#! /bin/bash
# FS QA Test No. 138
#
# Ensuring that copy on write through the page cache works:
#   - Reflink two files together
#   - Write to the beginning, middle, and end
#   - Check that the files are now different where we say they're different.
#
#-----------------------------------------------------------------------
# Copyright (c) 2015, 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.* $testdir
}

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

# real QA test starts here
_supported_os Linux
_require_test_reflink
_require_cp_reflink

rm -f $seqres.full

testdir=$TEST_DIR/test-$seq
rm -rf $testdir
mkdir $testdir

echo "Create the original files"
blksz=65536
_pwrite_byte 0x61 0 $((blksz * 48 - 3)) $testdir/file1 >> $seqres.full
_cp_reflink $testdir/file1 $testdir/file2 >> $seqres.full
_pwrite_byte 0x61 0 $((blksz * 48 - 3)) $testdir/file3 >> $seqres.full
_test_cycle_mount

echo "Compare files"
md5sum $testdir/file1 | _filter_test_dir
md5sum $testdir/file2 | _filter_test_dir
md5sum $testdir/file3 | _filter_test_dir

cmp -s $testdir/file1 $testdir/file2 || echo "Files 1-2 do not match"
cmp -s $testdir/file1 $testdir/file3 || echo "Files 1-3 do not match"
cmp -s $testdir/file2 $testdir/file3 || echo "Files 2-3 do not match"

echo "pagecache CoW the second file"
_pwrite_byte 0x62 0 17 $testdir/file2 >> $seqres.full
_pwrite_byte 0x62 0 17 $testdir/file3 >> $seqres.full

_pwrite_byte 0x62 $((blksz * 16 - 34)) 17 $testdir/file2 >> $seqres.full
_pwrite_byte 0x62 $((blksz * 16 - 34)) 17 $testdir/file3 >> $seqres.full

_pwrite_byte 0x62 $((blksz * 48 - 8)) 17 $testdir/file2 >> $seqres.full
_pwrite_byte 0x62 $((blksz * 48 - 8)) 17 $testdir/file3 >> $seqres.full
_test_cycle_mount

echo "Compare files"
md5sum $testdir/file1 | _filter_test_dir
md5sum $testdir/file2 | _filter_test_dir
md5sum $testdir/file3 | _filter_test_dir

cmp -s $testdir/file1 $testdir/file2 || echo "Files 1-2 do not match (intentional)"
cmp -s $testdir/file1 $testdir/file3 || echo "Files 1-3 do not match (intentional)"
cmp -s $testdir/file2 $testdir/file3 || echo "Files 2-3 do not match"

echo "Compare the CoW'd section to the before file"
_compare_range $testdir/file1 0 $testdir/file2 0 17 \
       || echo "Start sections do not match (intentional)"

_compare_range  $testdir/file1 $((blksz * 16 - 34)) \
		$testdir/file2 $((blksz * 16 - 34)) 17 \
       || echo "Middle sections do not match (intentional)"

_compare_range  $testdir/file1 $((blksz * 48 - 8)) \
		$testdir/file2 $((blksz * 48 - 8)) 17 \
       || echo "End sections do not match (intentional)"

echo "Compare the CoW'd section to the after file"
_compare_range $testdir/file2 0 $testdir/file3 0 17 \
       || echo "Start sections do not match"

_compare_range  $testdir/file2 $((blksz * 16 - 34)) \
		$testdir/file3 $((blksz * 16 - 34)) 17 \
       || echo "Middle sections do not match"

_compare_range  $testdir/file2 $((blksz * 48 - 8)) \
		$testdir/file3 $((blksz * 48 - 8)) 17 \
       || echo "End sections do not match"

echo "Compare the not CoW'd sections"
_compare_range $testdir/file1 18 $testdir/file2 18 17 \
       || echo "Start sections of 1-2 do not match"

_compare_range $testdir/file2 18 $testdir/file3 18 17 \
       || echo "Start sections of 2-3 do not match"


_compare_range  $testdir/file1 $((blksz * 16 - 17)) \
		$testdir/file2 $((blksz * 16 - 17)) 82 \
       || echo "Middle sections of 1-2 do not match"

_compare_range  $testdir/file2 $((blksz * 16 - 17)) \
		$testdir/file3 $((blksz * 16 - 17)) 82 \
       || echo "Middle sections of 2-3 do not match"

_compare_range  $testdir/file1 $((blksz * 48 - 108)) \
		$testdir/file2 $((blksz * 48 - 108)) 100 \
       || echo "End sections of 1-2 do not match"

_compare_range  $testdir/file2 $((blksz * 48 - 108)) \
		$testdir/file3 $((blksz * 48 - 108)) 100 \
       || echo "End sections of 2-3 do not match"


_compare_range  $testdir/file1 $((blksz * 14)) \
		$testdir/file2 $((blksz * 14)) $blksz \
       || echo "Untouched sections of 1-2 do not match"

_compare_range  $testdir/file2 $((blksz * 14)) \
		$testdir/file3 $((blksz * 14)) $blksz \
       || echo "Untouched sections of 2-3 do not match"

# success, all done
status=0
exit
