tests/generic/690

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2022 SUSE Linux Products GmbH.  All Rights Reserved.
#
# FS QA Test 690
#
# Test that if we fsync a directory, create a symlink inside it, rename the
# symlink, fsync again the directory and then power fail, after the filesystem
# is mounted again, the symlink exists with the new name and it has the correct
# content.
#
# On btrfs this used to result in the symlink being empty (i_size 0), and it was
# fixed by kernel commit:
#
#    d0e64a981fd841 ("btrfs: always log symlinks in full mode")
#
. ./common/preamble
_begin_fstest auto quick log

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

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

# real QA test starts here

_supported_fs generic
_require_scratch
_require_symlinks
_require_dm_target flakey

rm -f $seqres.full

# f2fs doesn't support fs-op level transaction functionality, so it has no way
# to persist all metadata updates in one transaction. We have to use its mount
# option "fastboot" so that it triggers a metadata checkpoint to persist all
# metadata updates that happen before a fsync call. Without this, after the
# last fsync in the test, the symlink named "baz" will not exist.
if [ $FSTYP = "f2fs" ]; then
	export MOUNT_OPTIONS="-o fastboot $MOUNT_OPTIONS"
fi

_scratch_mkfs >>$seqres.full 2>&1
_require_metadata_journaling $SCRATCH_DEV
_init_flakey
_mount_flakey

# Create our test directory.
mkdir "$SCRATCH_MNT"/testdir

# Commit the current transaction and persist the directory.
sync

# Create a file in the test directory, so that the next fsync on the directory
# actually does something (it logs the directory).
echo -n > "$SCRATCH_MNT"/testdir/foo

# Fsync the directory.
$XFS_IO_PROG -c "fsync" "$SCRATCH_MNT"/testdir

# Now create a symlink inside the test directory.
ln -s "$SCRATCH_MNT"/testdir/foo "$SCRATCH_MNT"/testdir/bar

# Rename the symlink.
mv "$SCRATCH_MNT"/testdir/bar "$SCRATCH_MNT"/testdir/baz

# Fsync again the directory.
$XFS_IO_PROG -c "fsync" "$SCRATCH_MNT"/testdir

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

# The symlink should exist, with the name "baz" and its content must be
# "$SCRATCH_MNT/testdir/foo".
[ -L "$SCRATCH_MNT"/testdir/baz ] || echo "symlink 'baz' is missing"
symlink_content=$(readlink "$SCRATCH_MNT"/testdir/baz | _filter_scratch)
echo "symlink content: ${symlink_content}"

_unmount_flakey

# success, all done
status=0
exit