#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2017 CTERA Networks. All Rights Reserved.
#
# FS QA Test 048
#
# Test nlink accounting of overlay hardlinks with offline modifications.
#
# nlink of overlay inode should account for the union of lower and upper
# hardlinks. Orphan index inodes with union nlink 0 should be cleaned on
# mount.
#
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

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

# real QA test starts here
_supported_fs overlay
_require_scratch
_require_scratch_feature index

report_nlink()
{
	when=$1

	# mount and check nlink after overlay offline modification
	_scratch_mount -o index=on

	# List <nlink> <name>
	echo "== $when offline =="
	for f in $HARDLINKS; do
		_ls_l $SCRATCH_MNT/$f | awk '{ print $2, $9 }' | _filter_scratch
	done

	$UMOUNT_PROG $SCRATCH_MNT
}

# Create lower hardlinks
create_hardlinks()
{
	mkdir -p $lowerdir
	touch $lowerdir/0
	ln $lowerdir/0 $lowerdir/1
	ln $lowerdir/0 $lowerdir/2
}

test_hardlinks_offline()
{
	HARDLINKS=`seq 0 2`
	report_nlink "all upper"

	# Unlink copied up hardlink
	rm $upperdir/0
	HARDLINKS=`seq 1 2`
	report_nlink "unlink upper"

	# Link to copied up hardlink
	ln $upperdir/2 $upperdir/3
	HARDLINKS=`seq 1 3`
	report_nlink "link upper"

	# Rename over copied up hardlink
	touch $upperdir/new
	mv $upperdir/new $upperdir/1
	HARDLINKS=`seq 2 3`
	report_nlink "rename over upper"

	# Unlink new upper hardlink
	rm $upperdir/3
	HARDLINKS=2
	report_nlink "unlink new upper"

	# Unlink last upper and drop union nlink to zero
	rm $upperdir/2

	HARDLINKS=
	report_nlink "unlink last lower"

	# Verify that orphan index is cleaned when dropping nlink to zero
	# With nfs_export=on index will contain a whiteout index entry, so allow
	# chardev entries in index dir.
	find $workdir/index -mindepth 1 -type c -o -print
}

lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
upperdir=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
workdir=$OVL_BASE_SCRATCH_MNT/$OVL_WORK

# Remove all files from previous tests
_scratch_mkfs

# Create lower hardlinks
create_hardlinks

# Enable overlay index feature to prevent breaking hardlinks on copy up
_scratch_mount -o index=on

# Copy up and index hardlinks
touch $SCRATCH_MNT/0
touch $SCRATCH_MNT/1
touch $SCRATCH_MNT/2

# Perform the rest of the changes offline
$UMOUNT_PROG $SCRATCH_MNT

test_hardlinks_offline

status=0
exit