On 10/3/23 10:47 AM, Ming Lei wrote:
> On Sun, Oct 01, 2023 at 01:54:48PM -0500, Mike Christie wrote:
>> We are converting tcmu applications to ublk, but have systems with up
>> to 1k devices. This patch allows us to configure the ublks_max from
>> userspace with the ublks_max modparam.
>>
>> Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
>> ---
>> drivers/block/ublk_drv.c | 31 ++++++++++++++++++++++++++++++-
>> 1 file changed, 30 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
>> index 18e352f8cd6d..2833a81e05c0 100644
>> --- a/drivers/block/ublk_drv.c
>> +++ b/drivers/block/ublk_drv.c
>> @@ -2940,7 +2940,36 @@ static void __exit ublk_exit(void)
>> module_init(ublk_init);
>> module_exit(ublk_exit);
>>
>> -module_param(ublks_max, int, 0444);
>> +static int ublk_set_max_ublks(const char *buf, const struct kernel_param *kp)
>> +{
>> + unsigned int max;
>> + int ret;
>> +
>> + ret = kstrtouint(buf, 10, &max);
>> + if (ret)
>> + return ret;
>> +
>> + if (max > UBLK_MAX_UBLKS) {
>> + pr_warn("Invalid ublks_max. Max supported is %d\n",
>> + UBLK_MAX_UBLKS);
>> + return -EINVAL;
>> + }
>> +
>> + ublks_max = max;
>> + return ret;
>
> It might be nice to reuse builtin helper:
>
> return param_set_uint_minmax(buf, kp, 0, UBLK_MAX_UBLKS);
>
Was looking for something like that but missed it. Will
use.
>> +}
>> +
>> +static int ublk_get_max_ublks(char *buf, const struct kernel_param *kp)
>> +{
>> + return sysfs_emit(buf, "%d\n", ublks_max);
>> +}
>> +
>> +static const struct kernel_param_ops ublk_max_ublks_ops = {
>> + .set = ublk_set_max_ublks,
>> + .get = ublk_get_max_ublks,
>
> Same with above, '.get = param_get_int,' could be better.
>
Will do.
