Support for storage space data disks

This commit adds support in hcsshim to mount a virtual disk backed by storage spaces as a
data disk into a container. In container config the `host_path` in the mount entry
should use the format `space://{storage_space_pool_guid}{storage_space_disk_guid}` to
specify a storage space virtual disk.

Signed-off-by: Amit Barve <ambarve@microsoft.com>

internal/hcsoci/hcsdoc_wcow.go

@@ -37,9 +37,7 @@ func createMountsConfig(ctx context.Context, coi *createOptionsInternal) (*mount
 	// TODO: Mapped pipes to add in v2 schema.
 	var config mountsConfig
 	for _, mount := range coi.Spec.Mounts {
-		if mount.Type != "" {
-			return nil, fmt.Errorf("invalid container spec - Mount.Type '%s' must not be set", mount.Type)
-		}
+
 		if uvm.IsPipe(mount.Source) {
 			src, dst := uvm.GetContainerPipeMapping(coi.HostingSystem, mount)
 			config.mpsv1 = append(config.mpsv1, schema1.MappedPipe{HostPath: src, ContainerPipeName: dst})
@@ -63,18 +61,26 @@ func createMountsConfig(ctx context.Context, coi *createOptionsInternal) (*mount
 					return nil, fmt.Errorf("failed to eval symlinks for mount source %q: %s", mount.Source, err)
 				}
 				mdv2.HostPath = src
+			} else if mount.Type == "virtual-disk" || mount.Type == "physical-disk" || mount.Type == "ExtensibleVirtualDisk" {
+
+				mountPath := mount.Source
+				var err error
+				if mount.Type == "extensible-virtual-disk" {
+					_, mountPath, err = uvm.ValidateExtensibleVirtualDiskMount(mount.Source)
+					if err != nil {
+						return nil, err
+					}
+				}
+				uvmPath, err := coi.HostingSystem.GetScsiUvmPath(ctx, mountPath)
+				if err != nil {
+					return nil, err
+				}
+				mdv2.HostPath = uvmPath
 			} else {
+				// vsmb mount
 				uvmPath, err := coi.HostingSystem.GetVSMBUvmPath(ctx, mount.Source, readOnly)
 				if err != nil {
-					if err == uvm.ErrNotAttached {
-						// It could also be a scsi mount.
-						uvmPath, err = coi.HostingSystem.GetScsiUvmPath(ctx, mount.Source)
-						if err != nil {
-							return nil, err
-						}
-					} else {
-						return nil, err
-					}
+					return nil, err
 				}
 				mdv2.HostPath = uvmPath
 			}

internal/hcsoci/resources_wcow.go

@@ -111,14 +111,15 @@ func setupMounts(ctx context.Context, coi *createOptionsInternal, r *resources.R
 	// Validate each of the mounts. If this is a V2 Xenon, we have to add them as
 	// VSMB shares to the utility VM. For V1 Xenon and Argons, there's nothing for
 	// us to do as it's done by HCS.
-	for i, mount := range coi.Spec.Mounts {
+	for _, mount := range coi.Spec.Mounts {
 		if mount.Destination == "" || mount.Source == "" {
 			return fmt.Errorf("invalid OCI spec - a mount must have both source and a destination: %+v", mount)
 		}
 		switch mount.Type {
 		case "":
 		case "physical-disk":
 		case "virtual-disk":
+		case "ExtensibleVirtualDisk":
 		default:
 			return fmt.Errorf("invalid OCI spec - Type '%s' not supported", mount.Type)
 		}
@@ -139,15 +140,20 @@ func setupMounts(ctx context.Context, coi *createOptionsInternal, r *resources.R
 				if err != nil {
 					return errors.Wrapf(err, "adding SCSI physical disk mount %+v", mount)
 				}
-				coi.Spec.Mounts[i].Type = ""
 				r.Add(scsiMount)
 			} else if mount.Type == "virtual-disk" {
 				l.Debug("hcsshim::allocateWindowsResources Hot-adding SCSI virtual disk for OCI mount")
 				scsiMount, err := coi.HostingSystem.AddSCSI(ctx, mount.Source, uvmPath, readOnly, uvm.VMAccessTypeIndividual)
 				if err != nil {
 					return errors.Wrapf(err, "adding SCSI virtual disk mount %+v", mount)
 				}
-				coi.Spec.Mounts[i].Type = ""
+				r.Add(scsiMount)
+			} else if mount.Type == "extensible-virtual-disk" {
+				l.Debug("hcsshim::allocateWindowsResource Hot-adding ExtensibleVirtualDisk")
+				scsiMount, err := coi.HostingSystem.AddSCSIExtensibleVirtualDisk(ctx, mount.Source, uvmPath, readOnly)
+				if err != nil {
+					return errors.Wrapf(err, "adding SCSI EVD mount failed %+v", mount)
+				}
 				r.Add(scsiMount)
 			} else {
 				if uvm.IsPipe(mount.Source) {

internal/schema2/attachment.go

@@ -27,4 +27,10 @@ type Attachment struct {
 	CaptureIoAttributionContext bool `json:"CaptureIoAttributionContext,omitempty"`
 
 	ReadOnly bool `json:"ReadOnly,omitempty"`
+
+	SupportCompressedVolumes bool `json:"SupportCompressedVolumes,omitempty"`
+
+	AlwaysAllowSparseFiles bool `json:"AlwaysAllowSparseFiles,omitempty"`
+
+	ExtensibleVirtualDiskType string `json:"ExtensibleVirtualDiskType,omitempty"`
 }

internal/uvm/create.go

@@ -7,7 +7,9 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"
 
+	"github.com/Microsoft/go-winio/pkg/guid"
 	"github.com/Microsoft/hcsshim/internal/cow"
 	"github.com/Microsoft/hcsshim/internal/hcs"
 	"github.com/Microsoft/hcsshim/internal/log"
@@ -391,3 +393,42 @@ func (uvm *UtilityVM) CloseGCSConnection() (err error) {
 	}
 	return
 }
+
+// validateStorageSpaceEVDPath verifies the host path provided for the mount
+// type "ExtensibleVirtualDisk" and ExtensibleVirtualDiskType "space"
+// The correct path is in the "space://{pool_guid}{disk_guid}" format.
+func validateStorageSpaceEVDPath(path string) error {
+	if !strings.HasPrefix(path, `space://{`) ||
+		!strings.HasSuffix(path, "}") {
+		return fmt.Errorf("storage space evd path must follow 'space://{pool_guid}{disk_guid}' format")
+	}
+	pool_guid_start := len(`space://{`)
+	pool_guid_end := pool_guid_start + 36 // length of GUID string
+	disk_guid_start := pool_guid_end + 2  // skips '}{'
+	disk_guid_end := disk_guid_start + 36
+	pool_guid := path[pool_guid_start:pool_guid_end]
+	disk_guid := path[disk_guid_start:disk_guid_end]
+	if _, err := guid.FromString(pool_guid); err != nil {
+		return fmt.Errorf("pool guid is not valid: %w", err)
+	}
+	if _, err := guid.FromString(disk_guid); err != nil {
+		return fmt.Errorf("disk guid is not valid: %w", err)
+	}
+	return nil
+}
+
+// ValidateExtensibleVirtulaDiskMount verifies that the `hostPath` provided is a valid extensible virtual
+// disk path. If it is a valid path then returns the `ExtensibleVirtualDiskType` of this mount and the
+// path that should be provided in the mount request to the uvm.
+func ValidateExtensibleVirtualDiskMount(hostPath string) (evdType, mountPath string, err error) {
+	if strings.HasPrefix(hostPath, `space://`) {
+		if err = validateStorageSpaceEVDPath(hostPath); err != nil {
+			return
+		}
+		evdType = "space"
+		mountPath = strings.TrimPrefix(hostPath, `space://`)
+	} else {
+		err = fmt.Errorf("unsupported Extensible virtual disk: %s", hostPath)
+	}
+	return
+}

internal/uvm/scsi.go

@@ -77,10 +77,14 @@ type SCSIMount struct {
 	refCount uint32
 	// specifies if this is a readonly layer
 	readOnly bool
-	// "VirtualDisk" or "PassThru" disk attachment type.
+	// "VirtualDisk" or "PassThru" or "ExtensibleVirtualDisk" disk attachment type.
 	attachmentType string
 	// serialization ID
 	serialVersionID uint32
+	// If attachmentType is "ExtensibleVirtualDisk" then extensibleVirtualDiskType should
+	// specify the type of it (for e.g "space" for storage spaces). Otherwise this should be
+	// empty.
+	extensibleVirtualDiskType string
 }
 
 // RefCount returns the current refcount for the SCSI mount.
@@ -90,13 +94,14 @@ func (sm *SCSIMount) RefCount() uint32 {
 
 func (sm *SCSIMount) logFormat() logrus.Fields {
 	return logrus.Fields{
-		"HostPath":        sm.HostPath,
-		"UVMPath":         sm.UVMPath,
-		"isLayer":         sm.isLayer,
-		"refCount":        sm.refCount,
-		"Controller":      sm.Controller,
-		"LUN":             sm.LUN,
-		"SerialVersionID": sm.serialVersionID,
+		"HostPath":                  sm.HostPath,
+		"UVMPath":                   sm.UVMPath,
+		"isLayer":                   sm.isLayer,
+		"refCount":                  sm.refCount,
+		"Controller":                sm.Controller,
+		"LUN":                       sm.LUN,
+		"SerialVersionID":           sm.serialVersionID,
+		"ExtensibleVirtualDiskType": sm.extensibleVirtualDiskType,
 	}
 }
 
@@ -114,6 +119,21 @@ func newSCSIMount(uvm *UtilityVM, hostPath, uvmPath, attachmentType string, refC
 	}
 }
 
+func newEVDSCSIMount(uvm *UtilityVM, hostPath, uvmPath string, refCount uint32, controller int, lun int32, readOnly bool, evdType string) *SCSIMount {
+	return &SCSIMount{
+		vm:                        uvm,
+		HostPath:                  hostPath,
+		UVMPath:                   uvmPath,
+		refCount:                  refCount,
+		Controller:                controller,
+		LUN:                       int32(lun),
+		readOnly:                  readOnly,
+		attachmentType:            "ExtensibleVirtualDisk",
+		serialVersionID:           scsiCurrentSerialVersionID,
+		extensibleVirtualDiskType: evdType,
+	}
+}
+
 // allocateSCSISlot finds the next available slot on the
 // SCSI controllers associated with a utility VM to use.
 // Lock must be held when calling this function
@@ -223,7 +243,7 @@ func (uvm *UtilityVM) RemoveSCSI(ctx context.Context, hostPath string) error {
 //
 // `vmAccess` indicates what access to grant the vm for the hostpath
 func (uvm *UtilityVM) AddSCSI(ctx context.Context, hostPath string, uvmPath string, readOnly bool, vmAccess VMAccessType) (*SCSIMount, error) {
-	return uvm.addSCSIActual(ctx, hostPath, uvmPath, "VirtualDisk", readOnly, vmAccess)
+	return uvm.addSCSIActual(ctx, hostPath, uvmPath, "VirtualDisk", readOnly, vmAccess, "")
 }
 
 // AddSCSIPhysicalDisk attaches a physical disk from the host directly to the
@@ -235,24 +255,54 @@ func (uvm *UtilityVM) AddSCSI(ctx context.Context, hostPath string, uvmPath stri
 //
 // `readOnly` set to `true` if the physical disk should be attached read only.
 func (uvm *UtilityVM) AddSCSIPhysicalDisk(ctx context.Context, hostPath, uvmPath string, readOnly bool) (*SCSIMount, error) {
-	return uvm.addSCSIActual(ctx, hostPath, uvmPath, "PassThru", readOnly, VMAccessTypeIndividual)
+	return uvm.addSCSIActual(ctx, hostPath, uvmPath, "PassThru", readOnly, VMAccessTypeIndividual, "")
 }
 
-// addSCSIActual is the implementation behind the external functions AddSCSI and
-// AddSCSIPhysicalDisk.
+// AddSCSIExtensibleVirtualDisk adds an extensible virtual disk as a SCSI mount
+// to the utility VM at the next available location. All such disks which are not actual virtual disks
+// but provide the same SCSI interface are added to the UVM as Extensible Virtual disks.
+// As of now only the virtual disks backed by storage spaces are supported.
+//
+// `hostPath` is required. Depending on the type of the extensible virtual disk the format of `hostPath` can
+// be different.
+// In case of storage space disks the host path must be in the
+// `space://{storage_pool_unique_ID}{virtual_disk_unique_ID}` format.
+//
+// `uvmPath` must be provided in order to be able to use this disk in a container.
+//
+// `readOnly` set to `true` if the virtual disk should be attached read only.
+//
+// `vmAccess` indicates what access to grant the vm for the hostpath
+func (uvm *UtilityVM) AddSCSIExtensibleVirtualDisk(ctx context.Context, hostPath, uvmPath string, readOnly bool) (*SCSIMount, error) {
+	if uvmPath == "" {
+		return nil, fmt.Errorf("uvmPath can not be empty for extensible virtual disk")
+	}
+	// check that the EVD is one of the supported types
+	evdType, mountPath, err := ValidateExtensibleVirtualDiskMount(hostPath)
+	if err != nil {
+		return nil, err
+	}
+	return uvm.addSCSIActual(ctx, mountPath, uvmPath, "ExtensibleVirtualDisk", readOnly, VMAccessTypeIndividual, evdType)
+}
+
+// addSCSIActual is the implementation behind the external functions AddSCSI,
+// AddSCSIPhysicalDisk, AddSCSIExtensibleVirtualDisk.
 //
 // We are in control of everything ourselves. Hence we have ref- counting and
 // so-on tracking what SCSI locations are available or used.
 //
 // `attachmentType` is required and `must` be `VirtualDisk` for vhd/vhdx
-// attachments and `PassThru` for physical disk.
+// attachments, `PassThru` for physical disk and "ExtensibleVirtualDisk" for Extensible virtual disk.
 //
 // `readOnly` indicates the attachment should be added read only.
 //
 // `vmAccess` indicates what access to grant the vm for the hostpath
 //
+// `evdType` indicates the `ExtensibleVirtualDiskType` if `attachmentType` is "ExtensibleVirtualDisk".
+// it should be empty otherwise.
+//
 // Returns result from calling modify with the given scsi mount
-func (uvm *UtilityVM) addSCSIActual(ctx context.Context, hostPath, uvmPath, attachmentType string, readOnly bool, vmAccess VMAccessType) (sm *SCSIMount, err error) {
+func (uvm *UtilityVM) addSCSIActual(ctx context.Context, hostPath, uvmPath, attachmentType string, readOnly bool, vmAccess VMAccessType, evdType string) (sm *SCSIMount, err error) {
 	sm, existed, err := uvm.allocateSCSIMount(ctx, readOnly, hostPath, uvmPath, attachmentType, vmAccess)
 	if err != nil {
 		return nil, err
@@ -280,9 +330,10 @@ func (uvm *UtilityVM) addSCSIActual(ctx context.Context, hostPath, uvmPath, atta
 	SCSIModification := &hcsschema.ModifySettingRequest{
 		RequestType: requesttype.Add,
 		Settings: hcsschema.Attachment{
-			Path:     sm.HostPath,
-			Type_:    attachmentType,
-			ReadOnly: readOnly,
+			Path:                      sm.HostPath,
+			Type_:                     attachmentType,
+			ReadOnly:                  readOnly,
+			ExtensibleVirtualDiskType: evdType,
 		},
 		ResourcePath: fmt.Sprintf(scsiResourceFormat, strconv.Itoa(sm.Controller), sm.LUN),
 	}
@@ -320,10 +371,12 @@ func (uvm *UtilityVM) addSCSIActual(ctx context.Context, hostPath, uvmPath, atta
 // Returns the resulting *SCSIMount, a bool indicating if the scsi device was already present,
 // and error if any.
 func (uvm *UtilityVM) allocateSCSIMount(ctx context.Context, readOnly bool, hostPath, uvmPath, attachmentType string, vmAccess VMAccessType) (*SCSIMount, bool, error) {
-	// Ensure the utility VM has access
-	err := grantAccess(ctx, uvm.id, hostPath, vmAccess)
-	if err != nil {
-		return nil, false, errors.Wrapf(err, "failed to grant VM access for SCSI mount")
+	if attachmentType != "ExtensibleVirtualDisk" {
+		// Ensure the utility VM has access
+		err := grantAccess(ctx, uvm.id, hostPath, vmAccess)
+		if err != nil {
+			return nil, false, errors.Wrapf(err, "failed to grant VM access for SCSI mount")
+		}
 	}
 	// We must hold the lock throughout the lookup (findSCSIAttachment) until
 	// after the possible allocation (allocateSCSISlot) has been completed to ensure