On Mon, Jun 7, 2021 at 11:34 PM Enrico Weigelt, metux IT consult
[off-list ref] wrote:

On 02.06.21 17:50, Alessio Balsini wrote:

quoted

quoted

A possible use case is fuse fd passthrough being developed
by Alessio Balsini [1] where underlying file system fd can be saved in
this file store.

oh, this could be quite what I'm currently intending do implement
(just considered 9p instead of fuse as it looks simpler to me):

I'd like the server being able to directly send an already opened fd to
the client (in response to it calling open()), quite like we can send
fd's via unix sockets.

The primary use case of that is sending already prepared fd's (eg. an
active network connection, locked-down file fd, a device that the client
can't open himself, etc).

Is that what you're working on ?

If the server and client run on the same kernel, then yes, the current
RFC supports your use case as well, E.g.,
1. the server opens a file, saves the FD to the kernel, and passes the
IDR to the client.
2. the client retrieves the FD from the kernel

Does it match your use case?

Cheers,
Tao

-- 
Into Sth. Rich & Strange