On 3/30/23 3:22?AM, Damien Le Moal wrote:
> On 3/30/23 14:51, Chaitanya Kulkarni wrote:
>> Right now we don't check for valid module parameter value for
>> submit_queue, that allows user to set negative values.
>>
>> Add a callback null_set_submit_queues() to error out when submit_queue
>> value is < 1 before module is loaded.
>>
>> Signed-off-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
>> ---
>> drivers/block/null_blk/main.c | 12 +++++++++++-
>> 1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
>> index cf6937f4cfa1..9e3df92d0b98 100644
>> --- a/drivers/block/null_blk/main.c
>> +++ b/drivers/block/null_blk/main.c
>> @@ -100,8 +100,18 @@ static int g_no_sched;
>> module_param_named(no_sched, g_no_sched, int, 0444);
>> MODULE_PARM_DESC(no_sched, "No io scheduler");
>>
>> +static int null_set_submit_queues(const char *s, const struct kernel_param *kp)
>> +{
>> + return null_param_store_int(s, kp->arg, 1, INT_MAX);
>> +}
>> +
>> +static const struct kernel_param_ops null_submit_queues_param_ops = {
>> + .set = null_set_submit_queues,
>> + .get = param_get_int,
>> +};
>> +
>> static int g_submit_queues = 1;
>> -module_param_named(submit_queues, g_submit_queues, int, 0444);
>> +device_param_cb(submit_queues, &null_submit_queues_param_ops, &g_submit_queues, 0444);
>> MODULE_PARM_DESC(submit_queues, "Number of submission queues");
>>
>> static int g_poll_queues = 1;
>
> I would do this:
>
> +#define NULL_PARAM(_name, _min, _max) \
> +static int null_param_##_name##_set(const char *s, \
> + const struct kernel_param *kp) \
> +{ \
> + return null_param_store_int(s, kp->arg, _min, _max); \
> +} \
> + \
> +static const struct kernel_param_ops null_##_name##_param_ops = { \
> + .set = null_param_##_name##_set, \
> + .get = param_get_int, \
> +}
> +
>
> And then have:
>
> +NULL_PARAM(submit_queues, 1, INT_MAX);
> +NULL_PARAM(poll_queues, 1, num_online_cpus());
> +NULL_PARAM(queue_mode, NULL_Q_BIO, NULL_Q_MQ);
> +NULL_PARAM(gb, 1, INT_MAX);
> +NULL_PARAM(bs, 512, 4096);
> +NULL_PARAM(max_sectors, 1, INT_MAX);
> +NULL_PARAM(irqmode, NULL_IRQ_NONE, NULL_IRQ_TIMER);
> +NULL_PARAM(hw_qdepth, 1, INT_MAX);
>
> That can be done in a single patch and is overall a lot less code.
Agree, let's please try and reduce the number of patches in a series
when it's not really useful to split things up.
--
Jens Axboe
