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  * Copyright 2016 Nexenta Systems, Inc.
  31  */
  32
  33 /*
  34  * The pool configuration repository is stored in /etc/zfs/zpool.cache as a
  35  * single packed nvlist.  While it would be nice to just read in this
  36  * file from userland, this wouldn't work from a local zone.  So we have to have
  37  * a zpool ioctl to return the complete configuration for all pools.  In the
  38  * global zone, this will be identical to reading the file and unpacking it in
  39  * userland.
  40  */
  41
  42 #include <errno.h>
  43 #include <sys/stat.h>
  44 #include <fcntl.h>
  45 #include <stddef.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48 #include <libintl.h>
  49 #include <libuutil.h>
  50
  51 #include "libzfs_impl.h"
  52
  53 typedef struct config_node {
  54         char            *cn_name;
  55         nvlist_t        *cn_config;
  56         uu_avl_node_t   cn_avl;
  57 } config_node_t;
  58
  59 /* ARGSUSED */
  60 static int
  61 config_node_compare(const void *a, const void *b, void *unused)
  62 {
  63         int ret;
  64
  65         const config_node_t *ca = (config_node_t *)a;
  66         const config_node_t *cb = (config_node_t *)b;
  67
  68         ret = strcmp(ca->cn_name, cb->cn_name);
  69
  70         if (ret < 0)
  71                 return (-1);
  72         else if (ret > 0)
  73                 return (1);
  74         else
  75                 return (0);
  76 }
  77
  78 void
  79 namespace_clear(libzfs_handle_t *hdl)
  80 {
  81         if (hdl->libzfs_ns_avl) {
  82                 config_node_t *cn;
  83                 void *cookie = NULL;
  84
  85                 while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl,
  86                     &cookie)) != NULL) {
  87                         nvlist_free(cn->cn_config);
  88                         free(cn->cn_name);
  89                         free(cn);
  90                 }
  91
  92                 uu_avl_destroy(hdl->libzfs_ns_avl);
  93                 hdl->libzfs_ns_avl = NULL;
  94         }
  95
  96         if (hdl->libzfs_ns_avlpool) {
  97                 uu_avl_pool_destroy(hdl->libzfs_ns_avlpool);
  98                 hdl->libzfs_ns_avlpool = NULL;
  99         }
 100 }
 101
 102 /*
 103  * Loads the pool namespace, or re-loads it if the cache has changed.
 104  */
 105 static int
 106 namespace_reload(libzfs_handle_t *hdl)
 107 {
 108         nvlist_t *config;
 109         config_node_t *cn;
 110         nvpair_t *elem;
 111         zfs_cmd_t zc = {"\0"};
 112         void *cookie;
 113
 114         if (hdl->libzfs_ns_gen == 0) {
 115                 /*
 116                  * This is the first time we've accessed the configuration
 117                  * cache.  Initialize the AVL tree and then fall through to the
 118                  * common code.
 119                  */
 120                 if ((hdl->libzfs_ns_avlpool = uu_avl_pool_create("config_pool",
 121                     sizeof (config_node_t),
 122                     offsetof(config_node_t, cn_avl),
 123                     config_node_compare, UU_DEFAULT)) == NULL)
 124                         return (no_memory(hdl));
 125
 126                 if ((hdl->libzfs_ns_avl = uu_avl_create(hdl->libzfs_ns_avlpool,
 127                     NULL, UU_DEFAULT)) == NULL)
 128                         return (no_memory(hdl));
 129         }
 130
 131         if (zcmd_alloc_dst_nvlist(hdl, &zc, 0) != 0)
 132                 return (-1);
 133
 134         for (;;) {
 135                 zc.zc_cookie = hdl->libzfs_ns_gen;
 136                 if (ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_CONFIGS, &zc) != 0) {
 137                         switch (errno) {
 138                         case EEXIST:
 139                                 /*
 140                                  * The namespace hasn't changed.
 141                                  */
 142                                 zcmd_free_nvlists(&zc);
 143                                 return (0);
 144
 145                         case ENOMEM:
 146                                 if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
 147                                         zcmd_free_nvlists(&zc);
 148                                         return (-1);
 149                                 }
 150                                 break;
 151
 152                         default:
 153                                 zcmd_free_nvlists(&zc);
 154                                 return (zfs_standard_error(hdl, errno,
 155                                     dgettext(TEXT_DOMAIN, "failed to read "
 156                                     "pool configuration")));
 157                         }
 158                 } else {
 159                         hdl->libzfs_ns_gen = zc.zc_cookie;
 160                         break;
 161                 }
 162         }
 163
 164         if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) {
 165                 zcmd_free_nvlists(&zc);
 166                 return (-1);
 167         }
 168
 169         zcmd_free_nvlists(&zc);
 170
 171         /*
 172          * Clear out any existing configuration information.
 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         elem = NULL;
 182         while ((elem = nvlist_next_nvpair(config, elem)) != NULL) {
 183                 nvlist_t *child;
 184                 uu_avl_index_t where;
 185
 186                 if ((cn = zfs_alloc(hdl, sizeof (config_node_t))) == NULL) {
 187                         nvlist_free(config);
 188                         return (-1);
 189                 }
 190
 191                 if ((cn->cn_name = zfs_strdup(hdl,
 192                     nvpair_name(elem))) == NULL) {
 193                         free(cn);
 194                         nvlist_free(config);
 195                         return (-1);
 196                 }
 197
 198                 verify(nvpair_value_nvlist(elem, &child) == 0);
 199                 if (nvlist_dup(child, &cn->cn_config, 0) != 0) {
 200                         free(cn->cn_name);
 201                         free(cn);
 202                         nvlist_free(config);
 203                         return (no_memory(hdl));
 204                 }
 205                 verify(uu_avl_find(hdl->libzfs_ns_avl, cn, NULL, &where)
 206                     == NULL);
 207
 208                 uu_avl_insert(hdl->libzfs_ns_avl, cn, where);
 209         }
 210
 211         nvlist_free(config);
 212         return (0);
 213 }
 214
 215 /*
 216  * Retrieve the configuration for the given pool. The configuration is an nvlist
 217  * describing the vdevs, as well as the statistics associated with each one.
 218  */
 219 nvlist_t *
 220 zpool_get_config(zpool_handle_t *zhp, nvlist_t **oldconfig)
 221 {
 222         if (oldconfig)
 223                 *oldconfig = zhp->zpool_old_config;
 224         return (zhp->zpool_config);
 225 }
 226
 227 /*
 228  * Retrieves a list of enabled features and their refcounts and caches it in
 229  * the pool handle.
 230  */
 231 nvlist_t *
 232 zpool_get_features(zpool_handle_t *zhp)
 233 {
 234         nvlist_t *config, *features;
 235
 236         config = zpool_get_config(zhp, NULL);
 237
 238         if (config == NULL || !nvlist_exists(config,
 239             ZPOOL_CONFIG_FEATURE_STATS)) {
 240                 int error;
 241                 boolean_t missing = B_FALSE;
 242
 243                 error = zpool_refresh_stats(zhp, &missing);
 244
 245                 if (error != 0 || missing)
 246                         return (NULL);
 247
 248                 config = zpool_get_config(zhp, NULL);
 249         }
 250
 251         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
 252             &features) != 0)
 253                 return (NULL);
 254
 255         return (features);
 256 }
 257
 258 /*
 259  * Refresh the vdev statistics associated with the given pool.  This is used in
 260  * iostat to show configuration changes and determine the delta from the last
 261  * time the function was called.  This function can fail, in case the pool has
 262  * been destroyed.
 263  */
 264 int
 265 zpool_refresh_stats(zpool_handle_t *zhp, boolean_t *missing)
 266 {
 267         zfs_cmd_t zc = {"\0"};
 268         int error;
 269         nvlist_t *config;
 270         libzfs_handle_t *hdl = zhp->zpool_hdl;
 271
 272         *missing = B_FALSE;
 273         (void) strcpy(zc.zc_name, zhp->zpool_name);
 274
 275         if (zhp->zpool_config_size == 0)
 276                 zhp->zpool_config_size = 1 << 16;
 277
 278         if (zcmd_alloc_dst_nvlist(hdl, &zc, zhp->zpool_config_size) != 0)
 279                 return (-1);
 280
 281         for (;;) {
 282                 if (ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_POOL_STATS,
 283                     &zc) == 0) {
 284                         /*
 285                          * The real error is returned in the zc_cookie field.
 286                          */
 287                         error = zc.zc_cookie;
 288                         break;
 289                 }
 290
 291                 if (errno == ENOMEM) {
 292                         if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
 293                                 zcmd_free_nvlists(&zc);
 294                                 return (-1);
 295                         }
 296                 } else {
 297                         zcmd_free_nvlists(&zc);
 298                         if (errno == ENOENT || errno == EINVAL)
 299                                 *missing = B_TRUE;
 300                         zhp->zpool_state = POOL_STATE_UNAVAIL;
 301                         return (0);
 302                 }
 303         }
 304
 305         if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) {
 306                 zcmd_free_nvlists(&zc);
 307                 return (-1);
 308         }
 309
 310         zcmd_free_nvlists(&zc);
 311
 312         zhp->zpool_config_size = zc.zc_nvlist_dst_size;
 313
 314         if (zhp->zpool_config != NULL) {
 315                 nvlist_free(zhp->zpool_old_config);
 316
 317                 zhp->zpool_old_config = zhp->zpool_config;
 318         }
 319
 320         zhp->zpool_config = config;
 321         if (error)
 322                 zhp->zpool_state = POOL_STATE_UNAVAIL;
 323         else
 324                 zhp->zpool_state = POOL_STATE_ACTIVE;
 325
 326         return (0);
 327 }
 328
 329 /*
 330  * The following environment variables are undocumented
 331  * and should be used for testing purposes only:
 332  *
 333  * __ZFS_POOL_EXCLUDE - don't iterate over the pools it lists
 334  * __ZFS_POOL_RESTRICT - iterate only over the pools it lists
 335  *
 336  * This function returns B_TRUE if the pool should be skipped
 337  * during iteration.
 338  */
 339 boolean_t
 340 zpool_skip_pool(const char *poolname)
 341 {
 342         static boolean_t initialized = B_FALSE;
 343         static const char *exclude = NULL;
 344         static const char *restricted = NULL;
 345
 346         const char *cur, *end;
 347         int len;
 348         int namelen = strlen(poolname);
 349
 350         if (!initialized) {
 351                 initialized = B_TRUE;
 352                 exclude = getenv("__ZFS_POOL_EXCLUDE");
 353                 restricted = getenv("__ZFS_POOL_RESTRICT");
 354         }
 355
 356         if (exclude != NULL) {
 357                 cur = exclude;
 358                 do {
 359                         end = strchr(cur, ' ');
 360                         len = (NULL == end) ? strlen(cur) : (end - cur);
 361                         if (len == namelen && 0 == strncmp(cur, poolname, len))
 362                                 return (B_TRUE);
 363                         cur += (len + 1);
 364                 } while (NULL != end);
 365         }
 366
 367         if (NULL == restricted)
 368                 return (B_FALSE);
 369
 370         cur = restricted;
 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 (zpool_skip_pool(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 (zpool_skip_pool(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 }