Platform SDK: Win32 API |
Retrieves the current lock level and permissions on the specified drive.
mov ax, 440Dh ; generic IOCTL mov bl, DriveNum ; see below mov ch, 08h ; device category (must be 08h) mov cl, 70h ; Get Current Lock State int 21h jc error
Clears the carry flag and sets the AX and CX registers to these values if successful:
AX | Current lock level. It may be either 0, 1, 2 or 3. If the volume is not locked, AX contains – 1 | |
CX | Lock permissions. The bits have the following form: | |
Bit | Meaning | |
---|---|---|
0 | 0 = Write operations are failed. | |
0 | 1 = Write operations are allowed, unless they are blocked by the lock level. | |
1 | 0 = New file mapping are allowed, unless they are blocked by the lock level. | |
1 | 1 = New file mapping are failed. | |
2 | 1 = The volume is locked for formatting. |
The lock level and the permissions determine the kind of access processes other than the lock owner have to the volume while it is locked. The following operations are allowed by processes other than lock owner at each lock level.
Level | Operations |
---|---|
0 | Read operations, write operations, and new file mappings are failed. |
1 | Read operations are allowed. Write operations and new file mappings are either allowed or failed based on permissions. |
2 | Read operations are allowed. Write operations and new file mappings are either failed or blocked based on permissions. |
3 | Read operations are blocked. Write operations and new file mappings are either failed or blocked based on permissions. |