On Tue, Sep 01, 2020 at 08:44:14PM +0100, David Howells wrote: > Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > > > Note that I've been > > > passing the number of pages to read in rac->_nr_pages, and then saving it > > > and changing it certain points, e.g. page_cache_readahead_unbounded(). > > > > I do not like this. You're essentially mutating the meaning of _nr_pages > > as the ractl moves down the stack, and that's going to lead to bugs. > > I'd keep it as a separate argument. > > The meaning isn't specified in linux/pagemap.h. Can you adjust the comments > on the struct and on readahead_count() to make it more clear what the value > represents? It's intentionally not documented. This documentation is for the filesystem author, who should not be looking at it. Neither should you :-P
