[Samba] Slow FIND_FIRST2 response

[Ryan Bair]

I'm running Samba 4.0.7 on CentOS 6.4 running double duty as DC and file
server.

OS X clients are taking a _long_ time to list long directories. One
directory with 10K entries is taking 3-4 minutes to display the entries in
Finder.

I captured a few seconds worth of packets and noticed that it's doing three
requests per file:
1. NTCreateAndX - just opens the file
2. Close
3. FIND_FIRST2 - to look for the resource fork

The first two happen extremely fast, the 3rd one is the kicker. Samba is
taking about 0.025 seconds to return a response to the client (usually no
such file status). Multiple that by 10K requests and you have a few minutes
on your hands.

I'm guessing the problem is that Samba must honor case-insensitivity for
the lookup which is likely an expensive operation. Is there anyway to speed
this up?