switch ->is_partially_uptodate() to saner arguments

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Documentation/filesystems/Locking

@@ -198,7 +198,7 @@ prototypes:
 				unsigned long *);
 	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);
+	int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long);
 	int (*error_remove_page)(struct address_space *, struct page *);
 	int (*swap_activate)(struct file *);
 	int (*swap_deactivate)(struct file *);

Documentation/filesystems/vfs.txt

@@ -580,7 +580,7 @@ struct address_space_operations {
 	/* migrate the contents of a page to the specified target */
 	int (*migratepage) (struct page *, struct page *);
 	int (*launder_page) (struct page *);
-	int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
+	int (*is_partially_uptodate) (struct page *, unsigned long,
 					unsigned long);
 	void (*is_dirty_writeback) (struct page *, bool *, bool *);
 	int (*error_remove_page) (struct mapping *mapping, struct page *page);

fs/buffer.c

@@ -2114,8 +2114,8 @@ EXPORT_SYMBOL(generic_write_end);
  * Returns true if all buffers which correspond to a file portion
  * we want to read are uptodate.
  */
-int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
-					unsigned long from)
+int block_is_partially_uptodate(struct page *page, unsigned long from,
+					unsigned long count)
 {
 	unsigned block_start, block_end, blocksize;
 	unsigned to;
@@ -2127,7 +2127,7 @@ int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
 
 	head = page_buffers(page);
 	blocksize = head->b_size;
-	to = min_t(unsigned, PAGE_CACHE_SIZE - from, desc->count);
+	to = min_t(unsigned, PAGE_CACHE_SIZE - from, count);
 	to = from + to;
 	if (from < blocksize && to > PAGE_CACHE_SIZE - blocksize)
 		return 0;

include/linux/buffer_head.h

@@ -210,8 +210,8 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
 int block_write_full_page_endio(struct page *page, get_block_t *get_block,
 			struct writeback_control *wbc, bh_end_io_t *handler);
 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_is_partially_uptodate(struct page *page, unsigned long from,
+				unsigned long count);
 int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
 		unsigned flags, struct page **pagep, get_block_t *get_block);
 int __block_write_begin(struct page *page, loff_t pos, unsigned len,

include/linux/fs.h

@@ -385,7 +385,7 @@ struct address_space_operations {
 	int (*migratepage) (struct address_space *,
 			struct page *, struct page *, enum migrate_mode);
 	int (*launder_page) (struct page *);
-	int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
+	int (*is_partially_uptodate) (struct page *, unsigned long,
 					unsigned long);
 	void (*is_dirty_writeback) (struct page *, bool *, bool *);
 	int (*error_remove_page)(struct address_space *, struct page *);

mm/filemap.c

@@ -1148,7 +1148,7 @@ static void do_generic_file_read(struct file *filp, loff_t *ppos,
 			if (!page->mapping)
 				goto page_not_up_to_date_locked;
 			if (!mapping->a_ops->is_partially_uptodate(page,
-								desc, offset))
+							offset, desc->count))
 				goto page_not_up_to_date_locked;
 			unlock_page(page);
 		}