sys/sys/bio.h

   1 /*
   2  * Copyright (c) 2004, 2005 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Hiten Pandya <hmp@backplane.com>.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/sys/bio.h,v 1.6 2008/07/14 03:08:58 dillon Exp $
  35  */
  36
  37 #ifndef _SYS_BIO_H_
  38 #define _SYS_BIO_H_
  39
  40 #ifndef _SYS_TYPES_H_
  41 #include <sys/types.h>
  42 #endif
  43 #ifndef _SYS_QUEUE_H_
  44 #include <sys/queue.h>
  45 #endif
  46
  47 struct bio;
  48 struct bio_track;
  49 struct disk;
  50 typedef void biodone_t(struct bio *);
  51
  52 /*
  53  * BIO encapsulation for storage drivers and systems that do not require
  54  * caching support for underlying blocks.
  55  *
  56  * NOTE: bio_done and bio_caller_info belong to the caller, while
  57  * bio_driver_info belongs to the driver.
  58  *
  59  * bio_track is only non-NULL when an I/O is in progress.
  60  */
  61 struct bio {
  62         TAILQ_ENTRY(bio) bio_act;       /* driver queue when active */
  63         TAILQ_ENTRY(bio) link;
  64         struct bio_track *bio_track;    /* BIO tracking structure */
  65         struct disk     *bio_disk;
  66         struct bio      *bio_prev;      /* BIO stack */
  67         struct bio      *bio_next;      /* BIO stack / cached translations */
  68         struct buf      *bio_buf;       /* High-level buffer back-pointer. */
  69         biodone_t       *bio_done;      /* MPSAFE caller completion function */
  70         off_t           bio_offset;     /* Logical offset relative to device */
  71         void            *bio_driver_info;
  72         uint32_t        bio_crc;        /* Caller-specific */
  73         int             bio_flags;
  74         union {
  75                 void    *ptr;
  76                 off_t   offset;
  77                 int     index;
  78                 u_int32_t uvalue32;
  79                 struct buf *cluster_head;
  80                 struct bio *cluster_parent;
  81         } bio_caller_info1;
  82         union {
  83                 void    *ptr;
  84                 off_t   offset;
  85                 int     index;
  86                 struct buf *cluster_tail;
  87         } bio_caller_info2;
  88         union {
  89                 void    *ptr;
  90                 int     value;
  91                 long    lvalue;
  92                 struct  timeval tv;
  93         } bio_caller_info3;
  94 };
  95
  96 /*
  97  * BIO flags, used for strategy/biodone/biodone_sync interactions.
  98  */
  99 #define BIO_SYNC        0x00000001
 100 #define BIO_WANT        0x20000000
 101 #define BIO_DONE        0x40000000
 102
 103 void bio_start_transaction(struct bio *, struct bio_track *);
 104
 105 #endif