Re: srvfs: file system for posting open file descriptors into fs namespace

From: Al Viro
Date: Fri Aug 07 2020 - 12:23:15 EST

On Fri, Aug 07, 2020 at 01:09:30PM +0200, Enrico Weigelt, metux IT consult wrote:
> Hello folks,
> here's the first version of my "srvfs" implementation - a synthentic
> filesystem which allows a process to "publish" an open file descriptor
> into the file system, so other processes can continue from there, with
> whatever state the fd is already in.
> This is a concept from Plan9. The main purpose is allowing applications
> "dialing" some connection, do initial handshakes (eg. authentication)
> and then publish the connection to other applications, that now can now
> make use of the already dialed connection.

Yeah, but... Linux open() always gets a new struct file instance; how
do you work around that? Some variant of ->atomic_open() API change?
Details, please.