Re: [PATCH V2 0/4] 9p: convert to the new mount API

[Dominique Martinet <asmadeus@codewreck.org>]

Eric Sandeen wrote on Thu, Aug 14, 2025 at 11:55:20AM -0500:
> >> I was able to test this to some degree, but I am not sure how to test
> >> all transports; there may well be bugs here. It would be great to get
> >> some feedback on whether this approach seems reasonable, and of course
> >> any further review or testing would be most welcome.
> > 
> > I still want to de-dust my test setup with rdma over siw for lack of
> > supported hardware, so I'll try to give it a try, but don't necessarily
> > wait for me as I don't know when that'll be..
> 
> Any news on testing? :)

Thanks for the prompting, that's the kind of things I never get around
to if not reminded...

I got this to run with a fedora-based host (unlike debian siw is
built-in):

- host side
```
$ sudo modprobe siw
$ sudo rdma link add siw0 type siw netdev br0
(sanity check)
$ ibv_devices
    device          	  node GUID
    ------          	----------------
    siw0            	020000fffe000001
( https://github.com/chaos/diod build)
$ ./configure --enable-rdma --disable-auth && make -j
(diod run, it runs rdma by default; not squashing as root fails with
  rdma because of the ib_safe_file_access check:
  [611503.258375] uverbs_write: process 1490213 (diod) changed security contexts after opening file descriptor, this is not allowed.
)
$ sudo ./diod -f -e /tmp/linux-test/ --no-auth -U root -S 
```
- guest side (with -net user)
```
# modprobe siw
# rdma link add siw0 type siw netdev eth0
# mount -t 9p -o trans=rdma,aname=/tmp/linux-test <hostip> /mnt
```

I've tested both the new and old mount api (with util-linux mount and
busybox mount) and it all seems in order to me;
as discussed in the other part of the thread we're now failing on
unknown options but I think that's a feature and we can change that if
someone complains.

> As for "waiting for you," I assume that's more for your maintainer peers
> than for me? I'm not sure if this would go through Christian (cc'd) or
> through you?

Sorry, I wasn't paying attention and confused you with another Eric
(Van Hensbergen) who is a 9p maintainer, so I was thinking you'd take
the patches, but that wasn't correct.
And that's after seeing your name all the time in #xfs, I'm sorry..

Christian is "just" a reviewer (for now!), and none of the other
maintainers pick much up lately, so I'll give this a second look and
take the patches.
Linus just closed up 6.17-rc1 so I guess this will get in 6.18 in the
next cycle, unless there'd be a reason to hurry?

Thanks,
-- 
Dominique Martinet | Asmadeus