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 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25 */
26
27 #include <sys/zfs_context.h>
28 #include <sys/spa_impl.h>
29 #include <sys/spa_boot.h>
30 #include <sys/zio.h>
31 #include <sys/zio_checksum.h>
32 #include <sys/zio_compress.h>
33 #include <sys/dmu.h>
34 #include <sys/dmu_tx.h>
35 #include <sys/zap.h>
36 #include <sys/zil.h>
37 #include <sys/vdev_impl.h>
38 #include <sys/metaslab.h>
39 #include <sys/uberblock_impl.h>
40 #include <sys/txg.h>
41 #include <sys/avl.h>
42 #include <sys/unique.h>
43 #include <sys/dsl_pool.h>
44 #include <sys/dsl_dir.h>
45 #include <sys/dsl_prop.h>
46 #include <sys/dsl_scan.h>
47 #include <sys/fs/zfs.h>
48 #include <sys/metaslab_impl.h>
49 #include <sys/arc.h>
50 #include <sys/ddt.h>
51 #include "zfs_prop.h"
52 #include "zfeature_common.h"
53
54 /*
55 * SPA locking
56 *
57 * There are four basic locks for managing spa_t structures:
58 *
59 * spa_namespace_lock (global mutex)
60 *
61 * This lock must be acquired to do any of the following:
62 *
63 * - Lookup a spa_t by name
64 * - Add or remove a spa_t from the namespace
65 * - Increase spa_refcount from non-zero
66 * - Check if spa_refcount is zero
67 * - Rename a spa_t
68 * - add/remove/attach/detach devices
69 * - Held for the duration of create/destroy/import/export
70 *
71 * It does not need to handle recursion. A create or destroy may
72 * reference objects (files or zvols) in other pools, but by
73 * definition they must have an existing reference, and will never need
74 * to lookup a spa_t by name.
75 *
76 * spa_refcount (per-spa refcount_t protected by mutex)
77 *
78 * This reference count keep track of any active users of the spa_t. The
79 * spa_t cannot be destroyed or freed while this is non-zero. Internally,
80 * the refcount is never really 'zero' - opening a pool implicitly keeps
81 * some references in the DMU. Internally we check against spa_minref, but
82 * present the image of a zero/non-zero value to consumers.
83 *
84 * spa_config_lock[] (per-spa array of rwlocks)
85 *
86 * This protects the spa_t from config changes, and must be held in
87 * the following circumstances:
88 *
89 * - RW_READER to perform I/O to the spa
90 * - RW_WRITER to change the vdev config
91 *
92 * The locking order is fairly straightforward:
93 *
94 * spa_namespace_lock -> spa_refcount
95 *
96 * The namespace lock must be acquired to increase the refcount from 0
97 * or to check if it is zero.
98 *
99 * spa_refcount -> spa_config_lock[]
100 *
101 * There must be at least one valid reference on the spa_t to acquire
102 * the config lock.
103 *
104 * spa_namespace_lock -> spa_config_lock[]
105 *
106 * The namespace lock must always be taken before the config lock.
107 *
108 *
109 * The spa_namespace_lock can be acquired directly and is globally visible.
110 *
111 * The namespace is manipulated using the following functions, all of which
112 * require the spa_namespace_lock to be held.
113 *
114 * spa_lookup() Lookup a spa_t by name.
115 *
116 * spa_add() Create a new spa_t in the namespace.
117 *
118 * spa_remove() Remove a spa_t from the namespace. This also
119 * frees up any memory associated with the spa_t.
120 *
121 * spa_next() Returns the next spa_t in the system, or the
122 * first if NULL is passed.
123 *
124 * spa_evict_all() Shutdown and remove all spa_t structures in
125 * the system.
126 *
127 * spa_guid_exists() Determine whether a pool/device guid exists.
128 *
129 * The spa_refcount is manipulated using the following functions:
130 *
131 * spa_open_ref() Adds a reference to the given spa_t. Must be
132 * called with spa_namespace_lock held if the
133 * refcount is currently zero.
134 *
135 * spa_close() Remove a reference from the spa_t. This will
136 * not free the spa_t or remove it from the
137 * namespace. No locking is required.
138 *
139 * spa_refcount_zero() Returns true if the refcount is currently
140 * zero. Must be called with spa_namespace_lock
141 * held.
142 *
143 * The spa_config_lock[] is an array of rwlocks, ordered as follows:
144 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
145 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
146 *
147 * To read the configuration, it suffices to hold one of these locks as reader.
148 * To modify the configuration, you must hold all locks as writer. To modify
149 * vdev state without altering the vdev tree's topology (e.g. online/offline),
150 * you must hold SCL_STATE and SCL_ZIO as writer.
151 *
152 * We use these distinct config locks to avoid recursive lock entry.
153 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
154 * block allocations (SCL_ALLOC), which may require reading space maps
155 * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
156 *
157 * The spa config locks cannot be normal rwlocks because we need the
158 * ability to hand off ownership. For example, SCL_ZIO is acquired
159 * by the issuing thread and later released by an interrupt thread.
160 * They do, however, obey the usual write-wanted semantics to prevent
161 * writer (i.e. system administrator) starvation.
162 *
163 * The lock acquisition rules are as follows:
164 *
165 * SCL_CONFIG
166 * Protects changes to the vdev tree topology, such as vdev
167 * add/remove/attach/detach. Protects the dirty config list
168 * (spa_config_dirty_list) and the set of spares and l2arc devices.
169 *
170 * SCL_STATE
171 * Protects changes to pool state and vdev state, such as vdev
172 * online/offline/fault/degrade/clear. Protects the dirty state list
173 * (spa_state_dirty_list) and global pool state (spa_state).
174 *
175 * SCL_ALLOC
176 * Protects changes to metaslab groups and classes.
177 * Held as reader by metaslab_alloc() and metaslab_claim().
178 *
179 * SCL_ZIO
180 * Held by bp-level zios (those which have no io_vd upon entry)
181 * to prevent changes to the vdev tree. The bp-level zio implicitly
182 * protects all of its vdev child zios, which do not hold SCL_ZIO.
183 *
184 * SCL_FREE
185 * Protects changes to metaslab groups and classes.
186 * Held as reader by metaslab_free(). SCL_FREE is distinct from
187 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
188 * blocks in zio_done() while another i/o that holds either
189 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
190 *
191 * SCL_VDEV
192 * Held as reader to prevent changes to the vdev tree during trivial
193 * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the
194 * other locks, and lower than all of them, to ensure that it's safe
195 * to acquire regardless of caller context.
196 *
197 * In addition, the following rules apply:
198 *
199 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list.
200 * The lock ordering is SCL_CONFIG > spa_props_lock.
201 *
202 * (b) I/O operations on leaf vdevs. For any zio operation that takes
203 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
204 * or zio_write_phys() -- the caller must ensure that the config cannot
205 * cannot change in the interim, and that the vdev cannot be reopened.
206 * SCL_STATE as reader suffices for both.
207 *
208 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
209 *
210 * spa_vdev_enter() Acquire the namespace lock and the config lock
211 * for writing.
212 *
213 * spa_vdev_exit() Release the config lock, wait for all I/O
214 * to complete, sync the updated configs to the
215 * cache, and release the namespace lock.
216 *
217 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
218 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
219 * locking is, always, based on spa_namespace_lock and spa_config_lock[].
220 *
221 * spa_rename() is also implemented within this file since it requires
222 * manipulation of the namespace.
223 */
224
225 static avl_tree_t spa_namespace_avl;
226 kmutex_t spa_namespace_lock;
227 static kcondvar_t spa_namespace_cv;
228 static int spa_active_count;
229 int spa_max_replication_override = SPA_DVAS_PER_BP;
230
231 static kmutex_t spa_spare_lock;
232 static avl_tree_t spa_spare_avl;
233 static kmutex_t spa_l2cache_lock;
234 static avl_tree_t spa_l2cache_avl;
235
236 kmem_cache_t *spa_buffer_pool;
237 int spa_mode_global;
238
239 #ifdef ZFS_DEBUG
240 /* Everything except dprintf and spa is on by default in debug builds */
241 int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA);
242 #else
243 int zfs_flags = 0;
244 #endif
245
246 /*
247 * zfs_recover can be set to nonzero to attempt to recover from
248 * otherwise-fatal errors, typically caused by on-disk corruption. When
249 * set, calls to zfs_panic_recover() will turn into warning messages.
250 * This should only be used as a last resort, as it typically results
251 * in leaked space, or worse.
252 */
253 boolean_t zfs_recover = B_FALSE;
254
255 /*
256 * If destroy encounters an EIO while reading metadata (e.g. indirect
257 * blocks), space referenced by the missing metadata can not be freed.
258 * Normally this causes the background destroy to become "stalled", as
259 * it is unable to make forward progress. While in this stalled state,
260 * all remaining space to free from the error-encountering filesystem is
261 * "temporarily leaked". Set this flag to cause it to ignore the EIO,
262 * permanently leak the space from indirect blocks that can not be read,
263 * and continue to free everything else that it can.
264 *
265 * The default, "stalling" behavior is useful if the storage partially
266 * fails (i.e. some but not all i/os fail), and then later recovers. In
267 * this case, we will be able to continue pool operations while it is
268 * partially failed, and when it recovers, we can continue to free the
269 * space, with no leaks. However, note that this case is actually
270 * fairly rare.
271 *
272 * Typically pools either (a) fail completely (but perhaps temporarily,
273 * e.g. a top-level vdev going offline), or (b) have localized,
274 * permanent errors (e.g. disk returns the wrong data due to bit flip or
275 * firmware bug). In case (a), this setting does not matter because the
276 * pool will be suspended and the sync thread will not be able to make
277 * forward progress regardless. In case (b), because the error is
278 * permanent, the best we can do is leak the minimum amount of space,
279 * which is what setting this flag will do. Therefore, it is reasonable
280 * for this flag to normally be set, but we chose the more conservative
281 * approach of not setting it, so that there is no possibility of
282 * leaking space in the "partial temporary" failure case.
283 */
284 boolean_t zfs_free_leak_on_eio = B_FALSE;
285
286 /*
287 * Expiration time in milliseconds. This value has two meanings. First it is
288 * used to determine when the spa_deadman() logic should fire. By default the
289 * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds.
290 * Secondly, the value determines if an I/O is considered "hung". Any I/O that
291 * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting
292 * in a system panic.
293 */
294 uint64_t zfs_deadman_synctime_ms = 1000000ULL;
295
296 /*
297 * Check time in milliseconds. This defines the frequency at which we check
298 * for hung I/O.
299 */
300 uint64_t zfs_deadman_checktime_ms = 5000ULL;
301
302 /*
303 * Override the zfs deadman behavior via /etc/system. By default the
304 * deadman is enabled except on VMware and sparc deployments.
305 */
306 int zfs_deadman_enabled = -1;
307
308 /*
309 * The worst case is single-sector max-parity RAID-Z blocks, in which
310 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
311 * times the size; so just assume that. Add to this the fact that
312 * we can have up to 3 DVAs per bp, and one more factor of 2 because
313 * the block may be dittoed with up to 3 DVAs by ddt_sync(). All together,
314 * the worst case is:
315 * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24
316 */
317 int spa_asize_inflation = 24;
318
319 /*
320 * ==========================================================================
321 * SPA config locking
322 * ==========================================================================
323 */
324 static void
325 spa_config_lock_init(spa_t *spa)
326 {
327 for (int i = 0; i < SCL_LOCKS; i++) {
328 spa_config_lock_t *scl = &spa->spa_config_lock[i];
329 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
330 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
331 refcount_create_untracked(&scl->scl_count);
332 scl->scl_writer = NULL;
333 scl->scl_write_wanted = 0;
334 }
335 }
336
337 static void
338 spa_config_lock_destroy(spa_t *spa)
339 {
340 for (int i = 0; i < SCL_LOCKS; i++) {
341 spa_config_lock_t *scl = &spa->spa_config_lock[i];
342 mutex_destroy(&scl->scl_lock);
343 cv_destroy(&scl->scl_cv);
344 refcount_destroy(&scl->scl_count);
345 ASSERT(scl->scl_writer == NULL);
346 ASSERT(scl->scl_write_wanted == 0);
347 }
348 }
349
350 int
351 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
352 {
353 for (int i = 0; i < SCL_LOCKS; i++) {
354 spa_config_lock_t *scl = &spa->spa_config_lock[i];
355 if (!(locks & (1 << i)))
356 continue;
357 mutex_enter(&scl->scl_lock);
358 if (rw == RW_READER) {
359 if (scl->scl_writer || scl->scl_write_wanted) {
360 mutex_exit(&scl->scl_lock);
361 spa_config_exit(spa, locks ^ (1 << i), tag);
362 return (0);
363 }
364 } else {
365 ASSERT(scl->scl_writer != curthread);
366 if (!refcount_is_zero(&scl->scl_count)) {
367 mutex_exit(&scl->scl_lock);
368 spa_config_exit(spa, locks ^ (1 << i), tag);
369 return (0);
370 }
371 scl->scl_writer = curthread;
372 }
373 (void) refcount_add(&scl->scl_count, tag);
374 mutex_exit(&scl->scl_lock);
375 }
376 return (1);
377 }
378
379 void
380 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
381 {
382 int wlocks_held = 0;
383
384 ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY);
385
386 for (int i = 0; i < SCL_LOCKS; i++) {
387 spa_config_lock_t *scl = &spa->spa_config_lock[i];
388 if (scl->scl_writer == curthread)
389 wlocks_held |= (1 << i);
390 if (!(locks & (1 << i)))
391 continue;
392 mutex_enter(&scl->scl_lock);
393 if (rw == RW_READER) {
394 while (scl->scl_writer || scl->scl_write_wanted) {
395 cv_wait(&scl->scl_cv, &scl->scl_lock);
396 }
397 } else {
398 ASSERT(scl->scl_writer != curthread);
399 while (!refcount_is_zero(&scl->scl_count)) {
400 scl->scl_write_wanted++;
401 cv_wait(&scl->scl_cv, &scl->scl_lock);
402 scl->scl_write_wanted--;
403 }
404 scl->scl_writer = curthread;
405 }
406 (void) refcount_add(&scl->scl_count, tag);
407 mutex_exit(&scl->scl_lock);
408 }
409 ASSERT(wlocks_held <= locks);
410 }
411
412 void
413 spa_config_exit(spa_t *spa, int locks, void *tag)
414 {
415 for (int i = SCL_LOCKS - 1; i >= 0; i--) {
416 spa_config_lock_t *scl = &spa->spa_config_lock[i];
417 if (!(locks & (1 << i)))
418 continue;
419 mutex_enter(&scl->scl_lock);
420 ASSERT(!refcount_is_zero(&scl->scl_count));
421 if (refcount_remove(&scl->scl_count, tag) == 0) {
422 ASSERT(scl->scl_writer == NULL ||
423 scl->scl_writer == curthread);
424 scl->scl_writer = NULL; /* OK in either case */
425 cv_broadcast(&scl->scl_cv);
426 }
427 mutex_exit(&scl->scl_lock);
428 }
429 }
430
431 int
432 spa_config_held(spa_t *spa, int locks, krw_t rw)
433 {
434 int locks_held = 0;
435
436 for (int i = 0; i < SCL_LOCKS; i++) {
437 spa_config_lock_t *scl = &spa->spa_config_lock[i];
438 if (!(locks & (1 << i)))
439 continue;
440 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
441 (rw == RW_WRITER && scl->scl_writer == curthread))
442 locks_held |= 1 << i;
443 }
444
445 return (locks_held);
446 }
447
448 /*
449 * ==========================================================================
450 * SPA namespace functions
451 * ==========================================================================
452 */
453
454 /*
455 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held.
456 * Returns NULL if no matching spa_t is found.
457 */
458 spa_t *
459 spa_lookup(const char *name)
460 {
461 static spa_t search; /* spa_t is large; don't allocate on stack */
462 spa_t *spa;
463 avl_index_t where;
464 char *cp;
465
466 ASSERT(MUTEX_HELD(&spa_namespace_lock));
467
468 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
469
470 /*
471 * If it's a full dataset name, figure out the pool name and
472 * just use that.
473 */
474 cp = strpbrk(search.spa_name, "/@#");
475 if (cp != NULL)
476 *cp = '\0';
477
478 spa = avl_find(&spa_namespace_avl, &search, &where);
479
480 return (spa);
481 }
482
483 /*
484 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms.
485 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues
486 * looking for potentially hung I/Os.
487 */
488 void
489 spa_deadman(void *arg)
490 {
491 spa_t *spa = arg;
492
493 /*
494 * Disable the deadman timer if the pool is suspended.
495 */
496 if (spa_suspended(spa)) {
497 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
498 return;
499 }
500
501 zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu",
502 (gethrtime() - spa->spa_sync_starttime) / NANOSEC,
503 ++spa->spa_deadman_calls);
504 if (zfs_deadman_enabled)
505 vdev_deadman(spa->spa_root_vdev);
506 }
507
508 /*
509 * Create an uninitialized spa_t with the given name. Requires
510 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already
511 * exist by calling spa_lookup() first.
512 */
513 spa_t *
514 spa_add(const char *name, nvlist_t *config, const char *altroot)
515 {
516 spa_t *spa;
517 spa_config_dirent_t *dp;
518 cyc_handler_t hdlr;
519 cyc_time_t when;
520
521 ASSERT(MUTEX_HELD(&spa_namespace_lock));
522
523 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
524
525 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
526 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
527 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
528 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
529 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL);
530 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
531 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
532 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
533 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL);
534 mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL);
535
536 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
537 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL);
538 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
539 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
540
541 for (int t = 0; t < TXG_SIZE; t++)
542 bplist_create(&spa->spa_free_bplist[t]);
543
544 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
545 spa->spa_state = POOL_STATE_UNINITIALIZED;
546 spa->spa_freeze_txg = UINT64_MAX;
547 spa->spa_final_txg = UINT64_MAX;
548 spa->spa_load_max_txg = UINT64_MAX;
549 spa->spa_proc = &p0;
550 spa->spa_proc_state = SPA_PROC_NONE;
551
552 hdlr.cyh_func = spa_deadman;
553 hdlr.cyh_arg = spa;
554 hdlr.cyh_level = CY_LOW_LEVEL;
555
556 spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms);
557
558 /*
559 * This determines how often we need to check for hung I/Os after
560 * the cyclic has already fired. Since checking for hung I/Os is
561 * an expensive operation we don't want to check too frequently.
562 * Instead wait for 5 seconds before checking again.
563 */
564 when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms);
565 when.cyt_when = CY_INFINITY;
566 mutex_enter(&cpu_lock);
567 spa->spa_deadman_cycid = cyclic_add(&hdlr, &when);
568 mutex_exit(&cpu_lock);
569
570 refcount_create(&spa->spa_refcount);
571 spa_config_lock_init(spa);
572
573 avl_add(&spa_namespace_avl, spa);
574
575 /*
576 * Set the alternate root, if there is one.
577 */
578 if (altroot) {
579 spa->spa_root = spa_strdup(altroot);
580 spa_active_count++;
581 }
582
583 /*
584 * Every pool starts with the default cachefile
585 */
586 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
587 offsetof(spa_config_dirent_t, scd_link));
588
589 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
590 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
591 list_insert_head(&spa->spa_config_list, dp);
592
593 VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME,
594 KM_SLEEP) == 0);
595
596 if (config != NULL) {
597 nvlist_t *features;
598
599 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
600 &features) == 0) {
601 VERIFY(nvlist_dup(features, &spa->spa_label_features,
602 0) == 0);
603 }
604
605 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
606 }
607
608 if (spa->spa_label_features == NULL) {
609 VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME,
610 KM_SLEEP) == 0);
611 }
612
613 spa->spa_iokstat = kstat_create("zfs", 0, name,
614 "disk", KSTAT_TYPE_IO, 1, 0);
615 if (spa->spa_iokstat) {
616 spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock;
617 kstat_install(spa->spa_iokstat);
618 }
619
620 spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0);
621
622 /*
623 * As a pool is being created, treat all features as disabled by
624 * setting SPA_FEATURE_DISABLED for all entries in the feature
625 * refcount cache.
626 */
627 for (int i = 0; i < SPA_FEATURES; i++) {
628 spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED;
629 }
630
631 return (spa);
632 }
633
634 /*
635 * Removes a spa_t from the namespace, freeing up any memory used. Requires
636 * spa_namespace_lock. This is called only after the spa_t has been closed and
637 * deactivated.
638 */
639 void
640 spa_remove(spa_t *spa)
641 {
642 spa_config_dirent_t *dp;
643
644 ASSERT(MUTEX_HELD(&spa_namespace_lock));
645 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
646
647 nvlist_free(spa->spa_config_splitting);
648
649 avl_remove(&spa_namespace_avl, spa);
650 cv_broadcast(&spa_namespace_cv);
651
652 if (spa->spa_root) {
653 spa_strfree(spa->spa_root);
654 spa_active_count--;
655 }
656
657 while ((dp = list_head(&spa->spa_config_list)) != NULL) {
658 list_remove(&spa->spa_config_list, dp);
659 if (dp->scd_path != NULL)
660 spa_strfree(dp->scd_path);
661 kmem_free(dp, sizeof (spa_config_dirent_t));
662 }
663
664 list_destroy(&spa->spa_config_list);
665
666 nvlist_free(spa->spa_label_features);
667 nvlist_free(spa->spa_load_info);
668 spa_config_set(spa, NULL);
669
670 mutex_enter(&cpu_lock);
671 if (spa->spa_deadman_cycid != CYCLIC_NONE)
672 cyclic_remove(spa->spa_deadman_cycid);
673 mutex_exit(&cpu_lock);
674 spa->spa_deadman_cycid = CYCLIC_NONE;
675
676 refcount_destroy(&spa->spa_refcount);
677
678 spa_config_lock_destroy(spa);
679
680 kstat_delete(spa->spa_iokstat);
681 spa->spa_iokstat = NULL;
682
683 for (int t = 0; t < TXG_SIZE; t++)
684 bplist_destroy(&spa->spa_free_bplist[t]);
685
686 cv_destroy(&spa->spa_async_cv);
687 cv_destroy(&spa->spa_proc_cv);
688 cv_destroy(&spa->spa_scrub_io_cv);
689 cv_destroy(&spa->spa_suspend_cv);
690
691 mutex_destroy(&spa->spa_async_lock);
692 mutex_destroy(&spa->spa_errlist_lock);
693 mutex_destroy(&spa->spa_errlog_lock);
694 mutex_destroy(&spa->spa_history_lock);
695 mutex_destroy(&spa->spa_proc_lock);
696 mutex_destroy(&spa->spa_props_lock);
697 mutex_destroy(&spa->spa_scrub_lock);
698 mutex_destroy(&spa->spa_suspend_lock);
699 mutex_destroy(&spa->spa_vdev_top_lock);
700 mutex_destroy(&spa->spa_iokstat_lock);
701
702 kmem_free(spa, sizeof (spa_t));
703 }
704
705 /*
706 * Given a pool, return the next pool in the namespace, or NULL if there is
707 * none. If 'prev' is NULL, return the first pool.
708 */
709 spa_t *
710 spa_next(spa_t *prev)
711 {
712 ASSERT(MUTEX_HELD(&spa_namespace_lock));
713
714 if (prev)
715 return (AVL_NEXT(&spa_namespace_avl, prev));
716 else
717 return (avl_first(&spa_namespace_avl));
718 }
719
720 /*
721 * ==========================================================================
722 * SPA refcount functions
723 * ==========================================================================
724 */
725
726 /*
727 * Add a reference to the given spa_t. Must have at least one reference, or
728 * have the namespace lock held.
729 */
730 void
731 spa_open_ref(spa_t *spa, void *tag)
732 {
733 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
734 MUTEX_HELD(&spa_namespace_lock));
735 (void) refcount_add(&spa->spa_refcount, tag);
736 }
737
738 /*
739 * Remove a reference to the given spa_t. Must have at least one reference, or
740 * have the namespace lock held.
741 */
742 void
743 spa_close(spa_t *spa, void *tag)
744 {
745 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
746 MUTEX_HELD(&spa_namespace_lock));
747 (void) refcount_remove(&spa->spa_refcount, tag);
748 }
749
750 /*
751 * Check to see if the spa refcount is zero. Must be called with
752 * spa_namespace_lock held. We really compare against spa_minref, which is the
753 * number of references acquired when opening a pool
754 */
755 boolean_t
756 spa_refcount_zero(spa_t *spa)
757 {
758 ASSERT(MUTEX_HELD(&spa_namespace_lock));
759
760 return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
761 }
762
763 /*
764 * ==========================================================================
765 * SPA spare and l2cache tracking
766 * ==========================================================================
767 */
768
769 /*
770 * Hot spares and cache devices are tracked using the same code below,
771 * for 'auxiliary' devices.
772 */
773
774 typedef struct spa_aux {
775 uint64_t aux_guid;
776 uint64_t aux_pool;
777 avl_node_t aux_avl;
778 int aux_count;
779 } spa_aux_t;
780
781 static int
782 spa_aux_compare(const void *a, const void *b)
783 {
784 const spa_aux_t *sa = a;
785 const spa_aux_t *sb = b;
786
787 if (sa->aux_guid < sb->aux_guid)
788 return (-1);
789 else if (sa->aux_guid > sb->aux_guid)
790 return (1);
791 else
792 return (0);
793 }
794
795 void
796 spa_aux_add(vdev_t *vd, avl_tree_t *avl)
797 {
798 avl_index_t where;
799 spa_aux_t search;
800 spa_aux_t *aux;
801
802 search.aux_guid = vd->vdev_guid;
803 if ((aux = avl_find(avl, &search, &where)) != NULL) {
804 aux->aux_count++;
805 } else {
806 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
807 aux->aux_guid = vd->vdev_guid;
808 aux->aux_count = 1;
809 avl_insert(avl, aux, where);
810 }
811 }
812
813 void
814 spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
815 {
816 spa_aux_t search;
817 spa_aux_t *aux;
818 avl_index_t where;
819
820 search.aux_guid = vd->vdev_guid;
821 aux = avl_find(avl, &search, &where);
822
823 ASSERT(aux != NULL);
824
825 if (--aux->aux_count == 0) {
826 avl_remove(avl, aux);
827 kmem_free(aux, sizeof (spa_aux_t));
828 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
829 aux->aux_pool = 0ULL;
830 }
831 }
832
833 boolean_t
834 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
835 {
836 spa_aux_t search, *found;
837
838 search.aux_guid = guid;
839 found = avl_find(avl, &search, NULL);
840
841 if (pool) {
842 if (found)
843 *pool = found->aux_pool;
844 else
845 *pool = 0ULL;
846 }
847
848 if (refcnt) {
849 if (found)
850 *refcnt = found->aux_count;
851 else
852 *refcnt = 0;
853 }
854
855 return (found != NULL);
856 }
857
858 void
859 spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
860 {
861 spa_aux_t search, *found;
862 avl_index_t where;
863
864 search.aux_guid = vd->vdev_guid;
865 found = avl_find(avl, &search, &where);
866 ASSERT(found != NULL);
867 ASSERT(found->aux_pool == 0ULL);
868
869 found->aux_pool = spa_guid(vd->vdev_spa);
870 }
871
872 /*
873 * Spares are tracked globally due to the following constraints:
874 *
875 * - A spare may be part of multiple pools.
876 * - A spare may be added to a pool even if it's actively in use within
877 * another pool.
878 * - A spare in use in any pool can only be the source of a replacement if
879 * the target is a spare in the same pool.
880 *
881 * We keep track of all spares on the system through the use of a reference
882 * counted AVL tree. When a vdev is added as a spare, or used as a replacement
883 * spare, then we bump the reference count in the AVL tree. In addition, we set
884 * the 'vdev_isspare' member to indicate that the device is a spare (active or
885 * inactive). When a spare is made active (used to replace a device in the
886 * pool), we also keep track of which pool its been made a part of.
887 *
888 * The 'spa_spare_lock' protects the AVL tree. These functions are normally
889 * called under the spa_namespace lock as part of vdev reconfiguration. The
890 * separate spare lock exists for the status query path, which does not need to
891 * be completely consistent with respect to other vdev configuration changes.
892 */
893
894 static int
895 spa_spare_compare(const void *a, const void *b)
896 {
897 return (spa_aux_compare(a, b));
898 }
899
900 void
901 spa_spare_add(vdev_t *vd)
902 {
903 mutex_enter(&spa_spare_lock);
904 ASSERT(!vd->vdev_isspare);
905 spa_aux_add(vd, &spa_spare_avl);
906 vd->vdev_isspare = B_TRUE;
907 mutex_exit(&spa_spare_lock);
908 }
909
910 void
911 spa_spare_remove(vdev_t *vd)
912 {
913 mutex_enter(&spa_spare_lock);
914 ASSERT(vd->vdev_isspare);
915 spa_aux_remove(vd, &spa_spare_avl);
916 vd->vdev_isspare = B_FALSE;
917 mutex_exit(&spa_spare_lock);
918 }
919
920 boolean_t
921 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
922 {
923 boolean_t found;
924
925 mutex_enter(&spa_spare_lock);
926 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
927 mutex_exit(&spa_spare_lock);
928
929 return (found);
930 }
931
932 void
933 spa_spare_activate(vdev_t *vd)
934 {
935 mutex_enter(&spa_spare_lock);
936 ASSERT(vd->vdev_isspare);
937 spa_aux_activate(vd, &spa_spare_avl);
938 mutex_exit(&spa_spare_lock);
939 }
940
941 /*
942 * Level 2 ARC devices are tracked globally for the same reasons as spares.
943 * Cache devices currently only support one pool per cache device, and so
944 * for these devices the aux reference count is currently unused beyond 1.
945 */
946
947 static int
948 spa_l2cache_compare(const void *a, const void *b)
949 {
950 return (spa_aux_compare(a, b));
951 }
952
953 void
954 spa_l2cache_add(vdev_t *vd)
955 {
956 mutex_enter(&spa_l2cache_lock);
957 ASSERT(!vd->vdev_isl2cache);
958 spa_aux_add(vd, &spa_l2cache_avl);
959 vd->vdev_isl2cache = B_TRUE;
960 mutex_exit(&spa_l2cache_lock);
961 }
962
963 void
964 spa_l2cache_remove(vdev_t *vd)
965 {
966 mutex_enter(&spa_l2cache_lock);
967 ASSERT(vd->vdev_isl2cache);
968 spa_aux_remove(vd, &spa_l2cache_avl);
969 vd->vdev_isl2cache = B_FALSE;
970 mutex_exit(&spa_l2cache_lock);
971 }
972
973 boolean_t
974 spa_l2cache_exists(uint64_t guid, uint64_t *pool)
975 {
976 boolean_t found;
977
978 mutex_enter(&spa_l2cache_lock);
979 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
980 mutex_exit(&spa_l2cache_lock);
981
982 return (found);
983 }
984
985 void
986 spa_l2cache_activate(vdev_t *vd)
987 {
988 mutex_enter(&spa_l2cache_lock);
989 ASSERT(vd->vdev_isl2cache);
990 spa_aux_activate(vd, &spa_l2cache_avl);
991 mutex_exit(&spa_l2cache_lock);
992 }
993
994 /*
995 * ==========================================================================
996 * SPA vdev locking
997 * ==========================================================================
998 */
999
1000 /*
1001 * Lock the given spa_t for the purpose of adding or removing a vdev.
1002 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
1003 * It returns the next transaction group for the spa_t.
1004 */
1005 uint64_t
1006 spa_vdev_enter(spa_t *spa)
1007 {
1008 mutex_enter(&spa->spa_vdev_top_lock);
1009 mutex_enter(&spa_namespace_lock);
1010 return (spa_vdev_config_enter(spa));
1011 }
1012
1013 /*
1014 * Internal implementation for spa_vdev_enter(). Used when a vdev
1015 * operation requires multiple syncs (i.e. removing a device) while
1016 * keeping the spa_namespace_lock held.
1017 */
1018 uint64_t
1019 spa_vdev_config_enter(spa_t *spa)
1020 {
1021 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1022
1023 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1024
1025 return (spa_last_synced_txg(spa) + 1);
1026 }
1027
1028 /*
1029 * Used in combination with spa_vdev_config_enter() to allow the syncing
1030 * of multiple transactions without releasing the spa_namespace_lock.
1031 */
1032 void
1033 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
1034 {
1035 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1036
1037 int config_changed = B_FALSE;
1038
1039 ASSERT(txg > spa_last_synced_txg(spa));
1040
1041 spa->spa_pending_vdev = NULL;
1042
1043 /*
1044 * Reassess the DTLs.
1045 */
1046 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
1047
1048 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
1049 config_changed = B_TRUE;
1050 spa->spa_config_generation++;
1051 }
1052
1053 /*
1054 * Verify the metaslab classes.
1055 */
1056 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
1057 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
1058
1059 spa_config_exit(spa, SCL_ALL, spa);
1060
1061 /*
1062 * Panic the system if the specified tag requires it. This
1063 * is useful for ensuring that configurations are updated
1064 * transactionally.
1065 */
1066 if (zio_injection_enabled)
1067 zio_handle_panic_injection(spa, tag, 0);
1068
1069 /*
1070 * Note: this txg_wait_synced() is important because it ensures
1071 * that there won't be more than one config change per txg.
1072 * This allows us to use the txg as the generation number.
1073 */
1074 if (error == 0)
1075 txg_wait_synced(spa->spa_dsl_pool, txg);
1076
1077 if (vd != NULL) {
1078 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL);
1079 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1080 vdev_free(vd);
1081 spa_config_exit(spa, SCL_ALL, spa);
1082 }
1083
1084 /*
1085 * If the config changed, update the config cache.
1086 */
1087 if (config_changed)
1088 spa_config_sync(spa, B_FALSE, B_TRUE);
1089 }
1090
1091 /*
1092 * Unlock the spa_t after adding or removing a vdev. Besides undoing the
1093 * locking of spa_vdev_enter(), we also want make sure the transactions have
1094 * synced to disk, and then update the global configuration cache with the new
1095 * information.
1096 */
1097 int
1098 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
1099 {
1100 spa_vdev_config_exit(spa, vd, txg, error, FTAG);
1101 mutex_exit(&spa_namespace_lock);
1102 mutex_exit(&spa->spa_vdev_top_lock);
1103
1104 return (error);
1105 }
1106
1107 /*
1108 * Lock the given spa_t for the purpose of changing vdev state.
1109 */
1110 void
1111 spa_vdev_state_enter(spa_t *spa, int oplocks)
1112 {
1113 int locks = SCL_STATE_ALL | oplocks;
1114
1115 /*
1116 * Root pools may need to read of the underlying devfs filesystem
1117 * when opening up a vdev. Unfortunately if we're holding the
1118 * SCL_ZIO lock it will result in a deadlock when we try to issue
1119 * the read from the root filesystem. Instead we "prefetch"
1120 * the associated vnodes that we need prior to opening the
1121 * underlying devices and cache them so that we can prevent
1122 * any I/O when we are doing the actual open.
1123 */
1124 if (spa_is_root(spa)) {
1125 int low = locks & ~(SCL_ZIO - 1);
1126 int high = locks & ~low;
1127
1128 spa_config_enter(spa, high, spa, RW_WRITER);
1129 vdev_hold(spa->spa_root_vdev);
1130 spa_config_enter(spa, low, spa, RW_WRITER);
1131 } else {
1132 spa_config_enter(spa, locks, spa, RW_WRITER);
1133 }
1134 spa->spa_vdev_locks = locks;
1135 }
1136
1137 int
1138 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
1139 {
1140 boolean_t config_changed = B_FALSE;
1141
1142 if (vd != NULL || error == 0)
1143 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
1144 0, 0, B_FALSE);
1145
1146 if (vd != NULL) {
1147 vdev_state_dirty(vd->vdev_top);
1148 config_changed = B_TRUE;
1149 spa->spa_config_generation++;
1150 }
1151
1152 if (spa_is_root(spa))
1153 vdev_rele(spa->spa_root_vdev);
1154
1155 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1156 spa_config_exit(spa, spa->spa_vdev_locks, spa);
1157
1158 /*
1159 * If anything changed, wait for it to sync. This ensures that,
1160 * from the system administrator's perspective, zpool(1M) commands
1161 * are synchronous. This is important for things like zpool offline:
1162 * when the command completes, you expect no further I/O from ZFS.
1163 */
1164 if (vd != NULL)
1165 txg_wait_synced(spa->spa_dsl_pool, 0);
1166
1167 /*
1168 * If the config changed, update the config cache.
1169 */
1170 if (config_changed) {
1171 mutex_enter(&spa_namespace_lock);
1172 spa_config_sync(spa, B_FALSE, B_TRUE);
1173 mutex_exit(&spa_namespace_lock);
1174 }
1175
1176 return (error);
1177 }
1178
1179 /*
1180 * ==========================================================================
1181 * Miscellaneous functions
1182 * ==========================================================================
1183 */
1184
1185 void
1186 spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx)
1187 {
1188 if (!nvlist_exists(spa->spa_label_features, feature)) {
1189 fnvlist_add_boolean(spa->spa_label_features, feature);
1190 /*
1191 * When we are creating the pool (tx_txg==TXG_INITIAL), we can't
1192 * dirty the vdev config because lock SCL_CONFIG is not held.
1193 * Thankfully, in this case we don't need to dirty the config
1194 * because it will be written out anyway when we finish
1195 * creating the pool.
1196 */
1197 if (tx->tx_txg != TXG_INITIAL)
1198 vdev_config_dirty(spa->spa_root_vdev);
1199 }
1200 }
1201
1202 void
1203 spa_deactivate_mos_feature(spa_t *spa, const char *feature)
1204 {
1205 if (nvlist_remove_all(spa->spa_label_features, feature) == 0)
1206 vdev_config_dirty(spa->spa_root_vdev);
1207 }
1208
1209 /*
1210 * Rename a spa_t.
1211 */
1212 int
1213 spa_rename(const char *name, const char *newname)
1214 {
1215 spa_t *spa;
1216 int err;
1217
1218 /*
1219 * Lookup the spa_t and grab the config lock for writing. We need to
1220 * actually open the pool so that we can sync out the necessary labels.
1221 * It's OK to call spa_open() with the namespace lock held because we
1222 * allow recursive calls for other reasons.
1223 */
1224 mutex_enter(&spa_namespace_lock);
1225 if ((err = spa_open(name, &spa, FTAG)) != 0) {
1226 mutex_exit(&spa_namespace_lock);
1227 return (err);
1228 }
1229
1230 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1231
1232 avl_remove(&spa_namespace_avl, spa);
1233 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1234 avl_add(&spa_namespace_avl, spa);
1235
1236 /*
1237 * Sync all labels to disk with the new names by marking the root vdev
1238 * dirty and waiting for it to sync. It will pick up the new pool name
1239 * during the sync.
1240 */
1241 vdev_config_dirty(spa->spa_root_vdev);
1242
1243 spa_config_exit(spa, SCL_ALL, FTAG);
1244
1245 txg_wait_synced(spa->spa_dsl_pool, 0);
1246
1247 /*
1248 * Sync the updated config cache.
1249 */
1250 spa_config_sync(spa, B_FALSE, B_TRUE);
1251
1252 spa_close(spa, FTAG);
1253
1254 mutex_exit(&spa_namespace_lock);
1255
1256 return (0);
1257 }
1258
1259 /*
1260 * Return the spa_t associated with given pool_guid, if it exists. If
1261 * device_guid is non-zero, determine whether the pool exists *and* contains
1262 * a device with the specified device_guid.
1263 */
1264 spa_t *
1265 spa_by_guid(uint64_t pool_guid, uint64_t device_guid)
1266 {
1267 spa_t *spa;
1268 avl_tree_t *t = &spa_namespace_avl;
1269
1270 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1271
1272 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1273 if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1274 continue;
1275 if (spa->spa_root_vdev == NULL)
1276 continue;
1277 if (spa_guid(spa) == pool_guid) {
1278 if (device_guid == 0)
1279 break;
1280
1281 if (vdev_lookup_by_guid(spa->spa_root_vdev,
1282 device_guid) != NULL)
1283 break;
1284
1285 /*
1286 * Check any devices we may be in the process of adding.
1287 */
1288 if (spa->spa_pending_vdev) {
1289 if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1290 device_guid) != NULL)
1291 break;
1292 }
1293 }
1294 }
1295
1296 return (spa);
1297 }
1298
1299 /*
1300 * Determine whether a pool with the given pool_guid exists.
1301 */
1302 boolean_t
1303 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1304 {
1305 return (spa_by_guid(pool_guid, device_guid) != NULL);
1306 }
1307
1308 char *
1309 spa_strdup(const char *s)
1310 {
1311 size_t len;
1312 char *new;
1313
1314 len = strlen(s);
1315 new = kmem_alloc(len + 1, KM_SLEEP);
1316 bcopy(s, new, len);
1317 new[len] = '\0';
1318
1319 return (new);
1320 }
1321
1322 void
1323 spa_strfree(char *s)
1324 {
1325 kmem_free(s, strlen(s) + 1);
1326 }
1327
1328 uint64_t
1329 spa_get_random(uint64_t range)
1330 {
1331 uint64_t r;
1332
1333 ASSERT(range != 0);
1334
1335 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1336
1337 return (r % range);
1338 }
1339
1340 uint64_t
1341 spa_generate_guid(spa_t *spa)
1342 {
1343 uint64_t guid = spa_get_random(-1ULL);
1344
1345 if (spa != NULL) {
1346 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1347 guid = spa_get_random(-1ULL);
1348 } else {
1349 while (guid == 0 || spa_guid_exists(guid, 0))
1350 guid = spa_get_random(-1ULL);
1351 }
1352
1353 return (guid);
1354 }
1355
1356 void
1357 snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp)
1358 {
1359 char type[256];
1360 char *checksum = NULL;
1361 char *compress = NULL;
1362
1363 if (bp != NULL) {
1364 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) {
1365 dmu_object_byteswap_t bswap =
1366 DMU_OT_BYTESWAP(BP_GET_TYPE(bp));
1367 (void) snprintf(type, sizeof (type), "bswap %s %s",
1368 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ?
1369 "metadata" : "data",
1370 dmu_ot_byteswap[bswap].ob_name);
1371 } else {
1372 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name,
1373 sizeof (type));
1374 }
1375 if (!BP_IS_EMBEDDED(bp)) {
1376 checksum =
1377 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name;
1378 }
1379 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name;
1380 }
1381
1382 SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum,
1383 compress);
1384 }
1385
1386 void
1387 spa_freeze(spa_t *spa)
1388 {
1389 uint64_t freeze_txg = 0;
1390
1391 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1392 if (spa->spa_freeze_txg == UINT64_MAX) {
1393 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1394 spa->spa_freeze_txg = freeze_txg;
1395 }
1396 spa_config_exit(spa, SCL_ALL, FTAG);
1397 if (freeze_txg != 0)
1398 txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1399 }
1400
1401 void
1402 zfs_panic_recover(const char *fmt, ...)
1403 {
1404 va_list adx;
1405
1406 va_start(adx, fmt);
1407 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1408 va_end(adx);
1409 }
1410
1411 /*
1412 * This is a stripped-down version of strtoull, suitable only for converting
1413 * lowercase hexadecimal numbers that don't overflow.
1414 */
1415 uint64_t
1416 strtonum(const char *str, char **nptr)
1417 {
1418 uint64_t val = 0;
1419 char c;
1420 int digit;
1421
1422 while ((c = *str) != '\0') {
1423 if (c >= '0' && c <= '9')
1424 digit = c - '0';
1425 else if (c >= 'a' && c <= 'f')
1426 digit = 10 + c - 'a';
1427 else
1428 break;
1429
1430 val *= 16;
1431 val += digit;
1432
1433 str++;
1434 }
1435
1436 if (nptr)
1437 *nptr = (char *)str;
1438
1439 return (val);
1440 }
1441
1442 /*
1443 * ==========================================================================
1444 * Accessor functions
1445 * ==========================================================================
1446 */
1447
1448 boolean_t
1449 spa_shutting_down(spa_t *spa)
1450 {
1451 return (spa->spa_async_suspended);
1452 }
1453
1454 dsl_pool_t *
1455 spa_get_dsl(spa_t *spa)
1456 {
1457 return (spa->spa_dsl_pool);
1458 }
1459
1460 boolean_t
1461 spa_is_initializing(spa_t *spa)
1462 {
1463 return (spa->spa_is_initializing);
1464 }
1465
1466 blkptr_t *
1467 spa_get_rootblkptr(spa_t *spa)
1468 {
1469 return (&spa->spa_ubsync.ub_rootbp);
1470 }
1471
1472 void
1473 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1474 {
1475 spa->spa_uberblock.ub_rootbp = *bp;
1476 }
1477
1478 void
1479 spa_altroot(spa_t *spa, char *buf, size_t buflen)
1480 {
1481 if (spa->spa_root == NULL)
1482 buf[0] = '\0';
1483 else
1484 (void) strncpy(buf, spa->spa_root, buflen);
1485 }
1486
1487 int
1488 spa_sync_pass(spa_t *spa)
1489 {
1490 return (spa->spa_sync_pass);
1491 }
1492
1493 char *
1494 spa_name(spa_t *spa)
1495 {
1496 return (spa->spa_name);
1497 }
1498
1499 uint64_t
1500 spa_guid(spa_t *spa)
1501 {
1502 dsl_pool_t *dp = spa_get_dsl(spa);
1503 uint64_t guid;
1504
1505 /*
1506 * If we fail to parse the config during spa_load(), we can go through
1507 * the error path (which posts an ereport) and end up here with no root
1508 * vdev. We stash the original pool guid in 'spa_config_guid' to handle
1509 * this case.
1510 */
1511 if (spa->spa_root_vdev == NULL)
1512 return (spa->spa_config_guid);
1513
1514 guid = spa->spa_last_synced_guid != 0 ?
1515 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid;
1516
1517 /*
1518 * Return the most recently synced out guid unless we're
1519 * in syncing context.
1520 */
1521 if (dp && dsl_pool_sync_context(dp))
1522 return (spa->spa_root_vdev->vdev_guid);
1523 else
1524 return (guid);
1525 }
1526
1527 uint64_t
1528 spa_load_guid(spa_t *spa)
1529 {
1530 /*
1531 * This is a GUID that exists solely as a reference for the
1532 * purposes of the arc. It is generated at load time, and
1533 * is never written to persistent storage.
1534 */
1535 return (spa->spa_load_guid);
1536 }
1537
1538 uint64_t
1539 spa_last_synced_txg(spa_t *spa)
1540 {
1541 return (spa->spa_ubsync.ub_txg);
1542 }
1543
1544 uint64_t
1545 spa_first_txg(spa_t *spa)
1546 {
1547 return (spa->spa_first_txg);
1548 }
1549
1550 uint64_t
1551 spa_syncing_txg(spa_t *spa)
1552 {
1553 return (spa->spa_syncing_txg);
1554 }
1555
1556 pool_state_t
1557 spa_state(spa_t *spa)
1558 {
1559 return (spa->spa_state);
1560 }
1561
1562 spa_load_state_t
1563 spa_load_state(spa_t *spa)
1564 {
1565 return (spa->spa_load_state);
1566 }
1567
1568 uint64_t
1569 spa_freeze_txg(spa_t *spa)
1570 {
1571 return (spa->spa_freeze_txg);
1572 }
1573
1574 /* ARGSUSED */
1575 uint64_t
1576 spa_get_asize(spa_t *spa, uint64_t lsize)
1577 {
1578 return (lsize * spa_asize_inflation);
1579 }
1580
1581 uint64_t
1582 spa_get_dspace(spa_t *spa)
1583 {
1584 return (spa->spa_dspace);
1585 }
1586
1587 void
1588 spa_update_dspace(spa_t *spa)
1589 {
1590 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1591 ddt_get_dedup_dspace(spa);
1592 }
1593
1594 /*
1595 * Return the failure mode that has been set to this pool. The default
1596 * behavior will be to block all I/Os when a complete failure occurs.
1597 */
1598 uint8_t
1599 spa_get_failmode(spa_t *spa)
1600 {
1601 return (spa->spa_failmode);
1602 }
1603
1604 boolean_t
1605 spa_suspended(spa_t *spa)
1606 {
1607 return (spa->spa_suspended);
1608 }
1609
1610 uint64_t
1611 spa_version(spa_t *spa)
1612 {
1613 return (spa->spa_ubsync.ub_version);
1614 }
1615
1616 boolean_t
1617 spa_deflate(spa_t *spa)
1618 {
1619 return (spa->spa_deflate);
1620 }
1621
1622 metaslab_class_t *
1623 spa_normal_class(spa_t *spa)
1624 {
1625 return (spa->spa_normal_class);
1626 }
1627
1628 metaslab_class_t *
1629 spa_log_class(spa_t *spa)
1630 {
1631 return (spa->spa_log_class);
1632 }
1633
1634 int
1635 spa_max_replication(spa_t *spa)
1636 {
1637 /*
1638 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1639 * handle BPs with more than one DVA allocated. Set our max
1640 * replication level accordingly.
1641 */
1642 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1643 return (1);
1644 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1645 }
1646
1647 int
1648 spa_prev_software_version(spa_t *spa)
1649 {
1650 return (spa->spa_prev_software_version);
1651 }
1652
1653 uint64_t
1654 spa_deadman_synctime(spa_t *spa)
1655 {
1656 return (spa->spa_deadman_synctime);
1657 }
1658
1659 uint64_t
1660 dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1661 {
1662 uint64_t asize = DVA_GET_ASIZE(dva);
1663 uint64_t dsize = asize;
1664
1665 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1666
1667 if (asize != 0 && spa->spa_deflate) {
1668 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1669 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1670 }
1671
1672 return (dsize);
1673 }
1674
1675 uint64_t
1676 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1677 {
1678 uint64_t dsize = 0;
1679
1680 for (int d = 0; d < BP_GET_NDVAS(bp); d++)
1681 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1682
1683 return (dsize);
1684 }
1685
1686 uint64_t
1687 bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1688 {
1689 uint64_t dsize = 0;
1690
1691 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1692
1693 for (int d = 0; d < BP_GET_NDVAS(bp); d++)
1694 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1695
1696 spa_config_exit(spa, SCL_VDEV, FTAG);
1697
1698 return (dsize);
1699 }
1700
1701 /*
1702 * ==========================================================================
1703 * Initialization and Termination
1704 * ==========================================================================
1705 */
1706
1707 static int
1708 spa_name_compare(const void *a1, const void *a2)
1709 {
1710 const spa_t *s1 = a1;
1711 const spa_t *s2 = a2;
1712 int s;
1713
1714 s = strcmp(s1->spa_name, s2->spa_name);
1715 if (s > 0)
1716 return (1);
1717 if (s < 0)
1718 return (-1);
1719 return (0);
1720 }
1721
1722 int
1723 spa_busy(void)
1724 {
1725 return (spa_active_count);
1726 }
1727
1728 void
1729 spa_boot_init()
1730 {
1731 spa_config_load();
1732 }
1733
1734 void
1735 spa_init(int mode)
1736 {
1737 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1738 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1739 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1740 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1741
1742 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1743 offsetof(spa_t, spa_avl));
1744
1745 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1746 offsetof(spa_aux_t, aux_avl));
1747
1748 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1749 offsetof(spa_aux_t, aux_avl));
1750
1751 spa_mode_global = mode;
1752
1753 #ifdef _KERNEL
1754 spa_arch_init();
1755 #else
1756 if (spa_mode_global != FREAD && dprintf_find_string("watch")) {
1757 arc_procfd = open("/proc/self/ctl", O_WRONLY);
1758 if (arc_procfd == -1) {
1759 perror("could not enable watchpoints: "
1760 "opening /proc/self/ctl failed: ");
1761 } else {
1762 arc_watch = B_TRUE;
1763 }
1764 }
1765 #endif
1766
1767 refcount_init();
1768 unique_init();
1769 range_tree_init();
1770 zio_init();
1771 dmu_init();
1772 zil_init();
1773 vdev_cache_stat_init();
1774 zfs_prop_init();
1775 zpool_prop_init();
1776 zpool_feature_init();
1777 spa_config_load();
1778 l2arc_start();
1779 }
1780
1781 void
1782 spa_fini(void)
1783 {
1784 l2arc_stop();
1785
1786 spa_evict_all();
1787
1788 vdev_cache_stat_fini();
1789 zil_fini();
1790 dmu_fini();
1791 zio_fini();
1792 range_tree_fini();
1793 unique_fini();
1794 refcount_fini();
1795
1796 avl_destroy(&spa_namespace_avl);
1797 avl_destroy(&spa_spare_avl);
1798 avl_destroy(&spa_l2cache_avl);
1799
1800 cv_destroy(&spa_namespace_cv);
1801 mutex_destroy(&spa_namespace_lock);
1802 mutex_destroy(&spa_spare_lock);
1803 mutex_destroy(&spa_l2cache_lock);
1804 }
1805
1806 /*
1807 * Return whether this pool has slogs. No locking needed.
1808 * It's not a problem if the wrong answer is returned as it's only for
1809 * performance and not correctness
1810 */
1811 boolean_t
1812 spa_has_slogs(spa_t *spa)
1813 {
1814 return (spa->spa_log_class->mc_rotor != NULL);
1815 }
1816
1817 spa_log_state_t
1818 spa_get_log_state(spa_t *spa)
1819 {
1820 return (spa->spa_log_state);
1821 }
1822
1823 void
1824 spa_set_log_state(spa_t *spa, spa_log_state_t state)
1825 {
1826 spa->spa_log_state = state;
1827 }
1828
1829 boolean_t
1830 spa_is_root(spa_t *spa)
1831 {
1832 return (spa->spa_is_root);
1833 }
1834
1835 boolean_t
1836 spa_writeable(spa_t *spa)
1837 {
1838 return (!!(spa->spa_mode & FWRITE));
1839 }
1840
1841 int
1842 spa_mode(spa_t *spa)
1843 {
1844 return (spa->spa_mode);
1845 }
1846
1847 uint64_t
1848 spa_bootfs(spa_t *spa)
1849 {
1850 return (spa->spa_bootfs);
1851 }
1852
1853 uint64_t
1854 spa_delegation(spa_t *spa)
1855 {
1856 return (spa->spa_delegation);
1857 }
1858
1859 objset_t *
1860 spa_meta_objset(spa_t *spa)
1861 {
1862 return (spa->spa_meta_objset);
1863 }
1864
1865 enum zio_checksum
1866 spa_dedup_checksum(spa_t *spa)
1867 {
1868 return (spa->spa_dedup_checksum);
1869 }
1870
1871 /*
1872 * Reset pool scan stat per scan pass (or reboot).
1873 */
1874 void
1875 spa_scan_stat_init(spa_t *spa)
1876 {
1877 /* data not stored on disk */
1878 spa->spa_scan_pass_start = gethrestime_sec();
1879 spa->spa_scan_pass_exam = 0;
1880 vdev_scan_stat_init(spa->spa_root_vdev);
1881 }
1882
1883 /*
1884 * Get scan stats for zpool status reports
1885 */
1886 int
1887 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps)
1888 {
1889 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL;
1890
1891 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE)
1892 return (SET_ERROR(ENOENT));
1893 bzero(ps, sizeof (pool_scan_stat_t));
1894
1895 /* data stored on disk */
1896 ps->pss_func = scn->scn_phys.scn_func;
1897 ps->pss_start_time = scn->scn_phys.scn_start_time;
1898 ps->pss_end_time = scn->scn_phys.scn_end_time;
1899 ps->pss_to_examine = scn->scn_phys.scn_to_examine;
1900 ps->pss_examined = scn->scn_phys.scn_examined;
1901 ps->pss_to_process = scn->scn_phys.scn_to_process;
1902 ps->pss_processed = scn->scn_phys.scn_processed;
1903 ps->pss_errors = scn->scn_phys.scn_errors;
1904 ps->pss_state = scn->scn_phys.scn_state;
1905
1906 /* data not stored on disk */
1907 ps->pss_pass_start = spa->spa_scan_pass_start;
1908 ps->pss_pass_exam = spa->spa_scan_pass_exam;
1909
1910 return (0);
1911 }
1912
1913 boolean_t
1914 spa_debug_enabled(spa_t *spa)
1915 {
1916 return (spa->spa_debug);
1917 }