tests/generic/782

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2025 SUSE S.A.  All Rights Reserved.
#
# FS QA Test No. 782
#
# Test that if we add a new directory to the root directory, change a file in
# the root directory, fsync the file, add a hard link for the file inside the
# new directory and then fsync the root directory, after a power failure the
# root directory has the entry for the new directory.
#
. ./common/preamble
_begin_fstest auto quick log

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

. ./common/filter
. ./common/dmflakey

_require_scratch
_require_dm_target flakey

[ "$FSTYP" = "btrfs" ] && _fixed_by_kernel_commit bfe3d755ef7c \
	"btrfs: do not update last_log_commit when logging inode due to a new name"

_scratch_mkfs >>$seqres.full 2>&1 || _fail "mkfs failed"
_require_metadata_journaling $SCRATCH_DEV
_init_flakey
_mount_flakey

# Create our test file.
touch $SCRATCH_MNT/foo

# Make sure it's durably persisted.
_scratch_sync

# Create a test directory in the root dir.
mkdir $SCRATCH_MNT/dir

# Write some data to the file and fsync it.
$XFS_IO_PROG -c "pwrite -S 0xab 0 64K" \
	     -c "fsync" $SCRATCH_MNT/foo | _filter_xfs_io

# Add a hard link for our file inside the test directory.
# On btrfs this causes updating the file's inode and both parent
# directories in the log tree (in memory only).
ln $SCRATCH_MNT/foo $SCRATCH_MNT/dir/bar

# Fsync the root directory.
# We expect it to persist the entry for directory "dir".
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/

# Simulate a power failure and then mount again the filesystem to replay the
# journal/log.
_flakey_drop_and_remount

# The directory "dir" should be present as well as file "foo".
# Filter the 'lost+found' that only exists in some filesystems like ext4.
echo "Root content:"
ls -1 $SCRATCH_MNT | grep -v 'lost+found'

# Also check file "foo" has the expected data.
echo "File data:"
_hexdump $SCRATCH_MNT/foo

_unmount_flakey

_exit 0