Simplify config subvolume naming by using static "instance" prefix

cmd/incusd/patches.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 	"time"
 
+	internalInstance "github.com/lxc/incus/v6/internal/instance"
 	"github.com/lxc/incus/v6/internal/server/backup"
 	"github.com/lxc/incus/v6/internal/server/certificate"
 	"github.com/lxc/incus/v6/internal/server/cluster"
@@ -95,6 +96,7 @@ var patches = []patch{
 	{name: "network_ovn_directional_port_groups", stage: patchPostDaemonStorage, run: patchGenericNetwork(patchNetworkOVNPortGroups)},
 	{name: "pool_fix_default_permissions", stage: patchPostDaemonStorage, run: patchDefaultStoragePermissions},
 	{name: "auth_openfga_volume_files", stage: patchPostNetworks, run: patchGenericAuthorization},
+	{name: "btrfs_config_volume_subvolume_names", stage: patchPostNetworks, run: patchBtrfsSubvolumeNames},
 }
 
 type patchRun func(name string, d *Daemon) error
@@ -1650,4 +1652,105 @@ func patchDefaultStoragePermissions(_ string, d *Daemon) error {
 	return nil
 }
 
+// patchBtrfsSubvolumeNames updates Btrfs subvolume names for instance config volumes,
+// replacing the pattern '<instance-name>-' with 'instance-'.
+func patchBtrfsSubvolumeNames(_ string, d *Daemon) error {
+	s := d.State()
+
+	// Get the list of local instances.
+	instances, err := instance.LoadNodeAll(s, instancetype.Any)
+	if err != nil {
+		return fmt.Errorf("Failed loading local instances: %w", err)
+	}
+
+	for _, inst := range instances {
+		volType, err := storagePools.InstanceTypeToVolumeType(inst.Type())
+		if err != nil {
+			return err
+		}
+
+		// Get the volume name on storage.
+		volStorageName := project.Instance(inst.Project().Name, inst.Name())
+		contentType := storagePools.InstanceContentType(inst)
+
+		_, currentPool, _ := internalInstance.GetRootDiskDevice(inst.ExpandedDevices().CloneNative())
+
+		// Load storage pool.
+		p, err := storagePools.LoadByName(s, currentPool["pool"])
+		if err != nil {
+			logger.Error("Failed loading pool", logger.Ctx{"pool": currentPool["pool"], "err": err})
+			continue
+		}
+
+		// Check if driver is 'lvmcluster'.
+		if p.Driver().Info().Name != "lvmcluster" {
+			continue
+		}
+
+		// Load storage volume from database.
+		dbVol, err := storagePools.VolumeDBGet(p, inst.Project().Name, inst.Name(), volType)
+		if err != nil {
+			logger.Error("Failed loading volume", logger.Ctx{"vol": inst.Name(), "err": err})
+			continue
+		}
+
+		// Process only qcow2 instances.
+		if dbVol.Config["block.type"] != "qcow2" {
+			continue
+		}
+
+		vol := p.GetVolume(volType, contentType, volStorageName, dbVol.Config)
+
+		newName := storageDrivers.Qcow2ConfigVolumeBase
+		fsVol := vol.NewVMBlockFilesystemVolume()
+
+		// Increment the ref count for running instances,
+		// since it is equal zero at this stage and may cause an unintended volume deactivation.
+		if inst.IsRunning() {
+			fsVol.MountRefCountIncrement()
+		}
+
+		err = storageDrivers.Qcow2MountConfigTask(fsVol, nil, func(mountPath string) error {
+			_, volName := project.StorageVolumeParts(fsVol.Name())
+			entries, err := os.ReadDir(mountPath)
+			if err != nil {
+				return err
+			}
+
+			// Iterate through all entries (directories) and rename them.
+			for _, entry := range entries {
+				if !entry.IsDir() {
+					continue
+				}
+
+				oldName := entry.Name()
+
+				if oldName == volName || strings.HasPrefix(oldName, volName) {
+					newName := newName + strings.TrimPrefix(oldName, volName)
+
+					oldPath := filepath.Join(mountPath, oldName)
+					newPath := filepath.Join(mountPath, newName)
+
+					err := os.Rename(oldPath, newPath)
+					if err != nil {
+						return fmt.Errorf("Failed to rename %q to %q: %w", oldPath, newPath, err)
+					}
+				}
+			}
+
+			return nil
+		})
+		if err != nil {
+			logger.Error("Failed to rename btrfs subvolumes", logger.Ctx{"err": err})
+			continue
+		}
+
+		if inst.IsRunning() {
+			fsVol.MountRefCountDecrement()
+		}
+	}
+
+	return nil
+}
+
 // Patches end here

internal/server/storage/backend.go

@@ -8029,14 +8029,6 @@ func (b *backend) qcow2Rename(vol drivers.Volume, newVolName string, projectName
 		return err
 	}
 
-	if vol.IsVMBlock() {
-		fsVol := vol.NewVMBlockFilesystemVolume()
-		err := drivers.Qcow2RenameConfig(fsVol, newVolName, op)
-		if err != nil {
-			return err
-		}
-	}
-
 	return nil
 }
 

internal/server/storage/drivers/utils_qcow2.go

@@ -13,7 +13,6 @@ import (
 
 	"github.com/lxc/incus/v6/internal/linux"
 	"github.com/lxc/incus/v6/internal/server/operations"
-	"github.com/lxc/incus/v6/internal/server/project"
 	internalUtil "github.com/lxc/incus/v6/internal/util"
 	"github.com/lxc/incus/v6/shared/api"
 	"github.com/lxc/incus/v6/shared/subprocess"
@@ -25,6 +24,9 @@ const (
 	BlockVolumeTypeQcow2 = "qcow2"
 )
 
+// Qcow2ConfigVolumeBase represents the base component of a Btrfs subvolume name.
+const Qcow2ConfigVolumeBase = "instance"
+
 // ImageInfo contains information about a qcow2 image.
 type ImageInfo struct {
 	BackingFilename string `json:"backing-filename"`
@@ -192,8 +194,7 @@ func Qcow2MountConfigTask(vol Volume, op *operations.Operation, task func(mountP
 // Qcow2CreateConfig creates the btrfs config filesystem associated with the QCOW2 block volume.
 func Qcow2CreateConfig(vol Volume, op *operations.Operation) error {
 	err := Qcow2MountConfigTask(vol, op, func(mountPath string) error {
-		_, volName := project.StorageVolumeParts(vol.Name())
-		volPath := filepath.Join(mountPath, volName)
+		volPath := filepath.Join(mountPath, Qcow2ConfigVolumeBase)
 		// Create the volume itself.
 		_, err := subprocess.RunCommand("btrfs", "subvolume", "create", volPath)
 		if err != nil {
@@ -209,52 +210,12 @@ func Qcow2CreateConfig(vol Volume, op *operations.Operation) error {
 	return nil
 }
 
-// Qcow2RenameConfig renames the btrfs config filesystem associated with the QCOW2 block volume.
-func Qcow2RenameConfig(vol Volume, newName string, op *operations.Operation) error {
-	err := Qcow2MountConfigTask(vol, op, func(mountPath string) error {
-		_, volName := project.StorageVolumeParts(vol.Name())
-		entries, err := os.ReadDir(mountPath)
-		if err != nil {
-			return err
-		}
-
-		// Iterate through all entries (directories) and rename them.
-		for _, entry := range entries {
-			if !entry.IsDir() {
-				continue
-			}
-
-			oldName := entry.Name()
-
-			if oldName == volName || strings.HasPrefix(oldName, volName) {
-				newName := newName + strings.TrimPrefix(oldName, volName)
-
-				oldPath := filepath.Join(mountPath, oldName)
-				newPath := filepath.Join(mountPath, newName)
-
-				err := os.Rename(oldPath, newPath)
-				if err != nil {
-					return fmt.Errorf("Failed to rename %q to %q: %w", oldPath, newPath, err)
-				}
-			}
-		}
-
-		return nil
-	})
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
 // Qcow2CreateConfigSnapshot creates the btrfs snapshot of the config filesystem associated with the QCOW2 block volume.
 func Qcow2CreateConfigSnapshot(vol Volume, snapVol Volume, op *operations.Operation) error {
 	err := Qcow2MountConfigTask(vol, op, func(mountPath string) error {
-		fullParent, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
-		_, parent := project.StorageVolumeParts(fullParent)
-		dstPath := filepath.Join(mountPath, fmt.Sprintf("%s-%s", parent, snapName))
-		srcPath := filepath.Join(mountPath, parent)
+		_, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
+		dstPath := filepath.Join(mountPath, fmt.Sprintf("%s-%s", Qcow2ConfigVolumeBase, snapName))
+		srcPath := filepath.Join(mountPath, Qcow2ConfigVolumeBase)
 
 		_, err := subprocess.RunCommand("btrfs", "subvolume", "snapshot", srcPath, dstPath)
 		if err != nil {
@@ -273,17 +234,16 @@ func Qcow2CreateConfigSnapshot(vol Volume, snapVol Volume, op *operations.Operat
 // Qcow2RestoreConfigSnapshot restores the btrfs snapshot of the config filesystem associated with the QCOW2 block volume.
 func Qcow2RestoreConfigSnapshot(vol Volume, snapVol Volume, op *operations.Operation) error {
 	err := Qcow2MountConfigTask(vol, op, func(mountPath string) error {
-		fullParent, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
-		_, parent := project.StorageVolumeParts(fullParent)
-		snapPath := fmt.Sprintf("%s-%s", parent, snapName)
+		_, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
+		snapPath := fmt.Sprintf("%s-%s", Qcow2ConfigVolumeBase, snapName)
 
 		// Delete the subvolume itself.
-		_, err := subprocess.RunCommand("btrfs", "subvolume", "delete", filepath.Join(mountPath, parent))
+		_, err := subprocess.RunCommand("btrfs", "subvolume", "delete", filepath.Join(mountPath, Qcow2ConfigVolumeBase))
 		if err != nil {
 			return err
 		}
 
-		_, err = subprocess.RunCommand("btrfs", "subvolume", "snapshot", filepath.Join(mountPath, snapPath), filepath.Join(mountPath, parent))
+		_, err = subprocess.RunCommand("btrfs", "subvolume", "snapshot", filepath.Join(mountPath, snapPath), filepath.Join(mountPath, Qcow2ConfigVolumeBase))
 		if err != nil {
 			return err
 		}
@@ -300,10 +260,9 @@ func Qcow2RestoreConfigSnapshot(vol Volume, snapVol Volume, op *operations.Opera
 // Qcow2RenameConfigSnapshot renames the btrfs snapshot of the config filesystem associated with the QCOW2 block volume.
 func Qcow2RenameConfigSnapshot(vol Volume, snapVol Volume, newName string, op *operations.Operation) error {
 	err := Qcow2MountConfigTask(vol, op, func(mountPath string) error {
-		fullParent, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
-		_, parent := project.StorageVolumeParts(fullParent)
-		oldPath := filepath.Join(mountPath, fmt.Sprintf("%s-%s", parent, snapName))
-		newPath := filepath.Join(mountPath, fmt.Sprintf("%s-%s", parent, newName))
+		_, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
+		oldPath := filepath.Join(mountPath, fmt.Sprintf("%s-%s", Qcow2ConfigVolumeBase, snapName))
+		newPath := filepath.Join(mountPath, fmt.Sprintf("%s-%s", Qcow2ConfigVolumeBase, newName))
 
 		err := os.Rename(oldPath, newPath)
 		if err != nil {
@@ -322,9 +281,8 @@ func Qcow2RenameConfigSnapshot(vol Volume, snapVol Volume, newName string, op *o
 // Qcow2DeleteConfigSnapshot deletes the btrfs snapshot of the config filesystem associated with the QCOW2 block volume.
 func Qcow2DeleteConfigSnapshot(vol Volume, snapVol Volume, op *operations.Operation) error {
 	err := Qcow2MountConfigTask(vol, op, func(mountPath string) error {
-		fullParent, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
-		_, parent := project.StorageVolumeParts(fullParent)
-		path := filepath.Join(mountPath, fmt.Sprintf("%s-%s", parent, snapName))
+		_, snapName, _ := api.GetParentAndSnapshotName(snapVol.Name())
+		path := filepath.Join(mountPath, fmt.Sprintf("%s-%s", Qcow2ConfigVolumeBase, snapName))
 
 		// Delete the subvolume itself.
 		_, err := subprocess.RunCommand("btrfs", "subvolume", "delete", path)

internal/server/storage/drivers/volume.go

@@ -20,7 +20,6 @@ import (
 	internalInstance "github.com/lxc/incus/v6/internal/instance"
 	"github.com/lxc/incus/v6/internal/server/locking"
 	"github.com/lxc/incus/v6/internal/server/operations"
-	"github.com/lxc/incus/v6/internal/server/project"
 	"github.com/lxc/incus/v6/internal/server/refcount"
 	"github.com/lxc/incus/v6/internal/server/state"
 	internalUtil "github.com/lxc/incus/v6/internal/util"
@@ -610,11 +609,10 @@ func (v Volume) ConfigBlockFilesystem() string {
 // "block.mount_options" if defined in volume or pool's volume config, otherwise defaultFilesystemMountOptions.
 func (v Volume) ConfigBlockMountOptions() string {
 	if v.ExpandedConfig("block.type") == BlockVolumeTypeQcow2 && !v.mountFullFilesystem {
-		fullParent, snapName, isSnap := api.GetParentAndSnapshotName(v.name)
-		_, parent := project.StorageVolumeParts(fullParent)
-		subvol := parent
+		_, snapName, isSnap := api.GetParentAndSnapshotName(v.name)
+		subvol := Qcow2ConfigVolumeBase
 		if isSnap {
-			subvol = fmt.Sprintf("%s-%s", parent, snapName)
+			subvol = fmt.Sprintf("%s-%s", Qcow2ConfigVolumeBase, snapName)
 		}
 
 		return fmt.Sprintf("subvol=%s", subvol)