> - /*
> - * Operate on a partial iter trimmed to the extent we were called for.
> - * We'll update the iter in the dio once we're done with this extent.
> - */
> - iter = *dio->submit.iter;
> - iov_iter_truncate(&iter, length);
> + /* Operate on a partial iter trimmed to the extent we were called for */
> + iov_iter_truncate(dio->submit.iter, length);
I think the comment could be kept a little more verbose given that the
scheme isn't exactly obvious. Also I'd move the initialization of
orig_count here to keep it all together. E.g.
/*
* Save the original count and trim the iter to just the extent we
* are operating on right now. The iter will be re-expanded once
* we are done.
*/
orig_count = iov_iter_count(dio->submit.iter);
iov_iter_truncate(dio->submit.iter, length);
>
> - nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES);
> - if (nr_pages <= 0)
> + nr_pages = iov_iter_npages(dio->submit.iter, BIO_MAX_PAGES);
> + if (nr_pages <= 0) {
> + iov_iter_reexpand(dio->submit.iter, orig_count);
> return nr_pages;
> + }
Can we stick to a single iov_iter_reexpand call? E.g. turn this into
if (nr_pages <= 0) {
ret = nr_pages;
goto out;
}
and then have the out label at the very end call iov_iter_reexpand.
> iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
> }
> + /* Undo iter limitation to current extent */
> + iov_iter_reexpand(dio->submit.iter, orig_count - copied);
> return copied ? copied : ret;
In iomap-for-next this is:
if (copied)
return copied;
return ret;
so please rebase to iomap-for-next for the next spin.
