runtime: extend SharedFile to support mutiple storage devices

To enhance the construction and administration of `Katavirtualvolume` storages,
this commit expands the 'sharedFile' structure to manage both
rootfs storages(`containerStorages`) including `Katavirtualvolume` and other data volumes storages(`volumeStorages`).

NOTE: `volumeStorages` is intended for future extensions to support Kubernetes data volumes.
Currently, `KataVirtualVolume` is exclusively employed for container rootfs, hence only `containerStorages` is actively utilized.

Signed-off-by: ChengyuZhu6 <chengyu.zhu@intel.com>

src/runtime/virtcontainers/fs_share.go

@@ -21,7 +21,8 @@ var fsShareTracingTags = map[string]string{
 // SharedFile represents the outcome of a host filesystem sharing
 // operation.
 type SharedFile struct {
-	storage   *grpc.Storage
+	containerStorages []*grpc.Storage
+	volumeStorages    []*grpc.Storage
 	guestPath         string
 }
 

src/runtime/virtcontainers/fs_share_linux.go

@@ -438,7 +438,7 @@ func (f *FilesystemShare) shareRootFilesystemWithNydus(ctx context.Context, c *C
 	f.Logger().Infof("Nydus rootfs info: %#v\n", rootfs)
 
 	return &SharedFile{
-		storage:   rootfs,
+		containerStorages: []*grpc.Storage{rootfs},
 		guestPath:         rootfsGuestPath,
 	}, nil
 }
@@ -451,7 +451,7 @@ func (f *FilesystemShare) ShareRootFilesystem(ctx context.Context, c *Container)
 	// so there is no Rootfs.Target.
 	if f.sandbox.config.ServiceOffload && c.rootFs.Target == "" {
 		return &SharedFile{
-			storage:   nil,
+			containerStorages: nil,
 			guestPath:         rootfsGuestPath,
 		}, nil
 	}
@@ -463,13 +463,13 @@ func (f *FilesystemShare) ShareRootFilesystem(ctx context.Context, c *Container)
 	if HasOptionPrefix(c.rootFs.Options, annotations.FileSystemLayer) {
 		path := filepath.Join("/run/kata-containers", c.id, "rootfs")
 		return &SharedFile{
-			storage: &grpc.Storage{
+			containerStorages: []*grpc.Storage{{
 				MountPoint: path,
 				Source:     "none",
 				Fstype:     c.rootFs.Type,
 				Driver:     kataOverlayDevType,
 				Options:    c.rootFs.Options,
-			},
+			}},
 			guestPath: path,
 		}, nil
 	}
@@ -534,7 +534,7 @@ func (f *FilesystemShare) ShareRootFilesystem(ctx context.Context, c *Container)
 		}
 
 		return &SharedFile{
-			storage:   rootfsStorage,
+			containerStorages: []*grpc.Storage{rootfsStorage},
 			guestPath:         rootfsGuestPath,
 		}, nil
 	}
@@ -549,7 +549,7 @@ func (f *FilesystemShare) ShareRootFilesystem(ctx context.Context, c *Container)
 	}
 
 	return &SharedFile{
-		storage:   nil,
+		containerStorages: nil,
 		guestPath:         rootfsGuestPath,
 	}, nil
 }

src/runtime/virtcontainers/kata_agent.go

@@ -1258,12 +1258,17 @@ func (k *kataAgent) createContainer(ctx context.Context, sandbox *Sandbox, c *Co
 		return nil, err
 	}
 
-	if sharedRootfs.storage != nil {
+	if sharedRootfs.containerStorages != nil {
 		// Add rootfs to the list of container storage.
-		// We only need to do this for block based rootfs, as we
+		ctrStorages = append(ctrStorages, sharedRootfs.containerStorages...)
+	}
+
+	if sharedRootfs.volumeStorages != nil {
+		// Add volumeStorages to the list of container storage.
+		// We only need to do this for KataVirtualVolume based rootfs, as we
 		// want the agent to mount it into the right location
-		// (kataGuestSharedDir/ctrID/
-		ctrStorages = append(ctrStorages, sharedRootfs.storage)
+
+		ctrStorages = append(ctrStorages, sharedRootfs.volumeStorages...)
 	}
 
 	ociSpec := c.GetPatchedOCISpec()