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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25 * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
26 * Copyright 2017 Joyent, Inc.
27 */
28
29 #include <sys/spa.h>
30 #include <sys/file.h>
31 #include <sys/fm/fs/zfs.h>
32 #include <sys/spa_impl.h>
33 #include <sys/nvpair.h>
34 #include <sys/uio.h>
35 #include <sys/fs/zfs.h>
36 #include <sys/vdev_impl.h>
37 #include <sys/zfs_ioctl.h>
38 #include <sys/systeminfo.h>
39 #include <sys/sunddi.h>
40 #include <sys/zfeature.h>
41 #include <sys/zfs_file.h>
42 #ifdef _KERNEL
43 #include <sys/zone.h>
44 #endif
45
46 /*
47 * Pool configuration repository.
48 *
49 * Pool configuration is stored as a packed nvlist on the filesystem. By
50 * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot
51 * (when the ZFS module is loaded). Pools can also have the 'cachefile'
52 * property set that allows them to be stored in an alternate location until
53 * the control of external software.
54 *
55 * For each cache file, we have a single nvlist which holds all the
56 * configuration information. When the module loads, we read this information
57 * from /etc/zfs/zpool.cache and populate the SPA namespace. This namespace is
58 * maintained independently in spa.c. Whenever the namespace is modified, or
59 * the configuration of a pool is changed, we call spa_write_cachefile(), which
60 * walks through all the active pools and writes the configuration to disk.
61 */
62
63 static uint64_t spa_config_generation = 1;
64
65 /*
66 * This can be overridden in userland to preserve an alternate namespace for
67 * userland pools when doing testing.
68 */
69 char *spa_config_path = ZPOOL_CACHE;
70 int zfs_autoimport_disable = 1;
71
72 /*
73 * Called when the module is first loaded, this routine loads the configuration
74 * file into the SPA namespace. It does not actually open or load the pools; it
75 * only populates the namespace.
76 */
77 void
spa_config_load(void)78 spa_config_load(void)
79 {
80 void *buf = NULL;
81 nvlist_t *nvlist, *child;
82 nvpair_t *nvpair;
83 char *pathname;
84 zfs_file_t *fp;
85 zfs_file_attr_t zfa;
86 uint64_t fsize;
87 int err;
88
89 #ifdef _KERNEL
90 if (zfs_autoimport_disable)
91 return;
92 #endif
93
94 /*
95 * Open the configuration file.
96 */
97 pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
98
99 (void) snprintf(pathname, MAXPATHLEN, "%s", spa_config_path);
100
101 err = zfs_file_open(pathname, O_RDONLY, 0, &fp);
102
103 #ifdef __FreeBSD__
104 if (err)
105 err = zfs_file_open(ZPOOL_CACHE_BOOT, O_RDONLY, 0, &fp);
106 #endif
107 kmem_free(pathname, MAXPATHLEN);
108
109 if (err)
110 return;
111
112 if (zfs_file_getattr(fp, &zfa))
113 goto out;
114
115 fsize = zfa.zfa_size;
116 buf = kmem_alloc(fsize, KM_SLEEP);
117
118 /*
119 * Read the nvlist from the file.
120 */
121 if (zfs_file_read(fp, buf, fsize, NULL) < 0)
122 goto out;
123
124 /*
125 * Unpack the nvlist.
126 */
127 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
128 goto out;
129
130 /*
131 * Iterate over all elements in the nvlist, creating a new spa_t for
132 * each one with the specified configuration.
133 */
134 mutex_enter(&spa_namespace_lock);
135 nvpair = NULL;
136 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
137 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)
138 continue;
139
140 child = fnvpair_value_nvlist(nvpair);
141
142 if (spa_lookup(nvpair_name(nvpair)) != NULL)
143 continue;
144 (void) spa_add(nvpair_name(nvpair), child, NULL);
145 }
146 mutex_exit(&spa_namespace_lock);
147
148 nvlist_free(nvlist);
149
150 out:
151 if (buf != NULL)
152 kmem_free(buf, fsize);
153
154 zfs_file_close(fp);
155 }
156
157 static int
spa_config_remove(spa_config_dirent_t * dp)158 spa_config_remove(spa_config_dirent_t *dp)
159 {
160 int error = 0;
161
162 /*
163 * Remove the cache file. If zfs_file_unlink() in not supported by the
164 * platform fallback to truncating the file which is functionally
165 * equivalent.
166 */
167 error = zfs_file_unlink(dp->scd_path);
168 if (error == EOPNOTSUPP) {
169 int flags = O_RDWR | O_TRUNC;
170 zfs_file_t *fp;
171
172 error = zfs_file_open(dp->scd_path, flags, 0644, &fp);
173 if (error == 0) {
174 (void) zfs_file_fsync(fp, O_SYNC);
175 (void) zfs_file_close(fp);
176 }
177 }
178
179 return (error);
180 }
181
182 static int
spa_config_write(spa_config_dirent_t * dp,nvlist_t * nvl)183 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
184 {
185 size_t buflen;
186 char *buf;
187 int oflags = O_RDWR | O_TRUNC | O_CREAT | O_LARGEFILE;
188 char *temp;
189 int err;
190 zfs_file_t *fp;
191
192 /*
193 * If the nvlist is empty (NULL), then remove the old cachefile.
194 */
195 if (nvl == NULL) {
196 err = spa_config_remove(dp);
197 if (err == ENOENT)
198 err = 0;
199
200 return (err);
201 }
202
203 /*
204 * Pack the configuration into a buffer.
205 */
206 buf = fnvlist_pack(nvl, &buflen);
207 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
208
209 /*
210 * Write the configuration to disk. Due to the complexity involved
211 * in performing a rename and remove from within the kernel the file
212 * is instead truncated and overwritten in place. This way we always
213 * have a consistent view of the data or a zero length file.
214 */
215 err = zfs_file_open(dp->scd_path, oflags, 0644, &fp);
216 if (err == 0) {
217 err = zfs_file_write(fp, buf, buflen, NULL);
218 if (err == 0)
219 err = zfs_file_fsync(fp, O_SYNC);
220
221 zfs_file_close(fp);
222 if (err)
223 (void) spa_config_remove(dp);
224 }
225 fnvlist_pack_free(buf, buflen);
226 kmem_free(temp, MAXPATHLEN);
227 return (err);
228 }
229
230 /*
231 * Synchronize pool configuration to disk. This must be called with the
232 * namespace lock held. Synchronizing the pool cache is typically done after
233 * the configuration has been synced to the MOS. This exposes a window where
234 * the MOS config will have been updated but the cache file has not. If
235 * the system were to crash at that instant then the cached config may not
236 * contain the correct information to open the pool and an explicit import
237 * would be required.
238 */
239 void
spa_write_cachefile(spa_t * target,boolean_t removing,boolean_t postsysevent)240 spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent)
241 {
242 spa_config_dirent_t *dp, *tdp;
243 nvlist_t *nvl;
244 char *pool_name;
245 boolean_t ccw_failure;
246 int error = 0;
247
248 ASSERT(MUTEX_HELD(&spa_namespace_lock));
249
250 if (!(spa_mode_global & SPA_MODE_WRITE))
251 return;
252
253 /*
254 * Iterate over all cachefiles for the pool, past or present. When the
255 * cachefile is changed, the new one is pushed onto this list, allowing
256 * us to update previous cachefiles that no longer contain this pool.
257 */
258 ccw_failure = B_FALSE;
259 for (dp = list_head(&target->spa_config_list); dp != NULL;
260 dp = list_next(&target->spa_config_list, dp)) {
261 spa_t *spa = NULL;
262 if (dp->scd_path == NULL)
263 continue;
264
265 /*
266 * Iterate over all pools, adding any matching pools to 'nvl'.
267 */
268 nvl = NULL;
269 while ((spa = spa_next(spa)) != NULL) {
270 /*
271 * Skip over our own pool if we're about to remove
272 * ourselves from the spa namespace or any pool that
273 * is readonly. Since we cannot guarantee that a
274 * readonly pool would successfully import upon reboot,
275 * we don't allow them to be written to the cache file.
276 */
277 if ((spa == target && removing) ||
278 !spa_writeable(spa))
279 continue;
280
281 mutex_enter(&spa->spa_props_lock);
282 tdp = list_head(&spa->spa_config_list);
283 if (spa->spa_config == NULL ||
284 tdp == NULL ||
285 tdp->scd_path == NULL ||
286 strcmp(tdp->scd_path, dp->scd_path) != 0) {
287 mutex_exit(&spa->spa_props_lock);
288 continue;
289 }
290
291 if (nvl == NULL)
292 nvl = fnvlist_alloc();
293
294 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME)
295 pool_name = fnvlist_lookup_string(
296 spa->spa_config, ZPOOL_CONFIG_POOL_NAME);
297 else
298 pool_name = spa_name(spa);
299
300 fnvlist_add_nvlist(nvl, pool_name, spa->spa_config);
301 mutex_exit(&spa->spa_props_lock);
302 }
303
304 error = spa_config_write(dp, nvl);
305 if (error != 0)
306 ccw_failure = B_TRUE;
307 nvlist_free(nvl);
308 }
309
310 if (ccw_failure) {
311 /*
312 * Keep trying so that configuration data is
313 * written if/when any temporary filesystem
314 * resource issues are resolved.
315 */
316 if (target->spa_ccw_fail_time == 0) {
317 (void) zfs_ereport_post(
318 FM_EREPORT_ZFS_CONFIG_CACHE_WRITE,
319 target, NULL, NULL, NULL, 0);
320 }
321 target->spa_ccw_fail_time = gethrtime();
322 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE);
323 } else {
324 /*
325 * Do not rate limit future attempts to update
326 * the config cache.
327 */
328 target->spa_ccw_fail_time = 0;
329 }
330
331 /*
332 * Remove any config entries older than the current one.
333 */
334 dp = list_head(&target->spa_config_list);
335 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
336 list_remove(&target->spa_config_list, tdp);
337 if (tdp->scd_path != NULL)
338 spa_strfree(tdp->scd_path);
339 kmem_free(tdp, sizeof (spa_config_dirent_t));
340 }
341
342 spa_config_generation++;
343
344 if (postsysevent)
345 spa_event_notify(target, NULL, NULL, ESC_ZFS_CONFIG_SYNC);
346 }
347
348 /*
349 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
350 * and we don't want to allow the local zone to see all the pools anyway.
351 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
352 * information for all pool visible within the zone.
353 */
354 nvlist_t *
spa_all_configs(uint64_t * generation)355 spa_all_configs(uint64_t *generation)
356 {
357 nvlist_t *pools;
358 spa_t *spa = NULL;
359
360 if (*generation == spa_config_generation)
361 return (NULL);
362
363 pools = fnvlist_alloc();
364
365 mutex_enter(&spa_namespace_lock);
366 while ((spa = spa_next(spa)) != NULL) {
367 if (INGLOBALZONE(curproc) ||
368 zone_dataset_visible(spa_name(spa), NULL)) {
369 mutex_enter(&spa->spa_props_lock);
370 fnvlist_add_nvlist(pools, spa_name(spa),
371 spa->spa_config);
372 mutex_exit(&spa->spa_props_lock);
373 }
374 }
375 *generation = spa_config_generation;
376 mutex_exit(&spa_namespace_lock);
377
378 return (pools);
379 }
380
381 void
spa_config_set(spa_t * spa,nvlist_t * config)382 spa_config_set(spa_t *spa, nvlist_t *config)
383 {
384 mutex_enter(&spa->spa_props_lock);
385 if (spa->spa_config != NULL && spa->spa_config != config)
386 nvlist_free(spa->spa_config);
387 spa->spa_config = config;
388 mutex_exit(&spa->spa_props_lock);
389 }
390
391 /*
392 * Generate the pool's configuration based on the current in-core state.
393 *
394 * We infer whether to generate a complete config or just one top-level config
395 * based on whether vd is the root vdev.
396 */
397 nvlist_t *
spa_config_generate(spa_t * spa,vdev_t * vd,uint64_t txg,int getstats)398 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
399 {
400 nvlist_t *config, *nvroot;
401 vdev_t *rvd = spa->spa_root_vdev;
402 unsigned long hostid = 0;
403 boolean_t locked = B_FALSE;
404 uint64_t split_guid;
405 char *pool_name;
406
407 if (vd == NULL) {
408 vd = rvd;
409 locked = B_TRUE;
410 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
411 }
412
413 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
414 (SCL_CONFIG | SCL_STATE));
415
416 /*
417 * If txg is -1, report the current value of spa->spa_config_txg.
418 */
419 if (txg == -1ULL)
420 txg = spa->spa_config_txg;
421
422 /*
423 * Originally, users had to handle spa namespace collisions by either
424 * exporting the already imported pool or by specifying a new name for
425 * the pool with a conflicting name. In the case of root pools from
426 * virtual guests, neither approach to collision resolution is
427 * reasonable. This is addressed by extending the new name syntax with
428 * an option to specify that the new name is temporary. When specified,
429 * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us
430 * to use the previous name, which we do below.
431 */
432 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
433 VERIFY0(nvlist_lookup_string(spa->spa_config,
434 ZPOOL_CONFIG_POOL_NAME, &pool_name));
435 } else
436 pool_name = spa_name(spa);
437
438 config = fnvlist_alloc();
439
440 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
441 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, pool_name);
442 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa));
443 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg);
444 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa));
445 fnvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA, spa->spa_errata);
446 if (spa->spa_comment != NULL)
447 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT,
448 spa->spa_comment);
449
450 hostid = spa_get_hostid(spa);
451 if (hostid != 0)
452 fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid);
453 fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname()->nodename);
454
455 int config_gen_flags = 0;
456 if (vd != rvd) {
457 fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
458 vd->vdev_top->vdev_guid);
459 fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
460 vd->vdev_guid);
461 if (vd->vdev_isspare)
462 fnvlist_add_uint64(config,
463 ZPOOL_CONFIG_IS_SPARE, 1ULL);
464 if (vd->vdev_islog)
465 fnvlist_add_uint64(config,
466 ZPOOL_CONFIG_IS_LOG, 1ULL);
467 vd = vd->vdev_top; /* label contains top config */
468 } else {
469 /*
470 * Only add the (potentially large) split information
471 * in the mos config, and not in the vdev labels
472 */
473 if (spa->spa_config_splitting != NULL)
474 fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT,
475 spa->spa_config_splitting);
476
477 fnvlist_add_boolean(config, ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS);
478
479 config_gen_flags |= VDEV_CONFIG_MOS;
480 }
481
482 /*
483 * Add the top-level config. We even add this on pools which
484 * don't support holes in the namespace.
485 */
486 vdev_top_config_generate(spa, config);
487
488 /*
489 * If we're splitting, record the original pool's guid.
490 */
491 if (spa->spa_config_splitting != NULL &&
492 nvlist_lookup_uint64(spa->spa_config_splitting,
493 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) {
494 fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, split_guid);
495 }
496
497 nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags);
498 fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot);
499 nvlist_free(nvroot);
500
501 /*
502 * Store what's necessary for reading the MOS in the label.
503 */
504 fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
505 spa->spa_label_features);
506
507 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
508 ddt_histogram_t *ddh;
509 ddt_stat_t *dds;
510 ddt_object_t *ddo;
511
512 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
513 ddt_get_dedup_histogram(spa, ddh);
514 fnvlist_add_uint64_array(config,
515 ZPOOL_CONFIG_DDT_HISTOGRAM,
516 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t));
517 kmem_free(ddh, sizeof (ddt_histogram_t));
518
519 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP);
520 ddt_get_dedup_object_stats(spa, ddo);
521 fnvlist_add_uint64_array(config,
522 ZPOOL_CONFIG_DDT_OBJ_STATS,
523 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t));
524 kmem_free(ddo, sizeof (ddt_object_t));
525
526 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP);
527 ddt_get_dedup_stats(spa, dds);
528 fnvlist_add_uint64_array(config,
529 ZPOOL_CONFIG_DDT_STATS,
530 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t));
531 kmem_free(dds, sizeof (ddt_stat_t));
532 }
533
534 if (locked)
535 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
536
537 return (config);
538 }
539
540 /*
541 * Update all disk labels, generate a fresh config based on the current
542 * in-core state, and sync the global config cache (do not sync the config
543 * cache if this is a booting rootpool).
544 */
545 void
spa_config_update(spa_t * spa,int what)546 spa_config_update(spa_t *spa, int what)
547 {
548 vdev_t *rvd = spa->spa_root_vdev;
549 uint64_t txg;
550 int c;
551
552 ASSERT(MUTEX_HELD(&spa_namespace_lock));
553
554 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
555 txg = spa_last_synced_txg(spa) + 1;
556 if (what == SPA_CONFIG_UPDATE_POOL) {
557 vdev_config_dirty(rvd);
558 } else {
559 /*
560 * If we have top-level vdevs that were added but have
561 * not yet been prepared for allocation, do that now.
562 * (It's safe now because the config cache is up to date,
563 * so it will be able to translate the new DVAs.)
564 * See comments in spa_vdev_add() for full details.
565 */
566 for (c = 0; c < rvd->vdev_children; c++) {
567 vdev_t *tvd = rvd->vdev_child[c];
568
569 /*
570 * Explicitly skip vdevs that are indirect or
571 * log vdevs that are being removed. The reason
572 * is that both of those can have vdev_ms_array
573 * set to 0 and we wouldn't want to change their
574 * metaslab size nor call vdev_expand() on them.
575 */
576 if (!vdev_is_concrete(tvd) ||
577 (tvd->vdev_islog && tvd->vdev_removing))
578 continue;
579
580 if (tvd->vdev_ms_array == 0)
581 vdev_metaslab_set_size(tvd);
582 vdev_expand(tvd, txg);
583 }
584 }
585 spa_config_exit(spa, SCL_ALL, FTAG);
586
587 /*
588 * Wait for the mosconfig to be regenerated and synced.
589 */
590 txg_wait_synced(spa->spa_dsl_pool, txg);
591
592 /*
593 * Update the global config cache to reflect the new mosconfig.
594 */
595 if (!spa->spa_is_root) {
596 spa_write_cachefile(spa, B_FALSE,
597 what != SPA_CONFIG_UPDATE_POOL);
598 }
599
600 if (what == SPA_CONFIG_UPDATE_POOL)
601 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
602 }
603
604 EXPORT_SYMBOL(spa_config_load);
605 EXPORT_SYMBOL(spa_all_configs);
606 EXPORT_SYMBOL(spa_config_set);
607 EXPORT_SYMBOL(spa_config_generate);
608 EXPORT_SYMBOL(spa_config_update);
609
610 /* BEGIN CSTYLED */
611 #ifdef __linux__
612 /* string sysctls require a char array on FreeBSD */
613 ZFS_MODULE_PARAM(zfs_spa, spa_, config_path, STRING, ZMOD_RD,
614 "SPA config file (/etc/zfs/zpool.cache)");
615 #endif
616
617 ZFS_MODULE_PARAM(zfs, zfs_, autoimport_disable, INT, ZMOD_RW,
618 "Disable pool import at module load");
619 /* END CSTYLED */
620