> if (unlikely(error)) {
> + unsigned int pageoff = offset_in_page(file_offset);
> + /*
> + * Let the filesystem know what portion of the current page
> + * failed to map. If the page wasn't been added to ioend, it
> + * won't be affected by I/O completion and we must unlock it
> + * now.
> + */
> + if (wpc->ops->discard_page)
> + wpc->ops->discard_page(page, pageoff);
I don't think we need the pageoff variable here. Also it would
seem more natural to pass the full file_offset offset instead of
having to recreate it in the file system.
