rbd: add wrapper for rbd_snap_get_timestamp()

Added a wrapper for rbd_snap_get_timestamp() function.

Signed-off-by: Mudit Agarwal <muagarwa@redhat.com>

rbd/snapshot.go

@@ -7,6 +7,8 @@ import "C"
 
 import (
 	"unsafe"
+
+	ts "github.com/ceph/go-ceph/internal/timespec"
 )
 
 // Snapshot represents a snapshot on a particular rbd image.
@@ -160,3 +162,25 @@ func (snapshot *Snapshot) Set() error {
 
 	return getError(C.rbd_snap_set(snapshot.image.image, c_snapname))
 }
+
+// GetSnapTimestamp returns the timestamp of a snapshot for an image.
+// For a non-existing snap ID, GetSnapTimestamp() may trigger an assertion
+// and crash in the ceph library.
+// Check https://tracker.ceph.com/issues/47287 for details.
+//
+// Implements:
+//  int rbd_snap_get_timestamp(rbd_image_t image, uint64_t snap_id, struct timespec *timestamp)
+func (image *Image) GetSnapTimestamp(snapID uint64) (Timespec, error) {
+	if err := image.validate(imageIsOpen); err != nil {
+		return Timespec{}, err
+	}
+
+	var cts C.struct_timespec
+
+	ret := C.rbd_snap_get_timestamp(image.image, C.uint64_t(snapID), &cts)
+	if ret < 0 {
+		return Timespec{}, getError(ret)
+	}
+
+	return Timespec(ts.CStructToTimespec(ts.CTimespecPtr(&cts))), nil
+}

rbd/snapshot_test.go

@@ -105,3 +105,82 @@ func TestErrorSnapshotNoName(t *testing.T) {
 	conn.DeletePool(poolname)
 	conn.Shutdown()
 }
+
+func TestGetSnapTimestamp(t *testing.T) {
+	conn := radosConnect(t)
+	poolName := GetUUID()
+	err := conn.MakePool(poolName)
+	assert.NoError(t, err)
+	ioctx, err := conn.OpenIOContext(poolName)
+	assert.NoError(t, err)
+
+	defer func() {
+		ioctx.Destroy()
+		assert.NoError(t, conn.DeletePool(poolName))
+		conn.Shutdown()
+	}()
+
+	t.Run("ClosedImage", func(t *testing.T) {
+		imgName := "someImage"
+		img, err := Create(ioctx, imgName, testImageSize, testImageOrder, 1)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, img.Remove())
+		}()
+		var snapID uint64
+		snapID = 22
+		_, err = img.GetSnapTimestamp(snapID)
+		assert.Error(t, err)
+		assert.Equal(t, err, ErrImageNotOpen)
+	})
+
+	t.Run("invalidSnapID", func(t *testing.T) {
+		t.Skip("hits assert due to https://tracker.ceph.com/issues/47287")
+		imgName := "someImage"
+		img, err := Create(ioctx, imgName, testImageSize, testImageOrder, 1)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, img.Remove())
+		}()
+
+		img, err = OpenImage(ioctx, imgName, NoSnapshot)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, img.Close())
+		}()
+
+		var snapID uint64
+		snapID = 22
+		_, err = img.GetSnapTimestamp(snapID)
+		assert.Error(t, err)
+	})
+
+	t.Run("happyPath", func(t *testing.T) {
+		imgName := "someImage"
+		img, err := Create(ioctx, imgName, testImageSize, testImageOrder, 1)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, img.Remove())
+		}()
+
+		img, err = OpenImage(ioctx, imgName, NoSnapshot)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, img.Close())
+		}()
+
+		snapName := "mysnap"
+		snapshot, err := img.CreateSnapshot(snapName)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, snapshot.Remove())
+		}()
+
+		snapInfo, err := img.GetSnapshotNames()
+		assert.NoError(t, err)
+		assert.Equal(t, snapName, snapInfo[0].Name)
+		snapID := snapInfo[0].Id
+		_, err = img.GetSnapTimestamp(snapID)
+		assert.NoError(t, err)
+	})
+}