Re: [PATCH 10/11] xfs: Check for extent overflow when swapping extents

Darrick J. Wong
2020-11-14T00:08:41Z

On Fri, Nov 13, 2020 at 04:57:02PM +0530, Chandan Babu R wrote:
> This test verifies that XFS does not cause inode fork's extent count to
> overflow when swapping forks across two files.
>
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> ---
> tests/xfs/530 | 115 ++++++++++++++++++++++++++++++++++++++++++++++
> tests/xfs/530.out | 13 ++++++
> tests/xfs/group | 1 +
> 3 files changed, 129 insertions(+)
> create mode 100755 tests/xfs/530
> create mode 100644 tests/xfs/530.out
>
> diff --git a/tests/xfs/530 b/tests/xfs/530
> new file mode 100755
> index 00000000..fccc6de7
> --- /dev/null
> +++ b/tests/xfs/530
> @@ -0,0 +1,115 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020 Chandan Babu R. All Rights Reserved.
> +#
> +# FS QA Test 530
> +#
> +# Verify that XFS does not cause inode fork's extent count to overflow when
> +# swapping forks between files
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1 # failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> + cd /
> + rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/inject
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +_supported_fs xfs
> +_require_scratch
> +_require_xfs_debug
> +_require_xfs_scratch_rmapbt
> +_require_xfs_io_command "fcollapse"
> +_require_xfs_io_command "swapext"

FWIW it's going to be a while before the swapext command goes upstream.
Right now it's a part of the atomic file range exchange patchset.

Do you want me to try to speed that up?

--D

> +_require_xfs_io_error_injection "reduce_max_iextents"
> +
> +echo "* Swap extent forks"
> +
> +echo "Format and mount fs"
> +_scratch_mkfs >> $seqres.full
> +_scratch_mount >> $seqres.full
> +
> +bsize=$(_get_block_size $SCRATCH_MNT)
> +
> +srcfile=${SCRATCH_MNT}/srcfile
> +donorfile=${SCRATCH_MNT}/donorfile
> +
> +echo "Create \$donorfile having an extent of length 17 blocks"
> +xfs_io -f -c "pwrite -b $((17 * bsize)) 0 $((17 * bsize))" -c fsync $donorfile \
> + >> $seqres.full
> +
> +# After the for loop the donor file will have the following extent layout
> +# | 0-4 | 5 | 6 | 7 | 8 | 9 | 10 |
> +echo "Fragment \$donorfile"
> +for i in $(seq 5 10); do
> + start_offset=$((i * bsize))
> + xfs_io -f -c "fcollapse $start_offset $bsize" $donorfile >> $seqres.full
> +done
> +donorino=$(stat -c "%i" $donorfile)
> +
> +echo "Create \$srcfile having an extent of length 18 blocks"
> +xfs_io -f -c "pwrite -b $((18 * bsize)) 0 $((18 * bsize))" -c fsync $srcfile \
> + >> $seqres.full
> +
> +echo "Fragment \$srcfile"
> +# After the for loop the src file will have the following extent layout
> +# | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7-10 |
> +for i in $(seq 1 7); do
> + start_offset=$((i * bsize))
> + xfs_io -f -c "fcollapse $start_offset $bsize" $srcfile >> $seqres.full
> +done
> +srcino=$(stat -c "%i" $srcfile)
> +
> +_scratch_unmount >> $seqres.full
> +
> +echo "Collect \$donorfile's extent count"
> +donor_nr_exts=$(_scratch_get_iext_count $donorino data || \
> + _fail "Unable to obtain inode fork's extent count")
> +
> +echo "Collect \$srcfile's extent count"
> +src_nr_exts=$(_scratch_get_iext_count $srcino data || \
> + _fail "Unable to obtain inode fork's extent count")
> +
> +_scratch_mount >> $seqres.full
> +
> +echo "Inject reduce_max_iextents error tag"
> +xfs_io -x -c 'inject reduce_max_iextents' $SCRATCH_MNT
> +
> +echo "Swap \$srcfile's and \$donorfile's extent forks"
> +xfs_io -f -c "swapext $donorfile" $srcfile >> $seqres.full 2>&1
> +
> +_scratch_unmount >> $seqres.full
> +
> +echo "Check for \$donorfile's extent count overflow"
> +nextents=$(_scratch_get_iext_count $donorino data || \
> + _fail "Unable to obtain inode fork's extent count")
> +if (( $nextents == $src_nr_exts )); then
> + echo "\$donorfile: Extent count overflow check failed"
> +fi
> +
> +echo "Check for \$srcfile's extent count overflow"
> +nextents=$(_scratch_get_iext_count $srcino data || \
> + _fail "Unable to obtain inode fork's extent count")
> +if (( $nextents == $donor_nr_exts )); then
> + echo "\$srcfile: Extent count overflow check failed"
> +fi
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/530.out b/tests/xfs/530.out
> new file mode 100644
> index 00000000..996af959
> --- /dev/null
> +++ b/tests/xfs/530.out
> @@ -0,0 +1,13 @@
> +QA output created by 530
> +* Swap extent forks
> +Format and mount fs
> +Create $donorfile having an extent of length 17 blocks
> +Fragment $donorfile
> +Create $srcfile having an extent of length 18 blocks
> +Fragment $srcfile
> +Collect $donorfile's extent count
> +Collect $srcfile's extent count
> +Inject reduce_max_iextents error tag
> +Swap $srcfile's and $donorfile's extent forks
> +Check for $donorfile's extent count overflow
> +Check for $srcfile's extent count overflow
> diff --git a/tests/xfs/group b/tests/xfs/group
> index bc3958b3..81a15582 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -527,3 +527,4 @@
> 527 auto quick
> 528 auto quick reflink
> 529 auto quick reflink
> +530 auto quick
> --
> 2.28.0
>