illumos gate

After correcting #3223, it was observed that a Windows 7 client, when listing a directory with about 27,500 subdirectories, the client would get all the way to the end of the directory and then issue an "NT Trans. Notify" request to wait for any change in that directory (or any of its subdirectories). That "NT Trans. Notify" request is expected to block for a while, but we return it immediately, after which the client comes back and lists the entire directory again.

This causes the client spam us with directory listing requests. Since these are typically answered entirely from cache, this is often reported as "high CPU utilization".