[PATCH] lib/tdb: new locking hook.

[tridge at samba.org]

Hi Rusty,

 > This obsoletes the *mark and *nonblock calls, by allowing the user
 > to do fancy work replacing, recording or faking fcntl locks.  This
 > should make ctdb's life easier. 

that is OK, but I'd like to see this integrated and tested in ctdb
first, as ctdb is the one that uses the mark locks.

Ronnie, have you looked at this?

 > We could avoid adding YA open function if we didn't want to allow
 > non-blocking open, or complete tracking of all lock operations.

I don't think the new open is needed just yet, unless you have a use
in mind for it. The way ctdb uses the 'mark' locks is not at open
time, but when the tdb is already attached and ctdb wants a child
process to handle the locking. 

Cheers, Tridge