#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# FS QA Test No. 661
#
# Ensuring that copy on write in mmap mode works when the CoW
# range originally covers multiple extents, some delalloc, some not.
# (MMAP version of generic/195,194)
#   - Create a file.
#   - Reflink the odd blocks of the first file into the second file.
#   - Buffered write the even blocks of the second file.
#   - mmap CoW across the halfway mark, starting with the unwritten extent.
#   - Check that the files are now different where we say they're different.
#
. ./common/preamble
_begin_fstest auto quick clone prealloc

# Import common functions.
. ./common/filter
. ./common/reflink

# real QA test starts here
_require_scratch_reflink
_require_scratch_delalloc
_require_xfs_io_command "falloc"

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))
_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 "mmap CoW across the transition"
cowoff=$((filesize / 4))
cowsz=$((filesize / 2))
_weave_reflink_holes_delalloc $blksz $nr $testdir/file3 >> $seqres.full
mmapsz=$((cowoff + cowsz))
_mwrite_byte 0x63 $cowoff $cowsz $mmapsz $testdir/file3 >> $seqres.full
_mwrite_byte 0x63 $cowoff $cowsz $mmapsz $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

# success, all done
status=0
exit