#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2016 SUSE Linux Products GmbH. All Rights Reserved.
#
# FSQA Test No. 119
#
# Test log tree replay when qgroups are enabled and orphan roots (deleted
# snapshots) exist.
#
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()
{
	_cleanup_flakey
	cd /
	rm -f $tmp.*
}

# get standard environment, filters and checks
. ./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

_run_btrfs_util_prog quota enable $SCRATCH_MNT

# Create 2 directories with one file in one of them.
# We use these just to trigger a transaction commit later, moving the file from
# directory a to directory b and doing an fsync against directory a.
mkdir $SCRATCH_MNT/a
mkdir $SCRATCH_MNT/b
touch $SCRATCH_MNT/a/f
sync

# Create our test file with 2 4K extents.
$XFS_IO_PROG -f -s -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foobar | _filter_xfs_io

# Create a snapshot and delete it. This doesn't really delete the snapshot
# immediately, just makes it inaccessible and invisible to user space, the
# snapshot is deleted later by a dedicated kernel thread (cleaner kthread)
# which is woke up at the next transaction commit.
# A root orphan item is inserted into the tree of tree roots, so that if a
# power failure happens before the dedicated kernel thread does the snapshot
# deletion, the next time the filesystem is mounted it resumes the snapshot
# deletion.
_run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap
_run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap

# Now overwrite half of the extents we wrote before. Because we made a snapshpot
# before, which isn't really deleted yet (since no transaction commit happened
# after we did the snapshot delete request), the non overwritten extents get
# referenced twice, once by the default subvolume and once by the snapshot.
$XFS_IO_PROG -c "pwrite -S 0xbb 4K 8K" $SCRATCH_MNT/foobar | _filter_xfs_io

# Now move file f from directory a to directory b and fsync directory a.
# The fsync on the directory a triggers a transaction commit (because a file
# was moved from it to another directory) and the file fsync leaves a log tree
# with file extent items to replay.
mv $SCRATCH_MNT/a/f $SCRATCH_MNT/a/b
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar

echo "File digest before power failure:"
md5sum $SCRATCH_MNT/foobar | _filter_scratch

# Now simulate a power failure and mount the filesystem to replay the log tree.
# After the log tree was replayed, we used to hit a BUG_ON() when processing
# the root orphan item for the deleted snapshot. This is because when processing
# an orphan root the code expected to be the first code inserting the root into
# the fs_info->fs_root_radix radix tree, while in reallity it was the second
# caller attempting to do it - the first caller was the transaction commit that
# took place after replaying the log tree, when updating the qgroup counters.
_flakey_drop_and_remount

echo "File digest before after failure:"
# Must match what he got before the power failure.
md5sum $SCRATCH_MNT/foobar | _filter_scratch

_unmount_flakey

status=0
exit