Index: uspace/srv/vfs/vfs_ops.c
===================================================================
--- uspace/srv/vfs/vfs_ops.c	(revision 84adbf0de4924a0d5eb7352c86b917f907efae6f)
+++ uspace/srv/vfs/vfs_ops.c	(revision 4bda76b0323cdcbbaaba7347e616c3fee0315043)
@@ -487,6 +487,9 @@
 void vfs_open(ipc_callid_t rid, ipc_call_t *request)
 {
+	async_serialize_start();
+	
 	if (!vfs_files_init()) {
 		ipc_answer_0(rid, ENOMEM);
+		async_serialize_end();
 		return;
 	}
@@ -512,4 +515,5 @@
 	    (lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) {
 		ipc_answer_0(rid, EINVAL);
+		async_serialize_end();
 		return;
 	}
@@ -525,4 +529,5 @@
 		ipc_answer_0(callid, EINVAL);
 		ipc_answer_0(rid, EINVAL);
+		async_serialize_end();
 		return;
 	}
@@ -531,4 +536,5 @@
 		ipc_answer_0(callid, ENOMEM);
 		ipc_answer_0(rid, ENOMEM);
+		async_serialize_end();
 		return;
 	}
@@ -537,4 +543,5 @@
 		ipc_answer_0(rid, rc);
 		free(path);
+		async_serialize_end();
 		return;
 	}
@@ -561,4 +568,5 @@
 		ipc_answer_0(rid, rc);
 		free(path);
+		async_serialize_end();
 		return;
 	}
@@ -583,4 +591,5 @@
 				vfs_node_put(node);
 				ipc_answer_0(rid, rc);
+				async_serialize_end();
 				return;
 			}
@@ -598,4 +607,5 @@
 		vfs_node_put(node);
 		ipc_answer_0(rid, fd);
+		async_serialize_end();
 		return;
 	}
@@ -617,4 +627,5 @@
 	/* Success! Return the new file descriptor to the client. */
 	ipc_answer_1(rid, EOK, fd);
+	async_serialize_end();
 }