tests/f2fs/012

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2025 Chao Yu.  All Rights Reserved.
#
# FS QA Test No. f2fs/012
#
# This testcase checks whether linear lookup fallback works well
# or not as below:
# 1.create file w/ red heart as its filename
# 2.inject wrong hash code to the file
# 3.disable linear lookup, expect lookup failure
# 4.enable linear lookup, expect lookup succeed
#
. ./common/preamble
_begin_fstest auto quick casefold

_fixed_by_kernel_commit 91b587ba79e1 \
	"f2fs: Introduce linear search for dentries"

export LC_ALL=C.UTF-8
_require_scratch_nocheck
_require_command "$F2FS_IO_PROG" f2fs_io
_require_inject_f2fs_command dent d_hash

#check whether f2fs supports "lookup_mode=x" mount option
mntopt=""
_scratch_mkfs -O casefold -C utf8 >> $seqres.full
_try_scratch_mount "-o lookup_mode=auto" >> $seqres.full 2>&1
if [ $? == 0 ]; then
	mntopt="-o lookup_mode=auto"
	_scratch_unmount
fi

check_lookup()
{
	local nolinear_lookup=$1
	local dir=$SCRATCH_MNT/dir
	# red heart charactor in unicode format
	local redheart=$dir/$'\u2764\ufe0f'

	_scratch_mkfs -O casefold -C utf8 >> $seqres.full
	_scratch_mount $mntopt

	mkdir $dir
	$F2FS_IO_PROG setflags casefold $dir >> $seqres.full
	touch $redheart
	ino=`stat -c '%i' $redheart`
	_scratch_unmount

	# should tune nolinear_lookup feature before fault injection
	$F2FS_FSCK_PROG --nolinear-lookup=$nolinear_lookup $SCRATCH_DEV >> $seqres.full

	# check whether linear_lookup is changed as expected
	if [ $nolinear_lookup == "1" ]; then
		$F2FS_FSCK_PROG $SCRATCH_DEV | grep -q "linear_lookup \[disable\]" ||	\
					_fail "linear_lookup is not disabled"
	else
		$F2FS_FSCK_PROG $SCRATCH_DEV | grep -q "linear_lookup \[enable\]" ||	\
					_fail "linear_lookup is not enabled"
	fi

	$F2FS_INJECT_PROG --dent --mb d_hash --nid $ino --val 0x9a2ea068 $SCRATCH_DEV >> $seqres.full

	_scratch_mount $mntopt
	if [ $nolinear_lookup == "1" ]; then
		[ -f $redheart ] && _fail "red heart file should not exist"
	else
		[ -f $redheart ] || _fail "red heart file should exist"
	fi
	_scratch_unmount
}

check_lookup 1
check_lookup 0

echo "Silence is golden"

status=0
exit