filemap: convert some unsigned long to pgoff_t

Convert some 'unsigned long' to pgoff_t.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 8a83537..862fc07 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -84,11 +84,11 @@
 typedef int filler_t(void *, struct page *);
 
 extern struct page * find_get_page(struct address_space *mapping,
-				unsigned long index);
+				pgoff_t index);
 extern struct page * find_lock_page(struct address_space *mapping,
-				unsigned long index);
+				pgoff_t index);
 extern struct page * find_or_create_page(struct address_space *mapping,
-				unsigned long index, gfp_t gfp_mask);
+				pgoff_t index, gfp_t gfp_mask);
 unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
 			unsigned int nr_pages, struct page **pages);
 unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
@@ -99,41 +99,42 @@
 /*
  * Returns locked page at given index in given cache, creating it if needed.
  */
-static inline struct page *grab_cache_page(struct address_space *mapping, unsigned long index)
+static inline struct page *grab_cache_page(struct address_space *mapping,
+								pgoff_t index)
 {
 	return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
 }
 
 extern struct page * grab_cache_page_nowait(struct address_space *mapping,
-				unsigned long index);
+				pgoff_t index);
 extern struct page * read_cache_page_async(struct address_space *mapping,
-				unsigned long index, filler_t *filler,
+				pgoff_t index, filler_t *filler,
 				void *data);
 extern struct page * read_cache_page(struct address_space *mapping,
-				unsigned long index, filler_t *filler,
+				pgoff_t index, filler_t *filler,
 				void *data);
 extern int read_cache_pages(struct address_space *mapping,
 		struct list_head *pages, filler_t *filler, void *data);
 
 static inline struct page *read_mapping_page_async(
 						struct address_space *mapping,
-					     unsigned long index, void *data)
+						     pgoff_t index, void *data)
 {
 	filler_t *filler = (filler_t *)mapping->a_ops->readpage;
 	return read_cache_page_async(mapping, index, filler, data);
 }
 
 static inline struct page *read_mapping_page(struct address_space *mapping,
-					     unsigned long index, void *data)
+					     pgoff_t index, void *data)
 {
 	filler_t *filler = (filler_t *)mapping->a_ops->readpage;
 	return read_cache_page(mapping, index, filler, data);
 }
 
 int add_to_page_cache(struct page *page, struct address_space *mapping,
-				unsigned long index, gfp_t gfp_mask);
+				pgoff_t index, gfp_t gfp_mask);
 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
-				unsigned long index, gfp_t gfp_mask);
+				pgoff_t index, gfp_t gfp_mask);
 extern void remove_from_page_cache(struct page *page);
 extern void __remove_from_page_cache(struct page *page);