed-off-by: Darrick J. Wong Looks fine to me, just a few minor nits inline. > --- > tests/xfs/775 | 165 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > tests/xfs/775.out | 3 + > 2 files changed, 168 insertions(+) > create mode 100755 tests/xfs/775 > create mode 100644 tests/xfs/775.out > > > diff --git a/tests/xfs/775 b/tests/xfs/775 > new file mode 100755 > index 00000000..e8e6b728 > --- /dev/null > +++ b/tests/xfs/775 > @@ -0,0 +1,165 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (c) 2021, Oracle. All Rights Reserved. > +# > +# FS QA Test No. 775 > +# > +# Regression test for commits: > +# > +# 9d5e8492eee0 ("xfs: adjust rt allocation minlen when extszhint > rtextsize") > +# 676a659b60af ("xfs: retry allocations when locality-based search fails") > +# > +# The first bug occurs when an extent size hint is set on a realtime file. > +# xfs_bmapi_rtalloc adjusts the offset and length of the allocation request to > +# try to satisfy the hint, but doesn't adjust minlen to match. If the > +# allocator finds free space that isn't large enough to map even a single block > +# of the original request, bmapi_write will return ENOSPC and the write fails > +# even though there's plenty of space. > +# > +# The second bug occurs when an extent size hint is set on a file, we ask to > +# allocate blocks in an empty region immediately adjacent to a previous > +# allocation, and the nearest available free space isn't anywhere near the > +# previous allocation, the near allocator will give up and return ENOSPC, even > +# if there's sufficient free realtime extents to satisfy the allocation > +# request. > +# > +# Both bugs can be exploited by the same user call sequence, so here's a > +# targeted test that runs in less time than the reproducers that are listed in > +# the fix patches themselves. > +# > +. ./common/preamble > +_begin_fstest auto quick rw realtime > + > +# Override the default cleanup function. > +_cleanup() > +{ > + cd / > +} Seems there's no need to override the default cleanup function? > + > +# Import common functions. > +. ./common/filter > + > +# real QA test starts here _supported_fs xfs > +_require_scratch > +_require_realtime > +_require_xfs_io_command "falloc" > +_require_xfs_io_command "fpunch" > +_require_test_program "punch-alternating" > + > +fill_rtdev() > +{ > + file=$1 > + > + filesize=`_get_available_space $SCRATCH_MNT` > + $XFS_IO_PROG -f -c "truncate $filesize" -c "falloc 0 $filesize" $file > + > + chunks=20 > + chunksizemb=$((filesize / chunks / 1048576)) > + seq 1 $chunks | while read f; do > + echo "$((f * chunksizemb)) file size $f / 20" > + $XFS_IO_PROG -fc "falloc -k $(( (f - 1) * chunksizemb))m ${chunksizemb}m" $file > + done > + > + chunks=100 > + chunksizemb=$((filesize / chunks / 1048576)) > + seq 80 $chunks | while read f; do > + echo "$((f * chunksizemb)) file size $f / $chunks" > + $XFS_IO_PROG -fc "falloc -k $(( (f - 1) * chunksizemb))m ${chunksizemb}m" $file > + done > + > + filesizemb=$((filesize / 1048576)) > + $XFS_IO_PROG -fc "falloc -k 0 ${filesizemb}m" $file > + > + # Try again anyway > + avail=`_get_available_space $SCRATCH_MNT` > + $XFS_IO_PROG -fc "pwrite -S 0x65 0 $avail" ${file} > +} > + > +echo "Format and mount" > +_scratch_mkfs > $seqres.full 2>&1 > +_scratch_mount >> $seqres.full 2>&1 > + > +# This is a test of the rt allocator; force all files to be created realtime > +_xfs_force_bdev realtime $SCRATCH_MNT > + > +# Set the extent size hint larger than the realtime extent size. This is > +# necessary to exercise the minlen constraints on the realtime allocator. > +fsbsize=$($XFS_IO_PROG -c 'statfs' $SCRATCH_MNT | grep geom.bsize | awk '{print $3}') > +rtextsize_blks=$($XFS_IO_PROG -c 'statfs' $SCRATCH_MNT | grep geom.rtextsize | awk '{print $3}') > +extsize=$((2 * rtextsize_blks * fsbsize)) > + > +echo "rtextsize_blks=$rtextsize_blks extsize=$extsize" >> $seqres.full > +_xfs_force_bdev realtime $SCRATCH_MNT Already done above, could be removed? Thanks, Eryu > +$XFS_IO_PROG -c "extsize $extsize" $SCRATCH_MNT > + > +# Compute the geometry of the test files we're going to create. Realtime > +# volumes are simple, which means that we can control the space allocations > +# exactly to exploit bugs! > +# > +# Since this is a test of the near rt allocator, we need to set up the test to > +# have a victim file with at least one rt extent allocated to it and enough > +# free space to allocate at least one more rt extent at an adjacent file > +# offset. The free space must not be immediately adjacent to the the first > +# extent that we allocate to the victim file, and it must not be large enough > +# to satisfy the entire allocation request all at once. > +# > +# Our free space fragmentation strategy is the usual fallocate-and-punch swiss > +# cheese file, which means the free space is split into five sections: > +# > +# The first will be remapped into the victim file. > +# > +# The second section exists to prevent the free extents from being adjacent to > +# the first section. It will be very large, since we allocate all the rt > +# space. > +# > +# The last three sections will have every other rt extent punched out to create > +# some free space. > +remap_sz=$((extsize * 2)) > +required_sz=$((5 * remap_sz)) > +free_rtspace=$(_get_available_space $SCRATCH_MNT) > +if [ $free_rtspace -lt $required_sz ]; then > + _notrun "Insufficient free space on rt volume. Needed $required_sz, saw $free_rtspace." > +fi > + > +# Allocate all the space on the rt volume so that we can control space > +# allocations exactly. > +fill_rtdev $SCRATCH_MNT/bigfile &>> $seqres.full > + > +# We need at least 4 remap sections to proceed > +bigfile_sz=$(stat -c '%s' $SCRATCH_MNT/bigfile) > +if [ $bigfile_sz -lt $required_sz ]; then > + _notrun "Free space control file needed $required_sz bytes, got $bigfile_sz." > +fi > + > +# Remap the first remap section to a victim file. > +$XFS_IO_PROG -c "fpunch 0 $remap_sz" $SCRATCH_MNT/bigfile > +$XFS_IO_PROG -f -c "truncate $required_sz" -c "falloc 0 $remap_sz" $SCRATCH_MNT/victim > + > +# Punch out every other extent of the last two sections, to fragment free space. > +frag_sz=$((remap_sz * 3)) > +punch_off=$((bigfile_sz - frag_sz)) > +$here/src/punch-alternating $SCRATCH_MNT/bigfile -o $((punch_off / fsbsize)) -i $((rtextsize_blks * 2)) -s $rtextsize_blks > + > +# Make sure we have some free rtextents. > +free_rtx=$($XFS_IO_PROG -c 'statfs' $SCRATCH_MNT | grep counts.freertx | awk '{print $3}') > +if [ $free_rtx -eq 0 ]; then > + echo "Expected fragmented free rt space, found none." > +fi > + > +# Try to double the amount of blocks in the victim file. On a buggy kernel, > +# the rt allocator will fail immediately with ENOSPC even though we left enough > +# free space for the write will complete fully. > +echo "Try to write a bunch of stuff to the fragmented rt space" > +$XFS_IO_PROG -c "pwrite -S 0x63 -b $remap_sz $remap_sz $remap_sz" -c stat $SCRATCH_MNT/victim >> $seqres.full > + > +# The victim file should own at least two sections' worth of blocks. > +victim_sectors=$(stat -c '%b' $SCRATCH_MNT/victim) > +victim_space_usage=$((victim_sectors * 512)) > +expected_usage=$((remap_sz * 2)) > + > +if [ $victim_space_usage -lt $expected_usage ]; then > + echo "Victim file should be using at least $expected_usage bytes, saw $victim_space_usage." > +fi > + > +status=0 > +exit > diff --git a/tests/xfs/775.out b/tests/xfs/775.out > new file mode 100644 > index 00000000..f5a72156 > --- /dev/null > +++ b/tests/xfs/775.out > @@ -0,0 +1,3 @@ > +QA output created by 775 > +Format and mount > +Try to write a bunch of stuff to the fragmented rt space