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-rw-r--r--fs/aio.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/fs/aio.c b/fs/aio.c
index dbfcd67003ef..670cb8b84345 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 */