/*
 * Copyright (c) 2004, 2005 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Hiten Pandya <hmp@backplane.com>.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $DragonFly: src/sys/sys/bio.h,v 1.6 2008/07/14 03:08:58 dillon Exp $
 */

#ifndef _SYS_BIO_H_
#define _SYS_BIO_H_

#ifndef _SYS_TYPES_H_
#include <sys/types.h>
#endif
#ifndef _SYS_QUEUE_H_
#include <sys/queue.h>
#endif

struct bio;
struct bio_track;
struct disk;
typedef void biodone_t(struct bio *);

/*
 * BIO encapsulation for storage drivers and systems that do not require
 * caching support for underlying blocks.
 *
 * NOTE: bio_done and bio_caller_info belong to the caller, while
 * bio_driver_info belongs to the driver.
 *
 * bio_track is only non-NULL when an I/O is in progress.
 */
struct bio {
        TAILQ_ENTRY(bio) bio_act;       /* driver queue when active */
        TAILQ_ENTRY(bio) link;
        struct bio_track *bio_track;    /* BIO tracking structure */
        struct disk     *bio_disk;
        struct bio      *bio_prev;      /* BIO stack */
        struct bio      *bio_next;      /* BIO stack / cached translations */
        struct buf      *bio_buf;       /* High-level buffer back-pointer. */
        biodone_t       *bio_done;      /* MPSAFE caller completion function */
        off_t           bio_offset;     /* Logical offset relative to device */
        void            *bio_driver_info;
        uint32_t        bio_crc;        /* Caller-specific */
        int             bio_flags;
        union {
                void    *ptr;
                off_t   offset;
                int     index;
                u_int32_t uvalue32;
                struct buf *cluster_head;
                struct bio *cluster_parent;
        } bio_caller_info1;
        union {
                void    *ptr;
                off_t   offset;
                int     index;
                struct buf *cluster_tail;
        } bio_caller_info2;
        union {
                void    *ptr;
                int     value;
                long    lvalue;
                struct  timeval tv;
        } bio_caller_info3;
};

/*
 * BIO flags, used for strategy/biodone/biodone_sync interactions.
 */
#define BIO_SYNC        0x00000001
#define BIO_WANT        0x20000000
#define BIO_DONE        0x40000000

void bio_start_transaction(struct bio *, struct bio_track *);

#endif