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1da177e4 LT |
1 | #ifndef __LINUX__AIO_H |
2 | #define __LINUX__AIO_H | |
3 | ||
4 | #include <linux/list.h> | |
5 | #include <linux/workqueue.h> | |
6 | #include <linux/aio_abi.h> | |
7 | ||
8 | #include <asm/atomic.h> | |
9 | ||
10 | #define AIO_MAXSEGS 4 | |
11 | #define AIO_KIOGRP_NR_ATOMIC 8 | |
12 | ||
13 | struct kioctx; | |
14 | ||
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. | |
20 | */ | |
21 | #define KIOCB_C_CANCELLED 0x01 | |
22 | #define KIOCB_C_COMPLETE 0x02 | |
23 | ||
24 | #define KIOCB_SYNC_KEY (~0U) | |
25 | ||
26 | /* ki_flags bits */ | |
27 | #define KIF_LOCKED 0 | |
28 | #define KIF_KICKED 1 | |
29 | #define KIF_CANCELLED 2 | |
30 | ||
31 | #define kiocbTryLock(iocb) test_and_set_bit(KIF_LOCKED, &(iocb)->ki_flags) | |
32 | #define kiocbTryKick(iocb) test_and_set_bit(KIF_KICKED, &(iocb)->ki_flags) | |
33 | ||
34 | #define kiocbSetLocked(iocb) set_bit(KIF_LOCKED, &(iocb)->ki_flags) | |
35 | #define kiocbSetKicked(iocb) set_bit(KIF_KICKED, &(iocb)->ki_flags) | |
36 | #define kiocbSetCancelled(iocb) set_bit(KIF_CANCELLED, &(iocb)->ki_flags) | |
37 | ||
38 | #define kiocbClearLocked(iocb) clear_bit(KIF_LOCKED, &(iocb)->ki_flags) | |
39 | #define kiocbClearKicked(iocb) clear_bit(KIF_KICKED, &(iocb)->ki_flags) | |
40 | #define kiocbClearCancelled(iocb) clear_bit(KIF_CANCELLED, &(iocb)->ki_flags) | |
41 | ||
42 | #define kiocbIsLocked(iocb) test_bit(KIF_LOCKED, &(iocb)->ki_flags) | |
43 | #define kiocbIsKicked(iocb) test_bit(KIF_KICKED, &(iocb)->ki_flags) | |
44 | #define kiocbIsCancelled(iocb) test_bit(KIF_CANCELLED, &(iocb)->ki_flags) | |
45 | ||
46 | struct kiocb { | |
47 | struct list_head ki_run_list; | |
48 | long ki_flags; | |
49 | int ki_users; | |
50 | unsigned ki_key; /* id of this request */ | |
51 | ||
52 | struct file *ki_filp; | |
53 | struct kioctx *ki_ctx; /* may be NULL for sync ops */ | |
54 | int (*ki_cancel)(struct kiocb *, struct io_event *); | |
55 | ssize_t (*ki_retry)(struct kiocb *); | |
56 | void (*ki_dtor)(struct kiocb *); | |
57 | ||
58 | struct list_head ki_list; /* the aio core uses this | |
59 | * for cancellation */ | |
60 | ||
61 | union { | |
62 | void __user *user; | |
63 | struct task_struct *tsk; | |
64 | } ki_obj; | |
65 | __u64 ki_user_data; /* user's data for completion */ | |
66 | loff_t ki_pos; | |
67 | /* State that we remember to be able to restart/retry */ | |
68 | unsigned short ki_opcode; | |
69 | size_t ki_nbytes; /* copy of iocb->aio_nbytes */ | |
70 | char __user *ki_buf; /* remaining iocb->aio_buf */ | |
71 | size_t ki_left; /* remaining bytes */ | |
72 | wait_queue_t ki_wait; | |
73 | long ki_retried; /* just for testing */ | |
74 | long ki_kicked; /* just for testing */ | |
75 | long ki_queued; /* just for testing */ | |
76 | ||
77 | void *private; | |
78 | }; | |
79 | ||
80 | #define is_sync_kiocb(iocb) ((iocb)->ki_key == KIOCB_SYNC_KEY) | |
81 | #define init_sync_kiocb(x, filp) \ | |
82 | do { \ | |
83 | struct task_struct *tsk = current; \ | |
84 | (x)->ki_flags = 0; \ | |
85 | (x)->ki_users = 1; \ | |
86 | (x)->ki_key = KIOCB_SYNC_KEY; \ | |
87 | (x)->ki_filp = (filp); \ | |
88 | (x)->ki_ctx = &tsk->active_mm->default_kioctx; \ | |
89 | (x)->ki_cancel = NULL; \ | |
90 | (x)->ki_dtor = NULL; \ | |
91 | (x)->ki_obj.tsk = tsk; \ | |
92 | (x)->ki_user_data = 0; \ | |
93 | init_wait((&(x)->ki_wait)); \ | |
94 | } while (0) | |
95 | ||
96 | #define AIO_RING_MAGIC 0xa10a10a1 | |
97 | #define AIO_RING_COMPAT_FEATURES 1 | |
98 | #define AIO_RING_INCOMPAT_FEATURES 0 | |
99 | struct aio_ring { | |
100 | unsigned id; /* kernel internal index number */ | |
101 | unsigned nr; /* number of io_events */ | |
102 | unsigned head; | |
103 | unsigned tail; | |
104 | ||
105 | unsigned magic; | |
106 | unsigned compat_features; | |
107 | unsigned incompat_features; | |
108 | unsigned header_length; /* size of aio_ring */ | |
109 | ||
110 | ||
111 | struct io_event io_events[0]; | |
112 | }; /* 128 bytes + ring size */ | |
113 | ||
114 | #define aio_ring_avail(info, ring) (((ring)->head + (info)->nr - 1 - (ring)->tail) % (info)->nr) | |
115 | ||
116 | #define AIO_RING_PAGES 8 | |
117 | struct aio_ring_info { | |
118 | unsigned long mmap_base; | |
119 | unsigned long mmap_size; | |
120 | ||
121 | struct page **ring_pages; | |
122 | spinlock_t ring_lock; | |
123 | long nr_pages; | |
124 | ||
125 | unsigned nr, tail; | |
126 | ||
127 | struct page *internal_pages[AIO_RING_PAGES]; | |
128 | }; | |
129 | ||
130 | struct kioctx { | |
131 | atomic_t users; | |
132 | int dead; | |
133 | struct mm_struct *mm; | |
134 | ||
135 | /* This needs improving */ | |
136 | unsigned long user_id; | |
137 | struct kioctx *next; | |
138 | ||
139 | wait_queue_head_t wait; | |
140 | ||
141 | spinlock_t ctx_lock; | |
142 | ||
143 | int reqs_active; | |
144 | struct list_head active_reqs; /* used for cancellation */ | |
145 | struct list_head run_list; /* used for kicked reqs */ | |
146 | ||
147 | unsigned max_reqs; | |
148 | ||
149 | struct aio_ring_info ring_info; | |
150 | ||
151 | struct work_struct wq; | |
152 | }; | |
153 | ||
154 | /* prototypes */ | |
155 | extern unsigned aio_max_size; | |
156 | ||
157 | extern ssize_t FASTCALL(wait_on_sync_kiocb(struct kiocb *iocb)); | |
158 | extern int FASTCALL(aio_put_req(struct kiocb *iocb)); | |
159 | extern void FASTCALL(kick_iocb(struct kiocb *iocb)); | |
160 | extern int FASTCALL(aio_complete(struct kiocb *iocb, long res, long res2)); | |
161 | extern void FASTCALL(__put_ioctx(struct kioctx *ctx)); | |
162 | struct mm_struct; | |
163 | extern void FASTCALL(exit_aio(struct mm_struct *mm)); | |
164 | extern struct kioctx *lookup_ioctx(unsigned long ctx_id); | |
165 | extern int FASTCALL(io_submit_one(struct kioctx *ctx, | |
166 | struct iocb __user *user_iocb, struct iocb *iocb)); | |
167 | ||
168 | /* semi private, but used by the 32bit emulations: */ | |
169 | struct kioctx *lookup_ioctx(unsigned long ctx_id); | |
170 | int FASTCALL(io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, | |
171 | struct iocb *iocb)); | |
172 | ||
173 | #define get_ioctx(kioctx) do { if (unlikely(atomic_read(&(kioctx)->users) <= 0)) BUG(); atomic_inc(&(kioctx)->users); } while (0) | |
174 | #define put_ioctx(kioctx) do { if (unlikely(atomic_dec_and_test(&(kioctx)->users))) __put_ioctx(kioctx); else if (unlikely(atomic_read(&(kioctx)->users) < 0)) BUG(); } while (0) | |
175 | ||
176 | #define in_aio() !is_sync_wait(current->io_wait) | |
177 | /* may be used for debugging */ | |
178 | #define warn_if_async() \ | |
179 | do { \ | |
180 | if (in_aio()) { \ | |
181 | printk(KERN_ERR "%s(%s:%d) called in async context!\n", \ | |
182 | __FUNCTION__, __FILE__, __LINE__); \ | |
183 | dump_stack(); \ | |
184 | } \ | |
185 | } while (0) | |
186 | ||
187 | #define io_wait_to_kiocb(wait) container_of(wait, struct kiocb, ki_wait) | |
188 | #define is_retried_kiocb(iocb) ((iocb)->ki_retried > 1) | |
189 | ||
190 | #include <linux/aio_abi.h> | |
191 | ||
192 | static inline struct kiocb *list_kiocb(struct list_head *h) | |
193 | { | |
194 | return list_entry(h, struct kiocb, ki_list); | |
195 | } | |
196 | ||
197 | /* for sysctl: */ | |
198 | extern atomic_t aio_nr; | |
199 | extern unsigned aio_max_nr; | |
200 | ||
201 | #endif /* __LINUX__AIO_H */ |