diff --git a/include/l4/api/thread.h b/include/l4/api/thread.h
index f622c26..4d2761c 100644
--- a/include/l4/api/thread.h
+++ b/include/l4/api/thread.h
@@ -20,5 +20,6 @@
 #define THREAD_RUN			0x0001
 #define THREAD_SUSPEND			0x0002
 #define THREAD_RESUME			0x0003
+#define THREAD_DESTROY			0x0004
 
 #endif /* __THREAD_H__ */
diff --git a/src/lib/wait.c b/src/lib/wait.c
index e76c817..6e52ece 100644
--- a/src/lib/wait.c
+++ b/src/lib/wait.c
@@ -37,6 +37,7 @@ do {							\
 	spin_unlock(&wqh->slock);			\
 } while(0);
 
+/* FIXME: Wake up should take the task as an argument, rather than the queue */
 /* Wake up single waiter */
 void wake_up(struct waitqueue_head *wqh)
 {
diff --git a/tasks/fs0/src/task.c b/tasks/fs0/src/task.c
index 291cd7d..ca3f9fb 100644
--- a/tasks/fs0/src/task.c
+++ b/tasks/fs0/src/task.c
@@ -151,7 +151,7 @@ int pager_notify_fork(struct tcb *sender, l4id_t parid,
 	id_pool_copy(child->fdpool, parent->fdpool, TASK_FILES_MAX);
 	memcpy(child->fd, parent->fd, TASK_FILES_MAX * sizeof(int));
 
-	printf("%s/%s: Exiting...\n", __TASKNAME__, __FUNCTION__);
+	// printf("%s/%s: Exiting...\n", __TASKNAME__, __FUNCTION__);
 	return 0;
 }
 
diff --git a/tasks/libl4/include/l4lib/ipcdefs.h b/tasks/libl4/include/l4lib/ipcdefs.h
index ec3c725..07ea035 100644
--- a/tasks/libl4/include/l4lib/ipcdefs.h
+++ b/tasks/libl4/include/l4lib/ipcdefs.h
@@ -59,5 +59,6 @@
 #define L4_IPC_TAG_PAGER_CLOSE		44	/* Pager notifies vfs of file close */
 #define L4_IPC_TAG_PAGER_UPDATE_STATS	45	/* Pager updates file stats in vfs */
 #define L4_IPC_TAG_NOTIFY_FORK		46	/* Pager notifies vfs of process fork */
+#define L4_IPC_TAG_NOTIFY_EXIT		46	/* Pager notifies vfs of process exit */
 
 #endif /* __IPCDEFS_H__ */
diff --git a/tasks/mm0/include/syscalls.h b/tasks/mm0/include/syscalls.h
index 2f8bb02..6d17e06 100644
--- a/tasks/mm0/include/syscalls.h
+++ b/tasks/mm0/include/syscalls.h
@@ -46,6 +46,7 @@ struct sys_shmget_args {
 int sys_shmget(key_t key, int size, int shmflg);
 
 int sys_fork(struct tcb *parent);
+void sys_exit(struct tcb *task, int status);
 
 #endif /* __MM0_SYSARGS_H__ */
 
diff --git a/tasks/mm0/include/utcb.h b/tasks/mm0/include/utcb.h
index 6e22eda..fb33e1b 100644
--- a/tasks/mm0/include/utcb.h
+++ b/tasks/mm0/include/utcb.h
@@ -5,6 +5,7 @@
 #include <task.h>
 void *utcb_vaddr_new(void);
 int utcb_pool_init(void);
+int utcb_vaddr_del(void *utcb_addr);
 
 
 /* IPC to send utcb address information to tasks */
diff --git a/tasks/mm0/src/clone.c b/tasks/mm0/src/clone.c
index 7802cb7..5c54e53 100755
--- a/tasks/mm0/src/clone.c
+++ b/tasks/mm0/src/clone.c
@@ -105,7 +105,6 @@ int sys_fork(struct tcb *parent)
 	task_add_global(child);
 
 	/* Start forked child. */
-	printf("%s/%s: Starting forked child.\n", __TASKNAME__, __FUNCTION__);
 	l4_thread_control(THREAD_RUN, &ids);
 
 	/* Return child tid to parent */
diff --git a/tasks/mm0/src/file.c b/tasks/mm0/src/file.c
index 5eac94d..8fe63bf 100644
--- a/tasks/mm0/src/file.c
+++ b/tasks/mm0/src/file.c
@@ -371,13 +371,19 @@ int fsync_common(struct tcb *task, int fd)
 	int err;
 
 	/* Check fd validity */
+	if (fd < 0 || fd > TASK_FILES_MAX)
+		return -EINVAL;
+
+	/*
+	 * If we don't know about the file, even if it was
+	 * opened by the vfs, it is sure that there's no
+	 * pending IO on it. We simply return.
+	 */
 	if (!task->files->fd[fd].vmfile)
-		if ((err = file_open(task, fd)) < 0)
-			return err;
+		return 0;
 
 	/* Finish I/O on file */
-	BUG_ON(!(f = task->files->fd[fd].vmfile));
-	if ((err = flush_file_pages(f)) < 0)
+	if ((err = flush_file_pages(task->files->fd[fd].vmfile)) < 0)
 		return err;
 
 	return 0;
diff --git a/tasks/mm0/src/utcb.c b/tasks/mm0/src/utcb.c
index 39225d2..d201e54 100644
--- a/tasks/mm0/src/utcb.c
+++ b/tasks/mm0/src/utcb.c
@@ -33,6 +33,11 @@ void *utcb_vaddr_new(void)
 	return address_new(&utcb_vaddr_pool, 1);
 }
 
+int utcb_vaddr_del(void *utcb_addr)
+{
+	return address_del(&utcb_vaddr_pool, utcb_addr, 1);
+}
+
 /*
  * Sends utcb address information to requester task, allocates
  * an address if it doesn't exist and the requester is asking