On Wed, Jul 13, 2022 at 02:00:56PM +0300, Sagi Grimberg wrote: > I view uring passthru somewhat as a different thing than sending SG_IO > ioctls to dm-mpath. But it can be argued otherwise. > > BTW, the only consumer of it that I'm aware of commented that he > expects dm-mpath to retry SG_IO when dm-mpath retry for SG_IO submission > was attempted (https://www.spinics.net/lists/dm-devel/msg46924.html). Yeah. But the point is that if we have a path failure, the kernel will pick a new path next time anyway, both in dm-mpath and nvme-mpath. > I still think that there is a problem with the existing semantics for > passthru requests over mpath device nodes. > > Again, I think it will actually be cleaner not to expose passthru > devices for mpath at all if we are not going to support retry/failover. I think they are very useful here. Users of passthrough interface need to be able to retry anyway, even on non-multipath setups. And a dumb retry will do the right thing.
