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 #include <linux/uio.h> 8 #include <linux/rcupdate.h> 9 10 #include <linux/atomic.h> 11 12 struct kioctx; 13 struct kiocb; 14 15 #define KIOCB_KEY 0 16 17 /* 18 * We use ki_cancel == KIOCB_CANCELLED to indicate that a kiocb has been either 19 * cancelled or completed (this makes a certain amount of sense because 20 * successful cancellation - io_cancel() - does deliver the completion to 21 * userspace). 22 * 23 * And since most things don't implement kiocb cancellation and we'd really like 24 * kiocb completion to be lockless when possible, we use ki_cancel to 25 * synchronize cancellation and completion - we only set it to KIOCB_CANCELLED 26 * with xchg() or cmpxchg(), see batch_complete_aio() and kiocb_cancel(). 27 */ 28 #define KIOCB_CANCELLED ((void *) (~0ULL)) 29 30 typedef int (kiocb_cancel_fn)(struct kiocb *, struct io_event *); 31 32 struct kiocb { 33 atomic_t ki_users; 34 35 struct file *ki_filp; 36 struct kioctx *ki_ctx; /* NULL for sync ops */ 37 kiocb_cancel_fn *ki_cancel; 38 void (*ki_dtor)(struct kiocb *); 39 40 union { 41 void __user *user; 42 struct task_struct *tsk; 43 } ki_obj; 44 45 __u64 ki_user_data; /* user's data for completion */ 46 loff_t ki_pos; 47 48 void *private; 49 /* State that we remember to be able to restart/retry */ 50 unsigned short ki_opcode; 51 size_t ki_nbytes; /* copy of iocb->aio_nbytes */ 52 char __user *ki_buf; /* remaining iocb->aio_buf */ 53 size_t ki_left; /* remaining bytes */ 54 struct iovec ki_inline_vec; /* inline vector */ 55 struct iovec *ki_iovec; 56 unsigned long ki_nr_segs; 57 unsigned long ki_cur_seg; 58 59 struct list_head ki_list; /* the aio core uses this 60 * for cancellation */ 61 62 /* 63 * If the aio_resfd field of the userspace iocb is not zero, 64 * this is the underlying eventfd context to deliver events to. 65 */ 66 struct eventfd_ctx *ki_eventfd; 67 }; 68 69 static inline bool is_sync_kiocb(struct kiocb *kiocb) 70 { 71 return kiocb->ki_ctx == NULL; 72 } 73 74 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) 75 { 76 *kiocb = (struct kiocb) { 77 .ki_users = ATOMIC_INIT(1), 78 .ki_ctx = NULL, 79 .ki_filp = filp, 80 .ki_obj.tsk = current, 81 }; 82 } 83 84 /* prototypes */ 85 #ifdef CONFIG_AIO 86 extern ssize_t wait_on_sync_kiocb(struct kiocb *iocb); 87 extern void aio_put_req(struct kiocb *iocb); 88 extern void aio_complete(struct kiocb *iocb, long res, long res2); 89 struct mm_struct; 90 extern void exit_aio(struct mm_struct *mm); 91 extern long do_io_submit(aio_context_t ctx_id, long nr, 92 struct iocb __user *__user *iocbpp, bool compat); 93 void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel); 94 #else 95 static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; } 96 static inline void aio_put_req(struct kiocb *iocb) { } 97 static inline void aio_complete(struct kiocb *iocb, long res, long res2) { } 98 struct mm_struct; 99 static inline void exit_aio(struct mm_struct *mm) { } 100 static inline long do_io_submit(aio_context_t ctx_id, long nr, 101 struct iocb __user * __user *iocbpp, 102 bool compat) { return 0; } 103 static inline void kiocb_set_cancel_fn(struct kiocb *req, 104 kiocb_cancel_fn *cancel) { } 105 #endif /* CONFIG_AIO */ 106 107 static inline struct kiocb *list_kiocb(struct list_head *h) 108 { 109 return list_entry(h, struct kiocb, ki_list); 110 } 111 112 /* for sysctl: */ 113 extern unsigned long aio_nr; 114 extern unsigned long aio_max_nr; 115 116 #endif /* __LINUX__AIO_H */ 117