#! /bin/bash
# FS QA Test No. 298
#
# Test that filesystem sends discard requests only on free blocks
#
#-----------------------------------------------------------------------
# Copyright (c) 2013 Red Hat, Inc., Tomas Racek <tracek@redhat.com>
#
# 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`
echo "QA output created by $seq"

status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

. common.config
. common.rc

_supported_fs ext4 xfs
_supported_os Linux
_require_fstrim
_require_fs_space $TEST_DIR 307200
[ "$FSTYP" = "ext4" ] && _require_dumpe2fs

_cleanup()
{
	$UMOUNT_PROG $loop_dev &> /dev/null
	_destroy_loop_device $loop_dev
	if [ $status -eq 0 ]; then
		rm -rf $tmp
		rm $img_file
	fi
}

get_holes()
{
	$XFS_IO_PROG -c fiemap $1 | grep hole | $SED_PROG 's/.*\[\(.*\)\.\.\(.*\)\].*/\1 \2/'
}

get_free_sectors()
{
	case $FSTYP in
	ext4)
	$DUMPE2FS_PROG $img_file  2>&1 | grep " Free blocks" | cut -d ":" -f2- | \
		tr ',' '\n' | $SED_PROG 's/^ //' | \
		$AWK_PROG -v spb=$sectors_per_block 'BEGIN{FS="-"};
		     NF {
			if($2 != "") # range of blocks
				print spb * $1, spb * ($2 + 1) - 1;
			else		# just single block
				print spb * $1, spb * ($1 + 1) - 1;
		     }'
	;;
	xfs)
	agsize=`xfs_info $loop_mnt | $SED_PROG -n 's/.*agsize=\(.*\) blks.*/\1/p'`
	# Convert free space (agno, block, length) to (start sector, end sector)
	$UMOUNT_PROG $loop_mnt
	$XFS_DB_PROG -c "freesp -d" $img_file | $SED_PROG '/^.*from/,$d'| \
		 $AWK_PROG -v spb=$sectors_per_block -v agsize=$agsize \
		'{ print spb * ($1 * agsize + $2), spb * ($1 * agsize + $2 + $3) - 1 }'
	;;
	esac
}

merge_ranges()
{
	# Merges consecutive ranges from two input files
	file1=$1
	file2=$2

	tmp_file=$tmp/sectors.tmp

	cat $file1 $file2 | sort -n > $tmp_file

	read line < $tmp_file
	start=${line% *}
	end=${line#* }

	# Continue from second line
	sed -i "1d" $tmp_file
	while read line; do
		curr_start=${line% *}
		curr_end=${line#* }

		if [ `expr $end + 1` -ge $curr_start ]; then
			if [ $curr_end -gt $end ]; then
				end=$curr_end
			fi
		else
			echo $start $end
			start=$curr_start
			end=$curr_end
		fi
	done < $tmp_file

	# Print last line
	echo $start $end

	rm $tmp_file
}

here=`pwd`
tmp=`mktemp -d`

img_file=$TEST_DIR/$$.fs
dd if=/dev/zero of=$img_file bs=1M count=300 &> /dev/null

loop_dev=$(_create_loop_device $img_file)
loop_mnt=$tmp/loop_mnt

fiemap_ref="$tmp/reference"
fiemap_after="$tmp/after"
free_sectors="$tmp/free_sectors"
merged_sectors="$tmp/merged_free_sectors"

mkdir $loop_mnt

[ "$FSTYP" = "xfs" ] && MKFS_OPTIONS="-f $MKFS_OPTIONS"

$MKFS_PROG -t $FSTYP $MKFS_OPTIONS $loop_dev &> /dev/null
$MOUNT_PROG $loop_dev $loop_mnt

echo -n "Generating garbage on loop..."
for i in `seq 1 10`; do
	mkdir $loop_mnt/$i
	cp -r $here/* $loop_mnt/$i
done

# Get reference fiemap, this can contain i.e. uninitialized inode table
sync
get_holes $img_file > $fiemap_ref

# Delete some files
find $loop_mnt -type f -print | $AWK_PROG \
	'BEGIN {srand()}; {if(rand() > 0.7) print $1;}' | xargs rm
echo "done."

echo -n "Running fstrim..."
$FSTRIM_PROG $loop_mnt &> /dev/null
echo "done."

echo -n "Detecting interesting holes in image..."
# Get after-trim fiemap
sync
get_holes $img_file > $fiemap_after
echo "done."

echo -n "Comparing holes to the reported space from FS..."
# Get block size
block_size=$(stat -f -c "%S" $loop_mnt/)
sectors_per_block=`expr $block_size / 512`

# Obtain free space from filesystem
get_free_sectors > $free_sectors
# Merge original holes with free sectors
merge_ranges $fiemap_ref $free_sectors > $merged_sectors

# Check that all holes after fstrim call were already present before or
# that they match free space reported from FS
while read line; do
        from=${line% *}
        to=${line#* }
	if ! $AWK_PROG -v s=$from -v e=$to \
		'{ if ($1 <= s && e <= $2) found = 1};
		END { if(found) exit 0; else exit 1}' $merged_sectors
	then
		echo "Sectors $from-$to are not marked as free!"
		exit
	fi
done < $fiemap_after
echo "done."

status=0
exit