Hack for go-winio vhd flushing vendorme

Signed-off-by: John Howard <jhoward@microsoft.com>

2 files changed, 102 insertions, 7 deletions

diff --git a/vendor/github.com/Microsoft/go-winio/vhd/vhd.go b/vendor/github.com/Microsoft/go-winio/vhd/vhd.go
index 8fa90e917c..b9f93ce168 100644
--- a/vendor/github.com/Microsoft/go-winio/vhd/vhd.go
+++ b/vendor/github.com/Microsoft/go-winio/vhd/vhd.go
@@ -2,12 +2,15 @@
 
 package vhd
 
-import "syscall"
+import (
+	"syscall"
+	"unsafe"
+)
 
 //go:generate go run mksyscall_windows.go -output zvhd.go vhd.go
 
 //sys createVirtualDisk(virtualStorageType *virtualStorageType, path string, virtualDiskAccessMask uint32, securityDescriptor *uintptr, flags uint32, providerSpecificFlags uint32, parameters *createVirtualDiskParameters, o *syscall.Overlapped, handle *syscall.Handle) (err error) [failretval != 0] = VirtDisk.CreateVirtualDisk
-//sys openVirtualDisk(virtualStorageType *virtualStorageType, path string, virtualDiskAccessMask uint32, flags uint32, parameters *uintptr, handle *syscall.Handle) (err error) [failretval != 0] = VirtDisk.OpenVirtualDisk
+//sys openVirtualDisk(virtualStorageType *virtualStorageType, path string, virtualDiskAccessMask uint32, flags uint32, parameters *openVirtualDiskParameters, handle *syscall.Handle) (err error) [failretval != 0] = VirtDisk.OpenVirtualDisk
 //sys detachVirtualDisk(handle syscall.Handle, flags uint32, providerSpecificFlags uint32) (err error) [failretval != 0] = VirtDisk.DetachVirtualDisk
 
 type virtualStorageType struct {
@@ -31,7 +34,24 @@ const createVirtualDiskFlagFullPhysicalAllocation uint32 = 1
 const createVirtualDiskFlagPreventWritesToSourceDisk uint32 = 2
 const createVirtualDiskFlagDoNotCopyMetadataFromParent uint32 = 4
 
-type version2 struct {
+const openVirtualDiskFlagNONE uint32 = 0
+const openVirtualDiskFlagNOPARENTS uint32 = 0x1
+const openVirtualDiskFlagBLANKFILE uint32 = 0x2
+const openVirtualDiskFlagBOOTDRIVE uint32 = 0x4
+const openVirtualDiskFlagCACHEDIO uint32 = 0x8
+const openVirtualDiskFlagCUSTOMDIFFCHAIN uint32 = 0x10
+const openVirtualDiskFlagPARENTCACHEDIO uint32 = 0x20
+const openVirtualDiskFlagVHDSETFILEONLY uint32 = 0x40
+const openVirtualDiskFlagIGNORERELATIVEPARENTLOCATOR uint32 = 0x80
+const openVirtualDiskFlagNOWRITEHARDENING uint32 = 0x100
+
+const vhdWriteCacheModeCacheMetadata uint16 = 0
+const vhdWriteCacheModeWriteInternalMetadata uint16 = 1
+const vhdWriteCacheModeWriteMetadata uint16 = 2
+const vhdWriteCacheModeCommitAll uint16 = 3
+const vhdWriteCacheModeDisableFlushing uint16 = 4
+
+type createVersion2 struct {
 	UniqueID                 [16]byte // GUID
 	MaximumSize              uint64
 	BlockSizeInBytes         uint32
@@ -46,7 +66,23 @@ type version2 struct {
 
 type createVirtualDiskParameters struct {
 	Version  uint32 // Must always be set to 2
-	Version2 version2
+	Version2 createVersion2
+}
+
+type openVersion2 struct {
+	GetInfoOnly    bool
+	ReadOnly       bool
+	ResiliencyGUID [16]byte // GUID
+}
+
+type openVirtualDiskParameters struct {
+	Version  uint32 // Must always be set to 2
+	Version2 openVersion2
+}
+
+type storageSetSurfaceCachePolicyRequest struct {
+	RequestLevel uint32
+	CacheMode    uint16
 }
 
 // CreateVhdx will create a simple vhdx file at the given path using default values.
@@ -55,7 +91,7 @@ func CreateVhdx(path string, maxSizeInGb, blockSizeInMb uint32) error {
 
 	parameters := createVirtualDiskParameters{
 		Version: 2,
-		Version2: version2{
+		Version2: createVersion2{
 			MaximumSize:      uint64(maxSizeInGb) * 1024 * 1024 * 1024,
 			BlockSizeInBytes: blockSizeInMb * 1024 * 1024,
 		},
@@ -106,3 +142,62 @@ func DetachVhd(path string) error {
 	}
 	return nil
 }
+
+// VhdWriteCacheModeDisableFlushing sets a VHDs surface cache policy to disable flushing.
+// It returns a handle which should be kept open during (for example) container start,
+// and restored using VhdWriteCacheModeCacheMetadata.
+func VhdWriteCacheModeDisableFlushing(path string) (syscall.Handle, error) {
+	handle, err := openVhd(path)
+	if err != nil {
+		return 0, err
+	}
+	if err := ioctlStorageSetSurfaceCachePolicy(handle, vhdWriteCacheModeDisableFlushing); err != nil {
+		syscall.CloseHandle(handle)
+		return 0, err
+	}
+	return handle, nil
+}
+
+// VhdWriteCacheModeCacheMetadata sets a VHDs surface cache policy to cache metadata
+func VhdWriteCacheModeCacheMetadata(handle syscall.Handle) error {
+	return ioctlStorageSetSurfaceCachePolicy(handle, vhdWriteCacheModeDisableFlushing)
+}
+
+// openVhd is a wrapper for getting a handle to a VHD.
+func openVhd(path string) (syscall.Handle, error) {
+	var (
+		defaultType virtualStorageType
+		handle      syscall.Handle
+	)
+	parameters := openVirtualDiskParameters{Version: 2}
+
+	if err := openVirtualDisk(
+		&defaultType,
+		path,
+		virtualDiskAccessNONE,
+		openVirtualDiskFlagCACHEDIO|openVirtualDiskFlagIGNORERELATIVEPARENTLOCATOR,
+		&parameters,
+		&handle); err != nil {
+		return 0, err
+	}
+
+	return handle, nil
+}
+
+func ioctlStorageSetSurfaceCachePolicy(handle syscall.Handle, cacheMode uint16) error {
+	request := storageSetSurfaceCachePolicyRequest{
+		RequestLevel: 1,
+		CacheMode:    cacheMode,
+	}
+	const storageSetSurfaceCachePolicy uint32 = 0x2d1a10
+	var bytesReturned uint32
+	return syscall.DeviceIoControl(
+		handle,
+		storageSetSurfaceCachePolicy,
+		(*byte)(unsafe.Pointer(&request)),
+		uint32(unsafe.Sizeof(request)),
+		nil,
+		0,
+		&bytesReturned,
+		nil)
+}
diff --git a/vendor/github.com/Microsoft/go-winio/vhd/zvhd.go b/vendor/github.com/Microsoft/go-winio/vhd/zvhd.go
index 73f52596ed..00599ea497 100644
--- a/vendor/github.com/Microsoft/go-winio/vhd/zvhd.go
+++ b/vendor/github.com/Microsoft/go-winio/vhd/zvhd.go
@@ -65,7 +65,7 @@ func _createVirtualDisk(virtualStorageType *virtualStorageType, path *uint16, vi
 	return
 }
 
-func openVirtualDisk(virtualStorageType *virtualStorageType, path string, virtualDiskAccessMask uint32, flags uint32, parameters *uintptr, handle *syscall.Handle) (err error) {
+func openVirtualDisk(virtualStorageType *virtualStorageType, path string, virtualDiskAccessMask uint32, flags uint32, parameters *openVirtualDiskParameters, handle *syscall.Handle) (err error) {
 	var _p0 *uint16
 	_p0, err = syscall.UTF16PtrFromString(path)
 	if err != nil {
@@ -74,7 +74,7 @@ func openVirtualDisk(virtualStorageType *virtualStorageType, path string, virtua
 	return _openVirtualDisk(virtualStorageType, _p0, virtualDiskAccessMask, flags, parameters, handle)
 }
 
-func _openVirtualDisk(virtualStorageType *virtualStorageType, path *uint16, virtualDiskAccessMask uint32, flags uint32, parameters *uintptr, handle *syscall.Handle) (err error) {
+func _openVirtualDisk(virtualStorageType *virtualStorageType, path *uint16, virtualDiskAccessMask uint32, flags uint32, parameters *openVirtualDiskParameters, handle *syscall.Handle) (err error) {
 	r1, _, e1 := syscall.Syscall6(procOpenVirtualDisk.Addr(), 6, uintptr(unsafe.Pointer(virtualStorageType)), uintptr(unsafe.Pointer(path)), uintptr(virtualDiskAccessMask), uintptr(flags), uintptr(unsafe.Pointer(parameters)), uintptr(unsafe.Pointer(handle)))
 	if r1 != 0 {
 		if e1 != 0 {