mm: convert find_get_entry to return the head page
There are only four callers remaining of find_get_entry().
get_shadow_from_swap_cache() only wants to see shadow entries and doesn't
care about which page is returned. Push the find_subpage() call into
find_lock_entry(), find_get_incore_page() and pagecache_get_page().
[willy@infradead.org: fix oops]
Link: https://lkml.kernel.org/r/20200914112738.GM6583@casper.infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: https://lkml.kernel.org/r/20200910183318.20139-7-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/swap_state.c b/mm/swap_state.c
index c79e224..f24f2ce 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -431,8 +431,10 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
struct swap_info_struct *si;
struct page *page = find_get_entry(mapping, index);
- if (!xa_is_value(page))
+ if (!page)
return page;
+ if (!xa_is_value(page))
+ return find_subpage(page, index);
if (!shmem_mapping(mapping))
return NULL;