#! /bin/bash
# FS QA Test No. 221
#
# Ensuring that copy on write in buffered mode works when the CoW
# range originally covers multiple extents, some holes, some not.
#   - Set cowextsize hint.
#   - Create a file and truncate a second file.
#   - Reflink the odd blocks of the first file into the second file.
#   - CoW across the halfway mark, starting with the unwritten extent.
#   - Check that the files are now different where we say they're different.
#
#-----------------------------------------------------------------------
# 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
_require_scratch_reflink
_require_xfs_io_command "falloc"
_require_xfs_io_command "cowextsize"

rm -f $seqres.full

echo "Format and mount"
_scratch_mkfs > $seqres.full 2>&1
_scratch_mount >> $seqres.full 2>&1

testdir=$SCRATCH_MNT/test-$seq
mkdir $testdir

echo "Create the original files"
blksz=65536
nr=64
filesize=$((blksz * nr))
real_blksz=$(stat -f -c '%S' $testdir)
internal_blks=$((filesize / real_blksz))
$XFS_IO_PROG -c "cowextsize $((blksz * 16))" $testdir >> $seqres.full
_weave_reflink_holes $blksz $nr $testdir/file1 $testdir/file3 >> $seqres.full
_scratch_cycle_mount

echo "Compare files"
md5sum $testdir/file1 | _filter_scratch
md5sum $testdir/file3 | _filter_scratch
md5sum $testdir/file3.chk | _filter_scratch

echo "CoW across the transition"
cowoff=$((filesize / 4))
cowsz=$((filesize / 2))
$XFS_IO_PROG -f -c "pwrite -S 0x63 -b $cowsz $cowoff $cowsz" $testdir/file3 >> $seqres.full
_pwrite_byte 0x63 $cowoff $cowsz $testdir/file3.chk >> $seqres.full
_scratch_cycle_mount

echo "Compare files"
md5sum $testdir/file1 | _filter_scratch
md5sum $testdir/file3 | _filter_scratch
md5sum $testdir/file3.chk | _filter_scratch

echo "Check extent counts"
old_extents=$(_count_extents $testdir/file1)
new_extents=$(_count_extents $testdir/file3)

echo "old extents: $old_extents" >> $seqres.full
echo "new extents: $new_extents" >> $seqres.full
echo "maximum extents: $internal_blks" >> $seqres.full
test $((new_extents - (nr / 4))) -lt $((internal_blks / 2)) || echo "file3 badly fragmented"

# success, all done
status=0
exit
