diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9dfd7c7..87be51a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -48,6 +48,7 @@
 struct swap_info_struct;
 struct seq_file;
 struct workqueue_struct;
+struct iov_iter;
 
 extern void __init inode_init(void);
 extern void __init inode_init_early(void);
@@ -2396,6 +2397,7 @@
 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
 		unsigned long *, loff_t, size_t, size_t);
+extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
 extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
 		unsigned long, loff_t, size_t, ssize_t);
 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);