1 files changed, 23 insertions, 13 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 8a83537d6978..db8a410ae9e1 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -84,11 +84,11 @@ static inline struct page *page_cache_alloc_cold(struct address_space *x)
 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,
@@ -96,44 +96,47 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
 unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
                         int tag, unsigned int nr_pages, struct page **pages);
 
+struct page *__grab_cache_page(struct address_space *mapping, pgoff_t index);
+
 /*
  * 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);
 
@@ -218,6 +221,9 @@ static inline int fault_in_pages_writeable(char __user *uaddr, int size)
 {
         int ret;
 
+        if (unlikely(size == 0))
+                return 0;
+
         /*
          * Writing zeroes into userspace here is OK, because we know that if
          * the zero gets there, we'll be overwriting it.
@@ -237,19 +243,23 @@ static inline int fault_in_pages_writeable(char __user *uaddr, int size)
         return ret;
 }
 
-static inline void fault_in_pages_readable(const char __user *uaddr, int size)
+static inline int fault_in_pages_readable(const char __user *uaddr, int size)
 {
         volatile char c;
         int ret;
 
+        if (unlikely(size == 0))
+                return 0;
+
         ret = __get_user(c, uaddr);
         if (ret == 0) {
                 const char __user *end = uaddr + size - 1;
 
                 if (((unsigned long)uaddr & PAGE_MASK) !=
                                 ((unsigned long)end & PAGE_MASK))
-                        __get_user(c, end);
+                        ret = __get_user(c, end);
         }
+        return ret;
 }
 
 #endif /* _LINUX_PAGEMAP_H */