Storage: Use zero for unbound volumes' total size on the API

doc/rest-api.yaml

@@ -2516,13 +2516,13 @@ definitions:
     InstanceStateDisk:
         properties:
             total:
-                description: Total size in bytes. Uses -1 to convey that the instance has access to the entire pool's storage.
+                description: Total size in bytes. Uses 0 to convey that the instance has access to the entire pool's storage.
                 example: 502239232
                 format: int64
                 type: integer
                 x-go-name: Total
             usage:
-                description: Disk usage in bytes. Uses -1 to indicate that the storage driver for the instance's pool does not support retrieving the disk usage.
+                description: Disk usage in bytes. Uses 0 to indicate that the storage driver for the pool does not support retrieving disk usage.
                 example: 502239232
                 format: int64
                 type: integer
@@ -6703,13 +6703,13 @@ definitions:
         description: StorageVolumeStateUsage represents the disk usage of a volume
         properties:
             total:
-                description: Storage volume size in bytes
+                description: Storage volume size in bytes. Uses 0 to convey that the volume has access to the entire pool's storage.
                 example: 5189222192
                 format: int64
                 type: integer
                 x-go-name: Total
             used:
-                description: Used space in bytes
+                description: Used space in bytes. Uses 0 to indicate that the storage driver for the pool does not support retrieving volume usage.
                 example: 1693552640
                 format: uint64
                 type: integer

lxc/storage_volume.go

@@ -1484,7 +1484,10 @@ func (c *cmdStorageVolumeInfo) run(cmd *cobra.Command, args []string) error {
 	}
 
 	if volState != nil && volState.Usage != nil {
-		fmt.Printf(i18n.G("Usage: %s")+"\n", units.GetByteSizeStringIEC(int64(volState.Usage.Used), 2))
+		if volState.Usage.Used > 0 {
+			fmt.Printf(i18n.G("Usage: %s")+"\n", units.GetByteSizeStringIEC(int64(volState.Usage.Used), 2))
+		}
+
 		if volState.Usage.Total > 0 {
 			fmt.Printf(i18n.G("Total: %s")+"\n", units.GetByteSizeStringIEC(int64(volState.Usage.Total), 2))
 		}

lxd/storage/backend_lxd.go

@@ -3264,13 +3264,15 @@ func (b *lxdBackend) GetInstanceUsage(inst instance.Instance) (*VolumeUsage, err
 
 	// Get the usage
 	// If storage driver does not support getting the volume usage, proceed getting the total.
-	size, err := b.driver.GetVolumeUsage(vol)
+	usedBytes, err := b.driver.GetVolumeUsage(vol)
 	if err != nil && !errors.Is(err, drivers.ErrNotSupported) {
 		return nil, err
 	}
 
-	// If driver does not support getting volume usage, this value would be -1.
-	val.Used = size
+	// If driver does not support getting volume usage, this value should be 0.
+	if usedBytes > 0 {
+		val.Used = usedBytes
+	}
 
 	// Get the total size.
 	_, rootDiskConf, err := instancetype.GetRootDiskDevice(inst.ExpandedDevices().CloneNative())
@@ -3290,14 +3292,6 @@ func (b *lxdBackend) GetInstanceUsage(inst instance.Instance) (*VolumeUsage, err
 		}
 	}
 
-	// If the instance volume is neither block based/typed nor bound by the device's size config key,
-	// this means it is only bound by the pool limits and has access to the entire pool storage.
-	// So instead of showing the entire pool size for each instance disk, we return -1 to signify the root disk
-	// is unbounded below the pool level.
-	if val.Total == 0 {
-		val.Total = -1
-	}
-
 	return &val, nil
 }
 
@@ -6256,12 +6250,15 @@ func (b *lxdBackend) GetCustomVolumeUsage(projectName, volName string) (*VolumeU
 	vol := b.GetVolume(drivers.VolumeTypeCustom, drivers.ContentType(volume.ContentType), volStorageName, volume.Config)
 
 	// Get the usage.
-	size, err := b.driver.GetVolumeUsage(vol)
-	if err != nil {
+	usedBytes, err := b.driver.GetVolumeUsage(vol)
+	if err != nil && !errors.Is(err, drivers.ErrNotSupported) {
 		return nil, err
 	}
 
-	val.Used = size
+	// If retrieving usage is unsupported, Used should be 0.
+	if usedBytes > 0 {
+		val.Used = usedBytes
+	}
 
 	// Get the total size.
 	sizeStr, ok := vol.Config()["size"]

shared/api/instance_state.go

@@ -64,11 +64,11 @@ type InstanceState struct {
 //
 // API extension: instances.
 type InstanceStateDisk struct {
-	// Disk usage in bytes. Uses -1 to indicate that the storage driver for the instance's pool does not support retrieving the disk usage.
+	// Disk usage in bytes. Uses 0 to indicate that the storage driver for the pool does not support retrieving disk usage.
 	// Example: 502239232
 	Usage int64 `json:"usage" yaml:"usage"`
 
-	// Total size in bytes. Uses -1 to convey that the instance has access to the entire pool's storage.
+	// Total size in bytes. Uses 0 to convey that the instance has access to the entire pool's storage.
 	// Example: 502239232
 	//
 	// API extension: instances_state_total

shared/api/storage_pool_volume_state.go

@@ -16,11 +16,11 @@ type StorageVolumeState struct {
 //
 // API extension: storage_volume_state.
 type StorageVolumeStateUsage struct {
-	// Used space in bytes
+	// Used space in bytes. Uses 0 to indicate that the storage driver for the pool does not support retrieving volume usage.
 	// Example: 1693552640
-	Used uint64 `json:"used,omitempty" yaml:"used,omitempty"`
+	Used uint64 `json:"used" yaml:"used"`
 
-	// Storage volume size in bytes
+	// Storage volume size in bytes. Uses 0 to convey that the volume has access to the entire pool's storage.
 	// Example: 5189222192
 	//
 	// API extension: storage_volume_state_total

test/suites/storage.sh

@@ -929,12 +929,19 @@ EOF
 
     # Launch container.
     lxc launch -s "${pool_name}" testimage c1
+    lxc storage volume create "${pool_name}" fsvol
 
     # Disable quotas. The usage should be 0.
     # shellcheck disable=SC2031
     btrfs quota disable "${LXD_DIR}/storage-pools/${pool_name}"
-    # Usage -1 indicates the driver does not support getting instance usage.
-    [ "$(lxc query /1.0/instances/c1/state | jq '.disk.root.usage')" = "-1" ]
+    # Usage 0 indicates the driver does not support getting volume usage.
+    [ "$(lxc query /1.0/instances/c1/state | jq '.disk.root.usage')" = "0" ]
+    [ "$(lxc query "/1.0/storage-pools/${pool_name}/volumes/custom/fsvol/state" | jq '.usage.used')" = "0" ]
+    # Total 0 indicates the volume is unbound.
+    [ "$(lxc query /1.0/instances/c1/state | jq '.disk.root.total')" = "0" ]
+    [ "$(lxc query "/1.0/storage-pools/${pool_name}/volumes/custom/fsvol/state" | jq '.usage.total')" = "0" ]
+
+    lxc storage volume delete "${pool_name}" fsvol
 
     # Enable quotas. The usage should then be > 0.
     # shellcheck disable=SC2031