module/zfs/spa_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 #include <sys/spa.h>
  28 #include <sys/spa_impl.h>
  29 #include <sys/nvpair.h>
  30 #include <sys/uio.h>
  31 #include <sys/fs/zfs.h>
  32 #include <sys/vdev_impl.h>
  33 #include <sys/zfs_ioctl.h>
  34 #include <sys/utsname.h>
  35 #include <sys/systeminfo.h>
  36 #include <sys/sunddi.h>
  37 #ifdef _KERNEL
  38 #include <sys/kobj.h>
  39 #include <sys/zone.h>
  40 #endif
  41
  42 /*
  43  * Pool configuration repository.
  44  *
  45  * Pool configuration is stored as a packed nvlist on the filesystem.  By
  46  * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot
  47  * (when the ZFS module is loaded).  Pools can also have the 'cachefile'
  48  * property set that allows them to be stored in an alternate location until
  49  * the control of external software.
  50  *
  51  * For each cache file, we have a single nvlist which holds all the
  52  * configuration information.  When the module loads, we read this information
  53  * from /etc/zfs/zpool.cache and populate the SPA namespace.  This namespace is
  54  * maintained independently in spa.c.  Whenever the namespace is modified, or
  55  * the configuration of a pool is changed, we call spa_config_sync(), which
  56  * walks through all the active pools and writes the configuration to disk.
  57  */
  58
  59 static uint64_t spa_config_generation = 1;
  60
  61 /*
  62  * This can be overridden in userland to preserve an alternate namespace for
  63  * userland pools when doing testing.
  64  */
  65 const char *spa_config_path = ZPOOL_CACHE;
  66
  67 /*
  68  * Called when the module is first loaded, this routine loads the configuration
  69  * file into the SPA namespace.  It does not actually open or load the pools; it
  70  * only populates the namespace.
  71  */
  72 void
  73 spa_config_load(void)
  74 {
  75         void *buf = NULL;
  76         nvlist_t *nvlist, *child;
  77         nvpair_t *nvpair;
  78         spa_t *spa;
  79         char *pathname;
  80         struct _buf *file;
  81         uint64_t fsize;
  82
  83         /*
  84          * Open the configuration file.
  85          */
  86         pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
  87
  88         (void) snprintf(pathname, MAXPATHLEN, "%s%s",
  89             (rootdir != NULL) ? "./" : "", spa_config_path);
  90
  91         file = kobj_open_file(pathname);
  92
  93         kmem_free(pathname, MAXPATHLEN);
  94
  95         if (file == (struct _buf *)-1)
  96                 return;
  97
  98         if (kobj_get_filesize(file, &fsize) != 0)
  99                 goto out;
 100
 101         buf = kmem_alloc(fsize, KM_SLEEP);
 102
 103         /*
 104          * Read the nvlist from the file.
 105          */
 106         if (kobj_read_file(file, buf, fsize, 0) < 0)
 107                 goto out;
 108
 109         /*
 110          * Unpack the nvlist.
 111          */
 112         if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
 113                 goto out;
 114
 115         /*
 116          * Iterate over all elements in the nvlist, creating a new spa_t for
 117          * each one with the specified configuration.
 118          */
 119         mutex_enter(&spa_namespace_lock);
 120         nvpair = NULL;
 121         while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
 122
 123                 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)
 124                         continue;
 125
 126                 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0);
 127
 128                 if (spa_lookup(nvpair_name(nvpair)) != NULL)
 129                         continue;
 130                 spa = spa_add(nvpair_name(nvpair), NULL);
 131
 132                 /*
 133                  * We blindly duplicate the configuration here.  If it's
 134                  * invalid, we will catch it when the pool is first opened.
 135                  */
 136                 VERIFY(nvlist_dup(child, &spa->spa_config, 0) == 0);
 137         }
 138         mutex_exit(&spa_namespace_lock);
 139
 140         nvlist_free(nvlist);
 141
 142 out:
 143         if (buf != NULL)
 144                 kmem_free(buf, fsize);
 145
 146         kobj_close_file(file);
 147 }
 148
 149 static void
 150 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
 151 {
 152         size_t buflen;
 153         char *buf;
 154         vnode_t *vp;
 155         int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
 156         char *temp;
 157
 158         /*
 159          * If the nvlist is empty (NULL), then remove the old cachefile.
 160          */
 161         if (nvl == NULL) {
 162                 (void) vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
 163                 return;
 164         }
 165
 166         /*
 167          * Pack the configuration into a buffer.
 168          */
 169         VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0);
 170
 171         buf = kmem_alloc(buflen, KM_SLEEP);
 172         temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
 173
 174         VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR,
 175             KM_SLEEP) == 0);
 176
 177         /*
 178          * Write the configuration to disk.  We need to do the traditional
 179          * 'write to temporary file, sync, move over original' to make sure we
 180          * always have a consistent view of the data.
 181          */
 182         (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);
 183
 184         if (vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) == 0) {
 185                 if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
 186                     0, RLIM64_INFINITY, kcred, NULL) == 0 &&
 187                     VOP_FSYNC(vp, FSYNC, kcred, NULL) == 0) {
 188                         (void) vn_rename(temp, dp->scd_path, UIO_SYSSPACE);
 189                 }
 190                 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
 191                 VN_RELE(vp);
 192         }
 193
 194         (void) vn_remove(temp, UIO_SYSSPACE, RMFILE);
 195
 196         kmem_free(buf, buflen);
 197         kmem_free(temp, MAXPATHLEN);
 198 }
 199
 200 /*
 201  * Synchronize pool configuration to disk.  This must be called with the
 202  * namespace lock held.
 203  */
 204 void
 205 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
 206 {
 207         spa_config_dirent_t *dp, *tdp;
 208         nvlist_t *nvl;
 209
 210         ASSERT(MUTEX_HELD(&spa_namespace_lock));
 211
 212         if (rootdir == NULL || !(spa_mode_global & FWRITE))
 213                 return;
 214
 215         /*
 216          * Iterate over all cachefiles for the pool, past or present.  When the
 217          * cachefile is changed, the new one is pushed onto this list, allowing
 218          * us to update previous cachefiles that no longer contain this pool.
 219          */
 220         for (dp = list_head(&target->spa_config_list); dp != NULL;
 221             dp = list_next(&target->spa_config_list, dp)) {
 222                 spa_t *spa = NULL;
 223                 if (dp->scd_path == NULL)
 224                         continue;
 225
 226                 /*
 227                  * Iterate over all pools, adding any matching pools to 'nvl'.
 228                  */
 229                 nvl = NULL;
 230                 while ((spa = spa_next(spa)) != NULL) {
 231                         if (spa == target && removing)
 232                                 continue;
 233
 234                         mutex_enter(&spa->spa_props_lock);
 235                         tdp = list_head(&spa->spa_config_list);
 236                         if (spa->spa_config == NULL ||
 237                             tdp->scd_path == NULL ||
 238                             strcmp(tdp->scd_path, dp->scd_path) != 0) {
 239                                 mutex_exit(&spa->spa_props_lock);
 240                                 continue;
 241                         }
 242
 243                         if (nvl == NULL)
 244                                 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME,
 245                                     KM_SLEEP) == 0);
 246
 247                         VERIFY(nvlist_add_nvlist(nvl, spa->spa_name,
 248                             spa->spa_config) == 0);
 249                         mutex_exit(&spa->spa_props_lock);
 250                 }
 251
 252                 spa_config_write(dp, nvl);
 253                 nvlist_free(nvl);
 254         }
 255
 256         /*
 257          * Remove any config entries older than the current one.
 258          */
 259         dp = list_head(&target->spa_config_list);
 260         while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
 261                 list_remove(&target->spa_config_list, tdp);
 262                 if (tdp->scd_path != NULL)
 263                         spa_strfree(tdp->scd_path);
 264                 kmem_free(tdp, sizeof (spa_config_dirent_t));
 265         }
 266
 267         spa_config_generation++;
 268
 269         if (postsysevent)
 270                 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC);
 271 }
 272
 273 /*
 274  * Sigh.  Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
 275  * and we don't want to allow the local zone to see all the pools anyway.
 276  * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
 277  * information for all pool visible within the zone.
 278  */
 279 nvlist_t *
 280 spa_all_configs(uint64_t *generation)
 281 {
 282         nvlist_t *pools;
 283         spa_t *spa = NULL;
 284
 285         if (*generation == spa_config_generation)
 286                 return (NULL);
 287
 288         VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 289
 290         mutex_enter(&spa_namespace_lock);
 291         while ((spa = spa_next(spa)) != NULL) {
 292                 if (INGLOBALZONE(curproc) ||
 293                     zone_dataset_visible(spa_name(spa), NULL)) {
 294                         mutex_enter(&spa->spa_props_lock);
 295                         VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
 296                             spa->spa_config) == 0);
 297                         mutex_exit(&spa->spa_props_lock);
 298                 }
 299         }
 300         *generation = spa_config_generation;
 301         mutex_exit(&spa_namespace_lock);
 302
 303         return (pools);
 304 }
 305
 306 void
 307 spa_config_set(spa_t *spa, nvlist_t *config)
 308 {
 309         mutex_enter(&spa->spa_props_lock);
 310         if (spa->spa_config != NULL)
 311                 nvlist_free(spa->spa_config);
 312         spa->spa_config = config;
 313         mutex_exit(&spa->spa_props_lock);
 314 }
 315
 316 /*
 317  * Generate the pool's configuration based on the current in-core state.
 318  * We infer whether to generate a complete config or just one top-level config
 319  * based on whether vd is the root vdev.
 320  */
 321 nvlist_t *
 322 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 323 {
 324         nvlist_t *config, *nvroot;
 325         vdev_t *rvd = spa->spa_root_vdev;
 326         unsigned long hostid = 0;
 327         boolean_t locked = B_FALSE;
 328
 329         if (vd == NULL) {
 330                 vd = rvd;
 331                 locked = B_TRUE;
 332                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
 333         }
 334
 335         ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
 336             (SCL_CONFIG | SCL_STATE));
 337
 338         /*
 339          * If txg is -1, report the current value of spa->spa_config_txg.
 340          */
 341         if (txg == -1ULL)
 342                 txg = spa->spa_config_txg;
 343
 344         VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 345
 346         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
 347             spa_version(spa)) == 0);
 348         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
 349             spa_name(spa)) == 0);
 350         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
 351             spa_state(spa)) == 0);
 352         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
 353             txg) == 0);
 354         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 355             spa_guid(spa)) == 0);
 356 #ifdef  _KERNEL
 357         hostid = zone_get_hostid(NULL);
 358 #else   /* _KERNEL */
 359         /*
 360          * We're emulating the system's hostid in userland, so we can't use
 361          * zone_get_hostid().
 362          */
 363         (void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
 364 #endif  /* _KERNEL */
 365         if (hostid != 0) {
 366                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
 367                     hostid) == 0);
 368         }
 369         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
 370             utsname.nodename) == 0);
 371
 372         if (vd != rvd) {
 373                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
 374                     vd->vdev_top->vdev_guid) == 0);
 375                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
 376                     vd->vdev_guid) == 0);
 377                 if (vd->vdev_isspare)
 378                         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,
 379                             1ULL) == 0);
 380                 if (vd->vdev_islog)
 381                         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,
 382                             1ULL) == 0);
 383                 vd = vd->vdev_top;              /* label contains top config */
 384         }
 385
 386         nvroot = vdev_config_generate(spa, vd, getstats, B_FALSE, B_FALSE);
 387         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
 388         nvlist_free(nvroot);
 389
 390         if (locked)
 391                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
 392
 393         return (config);
 394 }
 395
 396 /*
 397  * Update all disk labels, generate a fresh config based on the current
 398  * in-core state, and sync the global config cache (do not sync the config
 399  * cache if this is a booting rootpool).
 400  */
 401 void
 402 spa_config_update(spa_t *spa, int what)
 403 {
 404         vdev_t *rvd = spa->spa_root_vdev;
 405         uint64_t txg;
 406         int c;
 407
 408         ASSERT(MUTEX_HELD(&spa_namespace_lock));
 409
 410         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
 411         txg = spa_last_synced_txg(spa) + 1;
 412         if (what == SPA_CONFIG_UPDATE_POOL) {
 413                 vdev_config_dirty(rvd);
 414         } else {
 415                 /*
 416                  * If we have top-level vdevs that were added but have
 417                  * not yet been prepared for allocation, do that now.
 418                  * (It's safe now because the config cache is up to date,
 419                  * so it will be able to translate the new DVAs.)
 420                  * See comments in spa_vdev_add() for full details.
 421                  */
 422                 for (c = 0; c < rvd->vdev_children; c++) {
 423                         vdev_t *tvd = rvd->vdev_child[c];
 424                         if (tvd->vdev_ms_array == 0)
 425                                 vdev_metaslab_set_size(tvd);
 426                         vdev_expand(tvd, txg);
 427                 }
 428         }
 429         spa_config_exit(spa, SCL_ALL, FTAG);
 430
 431         /*
 432          * Wait for the mosconfig to be regenerated and synced.
 433          */
 434         txg_wait_synced(spa->spa_dsl_pool, txg);
 435
 436         /*
 437          * Update the global config cache to reflect the new mosconfig.
 438          */
 439         if (!spa->spa_is_root)
 440                 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
 441
 442         if (what == SPA_CONFIG_UPDATE_POOL)
 443                 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
 444 }