tests/btrfs/243

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2021 SUSE Linux Products GmbH.  All Rights Reserved.
#
# FS QA Test 243
#
# Test that if we explicitly fsync a file that was previously renamed and its
# size was increased through a truncate operation, after a power failure the
# file has the size set by truncate operation. In between the truncation and
# the fsync, there was a rename of another file in the same directory and that
# file was also fsynced before we fsynced the file that was truncated.
#
. ./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 btrfs
_require_scratch
_require_dm_target flakey

rm -f $seqres.full

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

# Create our test files.
touch $SCRATCH_MNT/foo
$XFS_IO_PROG -f -c "pwrite -S 0xab 0 1M" $SCRATCH_MNT/bar | _filter_xfs_io

# Make them durably persisted.
sync

# Fsync bar, this will be a noop since the file has not yet been modified in
# the current transaction. The goal here is to clear BTRFS_INODE_NEEDS_FULL_SYNC
# from the inode's runtime flags.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar

# Now rename both files, without changing their parent directory.
mv $SCRATCH_MNT/bar $SCRATCH_MNT/bar2
mv $SCRATCH_MNT/foo $SCRATCH_MNT/foo2

# Increase the size of bar2 with a truncate operation.
$XFS_IO_PROG -c "truncate 2M" $SCRATCH_MNT/bar2

# Now fsync foo2, this results in logging its parent inode (the root directory),
# and logging the parent results in logging the inode of file bar2 (its inode
# item and the new name). The inode of file bar2 is logged with an i_size of 0
# bytes since it's logged in LOG_INODE_EXISTS mode, meaning we are only logging
# its names (and xattrs if it had any) and the i_size of the inode will not be
# changed when the log is replayed.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo2

# Now explicitly fsync bar2. This resulted in doing nothing, not logging the
# inode with the new i_size of 2M and the hole from file offset 1M to 2M.
# Because the inode did not have the flag BTRFS_INODE_NEEDS_FULL_SYNC set, when
# it was logged through the fsync of file foo2, its last_log_commit field was
# updated, resulting in this explicit of file bar2 not doing anything.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar2

echo "File bar2 content before power failure:"
od -A d -t x1 $SCRATCH_MNT/bar2

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

echo "File bar2 content after power failure:"
od -A d -t x1 $SCRATCH_MNT/bar2

# While here, also check that the rename of foo to foo2 was durably persisted,
# even if it's not the specific regression the test is checking for.
[ -f $SCRATCH_MNT/foo2 ] || echo "File name foo2 does not exists"
[ -f $SCRATCH_MNT/foo ] && echo "File name foo still exists"

_unmount_flakey

# success, all done
status=0
exit