On 2 Feb 2021, at 14:24, Dan Aloni wrote:

On Tue, Feb 02, 2021 at 01:52:10PM -0500, Anna Schumaker wrote:

quoted

You're welcome! I'll try to remember to CC him on future versions
On Tue, Feb 2, 2021 at 1:51 PM Chuck Lever [off-list ref] wrote:

quoted

I want to ensure Dan is aware of this work. Thanks for posting, Anna!

Thanks Anna and Chuck. I'm accessing and monitoring the mailing list via
NNTP and I'm also on #linux-nfs for chatting (da-x).

I see srcaddr was already discussed, so the patches I'm planning to send
next will be based on the latest version of your patchset and concern
multipath.

What I'm going for is the following:

- Expose transports that are reachable from xprtmultipath. Each in its
  own sub-directory, with an interface and status representation similar
  to the top directory.
- A way to add/remove transports.
- Inspiration for coding this is various other things in the kernel that
  use configfs, perhaps it can be used here too.

Also, what do you think would be a straightforward way for a userspace
program to find what sunrpc client id serves a mountpoint? If we add an
ioctl for the mountdir AFAIK it would be the first one that the NFS
client supports, so I wonder if there's a better interface that can work
for that.

I'm a fan of adding an ioctl interface for userspace, but I think we'd
better avoid using NFS itself because it would be nice to someday implement
an NFS "shutdown" for non-responsive servers, but sending any ioctl to the
mountpoint could revalidate it, and we'd hang on the GETATTR.

Maybe we can figure out a way to expose the superblock via sysfs for each
mount.

Ben