lib/libzfs/libzfs_config.c

   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 an 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                 nvlist_free(zhp->zpool_old_config);
 315
 316                 zhp->zpool_old_config = zhp->zpool_config;
 317         }
 318
 319         zhp->zpool_config = config;
 320         if (error)
 321                 zhp->zpool_state = POOL_STATE_UNAVAIL;
 322         else
 323                 zhp->zpool_state = POOL_STATE_ACTIVE;
 324
 325         return (0);
 326 }
 327
 328 /*
 329  * If the __ZFS_POOL_RESTRICT environment variable is set we only iterate over
 330  * pools it lists.
 331  *
 332  * This is an undocumented feature for use during testing only.
 333  *
 334  * This function returns B_TRUE if the pool should be skipped
 335  * during iteration.
 336  */
 337 static boolean_t
 338 check_restricted(const char *poolname)
 339 {
 340         static boolean_t initialized = B_FALSE;
 341         static char *restricted = NULL;
 342
 343         const char *cur, *end;
 344         int len, namelen;
 345
 346         if (!initialized) {
 347                 initialized = B_TRUE;
 348                 restricted = getenv("__ZFS_POOL_RESTRICT");
 349         }
 350
 351         if (NULL == restricted)
 352                 return (B_FALSE);
 353
 354         cur = restricted;
 355         namelen = strlen(poolname);
 356         do {
 357                 end = strchr(cur, ' ');
 358                 len = (NULL == end) ? strlen(cur) : (end - cur);
 359
 360                 if (len == namelen && 0 == strncmp(cur, poolname, len)) {
 361                         return (B_FALSE);
 362                 }
 363
 364                 cur += (len + 1);
 365         } while (NULL != end);
 366
 367         return (B_TRUE);
 368 }
 369
 370 /*
 371  * Iterate over all pools in the system.
 372  */
 373 int
 374 zpool_iter(libzfs_handle_t *hdl, zpool_iter_f func, void *data)
 375 {
 376         config_node_t *cn;
 377         zpool_handle_t *zhp;
 378         int ret;
 379
 380         /*
 381          * If someone makes a recursive call to zpool_iter(), we want to avoid
 382          * refreshing the namespace because that will invalidate the parent
 383          * context.  We allow recursive calls, but simply re-use the same
 384          * namespace AVL tree.
 385          */
 386         if (!hdl->libzfs_pool_iter && namespace_reload(hdl) != 0)
 387                 return (-1);
 388
 389         hdl->libzfs_pool_iter++;
 390         for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
 391             cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
 392
 393                 if (check_restricted(cn->cn_name))
 394                         continue;
 395
 396                 if (zpool_open_silent(hdl, cn->cn_name, &zhp) != 0) {
 397                         hdl->libzfs_pool_iter--;
 398                         return (-1);
 399                 }
 400
 401                 if (zhp == NULL)
 402                         continue;
 403
 404                 if ((ret = func(zhp, data)) != 0) {
 405                         hdl->libzfs_pool_iter--;
 406                         return (ret);
 407                 }
 408         }
 409         hdl->libzfs_pool_iter--;
 410
 411         return (0);
 412 }
 413
 414 /*
 415  * Iterate over root datasets, calling the given function for each.  The zfs
 416  * handle passed each time must be explicitly closed by the callback.
 417  */
 418 int
 419 zfs_iter_root(libzfs_handle_t *hdl, zfs_iter_f func, void *data)
 420 {
 421         config_node_t *cn;
 422         zfs_handle_t *zhp;
 423         int ret;
 424
 425         if (namespace_reload(hdl) != 0)
 426                 return (-1);
 427
 428         for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
 429             cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
 430
 431                 if (check_restricted(cn->cn_name))
 432                         continue;
 433
 434                 if ((zhp = make_dataset_handle(hdl, cn->cn_name)) == NULL)
 435                         continue;
 436
 437                 if ((ret = func(zhp, data)) != 0)
 438                         return (ret);
 439         }
 440
 441         return (0);
 442 }