1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * Copyright (c) 2012 by Delphix. All rights reserved. 29 * Copyright (c) 2015 by Syneto S.R.L. All rights reserved. 30 */ 31 32 /* 33 * The pool configuration repository is stored in /etc/zfs/zpool.cache as a 34 * single packed nvlist. While it would be nice to just read in this 35 * file from userland, this wouldn't work from a local zone. So we have to have 36 * a zpool ioctl to return the complete configuration for all pools. In the 37 * global zone, this will be identical to reading the file and unpacking it in 38 * userland. 39 */ 40 41 #include <errno.h> 42 #include <sys/stat.h> 43 #include <fcntl.h> 44 #include <stddef.h> 45 #include <string.h> 46 #include <unistd.h> 47 #include <libintl.h> 48 #include <libuutil.h> 49 50 #include "libzfs_impl.h" 51 52 typedef struct config_node { 53 char *cn_name; 54 nvlist_t *cn_config; 55 uu_avl_node_t cn_avl; 56 } config_node_t; 57 58 /* ARGSUSED */ 59 static int 60 config_node_compare(const void *a, const void *b, void *unused) 61 { 62 int ret; 63 64 const config_node_t *ca = (config_node_t *)a; 65 const config_node_t *cb = (config_node_t *)b; 66 67 ret = strcmp(ca->cn_name, cb->cn_name); 68 69 if (ret < 0) 70 return (-1); 71 else if (ret > 0) 72 return (1); 73 else 74 return (0); 75 } 76 77 void 78 namespace_clear(libzfs_handle_t *hdl) 79 { 80 if (hdl->libzfs_ns_avl) { 81 config_node_t *cn; 82 void *cookie = NULL; 83 84 while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl, 85 &cookie)) != NULL) { 86 nvlist_free(cn->cn_config); 87 free(cn->cn_name); 88 free(cn); 89 } 90 91 uu_avl_destroy(hdl->libzfs_ns_avl); 92 hdl->libzfs_ns_avl = NULL; 93 } 94 95 if (hdl->libzfs_ns_avlpool) { 96 uu_avl_pool_destroy(hdl->libzfs_ns_avlpool); 97 hdl->libzfs_ns_avlpool = NULL; 98 } 99 } 100 101 /* 102 * Loads the pool namespace, or re-loads it if the cache has changed. 103 */ 104 static int 105 namespace_reload(libzfs_handle_t *hdl) 106 { 107 nvlist_t *config; 108 config_node_t *cn; 109 nvpair_t *elem; 110 zfs_cmd_t zc = { 0 }; 111 void *cookie; 112 113 if (hdl->libzfs_ns_gen == 0) { 114 /* 115 * This is the first time we've accessed the configuration 116 * cache. Initialize the AVL tree and then fall through to the 117 * common code. 118 */ 119 if ((hdl->libzfs_ns_avlpool = uu_avl_pool_create("config_pool", 120 sizeof (config_node_t), 121 offsetof(config_node_t, cn_avl), 122 config_node_compare, UU_DEFAULT)) == NULL) 123 return (no_memory(hdl)); 124 125 if ((hdl->libzfs_ns_avl = uu_avl_create(hdl->libzfs_ns_avlpool, 126 NULL, UU_DEFAULT)) == NULL) 127 return (no_memory(hdl)); 128 } 129 130 if (zcmd_alloc_dst_nvlist(hdl, &zc, 0) != 0) 131 return (-1); 132 133 for (;;) { 134 zc.zc_cookie = hdl->libzfs_ns_gen; 135 if (ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_CONFIGS, &zc) != 0) { 136 switch (errno) { 137 case EEXIST: 138 /* 139 * The namespace hasn't changed. 140 */ 141 zcmd_free_nvlists(&zc); 142 return (0); 143 144 case ENOMEM: 145 if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) { 146 zcmd_free_nvlists(&zc); 147 return (-1); 148 } 149 break; 150 151 default: 152 zcmd_free_nvlists(&zc); 153 return (zfs_standard_error(hdl, errno, 154 dgettext(TEXT_DOMAIN, "failed to read " 155 "pool configuration"))); 156 } 157 } else { 158 hdl->libzfs_ns_gen = zc.zc_cookie; 159 break; 160 } 161 } 162 163 if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) { 164 zcmd_free_nvlists(&zc); 165 return (-1); 166 } 167 168 zcmd_free_nvlists(&zc); 169 170 /* 171 * Clear out any existing configuration information. 172 */ 173 cookie = NULL; 174 while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl, &cookie)) != NULL) { 175 nvlist_free(cn->cn_config); 176 free(cn->cn_name); 177 free(cn); 178 } 179 180 elem = NULL; 181 while ((elem = nvlist_next_nvpair(config, elem)) != NULL) { 182 nvlist_t *child; 183 uu_avl_index_t where; 184 185 if ((cn = zfs_alloc(hdl, sizeof (config_node_t))) == NULL) { 186 nvlist_free(config); 187 return (-1); 188 } 189 190 if ((cn->cn_name = zfs_strdup(hdl, 191 nvpair_name(elem))) == NULL) { 192 free(cn); 193 nvlist_free(config); 194 return (-1); 195 } 196 197 verify(nvpair_value_nvlist(elem, &child) == 0); 198 if (nvlist_dup(child, &cn->cn_config, 0) != 0) { 199 free(cn->cn_name); 200 free(cn); 201 nvlist_free(config); 202 return (no_memory(hdl)); 203 } 204 verify(uu_avl_find(hdl->libzfs_ns_avl, cn, NULL, &where) 205 == NULL); 206 207 uu_avl_insert(hdl->libzfs_ns_avl, cn, where); 208 } 209 210 nvlist_free(config); 211 return (0); 212 } 213 214 /* 215 * Retrieve the configuration for the given pool. The configuration is a nvlist 216 * describing the vdevs, as well as the statistics associated with each one. 217 */ 218 nvlist_t * 219 zpool_get_config(zpool_handle_t *zhp, nvlist_t **oldconfig) 220 { 221 if (oldconfig) 222 *oldconfig = zhp->zpool_old_config; 223 return (zhp->zpool_config); 224 } 225 226 /* 227 * Retrieves a list of enabled features and their refcounts and caches it in 228 * the pool handle. 229 */ 230 nvlist_t * 231 zpool_get_features(zpool_handle_t *zhp) 232 { 233 nvlist_t *config, *features; 234 235 config = zpool_get_config(zhp, NULL); 236 237 if (config == NULL || !nvlist_exists(config, 238 ZPOOL_CONFIG_FEATURE_STATS)) { 239 int error; 240 boolean_t missing = B_FALSE; 241 242 error = zpool_refresh_stats(zhp, &missing); 243 244 if (error != 0 || missing) 245 return (NULL); 246 247 config = zpool_get_config(zhp, NULL); 248 } 249 250 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS, 251 &features) != 0) 252 return (NULL); 253 254 return (features); 255 } 256 257 /* 258 * Refresh the vdev statistics associated with the given pool. This is used in 259 * iostat to show configuration changes and determine the delta from the last 260 * time the function was called. This function can fail, in case the pool has 261 * been destroyed. 262 */ 263 int 264 zpool_refresh_stats(zpool_handle_t *zhp, boolean_t *missing) 265 { 266 zfs_cmd_t zc = { 0 }; 267 int error; 268 nvlist_t *config; 269 libzfs_handle_t *hdl = zhp->zpool_hdl; 270 271 *missing = B_FALSE; 272 (void) strcpy(zc.zc_name, zhp->zpool_name); 273 274 if (zhp->zpool_config_size == 0) 275 zhp->zpool_config_size = 1 << 16; 276 277 if (zcmd_alloc_dst_nvlist(hdl, &zc, zhp->zpool_config_size) != 0) 278 return (-1); 279 280 for (;;) { 281 if (ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_POOL_STATS, 282 &zc) == 0) { 283 /* 284 * The real error is returned in the zc_cookie field. 285 */ 286 error = zc.zc_cookie; 287 break; 288 } 289 290 if (errno == ENOMEM) { 291 if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) { 292 zcmd_free_nvlists(&zc); 293 return (-1); 294 } 295 } else { 296 zcmd_free_nvlists(&zc); 297 if (errno == ENOENT || errno == EINVAL) 298 *missing = B_TRUE; 299 zhp->zpool_state = POOL_STATE_UNAVAIL; 300 return (0); 301 } 302 } 303 304 if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) { 305 zcmd_free_nvlists(&zc); 306 return (-1); 307 } 308 309 zcmd_free_nvlists(&zc); 310 311 zhp->zpool_config_size = zc.zc_nvlist_dst_size; 312 313 if (zhp->zpool_config != NULL) { 314 uint64_t oldtxg, newtxg; 315 316 verify(nvlist_lookup_uint64(zhp->zpool_config, 317 ZPOOL_CONFIG_POOL_TXG, &oldtxg) == 0); 318 verify(nvlist_lookup_uint64(config, 319 ZPOOL_CONFIG_POOL_TXG, &newtxg) == 0); 320 321 if (zhp->zpool_old_config != NULL) 322 nvlist_free(zhp->zpool_old_config); 323 324 if (oldtxg != newtxg) { 325 nvlist_free(zhp->zpool_config); 326 zhp->zpool_old_config = NULL; 327 } else { 328 zhp->zpool_old_config = zhp->zpool_config; 329 } 330 } 331 332 zhp->zpool_config = config; 333 if (error) 334 zhp->zpool_state = POOL_STATE_UNAVAIL; 335 else 336 zhp->zpool_state = POOL_STATE_ACTIVE; 337 338 return (0); 339 } 340 341 /* 342 * If the __ZFS_POOL_RESTRICT environment variable is set we only iterate over 343 * pools it lists. 344 * 345 * This is an undocumented feature for use during testing only. 346 * 347 * This function returns B_TRUE if the pool should be skipped 348 * during iteration. 349 */ 350 static boolean_t 351 check_restricted(const char *poolname) 352 { 353 static boolean_t initialized = B_FALSE; 354 static char *restricted = NULL; 355 356 const char *cur, *end; 357 int len, namelen; 358 359 if (!initialized) { 360 initialized = B_TRUE; 361 restricted = getenv("__ZFS_POOL_RESTRICT"); 362 } 363 364 if (NULL == restricted) 365 return (B_FALSE); 366 367 cur = restricted; 368 namelen = strlen(poolname); 369 do { 370 end = strchr(cur, ' '); 371 len = (NULL == end) ? strlen(cur) : (end - cur); 372 373 if (len == namelen && 0 == strncmp(cur, poolname, len)) { 374 return (B_FALSE); 375 } 376 377 cur += (len + 1); 378 } while (NULL != end); 379 380 return (B_TRUE); 381 } 382 383 /* 384 * Iterate over all pools in the system. 385 */ 386 int 387 zpool_iter(libzfs_handle_t *hdl, zpool_iter_f func, void *data) 388 { 389 config_node_t *cn; 390 zpool_handle_t *zhp; 391 int ret; 392 393 /* 394 * If someone makes a recursive call to zpool_iter(), we want to avoid 395 * refreshing the namespace because that will invalidate the parent 396 * context. We allow recursive calls, but simply re-use the same 397 * namespace AVL tree. 398 */ 399 if (!hdl->libzfs_pool_iter && namespace_reload(hdl) != 0) 400 return (-1); 401 402 hdl->libzfs_pool_iter++; 403 for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL; 404 cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) { 405 406 if (check_restricted(cn->cn_name)) 407 continue; 408 409 if (zpool_open_silent(hdl, cn->cn_name, &zhp) != 0) { 410 hdl->libzfs_pool_iter--; 411 return (-1); 412 } 413 414 if (zhp == NULL) 415 continue; 416 417 if ((ret = func(zhp, data)) != 0) { 418 hdl->libzfs_pool_iter--; 419 return (ret); 420 } 421 } 422 hdl->libzfs_pool_iter--; 423 424 return (0); 425 } 426 427 /* 428 * Iterate over root datasets, calling the given function for each. The zfs 429 * handle passed each time must be explicitly closed by the callback. 430 */ 431 int 432 zfs_iter_root(libzfs_handle_t *hdl, zfs_iter_f func, void *data) 433 { 434 config_node_t *cn; 435 zfs_handle_t *zhp; 436 int ret; 437 438 if (namespace_reload(hdl) != 0) 439 return (-1); 440 441 for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL; 442 cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) { 443 444 if (check_restricted(cn->cn_name)) 445 continue; 446 447 if ((zhp = make_dataset_handle(hdl, cn->cn_name)) == NULL) 448 continue; 449 450 if ((ret = func(zhp, data)) != 0) 451 return (ret); 452 } 453 454 return (0); 455 } 456