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 */
25
26 #include <sys/spa.h>
27 #include <sys/spa_impl.h>
28 #include <sys/nvpair.h>
29 #include <sys/uio.h>
30 #include <sys/fs/zfs.h>
31 #include <sys/vdev_impl.h>
32 #include <sys/zfs_ioctl.h>
33 #include <sys/utsname.h>
34 #include <sys/systeminfo.h>
35 #include <sys/sunddi.h>
36 #ifdef _KERNEL
37 #include <sys/kobj.h>
38 #include <sys/zone.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 char *pathname;
78 struct _buf *file;
79 uint64_t fsize;
80
81 /*
82 * Open the configuration file.
83 */
84 pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
85
86 (void) snprintf(pathname, MAXPATHLEN, "%s%s",
87 (rootdir != NULL) ? "./" : "", spa_config_path);
88
89 file = kobj_open_file(pathname);
90
91 kmem_free(pathname, MAXPATHLEN);
92
93 if (file == (struct _buf *)-1)
94 return;
95
96 if (kobj_get_filesize(file, &fsize) != 0)
97 goto out;
98
99 buf = kmem_alloc(fsize, KM_SLEEP);
100
101 /*
102 * Read the nvlist from the file.
103 */
104 if (kobj_read_file(file, buf, fsize, 0) < 0)
105 goto out;
106
107 /*
108 * Unpack the nvlist.
109 */
110 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)
111 goto out;
112
113 /*
114 * Iterate over all elements in the nvlist, creating a new spa_t for
115 * each one with the specified configuration.
116 */
117 mutex_enter(&spa_namespace_lock);
118 nvpair = NULL;
119 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {
120 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)
121 continue;
122
123 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0);
124
125 if (spa_lookup(nvpair_name(nvpair)) != NULL)
126 continue;
127 (void) spa_add(nvpair_name(nvpair), child, NULL);
128 }
129 mutex_exit(&spa_namespace_lock);
130
131 nvlist_free(nvlist);
132
133 out:
134 if (buf != NULL)
135 kmem_free(buf, fsize);
136
137 kobj_close_file(file);
138 }
139
140 static void
141 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
142 {
143 size_t buflen;
144 char *buf;
145 vnode_t *vp;
146 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
147 char *temp;
148
149 /*
150 * If the nvlist is empty (NULL), then remove the old cachefile.
151 */
152 if (nvl == NULL) {
153 (void) vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
154 return;
155 }
156
157 /*
158 * Pack the configuration into a buffer.
159 */
160 VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0);
161
162 buf = kmem_alloc(buflen, KM_SLEEP);
163 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
164
165 VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR,
166 KM_SLEEP) == 0);
167
168 /*
169 * Write the configuration to disk. We need to do the traditional
170 * 'write to temporary file, sync, move over original' to make sure we
171 * always have a consistent view of the data.
172 */
173 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);
174
175 if (vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) == 0) {
176 if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
177 0, RLIM64_INFINITY, kcred, NULL) == 0 &&
178 VOP_FSYNC(vp, FSYNC, kcred, NULL) == 0) {
179 (void) vn_rename(temp, dp->scd_path, UIO_SYSSPACE);
180 }
181 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
182 VN_RELE(vp);
183 }
184
185 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE);
186
187 kmem_free(buf, buflen);
188 kmem_free(temp, MAXPATHLEN);
189 }
190
191 /*
192 * Synchronize pool configuration to disk. This must be called with the
193 * namespace lock held.
194 */
195 void
196 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
197 {
198 spa_config_dirent_t *dp, *tdp;
199 nvlist_t *nvl;
200
201 ASSERT(MUTEX_HELD(&spa_namespace_lock));
202
203 if (rootdir == NULL || !(spa_mode_global & FWRITE))
204 return;
205
206 /*
207 * Iterate over all cachefiles for the pool, past or present. When the
208 * cachefile is changed, the new one is pushed onto this list, allowing
209 * us to update previous cachefiles that no longer contain this pool.
210 */
211 for (dp = list_head(&target->spa_config_list); dp != NULL;
212 dp = list_next(&target->spa_config_list, dp)) {
213 spa_t *spa = NULL;
214 if (dp->scd_path == NULL)
215 continue;
216
217 /*
218 * Iterate over all pools, adding any matching pools to 'nvl'.
219 */
220 nvl = NULL;
221 while ((spa = spa_next(spa)) != NULL) {
222 if (spa == target && removing)
223 continue;
224
225 mutex_enter(&spa->spa_props_lock);
226 tdp = list_head(&spa->spa_config_list);
227 if (spa->spa_config == NULL ||
228 tdp->scd_path == NULL ||
229 strcmp(tdp->scd_path, dp->scd_path) != 0) {
230 mutex_exit(&spa->spa_props_lock);
231 continue;
232 }
233
234 if (nvl == NULL)
235 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME,
236 KM_SLEEP) == 0);
237
238 VERIFY(nvlist_add_nvlist(nvl, spa->spa_name,
239 spa->spa_config) == 0);
240 mutex_exit(&spa->spa_props_lock);
241 }
242
243 spa_config_write(dp, nvl);
244 nvlist_free(nvl);
245 }
246
247 /*
248 * Remove any config entries older than the current one.
249 */
250 dp = list_head(&target->spa_config_list);
251 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {
252 list_remove(&target->spa_config_list, tdp);
253 if (tdp->scd_path != NULL)
254 spa_strfree(tdp->scd_path);
255 kmem_free(tdp, sizeof (spa_config_dirent_t));
256 }
257
258 spa_config_generation++;
259
260 if (postsysevent)
261 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC);
262 }
263
264 /*
265 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache,
266 * and we don't want to allow the local zone to see all the pools anyway.
267 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration
268 * information for all pool visible within the zone.
269 */
270 nvlist_t *
271 spa_all_configs(uint64_t *generation)
272 {
273 nvlist_t *pools;
274 spa_t *spa = NULL;
275
276 if (*generation == spa_config_generation)
277 return (NULL);
278
279 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);
280
281 mutex_enter(&spa_namespace_lock);
282 while ((spa = spa_next(spa)) != NULL) {
283 if (INGLOBALZONE(curproc) ||
284 zone_dataset_visible(spa_name(spa), NULL)) {
285 mutex_enter(&spa->spa_props_lock);
286 VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
287 spa->spa_config) == 0);
288 mutex_exit(&spa->spa_props_lock);
289 }
290 }
291 *generation = spa_config_generation;
292 mutex_exit(&spa_namespace_lock);
293
294 return (pools);
295 }
296
297 void
298 spa_config_set(spa_t *spa, nvlist_t *config)
299 {
300 mutex_enter(&spa->spa_props_lock);
301 if (spa->spa_config != NULL)
302 nvlist_free(spa->spa_config);
303 spa->spa_config = config;
304 mutex_exit(&spa->spa_props_lock);
305 }
306
307 /*
308 * Generate the pool's configuration based on the current in-core state.
309 * We infer whether to generate a complete config or just one top-level config
310 * based on whether vd is the root vdev.
311 */
312 nvlist_t *
313 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
314 {
315 nvlist_t *config, *nvroot;
316 vdev_t *rvd = spa->spa_root_vdev;
317 unsigned long hostid = 0;
318 boolean_t locked = B_FALSE;
319 uint64_t split_guid;
320
321 if (vd == NULL) {
322 vd = rvd;
323 locked = B_TRUE;
324 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
325 }
326
327 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==
328 (SCL_CONFIG | SCL_STATE));
329
330 /*
331 * If txg is -1, report the current value of spa->spa_config_txg.
332 */
333 if (txg == -1ULL)
334 txg = spa->spa_config_txg;
335
336 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);
337
338 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
339 spa_version(spa)) == 0);
340 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
341 spa_name(spa)) == 0);
342 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
343 spa_state(spa)) == 0);
344 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
345 txg) == 0);
346 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
347 spa_guid(spa)) == 0);
348 #ifdef _KERNEL
349 hostid = zone_get_hostid(NULL);
350 #else /* _KERNEL */
351 /*
352 * We're emulating the system's hostid in userland, so we can't use
353 * zone_get_hostid().
354 */
355 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid);
356 #endif /* _KERNEL */
357 if (hostid != 0) {
358 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
359 hostid) == 0);
360 }
361 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
362 utsname.nodename) == 0);
363
364 if (vd != rvd) {
365 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
366 vd->vdev_top->vdev_guid) == 0);
367 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
368 vd->vdev_guid) == 0);
369 if (vd->vdev_isspare)
370 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,
371 1ULL) == 0);
372 if (vd->vdev_islog)
373 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,
374 1ULL) == 0);
375 vd = vd->vdev_top; /* label contains top config */
376 } else {
377 /*
378 * Only add the (potentially large) split information
379 * in the mos config, and not in the vdev labels
380 */
381 if (spa->spa_config_splitting != NULL)
382 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT,
383 spa->spa_config_splitting) == 0);
384 }
385
386 /*
387 * Add the top-level config. We even add this on pools which
388 * don't support holes in the namespace.
389 */
390 vdev_top_config_generate(spa, config);
391
392 /*
393 * If we're splitting, record the original pool's guid.
394 */
395 if (spa->spa_config_splitting != NULL &&
396 nvlist_lookup_uint64(spa->spa_config_splitting,
397 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) {
398 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID,
399 split_guid) == 0);
400 }
401
402 nvroot = vdev_config_generate(spa, vd, getstats, 0);
403 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
404 nvlist_free(nvroot);
405
406 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
407 ddt_histogram_t *ddh;
408 ddt_stat_t *dds;
409 ddt_object_t *ddo;
410
411 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
412 ddt_get_dedup_histogram(spa, ddh);
413 VERIFY(nvlist_add_uint64_array(config,
414 ZPOOL_CONFIG_DDT_HISTOGRAM,
415 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)) == 0);
416 kmem_free(ddh, sizeof (ddt_histogram_t));
417
418 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP);
419 ddt_get_dedup_object_stats(spa, ddo);
420 VERIFY(nvlist_add_uint64_array(config,
421 ZPOOL_CONFIG_DDT_OBJ_STATS,
422 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)) == 0);
423 kmem_free(ddo, sizeof (ddt_object_t));
424
425 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP);
426 ddt_get_dedup_stats(spa, dds);
427 VERIFY(nvlist_add_uint64_array(config,
428 ZPOOL_CONFIG_DDT_STATS,
429 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)) == 0);
430 kmem_free(dds, sizeof (ddt_stat_t));
431 }
432
433 if (locked)
434 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
435
436 return (config);
437 }
438
439 /*
440 * Update all disk labels, generate a fresh config based on the current
441 * in-core state, and sync the global config cache (do not sync the config
442 * cache if this is a booting rootpool).
443 */
444 void
445 spa_config_update(spa_t *spa, int what)
446 {
447 vdev_t *rvd = spa->spa_root_vdev;
448 uint64_t txg;
449 int c;
450
451 ASSERT(MUTEX_HELD(&spa_namespace_lock));
452
453 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
454 txg = spa_last_synced_txg(spa) + 1;
455 if (what == SPA_CONFIG_UPDATE_POOL) {
456 vdev_config_dirty(rvd);
457 } else {
458 /*
459 * If we have top-level vdevs that were added but have
460 * not yet been prepared for allocation, do that now.
461 * (It's safe now because the config cache is up to date,
462 * so it will be able to translate the new DVAs.)
463 * See comments in spa_vdev_add() for full details.
464 */
465 for (c = 0; c < rvd->vdev_children; c++) {
466 vdev_t *tvd = rvd->vdev_child[c];
467 if (tvd->vdev_ms_array == 0)
468 vdev_metaslab_set_size(tvd);
469 vdev_expand(tvd, txg);
470 }
471 }
472 spa_config_exit(spa, SCL_ALL, FTAG);
473
474 /*
475 * Wait for the mosconfig to be regenerated and synced.
476 */
477 txg_wait_synced(spa->spa_dsl_pool, txg);
478
479 /*
480 * Update the global config cache to reflect the new mosconfig.
481 */
482 if (!spa->spa_is_root)
483 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
484
485 if (what == SPA_CONFIG_UPDATE_POOL)
486 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
487 }