ocfs2: pass struct file* to ocfs2_write_begin_nolock.

struct file * has file_ra_state to store the readahead state
and data. So pass this to ocfs2_write_begin_nolock so that
it can be used in ocfs2_refcount_cow.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
index af2b8fe..b04d696 100644
--- a/fs/ocfs2/mmap.c
+++ b/fs/ocfs2/mmap.c
@@ -59,10 +59,11 @@
 	return ret;
 }
 
-static int __ocfs2_page_mkwrite(struct inode *inode, struct buffer_head *di_bh,
+static int __ocfs2_page_mkwrite(struct file *file, struct buffer_head *di_bh,
 				struct page *page)
 {
 	int ret;
+	struct inode *inode = file->f_path.dentry->d_inode;
 	struct address_space *mapping = inode->i_mapping;
 	loff_t pos = page_offset(page);
 	unsigned int len = PAGE_CACHE_SIZE;
@@ -109,7 +110,7 @@
 	if (page->index == last_index)
 		len = size & ~PAGE_CACHE_MASK;
 
-	ret = ocfs2_write_begin_nolock(mapping, pos, len, 0, &locked_page,
+	ret = ocfs2_write_begin_nolock(file, mapping, pos, len, 0, &locked_page,
 				       &fsdata, di_bh, page);
 	if (ret) {
 		if (ret != -ENOSPC)
@@ -157,7 +158,7 @@
 	 */
 	down_write(&OCFS2_I(inode)->ip_alloc_sem);
 
-	ret = __ocfs2_page_mkwrite(inode, di_bh, page);
+	ret = __ocfs2_page_mkwrite(vma->vm_file, di_bh, page);
 
 	up_write(&OCFS2_I(inode)->ip_alloc_sem);