zfs/lib/libzpool/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 2008 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 #endif
  40
  41 /*
  42  * Pool configuration repository.
  43  *
  44  * Pool configuration is stored as a packed nvlist on the filesystem.  By
  45  * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot
  46  * (when the ZFS module is loaded).  Pools can also have the 'cachefile'
  47  * property set that allows them to be stored in an alternate location until
  48  * the control of external software.
  49  *
  50  * For each cache file, we have a single nvlist which holds all the
  51  * configuration information.  When the module loads, we read this information
  52  * from /etc/zfs/zpool.cache and populate the SPA namespace.  This namespace is
  53  * maintained independently in spa.c.  Whenever the namespace is modified, or
  54  * the configuration of a pool is changed, we call spa_config_sync(), which
  55  * walks through all the active pools and writes the configuration to disk.
  56  */
  57
  58 static uint64_t spa_config_generation = 1;
  59
  60 /*
  61  * This can be overridden in userland to preserve an alternate namespace for
  62  * userland pools when doing testing.
  63  */
  64 const char *spa_config_path = ZPOOL_CACHE;
  65
  66 /*
  67  * Called when the module is first loaded, this routine loads the configuration
  68  * file into the SPA namespace.  It does not actually open or load the pools; it
  69  * only populates the namespace.
  70  */
  71 void
  72 spa_config_load(void)
  73 {
  74         void *buf = NULL;
  75         nvlist_t *nvlist, *child;
  76         nvpair_t *nvpair;
  77         spa_t *spa;
  78         char *pathname;
  79         struct _buf *file;
  80         uint64_t fsize;
  81
  82         /*
  83          * Open the configuration file.
  84          */
  85         pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
  86
  87         (void) snprintf(pathname, MAXPATHLEN, "%s%s",
  88             (rootdir != NULL) ? "./" : "", spa_config_path);
  89
  90         file = kobj_open_file(pathname);
  91
  92         kmem_free(pathname, MAXPATHLEN);
  93
  94         if (file == (struct _buf *)-1)
  95                 return;
  96
  97         if (kobj_get_filesize(file, &fsize) != 0)
  98                 goto out;
  99
 100         buf = kmem_alloc(fsize, KM_SLEEP);
 101
 102         /*
 103          * Read the nvlist from the file.
 104          */
 105         if (kobj_read_file(file, buf, fsize, 0) < 0)
 106                 goto out;
 107
 108         /*
 109          * Unpack the nvlist.
 110          */
 111         if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
 112                 goto out;
 113
 114         /*
 115          * Iterate over all elements in the nvlist, creating a new spa_t for
 116          * each one with the specified configuration.
 117          */
 118         mutex_enter(&spa_namespace_lock);
 119         nvpair = NULL;
 120         while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
 121
 122                 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)
 123                         continue;
 124
 125                 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0);
 126
 127                 if (spa_lookup(nvpair_name(nvpair)) != NULL)
 128                         continue;
 129                 spa = spa_add(nvpair_name(nvpair), NULL);
 130
 131                 /*
 132                  * We blindly duplicate the configuration here.  If it's
 133                  * invalid, we will catch it when the pool is first opened.
 134                  */
 135                 VERIFY(nvlist_dup(child, &spa->spa_config, 0) == 0);
 136         }
 137         mutex_exit(&spa_namespace_lock);
 138
 139         nvlist_free(nvlist);
 140
 141 out:
 142         if (buf != NULL)
 143                 kmem_free(buf, fsize);
 144
 145         kobj_close_file(file);
 146 }
 147
 148 static void
 149 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
 150 {
 151         size_t buflen;
 152         char *buf;
 153         vnode_t *vp;
 154         int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
 155         char *temp;
 156
 157         /*
 158          * If the nvlist is empty (NULL), then remove the old cachefile.
 159          */
 160         if (nvl == NULL) {
 161                 (void) vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
 162                 return;
 163         }
 164
 165         /*
 166          * Pack the configuration into a buffer.
 167          */
 168         VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0);
 169
 170         buf = kmem_alloc(buflen, KM_SLEEP);
 171         temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
 172
 173         VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR,
 174             KM_SLEEP) == 0);
 175
 176         /*
 177          * Write the configuration to disk.  We need to do the traditional
 178          * 'write to temporary file, sync, move over original' to make sure we
 179          * always have a consistent view of the data.
 180          */
 181         (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);
 182
 183         if (vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) == 0) {
 184                 if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
 185                     0, RLIM64_INFINITY, kcred, NULL) == 0 &&
 186                     VOP_FSYNC(vp, FSYNC, kcred, NULL) == 0) {
 187                         (void) vn_rename(temp, dp->scd_path, UIO_SYSSPACE);
 188                 }
 189                 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
 190                 VN_RELE(vp);
 191         }
 192
 193         (void) vn_remove(temp, UIO_SYSSPACE, RMFILE);
 194
 195         kmem_free(buf, buflen);
 196         kmem_free(temp, MAXPATHLEN);
 197 }
 198
 199 /*
 200  * Synchronize pool configuration to disk.  This must be called with the
 201  * namespace lock held.
 202  */
 203 void
 204 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
 205 {
 206         spa_config_dirent_t *dp, *tdp;
 207         nvlist_t *nvl;
 208
 209         ASSERT(MUTEX_HELD(&spa_namespace_lock));
 210
 211         /*
 212          * Iterate over all cachefiles for the pool, past or present.  When the
 213          * cachefile is changed, the new one is pushed onto this list, allowing
 214          * us to update previous cachefiles that no longer contain this pool.
 215          */
 216         for (dp = list_head(&target->spa_config_list); dp != NULL;
 217             dp = list_next(&target->spa_config_list, dp)) {
 218                 spa_t *spa = NULL;
 219                 if (dp->scd_path == NULL)
 220                         continue;
 221
 222                 /*
 223                  * Iterate over all pools, adding any matching pools to 'nvl'.
 224                  */
 225                 nvl = NULL;
 226                 while ((spa = spa_next(spa)) != NULL) {
 227                         if (spa == target && removing)
 228                                 continue;
 229
 230                         mutex_enter(&spa->spa_props_lock);
 231                         tdp = list_head(&spa->spa_config_list);
 232                         if (spa->spa_config == NULL ||
 233                             tdp->scd_path == NULL ||
 234                             strcmp(tdp->scd_path, dp->scd_path) != 0) {
 235                                 mutex_exit(&spa->spa_props_lock);
 236                                 continue;
 237                         }
 238
 239                         if (nvl == NULL)
 240                                 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME,
 241                                     KM_SLEEP) == 0);
 242
 243                         VERIFY(nvlist_add_nvlist(nvl, spa->spa_name,
 244                             spa->spa_config) == 0);
 245                         mutex_exit(&spa->spa_props_lock);
 246                 }
 247
 248                 spa_config_write(dp, nvl);
 249                 nvlist_free(nvl);
 250         }
 251
 252         /*
 253          * Remove any config entries older than the current one.
 254          */
 255         dp = list_head(&target->spa_config_list);
 256         while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
 257                 list_remove(&target->spa_config_list, tdp);
 258                 if (tdp->scd_path != NULL)
 259                         spa_strfree(tdp->scd_path);
 260                 kmem_free(tdp, sizeof (spa_config_dirent_t));
 261         }
 262
 263         spa_config_generation++;
 264
 265         if (postsysevent)
 266                 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC);
 267 }
 268
 269 /*
 270  * Sigh.  Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
 271  * and we don't want to allow the local zone to see all the pools anyway.
 272  * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
 273  * information for all pool visible within the zone.
 274  */
 275 nvlist_t *
 276 spa_all_configs(uint64_t *generation)
 277 {
 278         nvlist_t *pools;
 279         spa_t *spa = NULL;
 280
 281         if (*generation == spa_config_generation)
 282                 return (NULL);
 283
 284         VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 285
 286         mutex_enter(&spa_namespace_lock);
 287         while ((spa = spa_next(spa)) != NULL) {
 288                 if (INGLOBALZONE(curproc) ||
 289                     zone_dataset_visible(spa_name(spa), NULL)) {
 290                         mutex_enter(&spa->spa_props_lock);
 291                         VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
 292                             spa->spa_config) == 0);
 293                         mutex_exit(&spa->spa_props_lock);
 294                 }
 295         }
 296         *generation = spa_config_generation;
 297         mutex_exit(&spa_namespace_lock);
 298
 299         return (pools);
 300 }
 301
 302 void
 303 spa_config_set(spa_t *spa, nvlist_t *config)
 304 {
 305         mutex_enter(&spa->spa_props_lock);
 306         if (spa->spa_config != NULL)
 307                 nvlist_free(spa->spa_config);
 308         spa->spa_config = config;
 309         mutex_exit(&spa->spa_props_lock);
 310 }
 311
 312 /*
 313  * Generate the pool's configuration based on the current in-core state.
 314  * We infer whether to generate a complete config or just one top-level config
 315  * based on whether vd is the root vdev.
 316  */
 317 nvlist_t *
 318 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 319 {
 320         nvlist_t *config, *nvroot;
 321         vdev_t *rvd = spa->spa_root_vdev;
 322         unsigned long hostid = 0;
 323         boolean_t locked = B_FALSE;
 324
 325         if (vd == NULL) {
 326                 vd = rvd;
 327                 locked = B_TRUE;
 328                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
 329         }
 330
 331         ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
 332             (SCL_CONFIG | SCL_STATE));
 333
 334         /*
 335          * If txg is -1, report the current value of spa->spa_config_txg.
 336          */
 337         if (txg == -1ULL)
 338                 txg = spa->spa_config_txg;
 339
 340         VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);
 341
 342         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
 343             spa_version(spa)) == 0);
 344         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
 345             spa_name(spa)) == 0);
 346         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
 347             spa_state(spa)) == 0);
 348         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
 349             txg) == 0);
 350         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 351             spa_guid(spa)) == 0);
 352         (void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
 353         if (hostid != 0) {
 354                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
 355                     hostid) == 0);
 356         }
 357         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
 358             utsname.nodename) == 0);
 359
 360         if (vd != rvd) {
 361                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
 362                     vd->vdev_top->vdev_guid) == 0);
 363                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
 364                     vd->vdev_guid) == 0);
 365                 if (vd->vdev_isspare)
 366                         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,
 367                             1ULL) == 0);
 368                 if (vd->vdev_islog)
 369                         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,
 370                             1ULL) == 0);
 371                 vd = vd->vdev_top;              /* label contains top config */
 372         }
 373
 374         nvroot = vdev_config_generate(spa, vd, getstats, B_FALSE, B_FALSE);
 375         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
 376         nvlist_free(nvroot);
 377
 378         if (locked)
 379                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
 380
 381         return (config);
 382 }
 383
 384 /*
 385  * For a pool that's not currently a booting rootpool, update all disk labels,
 386  * generate a fresh config based on the current in-core state, and sync the
 387  * global config cache.
 388  */
 389 void
 390 spa_config_update(spa_t *spa, int what)
 391 {
 392         spa_config_update_common(spa, what, FALSE);
 393 }
 394
 395 /*
 396  * Update all disk labels, generate a fresh config based on the current
 397  * in-core state, and sync the global config cache (do not sync the config
 398  * cache if this is a booting rootpool).
 399  */
 400 void
 401 spa_config_update_common(spa_t *spa, int what, boolean_t isroot)
 402 {
 403         vdev_t *rvd = spa->spa_root_vdev;
 404         uint64_t txg;
 405         int c;
 406
 407         ASSERT(MUTEX_HELD(&spa_namespace_lock));
 408
 409         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
 410         txg = spa_last_synced_txg(spa) + 1;
 411         if (what == SPA_CONFIG_UPDATE_POOL) {
 412                 vdev_config_dirty(rvd);
 413         } else {
 414                 /*
 415                  * If we have top-level vdevs that were added but have
 416                  * not yet been prepared for allocation, do that now.
 417                  * (It's safe now because the config cache is up to date,
 418                  * so it will be able to translate the new DVAs.)
 419                  * See comments in spa_vdev_add() for full details.
 420                  */
 421                 for (c = 0; c < rvd->vdev_children; c++) {
 422                         vdev_t *tvd = rvd->vdev_child[c];
 423                         if (tvd->vdev_ms_array == 0) {
 424                                 vdev_init(tvd, txg);
 425                                 vdev_config_dirty(tvd);
 426                         }
 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 (!isroot)
 440                 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
 441
 442         if (what == SPA_CONFIG_UPDATE_POOL)
 443                 spa_config_update_common(spa, SPA_CONFIG_UPDATE_VDEVS, isroot);
 444 }