[9fans] implmenting /mnt/9/clone

["Ronald G. Minnich" <rminnich@lanl.gov>]

I'm playing around with the p9p ramfs server, and was wondering about the 
best way to implement a file for clone. 

e.g. I have /mnt/9/clone, and when clone is opened, I want to to mean that
/mnt/9/1/ctl is created and fid for that file returned to client, and the
next open of clone gets /mnt/9/2/ctl, etc. As usual, a read of the ctl 
would return the # for that ctl file. 

I can think of a couple of ways to 
do it, with the simplest involving:
- when clone is opened, create #/ctl, e.g. 3/ctl
- swap the qids for clone and the #/ctl file

Any comments on this, or hidden gotchas, or ...

I'm pretty sure this would work for Linux 9p clients, but am not sure 
about the overal cleanliness of this approach, or if there is some better 
way to do it.

ron