vfs: pagecache usage optimization for pagesize!=blocksize

[safe/jmp/linux-2.6] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8252b04..580b513 100644 (file)
--- 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. */