Fwd: handle special file type in tmpfs

[Glen]

Hi Howard,

May I ask if you are using the tmpfs port by Rohit Jalan? A link to his 
work can be found on this page:
http://www.freebsd.org/projects/ideas/

I am currently using the BETA3 tmpfs port and have experienced an issue 
with the FIFO support for tmpfs. I believe that this is because the 
tmpfs_fifoops.c specifies an incomplete vnode operations vector 
(vop_vector) for tmpfs. The vop_vector allows you to specify all the 
vnode operations for a particular filesystem.

If you check out ufs/ufs_vnops.c it specifies a global vop vector for 
most file types and then a different vop_vector for FIFO file types. 
Rohit's tmpfs port does a similar thing. I have populated the tmpfs 
vop_vector in this port and FIFO seems to work a better although I 
haven't fully tested it yet.  Maybe this information helps you get to a 
solution.

I am keen to get tmpfs into the Freebsd tree and have been communicating 
with Rohit regarding this. He currently doesn't have time to do further 
improvements and I have offered to help get this tmpfs port into 
Freebsd. I am awaiting a response to this (we only started talking last 
week).

This port has a few outstanding items:

* MP safeness (some locking may be required). I have started testing 
tmpfs on an MP system.
* Security audit (not sure what's required for this)
* Quota support, ACL work is pending
* Two data I/O mechanisms are benchmarked, deciding which one to use is 
still pending

I may be looking to address these items over the coming weeks.

Regards,
Glen