Re: [PATCH 3/7] rnbd: drop WRITE_SAME support

[Guoqing Jiang <guoqing.jiang@linux.dev>]

On 2/9/22 5:13 PM, Jinpu Wang wrote:
>>> --- a/drivers/block/rnbd/rnbd-srv.c
>>> +++ b/drivers/block/rnbd/rnbd-srv.c
>>> @@ -548,8 +548,7 @@ static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
>>>                cpu_to_le16(rnbd_dev_get_max_segs(rnbd_dev));
>>>        rsp->max_hw_sectors =
>>>                cpu_to_le32(rnbd_dev_get_max_hw_sects(rnbd_dev));
>>> -     rsp->max_write_same_sectors =
>>> -             cpu_to_le32(bdev_write_same(rnbd_dev->bdev));
>>> +     rsp->max_write_same_sectors = 0;
>> IIUC, I think we can delete max_write_same_sectors from rsp as well given
>> the earlier change in setup_request_queue and rnbd_clt_set_dev_attr.
> No, I don't think it's a good idea, we need to keep the protocol
> compatible, so client for old kernel version
> won't be confused.

Fair enough. Then I guess it is better to add obsolete_ prefix like 
obsolete_rotational.

Thanks,
Guoqing