On Mon, Aug 28, 2017 at 10:00:35AM +0300, Sagi Grimberg wrote: >> This helper allows reinserting a bio into a new queue without much >> overhead, but requires all queue limits to be the same for the upper >> and lower queues, and it does not provide any recursion preventions, >> which requires the caller to not split the bio. > > Isn't the same limits constraint too restrictive? > > Say I have two paths to the same namespace via two different HBAs, each > with its own virt_boundary capability for example? That would require us > to split failover bio wouldn't it? Uh oh - different transports for the same subsystem will be intereting. For one it's not specified anywhere so I'd like to kick off a discussion on the working group mailing list about it. That being said ->make_request basically doesn't care about actual limits at all, it mostly care about support features (e.g. discard, fua, etc). So I think a lot of these limits could porbably be lifted, but I'd need to add the check to generic_make_request_checks back. >> +/* >> + * Fast-path version of generic_make_request. > > generic_make_request is also called in the fast-path, maybe reword it > to: "Fast version of generic_make_request" Yeah. Maybe generic_make_request_direct or direct_make_request is a better name as it describes the recursion avoidance bypassing a little better.
