#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2011 STRATO.  All rights reserved.
#
# FSQA Test No. btrfs/004
#
# Run fsstress to create a reasonably strange file system, make a
# snapshot and run more fsstress. Then select some files from that fs,
# run filefrag to get the extent mapping and follow the backrefs.
# We check to end up back at the original file with the correct offset.
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

here=`pwd`
tmp=/tmp/$$
status=1
noise_pid=0

_cleanup()
{
	rm $tmp.running
	wait
	rm -f $tmp.*
}
trap "_cleanup; exit \$status" 0 1 2 3 15

# get standard environment, filters and checks
. ./common/rc
. ./common/filter

# real QA test starts here
_supported_fs btrfs
_require_scratch
_require_no_large_scratch_dev
_require_btrfs_command inspect-internal logical-resolve
_require_btrfs_command inspect-internal inode-resolve
_require_command "$FILEFRAG_PROG" filefrag

rm -f $seqres.full

FILEFRAG_FILTER='
	if (/blocks? of (\d+) bytes/) {
		$blocksize = $1;
		next
	}
	($ext, $logical, $physical, $length) =
		(/^\s*(\d+):\s+(\d+)..\s+\d+:\s+(\d+)..\s+\d+:\s+(\d+):/)
	or next;
	($flags) = /.*:\s*(\S*)$/;
	print $physical * $blocksize, "#",
	      $length * $blocksize, "#",
	      $logical * $blocksize, "#",
	      $flags, " "'

# this makes filefrag output script readable by using a perl helper.
# output is one extent per line, with three numbers separated by '#'
# the numbers are: physical, length, logical (all in bytes)
# sample output: "1234#10#5678" -> physical 1234, length 10, logical 5678
_filter_extents()
{
	tee -a $seqres.full | $PERL_PROG -ne "$FILEFRAG_FILTER"
}

_check_file_extents()
{
	cmd="$FILEFRAG_PROG -v $1"
	echo "# $cmd" >> $seqres.full
	out=`$cmd | _filter_extents`
	if [ -z "$out" ]; then
		return 1
	fi
	echo "after filter: $out" >> $seqres.full
	echo $out
	return 0
}

# use a logical address and walk the backrefs back to the inode.
# compare to the expected result.
# returns 0 on success, 1 on error (with output made)
_btrfs_inspect_addr()
{
	mp=$1
	addr=$2
	expect_addr=$3
	expect_inum=$4
	file=$5
	cmd="$BTRFS_UTIL_PROG inspect-internal logical-resolve -s 65536 -P $addr $mp"
	echo "# $cmd" >> $seqres.full
	out=`$cmd`
	echo "$out" >> $seqres.full
	grep_expr="inode $expect_inum offset $expect_addr root"
	echo "$out" | grep "^$grep_expr 5$" >/dev/null
	ret=$?
	if [ $ret -eq 0 ]; then
		# look for a root number that is not 5
		echo "$out" | grep "^$grep_expr \([0-46-9][0-9]*\|5[0-9]\+\)$" \
			>/dev/null
		ret=$?
	fi
	if [ $ret -eq 0 ]; then
		return 0
	fi
	echo "unexpected output from"
	echo "	$cmd"
	echo "expected inum: $expect_inum, expected address: $expect_addr,"\
		"file: $file, got:"
	echo "$out"
	return 1
}

# use an inode number and walk the backrefs back to the file name.
# compare to the expected result.
# returns 0 on success, 1 on error (with output made)
_btrfs_inspect_inum()
{
	file=$1
	inum=$2
	snap_name=$3
	mp="$SCRATCH_MNT/$snap_name"
	cmd="$BTRFS_UTIL_PROG inspect-internal inode-resolve $inum $mp"
	echo "# $cmd" >> $seqres.full
	out=`$cmd`
	echo "$out" >> $seqres.full
	grep_expr="^$file$"
	cnt=`echo "$out" | grep "$grep_expr" | wc -l`
	if [ $cnt -ge "1" ]; then
		return 0
	fi
	echo "unexpected output from"
	echo "	$cmd"
	echo "expected path: $file, got:"
	echo "$out"
	return 1
}

_btrfs_inspect_check()
{
	file=$1
	physical=$2
	length=$3
	logical=$4
	snap_name=$5
	cmd="stat -c %i $file"
	echo "# $cmd" >> $seqres.full
	inum=`$cmd`
	echo "$inum" >> $seqres.full
	_btrfs_inspect_addr $SCRATCH_MNT $physical $logical $inum $file
	ret=$?
	if [ $ret -eq 0 ]; then
		_btrfs_inspect_inum $file $inum $snap_name
		ret=$?
	fi
	return $ret
}

workout()
{
	fsz=$1
	nfiles=$2
	procs=$3
	snap_name=$4
	do_bg_noise=$5

	_scratch_unmount >/dev/null 2>&1
	echo "*** mkfs -dsize=$fsz"    >>$seqres.full
	echo ""                                     >>$seqres.full
	_scratch_mkfs_sized $fsz >>$seqres.full 2>&1 \
		|| _fail "size=$fsz mkfs failed"
	_scratch_mount
	# -w ensures that the only ops are ones which cause write I/O
	run_check $FSSTRESS_PROG -d $SCRATCH_MNT -w -p $procs -n 2000 \
		$FSSTRESS_AVOID

	_run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT \
		$SCRATCH_MNT/$snap_name

	run_check _scratch_unmount >/dev/null 2>&1
	_scratch_mount "-o compress=lzo"

	# make some noise but ensure we're not touching existing data
	# extents.
	run_check $FSSTRESS_PROG -d $SCRATCH_MNT -p $procs -n 4000 \
		-z -f chown=3 -f link=1 -f mkdir=2 -f mknod=2 \
		-f rename=2 -f setxattr=1 -f symlink=2

	clean_dir="$SCRATCH_MNT/next"
	mkdir $clean_dir
	# now make more files to get a higher tree
	run_check $FSSTRESS_PROG -d $clean_dir -w -p $procs -n 2000 \
		$FSSTRESS_AVOID
	run_check _scratch_unmount >/dev/null 2>&1
	_scratch_mount "-o atime"

	if [ $do_bg_noise -ne 0 ]; then
		# make background noise while backrefs are being walked
		while [ -f "$tmp.running" ]; do
			echo background fsstress >>$seqres.full
			run_check $FSSTRESS_PROG -d $SCRATCH_MNT/bgnoise -n 999
			echo background rm >>$seqres.full
			rm -rf $SCRATCH_MNT/bgnoise/
		done &
		noise_pid=`jobs -p %1`
		echo "background noise by $noise_pid" >>$seqres.full
	fi

	cnt=0
	errcnt=0
	dir="$SCRATCH_MNT/$snap_name/"
	for file in `find $dir -name f\* -size +0 | sort -R`; do
		extents=`_check_file_extents $file`
		ret=$?
		if [ $ret -ne 0 ]; then
			continue;
		fi
		for i in $extents; do
			physical=`echo $i | cut -d '#' -f 1`
			length=`echo $i | cut -d '#' -f 2`
			logical=`echo $i | cut -d '#' -f 3`
			flags=`echo $i | cut -d '#' -f 4`
			# Skip inline extents, otherwise btrfs inspect-internal
			# logical-resolve will fail (with errno ENOENT), as it
			# can't find an extent with a start address of 0 in the
			# extent tree.
			if [ $physical -eq 0 ]; then
				echo "$flags" | grep -E '(^|,)inline(,|$)' \
					> /dev/null
				ret=$?
				if [ $ret -ne 0 ]; then
					echo "Unexpected physical address 0 for non-inline extent, file $file, flags $flags"
				fi
			else
				_btrfs_inspect_check $file $physical $length \
					$logical $snap_name
				ret=$?
			fi
			if [ $ret -ne 0 ]; then
				errcnt=`expr $errcnt + 1`
			fi
		done
		cnt=`expr $cnt + 1`
		if [ $cnt -ge $nfiles ]; then
			break
		fi
	done

	if [ $errcnt -gt 0 ]; then
		_fail "test failed: $errcnt error(s)"
	fi
}

echo "*** test backref walking"

snap_name="snap1"
filesize=`expr 2000 \* 1024 \* 1024`
nfiles=4
numprocs=1
do_bg_noise=1

touch $tmp.running

workout $filesize $nfiles $numprocs $snap_name $do_bg_noise

echo "*** done"
status=0
exit