[PATCH] btrfs: Add test that checks rmdir(2) can delete a subvolume

[Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>]

Add btrfs test that checks "rmdir" or "rm -r" command can delete a
subvolume like an ordinary drectory.

This behavior has been restricted long time but becomes allowed by
following patch in the kernel:
  btrfs: Allow rmdir(2) to delete an empty subvolume

Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
---
 tests/btrfs/159     | 140 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/159.out |   2 +
 tests/btrfs/group   |   1 +
 3 files changed, 143 insertions(+)
 create mode 100755 tests/btrfs/159
 create mode 100644 tests/btrfs/159.out

diff --git a/tests/btrfs/159 b/tests/btrfs/159
new file mode 100755
index 00000000..2d830502
--- /dev/null
+++ b/tests/btrfs/159
@@ -0,0 +1,140 @@
+#! /bin/bash
+# FS QA Test btrfs/159
+#
+# QA test that checks rmdir(2) works for subvolumes like ordinary directories.
+#
+# This behavior has been restricted long time but becomes allowed by following
+# patch in the kernel:
+#   btrfs: Allow rmdir(2) to delete an empty subvolume
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2018 Fujitsu. All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+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.*
+}
+
+_create_subvol()
+{
+	$BTRFS_UTIL_PROG subvolume create $1 2>&1 | \
+		_filter_scratch >> $seqres.full
+}
+
+_create_snapshot()
+{
+	$BTRFS_UTIL_PROG subvolume snapshot $@ 2>&1 | \
+		_filter_scratch >> $seqres.full
+}
+
+_rmdir_subvol()
+{
+	rmdir $1 2>&1 | _filter_scratch
+	return ${PIPESTATUS[0]}
+}
+
+_rm_r_subvol() {
+	rm -r $1 2>&1 | _filter_scratch
+	return ${PIPESTATUS[0]}
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/btrfs
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+
+_scratch_mkfs > /dev/null 2>&1 || _fail "mkfs failed"
+_scratch_mount
+
+# Check that an empty subvolume can be deleted by rmdir
+_create_subvol $SCRATCH_MNT/sub1
+_rmdir_subvol $SCRATCH_MNT/sub1
+
+# Check that non-empty subvolume cannot be deleted by rmdir
+_create_subvol $SCRATCH_MNT/sub2
+touch $SCRATCH_MNT/sub2/file
+_rmdir_subvol $SCRATCH_MNT/sub2 >> $seqres.full && \
+	_fail "rmdir should fail for non-empty subvolume"
+rm $SCRATCH_MNT/sub2/file
+_rmdir_subvol $SCRATCH_MNT/sub2
+
+# Check that read-only empty subvolume can be deleted by rmdir
+_create_subvol $SCRATCH_MNT/sub3
+_create_snapshot -r $SCRATCH_MNT/sub3 $SCRATCH_MNT/snap
+$BTRFS_UTIL_PROG property set $SCRATCH_MNT/sub3 ro true 2>&1 | \
+	_filter_scratch >> $seqres.full
+_rmdir_subvol $SCRATCH_MNT/sub3
+_rmdir_subvol $SCRATCH_MNT/snap
+
+# Check that the default subvolume cannot be deleted by rmdir
+_create_subvol $SCRATCH_MNT/sub4
+subvolid=$(_btrfs_get_subvolid $SCRATCH_MNT sub4)
+$BTRFS_UTIL_PROG subvolume set-default $subvolid $SCRATCH_MNT 2>&1 | \
+	_filter_scratch >> $seqres.full
+_rmdir_subvol $SCRATCH_MNT/sub4 >> $seqres.full && \
+	_fail "rmdir should fail for the default subvolume"
+
+# Check that subvolume stub (created by snapshot) can be deleted by rmdir
+# (Note: this has been always allowed)
+_create_subvol $SCRATCH_MNT/sub5
+_create_subvol $SCRATCH_MNT/sub5/sub6
+_create_snapshot $SCRATCH_MNT/sub5 $SCRATCH_MNT/snap2
+rmdir $SCRATCH_MNT/snap2/sub6
+
+# Check that rm -r works for both non-snapshot subvolume and snapshot
+_create_subvol $SCRATCH_MNT/sub7
+mkdir $SCRATCH_MNT/sub7/dir
+_create_subvol $SCRATCH_MNT/sub7/dir/sub8
+touch $SCRATCH_MNT/sub7/dir/sub8/file
+
+_create_snapshot $SCRATCH_MNT/sub7 $SCRATCH_MNT/snap3
+_create_snapshot -r $SCRATCH_MNT/sub7 $SCRATCH_MNT/snap4
+
+_rm_r_subvol $SCRATCH_MNT/sub7
+_rm_r_subvol $SCRATCH_MNT/snap3
+_rm_r_subvol $SCRATCH_MNT/snap4 >> $seqres.full && \
+	_fail "rm -r should fail for non-empty readonly subvolume"
+
+$BTRFS_UTIL_PROG property set $SCRATCH_MNT/snap4 ro false 2>&1 | \
+	_filter_scratch >> $seqres.full
+_rm_r_subvol $SCRATCH_MNT/snap4
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/btrfs/159.out b/tests/btrfs/159.out
new file mode 100644
index 00000000..e569e60c
--- /dev/null
+++ b/tests/btrfs/159.out
@@ -0,0 +1,2 @@
+QA output created by 159
+Silence is golden
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 8007e07e..6a288285 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -161,3 +161,4 @@
 156 auto quick trim
 157 auto quick raid
 158 auto quick raid scrub
+159 auto quick subvol
-- 
2.14.3