cephfs admin: add subvolume snapshot create, remove, and list funcs

Add CreateSubVolumeSnapshot function.
Add RemoveSubVolumeSnapshot function.
Add ListSubVolumeSnapshots function.
Add tests for the above.

Signed-off-by: John Mulligan <jmulligan@redhat.com>

cephfs/admin/subvolume.go

@@ -211,3 +211,56 @@ func (fsa *FSAdmin) SubVolumeInfo(volume, group, name string) (*SubVolumeInfo, e
 	}
 	return parseSubVolumeInfo(fsa.marshalMgrCommand(m))
 }
+
+// CreateSubVolumeSnapshot creates a new snapshot from the source subvolume.
+//
+// Similar To:
+//  ceph fs subvolume snapshot create <volume> --group-name=<group> <source> <name>
+func (fsa *FSAdmin) CreateSubVolumeSnapshot(volume, group, source, name string) error {
+	m := map[string]string{
+		"prefix":    "fs subvolume snapshot create",
+		"vol_name":  volume,
+		"sub_name":  source,
+		"snap_name": name,
+		"format":    "json",
+	}
+	if group != NoGroup {
+		m["group_name"] = group
+	}
+	return checkEmptyResponseExpected(fsa.marshalMgrCommand(m))
+}
+
+// RemoveSubVolumeSnapshot removes the specified snapshot from the subvolume.
+//
+// Similar To:
+//  ceph fs subvolume snapshot rm <volume> --group-name=<group> <subvolume> <name>
+func (fsa *FSAdmin) RemoveSubVolumeSnapshot(volume, group, subvolume, name string) error {
+	m := map[string]string{
+		"prefix":    "fs subvolume snapshot rm",
+		"vol_name":  volume,
+		"sub_name":  subvolume,
+		"snap_name": name,
+		"format":    "json",
+	}
+	if group != NoGroup {
+		m["group_name"] = group
+	}
+	return checkEmptyResponseExpected(fsa.marshalMgrCommand(m))
+}
+
+// ListSubVolumeSnapshots returns a listing of snapshots for a given subvolume.
+//
+// Similar To:
+//  ceph fs subvolume snapshot ls <volume> --group-name=<group> <name>
+func (fsa *FSAdmin) ListSubVolumeSnapshots(volume, group, name string) ([]string, error) {
+	m := map[string]string{
+		"prefix":   "fs subvolume snapshot ls",
+		"vol_name": volume,
+		"sub_name": name,
+		"format":   "json",
+	}
+	if group != NoGroup {
+		m["group_name"] = group
+	}
+	return parseListNames(fsa.marshalMgrCommand(m))
+}

cephfs/admin/subvolume_test.go

@@ -347,3 +347,72 @@ func TestSubVolumeInfo(t *testing.T) {
 	assert.Equal(t, 040750, vinfo.Mode)
 	assert.GreaterOrEqual(t, 2020, vinfo.Ctime.Year())
 }
+
+func TestSubVolumeSnapshots(t *testing.T) {
+	fsa := getFSAdmin(t)
+	volume := "cephfs"
+	group := "20000leagues"
+	subname := "nautilus"
+	snapname1 := "ne1"
+	snapname2 := "mo2"
+
+	err := fsa.CreateSubVolumeGroup(volume, group, nil)
+	assert.NoError(t, err)
+	defer func() {
+		err := fsa.RemoveSubVolumeGroup(volume, group)
+		assert.NoError(t, err)
+	}()
+
+	svopts := &SubVolumeOptions{
+		Mode: 0750,
+		Size: 20 * gibiByte,
+	}
+	err = fsa.CreateSubVolume(volume, group, subname, svopts)
+	assert.NoError(t, err)
+	defer func() {
+		err := fsa.RemoveSubVolume(volume, group, subname)
+		assert.NoError(t, err)
+	}()
+
+	t.Run("createAndRemove", func(t *testing.T) {
+		err = fsa.CreateSubVolumeSnapshot(volume, group, subname, snapname1)
+		assert.NoError(t, err)
+		err := fsa.RemoveSubVolumeSnapshot(volume, group, subname, snapname1)
+		assert.NoError(t, err)
+	})
+
+	t.Run("listOne", func(t *testing.T) {
+		err = fsa.CreateSubVolumeSnapshot(volume, group, subname, snapname1)
+		assert.NoError(t, err)
+		defer func() {
+			err := fsa.RemoveSubVolumeSnapshot(volume, group, subname, snapname1)
+			assert.NoError(t, err)
+		}()
+
+		snaps, err := fsa.ListSubVolumeSnapshots(volume, group, subname)
+		assert.NoError(t, err)
+		assert.Len(t, snaps, 1)
+		assert.Contains(t, snaps, snapname1)
+	})
+
+	t.Run("listTwo", func(t *testing.T) {
+		err = fsa.CreateSubVolumeSnapshot(volume, group, subname, snapname1)
+		assert.NoError(t, err)
+		defer func() {
+			err := fsa.RemoveSubVolumeSnapshot(volume, group, subname, snapname1)
+			assert.NoError(t, err)
+		}()
+		err = fsa.CreateSubVolumeSnapshot(volume, group, subname, snapname2)
+		assert.NoError(t, err)
+		defer func() {
+			err := fsa.RemoveSubVolumeSnapshot(volume, group, subname, snapname2)
+			assert.NoError(t, err)
+		}()
+
+		snaps, err := fsa.ListSubVolumeSnapshots(volume, group, subname)
+		assert.NoError(t, err)
+		assert.Len(t, snaps, 2)
+		assert.Contains(t, snaps, snapname1)
+		assert.Contains(t, snaps, snapname2)
+	})
+}