http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/linux/aio.h

#ifndef __LINUX__AIO_H #define __LINUX__AIO_H #include <linux/list.h> #include <linux/workqueue.h> #include <linux/aio_abi.h> #include <asm/atomic.h> #define AIO_MAXSEGS 4 #define AIO_KIOGRP_NR_ATOMIC 8 struct kioctx; /* Notes on cancelling a kiocb: * If a kiocb is cancelled, aio_complete may return 0 to indicate * that cancel has not yet disposed of the kiocb. All cancel * operations *must* call aio_put_req to dispose of the kiocb * to guard against races with the completion code. */ #define KIOCB_C_CANCELLED 0x01 #define KIOCB_C_COMPLETE 0x02 #define KIOCB_SYNC_KEY (~0U) /* ki_flags bits */ /* * This may be used for cancel/retry serialization in the future, but * for now it's unused and we probably don't want modules to even * think they can use it. */ /* #define KIF_LOCKED 0 */ #define KIF_KICKED 1 #define KIF_CANCELLED 2 #define kiocbTryLock(iocb) test_and_set_bit(KIF_LOCKED, &(iocb)->ki_flags) #define kiocbTryKick(iocb) test_and_set_bit(KIF_KICKED, &(iocb)->ki_flags) #define kiocbSetLocked(iocb) set_bit(KIF_LOCKED, &(iocb)->ki_flags) #define kiocbSetKicked(iocb) set_bit(KIF_KICKED, &(iocb)->ki_flags) #define kiocbSetCancelled(iocb) set_bit(KIF_CANCELLED, &(iocb)->ki_flags) #define kiocbClearLocked(iocb) clear_bit(KIF_LOCKED, &(iocb)->ki_flags) #define kiocbClearKicked(iocb) clear_bit(KIF_KICKED, &(iocb)->ki_flags) #define kiocbClearCancelled(iocb) clear_bit(KIF_CANCELLED, &(iocb)->ki_flags) #define kiocbIsLocked(iocb) test_bit(KIF_LOCKED, &(iocb)->ki_flags) #define kiocbIsKicked(iocb) test_bit(KIF_KICKED, &(iocb)->ki_flags) #define kiocbIsCancelled(iocb) test_bit(KIF_CANCELLED, &(iocb)->ki_flags) /* is there a better place to document function pointer methods? */ /** * ki_retry - iocb forward progress callback * @kiocb: The kiocb struct to advance by performing an operation. * * This callback is called when the AIO core wants a given AIO operation * to make forward progress. The kiocb argument describes the operation * that is to be performed. As the operation proceeds, perhaps partially, * ki_retry is expected to update the kiocb with progress made. Typically * ki_retry is set in the AIO core and it itself calls file_operations * helpers. * * ki_retry's return value determines when the AIO operation is completed * and an event is generated in the AIO event ring. Except the special * return values described below, the value that is returned from ki_retry * is transferred directly into the completion ring as the operation's * resulting status. Once this has happened ki_retry *MUST NOT* reference * the kiocb pointer again. * * If ki_retry returns -EIOCBQUEUED it has made a promise that aio_complete() * will be called on the kiocb pointer in the future. The AIO core will * not ask the method again -- ki_retry must ensure forward progress. * aio_complete() must be called once and only once in the future, multiple * calls may result in undefined behaviour. * * If ki_retry returns -EIOCBRETRY it has made a promise that kick_iocb() * will be called on the kiocb pointer in the future. This may happen * through generic helpers that associate kiocb->ki_wait with a wait * queue head that ki_retry uses via current->io_wait. It can also happen * with custom tracking and manual calls to kick_iocb(), though that is * discouraged. In either case, kick_iocb() must be called once and only * once. ki_retry must ensure forward progress, the AIO core will wait * indefinitely for kick_iocb() to be called. */ struct kiocb { struct list_head ki_run_list; long ki_flags; int ki_users; unsigned ki_key; /* id of this request */ struct file *ki_filp; struct kioctx *ki_ctx; /* may be NULL for sync ops */ int (*ki_cancel)(struct kiocb *, struct io_event *); ssize_t (*ki_retry)(struct kiocb *); void (*ki_dtor)(struct kiocb *); union { void __user *user; struct task_struct *tsk; } ki_obj; __u64 ki_user_data; /* user's data for completion */ wait_queue_t ki_wait; loff_t ki_pos; void *private; /* State that we remember to be able to restart/retry */ unsigned short ki_opcode; size_t ki_nbytes; /* copy of iocb->aio_nbytes */ char __user *ki_buf; /* remaining iocb->aio_buf */ size_t ki_left; /* remaining bytes */ long ki_retried; /* just for testing */ long ki_kicked; /* just for testing */ long ki_queued; /* just for testing */ struct list_head ki_list; /* the aio core uses this * for cancellation */ }; #define is_sync_kiocb(iocb) ((iocb)->ki_key == KIOCB_SYNC_KEY) #define init_sync_kiocb(x, filp) \ do { \ struct task_struct *tsk = current; \ (x)->ki_flags = 0; \ (x)->ki_users = 1; \ (x)->ki_key = KIOCB_SYNC_KEY; \ (x)->ki_filp = (filp); \ (x)->ki_ctx = NULL; \ (x)->ki_cancel = NULL; \ (x)->ki_retry = NULL; \ (x)->ki_dtor = NULL; \ (x)->ki_obj.tsk = tsk; \ (x)->ki_user_data = 0; \ init_wait((&(x)->ki_wait)); \ } while (0) #define AIO_RING_MAGIC 0xa10a10a1 #define AIO_RING_COMPAT_FEATURES 1 #define AIO_RING_INCOMPAT_FEATURES 0 struct aio_ring { unsigned id; /* kernel internal index number */ unsigned nr; /* number of io_events */ unsigned head; unsigned tail; unsigned magic; unsigned compat_features; unsigned incompat_features; unsigned header_length; /* size of aio_ring */ struct io_event io_events[0]; }; /* 128 bytes + ring size */ #define aio_ring_avail(info, ring) (((ring)->head + (info)->nr - 1 - (ring)->tail) % (info)->nr) #define AIO_RING_PAGES 8 struct aio_ring_info { unsigned long mmap_base; unsigned long mmap_size; struct page **ring_pages; spinlock_t ring_lock; long nr_pages; unsigned nr, tail; struct page *internal_pages[AIO_RING_PAGES]; }; struct kioctx { atomic_t users; int dead; struct mm_struct *mm; /* This needs improving */ unsigned long user_id; struct kioctx *next; wait_queue_head_t wait; spinlock_t ctx_lock; int reqs_active; struct list_head active_reqs; /* used for cancellation */ struct list_head run_list; /* used for kicked reqs */ /* sys_io_setup currently limits this to an unsigned int */ unsigned max_reqs; struct aio_ring_info ring_info; struct work_struct wq; }; /* prototypes */ extern unsigned aio_max_size; extern ssize_t FASTCALL(wait_on_sync_kiocb(struct kiocb *iocb)); extern int FASTCALL(aio_put_req(struct kiocb *iocb)); extern void FASTCALL(kick_iocb(struct kiocb *iocb)); extern int FASTCALL(aio_complete(struct kiocb *iocb, long res, long res2)); extern void FASTCALL(__put_ioctx(struct kioctx *ctx)); struct mm_struct; extern void FASTCALL(exit_aio(struct mm_struct *mm)); extern struct kioctx *lookup_ioctx(unsigned long ctx_id); extern int FASTCALL(io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, struct iocb *iocb)); /* semi private, but used by the 32bit emulations: */ struct kioctx *lookup_ioctx(unsigned long ctx_id); int FASTCALL(io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, struct iocb *iocb)); #define get_ioctx(kioctx) do { \ BUG_ON(unlikely(atomic_read(&(kioctx)->users) <= 0)); \ atomic_inc(&(kioctx)->users); \ } while (0) #define put_ioctx(kioctx) do { \ BUG_ON(unlikely(atomic_read(&(kioctx)->users) <= 0)); \ if (unlikely(atomic_dec_and_test(&(kioctx)->users))) \ __put_ioctx(kioctx); \ } while (0) #define in_aio() !is_sync_wait(current->io_wait) /* may be used for debugging */ #define warn_if_async() \ do { \ if (in_aio()) { \ printk(KERN_ERR "%s(%s:%d) called in async context!\n", \ __FUNCTION__, __FILE__, __LINE__); \ dump_stack(); \ } \ } while (0) #define io_wait_to_kiocb(wait) container_of(wait, struct kiocb, ki_wait) #define is_retried_kiocb(iocb) ((iocb)->ki_retried > 1) #include <linux/aio_abi.h> static inline struct kiocb *list_kiocb(struct list_head *h) { return list_entry(h, struct kiocb, ki_list); } /* for sysctl: */ extern unsigned long aio_nr; extern unsigned long aio_max_nr; #endif /* __LINUX__AIO_H */