J. Bruce Fields wrote:

>On Mon, Jun 12, 2006 at 01:25:43AM -0400, Wendy Cheng wrote:
>  
>
>>2. Adding a new flag into "exportfs" command, say "h", such that
>>
>>   "exportfs -uh *:/export_path"
>>
>>would un-export the entry and drop the NLM locks associated with the
>>entry.
>>    
>>
>
>What does the kernel interface end up looking like in that case?
>
>  
>
Happy to see this new exportfs command gets positive response - it was 
our original pick too.

Uploaded is part of a draft version of 2.4 base kernel patch - we're 
cleaning up 2.6 patches at this moment. It basically adds a new export 
flag (NFSEXP_FOLOCK - note that ex_flags is an int but is currently only 
defined up to 16 bits) so nfs-util and kernel can communicate.

The nice thing about this approach is the recovery part - the take-over 
server can use the counter part command to export and set grace period 
for one particular interface within the same system call.

-- Wendy