On Mon, May 25, 2015 at 12:29:12PM -0400, Jude Nelson wrote:
...
> What I'm working on going is the following:
> * fork runfs to create eventfs, a RAM-backed userspace filesystem that
> looks and smells like tmpfs, but is designed such that (1) files and
> directories share fate with the process that creates them, and (2) the
> filesystem remembers the order in which files in a directory are created.
> We'd use it to implement reliable one-writer many-reader uevent packet
> multicast. Specifically, the eventfs would work like a tmpfs, but with the
> following different behaviors:
> -- a directory and its children only exist if the process that created it
> is still running. Once the process dies, the directory and its children
> are automatically removed.
> -- each directory contains an eventfs-managed "head" symlink that points to
> the newest-created regular file child
> -- each directory contains an eventfs-managed "tail" symlink that points to
> the oldest-created regular file child
> -- unlink()-ing "head" really unlinks the file that "head" points to, and
> causes "head" to point to the next-newest regular file child
> -- unlink()-ing "tail" really unlinks the file that "tail" points to, and
> causes "tail" to point to the next-oldest regular file

Just wondering what happens if process A creates a directory in
eventfs, process B makes it its working directory, and then process A
dies. Does process B end up with a nonexistent working directory?
umount won't let me do this. WOuld this be different?

-- hendrik