From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1679F1FDD; Tue, 24 Sep 2024 15:03:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727190197; cv=none; b=oRQxhJLzWzT8C3D+BAktIfO4csNe7hCy2G1MrpNfJwNL0lPOLD6kVSixTzhHjBoJnVVHPNLgRw4S0aPrQFzPWKyul1wJ3G1gcnJ+Qgvdb9x6BopQ4kmtbk+N9yAh57XfTPnkAYDt76lr32tD5Y6Hem8MBm3FN/V0EHoUwJrsxOs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727190197; c=relaxed/simple; bh=fbHJ9ybr+udNypmoDs5mZsOKlu2XH/zjqlEsEqG6/Fo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ezH8gBKtb2M5jZ7O2CB0hvj+K8csP2vHyq9Umk05XSwDWuwahBEl8cosVIvK0HTMhI2Y4DEFP7KJCYxSSEDD3jerKrgojsxvA9vUrl1dVCzrloABNNPhDq4rKqBNKp3QNkl5yfuEtvmBm6l51lJ7QaE5rWfmeB1iONpO3lGrCYk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=StFb9FoB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="StFb9FoB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EB5EC4CEC4; Tue, 24 Sep 2024 15:03:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727190196; bh=fbHJ9ybr+udNypmoDs5mZsOKlu2XH/zjqlEsEqG6/Fo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=StFb9FoBmptK+1KcJ2SC2F1Vgk7VajFIGlL5Dvgs/GGfqWdPnyekOL+4hBb1D+3jW ZxlztP/4U/QnkljVsWelCRGy5mczDFdd7M2lAXKWGtLCCsmxTVKtPb9gU8xJywBYIV UYmmCSwMW3RykIRWqG3YldIiB/rNOZnhGwV0hE87VKyvb7ONf6XC7ZQnIgL+A5UV1/ ZPvFu3U1/QHi/6LsE9XlJh1YR34QvQODTn4VDJjFN74lasZnRNAygU+fa52fGj4CLL LdIM4lKw5ngXSbXtAYZtYOB+yRqNRYDKQOXyw9fVWHayGBHYmGRUI1v/lQ4od+em1L +Z06WJjfS2KRw== Date: Tue, 24 Sep 2024 08:03:15 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Zorro Lang , Dave Chinner , linux-xfs@vger.kernel.org, fstests@vger.kernel.org Subject: Re: [PATCH] xfs: new EOF fragmentation tests Message-ID: <20240924150315.GH21853@frogsfrogsfrogs> References: <20240924084551.1802795-1-hch@lst.de> <20240924084551.1802795-2-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240924084551.1802795-2-hch@lst.de> On Tue, Sep 24, 2024 at 10:45:48AM +0200, Christoph Hellwig wrote: > From: Dave Chinner > > These tests create substantial file fragmentation as a result of > application actions that defeat post-EOF preallocation > optimisations. They are intended to replicate known vectors for > these problems, and provide a check that the fragmentation levels > have been controlled. The mitigations we make may not completely > remove fragmentation (e.g. they may demonstrate speculative delalloc > related extent size growth) so the checks don't assume we'll end up > with perfect layouts and hence check for an exceptable level of > fragmentation rather than none. > > Signed-off-by: Dave Chinner > [move to different test number, update to current xfstest APIs] > Signed-off-by: Christoph Hellwig > --- > tests/xfs/1500 | 66 +++++++++++++++++++++++++++++++++++++++ > tests/xfs/1500.out | 9 ++++++ > tests/xfs/1501 | 68 ++++++++++++++++++++++++++++++++++++++++ > tests/xfs/1501.out | 9 ++++++ > tests/xfs/1502 | 68 ++++++++++++++++++++++++++++++++++++++++ > tests/xfs/1502.out | 9 ++++++ > tests/xfs/1503 | 77 ++++++++++++++++++++++++++++++++++++++++++++++ > tests/xfs/1503.out | 33 ++++++++++++++++++++ > 8 files changed, 339 insertions(+) > create mode 100755 tests/xfs/1500 > create mode 100644 tests/xfs/1500.out > create mode 100755 tests/xfs/1501 > create mode 100644 tests/xfs/1501.out > create mode 100755 tests/xfs/1502 > create mode 100644 tests/xfs/1502.out > create mode 100755 tests/xfs/1503 > create mode 100644 tests/xfs/1503.out > > diff --git a/tests/xfs/1500 b/tests/xfs/1500 > new file mode 100755 > index 000000000..de0e1df62 > --- /dev/null > +++ b/tests/xfs/1500 > @@ -0,0 +1,66 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (c) 2019 Red Hat, Inc. All Rights Reserved. > +# > +# FS QA Test xfs/500 Should be "FS QA Test 1500" or at least not say "xfs/500" given the filename. Same for the other tests. > +# > +# Post-EOF preallocation defeat test for O_SYNC buffered I/O. > +# > + > +. ./common/preamble > +_begin_fstest auto quick prealloc rw > + > +. ./common/rc > +. ./common/filter > + > +_require_scratch > + > +_cleanup() > +{ > + # try to kill all background processes > + wait > + cd / > + rm -r -f $tmp.* > +} > + > +_scratch_mkfs > "$seqres.full" 2>&1 > +_scratch_mount > + > +# Write multiple files in parallel using synchronous buffered writes. Aim is to > +# interleave allocations to fragment the files. Synchronous writes defeat the > +# open/write/close heuristics in xfs_file_release() that prevent EOF block > +# removal, so this should fragment badly. Typical problematic behaviour shows > +# per-file extent counts of >900 (almost worse case) whilst fixed behaviour > +# typically shows extent counts in the low 20s. > +# > +# Failure is determined by golden output mismatch from _within_tolerance(). > + > +workfile=$SCRATCH_MNT/file > +nfiles=8 > +wsize=4096 Shouldn't this be _get_file_block_size instead of hardcoded 4k? Same for all the other tests. > +wcnt=1000 > + > +write_sync_file() > +{ > + idx=$1 > + > + for ((cnt=0; cnt<$wcnt; cnt++)); do > + $XFS_IO_PROG -f -s -c "pwrite $((cnt * wsize)) $wsize" $workfile.$idx > + done > +} > + > +rm -f $workfile* > +for ((n=0; n<$nfiles; n++)); do > + write_sync_file $n > /dev/null 2>&1 & > +done > +wait > +sync > + > +for ((n=0; n<$nfiles; n++)); do > + count=$(_count_extents $workfile.$n) > + # Acceptible extent count range is 1-40 > + _within_tolerance "file.$n extent count" $count 21 19 -v > +done > + > +status=0 > +exit > diff --git a/tests/xfs/1500.out b/tests/xfs/1500.out > new file mode 100644 > index 000000000..414df87ed > --- /dev/null > +++ b/tests/xfs/1500.out > @@ -0,0 +1,9 @@ > +QA output created by 1500 > +file.0 extent count is in range > +file.1 extent count is in range > +file.2 extent count is in range > +file.3 extent count is in range > +file.4 extent count is in range > +file.5 extent count is in range > +file.6 extent count is in range > +file.7 extent count is in range > diff --git a/tests/xfs/1501 b/tests/xfs/1501 > new file mode 100755 > index 000000000..cf3cbf8b5 > --- /dev/null > +++ b/tests/xfs/1501 > @@ -0,0 +1,68 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (c) 2019 Red Hat, Inc. All Rights Reserved. > +# > +# FS QA Test xfs/501 > +# > +# Post-EOF preallocation defeat test for buffered I/O with extent size hints. > +# > + > +. ./common/preamble > +_begin_fstest auto quick prealloc rw > + > +. ./common/rc > +. ./common/filter > + > +_require_scratch > + > +_cleanup() > +{ > + # try to kill all background processes > + wait > + cd / > + rm -r -f $tmp.* > +} > + > +_scratch_mkfs > "$seqres.full" 2>&1 > +_scratch_mount > + > +# Write multiple files in parallel using buffered writes with extent size hints. > +# Aim is to interleave allocations to fragment the files. Writes w/ extent size > +# hints set defeat the open/write/close heuristics in xfs_file_release() that > +# prevent EOF block removal, so this should fragment badly. Typical problematic > +# behaviour shows per-file extent counts of 1000 (worst case!) whilst > +# fixed behaviour should show very few extents (almost best case). > +# > +# Failure is determined by golden output mismatch from _within_tolerance(). > + > +workfile=$SCRATCH_MNT/file > +nfiles=8 > +wsize=4096 > +wcnt=1000 > +extent_size=16m > + > +write_extsz_file() > +{ > + idx=$1 > + > + $XFS_IO_PROG -f -c "extsize $extent_size" $workfile.$idx > + for ((cnt=0; cnt<$wcnt; cnt++)); do > + $XFS_IO_PROG -f -c "pwrite $((cnt * wsize)) $wsize" $workfile.$idx > + done > +} > + > +rm -f $workfile* > +for ((n=0; n<$nfiles; n++)); do > + write_extsz_file $n > /dev/null 2>&1 & > +done > +wait > +sync > + > +for ((n=0; n<$nfiles; n++)); do > + count=$(_count_extents $workfile.$n) > + # Acceptible extent count range is 1-10 > + _within_tolerance "file.$n extent count" $count 2 1 8 -v > +done > + > +status=0 > +exit > diff --git a/tests/xfs/1501.out b/tests/xfs/1501.out > new file mode 100644 > index 000000000..a266ef74b > --- /dev/null > +++ b/tests/xfs/1501.out > @@ -0,0 +1,9 @@ > +QA output created by 1501 > +file.0 extent count is in range > +file.1 extent count is in range > +file.2 extent count is in range > +file.3 extent count is in range > +file.4 extent count is in range > +file.5 extent count is in range > +file.6 extent count is in range > +file.7 extent count is in range > diff --git a/tests/xfs/1502 b/tests/xfs/1502 > new file mode 100755 > index 000000000..f4228667a > --- /dev/null > +++ b/tests/xfs/1502 > @@ -0,0 +1,68 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (c) 2019 Red Hat, Inc. All Rights Reserved. > +# > +# FS QA Test xfs/502 > +# > +# Post-EOF preallocation defeat test for direct I/O with extent size hints. > +# > + > +. ./common/preamble > +_begin_fstest auto quick prealloc rw > + > +. ./common/rc > +. ./common/filter > + > +_require_scratch This one wants _require_odirect in case we ever disable directio for some weird xfs config. > + > +_cleanup() > +{ > + # try to kill all background processes > + wait > + cd / > + rm -r -f $tmp.* > +} > + > +_scratch_mkfs > "$seqres.full" 2>&1 > +_scratch_mount > + > +# Write multiple files in parallel using O_DIRECT writes w/ extent size hints. > +# Aim is to interleave allocations to fragment the files. O_DIRECT writes defeat > +# the open/write/close heuristics in xfs_file_release() that prevent EOF block > +# removal, so this should fragment badly. Typical problematic behaviour shows > +# per-file extent counts of ~1000 (worst case) whilst fixed behaviour typically > +# shows extent counts in the low single digits (almost best case) > +# > +# Failure is determined by golden output mismatch from _within_tolerance(). > + > +workfile=$SCRATCH_MNT/file > +nfiles=8 > +wsize=4096 > +wcnt=1000 > +extent_size=16m > + > +write_direct_file() > +{ > + idx=$1 > + > + $XFS_IO_PROG -f -c "extsize $extent_size" $workfile.$idx > + for ((cnt=0; cnt<$wcnt; cnt++)); do > + $XFS_IO_PROG -f -d -c "pwrite $((cnt * wsize)) $wsize" $workfile.$idx > + done > +} > + > +rm -f $workfile* > +for ((n=0; n<$nfiles; n++)); do > + write_direct_file $n > /dev/null 2>&1 & > +done > +wait > +sync > + > +for ((n=0; n<$nfiles; n++)); do > + count=$(_count_extents $workfile.$n) > + # Acceptible extent count range is 1-10 > + _within_tolerance "file.$n extent count" $count 2 1 8 -v > +done > + > +status=0 > +exit > diff --git a/tests/xfs/1502.out b/tests/xfs/1502.out > new file mode 100644 > index 000000000..82c8760a3 > --- /dev/null > +++ b/tests/xfs/1502.out > @@ -0,0 +1,9 @@ > +QA output created by 1502 > +file.0 extent count is in range > +file.1 extent count is in range > +file.2 extent count is in range > +file.3 extent count is in range > +file.4 extent count is in range > +file.5 extent count is in range > +file.6 extent count is in range > +file.7 extent count is in range > diff --git a/tests/xfs/1503 b/tests/xfs/1503 > new file mode 100755 > index 000000000..9002f87e6 > --- /dev/null > +++ b/tests/xfs/1503 > @@ -0,0 +1,77 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (c) 2019 Red Hat, Inc. All Rights Reserved. > +# > +# FS QA Test xfs/503 > +# > +# Post-EOF preallocation defeat test with O_SYNC buffered I/O that repeatedly > +# closes and reopens the files. > +# > + > +. ./common/preamble > +_begin_fstest auto prealloc rw > + > +. ./common/rc > +. ./common/filter > + > +_require_scratch > + > +_cleanup() > +{ > + # try to kill all background processes > + wait > + cd / > + rm -r -f $tmp.* > +} > + > +_scratch_mkfs > "$seqres.full" 2>&1 > +_scratch_mount > + > +# Write multiple files in parallel using synchronous buffered writes that > +# repeatedly close and reopen the fails. Aim is to interleave allocations to > +# fragment the files. Assuming we've fixed the synchronous write defeat, we can > +# still trigger the same issue with a open/read/close on O_RDONLY files. We > +# should not be triggering EOF preallocation removal on files we don't have > +# permission to write, so until this is fixed it should fragment badly. Typical > +# problematic behaviour shows per-file extent counts of 50-350 whilst fixed > +# behaviour typically demonstrates post-eof speculative delalloc growth in > +# extent size (~6 extents for 50MB file). > +# > +# Failure is determined by golden output mismatch from _within_tolerance(). > + > +workfile=$SCRATCH_MNT/file > +nfiles=32 > +wsize=4096 > +wcnt=1000 > + > +write_file() > +{ > + idx=$1 > + > + $XFS_IO_PROG -f -s -c "pwrite -b 64k 0 50m" $workfile.$idx > +} > + > +read_file() > +{ > + idx=$1 > + > + for ((cnt=0; cnt<$wcnt; cnt++)); do > + $XFS_IO_PROG -f -r -c "pread 0 28" $workfile.$idx > + done > +} > + > +rm -f $workdir/file* > +for ((n=0; n<$((nfiles)); n++)); do > + write_file $n > /dev/null 2>&1 & > + read_file $n > /dev/null 2>&1 & > +done > +wait > + > +for ((n=0; n<$nfiles; n++)); do > + count=$(_count_extents $workfile.$n) > + # Acceptible extent count range is 1-40 > + _within_tolerance "file.$n extent count" $count 6 5 10 -v > +done > + > +status=0 > +exit > diff --git a/tests/xfs/1503.out b/tests/xfs/1503.out > new file mode 100644 > index 000000000..1780b16df > --- /dev/null > +++ b/tests/xfs/1503.out > @@ -0,0 +1,33 @@ > +QA output created by 1503 > +file.0 extent count is in range > +file.1 extent count is in range > +file.2 extent count is in range > +file.3 extent count is in range > +file.4 extent count is in range > +file.5 extent count is in range > +file.6 extent count is in range > +file.7 extent count is in range > +file.8 extent count is in range > +file.9 extent count is in range > +file.10 extent count is in range > +file.11 extent count is in range > +file.12 extent count is in range > +file.13 extent count is in range > +file.14 extent count is in range > +file.15 extent count is in range > +file.16 extent count is in range > +file.17 extent count is in range > +file.18 extent count is in range > +file.19 extent count is in range > +file.20 extent count is in range > +file.21 extent count is in range > +file.22 extent count is in range > +file.23 extent count is in range > +file.24 extent count is in range > +file.25 extent count is in range > +file.26 extent count is in range > +file.27 extent count is in range > +file.28 extent count is in range > +file.29 extent count is in range > +file.30 extent count is in range > +file.31 extent count is in range > -- > 2.45.2 > >