On Sun, Jul 05, 2020 at 03:12:50PM -0600, Jens Axboe wrote: > On 7/5/20 3:09 PM, Matthew Wilcox wrote: > > On Sun, Jul 05, 2020 at 03:00:47PM -0600, Jens Axboe wrote: > >> On 7/5/20 12:47 PM, Kanchan Joshi wrote: > >>> From: Selvakumar S <selvakuma.s1@xxxxxxxxxxx> > >>> > >>> For zone-append, block-layer will return zone-relative offset via ret2 > >>> of ki_complete interface. Make changes to collect it, and send to > >>> user-space using cqe->flags. > > I'm surprised you aren't more upset by the abuse of cqe->flags for the > > address. > > Yeah, it's not great either, but we have less leeway there in terms of > how much space is available to pass back extra data. > > > What do you think to my idea of interpreting the user_data as being a > > pointer to somewhere to store the address? Obviously other things > > can be stored after the address in the user_data. > > I don't like that at all, as all other commands just pass user_data > through. This means the application would have to treat this very > differently, and potentially not have a way to store any data for > locating the original command on the user side. I think you misunderstood me. You seem to have thought I meant "use the user_data field to return the address" when I actually meant "interpret the user_data field as a pointer to where userspace wants the address stored".
