Re: [PATCH v5 01/13] mm: Fix the return type of __do_page_cache_readahead

From: Matthew Wilcox
Date: Thu Feb 13 2020 - 23:21:40 EST


On Thu, Feb 13, 2020 at 07:19:53PM -0800, John Hubbard wrote:
> On 2/10/20 5:03 PM, Matthew Wilcox wrote:
> > @@ -161,7 +161,7 @@ unsigned int __do_page_cache_readahead(struct address_space *mapping,
> > unsigned long end_index; /* The last page we want to read */
> > LIST_HEAD(page_pool);
> > int page_idx;
>
>
> What about page_idx, too? It should also have the same data type as nr_pages, as long as
> we're trying to be consistent on this point.
>
> Just want to ensure we're ready to handle those 2^33+ page readaheads... :)

Nah, this is just a type used internally to the function. Getting the
API right for the callers is the important part.