Re: [PATCH 07/11] xfs: Check for extent overflow when writing to unwritten extent

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Fri, Nov 13, 2020 at 04:56:59PM +0530, Chandan Babu R wrote:
> This test verifies that XFS does not cause inode fork's extent count to
> overflow when writing to an unwritten extent.
> 
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> ---
>  tests/xfs/527     | 125 ++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/527.out |  13 +++++
>  tests/xfs/group   |   1 +
>  3 files changed, 139 insertions(+)
>  create mode 100755 tests/xfs/527
>  create mode 100644 tests/xfs/527.out
> 
> diff --git a/tests/xfs/527 b/tests/xfs/527
> new file mode 100755
> index 00000000..f040aee4
> --- /dev/null
> +++ b/tests/xfs/527
> @@ -0,0 +1,125 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020 Chandan Babu R.  All Rights Reserved.
> +#
> +# FS QA Test 527
> +#
> +# Verify that XFS does not cause inode fork's extent count to overflow when
> +# writing to an unwritten 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/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_io_command "falloc"
> +_require_xfs_io_error_injection "reduce_max_iextents"
> +
> +buffered_write_to_unwritten_extent()

This is nearly the same as the directio write test; could you combine
them into a single function so we have fewer functions to maintain?

--D

> +{
> +	echo "* Buffered write to unwritten extent"
> +
> +	echo "Format and mount fs"
> +	_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full
> +	_scratch_mount >> $seqres.full
> +
> +	bsize=$(_get_block_size $SCRATCH_MNT)
> +
> +	testfile=${SCRATCH_MNT}/testfile
> +
> +	nr_blks=15
> +
> +	echo "Fallocate $nr_blks blocks"
> +	xfs_io -f -c "falloc 0 $((nr_blks * bsize))" $testfile >> $seqres.full
> +
> +	echo "Inject reduce_max_iextents error tag"
> +	xfs_io -x -c "inject reduce_max_iextents" $SCRATCH_MNT
> +
> +	echo "Buffered write to every other block of fallocated space"
> +	for i in $(seq 1 2 $((nr_blks - 1))); do
> +		xfs_io -f -c "pwrite $((i * bsize)) $bsize" -c fsync $testfile \
> +		       >> $seqres.full 2>&1
> +		[[ $? != 0 ]] && break
> +	done
> +
> +	testino=$(stat -c "%i" $testfile)
> +
> +	_scratch_unmount >> $seqres.full
> +
> +	echo "Verify \$testfile's extent count"
> +
> +	nextents=$(_scratch_get_iext_count $testino data || \
> +			_fail "Unable to obtain inode fork's extent count")
> +	if (( $nextents > 10 )); then
> +		echo "Extent count overflow check failed: nextents = $nextents"
> +	fi
> +}
> +
> +direct_write_to_unwritten_extent()
> +{
> +	echo "* Direct I/O write to unwritten extent"
> +
> +	echo "Format and mount fs"
> +	_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full
> +	_scratch_mount >> $seqres.full
> +
> +	bsize=$(_get_block_size $SCRATCH_MNT)
> +
> +	testfile=${SCRATCH_MNT}/testfile
> +
> +	nr_blks=15
> +
> +	echo "Fallocate $nr_blks blocks"
> +	xfs_io -f -c "falloc 0 $((nr_blks * bsize))" $testfile >> $seqres.full
> +
> +	echo "Inject reduce_max_iextents error tag"
> +	xfs_io -x -c "inject reduce_max_iextents" $SCRATCH_MNT
> +
> +	echo "Direct I/O write to every other block of fallocated space"
> +	for i in $(seq 1 2 $((nr_blks - 1))); do
> +		xfs_io -f -d -c "pwrite $((i * bsize)) $bsize" $testfile \
> +		       >> $seqres.full 2>&1
> +		[[ $? != 0 ]] && break
> +	done
> +
> +	testino=$(stat -c "%i" $testfile)
> +
> +	_scratch_unmount >> $seqres.full
> +
> +	echo "Verify \$testfile's extent count"
> +
> +	nextents=$(_scratch_get_iext_count $testino data || \
> +			_fail "Unable to obtain inode fork's extent count")
> +	if (( $nextents > 10 )); then
> +		echo "Extent count overflow check failed: nextents = $nextents"
> +	fi
> +}
> +
> +buffered_write_to_unwritten_extent
> +direct_write_to_unwritten_extent
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/527.out b/tests/xfs/527.out
> new file mode 100644
> index 00000000..6aa5e9ed
> --- /dev/null
> +++ b/tests/xfs/527.out
> @@ -0,0 +1,13 @@
> +QA output created by 527
> +* Buffered write to unwritten extent
> +Format and mount fs
> +Fallocate 15 blocks
> +Inject reduce_max_iextents error tag
> +Buffered write to every other block of fallocated space
> +Verify $testfile's extent count
> +* Direct I/O write to unwritten extent
> +Format and mount fs
> +Fallocate 15 blocks
> +Inject reduce_max_iextents error tag
> +Direct I/O write to every other block of fallocated space
> +Verify $testfile's extent count
> diff --git a/tests/xfs/group b/tests/xfs/group
> index d089797b..627813fe 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -524,3 +524,4 @@
>  524 auto quick punch zero insert collapse
>  525 auto quick attr
>  526 auto quick dir hardlink symlink
> +527 auto quick
> -- 
> 2.28.0
>