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) 2013 by Delphix. All rights reserved.
26 */
27
28 #include <sys/zfs_context.h>
29 #include <sys/spa.h>
30 #include <sys/fm/fs/zfs.h>
31 #include <sys/spa_impl.h>
32 #include <sys/nvpair.h>
33 #include <sys/uio.h>
34 #include <sys/fs/zfs.h>
35 #include <sys/vdev_impl.h>
36 #include <sys/zfs_ioctl.h>
37 #include <sys/utsname.h>
38 #include <sys/sunddi.h>
39 #include <sys/zfeature.h>
40 #ifdef _KERNEL
41 #include <sys/kobj.h>
42 #include <sys/zone.h>
43 #endif
44
45 /*
46 * Pool configuration repository.
47 *
48 * Pool configuration is stored as a packed nvlist on the filesystem. By
49 * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot
50 * (when the ZFS module is loaded). Pools can also have the 'cachefile'
51 * property set that allows them to be stored in an alternate location until
52 * the control of external software.
53 *
54 * For each cache file, we have a single nvlist which holds all the
55 * configuration information. When the module loads, we read this information
56 * from /etc/zfs/zpool.cache and populate the SPA namespace. This namespace is
57 * maintained independently in spa.c. Whenever the namespace is modified, or
58 * the configuration of a pool is changed, we call spa_config_sync(), which
59 * walks through all the active pools and writes the configuration to disk.
60 */
61
62 static uint64_t spa_config_generation = 1;
63
64 /*
65 * This can be overridden in userland to preserve an alternate namespace for
66 * userland pools when doing testing.
67 */
68 const char *spa_config_path = ZPOOL_CACHE;
69
70 /*
71 * Called when the module is first loaded, this routine loads the configuration
72 * file into the SPA namespace. It does not actually open or load the pools; it
73 * only populates the namespace.
74 */
75 void
spa_config_load(void)76 spa_config_load(void)
77 {
78 void *buf = NULL;
79 nvlist_t *nvlist, *child;
80 nvpair_t *nvpair;
81 char *pathname;
82 struct _buf *file;
83 uint64_t fsize;
84
85 /*
86 * Open the configuration file.
87 */
88 pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
89
90 (void) snprintf(pathname, MAXPATHLEN, "%s", spa_config_path);
91
92 file = kobj_open_file(pathname);
93
94 kmem_free(pathname, MAXPATHLEN);
95
96 if (file == (struct _buf *)-1)
97 return;
98
99 if (kobj_get_filesize(file, &fsize) != 0)
100 goto out;
101
102 buf = kmem_alloc(fsize, KM_SLEEP);
103
104 /*
105 * Read the nvlist from the file.
106 */
107 if (kobj_read_file(file, buf, fsize, 0) < 0)
108 goto out;
109
110 /*
111 * Unpack the nvlist.
112 */
113 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
114 goto out;
115
116 /*
117 * Iterate over all elements in the nvlist, creating a new spa_t for
118 * each one with the specified configuration.
119 */
120 mutex_enter(&spa_namespace_lock);
121 nvpair = NULL;
122 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
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 (void) spa_add(nvpair_name(nvpair), child, NULL);
131 }
132 mutex_exit(&spa_namespace_lock);
133
134 nvlist_free(nvlist);
135
136 out:
137 if (buf != NULL)
138 kmem_free(buf, fsize);
139
140 kobj_close_file(file);
141 }
142
143 static void
spa_config_clean(nvlist_t * nvl)144 spa_config_clean(nvlist_t *nvl)
145 {
146 nvlist_t **child;
147 nvlist_t *nvroot = NULL;
148 uint_t c, children;
149
150 if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
151 &children) == 0) {
152 for (c = 0; c < children; c++)
153 spa_config_clean(child[c]);
154 }
155
156 if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0)
157 spa_config_clean(nvroot);
158
159 nvlist_remove(nvl, ZPOOL_CONFIG_VDEV_STATS, DATA_TYPE_UINT64_ARRAY);
160 nvlist_remove(nvl, ZPOOL_CONFIG_SCAN_STATS, DATA_TYPE_UINT64_ARRAY);
161 }
162
163 static int
spa_config_write(spa_config_dirent_t * dp,nvlist_t * nvl)164 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
165 {
166 size_t buflen;
167 char *buf;
168 vnode_t *vp;
169 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
170 char *temp;
171 int err;
172
173 /*
174 * If the nvlist is empty (NULL), then remove the old cachefile.
175 */
176 if (nvl == NULL) {
177 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
178 return (err);
179 }
180
181 /*
182 * Pack the configuration into a buffer.
183 */
184 VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0);
185
186 buf = kmem_alloc(buflen, KM_SLEEP);
187 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
188
189 VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR,
190 KM_SLEEP) == 0);
191
192 /*
193 * Write the configuration to disk. We need to do the traditional
194 * 'write to temporary file, sync, move over original' to make sure we
195 * always have a consistent view of the data.
196 */
197 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);
198
199 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0);
200 if (err == 0) {
201 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
202 0, RLIM64_INFINITY, kcred, NULL);
203 if (err == 0)
204 err = VOP_FSYNC(vp, FSYNC, kcred, NULL);
205 if (err == 0)
206 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE);
207 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
208 }
209
210 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE);
211
212 kmem_free(buf, buflen);
213 kmem_free(temp, MAXPATHLEN);
214 return (err);
215 }
216
217 /*
218 * Synchronize pool configuration to disk. This must be called with the
219 * namespace lock held. Synchronizing the pool cache is typically done after
220 * the configuration has been synced to the MOS. This exposes a window where
221 * the MOS config will have been updated but the cache file has not. If
222 * the system were to crash at that instant then the cached config may not
223 * contain the correct information to open the pool and an explicity import
224 * would be required.
225 */
226 void
spa_config_sync(spa_t * target,boolean_t removing,boolean_t postsysevent)227 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
228 {
229 spa_config_dirent_t *dp, *tdp;
230 nvlist_t *nvl;
231 boolean_t ccw_failure;
232 int error;
233 char *pool_name;
234
235 ASSERT(MUTEX_HELD(&spa_namespace_lock));
236
237 if (rootdir == NULL || !(spa_mode_global & FWRITE))
238 return;
239
240 /*
241 * Iterate over all cachefiles for the pool, past or present. When the
242 * cachefile is changed, the new one is pushed onto this list, allowing
243 * us to update previous cachefiles that no longer contain this pool.
244 */
245 ccw_failure = B_FALSE;
246 for (dp = list_head(&target->spa_config_list); dp != NULL;
247 dp = list_next(&target->spa_config_list, dp)) {
248 spa_t *spa = NULL;
249 if (dp->scd_path == NULL)
250 continue;
251
252 /*
253 * Iterate over all pools, adding any matching pools to 'nvl'.
254 */
255 nvl = NULL;
256 while ((spa = spa_next(spa)) != NULL) {
257 nvlist_t *nvroot = NULL;
258 /*
259 * Skip over our own pool if we're about to remove
260 * ourselves from the spa namespace or any pool that
261 * is readonly. Since we cannot guarantee that a
262 * readonly pool would successfully import upon reboot,
263 * we don't allow them to be written to the cache file.
264 */
265 if ((spa == target && removing) ||
266 (spa_state(spa) == POOL_STATE_ACTIVE &&
267 !spa_writeable(spa)))
268 continue;
269
270 mutex_enter(&spa->spa_props_lock);
271 tdp = list_head(&spa->spa_config_list);
272 if (spa->spa_config == NULL ||
273 tdp->scd_path == NULL ||
274 strcmp(tdp->scd_path, dp->scd_path) != 0) {
275 mutex_exit(&spa->spa_props_lock);
276 continue;
277 }
278
279 if (nvl == NULL)
280 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME,
281 KM_SLEEP) == 0);
282
283 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
284 pool_name = fnvlist_lookup_string(spa->spa_config,
285 ZPOOL_CONFIG_POOL_NAME);
286 } else {
287 pool_name = spa_name(spa);
288 }
289
290 fnvlist_add_nvlist(nvl, pool_name,
291 spa->spa_config);
292 mutex_exit(&spa->spa_props_lock);
293
294 if (nvlist_lookup_nvlist(nvl, pool_name, &nvroot) == 0)
295 spa_config_clean(nvroot);
296 }
297
298 error = spa_config_write(dp, nvl);
299 if (error != 0)
300 ccw_failure = B_TRUE;
301 nvlist_free(nvl);
302 }
303
304 if (ccw_failure) {
305 /*
306 * Keep trying so that configuration data is
307 * written if/when any temporary filesystem
308 * resource issues are resolved.
309 */
310 if (target->spa_ccw_fail_time == 0) {
311 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE,
312 target, NULL, NULL, 0, 0);
313 }
314 target->spa_ccw_fail_time = gethrtime();
315 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE);
316 } else {
317 /*
318 * Do not rate limit future attempts to update
319 * the config cache.
320 */
321 target->spa_ccw_fail_time = 0;
322 }
323
324 /*
325 * Remove any config entries older than the current one.
326 */
327 dp = list_head(&target->spa_config_list);
328 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
329 list_remove(&target->spa_config_list, tdp);
330 if (tdp->scd_path != NULL)
331 spa_strfree(tdp->scd_path);
332 kmem_free(tdp, sizeof (spa_config_dirent_t));
333 }
334
335 spa_config_generation++;
336
337 if (postsysevent)
338 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC);
339 }
340
341 /*
342 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
343 * and we don't want to allow the local zone to see all the pools anyway.
344 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
345 * information for all pool visible within the zone.
346 */
347 nvlist_t *
spa_all_configs(uint64_t * generation)348 spa_all_configs(uint64_t *generation)
349 {
350 nvlist_t *pools;
351 spa_t *spa = NULL;
352
353 if (*generation == spa_config_generation)
354 return (NULL);
355
356 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);
357
358 mutex_enter(&spa_namespace_lock);
359 while ((spa = spa_next(spa)) != NULL) {
360 if (INGLOBALZONE(curthread) ||
361 zone_dataset_visible(spa_name(spa), NULL)) {
362 mutex_enter(&spa->spa_props_lock);
363 VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
364 spa->spa_config) == 0);
365 mutex_exit(&spa->spa_props_lock);
366 }
367 }
368 *generation = spa_config_generation;
369 mutex_exit(&spa_namespace_lock);
370
371 return (pools);
372 }
373
374 void
spa_config_set(spa_t * spa,nvlist_t * config)375 spa_config_set(spa_t *spa, nvlist_t *config)
376 {
377 mutex_enter(&spa->spa_props_lock);
378 nvlist_free(spa->spa_config);
379 spa->spa_config = config;
380 mutex_exit(&spa->spa_props_lock);
381 }
382
383 /*
384 * Generate the pool's configuration based on the current in-core state.
385 *
386 * We infer whether to generate a complete config or just one top-level config
387 * based on whether vd is the root vdev.
388 */
389 nvlist_t *
spa_config_generate(spa_t * spa,vdev_t * vd,uint64_t txg,int getstats)390 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
391 {
392 nvlist_t *config, *nvroot;
393 vdev_t *rvd = spa->spa_root_vdev;
394 unsigned long hostid = 0;
395 boolean_t locked = B_FALSE;
396 uint64_t split_guid;
397 char *pool_name;
398
399 if (vd == NULL) {
400 vd = rvd;
401 locked = B_TRUE;
402 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
403 }
404
405 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
406 (SCL_CONFIG | SCL_STATE));
407
408 /*
409 * If txg is -1, report the current value of spa->spa_config_txg.
410 */
411 if (txg == -1ULL)
412 txg = spa->spa_config_txg;
413
414 /*
415 * Originally, users had to handle spa namespace collisions by either
416 * exporting the already imported pool or by specifying a new name for
417 * the pool with a conflicting name. In the case of root pools from
418 * virtual guests, neither approach to collision resolution is
419 * reasonable. This is addressed by extending the new name syntax with
420 * an option to specify that the new name is temporary. When specified,
421 * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us
422 * to use the previous name, which we do below.
423 */
424 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
425 pool_name = fnvlist_lookup_string(spa->spa_config,
426 ZPOOL_CONFIG_POOL_NAME);
427 } else {
428 pool_name = spa_name(spa);
429 }
430
431 config = fnvlist_alloc();
432
433 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
434 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, pool_name);
435 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa));
436 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg);
437 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa));
438 if (spa->spa_comment != NULL) {
439 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT,
440 spa->spa_comment);
441 }
442
443
444 #ifdef _KERNEL
445 hostid = zone_get_hostid(NULL);
446 #else /* _KERNEL */
447 /*
448 * We're emulating the system's hostid in userland, so we can't use
449 * zone_get_hostid().
450 */
451 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
452 #endif /* _KERNEL */
453 if (hostid != 0) {
454 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
455 hostid) == 0);
456 }
457 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
458 utsname.nodename) == 0);
459
460 if (vd != rvd) {
461 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
462 vd->vdev_top->vdev_guid) == 0);
463 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
464 vd->vdev_guid) == 0);
465 if (vd->vdev_isspare)
466 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,
467 1ULL) == 0);
468 if (vd->vdev_islog)
469 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,
470 1ULL) == 0);
471 vd = vd->vdev_top; /* label contains top config */
472 } else {
473 /*
474 * Only add the (potentially large) split information
475 * in the mos config, and not in the vdev labels
476 */
477 if (spa->spa_config_splitting != NULL)
478 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT,
479 spa->spa_config_splitting) == 0);
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 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID,
495 split_guid) == 0);
496 }
497
498 nvroot = vdev_config_generate(spa, vd, getstats, 0);
499 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
500 nvlist_free(nvroot);
501
502 /*
503 * Store what's necessary for reading the MOS in the label.
504 */
505 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
506 spa->spa_label_features) == 0);
507
508 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
509 ddt_histogram_t *ddh;
510 ddt_stat_t *dds;
511 ddt_object_t *ddo;
512
513 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
514 ddt_get_dedup_histogram(spa, ddh);
515 VERIFY(nvlist_add_uint64_array(config,
516 ZPOOL_CONFIG_DDT_HISTOGRAM,
517 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)) == 0);
518 kmem_free(ddh, sizeof (ddt_histogram_t));
519
520 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP);
521 ddt_get_dedup_object_stats(spa, ddo);
522 VERIFY(nvlist_add_uint64_array(config,
523 ZPOOL_CONFIG_DDT_OBJ_STATS,
524 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)) == 0);
525 kmem_free(ddo, sizeof (ddt_object_t));
526
527 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP);
528 ddt_get_dedup_stats(spa, dds);
529 VERIFY(nvlist_add_uint64_array(config,
530 ZPOOL_CONFIG_DDT_STATS,
531 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)) == 0);
532 kmem_free(dds, sizeof (ddt_stat_t));
533 }
534
535 if (locked)
536 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
537
538 return (config);
539 }
540
541 /*
542 * Update all disk labels, generate a fresh config based on the current
543 * in-core state, and sync the global config cache (do not sync the config
544 * cache if this is a booting rootpool).
545 */
546 void
spa_config_update(spa_t * spa,int what)547 spa_config_update(spa_t *spa, int what)
548 {
549 vdev_t *rvd = spa->spa_root_vdev;
550 uint64_t txg;
551 int c;
552
553 ASSERT(MUTEX_HELD(&spa_namespace_lock));
554
555 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
556 txg = spa_last_synced_txg(spa) + 1;
557 if (what == SPA_CONFIG_UPDATE_POOL) {
558 vdev_config_dirty(rvd);
559 } else {
560 /*
561 * If we have top-level vdevs that were added but have
562 * not yet been prepared for allocation, do that now.
563 * (It's safe now because the config cache is up to date,
564 * so it will be able to translate the new DVAs.)
565 * See comments in spa_vdev_add() for full details.
566 */
567 for (c = 0; c < rvd->vdev_children; c++) {
568 vdev_t *tvd = rvd->vdev_child[c];
569 if (tvd->vdev_ms_array == 0) {
570 vdev_ashift_optimize(tvd);
571 vdev_metaslab_set_size(tvd);
572 }
573 vdev_expand(tvd, txg);
574 }
575 }
576 spa_config_exit(spa, SCL_ALL, FTAG);
577
578 /*
579 * Wait for the mosconfig to be regenerated and synced.
580 */
581 txg_wait_synced(spa->spa_dsl_pool, txg);
582
583 /*
584 * Update the global config cache to reflect the new mosconfig.
585 */
586 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
587
588 if (what == SPA_CONFIG_UPDATE_POOL)
589 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
590 }
591