On Mon, Sep 11, 2017 at 12:07:23AM +0100, Al Viro wrote: > BTW, another problem I see there is that iomap_dio_actor() should *NOT* > assume that do-while loop in there will always manage to shove 'length' > bytes out in case of success. That is simply not true for pipe-backed > destination. And I'm not sure if outright failures halfway through > are handled correctly. What does it need a copy of dio->submit.iter for, > anyway? Why not work with dio->submit.iter directly? > --
So that we only walk the pagetables and pin down the pages that we can actually use in this iteration.
