storage: Conserve LV state (from Incus) (#13986)

Reactivates an already-active volume after its size has been increased.
If a volume was active before being grown, it would be deactivated by
`SetVolumeQuota`; this retains the state of the LV after a size
adjustment.

Contains cherry-picks from lxc/incus#1021 and
lxc/incus#1136

incus#1021 is only partially applied as its other commit depends on
lxc/incus#512; I've made a note of this in the
tracking sheet.

lxd/storage/drivers/driver_lvm_volumes.go

@@ -449,16 +449,6 @@ func (d *lvm) SetVolumeQuota(vol Volume, size string, allowUnsafeResize bool, op
 
 	l := d.logger.AddContext(logger.Ctx{"dev": volDevPath, "size": fmt.Sprintf("%db", sizeBytes)})
 
-	// Activate volume if needed.
-	activated, err := d.activateVolume(vol)
-	if err != nil {
-		return err
-	}
-
-	if activated {
-		defer func() { _, _ = d.deactivateVolume(vol) }()
-	}
-
 	inUse := vol.MountInUse()
 
 	// Resize filesystem if needed.
@@ -474,13 +464,32 @@ func (d *lvm) SetVolumeQuota(vol Volume, size string, allowUnsafeResize bool, op
 				return ErrInUse // We don't allow online shrinking of filesytem volumes.
 			}
 
+			// Activate volume if needed.
+			activated, err := d.activateVolume(vol)
+			if err != nil {
+				return err
+			}
+
+			if !activated {
+				defer func() {
+					_, _ = d.activateVolume(vol)
+				}()
+			}
+
 			// Shrink filesystem first.
 			// Pass allowUnsafeResize to allow disabling of filesystem resize safety checks.
 			// We do this as a separate step rather than passing -r to lvresize in resizeLogicalVolume
 			// so that we can have more control over when we trigger unsafe filesystem resize mode,
 			// otherwise by passing -f to lvresize (required for other reasons) this would then pass
 			// -f onto resize2fs as well.
 			err = shrinkFileSystem(fsType, volDevPath, vol, sizeBytes, allowUnsafeResize)
+			if err != nil {
+				_, _ = d.deactivateVolume(vol)
+				return err
+			}
+
+			// Deactivate the volume for resizing.
+			_, err = d.deactivateVolume(vol)
 			if err != nil {
 				return err
 			}
@@ -499,6 +508,18 @@ func (d *lvm) SetVolumeQuota(vol Volume, size string, allowUnsafeResize bool, op
 				return err
 			}
 
+			// Activate the volume for resizing.
+			activated, err := d.activateVolume(vol)
+			if err != nil {
+				return err
+			}
+
+			if activated {
+				defer func() {
+					_, _ = d.deactivateVolume(vol)
+				}()
+			}
+
 			// Grow the filesystem to fill block device.
 			err = growFileSystem(fsType, volDevPath, vol)
 			if err != nil {
@@ -528,6 +549,18 @@ func (d *lvm) SetVolumeQuota(vol Volume, size string, allowUnsafeResize bool, op
 		// Move the VM GPT alt header to end of disk if needed (not needed in unsafe resize mode as it is
 		// expected the caller will do all necessary post resize actions themselves).
 		if vol.IsVMBlock() && !allowUnsafeResize {
+			// Activate the volume for resizing.
+			activated, err := d.activateVolume(vol)
+			if err != nil {
+				return err
+			}
+
+			if activated {
+				defer func() {
+					_, _ = d.deactivateVolume(vol)
+				}()
+			}
+
 			err = d.moveGPTAltHeader(volDevPath)
 			if err != nil {
 				return err