best strategy for preventing unnecessary oplock breaks on doubly open files

[tridge at samba.org]

Jeremy,

 > Great ! That looks easy - are you going to check it into Samba4 torture ?

not as-is, as it would fail against windows and Samba.

I'll check it in as a 'informational' test, reporting something like:

 "this server supports oplock upgrade on open file handles"

Cheers, Tridge