[PATCH] nvmet: fix mar and mor off-by-one errors

[Dennis Maisenbacher]

>> Cast the unsigned int values that are returned by bdev_max_open_zones and
>> bdev_max_active_zones into u32 vales which need to be decremented as the
>> returned values of the block layer helpers are not 0's based.
>> The cast to u32 is necessary because the size of unsigned int is
>> architecture dependent and a 0 reported by the block layer helpers
>> indicates no limit, thus it needs to be converted to 0xffffffff which
>> happens by underflowing the u32.
>
>unsigned int (in Linux, not the C standard) is not architecture
>dependent but always a 32-bit unsigned integer type.

Thanks for clarifying!

>But I'd much rather see an explicit check for 0 and conversion to
>0xffffffff anyway.  Yes, unsigned integer underflow is well defined,
>but having the explicit check explains much better to the read that it
>is intentional.
>
>Can you also add a Fixes tag, please?

Sure, makes sense. I will address your comments in v2.

Dennis