diff --git a/lxd/storage/backend_mock.go b/lxd/storage/backend_mock.go
index 850d268f13ca..19129702dc03 100644
--- a/lxd/storage/backend_mock.go
+++ b/lxd/storage/backend_mock.go
@@ -27,42 +27,52 @@ type mockBackend struct {
 	driver drivers.Driver
 }
 
+// ID ...
 func (b *mockBackend) ID() int64 {
 	return 1 //  The tests expect the storage pool ID to be 1.
 }
 
+// Name ...
 func (b *mockBackend) Name() string {
 	return b.name
 }
 
+// Description ...
 func (b *mockBackend) Description() string {
 	return ""
 }
 
+// ValidateName ...
 func (b *mockBackend) ValidateName(value string) error {
 	return nil
 }
 
+// Validate ...
 func (b *mockBackend) Validate(config map[string]string) error {
 	return nil
 }
 
+// Status ...
 func (b *mockBackend) Status() string {
 	return api.NetworkStatusUnknown
 }
 
+// LocalStatus ...
 func (b *mockBackend) LocalStatus() string {
 	return api.NetworkStatusUnknown
 }
 
+// ToAPI ...
 func (b *mockBackend) ToAPI() api.StoragePool {
 	return api.StoragePool{}
 }
 
+// Driver ...
 func (b *mockBackend) Driver() drivers.Driver {
 	return b.driver
 }
 
+// MigrationTypes ...
 func (b *mockBackend) MigrationTypes(contentType drivers.ContentType, refresh bool, copySnapshots bool) []migration.Type {
 	return []migration.Type{
 		{
@@ -72,86 +82,107 @@ func (b *mockBackend) MigrationTypes(contentType drivers.ContentType, refresh bo
 	}
 }
 
+// GetResources ...
 func (b *mockBackend) GetResources() (*api.ResourcesStoragePool, error) {
 	return nil, nil
 }
 
+// IsUsed ...
 func (b *mockBackend) IsUsed() (bool, error) {
 	return false, nil
 }
 
+// Delete ...
 func (b *mockBackend) Delete(clientType request.ClientType, op *operations.Operation) error {
 	return nil
 }
 
+// Update ...
 func (b *mockBackend) Update(clientType request.ClientType, newDescription string, newConfig map[string]string, op *operations.Operation) error {
 	return nil
 }
 
+// Create ...
 func (b *mockBackend) Create(clientType request.ClientType, op *operations.Operation) error {
 	return nil
 }
 
+// Mount ...
 func (b *mockBackend) Mount() (bool, error) {
 	return true, nil
 }
 
+// Unmount ...
 func (b *mockBackend) Unmount() (bool, error) {
 	return true, nil
 }
 
+// ApplyPatch ...
 func (b *mockBackend) ApplyPatch(name string) error {
 	return nil
 }
 
+// GetVolume ...
 func (b *mockBackend) GetVolume(volType drivers.VolumeType, contentType drivers.ContentType, volName string, volConfig map[string]string) drivers.Volume {
 	return drivers.Volume{}
 }
 
+// CreateInstance ...
 func (b *mockBackend) CreateInstance(inst instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// CreateInstanceFromBackup ...
 func (b *mockBackend) CreateInstanceFromBackup(srcBackup backup.Info, srcData io.ReadSeeker, op *operations.Operation) (func(instance.Instance) error, revert.Hook, error) {
 	return nil, nil, nil
 }
 
+// CreateInstanceFromCopy ...
 func (b *mockBackend) CreateInstanceFromCopy(inst instance.Instance, src instance.Instance, snapshots bool, allowInconsistent bool, op *operations.Operation) error {
 	return nil
 }
 
+// CreateInstanceFromImage ...
 func (b *mockBackend) CreateInstanceFromImage(inst instance.Instance, fingerprint string, op *operations.Operation) error {
 	return nil
 }
 
+// CreateInstanceFromMigration ...
 func (b *mockBackend) CreateInstanceFromMigration(inst instance.Instance, conn io.ReadWriteCloser, args migration.VolumeTargetArgs, op *operations.Operation) error {
 	return nil
 }
 
+// CreateInstanceFromConversion ...
 func (b *mockBackend) CreateInstanceFromConversion(inst instance.Instance, conn io.ReadWriteCloser, args migration.VolumeTargetArgs, op *operations.Operation) error {
 	return nil
 }
 
+// RenameInstance ...
 func (b *mockBackend) RenameInstance(inst instance.Instance, newName string, op *operations.Operation) error {
 	return nil
 }
 
+// DeleteInstance ...
 func (b *mockBackend) DeleteInstance(inst instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// UpdateInstance ...
 func (b *mockBackend) UpdateInstance(inst instance.Instance, newDesc string, newConfig map[string]string, op *operations.Operation) error {
 	return nil
 }
 
+// GenerateCustomVolumeBackupConfig ...
 func (b *mockBackend) GenerateCustomVolumeBackupConfig(projectName string, volName string, snapshots bool, op *operations.Operation) (*backupConfig.Config, error) {
 	return nil, nil
 }
 
+// GenerateInstanceBackupConfig ...
 func (b *mockBackend) GenerateInstanceBackupConfig(inst instance.Instance, snapshots bool, op *operations.Operation) (*backupConfig.Config, error) {
 	return nil, nil
 }
 
+// UpdateInstanceBackupFile ...
 func (b *mockBackend) UpdateInstanceBackupFile(inst instance.Instance, snapshot bool, op *operations.Operation) error {
 	return nil
 }
@@ -161,202 +192,252 @@ func (b *mockBackend) CheckInstanceBackupFileSnapshots(backupConf *backupConfig.
 	return nil, nil
 }
 
+// ListUnknownVolumes ...
 func (b *mockBackend) ListUnknownVolumes(op *operations.Operation) (map[string][]*backupConfig.Config, error) {
 	return nil, nil
 }
 
+// ImportInstance ...
 func (b *mockBackend) ImportInstance(inst instance.Instance, poolVol *backupConfig.Config, op *operations.Operation) (revert.Hook, error) {
 	return nil, nil
 }
 
+// MigrateInstance ...
 func (b *mockBackend) MigrateInstance(inst instance.Instance, conn io.ReadWriteCloser, args *migration.VolumeSourceArgs, op *operations.Operation) error {
 	return nil
 }
 
+// CleanupInstancePaths ...
 func (b *mockBackend) CleanupInstancePaths(inst instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// RefreshCustomVolume ...
 func (b *mockBackend) RefreshCustomVolume(projectName string, srcProjectName string, volName string, desc string, config map[string]string, srcPoolName, srcVolName string, srcVolOnly bool, op *operations.Operation) error {
 	return nil
 }
 
+// RefreshInstance ...
 func (b *mockBackend) RefreshInstance(inst instance.Instance, src instance.Instance, srcSnapshots []instance.Instance, allowInconsistent bool, op *operations.Operation) error {
 	return nil
 }
 
+// BackupInstance ...
 func (b *mockBackend) BackupInstance(inst instance.Instance, tarWriter *instancewriter.InstanceTarWriter, optimized bool, snapshots bool, op *operations.Operation) error {
 	return nil
 }
 
+// GetInstanceUsage ...
 func (b *mockBackend) GetInstanceUsage(inst instance.Instance) (*VolumeUsage, error) {
 	return nil, nil
 }
 
+// SetInstanceQuota ...
 func (b *mockBackend) SetInstanceQuota(inst instance.Instance, size string, vmStateSize string, op *operations.Operation) error {
 	return nil
 }
 
+// MountInstance ...
 func (b *mockBackend) MountInstance(inst instance.Instance, op *operations.Operation) (*MountInfo, error) {
 	return &MountInfo{}, nil
 }
 
+// UnmountInstance ...
 func (b *mockBackend) UnmountInstance(inst instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// CreateInstanceSnapshot ...
 func (b *mockBackend) CreateInstanceSnapshot(i instance.Instance, src instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// RenameInstanceSnapshot ...
 func (b *mockBackend) RenameInstanceSnapshot(inst instance.Instance, newName string, op *operations.Operation) error {
 	return nil
 }
 
+// DeleteInstanceSnapshot ...
 func (b *mockBackend) DeleteInstanceSnapshot(inst instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// RestoreInstanceSnapshot ...
 func (b *mockBackend) RestoreInstanceSnapshot(inst instance.Instance, src instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// MountInstanceSnapshot ...
 func (b *mockBackend) MountInstanceSnapshot(inst instance.Instance, op *operations.Operation) (*MountInfo, error) {
 	return &MountInfo{}, nil
 }
 
+// UnmountInstanceSnapshot ...
 func (b *mockBackend) UnmountInstanceSnapshot(inst instance.Instance, op *operations.Operation) error {
 	return nil
 }
 
+// UpdateInstanceSnapshot ...
 func (b *mockBackend) UpdateInstanceSnapshot(inst instance.Instance, newDesc string, newConfig map[string]string, op *operations.Operation) error {
 	return nil
 }
 
+// EnsureImage ...
 func (b *mockBackend) EnsureImage(fingerprint string, op *operations.Operation) error {
 	return nil
 }
 
+// DeleteImage ...
 func (b *mockBackend) DeleteImage(fingerprint string, op *operations.Operation) error {
 	return nil
 }
 
+// UpdateImage ...
 func (b *mockBackend) UpdateImage(fingerprint, newDesc string, newConfig map[string]string, op *operations.Operation) error {
 	return nil
 }
 
+// CreateBucket ...
 func (b *mockBackend) CreateBucket(projectName string, bucket api.StorageBucketsPost, op *operations.Operation) error {
 	return nil
 }
 
+// UpdateBucket ...
 func (b *mockBackend) UpdateBucket(projectName string, bucketName string, bucket api.StorageBucketPut, op *operations.Operation) error {
 	return nil
 }
 
+// DeleteBucket ...
 func (b *mockBackend) DeleteBucket(projectName string, bucketName string, op *operations.Operation) error {
 	return nil
 }
 
+// ImportBucket ...
 func (b *mockBackend) ImportBucket(projectName string, poolVol *backupConfig.Config, op *operations.Operation) (revert.Hook, error) {
 	return nil, nil
 }
 
+// CreateBucketKey ...
 func (b *mockBackend) CreateBucketKey(projectName string, bucketName string, key api.StorageBucketKeysPost, op *operations.Operation) (*api.StorageBucketKey, error) {
 	return nil, nil
 }
 
+// UpdateBucketKey ...
 func (b *mockBackend) UpdateBucketKey(projectName string, bucketName string, keyName string, key api.StorageBucketKeyPut, op *operations.Operation) error {
 	return nil
 }
 
+// DeleteBucketKey ...
 func (b *mockBackend) DeleteBucketKey(projectName string, bucketName string, keyName string, op *operations.Operation) error {
 	return nil
 }
 
+// ActivateBucket ...
 func (b *mockBackend) ActivateBucket(projectName string, bucketName string, op *operations.Operation) (*miniod.Process, error) {
 	return nil, nil
 }
 
+// GetBucketURL ...
 func (b *mockBackend) GetBucketURL(bucketName string) *url.URL {
 	return nil
 }
 
+// CreateCustomVolume ...
 func (b *mockBackend) CreateCustomVolume(projectName string, volName string, desc string, config map[string]string, contentType drivers.ContentType, op *operations.Operation) error {
 	return nil
 }
 
+// CreateCustomVolumeFromCopy ...
 func (b *mockBackend) CreateCustomVolumeFromCopy(projectName string, srcProjectName string, volName string, desc string, config map[string]string, srcPoolName string, srcVolName string, srcVolOnly bool, op *operations.Operation) error {
 	return nil
 }
 
+// RenameCustomVolume ...
 func (b *mockBackend) RenameCustomVolume(projectName string, volName string, newName string, op *operations.Operation) error {
 	return nil
 }
 
+// UpdateCustomVolume ...
 func (b *mockBackend) UpdateCustomVolume(projectName string, volName string, newDesc string, newConfig map[string]string, op *operations.Operation) error {
 	return nil
 }
 
+// DeleteCustomVolume ...
 func (b *mockBackend) DeleteCustomVolume(projectName string, volName string, op *operations.Operation) error {
 	return nil
 }
 
+// MigrateCustomVolume ...
 func (b *mockBackend) MigrateCustomVolume(projectName string, conn io.ReadWriteCloser, args *migration.VolumeSourceArgs, op *operations.Operation) error {
 	return nil
 }
 
+// CreateCustomVolumeFromMigration ...
 func (b *mockBackend) CreateCustomVolumeFromMigration(projectName string, conn io.ReadWriteCloser, args migration.VolumeTargetArgs, op *operations.Operation) error {
 	return nil
 }
 
+// GetCustomVolumeDisk ...
 func (b *mockBackend) GetCustomVolumeDisk(projectName string, volName string) (string, error) {
 	return "", nil
 }
 
+// GetCustomVolumeUsage ...
 func (b *mockBackend) GetCustomVolumeUsage(projectName string, volName string) (*VolumeUsage, error) {
 	return nil, nil
 }
 
+// MountCustomVolume ...
 func (b *mockBackend) MountCustomVolume(projectName string, volName string, op *operations.Operation) (*MountInfo, error) {
 	return nil, nil
 }
 
+// UnmountCustomVolume ...
 func (b *mockBackend) UnmountCustomVolume(projectName string, volName string, op *operations.Operation) (bool, error) {
 	return true, nil
 }
 
+// ImportCustomVolume ...
 func (b *mockBackend) ImportCustomVolume(projectName string, poolVol *backupConfig.Config, op *operations.Operation) (revert.Hook, error) {
 	return nil, nil
 }
 
+// CreateCustomVolumeSnapshot ...
 func (b *mockBackend) CreateCustomVolumeSnapshot(projectName string, volName string, newSnapshotName string, expiryDate time.Time, op *operations.Operation) error {
 	return nil
 }
 
+// RenameCustomVolumeSnapshot ...
 func (b *mockBackend) RenameCustomVolumeSnapshot(projectName string, volName string, newName string, op *operations.Operation) error {
 	return nil
 }
 
+// DeleteCustomVolumeSnapshot ...
 func (b *mockBackend) DeleteCustomVolumeSnapshot(projectName string, volName string, op *operations.Operation) error {
 	return nil
 }
 
+// UpdateCustomVolumeSnapshot ...
 func (b *mockBackend) UpdateCustomVolumeSnapshot(projectName string, volName string, newDesc string, newConfig map[string]string, expiryDate time.Time, op *operations.Operation) error {
 	return nil
 }
 
+// RestoreCustomVolume ...
 func (b *mockBackend) RestoreCustomVolume(projectName string, volName string, snapshotName string, op *operations.Operation) error {
 	return nil
 }
 
+// BackupCustomVolume ...
 func (b *mockBackend) BackupCustomVolume(projectName string, volName string, tarWriter *instancewriter.InstanceTarWriter, optimized bool, snapshots bool, op *operations.Operation) error {
 	return nil
 }
 
+// CreateCustomVolumeFromBackup ...
 func (b *mockBackend) CreateCustomVolumeFromBackup(srcBackup backup.Info, srcData io.ReadSeeker, op *operations.Operation) error {
 	return nil
 }
 
+// CreateCustomVolumeFromISO ...
 func (b *mockBackend) CreateCustomVolumeFromISO(projectName string, volName string, srcData io.ReadSeeker, size int64, op *operations.Operation) error {
 	return nil
 }