From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: include/linux/pagemap.h: rename arguments to find_subpage This isn't just a random struct page, it's known to be a head page, and calling it head makes the function better self-documenting. The pgoff_t is less confusing if it's named index instead of offset. Also add a couple of comments to explain why we're doing various things. Link: http://lkml.kernel.org/r/20200318140253.6141-3-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Acked-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/pagemap.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/include/linux/pagemap.h~mm-rename-arguments-to-find_subpage +++ a/include/linux/pagemap.h @@ -333,14 +333,19 @@ static inline struct page *grab_cache_pa mapping_gfp_mask(mapping)); } -static inline struct page *find_subpage(struct page *page, pgoff_t offset) +/* + * Given the page we found in the page cache, return the page corresponding + * to this index in the file + */ +static inline struct page *find_subpage(struct page *head, pgoff_t index) { - if (PageHuge(page)) - return page; + /* HugeTLBfs wants the head page regardless */ + if (PageHuge(head)) + return head; - VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(PageTail(head), head); - return page + (offset & (compound_nr(page) - 1)); + return head + (index & (compound_nr(head) - 1)); } struct page *find_get_entry(struct address_space *mapping, pgoff_t offset); _
