On Thu 19-07-18 18:21:23, Ming Lei wrote:
> On Thu, Jul 19, 2018 at 11:39:18AM +0200, Martin Wilck wrote:
> > bio_iov_iter_get_pages() returns only pages for a single non-empty
> > segment of the input iov_iter's iovec. This may be much less than the number
> > of pages __blkdev_direct_IO_simple() is supposed to process. Call
>
> In bio_iov_iter_get_pages(), iov_iter_get_pages() supposes to retrieve
> as many as possible pages since both 'maxsize' and 'maxpages' are provided
> to cover all.
>
> So the question is why iov_iter_get_pages() doesn't work as expected?
Well, there has never been a promise that it will grab *all* pages in the
iter AFAIK. Practically, I think that it was just too hairy to implement in
the macro magic that iter processing is... Al might know more (added to
CC).
Honza
--
Jan Kara <[email protected]>
SUSE Labs, CR
