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
|
// this file almost totally copied from MSDN
#include <windows.h>
#include <stdio.h>
#include <winioctl.h>
#define LOCK_TIMEOUT 3000 // 10 Seconds
#define LOCK_RETRIES 20
static HANDLE OpenVolume(TCHAR cDriveLetter)
{
HANDLE hVolume;
UINT uDriveType;
wchar_t szVolumeName[8] = {0};
wchar_t szRootName[5] = {0};
DWORD dwAccessFlags;
wsprintf(szRootName, L"%c:\\", cDriveLetter);
uDriveType = GetDriveType(szRootName);
switch(uDriveType) {
case DRIVE_REMOVABLE:
dwAccessFlags = GENERIC_READ | GENERIC_WRITE;
break;
case DRIVE_CDROM:
dwAccessFlags = GENERIC_READ;
break;
default:
printf("Cannot eject. Drive type is incorrect.\n");
return INVALID_HANDLE_VALUE;
}
wsprintf(szVolumeName, L"\\\\.\\%c:", cDriveLetter);
hVolume = CreateFile( szVolumeName,
dwAccessFlags,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
0,
NULL );
if (hVolume == INVALID_HANDLE_VALUE)
printf("CreateFile error %d\n", GetLastError());
return hVolume;
}
static BOOL CloseVolume(HANDLE hVolume)
{
return CloseHandle(hVolume);
}
static BOOL LockVolume(HANDLE hVolume)
{
DWORD dwBytesReturned;
DWORD dwSleepAmount;
int nTryCount;
dwSleepAmount = LOCK_TIMEOUT / LOCK_RETRIES;
// Do this in a loop until a timeout period has expired
for (nTryCount = 0; nTryCount < LOCK_RETRIES; nTryCount++) {
if (DeviceIoControl(hVolume,
FSCTL_LOCK_VOLUME,
NULL, 0,
NULL, 0,
&dwBytesReturned,
NULL))
return TRUE;
Sleep(dwSleepAmount);
}
return FALSE;
}
static BOOL DismountVolume(HANDLE hVolume)
{
DWORD dwBytesReturned;
return DeviceIoControl( hVolume,
FSCTL_DISMOUNT_VOLUME,
NULL, 0,
NULL, 0,
&dwBytesReturned,
NULL);
}
static BOOL PreventRemovalOfVolume(HANDLE hVolume, BOOL fPreventRemoval)
{
DWORD dwBytesReturned;
PREVENT_MEDIA_REMOVAL PMRBuffer;
PMRBuffer.PreventMediaRemoval = fPreventRemoval;
return DeviceIoControl( hVolume,
IOCTL_STORAGE_MEDIA_REMOVAL,
&PMRBuffer, sizeof(PREVENT_MEDIA_REMOVAL),
NULL, 0,
&dwBytesReturned,
NULL);
}
static int AutoEjectVolume(HANDLE hVolume)
{
DWORD dwBytesReturned;
return DeviceIoControl( hVolume,
IOCTL_STORAGE_EJECT_MEDIA,
NULL, 0,
NULL, 0,
&dwBytesReturned,
NULL);
}
BOOL EjectVolume(TCHAR cDriveLetter)
{
BOOL fAutoEject = FALSE;
HANDLE hVolume = OpenVolume(cDriveLetter);
if (hVolume == INVALID_HANDLE_VALUE)
return FALSE;
// Lock and dismount the volume.
if (LockVolume(hVolume) && DismountVolume(hVolume)) {
// Set prevent removal to false and eject the volume.
if (PreventRemovalOfVolume(hVolume, FALSE) && AutoEjectVolume(hVolume))
fAutoEject = TRUE;
}
// Close the volume so other processes can use the drive.
if (!CloseVolume(hVolume))
return FALSE;
if (fAutoEject) return TRUE;
else return FALSE;
}
|
