Home | History | Annotate | Line # | Download | only in dm
      1 /*        $NetBSD: dm_target.c,v 1.42 2021/08/21 22:23:33 andvar 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_target.c,v 1.42 2021/08/21 22:23:33 andvar Exp $");
     33 
     34 #include <sys/types.h>
     35 #include <sys/param.h>
     36 #include <sys/kmem.h>
     37 #include <sys/module.h>
     38 
     39 #include "netbsd-dm.h"
     40 #include "dm.h"
     41 
     42 static dm_target_t *dm_target_lookup_name(const char *);
     43 
     44 TAILQ_HEAD(dm_target_head, dm_target);
     45 
     46 static struct dm_target_head dm_target_list =
     47 TAILQ_HEAD_INITIALIZER(dm_target_list);
     48 
     49 static kmutex_t dm_target_mutex;
     50 
     51 /*
     52  * Called indirectly from dm_table_load_ioctl to mark target as used.
     53  */
     54 void
     55 dm_target_busy(dm_target_t *target)
     56 {
     57 
     58 	atomic_inc_32(&target->ref_cnt);
     59 }
     60 
     61 /*
     62  * Release reference counter on target.
     63  */
     64 void
     65 dm_target_unbusy(dm_target_t *target)
     66 {
     67 
     68 	KASSERT(target->ref_cnt > 0);
     69 	atomic_dec_32(&target->ref_cnt);
     70 }
     71 
     72 /*
     73  * Try to autoload target module if it was not found in current
     74  * target list.
     75  */
     76 dm_target_t *
     77 dm_target_autoload(const char *dm_target_name)
     78 {
     79 	char name[30];
     80 	unsigned int gen;
     81 	dm_target_t *dmt;
     82 
     83 	snprintf(name, sizeof(name), "dm_target_%s", dm_target_name);
     84 	name[29] = '\0';
     85 
     86 	do {
     87 		gen = module_gen;
     88 
     89 		/* Try to autoload target module */
     90 		module_autoload(name, MODULE_CLASS_MISC);
     91 	} while (gen != module_gen);
     92 
     93 	mutex_enter(&dm_target_mutex);
     94 	dmt = dm_target_lookup_name(dm_target_name);
     95 	if (dmt != NULL)
     96 		dm_target_busy(dmt);
     97 	mutex_exit(&dm_target_mutex);
     98 
     99 	return dmt;
    100 }
    101 
    102 /*
    103  * Lookup for target in global target list.
    104  */
    105 dm_target_t *
    106 dm_target_lookup(const char *dm_target_name)
    107 {
    108 	dm_target_t *dmt;
    109 
    110 	if (dm_target_name == NULL)
    111 		return NULL;
    112 
    113 	mutex_enter(&dm_target_mutex);
    114 
    115 	dmt = dm_target_lookup_name(dm_target_name);
    116 	if (dmt != NULL)
    117 		dm_target_busy(dmt);
    118 
    119 	mutex_exit(&dm_target_mutex);
    120 
    121 	return dmt;
    122 }
    123 
    124 /*
    125  * Search for name in TAIL and return appropriate pointer.
    126  */
    127 static dm_target_t *
    128 dm_target_lookup_name(const char *dm_target_name)
    129 {
    130 	dm_target_t *dm_target;
    131 	size_t dlen;
    132 	size_t slen;
    133 
    134 	slen = strlen(dm_target_name) + 1;
    135 
    136 	TAILQ_FOREACH(dm_target, &dm_target_list, dm_target_next) {
    137 		dlen = strlen(dm_target->name) + 1;
    138 		if (dlen != slen)
    139 			continue;
    140 
    141 		if (strncmp(dm_target_name, dm_target->name, slen) == 0)
    142 			return dm_target;
    143 	}
    144 
    145 	return NULL;
    146 }
    147 
    148 /*
    149  * Insert new target struct into the TAIL.
    150  * dm_target
    151  *   contains name, version, function pointer to specific target functions.
    152  */
    153 int
    154 dm_target_insert(dm_target_t *dm_target)
    155 {
    156 	dm_target_t *dmt;
    157 
    158 	/* Sanity check for any missing function */
    159 	if (dm_target->init == NULL) {
    160 		printf("%s missing init\n", dm_target->name);
    161 		return EINVAL;
    162 	}
    163 	if (dm_target->strategy == NULL) {
    164 		printf("%s missing strategy\n", dm_target->name);
    165 		return EINVAL;
    166 	}
    167 	if (dm_target->destroy == NULL) {
    168 		printf("%s missing destroy\n", dm_target->name);
    169 		return EINVAL;
    170 	}
    171 #if 0
    172 	if (dm_target->upcall == NULL) {
    173 		printf("%s missing upcall\n", dm_target->name);
    174 		return EINVAL;
    175 	}
    176 #endif
    177 
    178 	mutex_enter(&dm_target_mutex);
    179 
    180 	dmt = dm_target_lookup_name(dm_target->name);
    181 	if (dmt != NULL) {
    182 		mutex_exit(&dm_target_mutex);
    183 		return EEXIST;
    184 	}
    185 	TAILQ_INSERT_TAIL(&dm_target_list, dm_target, dm_target_next);
    186 
    187 	mutex_exit(&dm_target_mutex);
    188 
    189 	return 0;
    190 }
    191 
    192 /*
    193  * Remove target from TAIL, target is selected with its name.
    194  */
    195 int
    196 dm_target_rem(const char *dm_target_name)
    197 {
    198 	dm_target_t *dmt;
    199 
    200 	KASSERT(dm_target_name != NULL);
    201 
    202 	mutex_enter(&dm_target_mutex);
    203 
    204 	dmt = dm_target_lookup_name(dm_target_name);
    205 	if (dmt == NULL) {
    206 		mutex_exit(&dm_target_mutex);
    207 		return ENOENT;
    208 	}
    209 	if (dmt->ref_cnt > 0) {
    210 		mutex_exit(&dm_target_mutex);
    211 		return EBUSY;
    212 	}
    213 	TAILQ_REMOVE(&dm_target_list, dmt, dm_target_next);
    214 
    215 	mutex_exit(&dm_target_mutex);
    216 
    217 	kmem_free(dmt, sizeof(dm_target_t));
    218 
    219 	return 0;
    220 }
    221 
    222 /*
    223  * Destroy all targets and remove them from queue.
    224  * This routine is called from dm_detach, before module
    225  * is unloaded.
    226  */
    227 int
    228 dm_target_destroy(void)
    229 {
    230 	dm_target_t *dm_target;
    231 
    232 	mutex_enter(&dm_target_mutex);
    233 
    234 	while ((dm_target = TAILQ_FIRST(&dm_target_list)) != NULL) {
    235 		TAILQ_REMOVE(&dm_target_list, dm_target, dm_target_next);
    236 		kmem_free(dm_target, sizeof(dm_target_t));
    237 	}
    238 	KASSERT(TAILQ_EMPTY(&dm_target_list));
    239 
    240 	mutex_exit(&dm_target_mutex);
    241 
    242 	mutex_destroy(&dm_target_mutex);
    243 #if 0
    244 	/* Target specific module destroy routine. */
    245 	dm_target_delay_pool_destroy();
    246 #endif
    247 	return 0;
    248 }
    249 
    250 /*
    251  * Allocate new target entry.
    252  */
    253 dm_target_t *
    254 dm_target_alloc(const char *name)
    255 {
    256 	dm_target_t *dmt;
    257 
    258 	dmt = kmem_zalloc(sizeof(dm_target_t), KM_SLEEP);
    259 	if (dmt == NULL)
    260 		return NULL;
    261 
    262 	if (name)
    263 		strlcpy(dmt->name, name, sizeof(dmt->name));
    264 
    265 	return dmt;
    266 }
    267 
    268 /*
    269  * Return prop_array of dm_target dictionaries.
    270  */
    271 prop_array_t
    272 dm_target_prop_list(void)
    273 {
    274 	prop_array_t target_array;
    275 	dm_target_t *dm_target;
    276 
    277 	target_array = prop_array_create();
    278 
    279 	mutex_enter(&dm_target_mutex);
    280 
    281 	TAILQ_FOREACH(dm_target, &dm_target_list, dm_target_next) {
    282 		prop_array_t ver;
    283 		prop_dictionary_t target_dict;
    284 		int i;
    285 
    286 		target_dict = prop_dictionary_create();
    287 		ver = prop_array_create();
    288 		prop_dictionary_set_string(target_dict, DM_TARGETS_NAME,
    289 		    dm_target->name);
    290 
    291 		for (i = 0; i < 3; i++)
    292 			prop_array_add_uint32(ver, dm_target->version[i]);
    293 
    294 		prop_dictionary_set(target_dict, DM_TARGETS_VERSION, ver);
    295 		prop_array_add(target_array, target_dict);
    296 
    297 		prop_object_release(ver);
    298 		prop_object_release(target_dict);
    299 	}
    300 
    301 	mutex_exit(&dm_target_mutex);
    302 
    303 	return target_array;
    304 }
    305 
    306 /*
    307  * Initialize dm_target subsystem.
    308  */
    309 int
    310 dm_target_init(void)
    311 {
    312 	dm_target_t *dmt;
    313 
    314 	mutex_init(&dm_target_mutex, MUTEX_DEFAULT, IPL_NONE);
    315 
    316 	dmt = dm_target_alloc("linear");
    317 	dmt->version[0] = 1;
    318 	dmt->version[1] = 0;
    319 	dmt->version[2] = 2;
    320 	dmt->init = &dm_target_linear_init;
    321 	dmt->table = &dm_target_linear_table;
    322 	dmt->strategy = &dm_target_linear_strategy;
    323 	dmt->sync = &dm_target_linear_sync;
    324 	dmt->destroy = &dm_target_linear_destroy;
    325 	//dmt->upcall = &dm_target_linear_upcall;
    326 	dmt->secsize = &dm_target_linear_secsize;
    327 	if (dm_target_insert(dmt))
    328 		printf("Failed to insert linear\n");
    329 
    330 	dmt = dm_target_alloc("striped");
    331 	dmt->version[0] = 1;
    332 	dmt->version[1] = 0;
    333 	dmt->version[2] = 3;
    334 	dmt->init = &dm_target_stripe_init;
    335 	dmt->info = &dm_target_stripe_info;
    336 	dmt->table = &dm_target_stripe_table;
    337 	dmt->strategy = &dm_target_stripe_strategy;
    338 	dmt->sync = &dm_target_stripe_sync;
    339 	dmt->destroy = &dm_target_stripe_destroy;
    340 	//dmt->upcall = &dm_target_stripe_upcall;
    341 	dmt->secsize = &dm_target_stripe_secsize;
    342 	if (dm_target_insert(dmt))
    343 		printf("Failed to insert striped\n");
    344 
    345 	dmt = dm_target_alloc("error");
    346 	dmt->version[0] = 1;
    347 	dmt->version[1] = 0;
    348 	dmt->version[2] = 0;
    349 	dmt->init = &dm_target_error_init;
    350 	dmt->strategy = &dm_target_error_strategy;
    351 	dmt->destroy = &dm_target_error_destroy;
    352 	//dmt->upcall = &dm_target_error_upcall;
    353 	if (dm_target_insert(dmt))
    354 		printf("Failed to insert error\n");
    355 
    356 	dmt = dm_target_alloc("zero");
    357 	dmt->version[0] = 1;
    358 	dmt->version[1] = 0;
    359 	dmt->version[2] = 0;
    360 	dmt->init = &dm_target_zero_init;
    361 	dmt->strategy = &dm_target_zero_strategy;
    362 	dmt->destroy = &dm_target_zero_destroy;
    363 	//dmt->upcall = &dm_target_zero_upcall;
    364 	if (dm_target_insert(dmt))
    365 		printf("Failed to insert zero\n");
    366 #if 0
    367 	dmt = dm_target_alloc("delay");
    368 	dmt->version[0] = 1;
    369 	dmt->version[1] = 0;
    370 	dmt->version[2] = 0;
    371 	dmt->init = &dm_target_delay_init;
    372 	dmt->info = &dm_target_delay_info;
    373 	dmt->table = &dm_target_delay_table;
    374 	dmt->strategy = &dm_target_delay_strategy;
    375 	dmt->sync = &dm_target_delay_sync;
    376 	dmt->destroy = &dm_target_delay_destroy;
    377 	//dmt->upcall = &dm_target_delay_upcall;
    378 	dmt->secsize = &dm_target_delay_secsize;
    379 	if (dm_target_insert(dmt))
    380 		printf("Failed to insert delay\n");
    381 	dm_target_delay_pool_create();
    382 
    383 	dmt = dm_target_alloc("flakey");
    384 	dmt->version[0] = 1;
    385 	dmt->version[1] = 0;
    386 	dmt->version[2] = 0;
    387 	dmt->init = &dm_target_flakey_init;
    388 	dmt->table = &dm_target_flakey_table;
    389 	dmt->strategy = &dm_target_flakey_strategy;
    390 	dmt->sync = &dm_target_flakey_sync;
    391 	dmt->destroy = &dm_target_flakey_destroy;
    392 	//dmt->upcall = &dm_target_flakey_upcall;
    393 	dmt->secsize = &dm_target_flakey_secsize;
    394 	if (dm_target_insert(dmt))
    395 		printf("Failed to insert flakey\n");
    396 #endif
    397 	return 0;
    398 }
    399