Re: [PATCH] generic: verify FIBMAP address overlap

[Eryu Guan <guaneryu@gmail.com>]

On Wed, Oct 24, 2018 at 05:23:56PM +0800, Zorro Lang wrote:
> xfstests doesn't cover FIBMAP test, it cause we brought in a
> regression bug fixed by "79b3dbe4adb3 fs: fix iomap_bmap position
> calculation".
> 
> Although FIBMAP is old, there're still some programs use it, likes
> LILO. This case tests if there's physical address overlap returned
> by FIBMAP.
> 
> Signed-off-by: Zorro Lang <zlang@redhat.com>
> ---
>  tests/generic/999     | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/999.out |   3 ++
>  tests/generic/group   |   1 +
>  3 files changed, 121 insertions(+)
>  create mode 100755 tests/generic/999
>  create mode 100644 tests/generic/999.out
> 
> diff --git a/tests/generic/999 b/tests/generic/999
> new file mode 100755
> index 00000000..3f70452d
> --- /dev/null
> +++ b/tests/generic/999
> @@ -0,0 +1,117 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2018 Red Hat Inc.  All Rights Reserved.
> +#
> +# FS QA Test No. 999
> +#
> +# Verify if there's physical address overlap returned by FIBMAP, cover:
> +# 79b3dbe4adb3 fs: fix iomap_bmap position calculation
> +#
> +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
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +_require_scratch
> +_require_command "$FILEFRAG_PROG" filefrag
> +
> +TESTFILE="$SCRATCH_MNT/$seq-testfile"

Use lower case name for local variables.

> +
> +# Use filefrag -B option to force the use of the older FIBMAP ioctl instead of
> +# the FIEMAP ioctl. Then verify if there's map overlap.
> +verify_filefrag()
> +{
> +	local n=1
> +
> +	# record details in .full file
> +	${FILEFRAG_PROG} -Bes -v $TESTFILE >> $seqres.full
> +
> +	# Due to physical things can't be golden image, so only output logical
> +	# information at here
> +	${FILEFRAG_PROG} -Be $TESTFILE | _filter_filefrag | \
> +		cut -d# -f1-2 > $tmp.filefrag
> +
> +	# Verify there's not physical address overlay
> +	for i in `cat $tmp.filefrag`; do
> +		# Get the start(v1) and end(v2) addresses will be verified
> +		v1=`sed -n "${n}p" $tmp.filefrag | cut -d# -f1`
> +		v2=`sed -n "${n}p" $tmp.filefrag | cut -d# -f2`
> +		# The 2nd value is length, so the real end addr is:
> +		v2=$((v1 + v2))
> +		# The end address maybe same with the next start address, so
> +		# reduce 1 at here
> +		((v2--))

I don't think this is needed, we just have the extent range as [v1, v2),
which v1 is inclusive and v2 is exclusive.

> +
> +		# Remove the line need to be verified ($i), compare with other
> +		# lines one by one
> +		sed -e "${n}d" $tmp.filefrag > $tmp.filefrag.tmp
> +		for j in `cat $tmp.filefrag.tmp`; do
> +			# Get 'next' line start(e1) and end(e2) addresses
> +			e1=`echo $j | cut -d# -f1`
> +			e2=`echo $j | cut -d# -f2`
> +			# The 2nd value is length, so the real end addr is:
> +			e2=$((e1 + e2))
> +			# Verify there's not:
> +			# [ e1 ... e2 ]
> +			#       [ v1 ... v2 ]
> +			if [ ${v1} -ge ${e1} -a ${v1} -le ${e2} ]; then
> +				echo "find physical addr overlap [$i] vs [$j]"
> +			fi
> +			# Verify there's not:
> +			#       [ e1 ... e2 ]
> +			# [ v1 ... v2 ]
> +			if [ ${v2} -ge ${e1} -a ${v2} -le ${e2} ]; then
> +				echo "find physical addr overlap [$i] vs [$j]"
> +			fi

So we only allow v1 >= e2 or e1 >= v2, otherwise we have a addr overlap.

> +		done
> +		((n++))
> +	done
> +}
> +
> +_scratch_mkfs > $seqres.full 2>&1
> +_scratch_mount
> +
> +# Check if FIBMAP is supported
> +echo "XX" > $TESTFILE
> +${FILEFRAG_PROG} -B $TESTFILE 2>&1 | \
> +	grep -q "FIBMAP[[:space:]]*unsupported"
> +if [ $? -eq 0 ]; then
> +	_notrun "FIBMAP isn't supported on current fs"
> +fi
> +rm -f $TESTFILE

Make it a new _require_fibmap() rule?

Thanks,
Eryu

> +
> +# Test
> +echo "== FIBMAP on empty file =="
> +$XFS_IO_PROG -f -c "truncate 0" $TESTFILE > /dev/null
> +verify_filefrag
> +
> +echo "== FIBMAP on sparse file =="
> +$XFS_IO_PROG -f -t -c "pwrite -S 0xaa 0 1m" \
> +	     -c "pwrite -S 0xaa 2m 1m" \
> +	     -c "pwrite -S 0xaa 4m 1m" \
> +	     $TESTFILE > /dev/null
> +verify_filefrag
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/generic/999.out b/tests/generic/999.out
> new file mode 100644
> index 00000000..d3edbccf
> --- /dev/null
> +++ b/tests/generic/999.out
> @@ -0,0 +1,3 @@
> +QA output created by 999
> +== FIBMAP on empty file ==
> +== FIBMAP on sparse file ==
> diff --git a/tests/generic/group b/tests/generic/group
> index 47de9782..45f1d534 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -519,3 +519,4 @@
>  514 auto quick clone
>  515 auto quick clone
>  516 auto quick dedupe clone
> +999 auto quick
> -- 
> 2.14.5
>