diff --git a/fs/9p/trans_fd.c b/fs/9p/trans_fd.c
index 1a28ef9..5b2ce21 100644
--- a/fs/9p/trans_fd.c
+++ b/fs/9p/trans_fd.c
@@ -80,6 +80,7 @@
 	if (!trans || trans->status != Connected || !ts)
 		return -EIO;
 
+	oldfs = get_fs();
 	set_fs(get_ds());
 	/* The cast to a user pointer is valid due to the set_fs() */
 	ret = vfs_write(ts->out_file, (void __user *)v, len, &ts->out_file->f_pos);