sys/dev/disk/dm/mirror/dm_target_mirror.c

   1 /*$NetBSD: dm_target_mirror.c,v 1.8 2010/01/04 00:12:22 haad Exp $*/
   2
   3 /*
   4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Adam Hamsik.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * This file implements initial version of device-mapper mirror target.
  34  */
  35 #include <dev/disk/dm/dm.h>
  36
  37 typedef struct target_mirror_config {
  38 #define MAX_MIRROR_COPIES 4
  39         dm_pdev_t *orig;
  40         dm_pdev_t *copies[MAX_MIRROR_COPIES];
  41
  42         /* copied blocks bitmaps administration etc*/
  43         dm_pdev_t *log_pdev;    /* for administration */
  44         uint64_t log_regionsize;        /* blocksize of mirror */
  45
  46         /* list of parts that still need copied etc.; run length encoded? */
  47 } dm_target_mirror_config_t;
  48
  49 int dm_target_mirror_init(dm_table_entry_t *, int, char **);
  50 char *dm_target_mirror_table(void *);
  51 int dm_target_mirror_strategy(dm_table_entry_t *, struct buf *);
  52 int dm_target_mirror_deps(dm_table_entry_t *, prop_array_t);
  53 int dm_target_mirror_destroy(dm_table_entry_t *);
  54
  55 /*
  56  * Init function called from dm_table_load_ioctl.
  57  * start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN
  58  * 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0
  59  */
  60 int
  61 dm_target_mirror_init(dm_table_entry_t *table_en, int argc, char **argv)
  62 {
  63
  64         kprintf("Mirror target init function called!!\n");
  65
  66         return ENOSYS;
  67 }
  68
  69 /* Table routine called to get params string. */
  70 char *
  71 dm_target_mirror_table(void *target_config)
  72 {
  73         return NULL;
  74 }
  75
  76 /* Strategy routine called from dm_strategy. */
  77 int
  78 dm_target_mirror_strategy(dm_table_entry_t *table_en, struct buf *bp)
  79 {
  80
  81         kprintf("Mirror target read function called!!\n");
  82
  83         bp->b_error = EIO;
  84         bp->b_resid = 0;
  85
  86         biodone(bp);
  87
  88         return 0;
  89 }
  90
  91 /* Doesn't do anything here. */
  92 int
  93 dm_target_mirror_destroy(dm_table_entry_t *table_en)
  94 {
  95         /* Unbusy target so we can unload it */
  96         dm_target_unbusy(table_en->target);
  97
  98         return 0;
  99 }
 100
 101 /* Doesn't not need to do anything here. */
 102 int
 103 dm_target_mirror_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
 104 {
 105         return 0;
 106 }