Re: [PATCH V5 04/13] xfs: Check for extent overflow when trivally adding a new extent

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Mar 08, 2021 at 09:21:02PM +0530, Chandan Babu R wrote:
> This test verifies that XFS does not cause inode fork's extent count to
> overflow when adding a single extent while there's no possibility of splitting
> an existing mapping.
> 
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>

Looks ok,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  tests/xfs/528     | 171 ++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/528.out |  20 ++++++
>  tests/xfs/group   |   1 +
>  3 files changed, 192 insertions(+)
>  create mode 100755 tests/xfs/528
>  create mode 100644 tests/xfs/528.out
> 
> diff --git a/tests/xfs/528 b/tests/xfs/528
> new file mode 100755
> index 00000000..5eb1021a
> --- /dev/null
> +++ b/tests/xfs/528
> @@ -0,0 +1,171 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2021 Chandan Babu R.  All Rights Reserved.
> +#
> +# FS QA Test 528
> +#
> +# Verify that XFS does not cause inode fork's extent count to overflow when
> +# adding a single extent while there's no possibility of splitting an existing
> +# mapping.
> +
> +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/quota
> +. ./common/inject
> +. ./common/populate
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +_supported_fs xfs
> +_require_scratch
> +_require_xfs_quota
> +_require_xfs_debug
> +_require_test_program "punch-alternating"
> +_require_xfs_io_command "falloc"
> +_require_xfs_io_error_injection "reduce_max_iextents"
> +_require_xfs_io_error_injection "bmap_alloc_minlen_extent"
> +
> +echo "Format and mount fs"
> +_scratch_mkfs_sized $((512 * 1024 * 1024)) >> $seqres.full
> +_scratch_mount -o uquota >> $seqres.full
> +
> +bsize=$(_get_file_block_size $SCRATCH_MNT)
> +
> +echo "* Delalloc to written extent conversion"
> +
> +testfile=$SCRATCH_MNT/testfile
> +
> +echo "Inject reduce_max_iextents error tag"
> +_scratch_inject_error reduce_max_iextents 1
> +
> +nr_blks=$((15 * 2))
> +
> +echo "Create fragmented file"
> +for i in $(seq 0 2 $((nr_blks - 1))); do
> +	$XFS_IO_PROG -f -s -c "pwrite $((i * bsize)) $bsize" $testfile \
> +	       >> $seqres.full 2>&1
> +	[[ $? != 0 ]] && break
> +done
> +
> +echo "Verify \$testfile's extent count"
> +
> +nextents=$(xfs_get_fsxattr nextents $testfile)
> +if (( $nextents > 10 )); then
> +	echo "Extent count overflow check failed: nextents = $nextents"
> +	exit 1
> +fi
> +
> +rm $testfile
> +
> +echo "* Fallocate unwritten extents"
> +
> +echo "Fallocate fragmented file"
> +for i in $(seq 0 2 $((nr_blks - 1))); do
> +	$XFS_IO_PROG -f -c "falloc $((i * bsize)) $bsize" $testfile \
> +	       >> $seqres.full 2>&1
> +	[[ $? != 0 ]] && break
> +done
> +
> +echo "Verify \$testfile's extent count"
> +
> +nextents=$(xfs_get_fsxattr nextents $testfile)
> +if (( $nextents > 10 )); then
> +	echo "Extent count overflow check failed: nextents = $nextents"
> +	exit 1
> +fi
> +
> +rm $testfile
> +
> +echo "* Directio write"
> +
> +echo "Create fragmented file via directio writes"
> +for i in $(seq 0 2 $((nr_blks - 1))); do
> +	$XFS_IO_PROG -d -s -f -c "pwrite $((i * bsize)) $bsize" $testfile \
> +	       >> $seqres.full 2>&1
> +	[[ $? != 0 ]] && break
> +done
> +
> +echo "Verify \$testfile's extent count"
> +
> +nextents=$(xfs_get_fsxattr nextents $testfile)
> +if (( $nextents > 10 )); then
> +	echo "Extent count overflow check failed: nextents = $nextents"
> +	exit 1
> +fi
> +
> +rm $testfile
> +
> +# Check if XFS gracefully returns with an error code when we try to increase
> +# extent count of user quota inode beyond the pseudo max extent count limit.
> +echo "* Extend quota inodes"
> +
> +echo "Disable reduce_max_iextents error tag"
> +_scratch_inject_error reduce_max_iextents 0
> +
> +echo "Consume free space"
> +fillerdir=$SCRATCH_MNT/fillerdir
> +nr_free_blks=$(stat -f -c '%f' $SCRATCH_MNT)
> +nr_free_blks=$((nr_free_blks * 90 / 100))
> +
> +_fill_fs $((bsize * nr_free_blks)) $fillerdir $bsize 0 >> $seqres.full 2>&1
> +
> +echo "Create fragmented filesystem"
> +for dentry in $(ls -1 $fillerdir/); do
> +	$here/src/punch-alternating $fillerdir/$dentry >> $seqres.full
> +done
> +
> +echo "Inject reduce_max_iextents error tag"
> +_scratch_inject_error reduce_max_iextents 1
> +
> +echo "Inject bmap_alloc_minlen_extent error tag"
> +_scratch_inject_error bmap_alloc_minlen_extent 1
> +
> +nr_blks=20
> +
> +# This is a rough calculation; It doesn't take block headers into
> +# consideration.
> +# gdb -batch vmlinux -ex 'print sizeof(struct xfs_dqblk)'
> +# $1 = 136
> +nr_quotas_per_block=$((bsize / 136))
> +nr_quotas=$((nr_quotas_per_block * nr_blks))
> +
> +echo "Extend uquota file"
> +for i in $(seq 0 $nr_quotas_per_block $nr_quotas); do
> +	chown $i $testfile >> $seqres.full 2>&1
> +	[[ $? != 0 ]] && break
> +done
> +
> +_scratch_unmount >> $seqres.full
> +
> +echo "Verify uquota inode's extent count"
> +uquotino=$(_scratch_xfs_get_metadata_field 'uquotino' 'sb 0')
> +
> +nextents=$(_scratch_get_iext_count $uquotino data || \
> +		   _fail "Unable to obtain inode fork's extent count")
> +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/528.out b/tests/xfs/528.out
> new file mode 100644
> index 00000000..3973cc15
> --- /dev/null
> +++ b/tests/xfs/528.out
> @@ -0,0 +1,20 @@
> +QA output created by 528
> +Format and mount fs
> +* Delalloc to written extent conversion
> +Inject reduce_max_iextents error tag
> +Create fragmented file
> +Verify $testfile's extent count
> +* Fallocate unwritten extents
> +Fallocate fragmented file
> +Verify $testfile's extent count
> +* Directio write
> +Create fragmented file via directio writes
> +Verify $testfile's extent count
> +* Extend quota inodes
> +Disable reduce_max_iextents error tag
> +Consume free space
> +Create fragmented filesystem
> +Inject reduce_max_iextents error tag
> +Inject bmap_alloc_minlen_extent error tag
> +Extend uquota file
> +Verify uquota inode's extent count
> diff --git a/tests/xfs/group b/tests/xfs/group
> index e861cec9..2356c4a9 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -525,3 +525,4 @@
>  525 auto quick mkfs
>  526 auto quick mkfs
>  527 auto quick quota
> +528 auto quick quota
> -- 
> 2.29.2
>