mm/filemap: rename find_get_entry to mapping_get_entry

find_get_entry doesn't "find" anything.  It returns the entry at a
particular index.

Link: https://lkml.kernel.org/r/20201112212641.27837-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/filemap.c

@@ -1659,7 +1659,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
 EXPORT_SYMBOL(page_cache_prev_miss);
 
 /*
- * find_get_entry - find and get a page cache entry
+ * mapping_get_entry - Get a page cache entry.
  * @mapping: the address_space to search
  * @index: The page cache index.
  *
@@ -1671,7 +1671,8 @@ EXPORT_SYMBOL(page_cache_prev_miss);
  *
  * Return: The head page or shadow entry, %NULL if nothing is found.
  */
-static struct page *find_get_entry(struct address_space *mapping, pgoff_t index)
+static struct page *mapping_get_entry(struct address_space *mapping,
+		pgoff_t index)
 {
 	XA_STATE(xas, &mapping->i_pages, index);
 	struct page *page;
@@ -1747,7 +1748,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
 	struct page *page;
 
 repeat:
-	page = find_get_entry(mapping, index);
+	page = mapping_get_entry(mapping, index);
 	if (xa_is_value(page)) {
 		if (fgp_flags & FGP_ENTRY)
 			return page;