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 struct file *ki_filp; 34 struct kioctx *ki_ctx; /* NULL for sync ops */ 35 kiocb_cancel_fn *ki_cancel; 36 void *private; 37 38 union { 39 void __user *user; 40 struct task_struct *tsk; 41 } ki_obj; 42 43 __u64 ki_user_data; /* user's data for completion */ 44 loff_t ki_pos; 45 size_t ki_nbytes; /* copy of iocb->aio_nbytes */ 46 47 struct list_head ki_list; /* the aio core uses this 48 * for cancellation */ 49 50 /* 51 * If the aio_resfd field of the userspace iocb is not zero, 52 * this is the underlying eventfd context to deliver events to. 53 */ 54 struct eventfd_ctx *ki_eventfd; 55 }; 56 57 static inline bool is_sync_kiocb(struct kiocb *kiocb) 58 { 59 return kiocb->ki_ctx == NULL; 60 } 61 62 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) 63 { 64 *kiocb = (struct kiocb) { 65 .ki_ctx = NULL, 66 .ki_filp = filp, 67 .ki_obj.tsk = current, 68 }; 69 } 70 71 /* prototypes */ 72 #ifdef CONFIG_AIO 73 extern ssize_t wait_on_sync_kiocb(struct kiocb *iocb); 74 extern void aio_complete(struct kiocb *iocb, long res, long res2); 75 struct mm_struct; 76 extern void exit_aio(struct mm_struct *mm); 77 extern long do_io_submit(aio_context_t ctx_id, long nr, 78 struct iocb __user *__user *iocbpp, bool compat); 79 void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel); 80 #else 81 static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; } 82 static inline void aio_complete(struct kiocb *iocb, long res, long res2) { } 83 struct mm_struct; 84 static inline void exit_aio(struct mm_struct *mm) { } 85 static inline long do_io_submit(aio_context_t ctx_id, long nr, 86 struct iocb __user * __user *iocbpp, 87 bool compat) { return 0; } 88 static inline void kiocb_set_cancel_fn(struct kiocb *req, 89 kiocb_cancel_fn *cancel) { } 90 #endif /* CONFIG_AIO */ 91 92 static inline struct kiocb *list_kiocb(struct list_head *h) 93 { 94 return list_entry(h, struct kiocb, ki_list); 95 } 96 97 /* for sysctl: */ 98 extern unsigned long aio_nr; 99 extern unsigned long aio_max_nr; 100 101 #endif /* __LINUX__AIO_H */ 102