On Fri, Jul 05, 2024 at 01:35:18PM +0000, Chuck Lever III wrote: > > > > On Jul 5, 2024, at 1:18 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > > > On Thu, Jul 04, 2024 at 02:31:46PM -0400, Mike Snitzer wrote: > >> Some new layout misses the entire point of having localio work for > >> NFSv3 and NFSv4. NFSv3 is very ubiquitous. > > > > I'm getting tird of bringing up this "oh NFSv3" again and again without > > any explanation of why that matters for communication insides the > > same Linux kernel instance with a kernel that obviously requires > > patching. Why is running an obsolete protocol inside the same OS > > instance required. Maybe it is, but if so it needs a very good > > explanation. > > I agree: I think the requirement for NFSv3 in this situation > needs a clear justification. Both peers are recent vintage > Linux kernels; both peers can use NFSv4.x, there's no > explicit need for backwards compatibility in the use cases > that have been provided so far. > > Generally I do agree with Neil's "why not NFSv3, we still > support it" argument. But with NFSv4, you get better locking > semantics, delegation, pNFS (possibly), and proper protocol > extensibility. There are really strong reasons to restrict > this facility to NFSv4. NFSv3 is needed because NFSv3 is used to initiate IO to NFSv3 knfsd on the same host.
