diff --git a/include/linux/fs.h b/include/linux/fs.h
index 20fe15f..4a1cb00 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1639,6 +1639,7 @@
 			      struct iovec **ret_pointer);
 
 extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
+extern ssize_t __vfs_write(struct file *, const char __user *, size_t, loff_t *);
 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,