lxd: Add reverter to storagePoolVolumeUpdateUsers

storagePoolVolumeUpdateUsers is used in two places, one of which does not
currently use a reverter. If that update fails, the instances/profiles
could be left in an inconsistent state.

This pushes the reverter inside the function, so that it is safe to call
without needing a reverter.

My hunch is that this is also slightly less slow in case of failure.

Signed-off-by: Wesley Hershberger <[email protected]>

lxd/storage_volumes_utils.go

@@ -12,12 +12,17 @@ import (
 	storagePools "github.com/canonical/lxd/lxd/storage"
 	"github.com/canonical/lxd/shared"
 	"github.com/canonical/lxd/shared/api"
+	"github.com/canonical/lxd/shared/logger"
+	"github.com/canonical/lxd/shared/revert"
 	"github.com/canonical/lxd/shared/version"
 )
 
 var supportedVolumeTypes = []int{cluster.StoragePoolVolumeTypeContainer, cluster.StoragePoolVolumeTypeVM, cluster.StoragePoolVolumeTypeCustom, cluster.StoragePoolVolumeTypeImage}
 
 func storagePoolVolumeUpdateUsers(s *state.State, projectName string, oldPoolName string, oldVol *api.StorageVolume, newPoolName string, newVol *api.StorageVolume) error {
+	revert := revert.New()
+	defer revert.Fail()
+
 	// Update all instances that are using the volume with a local (non-expanded) device.
 	err := storagePools.VolumeUsedByInstanceDevices(s, oldPoolName, projectName, oldVol, false, func(dbInst db.InstanceArgs, project api.Project, usedByDevices []string) error {
 		inst, err := instance.Load(s, dbInst, project)
@@ -58,6 +63,17 @@ func storagePoolVolumeUpdateUsers(s *state.State, projectName string, oldPoolNam
 			return err
 		}
 
+		revert.Add(func() {
+			err := inst.Update(dbInst, false)
+			if err != nil {
+				logger.Error("Failed to revert instance update", logger.Ctx{
+					"project":  dbInst.Project,
+					"instance": dbInst.Name,
+					"error":    err,
+				})
+			}
+		})
+
 		return nil
 	})
 	if err != nil {
@@ -99,12 +115,29 @@ func storagePoolVolumeUpdateUsers(s *state.State, projectName string, oldPoolNam
 			return err
 		}
 
+		revert.Add(func() {
+			original := api.ProfilePut{
+				Config:      profile.Config,
+				Description: profile.Description,
+				Devices:     profile.Devices,
+			}
+			err := doProfileUpdate(s, p, profile.Name, profileID, &profile, original)
+			if err != nil {
+				logger.Error("Failed reverting profile update", logger.Ctx{
+					"project": p.Name,
+					"profile": profile.Name,
+					"error":   err,
+				})
+			}
+		})
+
 		return nil
 	})
 	if err != nil {
 		return err
 	}
 
+	revert.Success()
 	return nil
 }