Re: [Patch] invalidate range of pages after direct IO write

[Zach Brown <zach.brown@oracle.com>]

>> But this won't happen if next
>>started as 0 and we didn't update it.  I don't know if retrying is the
>>intended behaviour or if we care that the start == 0 case doesn't do it.
> 
> 
> Good point.  Let's make it explicit?

Looks great.  I briefly had visions of some bitfield to pack the three
boolean ints we have and then quickly came to my senses. :)

I threw together those other two patches that work with ranges around
direct IO.  (unmaping before r/w and writing and waiting before reads).
 rc3-mm1 is angry with my test machine so they're actually against
current -bk with this first invalidation patch applied.  I hope that
doesn't make life harder than it needs to be.  I'll send them under
seperate cover.

- z