#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2019 SUSE Linux Products GmbH. All Rights Reserved.
#
# FS QA Test 546
#
# Test when a fs is full we can still:
# - Do buffered write into a unpopulated preallocated extent
# - Clone the untouched part of that preallocated extent
# - Fsync
# - No data loss even power loss happens after fsync
# All operations above should not fail.
#
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()
{
	_cleanup_flakey
	cd /
	rm -f $tmp.*
}

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

# remove previous $seqres.full before test
rm -f $seqres.full

# real QA test starts here

# Modify as appropriate.
_supported_fs generic
_require_xfs_io_command "falloc"
_require_scratch_reflink
_require_dm_target flakey

_scratch_mkfs_sized $((512 * 1024 * 1024)) >> $seqres.full 2>&1
_require_metadata_journaling $SCRATCH_DEV
_init_flakey
_mount_flakey

# Create preallocated extent where we can write into
$XFS_IO_PROG -f -c 'falloc 8k 64m' "$SCRATCH_MNT/foobar" >> $seqres.full

# Use up all data space, to test later write-into-preallocate behavior
_pwrite_byte 0x00 0 512m "$SCRATCH_MNT/padding" >> $seqres.full 2>&1

# Sync to ensure that padding file reach disk so that at log recovery we
# still have no data space
sync

# This should not fail
_pwrite_byte 0xcd 1m 16m "$SCRATCH_MNT/foobar" >> $seqres.full

# Do reflink here, we shouldn't use extra data space, thus it should not fail
$XFS_IO_PROG -c "reflink ${SCRATCH_MNT}/foobar 8k 0 4k" "$SCRATCH_MNT/foobar" \
	>> $seqres.full

# Checksum before power loss
echo md5 before $(_md5_checksum "$SCRATCH_MNT/foobar")

# Fsync to check if writeback is ok
$XFS_IO_PROG -c 'fsync'  "$SCRATCH_MNT/foobar"

# Now emulate power loss
_flakey_drop_and_remount

# Checksum after power loss
echo md5 after $(_md5_checksum "$SCRATCH_MNT/foobar")

# success, all done
status=0
exit