#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2018 Facebook.  All Rights Reserved.
#
# FS QA Test 177
#
# Test relocation (balance and resize) with an active swap file.
#
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 -f $tmp.*
}

. ./common/rc
. ./common/filter
. ./common/btrfs

rm -f $seqres.full

# Modify as appropriate.
_supported_fs btrfs
_require_scratch_swapfile

swapfile="$SCRATCH_MNT/swap"

_require_scratch_size $((3 * 1024 * 1024)) #kB

# First, create a 1GB filesystem.
fssize=$((1024 * 1024 * 1024))
_scratch_mkfs_sized $fssize >> $seqres.full 2>&1
_scratch_mount

# Create a small file and run balance so we shall deal with the chunk
# size as allocated by the kernel, mkfs allocated chunks are smaller.
dd if=/dev/zero of="$SCRATCH_MNT/fill" bs=4096 count=1 >> $seqres.full 2>&1
_run_btrfs_balance_start "$SCRATCH_MNT" >>$seqres.full

# Now fill it up.
dd if=/dev/zero of="$SCRATCH_MNT/refill" bs=4096 >> $seqres.full 2>&1

# Now add more space and create a swap file. We know that the first $fssize
# of the filesystem was used, so the swap file must be in the new part of the
# filesystem.
$BTRFS_UTIL_PROG filesystem resize $((3 * fssize)) "$SCRATCH_MNT" | \
							_filter_scratch
_format_swapfile "$swapfile" $((32 * 1024 * 1024))
swapon "$swapfile"

# Free up the first 1GB of the filesystem.
rm -f "$SCRATCH_MNT/fill"
rm -f "$SCRATCH_MNT/refill"

# Get rid of empty block groups and also make sure that balance skips block
# groups containing active swap files.
_run_btrfs_balance_start "$SCRATCH_MNT" >>$seqres.full

# Try to shrink away the area occupied by the swap file, which should fail.
$BTRFS_UTIL_PROG filesystem resize 1G "$SCRATCH_MNT" 2>&1 | grep -o "Text file busy"

swapoff "$swapfile"

# It should work again after swapoff.
$BTRFS_UTIL_PROG filesystem resize $fssize "$SCRATCH_MNT" | _filter_scratch

status=0
exit