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dm_dev.c revision 1.12 
      1 /*        $NetBSD: dm_dev.c,v 1.12 2019/12/03 16:22:01 tkusumi 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 #include <sys/cdefs.h>
     32 __KERNEL_RCSID(0, "$NetBSD: dm_dev.c,v 1.12 2019/12/03 16:22:01 tkusumi Exp $");
     33 
     34 #include <sys/types.h>
     35 #include <sys/param.h>
     36 
     37 #include <sys/disk.h>
     38 #include <sys/disklabel.h>
     39 #include <sys/ioctl.h>
     40 #include <sys/ioccom.h>
     41 #include <sys/kmem.h>
     42 
     43 #include "netbsd-dm.h"
     44 #include "dm.h"
     45 
     46 static dm_dev_t *dm_dev_lookup_name(const char *);
     47 static dm_dev_t *dm_dev_lookup_uuid(const char *);
     48 static dm_dev_t *dm_dev_lookup_minor(int);
     49 
     50 static struct dm_dev_head dm_dev_list =
     51 TAILQ_HEAD_INITIALIZER(dm_dev_list);
     52 
     53 static kmutex_t dm_dev_mutex;
     54 
     55 /* dm_dev_mutex must be holdby caller before using disable_dev. */
     56 __inline static void
     57 disable_dev(dm_dev_t * dmv)
     58 {
     59 	TAILQ_REMOVE(&dm_dev_list, dmv, next_devlist);
     60 	mutex_enter(&dmv->dev_mtx);
     61 	mutex_exit(&dm_dev_mutex);
     62 	while (dmv->ref_cnt != 0)
     63 		cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
     64 	mutex_exit(&dmv->dev_mtx);
     65 }
     66 
     67 /*
     68  * Generic function used to lookup dm_dev_t. Calling with dm_dev_name
     69  * and dm_dev_uuid NULL is allowed.
     70  */
     71 dm_dev_t *
     72 dm_dev_lookup(const char *dm_dev_name, const char *dm_dev_uuid,
     73     int dm_dev_minor)
     74 {
     75 	dm_dev_t *dmv;
     76 
     77 	dmv = NULL;
     78 	mutex_enter(&dm_dev_mutex);
     79 
     80 	/* KASSERT(dm_dev_name != NULL && dm_dev_uuid != NULL && dm_dev_minor
     81 	 * > 0); */
     82 	if (dm_dev_minor > 0)
     83 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) {
     84 			dm_dev_busy(dmv);
     85 			mutex_exit(&dm_dev_mutex);
     86 			return dmv;
     87 		}
     88 	if (dm_dev_name != NULL)
     89 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) {
     90 			dm_dev_busy(dmv);
     91 			mutex_exit(&dm_dev_mutex);
     92 			return dmv;
     93 		}
     94 	if (dm_dev_uuid != NULL)
     95 		if ((dmv = dm_dev_lookup_uuid(dm_dev_uuid)) != NULL) {
     96 			dm_dev_busy(dmv);
     97 			mutex_exit(&dm_dev_mutex);
     98 			return dmv;
     99 		}
    100 	mutex_exit(&dm_dev_mutex);
    101 	return NULL;
    102 }
    103 
    104 /*
    105  * Lookup device with its minor number.
    106  */
    107 static dm_dev_t *
    108 dm_dev_lookup_minor(int dm_dev_minor)
    109 {
    110 	dm_dev_t *dmv;
    111 
    112 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
    113 		if (dm_dev_minor == dmv->minor)
    114 			return dmv;
    115 	}
    116 
    117 	return NULL;
    118 }
    119 
    120 /*
    121  * Lookup device with its device name.
    122  */
    123 static dm_dev_t *
    124 dm_dev_lookup_name(const char *dm_dev_name)
    125 {
    126 	dm_dev_t *dmv;
    127 	size_t dlen;
    128 	size_t slen;
    129 
    130 	slen = strlen(dm_dev_name);
    131 
    132 	if (slen == 0)
    133 		return NULL;
    134 
    135 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
    136 
    137 		dlen = strlen(dmv->name);
    138 
    139 		if (slen != dlen)
    140 			continue;
    141 
    142 		if (strncmp(dm_dev_name, dmv->name, slen) == 0)
    143 			return dmv;
    144 	}
    145 
    146 	return NULL;
    147 }
    148 
    149 /*
    150  * Lookup device with its device uuid. Used mostly by LVM2tools.
    151  */
    152 static dm_dev_t *
    153 dm_dev_lookup_uuid(const char *dm_dev_uuid)
    154 {
    155 	dm_dev_t *dmv;
    156 	size_t len;
    157 
    158 	len = 0;
    159 	len = strlen(dm_dev_uuid);
    160 
    161 	if (len == 0)
    162 		return NULL;
    163 
    164 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
    165 
    166 		if (strlen(dmv->uuid) != len)
    167 			continue;
    168 
    169 		if (strncmp(dm_dev_uuid, dmv->uuid, strlen(dmv->uuid)) == 0)
    170 			return dmv;
    171 	}
    172 
    173 	return NULL;
    174 }
    175 
    176 /*
    177  * Insert new device to the global list of devices.
    178  */
    179 int
    180 dm_dev_insert(dm_dev_t * dev)
    181 {
    182 	dm_dev_t *dmv;
    183 	int r;
    184 
    185 	dmv = NULL;
    186 	r = 0;
    187 
    188 	KASSERT(dev != NULL);
    189 	mutex_enter(&dm_dev_mutex);
    190 	if (((dmv = dm_dev_lookup_uuid(dev->uuid)) == NULL) &&
    191 	    ((dmv = dm_dev_lookup_name(dev->name)) == NULL) &&
    192 	    ((dmv = dm_dev_lookup_minor(dev->minor)) == NULL)) {
    193 
    194 		TAILQ_INSERT_TAIL(&dm_dev_list, dev, next_devlist);
    195 
    196 	} else
    197 		r = EEXIST;
    198 
    199 	mutex_exit(&dm_dev_mutex);
    200 	return r;
    201 }
    202 
    203 #ifdef notyet
    204 /*
    205  * Lookup device with its minor number.
    206  */
    207 int
    208 dm_dev_test_minor(int dm_dev_minor)
    209 {
    210 	dm_dev_t *dmv;
    211 
    212 	mutex_enter(&dm_dev_mutex);
    213 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
    214 		if (dm_dev_minor == dmv->minor) {
    215 			mutex_exit(&dm_dev_mutex);
    216 			return 1;
    217 		}
    218 	}
    219 	mutex_exit(&dm_dev_mutex);
    220 
    221 	return 0;
    222 }
    223 #endif
    224 
    225 /*
    226  * dm_dev_lookup_devt look for selected device_t. We keep this routine
    227  * outside of dm_dev_lookup because it is a temporally solution.
    228  *
    229  * TODO: This is a hack autoconf should be more flexible.
    230  */
    231 dm_dev_t *
    232 dm_dev_detach(device_t devt)
    233 {
    234 	dm_dev_t *dmv;
    235 
    236 	mutex_enter(&dm_dev_mutex);
    237 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
    238 		if (devt == dmv->devt) {
    239 			disable_dev(dmv);
    240 			return dmv;
    241 		}
    242 	}
    243 	mutex_exit(&dm_dev_mutex);
    244 
    245 	return NULL;
    246 }
    247 
    248 /*
    249  * Remove device selected with dm_dev from global list of devices.
    250  */
    251 dm_dev_t *
    252 dm_dev_rem(const char *dm_dev_name, const char *dm_dev_uuid,
    253     int dm_dev_minor)
    254 {
    255 	dm_dev_t *dmv;
    256 	dmv = NULL;
    257 
    258 	mutex_enter(&dm_dev_mutex);
    259 
    260 	if (dm_dev_minor > 0)
    261 		if ((dmv = dm_dev_lookup_minor(dm_dev_minor)) != NULL) {
    262 			disable_dev(dmv);
    263 			return dmv;
    264 		}
    265 	if (dm_dev_name != NULL)
    266 		if ((dmv = dm_dev_lookup_name(dm_dev_name)) != NULL) {
    267 			disable_dev(dmv);
    268 			return dmv;
    269 		}
    270 	if (dm_dev_uuid != NULL)
    271 		if ((dmv = dm_dev_lookup_name(dm_dev_uuid)) != NULL) {
    272 			disable_dev(dmv);
    273 			return dmv;
    274 		}
    275 	mutex_exit(&dm_dev_mutex);
    276 
    277 	return NULL;
    278 }
    279 
    280 /*
    281  * Destroy all devices created in device-mapper. Remove all tables
    282  * free all allocated memmory.
    283  */
    284 int
    285 dm_dev_destroy(void)
    286 {
    287 	dm_dev_t *dmv;
    288 	mutex_enter(&dm_dev_mutex);
    289 
    290 	while (TAILQ_FIRST(&dm_dev_list) != NULL) {
    291 
    292 		dmv = TAILQ_FIRST(&dm_dev_list);
    293 
    294 		TAILQ_REMOVE(&dm_dev_list, TAILQ_FIRST(&dm_dev_list),
    295 		    next_devlist);
    296 
    297 		mutex_enter(&dmv->dev_mtx);
    298 
    299 		while (dmv->ref_cnt != 0)
    300 			cv_wait(&dmv->dev_cv, &dmv->dev_mtx);
    301 
    302 		/* Destroy active table first.  */
    303 		dm_table_destroy(&dmv->table_head, DM_TABLE_ACTIVE);
    304 
    305 		/* Destroy inactive table if exits, too. */
    306 		dm_table_destroy(&dmv->table_head, DM_TABLE_INACTIVE);
    307 
    308 		dm_table_head_destroy(&dmv->table_head);
    309 
    310 		mutex_exit(&dmv->dev_mtx);
    311 		mutex_destroy(&dmv->dev_mtx);
    312 		cv_destroy(&dmv->dev_cv);
    313 
    314 		(void) kmem_free(dmv, sizeof(dm_dev_t));
    315 	}
    316 	mutex_exit(&dm_dev_mutex);
    317 
    318 	mutex_destroy(&dm_dev_mutex);
    319 	return 0;
    320 }
    321 
    322 /*
    323  * Allocate new device entry.
    324  */
    325 dm_dev_t *
    326 dm_dev_alloc(void)
    327 {
    328 	dm_dev_t *dmv;
    329 
    330 	dmv = kmem_zalloc(sizeof(dm_dev_t), KM_SLEEP);
    331 	dmv->diskp = kmem_zalloc(sizeof(struct disk), KM_SLEEP);
    332 	return dmv;
    333 }
    334 
    335 /*
    336  * Freed device entry.
    337  */
    338 int
    339 dm_dev_free(dm_dev_t * dmv)
    340 {
    341 	KASSERT(dmv != NULL);
    342 
    343 	mutex_destroy(&dmv->dev_mtx);
    344 	mutex_destroy(&dmv->diskp_mtx);
    345 	cv_destroy(&dmv->dev_cv);
    346 
    347 	if (dmv->diskp != NULL)
    348 		(void) kmem_free(dmv->diskp, sizeof(struct disk));
    349 
    350 	(void) kmem_free(dmv, sizeof(dm_dev_t));
    351 
    352 	return 0;
    353 }
    354 
    355 void
    356 dm_dev_busy(dm_dev_t * dmv)
    357 {
    358 	mutex_enter(&dmv->dev_mtx);
    359 	dmv->ref_cnt++;
    360 	mutex_exit(&dmv->dev_mtx);
    361 }
    362 
    363 void
    364 dm_dev_unbusy(dm_dev_t * dmv)
    365 {
    366 	KASSERT(dmv->ref_cnt != 0);
    367 
    368 	mutex_enter(&dmv->dev_mtx);
    369 	if (--dmv->ref_cnt == 0)
    370 		cv_broadcast(&dmv->dev_cv);
    371 	mutex_exit(&dmv->dev_mtx);
    372 }
    373 
    374 /*
    375  * Return prop_array of dm_targer_list dictionaries.
    376  */
    377 prop_array_t
    378 dm_dev_prop_list(void)
    379 {
    380 	dm_dev_t *dmv;
    381 	prop_array_t dev_array;
    382 	prop_dictionary_t dev_dict;
    383 
    384 	dev_array = prop_array_create();
    385 
    386 	mutex_enter(&dm_dev_mutex);
    387 
    388 	TAILQ_FOREACH(dmv, &dm_dev_list, next_devlist) {
    389 		dev_dict = prop_dictionary_create();
    390 
    391 		prop_dictionary_set_cstring(dev_dict, DM_DEV_NAME, dmv->name);
    392 		prop_dictionary_set_uint32(dev_dict, DM_DEV_DEV, dmv->minor);
    393 
    394 		prop_array_add(dev_array, dev_dict);
    395 		prop_object_release(dev_dict);
    396 	}
    397 
    398 	mutex_exit(&dm_dev_mutex);
    399 	return dev_array;
    400 }
    401 
    402 /*
    403  * Initialize global device mutex.
    404  */
    405 int
    406 dm_dev_init(void)
    407 {
    408 	TAILQ_INIT(&dm_dev_list);	/* initialize global dev list */
    409 	mutex_init(&dm_dev_mutex, MUTEX_DEFAULT, IPL_NONE);
    410 	return 0;
    411 }
    412