Re: [PATCH V6 10/13] xfs: Check for extent overflow when moving extent from cow to data fork

Allison Henderson
2021-03-10T22:42:31Z

On 3/8/21 10:01 PM, Chandan Babu R wrote:
> This test verifies that XFS does not cause inode fork's extent count to
> overflow when writing to/funshare-ing a shared extent.
>
> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
looks ok
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
> ---
> tests/xfs/534 | 104 ++++++++++++++++++++++++++++++++++++++++++++++
> tests/xfs/534.out | 12 ++++++
> tests/xfs/group | 1 +
> 3 files changed, 117 insertions(+)
> create mode 100755 tests/xfs/534
> create mode 100644 tests/xfs/534.out
>
> diff --git a/tests/xfs/534 b/tests/xfs/534
> new file mode 100755
> index 00000000..06b21f40
> --- /dev/null
> +++ b/tests/xfs/534
> @@ -0,0 +1,104 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2021 Chandan Babu R. All Rights Reserved.
> +#
> +# FS QA Test 534
> +#
> +# Verify that XFS does not cause inode fork's extent count to overflow when
> +# writing to a shared extent.
> +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/reflink
> +. ./common/inject
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +_supported_fs xfs
> +_require_scratch
> +_require_scratch_reflink
> +_require_xfs_debug
> +_require_xfs_io_command "reflink"
> +_require_xfs_io_command "funshare"
> +_require_xfs_io_error_injection "reduce_max_iextents"
> +
> +echo "Format and mount fs"
> +_scratch_mkfs_sized $((512 * 1024 * 1024)) >> $seqres.full
> +_scratch_mount >> $seqres.full
> +
> +bsize=$(_get_block_size $SCRATCH_MNT)
> +
> +nr_blks=15
> +
> +srcfile=${SCRATCH_MNT}/srcfile
> +dstfile=${SCRATCH_MNT}/dstfile
> +
> +echo "Inject reduce_max_iextents error tag"
> +_scratch_inject_error reduce_max_iextents 1
> +
> +echo "Create a \$srcfile having an extent of length $nr_blks blocks"
> +$XFS_IO_PROG -f -c "pwrite -b $((nr_blks * bsize)) 0 $((nr_blks * bsize))" \
> + -c fsync $srcfile >> $seqres.full
> +
> +echo "* Write to shared extent"
> +
> +echo "Share the extent with \$dstfile"
> +_reflink $srcfile $dstfile >> $seqres.full
> +
> +echo "Buffered write to every other block of \$dstfile's shared extent"
> +for i in $(seq 1 2 $((nr_blks - 1))); do
> + $XFS_IO_PROG -f -s -c "pwrite $((i * bsize)) $bsize" $dstfile \
> + >> $seqres.full 2>&1
> + [[ $? != 0 ]] && break
> +done
> +
> +echo "Verify \$dstfile's extent count"
> +nextents=$(_xfs_get_fsxattr nextents $dstfile)
> +if (( $nextents > 10 )); then
> + echo "Extent count overflow check failed: nextents = $nextents"
> + exit 1
> +fi
> +
> +rm $dstfile
> +
> +echo "* Funshare shared extent"
> +
> +echo "Share the extent with \$dstfile"
> +_reflink $srcfile $dstfile >> $seqres.full
> +
> +echo "Funshare every other block of \$dstfile's shared extent"
> +for i in $(seq 1 2 $((nr_blks - 1))); do
> + $XFS_IO_PROG -f -s -c "funshare $((i * bsize)) $bsize" $dstfile \
> + >> $seqres.full 2>&1
> + [[ $? != 0 ]] && break
> +done
> +
> +echo "Verify \$dstfile's extent count"
> +nextents=$(_xfs_get_fsxattr nextents $dstfile)
> +if (( $nextents > 10 )); then
> + echo "Extent count overflow check failed: nextents = $nextents"
> + exit 1
> +fi
> +
> +# success, all done
> +status=0
> +exit
> +
> diff --git a/tests/xfs/534.out b/tests/xfs/534.out
> new file mode 100644
> index 00000000..53288d12
> --- /dev/null
> +++ b/tests/xfs/534.out
> @@ -0,0 +1,12 @@
> +QA output created by 534
> +Format and mount fs
> +Inject reduce_max_iextents error tag
> +Create a $srcfile having an extent of length 15 blocks
> +* Write to shared extent
> +Share the extent with $dstfile
> +Buffered write to every other block of $dstfile's shared extent
> +Verify $dstfile's extent count
> +* Funshare shared extent
> +Share the extent with $dstfile
> +Funshare every other block of $dstfile's shared extent
> +Verify $dstfile's extent count
> diff --git a/tests/xfs/group b/tests/xfs/group
> index 3ad47d07..b4f0c777 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -531,3 +531,4 @@
> 531 auto quick attr
> 532 auto quick dir hardlink symlink
> 533 auto quick
> +534 auto quick reflink
>