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 *); 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 void *private; 40 41 union { 42 void __user *user; 43 struct task_struct *tsk; 44 } ki_obj; 45 46 __u64 ki_user_data; /* user's data for completion */ 47 loff_t ki_pos; 48 size_t ki_nbytes; /* copy of iocb->aio_nbytes */ 49 50 struct list_head ki_list; /* the aio core uses this 51 * for cancellation */ 52 53 /* 54 * If the aio_resfd field of the userspace iocb is not zero, 55 * this is the underlying eventfd context to deliver events to. 56 */ 57 struct eventfd_ctx *ki_eventfd; 58 }; 59 60 static inline bool is_sync_kiocb(struct kiocb *kiocb) 61 { 62 return kiocb->ki_ctx == NULL; 63 } 64 65 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) 66 { 67 *kiocb = (struct kiocb) { 68 .ki_users = ATOMIC_INIT(1), 69 .ki_ctx = NULL, 70 .ki_filp = filp, 71 .ki_obj.tsk = current, 72 }; 73 } 74 75 /* prototypes */ 76 #ifdef CONFIG_AIO 77 extern ssize_t wait_on_sync_kiocb(struct kiocb *iocb); 78 extern void aio_put_req(struct kiocb *iocb); 79 extern void aio_complete(struct kiocb *iocb, long res, long res2); 80 struct mm_struct; 81 extern void exit_aio(struct mm_struct *mm); 82 extern long do_io_submit(aio_context_t ctx_id, long nr, 83 struct iocb __user *__user *iocbpp, bool compat); 84 void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel); 85 #else 86 static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; } 87 static inline void aio_put_req(struct kiocb *iocb) { } 88 static inline void aio_complete(struct kiocb *iocb, long res, long res2) { } 89 struct mm_struct; 90 static inline void exit_aio(struct mm_struct *mm) { } 91 static inline long do_io_submit(aio_context_t ctx_id, long nr, 92 struct iocb __user * __user *iocbpp, 93 bool compat) { return 0; } 94 static inline void kiocb_set_cancel_fn(struct kiocb *req, 95 kiocb_cancel_fn *cancel) { } 96 #endif /* CONFIG_AIO */ 97 98 static inline struct kiocb *list_kiocb(struct list_head *h) 99 { 100 return list_entry(h, struct kiocb, ki_list); 101 } 102 103 /* for sysctl: */ 104 extern unsigned long aio_nr; 105 extern unsigned long aio_max_nr; 106 107 #endif /* __LINUX__AIO_H */ 108