diff options
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 61 |
1 files changed, 61 insertions, 0 deletions
@@ -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 */ |