apfstests/tests/generic/562

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2019 SUSE Linux Products GmbH. All Rights Reserved.
#
# FSQA Test No. 562
#
# Test that if we clone a file with some large extents into a file that has
# many small extents, when the fs is nearly full, the clone operation does
# not fail and produces the correct result.
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
	cd /
	rm -f $tmp.*
}

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

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_scratch_reflink
_require_test_program "punch-alternating"
_require_xfs_io_command "fpunch"

rm -f $seqres.full

_scratch_mkfs_sized $((512 * 1024 * 1024)) >>$seqres.full 2>&1
_scratch_mount

file_size=$(( 200 * 1024 * 1024 )) # 200Mb

# Create a file with many small extents.
$XFS_IO_PROG -f -c "pwrite -S 0xe5 -b $file_size 0 $file_size" \
	$SCRATCH_MNT/foo >>/dev/null
$here/src/punch-alternating $SCRATCH_MNT/foo >> $seqres.full

# Create file bar with the same size that file foo has but with large extents.
$XFS_IO_PROG -f -c "pwrite -S 0xc7 -b $file_size 0 $file_size" \
	$SCRATCH_MNT/bar >>/dev/null

# Fill the fs (For btrfs we are interested in filling all unallocated space
# and most of the existing metadata block group(s), so that after this there
# will be no unallocated space and metadata space will be mostly full but with
# more than enough free space for the clone operation below to succeed, we
# create files with 2Kb because that results in extents inlined in the metadata
# (btree leafs) and it's the fastest way to fill metadata space on btrfs, by
# default btrfs inlines up to 2Kb of data).
i=1
while true; do
	$XFS_IO_PROG -f -c "pwrite 0 2K" $SCRATCH_MNT/filler_$i &> /dev/null
	[ $? -ne 0 ] && break
	i=$(( i + 1 ))
done

# Now clone file bar into file foo. This is supposed to succeed and not fail
# with ENOSPC for example.
_reflink $SCRATCH_MNT/bar $SCRATCH_MNT/foo >>$seqres.full

# Unmount and mount the filesystem again to verify the operation was durably
# persisted.
_scratch_cycle_mount

echo "File foo data after cloning and remount:"
od -A d -t x1 $SCRATCH_MNT/foo

status=0
exit