4 #include <linux/list.h>
5 #include <linux/workqueue.h>
6 #include <linux/aio_abi.h>
8 #include <asm/atomic.h>
11 #define AIO_KIOGRP_NR_ATOMIC 8
15 /* Notes on cancelling a kiocb:
16 * If a kiocb is cancelled, aio_complete may return 0 to indicate
17 * that cancel has not yet disposed of the kiocb. All cancel
18 * operations *must* call aio_put_req to dispose of the kiocb
19 * to guard against races with the completion code.
21 #define KIOCB_C_CANCELLED 0x01
22 #define KIOCB_C_COMPLETE 0x02
24 #define KIOCB_SYNC_KEY (~0U)
28 * This may be used for cancel/retry serialization in the future, but
29 * for now it's unused and we probably don't want modules to even
30 * think they can use it.
32 /* #define KIF_LOCKED 0 */
34 #define KIF_CANCELLED 2
36 #define kiocbTryLock(iocb) test_and_set_bit(KIF_LOCKED, &(iocb)->ki_flags)
37 #define kiocbTryKick(iocb) test_and_set_bit(KIF_KICKED, &(iocb)->ki_flags)
39 #define kiocbSetLocked(iocb) set_bit(KIF_LOCKED, &(iocb)->ki_flags)
40 #define kiocbSetKicked(iocb) set_bit(KIF_KICKED, &(iocb)->ki_flags)
41 #define kiocbSetCancelled(iocb) set_bit(KIF_CANCELLED, &(iocb)->ki_flags)
43 #define kiocbClearLocked(iocb) clear_bit(KIF_LOCKED, &(iocb)->ki_flags)
44 #define kiocbClearKicked(iocb) clear_bit(KIF_KICKED, &(iocb)->ki_flags)
45 #define kiocbClearCancelled(iocb) clear_bit(KIF_CANCELLED, &(iocb)->ki_flags)
47 #define kiocbIsLocked(iocb) test_bit(KIF_LOCKED, &(iocb)->ki_flags)
48 #define kiocbIsKicked(iocb) test_bit(KIF_KICKED, &(iocb)->ki_flags)
49 #define kiocbIsCancelled(iocb) test_bit(KIF_CANCELLED, &(iocb)->ki_flags)
51 /* is there a better place to document function pointer methods? */
53 * ki_retry - iocb forward progress callback
54 * @kiocb: The kiocb struct to advance by performing an operation.
56 * This callback is called when the AIO core wants a given AIO operation
57 * to make forward progress. The kiocb argument describes the operation
58 * that is to be performed. As the operation proceeds, perhaps partially,
59 * ki_retry is expected to update the kiocb with progress made. Typically
60 * ki_retry is set in the AIO core and it itself calls file_operations
63 * ki_retry's return value determines when the AIO operation is completed
64 * and an event is generated in the AIO event ring. Except the special
65 * return values described below, the value that is returned from ki_retry
66 * is transferred directly into the completion ring as the operation's
67 * resulting status. Once this has happened ki_retry *MUST NOT* reference
68 * the kiocb pointer again.
70 * If ki_retry returns -EIOCBQUEUED it has made a promise that aio_complete()
71 * will be called on the kiocb pointer in the future. The AIO core will
72 * not ask the method again -- ki_retry must ensure forward progress.
73 * aio_complete() must be called once and only once in the future, multiple
74 * calls may result in undefined behaviour.
76 * If ki_retry returns -EIOCBRETRY it has made a promise that kick_iocb()
77 * will be called on the kiocb pointer in the future. This may happen
78 * through generic helpers that associate kiocb->ki_wait with a wait
79 * queue head that ki_retry uses via current->io_wait. It can also happen
80 * with custom tracking and manual calls to kick_iocb(), though that is
81 * discouraged. In either case, kick_iocb() must be called once and only
82 * once. ki_retry must ensure forward progress, the AIO core will wait
83 * indefinitely for kick_iocb() to be called.
86 struct list_head ki_run_list;
89 unsigned ki_key; /* id of this request */
92 struct kioctx *ki_ctx; /* may be NULL for sync ops */
93 int (*ki_cancel)(struct kiocb *, struct io_event *);
94 ssize_t (*ki_retry)(struct kiocb *);
95 void (*ki_dtor)(struct kiocb *);
99 struct task_struct *tsk;
102 __u64 ki_user_data; /* user's data for completion */
103 wait_queue_t ki_wait;
107 /* State that we remember to be able to restart/retry */
108 unsigned short ki_opcode;
109 size_t ki_nbytes; /* copy of iocb->aio_nbytes */
110 char __user *ki_buf; /* remaining iocb->aio_buf */
111 size_t ki_left; /* remaining bytes */
112 long ki_retried; /* just for testing */
113 long ki_kicked; /* just for testing */
114 long ki_queued; /* just for testing */
116 struct list_head ki_list; /* the aio core uses this
117 * for cancellation */
120 #define is_sync_kiocb(iocb) ((iocb)->ki_key == KIOCB_SYNC_KEY)
121 #define init_sync_kiocb(x, filp) \
123 struct task_struct *tsk = current; \
126 (x)->ki_key = KIOCB_SYNC_KEY; \
127 (x)->ki_filp = (filp); \
128 (x)->ki_ctx = NULL; \
129 (x)->ki_cancel = NULL; \
130 (x)->ki_retry = NULL; \
131 (x)->ki_dtor = NULL; \
132 (x)->ki_obj.tsk = tsk; \
133 (x)->ki_user_data = 0; \
134 init_wait((&(x)->ki_wait)); \
137 #define AIO_RING_MAGIC 0xa10a10a1
138 #define AIO_RING_COMPAT_FEATURES 1
139 #define AIO_RING_INCOMPAT_FEATURES 0
141 unsigned id; /* kernel internal index number */
142 unsigned nr; /* number of io_events */
147 unsigned compat_features;
148 unsigned incompat_features;
149 unsigned header_length; /* size of aio_ring */
152 struct io_event io_events[0];
153 }; /* 128 bytes + ring size */
155 #define aio_ring_avail(info, ring) (((ring)->head + (info)->nr - 1 - (ring)->tail) % (info)->nr)
157 #define AIO_RING_PAGES 8
158 struct aio_ring_info {
159 unsigned long mmap_base;
160 unsigned long mmap_size;
162 struct page **ring_pages;
163 spinlock_t ring_lock;
168 struct page *internal_pages[AIO_RING_PAGES];
174 struct mm_struct *mm;
176 /* This needs improving */
177 unsigned long user_id;
180 wait_queue_head_t wait;
185 struct list_head active_reqs; /* used for cancellation */
186 struct list_head run_list; /* used for kicked reqs */
188 /* sys_io_setup currently limits this to an unsigned int */
191 struct aio_ring_info ring_info;
193 struct work_struct wq;
197 extern unsigned aio_max_size;
199 extern ssize_t FASTCALL(wait_on_sync_kiocb(struct kiocb *iocb));
200 extern int FASTCALL(aio_put_req(struct kiocb *iocb));
201 extern void FASTCALL(kick_iocb(struct kiocb *iocb));
202 extern int FASTCALL(aio_complete(struct kiocb *iocb, long res, long res2));
203 extern void FASTCALL(__put_ioctx(struct kioctx *ctx));
205 extern void FASTCALL(exit_aio(struct mm_struct *mm));
206 extern struct kioctx *lookup_ioctx(unsigned long ctx_id);
207 extern int FASTCALL(io_submit_one(struct kioctx *ctx,
208 struct iocb __user *user_iocb, struct iocb *iocb));
210 /* semi private, but used by the 32bit emulations: */
211 struct kioctx *lookup_ioctx(unsigned long ctx_id);
212 int FASTCALL(io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
215 #define get_ioctx(kioctx) do { \
216 BUG_ON(atomic_read(&(kioctx)->users) <= 0); \
217 atomic_inc(&(kioctx)->users); \
219 #define put_ioctx(kioctx) do { \
220 BUG_ON(atomic_read(&(kioctx)->users) <= 0); \
221 if (unlikely(atomic_dec_and_test(&(kioctx)->users))) \
222 __put_ioctx(kioctx); \
225 #define in_aio() !is_sync_wait(current->io_wait)
226 /* may be used for debugging */
227 #define warn_if_async() \
230 printk(KERN_ERR "%s(%s:%d) called in async context!\n", \
231 __FUNCTION__, __FILE__, __LINE__); \
236 #define io_wait_to_kiocb(wait) container_of(wait, struct kiocb, ki_wait)
237 #define is_retried_kiocb(iocb) ((iocb)->ki_retried > 1)
239 #include <linux/aio_abi.h>
241 static inline struct kiocb *list_kiocb(struct list_head *h)
243 return list_entry(h, struct kiocb, ki_list);
247 extern unsigned long aio_nr;
248 extern unsigned long aio_max_nr;
250 #endif /* __LINUX__AIO_H */