[PATCH RFC 3/4] block: Support atomic writes limits for stacked devices

[John Garry]

On 12/09/2024 14:16, Christoph Hellwig wrote:
> On Tue, Sep 03, 2024 at 03:07:47PM +0000, John Garry wrote:
>> +	} else if (t->features & BLK_FEAT_ATOMIC_WRITES) {
>> +		t->atomic_write_hw_max = min_not_zero(t->atomic_write_hw_max,
>> +						b->atomic_write_hw_max);
>> +		t->atomic_write_boundary_sectors =
>> +					min_not_zero(t->atomic_write_boundary_sectors,
>> +						b->atomic_write_boundary_sectors);
>> +		t->atomic_write_hw_unit_min = max(t->atomic_write_hw_unit_min,
>> +						b->atomic_write_hw_unit_min);
>> +		t->atomic_write_hw_unit_max =
>> +					min_not_zero(t->atomic_write_hw_unit_max,
>> +						b->atomic_write_hw_unit_max);
> 
> Maybe split this into a helper to make the code more readable?

Yeah, I will do.

I was reworking this anyway.

So far I am not supporting a stripe unit with which is not a power-of-2. 
But that is too restrictive. And lifting that restriction makes 
calculating atomic write limits more complicated.

> 
> Otherwise this looks good to me.

cheers