-
Notifications
You must be signed in to change notification settings - Fork 19
/
addDevice.go
107 lines (99 loc) · 2.37 KB
/
addDevice.go
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
package unpacker
import (
"errors"
"fmt"
"os"
"path/filepath"
"time"
"github.com/Symantec/Dominator/lib/mbr"
)
var sysfsDirectory = "/sys/block"
func (u *Unpacker) addDevice(deviceId string) error {
u.updateUsageTime()
scannedDevices, err := scanDevices()
if err != nil {
return err
}
u.rwMutex.Lock()
defer u.rwMutex.Unlock()
defer u.updateUsageTimeWithLock()
for device := range u.scannedDevices {
delete(scannedDevices, device)
}
if len(scannedDevices) < 1 {
return errors.New("no new devices found")
}
if len(scannedDevices) > 1 {
return errors.New("too many new devices found")
}
var deviceName string
for d := range scannedDevices {
deviceName = d
}
device := deviceInfo{DeviceName: deviceName}
if err := updateDeviceSize(&device); err != nil {
return err
}
// Create a single partition. This is needed so that GRUB has a place to
// live (between the MBR and first/only partition).
devicePath := filepath.Join("/dev", deviceName)
u.logger.Printf("partitioning: %s\n", devicePath)
if err := mbr.WriteDefault(devicePath, mbr.TABLE_TYPE_MSDOS); err != nil {
return err
}
device.partitionTimestamp = time.Now()
u.pState.Devices[deviceId] = device
return u.writeStateWithLock()
}
func (u *Unpacker) prepareForAddDevice() error {
scannedDevices, err := scanDevices()
if err != nil {
return err
}
u.rwMutex.Lock()
defer u.rwMutex.Unlock()
u.scannedDevices = scannedDevices
return nil
}
func scanDevices() (map[string]struct{}, error) {
file, err := os.Open(sysfsDirectory)
if err != nil {
return nil, err
}
defer file.Close()
names, err := file.Readdirnames(-1)
if err != nil {
return nil, err
}
scannedDevices := make(map[string]struct{})
for _, name := range names {
scannedDevices[name] = struct{}{}
}
return scannedDevices, nil
}
func updateDeviceSize(device *deviceInfo) error {
deviceBlocks, err := readSysfsUint64(
filepath.Join(sysfsDirectory, device.DeviceName, "size"))
if err != nil {
return err
}
device.size = deviceBlocks * 512
return nil
}
func readSysfsUint64(filename string) (uint64, error) {
file, err := os.Open(filename)
if err != nil {
return 0, err
}
defer file.Close()
var value uint64
nScanned, err := fmt.Fscanf(file, "%d", &value)
if err != nil {
return 0, err
}
if nScanned < 1 {
return 0, errors.New(fmt.Sprintf("only read %d values from: %s",
nScanned, filename))
}
return value, nil
}