[...]
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.
This statement is generally correct. However what application would be
interested in speaking raw nvme to a device and gaining performance that
is even higher than the block layer (which is great to begin with)?
First thing that comes to mind is a high-end storage array, where
dual-ported drives are considered to be the standard. I could argue the
same for a high-end oracle appliance or something like that... Although
in a lot of cases, each nvme port will connect to a different host...
What are the use-cases that need this interface that are the target
here? Don't remember seeing this come up in the cover-letter or previous
iterations...
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.
What do you mean by "they be flagged as such"?
