#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2020 Synology.  All Rights Reserved.
#
# FS QA Test No. 154
#
# Test if btrfs rename handle dir item collision correctly
# Without patch fix, rename will fail with EOVERFLOW, and filesystem
# is forced readonly.
#
# This bug is going to be fixed by a patch for kernel titled
# "btrfs: correctly calculate item size used when item key collision happens"
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

here=`pwd`
tmp=/tmp/$$
status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

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

# get standard environment, filters and checks
. ./common/rc
. ./common/filter

# real QA test starts here

_supported_fs btrfs
_require_scratch
_require_command $PYTHON2_PROG python2

rm -f $seqres.full

# Currently in btrfs the node/leaf size can not be smaller than the page
# size (but it can be greater than the page size). So use the largest
# supported node/leaf size (64Kb) so that the test can run on any platform
# that Linux supports.
_scratch_mkfs "--nodesize 65536" >>$seqres.full 2>&1
_scratch_mount

#
# In the following for loop, we'll create a leaf fully occupied by
# only one dir item with many forged collision names in it.
#
# leaf 22544384 items 1 free space 0 generation 6 owner FS_TREE
# leaf 22544384 flags 0x1(WRITTEN) backref revision 1
# fs uuid 9064ba52-3d2c-4840-8e26-35db08fa17d7
# chunk uuid 9ba39317-3159-46c9-a75a-965ab1e94267
#    item 0 key (256 DIR_ITEM 3737737011) itemoff 25 itemsize 65410
#    ...
#

$PYTHON2_PROG $here/src/btrfs_crc32c_forged_name.py -d $SCRATCH_MNT -c 310
echo "Silence is golden"

# success, all done
status=0; exit