2 files changed, 25 insertions, 21 deletions

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 82aa36c53ea7..50cfe8ceb478 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -205,6 +205,8 @@ void block_invalidatepage(struct page *page, unsigned long offset);
 int block_write_full_page(struct page *page, get_block_t *get_block,
                                 struct writeback_control *wbc);
 int block_read_full_page(struct page*, get_block_t*);
+int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
+                                unsigned long from);
 int block_write_begin(struct file *, struct address_space *,
                                 loff_t, unsigned, unsigned,
                                 struct page **, void **, get_block_t*);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8252b045e624..580b513668fe 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -443,6 +443,27 @@ static inline size_t iov_iter_count(struct iov_iter *i)
         return i->count;
 }
 
+/*
+ * "descriptor" for what we're up to with a read.
+ * This allows us to use the same read code yet
+ * have multiple different users of the data that
+ * we read from a file.
+ *
+ * The simplest case just copies the data to user
+ * mode.
+ */
+typedef struct {
+        size_t written;
+        size_t count;
+        union {
+                char __user *buf;
+                void *data;
+        } arg;
+        int error;
+} read_descriptor_t;
+
+typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
+                unsigned long, unsigned long);
 
 struct address_space_operations {
         int (*writepage)(struct page *page, struct writeback_control *wbc);
@@ -484,6 +505,8 @@ struct address_space_operations {
         int (*migratepage) (struct address_space *,
                         struct page *, struct page *);
         int (*launder_page) (struct page *);
+        int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
+                                        unsigned long);
 };
 
 /*
@@ -1198,27 +1221,6 @@ struct block_device_operations {
         struct module *owner;
 };
 
-/*
- * "descriptor" for what we're up to with a read.
- * This allows us to use the same read code yet
- * have multiple different users of the data that
- * we read from a file.
- *
- * The simplest case just copies the data to user
- * mode.
- */
-typedef struct {
-        size_t written;
-        size_t count;
-        union {
-                char __user * buf;
-                void *data;
-        } arg;
-        int error;
-} read_descriptor_t;
-
-typedef int (*read_actor_t)(read_descriptor_t *, struct page *, unsigned long, unsigned long);
-
 /* These macros are for out of kernel modules to test that
  * the kernel supports the unlocked_ioctl and compat_ioctl
  * fields in struct file_operations. */