apfstests/tests/generic/142

#! /bin/bash
# FS QA Test No. 142
#
# Ensure that reflinking a file N times and CoWing the copies leaves the
# original intact.
#   - Create a file and record its hash
#   - Create some reflink copies
#   - Rewrite all the reflink copies
#   - Compare the contents of the original file
#
#-----------------------------------------------------------------------
# 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 file blocks"
blksz=65536
nr=9
_pwrite_byte 0x61 0 $((blksz * 256)) "$testdir/file1" >> "$seqres.full"
_test_remount

md5sum "$testdir/file1" | _filter_test_dir
csum="$(_md5_checksum "$testdir/file1")"

echo "Create the reflink copies"
seq 2 $nr | while read i; do
	_cp_reflink "$testdir/file1" "$testdir/file$i"
done
_test_remount

echo "Rewrite the copies"
seq 2 $nr | while read i; do
	_pwrite_byte 0x62 0 $((blksz * 256)) "$testdir/file$i" >> "$seqres.full"
done
_test_remount

echo "Examine original file"
md5sum "$testdir/file1" | _filter_test_dir
md5sum "$testdir/file2" | _filter_test_dir

mod_csum="$(_md5_checksum "$testdir/file2")"
new_csum="$(_md5_checksum "$testdir/file1")"
test "${csum}" != "${mod_csum}" || echo "checksums do not match"
test "${csum}" = "${new_csum}" || echo "checksums do not match"

# success, all done
status=0
exit