sys/dev/dm/dm_target_linear.c

   1 /*        $NetBSD: dm_target_linear.c,v 1.8 2009/12/01 23:12:10 haad Exp $      */
   2
   3 /*
   4  * Copyright (c) 2008 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 /*
  34  * This file implements initial version of device-mapper dklinear target.
  35  */
  36
  37 #include <sys/types.h>
  38 #include <sys/param.h>
  39
  40 #include <sys/buf.h>
  41 #include <sys/kmem.h>
  42 #include <sys/vnode.h>
  43
  44 #include <machine/int_fmtio.h>
  45
  46 #include "dm.h"
  47
  48 /*
  49  * Allocate target specific config data, and link them to table.
  50  * This function is called only when, flags is not READONLY and
  51  * therefore we can add things to pdev list. This should not a
  52  * problem because this routine is called only from dm_table_load_ioctl.
  53  * @argv[0] is name,
  54  * @argv[1] is physical data offset.
  55  */
  56 int
  57 dm_target_linear_init(dm_dev_t * dmv, void **target_config, char *params)
  58 {
  59         dm_target_linear_config_t *tlc;
  60         dm_pdev_t *dmp;
  61
  62         char **ap, *argv[3];
  63
  64         if (params == NULL)
  65                 return EINVAL;
  66
  67         /*
  68          * Parse a string, containing tokens delimited by white space,
  69          * into an argument vector
  70          */
  71         for (ap = argv; ap < &argv[2] &&
  72             (*ap = strsep(&params, " \t")) != NULL;) {
  73                 if (**ap != '\0')
  74                         ap++;
  75         }
  76
  77         aprint_debug("Linear target init function called %s--%s!!\n",
  78             argv[0], argv[1]);
  79
  80         /* Insert dmp to global pdev list */
  81         if ((dmp = dm_pdev_insert(argv[0])) == NULL)
  82                 return ENOENT;
  83
  84         if ((tlc = kmem_alloc(sizeof(dm_target_linear_config_t), KM_SLEEP))
  85             == NULL)
  86                 return ENOMEM;
  87
  88         tlc->pdev = dmp;
  89         tlc->offset = 0;        /* default settings */
  90
  91         /* Check user input if it is not leave offset as 0. */
  92         tlc->offset = atoi(argv[1]);
  93
  94         *target_config = tlc;
  95
  96         dmv->dev_type = DM_LINEAR_DEV;
  97
  98         return 0;
  99 }
 100 /*
 101  * Status routine is called to get params string, which is target
 102  * specific. When dm_table_status_ioctl is called with flag
 103  * DM_STATUS_TABLE_FLAG I have to sent params string back.
 104  */
 105 char *
 106 dm_target_linear_status(void *target_config)
 107 {
 108         dm_target_linear_config_t *tlc;
 109         char *params;
 110         tlc = target_config;
 111
 112         aprint_debug("Linear target status function called\n");
 113
 114         if ((params = kmem_alloc(DM_MAX_PARAMS_SIZE, KM_NOSLEEP)) == NULL)
 115                 return NULL;
 116
 117         aprint_normal("%s %" PRIu64, tlc->pdev->name, tlc->offset);
 118         snprintf(params, DM_MAX_PARAMS_SIZE, "%s %" PRIu64,
 119             tlc->pdev->name, tlc->offset);
 120
 121         return params;
 122 }
 123 /*
 124  * Do IO operation, called from dmstrategy routine.
 125  */
 126 int
 127 dm_target_linear_strategy(dm_table_entry_t * table_en, struct buf * bp)
 128 {
 129         dm_target_linear_config_t *tlc;
 130
 131         tlc = table_en->target_config;
 132
 133 /*      printf("Linear target read function called %" PRIu64 "!!\n",
 134         tlc->offset);*/
 135
 136         bp->b_blkno += tlc->offset;
 137
 138         VOP_STRATEGY(tlc->pdev->pdev_vnode, bp);
 139
 140         return 0;
 141
 142 }
 143 /*
 144  * Destroy target specific data. Decrement table pdevs.
 145  */
 146 int
 147 dm_target_linear_destroy(dm_table_entry_t * table_en)
 148 {
 149         dm_target_linear_config_t *tlc;
 150
 151         /*
 152          * Destroy function is called for every target even if it
 153          * doesn't have target_config.
 154          */
 155
 156         if (table_en->target_config == NULL)
 157                 return 0;
 158
 159         tlc = table_en->target_config;
 160
 161         /* Decrement pdev ref counter if 0 remove it */
 162         dm_pdev_decr(tlc->pdev);
 163
 164         /* Unbusy target so we can unload it */
 165         dm_target_unbusy(table_en->target);
 166
 167         kmem_free(table_en->target_config, sizeof(dm_target_linear_config_t));
 168
 169         table_en->target_config = NULL;
 170
 171         return 0;
 172 }
 173 /* Add this target pdev dependiences to prop_array_t */
 174 int
 175 dm_target_linear_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
 176 {
 177         dm_target_linear_config_t *tlc;
 178         struct vattr va;
 179
 180         int error;
 181
 182         if (table_en->target_config == NULL)
 183                 return ENOENT;
 184
 185         tlc = table_en->target_config;
 186
 187         if ((error = VOP_GETATTR(tlc->pdev->pdev_vnode, &va, curlwp->l_cred)) != 0)
 188                 return error;
 189
 190         prop_array_add_uint64(prop_array, (uint64_t) va.va_rdev);
 191
 192         return 0;
 193 }
 194 /*
 195  * Register upcall device.
 196  * Linear target doesn't need any upcall devices but other targets like
 197  * mirror, snapshot, multipath, stripe will use this functionality.
 198  */
 199 int
 200 dm_target_linear_upcall(dm_table_entry_t * table_en, struct buf * bp)
 201 {
 202         return 0;
 203 }
 204 /*
 205  * Transform char s to uint64_t offset number.
 206  */
 207 uint64_t
 208 atoi(const char *s)
 209 {
 210         uint64_t n;
 211         n = 0;
 212
 213         while (*s != '\0') {
 214                 if (!isdigit(*s))
 215                         break;
 216
 217                 n = (10 * n) + (*s - '0');
 218                 s++;
 219         }
 220
 221         return n;
 222 }