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, 2015 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 if (fsize == 0)
103 goto out;
104
105 buf = kmem_alloc(fsize, KM_SLEEP);
106
107 /*
108 * Read the nvlist from the file.
109 */
110 if (kobj_read_file(file, buf, fsize, 0) < 0)
111 goto out;
112
113 /*
114 * Unpack the nvlist.
115 */
116 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
117 goto out;
118
119 /*
120 * Iterate over all elements in the nvlist, creating a new spa_t for
121 * each one with the specified configuration.
122 */
123 mutex_enter(&spa_namespace_lock);
124 nvpair = NULL;
125 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
126 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)
127 continue;
128
129 child = fnvpair_value_nvlist(nvpair);
130
131 if (spa_lookup(nvpair_name(nvpair)) != NULL)
132 continue;
133 (void) spa_add(nvpair_name(nvpair), child, NULL);
134 }
135 mutex_exit(&spa_namespace_lock);
136
137 nvlist_free(nvlist);
138
139 out:
140 if (buf != NULL)
141 kmem_free(buf, fsize);
142
143 kobj_close_file(file);
144 }
145
146 static void
spa_config_clean(nvlist_t * nvl)147 spa_config_clean(nvlist_t *nvl)
148 {
149 nvlist_t **child;
150 nvlist_t *nvroot = NULL;
151 uint_t c, children;
152
153 if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
154 &children) == 0) {
155 for (c = 0; c < children; c++)
156 spa_config_clean(child[c]);
157 }
158
159 if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0)
160 spa_config_clean(nvroot);
161
162 nvlist_remove(nvl, ZPOOL_CONFIG_VDEV_STATS, DATA_TYPE_UINT64_ARRAY);
163 nvlist_remove(nvl, ZPOOL_CONFIG_SCAN_STATS, DATA_TYPE_UINT64_ARRAY);
164 }
165
166 static int
spa_config_write(spa_config_dirent_t * dp,nvlist_t * nvl)167 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
168 {
169 size_t buflen;
170 char *buf;
171 vnode_t *vp;
172 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
173 char *temp;
174 int err;
175
176 /*
177 * If the nvlist is empty (NULL), then remove the old cachefile.
178 */
179 if (nvl == NULL) {
180 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
181 return (err);
182 }
183
184 /*
185 * Pack the configuration into a buffer.
186 */
187 buf = fnvlist_pack(nvl, &buflen);
188 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
189
190 /*
191 * Write the configuration to disk. We need to do the traditional
192 * 'write to temporary file, sync, move over original' to make sure we
193 * always have a consistent view of the data.
194 */
195 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);
196
197 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0);
198 if (err == 0) {
199 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
200 0, RLIM64_INFINITY, kcred, NULL);
201 if (err == 0)
202 err = VOP_FSYNC(vp, FSYNC, kcred, NULL);
203 if (err == 0)
204 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE);
205 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
206 }
207
208 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE);
209
210 fnvlist_pack_free(buf, buflen);
211 kmem_free(temp, MAXPATHLEN);
212 return (err);
213 }
214
215 /*
216 * Synchronize pool configuration to disk. This must be called with the
217 * namespace lock held. Synchronizing the pool cache is typically done after
218 * the configuration has been synced to the MOS. This exposes a window where
219 * the MOS config will have been updated but the cache file has not. If
220 * the system were to crash at that instant then the cached config may not
221 * contain the correct information to open the pool and an explicity import
222 * would be required.
223 */
224 void
spa_config_sync(spa_t * target,boolean_t removing,boolean_t postsysevent)225 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
226 {
227 spa_config_dirent_t *dp, *tdp;
228 nvlist_t *nvl;
229 boolean_t ccw_failure;
230 int error;
231
232 ASSERT(MUTEX_HELD(&spa_namespace_lock));
233
234 if (rootdir == NULL || !(spa_mode_global & FWRITE))
235 return;
236
237 /*
238 * Iterate over all cachefiles for the pool, past or present. When the
239 * cachefile is changed, the new one is pushed onto this list, allowing
240 * us to update previous cachefiles that no longer contain this pool.
241 */
242 ccw_failure = B_FALSE;
243 for (dp = list_head(&target->spa_config_list); dp != NULL;
244 dp = list_next(&target->spa_config_list, dp)) {
245 spa_t *spa = NULL;
246 if (dp->scd_path == NULL)
247 continue;
248
249 /*
250 * Iterate over all pools, adding any matching pools to 'nvl'.
251 */
252 nvl = NULL;
253 while ((spa = spa_next(spa)) != NULL) {
254 nvlist_t *nvroot = NULL;
255 /*
256 * Skip over our own pool if we're about to remove
257 * ourselves from the spa namespace or any pool that
258 * is readonly. Since we cannot guarantee that a
259 * readonly pool would successfully import upon reboot,
260 * we don't allow them to be written to the cache file.
261 */
262 if ((spa == target && removing) ||
263 (spa_state(spa) == POOL_STATE_ACTIVE &&
264 !spa_writeable(spa)))
265 continue;
266
267 mutex_enter(&spa->spa_props_lock);
268 tdp = list_head(&spa->spa_config_list);
269 if (spa->spa_config == NULL ||
270 tdp->scd_path == NULL ||
271 strcmp(tdp->scd_path, dp->scd_path) != 0) {
272 mutex_exit(&spa->spa_props_lock);
273 continue;
274 }
275
276 if (nvl == NULL)
277 nvl = fnvlist_alloc();
278
279 fnvlist_add_nvlist(nvl, spa->spa_name,
280 spa->spa_config);
281 mutex_exit(&spa->spa_props_lock);
282
283 if (nvlist_lookup_nvlist(nvl, spa->spa_name, &nvroot) == 0)
284 spa_config_clean(nvroot);
285 }
286
287 error = spa_config_write(dp, nvl);
288 if (error != 0)
289 ccw_failure = B_TRUE;
290 nvlist_free(nvl);
291 }
292
293 if (ccw_failure) {
294 /*
295 * Keep trying so that configuration data is
296 * written if/when any temporary filesystem
297 * resource issues are resolved.
298 */
299 if (target->spa_ccw_fail_time == 0) {
300 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE,
301 target, NULL, NULL, 0, 0);
302 }
303 target->spa_ccw_fail_time = gethrtime();
304 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE);
305 } else {
306 /*
307 * Do not rate limit future attempts to update
308 * the config cache.
309 */
310 target->spa_ccw_fail_time = 0;
311 }
312
313 /*
314 * Remove any config entries older than the current one.
315 */
316 dp = list_head(&target->spa_config_list);
317 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
318 list_remove(&target->spa_config_list, tdp);
319 if (tdp->scd_path != NULL)
320 spa_strfree(tdp->scd_path);
321 kmem_free(tdp, sizeof (spa_config_dirent_t));
322 }
323
324 spa_config_generation++;
325
326 if (postsysevent)
327 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC);
328 }
329
330 /*
331 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
332 * and we don't want to allow the local zone to see all the pools anyway.
333 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
334 * information for all pool visible within the zone.
335 */
336 nvlist_t *
spa_all_configs(uint64_t * generation)337 spa_all_configs(uint64_t *generation)
338 {
339 nvlist_t *pools;
340 spa_t *spa = NULL;
341
342 if (*generation == spa_config_generation)
343 return (NULL);
344
345 pools = fnvlist_alloc();
346
347 mutex_enter(&spa_namespace_lock);
348 while ((spa = spa_next(spa)) != NULL) {
349 if (INGLOBALZONE(curthread) ||
350 zone_dataset_visible(spa_name(spa), NULL)) {
351 mutex_enter(&spa->spa_props_lock);
352 fnvlist_add_nvlist(pools, spa_name(spa),
353 spa->spa_config);
354 mutex_exit(&spa->spa_props_lock);
355 }
356 }
357 *generation = spa_config_generation;
358 mutex_exit(&spa_namespace_lock);
359
360 return (pools);
361 }
362
363 void
spa_config_set(spa_t * spa,nvlist_t * config)364 spa_config_set(spa_t *spa, nvlist_t *config)
365 {
366 mutex_enter(&spa->spa_props_lock);
367 nvlist_free(spa->spa_config);
368 spa->spa_config = config;
369 mutex_exit(&spa->spa_props_lock);
370 }
371
372 /*
373 * Generate the pool's configuration based on the current in-core state.
374 *
375 * We infer whether to generate a complete config or just one top-level config
376 * based on whether vd is the root vdev.
377 */
378 nvlist_t *
spa_config_generate(spa_t * spa,vdev_t * vd,uint64_t txg,int getstats)379 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
380 {
381 nvlist_t *config, *nvroot;
382 vdev_t *rvd = spa->spa_root_vdev;
383 unsigned long hostid = 0;
384 boolean_t locked = B_FALSE;
385 uint64_t split_guid;
386
387 if (vd == NULL) {
388 vd = rvd;
389 locked = B_TRUE;
390 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
391 }
392
393 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
394 (SCL_CONFIG | SCL_STATE));
395
396 /*
397 * If txg is -1, report the current value of spa->spa_config_txg.
398 */
399 if (txg == -1ULL)
400 txg = spa->spa_config_txg;
401
402 config = fnvlist_alloc();
403
404 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
405 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, spa_name(spa));
406 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa));
407 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg);
408 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa));
409 if (spa->spa_comment != NULL) {
410 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT,
411 spa->spa_comment);
412 }
413
414 #ifdef _KERNEL
415 hostid = zone_get_hostid(NULL);
416 #else /* _KERNEL */
417 /*
418 * We're emulating the system's hostid in userland, so we can't use
419 * zone_get_hostid().
420 */
421 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
422 #endif /* _KERNEL */
423 if (hostid != 0) {
424 fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid);
425 }
426 fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname.nodename);
427
428 int config_gen_flags = 0;
429 if (vd != rvd) {
430 fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
431 vd->vdev_top->vdev_guid);
432 fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
433 vd->vdev_guid);
434 if (vd->vdev_isspare) {
435 fnvlist_add_uint64(config,
436 ZPOOL_CONFIG_IS_SPARE, 1ULL);
437 }
438 if (vd->vdev_islog) {
439 fnvlist_add_uint64(config,
440 ZPOOL_CONFIG_IS_LOG, 1ULL);
441 }
442 vd = vd->vdev_top; /* label contains top config */
443 } else {
444 /*
445 * Only add the (potentially large) split information
446 * in the mos config, and not in the vdev labels
447 */
448 if (spa->spa_config_splitting != NULL)
449 fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT,
450 spa->spa_config_splitting);
451 fnvlist_add_boolean(config,
452 ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS);
453
454 config_gen_flags |= VDEV_CONFIG_MOS;
455 }
456
457 /*
458 * Add the top-level config. We even add this on pools which
459 * don't support holes in the namespace.
460 */
461 vdev_top_config_generate(spa, config);
462
463 /*
464 * If we're splitting, record the original pool's guid.
465 */
466 if (spa->spa_config_splitting != NULL &&
467 nvlist_lookup_uint64(spa->spa_config_splitting,
468 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) {
469 fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID,
470 split_guid);
471 }
472
473 nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags);
474 fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot);
475 nvlist_free(nvroot);
476
477 /*
478 * Store what's necessary for reading the MOS in the label.
479 */
480 fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
481 spa->spa_label_features);
482
483 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
484 ddt_histogram_t *ddh;
485 ddt_stat_t *dds;
486 ddt_object_t *ddo;
487
488 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
489 ddt_get_dedup_histogram(spa, ddh);
490 fnvlist_add_uint64_array(config,
491 ZPOOL_CONFIG_DDT_HISTOGRAM,
492 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t));
493 kmem_free(ddh, sizeof (ddt_histogram_t));
494
495 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP);
496 ddt_get_dedup_object_stats(spa, ddo);
497 fnvlist_add_uint64_array(config,
498 ZPOOL_CONFIG_DDT_OBJ_STATS,
499 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t));
500 kmem_free(ddo, sizeof (ddt_object_t));
501
502 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP);
503 ddt_get_dedup_stats(spa, dds);
504 fnvlist_add_uint64_array(config,
505 ZPOOL_CONFIG_DDT_STATS,
506 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t));
507 kmem_free(dds, sizeof (ddt_stat_t));
508 }
509
510 if (locked)
511 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
512
513 return (config);
514 }
515
516 /*
517 * Update all disk labels, generate a fresh config based on the current
518 * in-core state, and sync the global config cache (do not sync the config
519 * cache if this is a booting rootpool).
520 */
521 void
spa_config_update(spa_t * spa,int what)522 spa_config_update(spa_t *spa, int what)
523 {
524 vdev_t *rvd = spa->spa_root_vdev;
525 uint64_t txg;
526 int c;
527
528 ASSERT(MUTEX_HELD(&spa_namespace_lock));
529
530 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
531 txg = spa_last_synced_txg(spa) + 1;
532 if (what == SPA_CONFIG_UPDATE_POOL) {
533 vdev_config_dirty(rvd);
534 } else {
535 /*
536 * If we have top-level vdevs that were added but have
537 * not yet been prepared for allocation, do that now.
538 * (It's safe now because the config cache is up to date,
539 * so it will be able to translate the new DVAs.)
540 * See comments in spa_vdev_add() for full details.
541 */
542 for (c = 0; c < rvd->vdev_children; c++) {
543 vdev_t *tvd = rvd->vdev_child[c];
544 if (tvd->vdev_ms_array == 0) {
545 vdev_ashift_optimize(tvd);
546 vdev_metaslab_set_size(tvd);
547 }
548 vdev_expand(tvd, txg);
549 }
550 }
551 spa_config_exit(spa, SCL_ALL, FTAG);
552
553 /*
554 * Wait for the mosconfig to be regenerated and synced.
555 */
556 txg_wait_synced(spa->spa_dsl_pool, txg);
557
558 /*
559 * Update the global config cache to reflect the new mosconfig.
560 */
561 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
562
563 if (what == SPA_CONFIG_UPDATE_POOL)
564 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
565 }
566