ceph-csi/internal/rbd/snapshot.go
Madhu Rajanna e3a63029a3 rbd: Implement snapshot and clone from snapshot
This Adds a support for create,delete snapshot
and creating a new rbd image from the snapshot.

* Create a snapshot

* Create a temporary snapshot from the parent volume
* Clone a new image from a temporary snapshot with options
  --rbd-default-clone-format 2 --image-feature layering,deep-flatten
* Delete temporary snapshot created
* Create a new snapshot from cloned image
* Check the image chain depth, if the Softlimit is reached Add a
  task Flatten the cloned image and return success. if the depth
  is reached hard limit Add a task Flatten the cloned image and
  return snapshot status ready as false

```bash
1) rbd snap create <RBD image for src k8s volume>@<random snap name>
2) rbd clone --rbd-default-clone-format 2 --image-feature
   layering,deep-flatten <RBD image for src k8s volume>@<random snap>
   <RBD image for temporary snap image>
3) rbd snap rm <RBD image for src k8s volume>@<random snap name>
4) rbd snap rm <RBD image for temporary snap image>@<random snap name>
5) check the depth, if the depth is greater than configured hard
   limit add a task to flatten the cloned image return snapshot status
   ready as false if the depth is greater than soft limit add a task
   to flatten the image and return success
```

* Create a clone from snapshot

* Clone a new image from the snapshot with user-provided options
* Check the depth(n) of the cloned image if n>=(hard limit)
  Add task to flatten the image and return ABORT (to avoid image leak)

```bash
1) rbd clone --rbd-default-clone-format 2 --image-feature
   <k8s dst vol config> <RBD image for temporary snap image>@<random snap name>
    <RBD image for k8s dst vol>
2) check the depth, if the depth is greater than configured hard limit
    add a task to flatten the cloned image return ABORT error if the depth is
    greater than soft limit add a task to flatten the image and return success
```

* Delete snapshot or pvc

* Move the temporary cloned image to the trash
* Add task to remove the image from the trash

```bash
1) rbd trash mv <cloned image>
2) ceph rbd task trash remove <cloned image>
```

With earlier implementation to delete the image, we used to add
a task to remove the image with new changes this cannot be done
as the image may contain snapshots or linking.so we will be
doing below steps to delete an image(this will be
applicable for both normal image and cloned image)

* Move the rbd image to the trash
* Add task to remove the image from the trash

```bash
1) rbd trash mv <image>
2) ceph rbd task trash remove <image>
```

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
2020-07-01 08:21:47 +00:00

102 lines
3.2 KiB
Go

/*
Copyright 2020 The Ceph-CSI Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package rbd
import (
"context"
"github.com/ceph/ceph-csi/internal/util"
"github.com/pkg/errors"
"k8s.io/klog"
)
func createRBDClone(ctx context.Context, parentVol, cloneRbdVol *rbdVolume, snap *rbdSnapshot, cr *util.Credentials) error {
// create snapshot
err := parentVol.createSnapshot(ctx, snap)
if err != nil {
klog.Errorf(util.Log(ctx, "failed to create snapshot %s: %v"), snap, err)
return err
}
// create clone image and delete snapshot
err = cloneRbdVol.cloneRbdImageFromSnapshot(ctx, snap)
if err != nil {
klog.Errorf(util.Log(ctx, "failed to clone rbd image %s from snapshot %s: %v"), cloneRbdVol.RbdImageName, snap.RbdSnapName, err)
err = errors.Errorf("failed to clone rbd image %s from snapshot %s: %v", cloneRbdVol.RbdImageName, snap.RbdSnapName, err)
}
errSnap := parentVol.deleteSnapshot(ctx, snap)
if errSnap != nil {
klog.Errorf(util.Log(ctx, "failed to delete snapshot: %v"), errSnap)
delErr := deleteImage(ctx, cloneRbdVol, cr)
if delErr != nil {
klog.Errorf(util.Log(ctx, "failed to delete rbd image: %s with error: %v"), cloneRbdVol, delErr)
}
return err
}
err = cloneRbdVol.getImageInfo()
if err != nil {
klog.Errorf(util.Log(ctx, "failed to get rbd image: %s details with error: %v"), cloneRbdVol, err)
delErr := deleteImage(ctx, cloneRbdVol, cr)
if delErr != nil {
klog.Errorf(util.Log(ctx, "failed to delete rbd image: %s with error: %v"), cloneRbdVol, delErr)
}
return err
}
return nil
}
func cleanUpSnapshot(ctx context.Context, parentVol *rbdVolume, rbdSnap *rbdSnapshot, rbdVol *rbdVolume, cr *util.Credentials) error {
err := parentVol.deleteSnapshot(ctx, rbdSnap)
if err != nil {
if _, ok := err.(ErrSnapNotFound); !ok {
klog.Errorf(util.Log(ctx, "failed to delete snapshot: %v"), err)
return err
}
}
err = deleteImage(ctx, rbdVol, cr)
if err != nil {
if _, ok := err.(ErrImageNotFound); !ok {
klog.Errorf(util.Log(ctx, "failed to delete rbd image: %s/%s with error: %v"), rbdVol.Pool, rbdVol.VolName, err)
return err
}
}
return nil
}
func generateVolFromSnap(rbdSnap *rbdSnapshot) *rbdVolume {
vol := new(rbdVolume)
vol.ClusterID = rbdSnap.ClusterID
vol.VolID = rbdSnap.SnapID
vol.Monitors = rbdSnap.Monitors
vol.Pool = rbdSnap.Pool
vol.JournalPool = rbdSnap.JournalPool
vol.RbdImageName = rbdSnap.RbdSnapName
return vol
}
func undoSnapshotCloning(ctx context.Context, parentVol *rbdVolume, rbdSnap *rbdSnapshot, cloneVol *rbdVolume, cr *util.Credentials) error {
err := cleanUpSnapshot(ctx, parentVol, rbdSnap, cloneVol, cr)
if err != nil {
klog.Errorf(util.Log(ctx, "failed to clean up %s or %s: %v"), cloneVol, rbdSnap, err)
return err
}
err = undoSnapReservation(ctx, rbdSnap, cr)
return err
}