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dm_dev.c revision 1.2.6.1 
      1 /*        $NetBSD: dm_dev.c,v 1.2.6.1 2009/05/13 17:19:16 jym 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 #include <sys/types.h>
     33 #include <sys/param.h>
     34 
     35 #include <sys/disk.h>
     36 #include <sys/disklabel.h>
     37 #include <sys/ioctl.h>
     38 #include <sys/ioccom.h>
     39 #include <sys/kmem.h>
     40 
     41 #include "netbsd-dm.h"
     42 #include "dm.h"
     43 
     44 static dm_dev_t* dm_dev_lookup_name(const char *);
     45 static dm_dev_t* dm_dev_lookup_uuid(const char *);
     46 static dm_dev_t* dm_dev_lookup_minor(int);
     47 
     48 static struct dm_dev_head dm_dev_list =
     49 TAILQ_HEAD_INITIALIZER(dm_dev_list);
     50 
     51 kmutex_t dm_dev_mutex;
     52 
     53 __inline static void
     54 disable_dev(dm_dev_t *dmv)
     55 {
     56 		TAILQ_REMOVE(&dm_dev_list, dmv, next_devlist);
     57                 mutex_enter(&dmv->dev_mtx);
     58                 mutex_exit(&dm_dev_mutex);
     59                 while(dmv->ref_cnt != 0)
     60 	              cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
     61                 mutex_exit(&dmv->dev_mtx);
     62 }
     63 
     64 /*
     65  * Generic function used to lookup dm_dev_t. Calling with dm_dev_name
     66  * and dm_dev_uuid NULL is allowed.
     67  */
     68 dm_dev_t*
     69 dm_dev_lookup(const char *dm_dev_name, const char *dm_dev_uuid,
     70  	int dm_dev_minor)
     71 {
     72 	dm_dev_t *dmv;
     73 
     74 	dmv = NULL;
     75 	mutex_enter(&dm_dev_mutex);
     76 
     77 	/* KASSERT(dm_dev_name != NULL && dm_dev_uuid != NULL && dm_dev_minor > 0); */
     78 	if (dm_dev_minor > 0)
     79 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL){
     80 			dm_dev_busy(dmv);
     81 			mutex_exit(&dm_dev_mutex);
     82 			return dmv;
     83 		}
     84 
     85 	if (dm_dev_name != NULL)
     86 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL){
     87 			dm_dev_busy(dmv);
     88 			mutex_exit(&dm_dev_mutex);
     89 			return dmv;
     90 		}
     91 
     92 	if (dm_dev_uuid != NULL)
     93 		if ((dmv = dm_dev_lookup_uuid(dm_dev_uuid)) != NULL){
     94 			dm_dev_busy(dmv);
     95 			mutex_exit(&dm_dev_mutex);
     96 			return dmv;
     97 		}
     98 	mutex_exit(&dm_dev_mutex);
     99 	return NULL;
    100 }
    101 
    102 
    103 /*
    104  * Lookup device with its minor number.
    105  */
    106 static dm_dev_t*
    107 dm_dev_lookup_minor(int dm_dev_minor)
    108 {
    109 	dm_dev_t *dmv;
    110 
    111 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist){
    112 		if (dm_dev_minor == dmv->minor)
    113 			return dmv;
    114 	}
    115 
    116 	return NULL;
    117 }
    118 
    119 /*
    120  * Lookup device with it's device name.
    121  */
    122 static dm_dev_t*
    123 dm_dev_lookup_name(const char *dm_dev_name)
    124 {
    125 	dm_dev_t *dmv;
    126 	int dlen; int slen;
    127 
    128 	slen = strlen(dm_dev_name);
    129 
    130 	if (slen == 0)
    131 		return NULL;
    132 
    133 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist){
    134 
    135 		dlen = strlen(dmv->name);
    136 
    137 		if(slen != dlen)
    138 			continue;
    139 
    140 		if (strncmp(dm_dev_name, dmv->name, slen) == 0)
    141 			return dmv;
    142 	}
    143 
    144 	return NULL;
    145 }
    146 
    147 /*
    148  * Lookup device with it's device uuid. Used mostly by LVM2tools.
    149  */
    150 static dm_dev_t*
    151 dm_dev_lookup_uuid(const char *dm_dev_uuid)
    152 {
    153 	dm_dev_t *dmv;
    154 	size_t len;
    155 
    156 	len = 0;
    157 	len = strlen(dm_dev_uuid);
    158 
    159 	if (len == 0)
    160 		return NULL;
    161 
    162 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist){
    163 
    164 		if (strlen(dmv->uuid) != len)
    165 			continue;
    166 
    167 		if (strncmp(dm_dev_uuid, dmv->uuid, strlen(dmv->uuid)) == 0)
    168 			return dmv;
    169 	}
    170 
    171 	return NULL;
    172 }
    173 
    174 /*
    175  * Insert new device to the global list of devices.
    176  */
    177 int
    178 dm_dev_insert(dm_dev_t *dev)
    179 {
    180 	dm_dev_t *dmv;
    181 	int r;
    182 
    183 	dmv = NULL;
    184 	r = 0;
    185 
    186 	KASSERT(dev != NULL);
    187 	mutex_enter(&dm_dev_mutex);
    188 	if (((dmv = dm_dev_lookup_uuid(dev->uuid)) == NULL) &&
    189 	    ((dmv = dm_dev_lookup_name(dev->name)) == NULL) &&
    190 	    ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)){
    191 
    192 		TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist);
    193 
    194 	} else
    195 		r = EEXIST;
    196 
    197 	mutex_exit(&dm_dev_mutex);
    198 	return r;
    199 }
    200 
    201 #ifdef notyet
    202 /*
    203  * Lookup device with its minor number.
    204  */
    205 int
    206 dm_dev_test_minor(int dm_dev_minor)
    207 {
    208 	dm_dev_t *dmv;
    209 
    210 	mutex_enter(&dm_dev_mutex);
    211 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist){
    212 		if (dm_dev_minor == dmv->minor){
    213 			mutex_exit(&dm_dev_mutex);
    214 			return 1;
    215 		}
    216 	}
    217 	mutex_exit(&dm_dev_mutex);
    218 
    219 	return 0;
    220 }
    221 #endif
    222 
    223 /*
    224  * Remove device selected with dm_dev from global list of devices.
    225  */
    226 dm_dev_t*
    227 dm_dev_rem(const char *dm_dev_name, const char *dm_dev_uuid,
    228  	int dm_dev_minor)
    229 {
    230 	dm_dev_t *dmv;
    231 	dmv = NULL;
    232 
    233 	mutex_enter(&dm_dev_mutex);
    234 
    235 	if (dm_dev_minor > 0)
    236 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL){
    237 			disable_dev(dmv);
    238 			return dmv;
    239 		}
    240 
    241 	if (dm_dev_name != NULL)
    242 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL){
    243 			disable_dev(dmv);
    244 			return dmv;
    245 		}
    246 
    247 	if (dm_dev_uuid != NULL)
    248 		if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL){
    249 			disable_dev(dmv);
    250 			return dmv;
    251 		}
    252 	mutex_exit(&dm_dev_mutex);
    253 
    254 	return NULL;
    255 }
    256 
    257 /*
    258  * Destroy all devices created in device-mapper. Remove all tables
    259  * free all allocated memmory.
    260  */
    261 int
    262 dm_dev_destroy(void)
    263 {
    264 	dm_dev_t *dmv;
    265 	mutex_enter(&dm_dev_mutex);
    266 
    267 	while (TAILQ_FIRST(&dm_dev_list) != NULL){
    268 
    269 		dmv = TAILQ_FIRST(&dm_dev_list);
    270 
    271 		TAILQ_REMOVE(&dm_dev_list, TAILQ_FIRST(&dm_dev_list),
    272 		    next_devlist);
    273 
    274 		mutex_enter(&dmv->dev_mtx);
    275 
    276 		while (dmv->ref_cnt != 0)
    277 			cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
    278 
    279 		/* Destroy active table first.  */
    280 		dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE);
    281 
    282 		/* Destroy inactive table if exits, too. */
    283 		dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
    284 
    285 		dm_table_head_destroy(&dmv->table_head);
    286 
    287 		mutex_exit(&dmv->dev_mtx);
    288 		mutex_destroy(&dmv->dev_mtx);
    289 		cv_destroy(&dmv->dev_cv);
    290 
    291 		(void)kmem_free(dmv, sizeof(dm_dev_t));
    292 	}
    293 	mutex_exit(&dm_dev_mutex);
    294 
    295 	mutex_destroy(&dm_dev_mutex);
    296        	return 0;
    297 }
    298 
    299 /*
    300  * Allocate new device entry.
    301  */
    302 dm_dev_t*
    303 dm_dev_alloc(void)
    304 {
    305 	dm_dev_t *dmv;
    306 
    307 	dmv = kmem_zalloc(sizeof(dm_dev_t), KM_NOSLEEP);
    308 
    309 	if(dmv != NULL)
    310 		dmv->diskp = kmem_zalloc(sizeof(struct disk), KM_NOSLEEP);
    311 
    312 	return dmv;
    313 }
    314 
    315 /*
    316  * Freed device entry.
    317  */
    318 int
    319 dm_dev_free(dm_dev_t *dmv)
    320 {
    321 	KASSERT(dmv != NULL);
    322 
    323 	mutex_destroy(&dmv->dev_mtx);
    324 	cv_destroy(&dmv->dev_cv);
    325 
    326 	if(dmv->diskp != NULL)
    327 		(void)kmem_free(dmv->diskp, sizeof(struct disk));
    328 
    329 	(void)kmem_free(dmv, sizeof(dm_dev_t));
    330 
    331 	return 0;
    332 }
    333 
    334 void
    335 dm_dev_busy(dm_dev_t *dmv)
    336 {
    337 	mutex_enter(&dmv->dev_mtx);
    338 	dmv->ref_cnt++;
    339 	mutex_exit(&dmv->dev_mtx);
    340 }
    341 
    342 void
    343 dm_dev_unbusy(dm_dev_t *dmv)
    344 {
    345 	KASSERT(dmv->ref_cnt != 0);
    346 
    347 	mutex_enter(&dmv->dev_mtx);
    348 	if (--dmv->ref_cnt == 0)
    349 		cv_broadcast(&dmv->dev_cv);
    350 	mutex_exit(&dmv->dev_mtx);
    351 }
    352 
    353 /*
    354  * Return prop_array of dm_targer_list dictionaries.
    355  */
    356 prop_array_t
    357 dm_dev_prop_list(void)
    358 {
    359 	dm_dev_t *dmv;
    360 	prop_array_t dev_array;
    361 	prop_dictionary_t dev_dict;
    362 
    363 	dev_array = prop_array_create();
    364 
    365 	mutex_enter(&dm_dev_mutex);
    366 
    367 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
    368 		dev_dict  = prop_dictionary_create();
    369 
    370 		prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name);
    371 		prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor);
    372 
    373 		prop_array_add(dev_array, dev_dict);
    374 		prop_object_release(dev_dict);
    375 	}
    376 
    377 	mutex_exit(&dm_dev_mutex);
    378 	return dev_array;
    379 }
    380 
    381 /*
    382  * Initialize global device mutex.
    383  */
    384 int
    385 dm_dev_init(void)
    386 {
    387 	TAILQ_INIT(&dm_dev_list); /* initialize global dev list */
    388 	mutex_init(&dm_dev_mutex, MUTEX_DEFAULT, IPL_NONE);
    389 	return 0;
    390 }
    391