ceph-csi/pkg/cephfs/fsjournal.go
Madhu Rajanna 128f3fc2cf check subvolume present in backend
If a CreateVolume call is interrupted,
post creating the required CSI journal entries,
but prior to creating the backing CephFS subvolume,
then a subsequent CreateVolume call will return
a valid response with a VolumeID that has
it's backing image missing. This PR adds a check
for backend image, if image notfound it deletes the
reserved keys in omap.

fixes #839

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
2020-02-25 11:46:04 +00:00

158 lines
4.9 KiB
Go

/*
Copyright 2019 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 cephfs
import (
"context"
"github.com/ceph/ceph-csi/pkg/util"
"k8s.io/klog"
)
// volumeIdentifier structure contains an association between the CSI VolumeID to its subvolume
// name on the backing CephFS instance
type volumeIdentifier struct {
FsSubvolName string
VolumeID string
}
/*
checkVolExists checks to determine if passed in RequestName in volOptions exists on the backend.
**NOTE:** These functions manipulate the rados omaps that hold information regarding
volume names as requested by the CSI drivers. Hence, these need to be invoked only when the
respective CSI driver generated volume name based locks are held, as otherwise racy
access to these omaps may end up leaving them in an inconsistent state.
These functions also cleanup omap reservations that are stale. I.e when omap entries exist and
backing subvolumes are missing, or one of the omaps exist and the next is missing. This is
because, the order of omap creation and deletion are inverse of each other, and protected by the
request name lock, and hence any stale omaps are leftovers from incomplete transactions and are
hence safe to garbage collect.
*/
func checkVolExists(ctx context.Context, volOptions *volumeOptions, secret map[string]string) (*volumeIdentifier, error) {
var (
vi util.CSIIdentifier
vid volumeIdentifier
)
cr, err := util.NewAdminCredentials(secret)
if err != nil {
return nil, err
}
defer cr.DeleteCredentials()
imageUUID, err := volJournal.CheckReservation(ctx, volOptions.Monitors, cr,
volOptions.MetadataPool, volOptions.RequestName, volOptions.NamePrefix, "", "")
if err != nil {
return nil, err
}
if imageUUID == "" {
return nil, nil
}
// now that we now that the reservation exists, let's get the volume name from
// the omap
_, vid.FsSubvolName, _, _, err = volJournal.GetObjectUUIDData(ctx, volOptions.Monitors, cr,
volOptions.MetadataPool, imageUUID, false)
if err != nil {
return nil, err
}
_, err = getVolumeRootPathCeph(ctx, volOptions, cr, volumeID(vid.FsSubvolName))
if err != nil {
if _, ok := err.(ErrVolumeNotFound); ok {
err = volJournal.UndoReservation(ctx, volOptions.Monitors, cr, volOptions.MetadataPool, vid.FsSubvolName, volOptions.RequestName)
return nil, err
}
return nil, err
}
// TODO: size checks
// found a volume already available, process and return it!
vi = util.CSIIdentifier{
LocationID: volOptions.FscID,
EncodingVersion: volIDVersion,
ClusterID: volOptions.ClusterID,
ObjectUUID: imageUUID,
}
vid.VolumeID, err = vi.ComposeCSIID()
if err != nil {
return nil, err
}
klog.V(4).Infof(util.Log(ctx, "Found existing volume (%s) with subvolume name (%s) for request (%s)"),
vid.VolumeID, vid.FsSubvolName, volOptions.RequestName)
return &vid, nil
}
// undoVolReservation is a helper routine to undo a name reservation for a CSI VolumeName
func undoVolReservation(ctx context.Context, volOptions *volumeOptions, vid volumeIdentifier, secret map[string]string) error {
cr, err := util.NewAdminCredentials(secret)
if err != nil {
return err
}
defer cr.DeleteCredentials()
err = volJournal.UndoReservation(ctx, volOptions.Monitors, cr, volOptions.MetadataPool,
vid.FsSubvolName, volOptions.RequestName)
return err
}
// reserveVol is a helper routine to request a UUID reservation for the CSI VolumeName and,
// to generate the volume identifier for the reserved UUID
func reserveVol(ctx context.Context, volOptions *volumeOptions, secret map[string]string) (*volumeIdentifier, error) {
var (
vi util.CSIIdentifier
vid volumeIdentifier
imageUUID string
err error
)
cr, err := util.NewAdminCredentials(secret)
if err != nil {
return nil, err
}
defer cr.DeleteCredentials()
imageUUID, vid.FsSubvolName, err = volJournal.ReserveName(ctx, volOptions.Monitors, cr,
volOptions.MetadataPool, volOptions.RequestName, volOptions.NamePrefix, "", "")
if err != nil {
return nil, err
}
// generate the volume ID to return to the CO system
vi = util.CSIIdentifier{
LocationID: volOptions.FscID,
EncodingVersion: volIDVersion,
ClusterID: volOptions.ClusterID,
ObjectUUID: imageUUID,
}
vid.VolumeID, err = vi.ComposeCSIID()
if err != nil {
return nil, err
}
klog.V(4).Infof(util.Log(ctx, "Generated Volume ID (%s) and subvolume name (%s) for request name (%s)"),
vid.VolumeID, vid.FsSubvolName, volOptions.RequestName)
return &vid, nil
}