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  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /*
  27  * The pool configuration repository is stored in /etc/zfs/zpool.cache as a
  28  * single packed nvlist.  While it would be nice to just read in this
  29  * file from userland, this wouldn't work from a local zone.  So we have to have
  30  * a zpool ioctl to return the complete configuration for all pools.  In the
  31  * global zone, this will be identical to reading the file and unpacking it in
  32  * userland.
  33  */
  34
  35 #include <errno.h>
  36 #include <sys/stat.h>
  37 #include <fcntl.h>
  38 #include <stddef.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41 #include <libintl.h>
  42 #include <libuutil.h>
  43
  44 #include "libzfs_impl.h"
  45
  46 typedef struct config_node {
  47         char            *cn_name;
  48         nvlist_t        *cn_config;
  49         uu_avl_node_t   cn_avl;
  50 } config_node_t;
  51
  52 /* ARGSUSED */
  53 static int
  54 config_node_compare(const void *a, const void *b, void *unused)
  55 {
  56         int ret;
  57
  58         const config_node_t *ca = (config_node_t *)a;
  59         const config_node_t *cb = (config_node_t *)b;
  60
  61         ret = strcmp(ca->cn_name, cb->cn_name);
  62
  63         if (ret < 0)
  64                 return (-1);
  65         else if (ret > 0)
  66                 return (1);
  67         else
  68                 return (0);
  69 }
  70
  71 void
  72 namespace_clear(libzfs_handle_t *hdl)
  73 {
  74         if (hdl->libzfs_ns_avl) {
  75                 config_node_t *cn;
  76                 void *cookie = NULL;
  77
  78                 while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl,
  79                     &cookie)) != NULL) {
  80                         nvlist_free(cn->cn_config);
  81                         free(cn->cn_name);
  82                         free(cn);
  83                 }
  84
  85                 uu_avl_destroy(hdl->libzfs_ns_avl);
  86                 hdl->libzfs_ns_avl = NULL;
  87         }
  88
  89         if (hdl->libzfs_ns_avlpool) {
  90                 uu_avl_pool_destroy(hdl->libzfs_ns_avlpool);
  91                 hdl->libzfs_ns_avlpool = NULL;
  92         }
  93 }
  94
  95 /*
  96  * Loads the pool namespace, or re-loads it if the cache has changed.
  97  */
  98 static int
  99 namespace_reload(libzfs_handle_t *hdl)
 100 {
 101         nvlist_t *config;
 102         config_node_t *cn;
 103         nvpair_t *elem;
 104         zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
 105         void *cookie;
 106
 107         if (hdl->libzfs_ns_gen == 0) {
 108                 /*
 109                  * This is the first time we've accessed the configuration
 110                  * cache.  Initialize the AVL tree and then fall through to the
 111                  * common code.
 112                  */
 113                 if ((hdl->libzfs_ns_avlpool = uu_avl_pool_create("config_pool",
 114                     sizeof (config_node_t),
 115                     offsetof(config_node_t, cn_avl),
 116                     config_node_compare, UU_DEFAULT)) == NULL)
 117                         return (no_memory(hdl));
 118
 119                 if ((hdl->libzfs_ns_avl = uu_avl_create(hdl->libzfs_ns_avlpool,
 120                     NULL, UU_DEFAULT)) == NULL)
 121                         return (no_memory(hdl));
 122         }
 123
 124         if (zcmd_alloc_dst_nvlist(hdl, &zc, 0) != 0)
 125                 return (-1);
 126
 127         for (;;) {
 128                 zc.zc_cookie = hdl->libzfs_ns_gen;
 129                 if (ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_CONFIGS, &zc) != 0) {
 130                         switch (errno) {
 131                         case EEXIST:
 132                                 /*
 133                                  * The namespace hasn't changed.
 134                                  */
 135                                 zcmd_free_nvlists(&zc);
 136                                 return (0);
 137
 138                         case ENOMEM:
 139                                 if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
 140                                         zcmd_free_nvlists(&zc);
 141                                         return (-1);
 142                                 }
 143                                 break;
 144
 145                         default:
 146                                 zcmd_free_nvlists(&zc);
 147                                 return (zfs_standard_error(hdl, errno,
 148                                     dgettext(TEXT_DOMAIN, "failed to read "
 149                                     "pool configuration")));
 150                         }
 151                 } else {
 152                         hdl->libzfs_ns_gen = zc.zc_cookie;
 153                         break;
 154                 }
 155         }
 156
 157         if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) {
 158                 zcmd_free_nvlists(&zc);
 159                 return (-1);
 160         }
 161
 162         zcmd_free_nvlists(&zc);
 163
 164         /*
 165          * Clear out any existing configuration information.
 166          */
 167         cookie = NULL;
 168         while ((cn = uu_avl_teardown(hdl->libzfs_ns_avl, &cookie)) != NULL) {
 169                 nvlist_free(cn->cn_config);
 170                 free(cn->cn_name);
 171                 free(cn);
 172         }
 173
 174         elem = NULL;
 175         while ((elem = nvlist_next_nvpair(config, elem)) != NULL) {
 176                 nvlist_t *child;
 177                 uu_avl_index_t where;
 178
 179                 if ((cn = zfs_alloc(hdl, sizeof (config_node_t))) == NULL) {
 180                         nvlist_free(config);
 181                         return (-1);
 182                 }
 183
 184                 if ((cn->cn_name = zfs_strdup(hdl,
 185                     nvpair_name(elem))) == NULL) {
 186                         free(cn);
 187                         nvlist_free(config);
 188                         return (-1);
 189                 }
 190
 191                 verify(nvpair_value_nvlist(elem, &child) == 0);
 192                 if (nvlist_dup(child, &cn->cn_config, 0) != 0) {
 193                         free(cn->cn_name);
 194                         free(cn);
 195                         nvlist_free(config);
 196                         return (no_memory(hdl));
 197                 }
 198                 verify(uu_avl_find(hdl->libzfs_ns_avl, cn, NULL, &where)
 199                     == NULL);
 200
 201                 uu_avl_insert(hdl->libzfs_ns_avl, cn, where);
 202         }
 203
 204         nvlist_free(config);
 205         return (0);
 206 }
 207
 208 /*
 209  * Retrieve the configuration for the given pool.  The configuration is a nvlist
 210  * describing the vdevs, as well as the statistics associated with each one.
 211  */
 212 nvlist_t *
 213 zpool_get_config(zpool_handle_t *zhp, nvlist_t **oldconfig)
 214 {
 215         if (oldconfig)
 216                 *oldconfig = zhp->zpool_old_config;
 217         return (zhp->zpool_config);
 218 }
 219
 220 /*
 221  * Refresh the vdev statistics associated with the given pool.  This is used in
 222  * iostat to show configuration changes and determine the delta from the last
 223  * time the function was called.  This function can fail, in case the pool has
 224  * been destroyed.
 225  */
 226 int
 227 zpool_refresh_stats(zpool_handle_t *zhp, boolean_t *missing)
 228 {
 229         zfs_cmd_t zc = { "\0", "\0", "\0", "\0", 0 };
 230         int error;
 231         nvlist_t *config;
 232         libzfs_handle_t *hdl = zhp->zpool_hdl;
 233
 234         *missing = B_FALSE;
 235         (void) strcpy(zc.zc_name, zhp->zpool_name);
 236
 237         if (zhp->zpool_config_size == 0)
 238                 zhp->zpool_config_size = 1 << 16;
 239
 240         if (zcmd_alloc_dst_nvlist(hdl, &zc, zhp->zpool_config_size) != 0)
 241                 return (-1);
 242
 243         for (;;) {
 244                 if (ioctl(zhp->zpool_hdl->libzfs_fd, ZFS_IOC_POOL_STATS,
 245                     &zc) == 0) {
 246                         /*
 247                          * The real error is returned in the zc_cookie field.
 248                          */
 249                         error = zc.zc_cookie;
 250                         break;
 251                 }
 252
 253                 if (errno == ENOMEM) {
 254                         if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
 255                                 zcmd_free_nvlists(&zc);
 256                                 return (-1);
 257                         }
 258                 } else {
 259                         zcmd_free_nvlists(&zc);
 260                         if (errno == ENOENT || errno == EINVAL)
 261                                 *missing = B_TRUE;
 262                         zhp->zpool_state = POOL_STATE_UNAVAIL;
 263                         return (0);
 264                 }
 265         }
 266
 267         if (zcmd_read_dst_nvlist(hdl, &zc, &config) != 0) {
 268                 zcmd_free_nvlists(&zc);
 269                 return (-1);
 270         }
 271
 272         zcmd_free_nvlists(&zc);
 273
 274         zhp->zpool_config_size = zc.zc_nvlist_dst_size;
 275
 276         if (zhp->zpool_config != NULL) {
 277                 uint64_t oldtxg, newtxg;
 278
 279                 verify(nvlist_lookup_uint64(zhp->zpool_config,
 280                     ZPOOL_CONFIG_POOL_TXG, &oldtxg) == 0);
 281                 verify(nvlist_lookup_uint64(config,
 282                     ZPOOL_CONFIG_POOL_TXG, &newtxg) == 0);
 283
 284                 if (zhp->zpool_old_config != NULL)
 285                         nvlist_free(zhp->zpool_old_config);
 286
 287                 if (oldtxg != newtxg) {
 288                         nvlist_free(zhp->zpool_config);
 289                         zhp->zpool_old_config = NULL;
 290                 } else {
 291                         zhp->zpool_old_config = zhp->zpool_config;
 292                 }
 293         }
 294
 295         zhp->zpool_config = config;
 296         if (error)
 297                 zhp->zpool_state = POOL_STATE_UNAVAIL;
 298         else
 299                 zhp->zpool_state = POOL_STATE_ACTIVE;
 300
 301         return (0);
 302 }
 303
 304 /*
 305  * Iterate over all pools in the system.
 306  */
 307 int
 308 zpool_iter(libzfs_handle_t *hdl, zpool_iter_f func, void *data)
 309 {
 310         config_node_t *cn;
 311         zpool_handle_t *zhp;
 312         int ret;
 313
 314         /*
 315          * If someone makes a recursive call to zpool_iter(), we want to avoid
 316          * refreshing the namespace because that will invalidate the parent
 317          * context.  We allow recursive calls, but simply re-use the same
 318          * namespace AVL tree.
 319          */
 320         if (!hdl->libzfs_pool_iter && namespace_reload(hdl) != 0)
 321                 return (-1);
 322
 323         hdl->libzfs_pool_iter++;
 324         for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
 325             cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
 326
 327                 if (zpool_open_silent(hdl, cn->cn_name, &zhp) != 0) {
 328                         hdl->libzfs_pool_iter--;
 329                         return (-1);
 330                 }
 331
 332                 if (zhp == NULL)
 333                         continue;
 334
 335                 if ((ret = func(zhp, data)) != 0) {
 336                         hdl->libzfs_pool_iter--;
 337                         return (ret);
 338                 }
 339         }
 340         hdl->libzfs_pool_iter--;
 341
 342         return (0);
 343 }
 344
 345 /*
 346  * Iterate over root datasets, calling the given function for each.  The zfs
 347  * handle passed each time must be explicitly closed by the callback.
 348  */
 349 int
 350 zfs_iter_root(libzfs_handle_t *hdl, zfs_iter_f func, void *data)
 351 {
 352         config_node_t *cn;
 353         zfs_handle_t *zhp;
 354         int ret;
 355
 356         if (namespace_reload(hdl) != 0)
 357                 return (-1);
 358
 359         for (cn = uu_avl_first(hdl->libzfs_ns_avl); cn != NULL;
 360             cn = uu_avl_next(hdl->libzfs_ns_avl, cn)) {
 361
 362                 if ((zhp = make_dataset_handle(hdl, cn->cn_name)) == NULL)
 363                         continue;
 364
 365                 if ((ret = func(zhp, data)) != 0)
 366                         return (ret);
 367         }
 368
 369         return (0);
 370 }