#! /bin/bash
# FS QA Test No. 307
#
# Test recovery of "lost" CoW blocks:
# - Use the debugger to fake a leftover CoW extent
# - See if xfs_repair fixes it
#
#-----------------------------------------------------------------------
# Copyright (c) 2016, Oracle and/or its affiliates.  All Rights Reserved.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#-----------------------------------------------------------------------

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 -rf $tmp.*
}

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

# real QA test starts here
_supported_os Linux
_supported_fs xfs
_require_scratch_reflink

rm -f $seqres.full

echo "Format"
_scratch_mkfs > $seqres.full 2>&1
_scratch_mount >> $seqres.full
is_rmap=$(xfs_info $SCRATCH_MNT | grep -c "rmapbt=1")
_scratch_unmount

_get_agf_data() {
	field="$1"
	shift

	xfs_db -c 'agf 1' "$@" -c "p $field" $SCRATCH_DEV | awk '{print $3}'
}

_set_agf_data() {
	field="$1"
	value="$2"
	shift; shift

	xfs_db -x -c 'agf 1' "$@" -c "write $field -- $value" $SCRATCH_DEV >> $seqres.full
}

_get_sb_data() {
	field="$1"
	shift

	xfs_db -c 'sb 0' "$@" -c "p $field" $SCRATCH_DEV | awk '{print $3}'
}

_set_sb_data() {
	field="$1"
	value="$2"
	shift; shift

	xfs_db -x -c 'sb 0' "$@" -c "write $field -- $value" $SCRATCH_DEV >> $seqres.full
}

_filter_leftover() {
	grep "^leftover" | sed -e "s/[0-9]\+/NR/g"
}

_dump_status() {
	echo "** " "$@"
	xfs_db -c 'sb 0' -c p $SCRATCH_DEV
	echo "** agf header"
	xfs_db -c 'agf 1' -c p $SCRATCH_DEV
	echo "** refcntbt"
	xfs_db -c 'agf 1' -c 'addr refcntroot' -c p $SCRATCH_DEV
	echo "** rmapbt"
	test $is_rmap -gt 0 && xfs_db -c 'agf 1' -c 'addr rmaproot' -c p $SCRATCH_DEV
	echo "** bnobt"
	xfs_db -c 'agf 1' -c 'addr bnoroot' -c p $SCRATCH_DEV
	echo "** cntbt"
	xfs_db -c 'agf 1' -c 'addr cntroot' -c p $SCRATCH_DEV
}

echo "We need AG1 to have a single free extent"
bno_lvl=$(_get_agf_data level -c 'addr bnoroot')
bno_nr=$(_get_agf_data numrecs -c 'addr bnoroot')
refc_lvl=$(_get_agf_data level -c 'addr refcntroot')
refc_nr=$(_get_agf_data numrecs -c 'addr refcntroot')

test $bno_lvl -eq 0 || echo "  AG 1 bnobt must only have one level"
test $bno_nr -eq 1 || echo "  AG 1 bnobt must only have one record"
test $refc_lvl -eq 0 || echo "  AG 1 refcountbt must only have one level"
test $refc_nr -eq 0 || echo "  AG 1 refcountbt must only have one record"

if [ $is_rmap -gt 0 ]; then
	rmap_lvl=$(_get_agf_data level -c 'addr rmaproot')
	rmap_nr=$(_get_agf_data numrecs -c 'addr rmaproot')
	test $rmap_lvl -eq 0 || echo "  AG 1 rmapbt must only have one level"
fi

echo "Find our extent and old counter values"
bno=$(_get_agf_data "recs[1].startblock" -c 'addr bnoroot')
len=$(_get_agf_data "recs[1].blockcount" -c 'addr bnoroot')
agf_freeblks=$(_get_agf_data freeblks)
sb_fdblocks=$(_get_sb_data fdblocks)

test $len -ge 200 || echo "  AG 1 doesn't have enough free blocks"

# Take the last 100 blocks of the free extent
debris_len=100
debris_bno=$((bno + len - debris_len))

echo "Remove the extent from the freesp btrees"
_set_agf_data "recs[1].blockcount" $((len - debris_len)) -c 'addr bnoroot'
_set_agf_data "recs[1].blockcount" $((len - debris_len)) -c 'addr cntroot'
_set_agf_data freeblks $((agf_freeblks - debris_len))
_set_agf_data longest $((len - debris_len))
_set_sb_data fdblocks $((sb_fdblocks - debris_len))

echo "Add the extent to the refcount btree"
_set_agf_data numrecs 1 -c 'addr refcntroot'
_set_agf_data "recs[1].startblock" $debris_bno -c 'addr refcntroot'
_set_agf_data "recs[1].blockcount" $debris_len -c 'addr refcntroot'
_set_agf_data "recs[1].refcount" 1 -c 'addr refcntroot'

if [ $is_rmap -gt 0 ]; then
	rmap_nr=$((rmap_nr + 1))
	_set_agf_data numrecs $rmap_nr -c 'addr rmaproot'
	_set_agf_data "recs[$rmap_nr].startblock" $debris_bno -c 'addr rmaproot'
	_set_agf_data "recs[$rmap_nr].blockcount" $debris_len -c 'addr rmaproot'
	_set_agf_data "recs[$rmap_nr].owner" -9 -c 'addr rmaproot'
	_set_agf_data "recs[$rmap_nr].offset" 0 -c 'addr rmaproot'
fi

_dump_status "broken fs config" >> $seqres.full

echo "Look for leftover warning in xfs_check"
_scratch_xfs_check | _filter_leftover

echo "Look for leftover warning in xfs_repair"
_scratch_xfs_repair -n 2>&1 | _filter_leftover

echo "Fix filesystem"
_scratch_xfs_repair >> $seqres.full 2>&1 || echo "xfs_repair failed?"

_dump_status "supposedly fixed fs config" >> $seqres.full

echo "Look for no more leftover warning in xfs_check"
_scratch_xfs_check | _filter_leftover

echo "Look for no more leftover warning in xfs_repair"
_scratch_xfs_repair -n 2>&1 | _filter_leftover

# success, all done
status=0
exit
