4.8 ffs_dirpref problem

[Don Lewis]

On 17 Nov, Ken Marx wrote:
> 
> Don Lewis wrote:

>> Since I probably won't have time to get anything different tested before
>> the -CURRENT code freeze, do you have any objections if I just MFC the
>> code that I previously committed to -CURRENT?  It certainly seems to
>> perform better than the original code which is still in 4-STABLE.

> Don, any fine points you put on our corse level of testing here
> are fine with us. I belive any of the versions you suggest will
> keep us well out of the crippling behavior that originally brought
> this up.

Ok, I'll do the commit as soon as I can do some testing on my -STABLE
box.

> I was able to run a couple more tests here, and *belive* that the
> fix to the hash table in vfs_bio.c will provide some relief
> for cg block searches when things do fall into the linear search case.

I'll see about cranking out patch to use a Fibonacci hash.  It'll
probably be a little while before I can find sufficient time, though.