From 63ec1973ddf3eb70feb5728088ca190f1af449cb Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 13 Oct 2020 16:51:38 -0700 Subject: mm/shmem: return head page from find_lock_entry Convert shmem_getpage_gfp() (the only remaining caller of find_lock_entry()) to cope with a head page being returned instead of the subpage for the index. [willy@infradead.org: fix BUG()s] Link https://lore.kernel.org/linux-mm/20200912032042.GA6583@casper.infradead.org/ Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Cc: Alexey Dobriyan Cc: Chris Wilson Cc: Huang Ying Cc: Hugh Dickins Cc: Jani Nikula Cc: Johannes Weiner Cc: Matthew Auld Cc: William Kucharski Link: https://lkml.kernel.org/r/20200910183318.20139-8-willy@infradead.org Signed-off-by: Linus Torvalds --- include/linux/pagemap.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 9d282fe6700d..5176009e4ffa 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -372,6 +372,15 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping, mapping_gfp_mask(mapping)); } +/* Does this page contain this index? */ +static inline bool thp_contains(struct page *head, pgoff_t index) +{ + /* HugeTLBfs indexes the page cache in units of hpage_size */ + if (PageHuge(head)) + return head->index == index; + return page_index(head) == (index & ~(thp_nr_pages(head) - 1UL)); +} + /* * Given the page we found in the page cache, return the page corresponding * to this index in the file -- cgit v1.2.3