On 3/16/22 7:52 AM, Sagi Grimberg wrote: > >>>>>>> No one cares that this has no multipathing capabilities what-so-ever? >>>>>>> despite being issued on the mpath device node? >>>>>>> >>>>>>> I know we are not doing multipathing for userspace today, but this >>>>>>> feels like an alternative I/O interface for nvme, seems a bit cripled >>>>>>> with zero multipathing capabilities... > > [...] > >> Got it, thanks. Passthrough (sync or async) just returns the failure >> to user-space if that fails. >> No attempt to retry/requeue as the block path does. > > I know, and that was my original question, no one cares that this > interface completely lacks this capability? Maybe it is fine, but > it is not a trivial assumption given that this is designed to be more > than an interface to send admin/vs commands to the controller... Most people don't really care about or use multipath, so it's not a primary goal. For passthrough, most of request types should hit the exact target, I would suggest that if someone cares about multipath for specific commands, that they be flagged as such. -- Jens Axboe