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 */ 202