1 files changed, 101 insertions, 6 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index c16fb6d06e36..0a97b583ee8d 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -259,12 +259,109 @@ pgoff_t page_cache_next_hole(struct address_space *mapping,
 pgoff_t page_cache_prev_hole(struct address_space *mapping,
                              pgoff_t index, unsigned long max_scan);
 
+#define FGP_ACCESSED            0x00000001
+#define FGP_LOCK                0x00000002
+#define FGP_CREAT               0x00000004
+#define FGP_WRITE               0x00000008
+#define FGP_NOFS                0x00000010
+#define FGP_NOWAIT              0x00000020
+
+struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
+                int fgp_flags, gfp_t cache_gfp_mask, gfp_t radix_gfp_mask);
+
+/**
+ * find_get_page - find and get a page reference
+ * @mapping: the address_space to search
+ * @offset: the page index
+ *
+ * Looks up the page cache slot at @mapping & @offset.  If there is a
+ * page cache page, it is returned with an increased refcount.
+ *
+ * Otherwise, %NULL is returned.
+ */
+static inline struct page *find_get_page(struct address_space *mapping,
+                                        pgoff_t offset)
+{
+        return pagecache_get_page(mapping, offset, 0, 0, 0);
+}
+
+static inline struct page *find_get_page_flags(struct address_space *mapping,
+                                        pgoff_t offset, int fgp_flags)
+{
+        return pagecache_get_page(mapping, offset, fgp_flags, 0, 0);
+}
+
+/**
+ * find_lock_page - locate, pin and lock a pagecache page
+ * pagecache_get_page - find and get a page reference
+ * @mapping: the address_space to search
+ * @offset: the page index
+ *
+ * Looks up the page cache slot at @mapping & @offset.  If there is a
+ * page cache page, it is returned locked and with an increased
+ * refcount.
+ *
+ * Otherwise, %NULL is returned.
+ *
+ * find_lock_page() may sleep.
+ */
+static inline struct page *find_lock_page(struct address_space *mapping,
+                                        pgoff_t offset)
+{
+        return pagecache_get_page(mapping, offset, FGP_LOCK, 0, 0);
+}
+
+/**
+ * find_or_create_page - locate or add a pagecache page
+ * @mapping: the page's address_space
+ * @index: the page's index into the mapping
+ * @gfp_mask: page allocation mode
+ *
+ * Looks up the page cache slot at @mapping & @offset.  If there is a
+ * page cache page, it is returned locked and with an increased
+ * refcount.
+ *
+ * If the page is not present, a new page is allocated using @gfp_mask
+ * and added to the page cache and the VM's LRU list.  The page is
+ * returned locked and with an increased refcount.
+ *
+ * On memory exhaustion, %NULL is returned.
+ *
+ * find_or_create_page() may sleep, even if @gfp_flags specifies an
+ * atomic allocation!
+ */
+static inline struct page *find_or_create_page(struct address_space *mapping,
+                                        pgoff_t offset, gfp_t gfp_mask)
+{
+        return pagecache_get_page(mapping, offset,
+                                        FGP_LOCK|FGP_ACCESSED|FGP_CREAT,
+                                        gfp_mask, gfp_mask & GFP_RECLAIM_MASK);
+}
+
+/**
+ * grab_cache_page_nowait - returns locked page at given index in given cache
+ * @mapping: target address_space
+ * @index: the page index
+ *
+ * Same as grab_cache_page(), but do not wait if the page is unavailable.
+ * This is intended for speculative data generators, where the data can
+ * be regenerated if the page couldn't be grabbed.  This routine should
+ * be safe to call while holding the lock for another page.
+ *
+ * Clear __GFP_FS when allocating the page to avoid recursion into the fs
+ * and deadlock against the caller's locked page.
+ */
+static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
+                                pgoff_t index)
+{
+        return pagecache_get_page(mapping, index,
+                        FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
+                        mapping_gfp_mask(mapping),
+                        GFP_NOFS);
+}
+
 struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
-struct page *find_get_page(struct address_space *mapping, pgoff_t offset);
 struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
-struct page *find_lock_page(struct address_space *mapping, pgoff_t offset);
-struct page *find_or_create_page(struct address_space *mapping, pgoff_t index,
-                                 gfp_t gfp_mask);
 unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
                           unsigned int nr_entries, struct page **entries,
                           pgoff_t *indices);
@@ -287,8 +384,6 @@ static inline struct page *grab_cache_page(struct address_space *mapping,
         return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
 }
 
-extern struct page * grab_cache_page_nowait(struct address_space *mapping,
-                                pgoff_t index);
 extern struct page * read_cache_page(struct address_space *mapping,
                                 pgoff_t index, filler_t *filler, void *data);
 extern struct page * read_cache_page_gfp(struct address_space *mapping,