Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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
13struct 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
46struct 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
99struct 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
117struct 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
130struct 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 */
155extern unsigned aio_max_size;
156
157extern ssize_t FASTCALL(wait_on_sync_kiocb(struct kiocb *iocb));
158extern int FASTCALL(aio_put_req(struct kiocb *iocb));
159extern void FASTCALL(kick_iocb(struct kiocb *iocb));
160extern int FASTCALL(aio_complete(struct kiocb *iocb, long res, long res2));
161extern void FASTCALL(__put_ioctx(struct kioctx *ctx));
162struct mm_struct;
163extern void FASTCALL(exit_aio(struct mm_struct *mm));
164extern struct kioctx *lookup_ioctx(unsigned long ctx_id);
165extern 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: */
169struct kioctx *lookup_ioctx(unsigned long ctx_id);
170int 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() \
179do { \
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
192static inline struct kiocb *list_kiocb(struct list_head *h)
193{
194 return list_entry(h, struct kiocb, ki_list);
195}
196
197/* for sysctl: */
198extern atomic_t aio_nr;
199extern unsigned aio_max_nr;
200
201#endif /* __LINUX__AIO_H */