ocfs2: Use filemap_write_and_wait_range() in ocfs2_cow_sync_writeback()

Remove the open-coding of filemap_fdatawait_range().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

fs/ocfs2/refcounttree.c

@@ -3146,48 +3146,18 @@ int ocfs2_cow_sync_writeback(struct super_block *sb,
 			     struct inode *inode,
 			     u32 cpos, u32 num_clusters)
 {
-	int ret = 0;
-	loff_t offset, end, map_end;
-	pgoff_t page_index;
-	struct page *page;
+	int ret;
+	loff_t start, end;
 
 	if (ocfs2_should_order_data(inode))
 		return 0;
 
-	offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
-	end = offset + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits);
-
-	ret = filemap_fdatawrite_range(inode->i_mapping,
-				       offset, end - 1);
-	if (ret < 0) {
-		mlog_errno(ret);
-		return ret;
-	}
-
-	while (offset < end) {
-		page_index = offset >> PAGE_SHIFT;
-		map_end = ((loff_t)page_index + 1) << PAGE_SHIFT;
-		if (map_end > end)
-			map_end = end;
-
-		page = find_or_create_page(inode->i_mapping,
-					   page_index, GFP_NOFS);
-		BUG_ON(!page);
+	start = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
+	end = start + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits) - 1;
 
-		wait_on_page_writeback(page);
-		if (PageError(page)) {
-			ret = -EIO;
+	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+	if (ret < 0)
 		mlog_errno(ret);
-		} else
-			mark_page_accessed(page);
-
-		unlock_page(page);
-		put_page(page);
-		page = NULL;
-		offset = map_end;
-		if (ret)
-			break;
-	}
 
 	return ret;
 }