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 2015 Nexenta Systems, Inc.  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, and recreate
 172          * the AVL tree.
 173          */
 174         cookie = NULL;
 175         while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl, &cookie)) != NULL) {
 176                 nvlist_free(cn->cn_config);
 177                 free(cn->cn_name);
 178                 free(cn);
 179         }
 180 
 181         uu_avl_recreate(hdl->libzfs_ns_avl);
 182 
 183         elem = NULL;
 184         while ((elem = nvlist_next_nvpair(config, elem)) != NULL) {
 185                 nvlist_t *child;
 186                 uu_avl_index_t where;
 187 
 188                 if ((cn = zfs_alloc(hdl, sizeof (config_node_t))) == NULL) {
 189                         nvlist_free(config);
 190                         return (-1);
 191                 }
 192 
 193                 if ((cn->cn_name = zfs_strdup(hdl,
 194                     nvpair_name(elem))) == NULL) {
 195                         free(cn);
 196                         nvlist_free(config);
 197                         return (-1);
 198                 }
 199 
 200                 verify(nvpair_value_nvlist(elem, &child) == 0);
 201                 if (nvlist_dup(child, &cn->cn_config, 0) != 0) {
 202                         free(cn->cn_name);
 203                         free(cn);
 204                         nvlist_free(config);
 205                         return (no_memory(hdl));
 206                 }
 207                 verify(uu_avl_find(hdl->libzfs_ns_avl, cn, NULL, &where)
 208                     == NULL);
 209 
 210                 uu_avl_insert(hdl->libzfs_ns_avl, cn, where);
 211         }
 212 
 213         nvlist_free(config);
 214         return (0);
 215 }
 216 
 217 /*
 218  * Retrieve the configuration for the given pool.  The configuration is a nvlist
 219  * describing the vdevs, as well as the statistics associated with each one.
 220  */
 221 nvlist_t *
 222 zpool_get_config(zpool_handle_t *zhp, nvlist_t **oldconfig)
 223 {
 224         if (oldconfig)
 225                 *oldconfig = zhp->zpool_old_config;
 226         return (zhp->zpool_config);
 227 }
 228 
 229 /*
 230  * Retrieves a list of enabled features and their refcounts and caches it in
 231  * the pool handle.
 232  */
 233 nvlist_t *
 234 zpool_get_features(zpool_handle_t *zhp)
 235 {
 236         nvlist_t *config, *features;
 237 
 238         config = zpool_get_config(zhp, NULL);
 239 
 240         if (config == NULL || !nvlist_exists(config,
 241             ZPOOL_CONFIG_FEATURE_STATS)) {
 242                 int error;
 243                 boolean_t missing = B_FALSE;
 244 
 245                 error = zpool_refresh_stats(zhp, &missing);
 246 
 247                 if (error != 0 || missing)
 248                         return (NULL);
 249 
 250                 config = zpool_get_config(zhp, NULL);
 251         }
 252 
 253         verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
 254             &features) == 0);
 255 
 256         return (features);
 257 }
 258 
 259 /*
 260  * Refresh the vdev statistics associated with the given pool.  This is used in
 261  * iostat to show configuration changes and determine the delta from the last
 262  * time the function was called.  This function can fail, in case the pool has
 263  * been destroyed.
 264  */
 265 int
 266 zpool_refresh_stats(zpool_handle_t *zhp, boolean_t *missing)
 267 {
 268         zfs_cmd_t zc = { 0 };
 269         int error;
 270         nvlist_t *config;
 271         libzfs_handle_t *hdl = zhp->zpool_hdl;
 272 
 273         *missing = B_FALSE;
 274         (void) strcpy(zc.zc_name, zhp->zpool_name);
 275 
 276         if (zhp->zpool_config_size == 0)
 277                 zhp->zpool_config_size = 1 << 16;
 278 
 279         if (zcmd_alloc_dst_nvlist(hdl, &zc, zhp->zpool_config_size) != 0)
 280                 return (-1);
 281 
 282         for (;;) {
 283                 if (ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_POOL_STATS,
 284                     &zc) == 0) {
 285                         /*
 286                          * The real error is returned in the zc_cookie field.
 287                          */
 288                         error = zc.zc_cookie;
 289                         break;
 290                 }
 291 
 292                 if (errno == ENOMEM) {
 293                         if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
 294                                 zcmd_free_nvlists(&zc);
 295                                 return (-1);
 296                         }
 297                 } else {
 298                         zcmd_free_nvlists(&zc);
 299                         if (errno == ENOENT || errno == EINVAL)
 300                                 *missing = B_TRUE;
 301                         zhp->zpool_state = POOL_STATE_UNAVAIL;
 302                         return (0);
 303                 }
 304         }
 305 
 306         if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) {
 307                 zcmd_free_nvlists(&zc);
 308                 return (-1);
 309         }
 310 
 311         zcmd_free_nvlists(&zc);
 312 
 313         zhp->zpool_config_size = zc.zc_nvlist_dst_size;
 314 
 315         if (zhp->zpool_config != NULL) {
 316                 uint64_t oldtxg, newtxg;
 317 
 318                 verify(nvlist_lookup_uint64(zhp->zpool_config,
 319                     ZPOOL_CONFIG_POOL_TXG, &oldtxg) == 0);
 320                 verify(nvlist_lookup_uint64(config,
 321                     ZPOOL_CONFIG_POOL_TXG, &newtxg) == 0);
 322 
 323                 if (zhp->zpool_old_config != NULL)
 324                         nvlist_free(zhp->zpool_old_config);
 325 
 326                 if (oldtxg != newtxg) {
 327                         nvlist_free(zhp->zpool_config);
 328                         zhp->zpool_old_config = NULL;
 329                 } else {
 330                         zhp->zpool_old_config = zhp->zpool_config;
 331                 }
 332         }
 333 
 334         zhp->zpool_config = config;
 335         if (error)
 336                 zhp->zpool_state = POOL_STATE_UNAVAIL;
 337         else
 338                 zhp->zpool_state = POOL_STATE_ACTIVE;
 339 
 340         return (0);
 341 }
 342 
 343 /*
 344  * If the __ZFS_POOL_RESTRICT environment variable is set we only iterate over
 345  * pools it lists.
 346  *
 347  * This is an undocumented feature for use during testing only.
 348  *
 349  * This function returns B_TRUE if the pool should be skipped
 350  * during iteration.
 351  */
 352 static boolean_t
 353 check_restricted(const char *poolname)
 354 {
 355         static boolean_t initialized = B_FALSE;
 356         static char *restricted = NULL;
 357 
 358         const char *cur, *end;
 359         int len, namelen;
 360 
 361         if (!initialized) {
 362                 initialized = B_TRUE;
 363                 restricted = getenv("__ZFS_POOL_RESTRICT");
 364         }
 365 
 366         if (NULL == restricted)
 367                 return (B_FALSE);
 368 
 369         cur = restricted;
 370         namelen = strlen(poolname);
 371         do {
 372                 end = strchr(cur, ' ');
 373                 len = (NULL == end) ? strlen(cur) : (end - cur);
 374 
 375                 if (len == namelen && 0 == strncmp(cur, poolname, len)) {
 376                         return (B_FALSE);
 377                 }
 378 
 379                 cur += (len + 1);
 380         } while (NULL != end);
 381 
 382         return (B_TRUE);
 383 }
 384 
 385 /*
 386  * Iterate over all pools in the system.
 387  */
 388 int
 389 zpool_iter(libzfs_handle_t *hdl, zpool_iter_f func, void *data)
 390 {
 391         config_node_t *cn;
 392         zpool_handle_t *zhp;
 393         int ret;
 394 
 395         /*
 396          * If someone makes a recursive call to zpool_iter(), we want to avoid
 397          * refreshing the namespace because that will invalidate the parent
 398          * context.  We allow recursive calls, but simply re-use the same
 399          * namespace AVL tree.
 400          */
 401         if (!hdl->libzfs_pool_iter && namespace_reload(hdl) != 0)
 402                 return (-1);
 403 
 404         hdl->libzfs_pool_iter++;
 405         for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
 406             cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
 407 
 408                 if (check_restricted(cn->cn_name))
 409                         continue;
 410 
 411                 if (zpool_open_silent(hdl, cn->cn_name, &zhp) != 0) {
 412                         hdl->libzfs_pool_iter--;
 413                         return (-1);
 414                 }
 415 
 416                 if (zhp == NULL)
 417                         continue;
 418 
 419                 if ((ret = func(zhp, data)) != 0) {
 420                         hdl->libzfs_pool_iter--;
 421                         return (ret);
 422                 }
 423         }
 424         hdl->libzfs_pool_iter--;
 425 
 426         return (0);
 427 }
 428 
 429 /*
 430  * Iterate over root datasets, calling the given function for each.  The zfs
 431  * handle passed each time must be explicitly closed by the callback.
 432  */
 433 int
 434 zfs_iter_root(libzfs_handle_t *hdl, zfs_iter_f func, void *data)
 435 {
 436         config_node_t *cn;
 437         zfs_handle_t *zhp;
 438         int ret;
 439 
 440         if (namespace_reload(hdl) != 0)
 441                 return (-1);
 442 
 443         for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
 444             cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
 445 
 446                 if (check_restricted(cn->cn_name))
 447                         continue;
 448 
 449                 if ((zhp = make_dataset_handle(hdl, cn->cn_name)) == NULL)
 450                         continue;
 451 
 452                 if ((ret = func(zhp, data)) != 0)
 453                         return (ret);
 454         }
 455 
 456         return (0);
 457 }