diff --git a/fs/aio.c b/fs/aio.c
index dbfcd67..670cb8b 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -45,6 +45,67 @@
 #define dprintk(x...)	do { ; } while (0)
 #endif
 
+#define AIO_RING_MAGIC			0xa10a10a1
+#define AIO_RING_COMPAT_FEATURES	1
+#define AIO_RING_INCOMPAT_FEATURES	0
+struct aio_ring {
+	unsigned	id;	/* kernel internal index number */
+	unsigned	nr;	/* number of io_events */
+	unsigned	head;
+	unsigned	tail;
+
+	unsigned	magic;
+	unsigned	compat_features;
+	unsigned	incompat_features;
+	unsigned	header_length;	/* size of aio_ring */
+
+
+	struct io_event		io_events[0];
+}; /* 128 bytes + ring size */
+
+#define AIO_RING_PAGES	8
+struct aio_ring_info {
+	unsigned long		mmap_base;
+	unsigned long		mmap_size;
+
+	struct page		**ring_pages;
+	spinlock_t		ring_lock;
+	long			nr_pages;
+
+	unsigned		nr, tail;
+
+	struct page		*internal_pages[AIO_RING_PAGES];
+};
+
+static inline unsigned aio_ring_avail(struct aio_ring_info *info,
+					struct aio_ring *ring)
+{
+	return (ring->head + info->nr - 1 - ring->tail) % info->nr;
+}
+
+struct kioctx {
+	atomic_t		users;
+	int			dead;
+
+	/* This needs improving */
+	unsigned long		user_id;
+	struct hlist_node	list;
+
+	wait_queue_head_t	wait;
+
+	spinlock_t		ctx_lock;
+
+	int			reqs_active;
+	struct list_head	active_reqs;	/* used for cancellation */
+
+	/* sys_io_setup currently limits this to an unsigned int */
+	unsigned		max_reqs;
+
+	struct aio_ring_info	ring_info;
+
+	struct rcu_head		rcu_head;
+};
+
 /*------ sysctl variables----*/
 static DEFINE_SPINLOCK(aio_nr_lock);
 unsigned long aio_nr;		/* current system wide number of aio requests */