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| author | Namhyung Kim <namhyung@gmail.com> | 2011-05-26 21:06:50 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2011-05-26 21:06:50 +0200 |
| commit | 8892cbaf686fb18a5f0558b9fd7773b32c0c7852 (patch) | |
| tree | d42261b88e9ead68894e226d8d9afc838fa7cfb1 /drivers/block | |
| parent | 13868b76ab8135389fe1d8cf1c6a4847c9fef0a7 (diff) | |
| download | linux-8892cbaf686fb18a5f0558b9fd7773b32c0c7852.tar.gz linux-8892cbaf686fb18a5f0558b9fd7773b32c0c7852.tar.bz2 linux-8892cbaf686fb18a5f0558b9fd7773b32c0c7852.zip | |
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>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/brd.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/block/brd.c b/drivers/block/brd.c index d904d0da2928..dba1c32e1ddf 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -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; |