On 09/12/2019 03:09 PM, André Almeida wrote: > Hello Matthew, > > On 9/12/19 1:19 PM, Matthew Wilcox wrote: >> On Wed, Sep 11, 2019 at 11:46:36AM -0300, André Almeida wrote: >>> >>> -static int nr_devices = 1; >>> +static unsigned int nr_devices = 1; >>> module_param(nr_devices, int, 0444); >> >> ^^^ you forgot to change the module_param to match >> >>> + if (!nr_devices) { >>> + pr_err("null_blk: invalid number of devices\n"); >>> + return -EINVAL; >>> + } >> >> I don't think this is necessary. >> > > Could you explain why you don't think is necessary? As I see, the module > can't be used without any /dev/nullb* device, so why we should load it? > > Thanks, > André > I think Matthew is right here. I think module can be loaded with nr_devices=0. Did you get a chance to test nr_device=0 condition ? Also, did you get a chance to test this patch with all the possible conditions ?