1 files changed, 116 insertions, 0 deletions
diff --git a/include/linux/aio.h b/include/linux/aio.h
new file mode 100644
index 000000000..1bdf96533
--- /dev/null
+++ b/include/linux/aio.h
@@ -0,0 +1,116 @@
+#ifndef __LINUX__AIO_H
+#define __LINUX__AIO_H
+
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/aio_abi.h>
+#include <linux/uio.h>
+#include <linux/rcupdate.h>
+
+#include <linux/atomic.h>
+
+struct kioctx;
+struct kiocb;
+
+#define KIOCB_KEY		0
+
+/*
+ * We use ki_cancel == KIOCB_CANCELLED to indicate that a kiocb has been either
+ * cancelled or completed (this makes a certain amount of sense because
+ * successful cancellation - io_cancel() - does deliver the completion to
+ * userspace).
+ *
+ * And since most things don't implement kiocb cancellation and we'd really like
+ * kiocb completion to be lockless when possible, we use ki_cancel to
+ * synchronize cancellation and completion - we only set it to KIOCB_CANCELLED
+ * with xchg() or cmpxchg(), see batch_complete_aio() and kiocb_cancel().
+ */
+#define KIOCB_CANCELLED		((void *) (~0ULL))
+
+typedef int (kiocb_cancel_fn)(struct kiocb *, struct io_event *);
+
+struct kiocb {
+	atomic_t		ki_users;
+
+	struct file		*ki_filp;
+	struct kioctx		*ki_ctx;	/* NULL for sync ops */
+	kiocb_cancel_fn		*ki_cancel;
+	void			(*ki_dtor)(struct kiocb *);
+
+	union {
+		void __user		*user;
+		struct task_struct	*tsk;
+	} ki_obj;
+
+	__u64			ki_user_data;	/* user's data for completion */
+	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 */
+	struct iovec		ki_inline_vec;	/* inline vector */
+ 	struct iovec		*ki_iovec;
+ 	unsigned long		ki_nr_segs;
+ 	unsigned long		ki_cur_seg;
+
+	struct list_head	ki_list;	/* the aio core uses this
+						 * for cancellation */
+
+	/*
+	 * If the aio_resfd field of the userspace iocb is not zero,
+	 * this is the underlying eventfd context to deliver events to.
+	 */
+	struct eventfd_ctx	*ki_eventfd;
+};
+
+static inline bool is_sync_kiocb(struct kiocb *kiocb)
+{
+	return kiocb->ki_ctx == NULL;
+}
+
+static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
+{
+	*kiocb = (struct kiocb) {
+			.ki_users = ATOMIC_INIT(1),
+			.ki_ctx = NULL,
+			.ki_filp = filp,
+			.ki_obj.tsk = current,
+		};
+}
+
+/* prototypes */
+#ifdef CONFIG_AIO
+extern ssize_t wait_on_sync_kiocb(struct kiocb *iocb);
+extern void aio_put_req(struct kiocb *iocb);
+extern void aio_complete(struct kiocb *iocb, long res, long res2);
+struct mm_struct;
+extern void exit_aio(struct mm_struct *mm);
+extern long do_io_submit(aio_context_t ctx_id, long nr,
+			 struct iocb __user *__user *iocbpp, bool compat);
+void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel);
+#else
+static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; }
+static inline void aio_put_req(struct kiocb *iocb) { }
+static inline void aio_complete(struct kiocb *iocb, long res, long res2) { }
+struct mm_struct;
+static inline void exit_aio(struct mm_struct *mm) { }
+static inline long do_io_submit(aio_context_t ctx_id, long nr,
+				struct iocb __user * __user *iocbpp,
+				bool compat) { return 0; }
+static inline void kiocb_set_cancel_fn(struct kiocb *req,
+				       kiocb_cancel_fn *cancel) { }
+#endif /* CONFIG_AIO */
+
+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 */