shared stat cache

[tridge at samba.org]

Volker,

 >  A file is opened for the first time. This fixes the stat entry
 >  returned by call_trans2qfilenameinfo. writes while the file is open
 >  does *not* affect the last_write timestamp returned.
 > 
 >  Another client opens the file and writes. And still there is no
 >  change in the last_write timestamp returned.
 > 
 >  Any connection having written *and* closed the file updates
 >  the last_write timestamp on the file.

Thanks for looking at this Volker!

It might be worthwhile checking if this is a hard set of semantics, or
the result of an unflushed cache. For example, if you wait for a
minute or two will the write time then update?

Cheers, Tridge