tests/btrfs/202

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# FS QA Test 201
#
# Regression test for fix "btrfs: fix invalid removal of root ref"
#
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.*
}

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

rm -f $seqres.full

_supported_fs btrfs

_scratch_mkfs >> $seqres.full 2>&1
_scratch_mount

# Create a subvol b under a and then snapshot a into c.  This create's a stub
# entry in c for b because c doesn't have a reference for b.
#
# But when we rename b c/foo it creates a ref for b in c.  However if we go to
# remove c/b btrfs used to depend on not finding the root ref to handle the
# unlink properly, but we now have a ref for that root.  We also had a bug that
# would allow us to remove mis-matched refs if the keys matched, so we'd end up
# removing too many entries which would cause a transaction abort.

$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/a | _filter_scratch
$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/a/b | _filter_scratch
$BTRFS_UTIL_PROG subvolume snapshot $SCRATCH_MNT/a $SCRATCH_MNT/c \
	| _filter_scratch

# Need the dummy entry created so that we get the invalid removal when we rmdir
ls $SCRATCH_MNT/c/b

mkdir $SCRATCH_MNT/c/foo
mv $SCRATCH_MNT/a/b $SCRATCH_MNT/c/foo
rm -rf $SCRATCH_MNT/*
touch $SCRATCH_MNT/blah

status=0
exit