1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
// +build windows
package vhd
import "syscall"
//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 *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 {
DeviceID uint32
VendorID [16]byte
}
type (
createVirtualDiskFlag uint32
VirtualDiskAccessMask uint32
VirtualDiskFlag uint32
)
const (
// Flags for creating a VHD (not exported)
createVirtualDiskFlagNone createVirtualDiskFlag = 0
createVirtualDiskFlagFullPhysicalAllocation createVirtualDiskFlag = 1
createVirtualDiskFlagPreventWritesToSourceDisk createVirtualDiskFlag = 2
createVirtualDiskFlagDoNotCopyMetadataFromParent createVirtualDiskFlag = 4
// Access Mask for opening a VHD
VirtualDiskAccessNone VirtualDiskAccessMask = 0
VirtualDiskAccessAttachRO VirtualDiskAccessMask = 65536
VirtualDiskAccessAttachRW VirtualDiskAccessMask = 131072
VirtualDiskAccessDetach VirtualDiskAccessMask = 262144
VirtualDiskAccessGetInfo VirtualDiskAccessMask = 524288
VirtualDiskAccessCreate VirtualDiskAccessMask = 1048576
VirtualDiskAccessMetaOps VirtualDiskAccessMask = 2097152
VirtualDiskAccessRead VirtualDiskAccessMask = 851968
VirtualDiskAccessAll VirtualDiskAccessMask = 4128768
VirtualDiskAccessWritable VirtualDiskAccessMask = 3276800
// Flags for opening a VHD
OpenVirtualDiskFlagNone VirtualDiskFlag = 0
OpenVirtualDiskFlagNoParents VirtualDiskFlag = 0x1
OpenVirtualDiskFlagBlankFile VirtualDiskFlag = 0x2
OpenVirtualDiskFlagBootDrive VirtualDiskFlag = 0x4
OpenVirtualDiskFlagCachedIO VirtualDiskFlag = 0x8
OpenVirtualDiskFlagCustomDiffChain VirtualDiskFlag = 0x10
OpenVirtualDiskFlagParentCachedIO VirtualDiskFlag = 0x20
OpenVirtualDiskFlagVhdSetFileOnly VirtualDiskFlag = 0x40
OpenVirtualDiskFlagIgnoreRelativeParentLocator VirtualDiskFlag = 0x80
OpenVirtualDiskFlagNoWriteHardening VirtualDiskFlag = 0x100
)
type createVersion2 struct {
UniqueID [16]byte // GUID
MaximumSize uint64
BlockSizeInBytes uint32
SectorSizeInBytes uint32
ParentPath *uint16 // string
SourcePath *uint16 // string
OpenFlags uint32
ParentVirtualStorageType virtualStorageType
SourceVirtualStorageType virtualStorageType
ResiliencyGUID [16]byte // GUID
}
type createVirtualDiskParameters struct {
Version uint32 // Must always be set to 2
Version2 createVersion2
}
type openVersion2 struct {
GetInfoOnly int32 // bool but 4-byte aligned
ReadOnly int32 // bool but 4-byte aligned
ResiliencyGUID [16]byte // GUID
}
type openVirtualDiskParameters struct {
Version uint32 // Must always be set to 2
Version2 openVersion2
}
// CreateVhdx will create a simple vhdx file at the given path using default values.
func CreateVhdx(path string, maxSizeInGb, blockSizeInMb uint32) error {
var (
defaultType virtualStorageType
handle syscall.Handle
)
parameters := createVirtualDiskParameters{
Version: 2,
Version2: createVersion2{
MaximumSize: uint64(maxSizeInGb) * 1024 * 1024 * 1024,
BlockSizeInBytes: blockSizeInMb * 1024 * 1024,
},
}
if err := createVirtualDisk(
&defaultType,
path,
uint32(VirtualDiskAccessNone),
nil,
uint32(createVirtualDiskFlagNone),
0,
¶meters,
nil,
&handle); err != nil {
return err
}
if err := syscall.CloseHandle(handle); err != nil {
return err
}
return nil
}
// DetachVhd detaches a mounted container layer vhd found at `path`.
func DetachVhd(path string) error {
handle, err := OpenVirtualDisk(
path,
VirtualDiskAccessNone,
OpenVirtualDiskFlagCachedIO|OpenVirtualDiskFlagIgnoreRelativeParentLocator)
if err != nil {
return err
}
defer syscall.CloseHandle(handle)
return detachVirtualDisk(handle, 0, 0)
}
// OpenVirtualDisk obtains a handle to a VHD opened with supplied access mask and flags.
func OpenVirtualDisk(path string, accessMask VirtualDiskAccessMask, flag VirtualDiskFlag) (syscall.Handle, error) {
var (
defaultType virtualStorageType
handle syscall.Handle
)
parameters := openVirtualDiskParameters{Version: 2}
if err := openVirtualDisk(
&defaultType,
path,
uint32(accessMask),
uint32(flag),
¶meters,
&handle); err != nil {
return 0, err
}
return handle, nil
}
|
