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 int
spa_config_write(spa_config_dirent_t * dp,nvlist_t * nvl)144 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
145 {
146 size_t buflen;
147 char *buf;
148 vnode_t *vp;
149 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
150 char *temp;
151 int err;
152
153 /*
154 * If the nvlist is empty (NULL), then remove the old cachefile.
155 */
156 if (nvl == NULL) {
157 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
158 return (err);
159 }
160
161 /*
162 * Pack the configuration into a buffer.
163 */
164 VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0);
165
166 buf = kmem_alloc(buflen, KM_SLEEP);
167 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
168
169 VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR,
170 KM_SLEEP) == 0);
171
172 /*
173 * Write the configuration to disk. We need to do the traditional
174 * 'write to temporary file, sync, move over original' to make sure we
175 * always have a consistent view of the data.
176 */
177 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);
178
179 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0);
180 if (err == 0) {
181 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
182 0, RLIM64_INFINITY, kcred, NULL);
183 if (err == 0)
184 err = VOP_FSYNC(vp, FSYNC, kcred, NULL);
185 if (err == 0)
186 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE);
187 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
188 }
189
190 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE);
191
192 kmem_free(buf, buflen);
193 kmem_free(temp, MAXPATHLEN);
194 return (err);
195 }
196
197 /*
198 * Synchronize pool configuration to disk. This must be called with the
199 * namespace lock held. Synchronizing the pool cache is typically done after
200 * the configuration has been synced to the MOS. This exposes a window where
201 * the MOS config will have been updated but the cache file has not. If
202 * the system were to crash at that instant then the cached config may not
203 * contain the correct information to open the pool and an explicity import
204 * would be required.
205 */
206 void
spa_config_sync(spa_t * target,boolean_t removing,boolean_t postsysevent)207 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
208 {
209 spa_config_dirent_t *dp, *tdp;
210 nvlist_t *nvl;
211 boolean_t ccw_failure;
212 int error;
213
214 ASSERT(MUTEX_HELD(&spa_namespace_lock));
215
216 if (rootdir == NULL || !(spa_mode_global & FWRITE))
217 return;
218
219 /*
220 * Iterate over all cachefiles for the pool, past or present. When the
221 * cachefile is changed, the new one is pushed onto this list, allowing
222 * us to update previous cachefiles that no longer contain this pool.
223 */
224 ccw_failure = B_FALSE;
225 for (dp = list_head(&target->spa_config_list); dp != NULL;
226 dp = list_next(&target->spa_config_list, dp)) {
227 spa_t *spa = NULL;
228 if (dp->scd_path == NULL)
229 continue;
230
231 /*
232 * Iterate over all pools, adding any matching pools to 'nvl'.
233 */
234 nvl = NULL;
235 while ((spa = spa_next(spa)) != NULL) {
236 /*
237 * Skip over our own pool if we're about to remove
238 * ourselves from the spa namespace or any pool that
239 * is readonly. Since we cannot guarantee that a
240 * readonly pool would successfully import upon reboot,
241 * we don't allow them to be written to the cache file.
242 */
243 if ((spa == target && removing) ||
244 !spa_writeable(spa))
245 continue;
246
247 mutex_enter(&spa->spa_props_lock);
248 tdp = list_head(&spa->spa_config_list);
249 if (spa->spa_config == NULL ||
250 tdp->scd_path == NULL ||
251 strcmp(tdp->scd_path, dp->scd_path) != 0) {
252 mutex_exit(&spa->spa_props_lock);
253 continue;
254 }
255
256 if (nvl == NULL)
257 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME,
258 KM_SLEEP) == 0);
259
260 VERIFY(nvlist_add_nvlist(nvl, spa->spa_name,
261 spa->spa_config) == 0);
262 mutex_exit(&spa->spa_props_lock);
263 }
264
265 error = spa_config_write(dp, nvl);
266 if (error != 0)
267 ccw_failure = B_TRUE;
268 nvlist_free(nvl);
269 }
270
271 if (ccw_failure) {
272 /*
273 * Keep trying so that configuration data is
274 * written if/when any temporary filesystem
275 * resource issues are resolved.
276 */
277 if (target->spa_ccw_fail_time == 0) {
278 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE,
279 target, NULL, NULL, 0, 0);
280 }
281 target->spa_ccw_fail_time = gethrtime();
282 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE);
283 } else {
284 /*
285 * Do not rate limit future attempts to update
286 * the config cache.
287 */
288 target->spa_ccw_fail_time = 0;
289 }
290
291 /*
292 * Remove any config entries older than the current one.
293 */
294 dp = list_head(&target->spa_config_list);
295 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
296 list_remove(&target->spa_config_list, tdp);
297 if (tdp->scd_path != NULL)
298 spa_strfree(tdp->scd_path);
299 kmem_free(tdp, sizeof (spa_config_dirent_t));
300 }
301
302 spa_config_generation++;
303
304 if (postsysevent)
305 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC);
306 }
307
308 /*
309 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
310 * and we don't want to allow the local zone to see all the pools anyway.
311 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
312 * information for all pool visible within the zone.
313 */
314 nvlist_t *
spa_all_configs(uint64_t * generation)315 spa_all_configs(uint64_t *generation)
316 {
317 nvlist_t *pools;
318 spa_t *spa = NULL;
319
320 if (*generation == spa_config_generation)
321 return (NULL);
322
323 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);
324
325 mutex_enter(&spa_namespace_lock);
326 while ((spa = spa_next(spa)) != NULL) {
327 if (INGLOBALZONE(curthread) ||
328 zone_dataset_visible(spa_name(spa), NULL)) {
329 mutex_enter(&spa->spa_props_lock);
330 VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
331 spa->spa_config) == 0);
332 mutex_exit(&spa->spa_props_lock);
333 }
334 }
335 *generation = spa_config_generation;
336 mutex_exit(&spa_namespace_lock);
337
338 return (pools);
339 }
340
341 void
spa_config_set(spa_t * spa,nvlist_t * config)342 spa_config_set(spa_t *spa, nvlist_t *config)
343 {
344 mutex_enter(&spa->spa_props_lock);
345 if (spa->spa_config != NULL)
346 nvlist_free(spa->spa_config);
347 spa->spa_config = config;
348 mutex_exit(&spa->spa_props_lock);
349 }
350
351 /*
352 * Generate the pool's configuration based on the current in-core state.
353 *
354 * We infer whether to generate a complete config or just one top-level config
355 * based on whether vd is the root vdev.
356 */
357 nvlist_t *
spa_config_generate(spa_t * spa,vdev_t * vd,uint64_t txg,int getstats)358 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
359 {
360 nvlist_t *config, *nvroot;
361 vdev_t *rvd = spa->spa_root_vdev;
362 unsigned long hostid = 0;
363 boolean_t locked = B_FALSE;
364 uint64_t split_guid;
365
366 if (vd == NULL) {
367 vd = rvd;
368 locked = B_TRUE;
369 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
370 }
371
372 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
373 (SCL_CONFIG | SCL_STATE));
374
375 /*
376 * If txg is -1, report the current value of spa->spa_config_txg.
377 */
378 if (txg == -1ULL)
379 txg = spa->spa_config_txg;
380
381 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);
382
383 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
384 spa_version(spa)) == 0);
385 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
386 spa_name(spa)) == 0);
387 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
388 spa_state(spa)) == 0);
389 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
390 txg) == 0);
391 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
392 spa_guid(spa)) == 0);
393 VERIFY(spa->spa_comment == NULL || nvlist_add_string(config,
394 ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0);
395
396
397 #ifdef _KERNEL
398 hostid = zone_get_hostid(NULL);
399 #else /* _KERNEL */
400 /*
401 * We're emulating the system's hostid in userland, so we can't use
402 * zone_get_hostid().
403 */
404 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
405 #endif /* _KERNEL */
406 if (hostid != 0) {
407 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
408 hostid) == 0);
409 }
410 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
411 utsname.nodename) == 0);
412
413 if (vd != rvd) {
414 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
415 vd->vdev_top->vdev_guid) == 0);
416 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
417 vd->vdev_guid) == 0);
418 if (vd->vdev_isspare)
419 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,
420 1ULL) == 0);
421 if (vd->vdev_islog)
422 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,
423 1ULL) == 0);
424 vd = vd->vdev_top; /* label contains top config */
425 } else {
426 /*
427 * Only add the (potentially large) split information
428 * in the mos config, and not in the vdev labels
429 */
430 if (spa->spa_config_splitting != NULL)
431 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT,
432 spa->spa_config_splitting) == 0);
433 }
434
435 /*
436 * Add the top-level config. We even add this on pools which
437 * don't support holes in the namespace.
438 */
439 vdev_top_config_generate(spa, config);
440
441 /*
442 * If we're splitting, record the original pool's guid.
443 */
444 if (spa->spa_config_splitting != NULL &&
445 nvlist_lookup_uint64(spa->spa_config_splitting,
446 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) {
447 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID,
448 split_guid) == 0);
449 }
450
451 nvroot = vdev_config_generate(spa, vd, getstats, 0);
452 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
453 nvlist_free(nvroot);
454
455 /*
456 * Store what's necessary for reading the MOS in the label.
457 */
458 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
459 spa->spa_label_features) == 0);
460
461 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
462 ddt_histogram_t *ddh;
463 ddt_stat_t *dds;
464 ddt_object_t *ddo;
465
466 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
467 ddt_get_dedup_histogram(spa, ddh);
468 VERIFY(nvlist_add_uint64_array(config,
469 ZPOOL_CONFIG_DDT_HISTOGRAM,
470 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)) == 0);
471 kmem_free(ddh, sizeof (ddt_histogram_t));
472
473 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP);
474 ddt_get_dedup_object_stats(spa, ddo);
475 VERIFY(nvlist_add_uint64_array(config,
476 ZPOOL_CONFIG_DDT_OBJ_STATS,
477 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)) == 0);
478 kmem_free(ddo, sizeof (ddt_object_t));
479
480 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP);
481 ddt_get_dedup_stats(spa, dds);
482 VERIFY(nvlist_add_uint64_array(config,
483 ZPOOL_CONFIG_DDT_STATS,
484 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)) == 0);
485 kmem_free(dds, sizeof (ddt_stat_t));
486 }
487
488 if (locked)
489 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
490
491 return (config);
492 }
493
494 /*
495 * Update all disk labels, generate a fresh config based on the current
496 * in-core state, and sync the global config cache (do not sync the config
497 * cache if this is a booting rootpool).
498 */
499 void
spa_config_update(spa_t * spa,int what)500 spa_config_update(spa_t *spa, int what)
501 {
502 vdev_t *rvd = spa->spa_root_vdev;
503 uint64_t txg;
504 int c;
505
506 ASSERT(MUTEX_HELD(&spa_namespace_lock));
507
508 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
509 txg = spa_last_synced_txg(spa) + 1;
510 if (what == SPA_CONFIG_UPDATE_POOL) {
511 vdev_config_dirty(rvd);
512 } else {
513 /*
514 * If we have top-level vdevs that were added but have
515 * not yet been prepared for allocation, do that now.
516 * (It's safe now because the config cache is up to date,
517 * so it will be able to translate the new DVAs.)
518 * See comments in spa_vdev_add() for full details.
519 */
520 for (c = 0; c < rvd->vdev_children; c++) {
521 vdev_t *tvd = rvd->vdev_child[c];
522 if (tvd->vdev_ms_array == 0) {
523 vdev_ashift_optimize(tvd);
524 vdev_metaslab_set_size(tvd);
525 }
526 vdev_expand(tvd, txg);
527 }
528 }
529 spa_config_exit(spa, SCL_ALL, FTAG);
530
531 /*
532 * Wait for the mosconfig to be regenerated and synced.
533 */
534 txg_wait_synced(spa->spa_dsl_pool, txg);
535
536 /*
537 * Update the global config cache to reflect the new mosconfig.
538 */
539 if (!spa->spa_is_root)
540 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
541
542 if (what == SPA_CONFIG_UPDATE_POOL)
543 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
544 }
545