Re: [PATCH V4 03/11] xfs: Check for extent overflow when growing realtime bitmap/summary inodes

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

On Mon, Jan 18, 2021 at 11:50:14AM +0530, Chandan Babu R wrote:
> Verify that XFS does not cause realtime bitmap/summary inode fork's
> extent count to overflow when growing the realtime volume associated
> with a filesystem.
> 
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> ---
>  tests/xfs/523     | 119 ++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/523.out |  11 +++++
>  tests/xfs/group   |   1 +
>  3 files changed, 131 insertions(+)
>  create mode 100755 tests/xfs/523
>  create mode 100644 tests/xfs/523.out
> 
> diff --git a/tests/xfs/523 b/tests/xfs/523
> new file mode 100755
> index 00000000..145f0ff6
> --- /dev/null
> +++ b/tests/xfs/523
> @@ -0,0 +1,119 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020 Chandan Babu R.  All Rights Reserved.
> +#
> +# FS QA Test 523
> +#
> +# Verify that XFS does not cause bitmap/summary inode fork's extent count to
> +# overflow when growing an the realtime volume of the filesystem.
> +#
> +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 /
> +	_scratch_unmount >> $seqres.full 2>&1
> +	test -e "$rtdev" && losetup -d $rtdev >> $seqres.full 2>&1
> +	rm -f $tmp.* $TEST_DIR/$seq.rtvol
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/inject
> +. ./common/populate
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +_supported_fs xfs
> +_require_test
> +_require_xfs_debug
> +_require_test_program "punch-alternating"
> +_require_xfs_io_error_injection "reduce_max_iextents"
> +_require_xfs_io_error_injection "bmap_alloc_minlen_extent"
> +_require_scratch_nocheck

Might want a comment about why this test doesn't _require_realtime.

Hm.  What /does/ happen if the kernel xfs driver wasn't built with
realtime support?  I'll investigate and report back.

> +
> +echo "* Test extending rt inodes"
> +
> +_scratch_mkfs | _filter_mkfs >> $seqres.full 2> $tmp.mkfs
> +. $tmp.mkfs
> +
> +echo "Create fake rt volume"
> +nr_bitmap_blks=25
> +nr_bits=$((nr_bitmap_blks * dbsize * 8))
> +rtextsz=$dbsize
> +rtdevsz=$((nr_bits * rtextsz))
> +truncate -s $rtdevsz $TEST_DIR/$seq.rtvol
> +rtdev=$(_create_loop_device $TEST_DIR/$seq.rtvol)
> +
> +echo "Format and mount rt volume"
> +
> +export USE_EXTERNAL=yes
> +export SCRATCH_RTDEV=$rtdev
> +_scratch_mkfs -d size=$((1024 * 1024 * 1024)) \
> +	      -r size=2M,extsize=${rtextsz} >> $seqres.full
> +_scratch_mount >> $seqres.full
> +
> +echo "Consume free space"
> +fillerdir=$SCRATCH_MNT/fillerdir
> +nr_free_blks=$(stat -f -c '%f' $SCRATCH_MNT)
> +nr_free_blks=$((nr_free_blks * 90 / 100))
> +
> +_fill_fs $((dbsize * nr_free_blks)) $fillerdir $dbsize 0 >> $seqres.full 2>&1
> +
> +echo "Create fragmented filesystem"
> +for dentry in $(ls -1 $fillerdir/); do
> +	$here/src/punch-alternating $fillerdir/$dentry >> $seqres.full
> +done
> +
> +echo "Inject reduce_max_iextents error tag"
> +_scratch_inject_error reduce_max_iextents 1
> +
> +echo "Inject bmap_alloc_minlen_extent error tag"
> +_scratch_inject_error bmap_alloc_minlen_extent 1
> +
> +echo "Grow realtime volume"
> +$XFS_GROWFS_PROG -r $SCRATCH_MNT >> $seqres.full 2>&1
> +if [[ $? == 0 ]]; then
> +	echo "Growfs succeeded; should have failed."
> +	exit 1
> +fi
> +
> +_scratch_unmount >> $seqres.full
> +
> +echo "Verify rbmino's and rsumino's extent count"
> +for rtino in rbmino rsumino; do
> +	ino=$(_scratch_xfs_db -c sb -c "print $rtino")
> +	ino=${ino##${rtino} = }
> +	echo "$rtino = $ino" >> $seqres.full
> +
> +	nextents=$(_scratch_get_iext_count $ino 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
> +done
> +
> +echo "Check filesystem"
> +_check_xfs_filesystem $SCRATCH_DEV none $rtdev
> +
> +losetup -d $rtdev
> +rm -f $TEST_DIR/$seq.rtvol
> +
> +export USE_EXTERNAL=""
> +export SCRATCH_RTDEV=""

No need to clear these, but with those two nits fixed, this looks all right.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/523.out b/tests/xfs/523.out
> new file mode 100644
> index 00000000..7df02970
> --- /dev/null
> +++ b/tests/xfs/523.out
> @@ -0,0 +1,11 @@
> +QA output created by 523
> +* Test extending rt inodes
> +Create fake rt volume
> +Format and mount rt volume
> +Consume free space
> +Create fragmented filesystem
> +Inject reduce_max_iextents error tag
> +Inject bmap_alloc_minlen_extent error tag
> +Grow realtime volume
> +Verify rbmino's and rsumino's extent count
> +Check filesystem
> diff --git a/tests/xfs/group b/tests/xfs/group
> index 1831f0b5..018c70ef 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -520,3 +520,4 @@
>  520 auto quick reflink
>  521 auto quick realtime growfs
>  522 auto quick quota
> +523 auto quick realtime growfs
> -- 
> 2.29.2
>