brd: export module parameters
Export 'rd_nr', 'rd_size' and 'max_part' parameters to sysfs so user can know that how many devices are allowed, how big each device is and how many partitions are supported. If 'max_part' is 0, it means simply the device doesn't support partitioning. Also note that 'max_part' can be adjusted to power of 2 minus 1 form if needed. User should check this value after the module loading if he/she want to use that number correctly (i.e. fdisk, mknod, etc.). Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
parent
13868b76ab
commit
8892cbaf68
|
@ -436,11 +436,11 @@ static int rd_nr;
|
|||
int rd_size = CONFIG_BLK_DEV_RAM_SIZE;
|
||||
static int max_part;
|
||||
static int part_shift;
|
||||
module_param(rd_nr, int, 0);
|
||||
module_param(rd_nr, int, S_IRUGO);
|
||||
MODULE_PARM_DESC(rd_nr, "Maximum number of brd devices");
|
||||
module_param(rd_size, int, 0);
|
||||
module_param(rd_size, int, S_IRUGO);
|
||||
MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes.");
|
||||
module_param(max_part, int, 0);
|
||||
module_param(max_part, int, S_IRUGO);
|
||||
MODULE_PARM_DESC(max_part, "Maximum number of partitions per RAM disk");
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
|
||||
|
@ -578,9 +578,20 @@ static int __init brd_init(void)
|
|||
*/
|
||||
|
||||
part_shift = 0;
|
||||
if (max_part > 0)
|
||||
if (max_part > 0) {
|
||||
part_shift = fls(max_part);
|
||||
|
||||
/*
|
||||
* Adjust max_part according to part_shift as it is exported
|
||||
* to user space so that user can decide correct minor number
|
||||
* if [s]he want to create more devices.
|
||||
*
|
||||
* Note that -1 is required because partition 0 is reserved
|
||||
* for the whole disk.
|
||||
*/
|
||||
max_part = (1UL << part_shift) - 1;
|
||||
}
|
||||
|
||||
if ((1UL << part_shift) > DISK_MAX_PARTS)
|
||||
return -EINVAL;
|
||||
|
||||
|
|
Loading…
Reference in a new issue