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) 2011, 2014 by Delphix. All rights reserved.
24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
26 */
27
28 #include <sys/zfs_context.h>
29 #include <sys/spa_impl.h>
30 #include <sys/spa_boot.h>
31 #include <sys/zio.h>
32 #include <sys/zio_checksum.h>
33 #include <sys/zio_compress.h>
34 #include <sys/dmu.h>
35 #include <sys/dmu_tx.h>
36 #include <sys/zap.h>
37 #include <sys/zil.h>
38 #include <sys/vdev_impl.h>
39 #include <sys/metaslab.h>
40 #include <sys/uberblock_impl.h>
41 #include <sys/txg.h>
42 #include <sys/avl.h>
43 #include <sys/unique.h>
44 #include <sys/dsl_pool.h>
45 #include <sys/dsl_dir.h>
46 #include <sys/dsl_prop.h>
47 #include <sys/dsl_scan.h>
48 #include <sys/fs/zfs.h>
49 #include <sys/metaslab_impl.h>
50 #include <sys/arc.h>
51 #include <sys/ddt.h>
52 #include "zfs_prop.h"
53 #include "zfeature_common.h"
54
55 /*
56 * SPA locking
57 *
58 * There are four basic locks for managing spa_t structures:
59 *
60 * spa_namespace_lock (global mutex)
61 *
62 * This lock must be acquired to do any of the following:
63 *
64 * - Lookup a spa_t by name
65 * - Add or remove a spa_t from the namespace
66 * - Increase spa_refcount from non-zero
67 * - Check if spa_refcount is zero
68 * - Rename a spa_t
69 * - add/remove/attach/detach devices
70 * - Held for the duration of create/destroy/import/export
71 *
72 * It does not need to handle recursion. A create or destroy may
73 * reference objects (files or zvols) in other pools, but by
74 * definition they must have an existing reference, and will never need
75 * to lookup a spa_t by name.
76 *
77 * spa_refcount (per-spa refcount_t protected by mutex)
78 *
79 * This reference count keep track of any active users of the spa_t. The
80 * spa_t cannot be destroyed or freed while this is non-zero. Internally,
81 * the refcount is never really 'zero' - opening a pool implicitly keeps
82 * some references in the DMU. Internally we check against spa_minref, but
83 * present the image of a zero/non-zero value to consumers.
84 *
85 * spa_config_lock[] (per-spa array of rwlocks)
86 *
87 * This protects the spa_t from config changes, and must be held in
88 * the following circumstances:
89 *
90 * - RW_READER to perform I/O to the spa
91 * - RW_WRITER to change the vdev config
92 *
93 * The locking order is fairly straightforward:
94 *
95 * spa_namespace_lock -> spa_refcount
96 *
97 * The namespace lock must be acquired to increase the refcount from 0
98 * or to check if it is zero.
99 *
100 * spa_refcount -> spa_config_lock[]
101 *
102 * There must be at least one valid reference on the spa_t to acquire
103 * the config lock.
104 *
105 * spa_namespace_lock -> spa_config_lock[]
106 *
107 * The namespace lock must always be taken before the config lock.
108 *
109 *
110 * The spa_namespace_lock can be acquired directly and is globally visible.
111 *
112 * The namespace is manipulated using the following functions, all of which
113 * require the spa_namespace_lock to be held.
114 *
115 * spa_lookup() Lookup a spa_t by name.
116 *
117 * spa_add() Create a new spa_t in the namespace.
118 *
119 * spa_remove() Remove a spa_t from the namespace. This also
120 * frees up any memory associated with the spa_t.
121 *
122 * spa_next() Returns the next spa_t in the system, or the
123 * first if NULL is passed.
124 *
125 * spa_evict_all() Shutdown and remove all spa_t structures in
126 * the system.
127 *
128 * spa_guid_exists() Determine whether a pool/device guid exists.
129 *
130 * The spa_refcount is manipulated using the following functions:
131 *
132 * spa_open_ref() Adds a reference to the given spa_t. Must be
133 * called with spa_namespace_lock held if the
134 * refcount is currently zero.
135 *
136 * spa_close() Remove a reference from the spa_t. This will
137 * not free the spa_t or remove it from the
138 * namespace. No locking is required.
139 *
140 * spa_refcount_zero() Returns true if the refcount is currently
141 * zero. Must be called with spa_namespace_lock
142 * held.
143 *
144 * The spa_config_lock[] is an array of rwlocks, ordered as follows:
145 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
146 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
147 *
148 * To read the configuration, it suffices to hold one of these locks as reader.
149 * To modify the configuration, you must hold all locks as writer. To modify
150 * vdev state without altering the vdev tree's topology (e.g. online/offline),
151 * you must hold SCL_STATE and SCL_ZIO as writer.
152 *
153 * We use these distinct config locks to avoid recursive lock entry.
154 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
155 * block allocations (SCL_ALLOC), which may require reading space maps
156 * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
157 *
158 * The spa config locks cannot be normal rwlocks because we need the
159 * ability to hand off ownership. For example, SCL_ZIO is acquired
160 * by the issuing thread and later released by an interrupt thread.
161 * They do, however, obey the usual write-wanted semantics to prevent
162 * writer (i.e. system administrator) starvation.
163 *
164 * The lock acquisition rules are as follows:
165 *
166 * SCL_CONFIG
167 * Protects changes to the vdev tree topology, such as vdev
168 * add/remove/attach/detach. Protects the dirty config list
169 * (spa_config_dirty_list) and the set of spares and l2arc devices.
170 *
171 * SCL_STATE
172 * Protects changes to pool state and vdev state, such as vdev
173 * online/offline/fault/degrade/clear. Protects the dirty state list
174 * (spa_state_dirty_list) and global pool state (spa_state).
175 *
176 * SCL_ALLOC
177 * Protects changes to metaslab groups and classes.
178 * Held as reader by metaslab_alloc() and metaslab_claim().
179 *
180 * SCL_ZIO
181 * Held by bp-level zios (those which have no io_vd upon entry)
182 * to prevent changes to the vdev tree. The bp-level zio implicitly
183 * protects all of its vdev child zios, which do not hold SCL_ZIO.
184 *
185 * SCL_FREE
186 * Protects changes to metaslab groups and classes.
187 * Held as reader by metaslab_free(). SCL_FREE is distinct from
188 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
189 * blocks in zio_done() while another i/o that holds either
190 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
191 *
192 * SCL_VDEV
193 * Held as reader to prevent changes to the vdev tree during trivial
194 * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the
195 * other locks, and lower than all of them, to ensure that it's safe
196 * to acquire regardless of caller context.
197 *
198 * In addition, the following rules apply:
199 *
200 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list.
201 * The lock ordering is SCL_CONFIG > spa_props_lock.
202 *
203 * (b) I/O operations on leaf vdevs. For any zio operation that takes
204 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
205 * or zio_write_phys() -- the caller must ensure that the config cannot
206 * cannot change in the interim, and that the vdev cannot be reopened.
207 * SCL_STATE as reader suffices for both.
208 *
209 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
210 *
211 * spa_vdev_enter() Acquire the namespace lock and the config lock
212 * for writing.
213 *
214 * spa_vdev_exit() Release the config lock, wait for all I/O
215 * to complete, sync the updated configs to the
216 * cache, and release the namespace lock.
217 *
218 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
219 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
220 * locking is, always, based on spa_namespace_lock and spa_config_lock[].
221 *
222 * spa_rename() is also implemented within this file since it requires
223 * manipulation of the namespace.
224 */
225
226 static avl_tree_t spa_namespace_avl;
227 kmutex_t spa_namespace_lock;
228 static kcondvar_t spa_namespace_cv;
229 static int spa_active_count;
230 int spa_max_replication_override = SPA_DVAS_PER_BP;
231
232 static kmutex_t spa_spare_lock;
233 static avl_tree_t spa_spare_avl;
234 static kmutex_t spa_l2cache_lock;
235 static avl_tree_t spa_l2cache_avl;
236
237 kmem_cache_t *spa_buffer_pool;
238 int spa_mode_global;
239
240 #ifdef ZFS_DEBUG
241 /* Everything except dprintf and spa is on by default in debug builds */
242 int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA);
243 #else
244 int zfs_flags = 0;
245 #endif
246
247 /*
248 * zfs_recover can be set to nonzero to attempt to recover from
249 * otherwise-fatal errors, typically caused by on-disk corruption. When
250 * set, calls to zfs_panic_recover() will turn into warning messages.
251 * This should only be used as a last resort, as it typically results
252 * in leaked space, or worse.
253 */
254 boolean_t zfs_recover = B_FALSE;
255
256 /*
257 * If destroy encounters an EIO while reading metadata (e.g. indirect
258 * blocks), space referenced by the missing metadata can not be freed.
259 * Normally this causes the background destroy to become "stalled", as
260 * it is unable to make forward progress. While in this stalled state,
261 * all remaining space to free from the error-encountering filesystem is
262 * "temporarily leaked". Set this flag to cause it to ignore the EIO,
263 * permanently leak the space from indirect blocks that can not be read,
264 * and continue to free everything else that it can.
265 *
266 * The default, "stalling" behavior is useful if the storage partially
267 * fails (i.e. some but not all i/os fail), and then later recovers. In
268 * this case, we will be able to continue pool operations while it is
269 * partially failed, and when it recovers, we can continue to free the
270 * space, with no leaks. However, note that this case is actually
271 * fairly rare.
272 *
273 * Typically pools either (a) fail completely (but perhaps temporarily,
274 * e.g. a top-level vdev going offline), or (b) have localized,
275 * permanent errors (e.g. disk returns the wrong data due to bit flip or
276 * firmware bug). In case (a), this setting does not matter because the
277 * pool will be suspended and the sync thread will not be able to make
278 * forward progress regardless. In case (b), because the error is
279 * permanent, the best we can do is leak the minimum amount of space,
280 * which is what setting this flag will do. Therefore, it is reasonable
281 * for this flag to normally be set, but we chose the more conservative
282 * approach of not setting it, so that there is no possibility of
283 * leaking space in the "partial temporary" failure case.
284 */
285 boolean_t zfs_free_leak_on_eio = B_FALSE;
286
287 /*
288 * Expiration time in milliseconds. This value has two meanings. First it is
289 * used to determine when the spa_deadman() logic should fire. By default the
290 * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds.
291 * Secondly, the value determines if an I/O is considered "hung". Any I/O that
292 * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting
293 * in a system panic.
294 */
295 uint64_t zfs_deadman_synctime_ms = 1000000ULL;
296
297 /*
298 * Check time in milliseconds. This defines the frequency at which we check
299 * for hung I/O.
300 */
301 uint64_t zfs_deadman_checktime_ms = 5000ULL;
302
303 /*
304 * Override the zfs deadman behavior via /etc/system. By default the
305 * deadman is enabled except on VMware and sparc deployments.
306 */
307 int zfs_deadman_enabled = -1;
308
309 /*
310 * The worst case is single-sector max-parity RAID-Z blocks, in which
311 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
312 * times the size; so just assume that. Add to this the fact that
313 * we can have up to 3 DVAs per bp, and one more factor of 2 because
314 * the block may be dittoed with up to 3 DVAs by ddt_sync(). All together,
315 * the worst case is:
316 * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24
317 */
318 int spa_asize_inflation = 24;
319
320 /*
321 * Normally, we don't allow the last 3.2% (1/(2^spa_slop_shift)) of space in
322 * the pool to be consumed. This ensures that we don't run the pool
323 * completely out of space, due to unaccounted changes (e.g. to the MOS).
324 * It also limits the worst-case time to allocate space. If we have
325 * less than this amount of free space, most ZPL operations (e.g. write,
326 * create) will return ENOSPC.
327 *
328 * Certain operations (e.g. file removal, most administrative actions) can
329 * use half the slop space. They will only return ENOSPC if less than half
330 * the slop space is free. Typically, once the pool has less than the slop
331 * space free, the user will use these operations to free up space in the pool.
332 * These are the operations that call dsl_pool_adjustedsize() with the netfree
333 * argument set to TRUE.
334 *
335 * A very restricted set of operations are always permitted, regardless of
336 * the amount of free space. These are the operations that call
337 * dsl_sync_task(ZFS_SPACE_CHECK_NONE), e.g. "zfs destroy". If these
338 * operations result in a net increase in the amount of space used,
339 * it is possible to run the pool completely out of space, causing it to
340 * be permanently read-only.
341 *
342 * See also the comments in zfs_space_check_t.
343 */
344 int spa_slop_shift = 5;
345
346 /*
347 * ==========================================================================
348 * SPA config locking
349 * ==========================================================================
350 */
351 static void
352 spa_config_lock_init(spa_t *spa)
353 {
354 for (int i = 0; i < SCL_LOCKS; i++) {
355 spa_config_lock_t *scl = &spa->spa_config_lock[i];
356 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
357 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
358 refcount_create_untracked(&scl->scl_count);
359 scl->scl_writer = NULL;
360 scl->scl_write_wanted = 0;
361 }
362 }
363
364 static void
365 spa_config_lock_destroy(spa_t *spa)
366 {
367 for (int i = 0; i < SCL_LOCKS; i++) {
368 spa_config_lock_t *scl = &spa->spa_config_lock[i];
369 mutex_destroy(&scl->scl_lock);
370 cv_destroy(&scl->scl_cv);
371 refcount_destroy(&scl->scl_count);
372 ASSERT(scl->scl_writer == NULL);
373 ASSERT(scl->scl_write_wanted == 0);
374 }
375 }
376
377 int
378 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
379 {
380 for (int i = 0; i < SCL_LOCKS; i++) {
381 spa_config_lock_t *scl = &spa->spa_config_lock[i];
382 if (!(locks & (1 << i)))
383 continue;
384 mutex_enter(&scl->scl_lock);
385 if (rw == RW_READER) {
386 if (scl->scl_writer || scl->scl_write_wanted) {
387 mutex_exit(&scl->scl_lock);
388 spa_config_exit(spa, locks ^ (1 << i), tag);
389 return (0);
390 }
391 } else {
392 ASSERT(scl->scl_writer != curthread);
393 if (!refcount_is_zero(&scl->scl_count)) {
394 mutex_exit(&scl->scl_lock);
395 spa_config_exit(spa, locks ^ (1 << i), tag);
396 return (0);
397 }
398 scl->scl_writer = curthread;
399 }
400 (void) refcount_add(&scl->scl_count, tag);
401 mutex_exit(&scl->scl_lock);
402 }
403 return (1);
404 }
405
406 void
407 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
408 {
409 int wlocks_held = 0;
410
411 ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY);
412
413 for (int i = 0; i < SCL_LOCKS; i++) {
414 spa_config_lock_t *scl = &spa->spa_config_lock[i];
415 if (scl->scl_writer == curthread)
416 wlocks_held |= (1 << i);
417 if (!(locks & (1 << i)))
418 continue;
419 mutex_enter(&scl->scl_lock);
420 if (rw == RW_READER) {
421 while (scl->scl_writer || scl->scl_write_wanted) {
422 cv_wait(&scl->scl_cv, &scl->scl_lock);
423 }
424 } else {
425 ASSERT(scl->scl_writer != curthread);
426 while (!refcount_is_zero(&scl->scl_count)) {
427 scl->scl_write_wanted++;
428 cv_wait(&scl->scl_cv, &scl->scl_lock);
429 scl->scl_write_wanted--;
430 }
431 scl->scl_writer = curthread;
432 }
433 (void) refcount_add(&scl->scl_count, tag);
434 mutex_exit(&scl->scl_lock);
435 }
436 ASSERT(wlocks_held <= locks);
437 }
438
439 void
440 spa_config_exit(spa_t *spa, int locks, void *tag)
441 {
442 for (int i = SCL_LOCKS - 1; i >= 0; i--) {
443 spa_config_lock_t *scl = &spa->spa_config_lock[i];
444 if (!(locks & (1 << i)))
445 continue;
446 mutex_enter(&scl->scl_lock);
447 ASSERT(!refcount_is_zero(&scl->scl_count));
448 if (refcount_remove(&scl->scl_count, tag) == 0) {
449 ASSERT(scl->scl_writer == NULL ||
450 scl->scl_writer == curthread);
451 scl->scl_writer = NULL; /* OK in either case */
452 cv_broadcast(&scl->scl_cv);
453 }
454 mutex_exit(&scl->scl_lock);
455 }
456 }
457
458 int
459 spa_config_held(spa_t *spa, int locks, krw_t rw)
460 {
461 int locks_held = 0;
462
463 for (int i = 0; i < SCL_LOCKS; i++) {
464 spa_config_lock_t *scl = &spa->spa_config_lock[i];
465 if (!(locks & (1 << i)))
466 continue;
467 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
468 (rw == RW_WRITER && scl->scl_writer == curthread))
469 locks_held |= 1 << i;
470 }
471
472 return (locks_held);
473 }
474
475 /*
476 * ==========================================================================
477 * SPA namespace functions
478 * ==========================================================================
479 */
480
481 /*
482 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held.
483 * Returns NULL if no matching spa_t is found.
484 */
485 spa_t *
486 spa_lookup(const char *name)
487 {
488 static spa_t search; /* spa_t is large; don't allocate on stack */
489 spa_t *spa;
490 avl_index_t where;
491 char *cp;
492
493 ASSERT(MUTEX_HELD(&spa_namespace_lock));
494
495 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
496
497 /*
498 * If it's a full dataset name, figure out the pool name and
499 * just use that.
500 */
501 cp = strpbrk(search.spa_name, "/@#");
502 if (cp != NULL)
503 *cp = '\0';
504
505 spa = avl_find(&spa_namespace_avl, &search, &where);
506
507 return (spa);
508 }
509
510 /*
511 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms.
512 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues
513 * looking for potentially hung I/Os.
514 */
515 void
516 spa_deadman(void *arg)
517 {
518 spa_t *spa = arg;
519
520 /*
521 * Disable the deadman timer if the pool is suspended.
522 */
523 if (spa_suspended(spa)) {
524 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
525 return;
526 }
527
528 zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu",
529 (gethrtime() - spa->spa_sync_starttime) / NANOSEC,
530 ++spa->spa_deadman_calls);
531 if (zfs_deadman_enabled)
532 vdev_deadman(spa->spa_root_vdev);
533 }
534
535 /*
536 * Create an uninitialized spa_t with the given name. Requires
537 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already
538 * exist by calling spa_lookup() first.
539 */
540 spa_t *
541 spa_add(const char *name, nvlist_t *config, const char *altroot)
542 {
543 spa_t *spa;
544 spa_config_dirent_t *dp;
545 cyc_handler_t hdlr;
546 cyc_time_t when;
547
548 ASSERT(MUTEX_HELD(&spa_namespace_lock));
549
550 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
551
552 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
553 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
554 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
555 mutex_init(&spa->spa_evicting_os_lock, NULL, MUTEX_DEFAULT, NULL);
556 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
557 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL);
558 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
559 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
560 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
561 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL);
562 mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL);
563
564 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
565 cv_init(&spa->spa_evicting_os_cv, NULL, CV_DEFAULT, NULL);
566 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL);
567 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
568 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
569
570 for (int t = 0; t < TXG_SIZE; t++)
571 bplist_create(&spa->spa_free_bplist[t]);
572
573 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
574 spa->spa_state = POOL_STATE_UNINITIALIZED;
575 spa->spa_freeze_txg = UINT64_MAX;
576 spa->spa_final_txg = UINT64_MAX;
577 spa->spa_load_max_txg = UINT64_MAX;
578 spa->spa_proc = &p0;
579 spa->spa_proc_state = SPA_PROC_NONE;
580
581 hdlr.cyh_func = spa_deadman;
582 hdlr.cyh_arg = spa;
583 hdlr.cyh_level = CY_LOW_LEVEL;
584
585 spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms);
586
587 /*
588 * This determines how often we need to check for hung I/Os after
589 * the cyclic has already fired. Since checking for hung I/Os is
590 * an expensive operation we don't want to check too frequently.
591 * Instead wait for 5 seconds before checking again.
592 */
593 when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms);
594 when.cyt_when = CY_INFINITY;
595 mutex_enter(&cpu_lock);
596 spa->spa_deadman_cycid = cyclic_add(&hdlr, &when);
597 mutex_exit(&cpu_lock);
598
599 refcount_create(&spa->spa_refcount);
600 spa_config_lock_init(spa);
601
602 avl_add(&spa_namespace_avl, spa);
603
604 /*
605 * Set the alternate root, if there is one.
606 */
607 if (altroot) {
608 spa->spa_root = spa_strdup(altroot);
609 spa_active_count++;
610 }
611
612 /*
613 * Every pool starts with the default cachefile
614 */
615 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
616 offsetof(spa_config_dirent_t, scd_link));
617
618 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
619 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
620 list_insert_head(&spa->spa_config_list, dp);
621
622 VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME,
623 KM_SLEEP) == 0);
624
625 if (config != NULL) {
626 nvlist_t *features;
627
628 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
629 &features) == 0) {
630 VERIFY(nvlist_dup(features, &spa->spa_label_features,
631 0) == 0);
632 }
633
634 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
635 }
636
637 if (spa->spa_label_features == NULL) {
638 VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME,
639 KM_SLEEP) == 0);
640 }
641
642 spa->spa_iokstat = kstat_create("zfs", 0, name,
643 "disk", KSTAT_TYPE_IO, 1, 0);
644 if (spa->spa_iokstat) {
645 spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock;
646 kstat_install(spa->spa_iokstat);
647 }
648
649 spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0);
650
651 /*
652 * As a pool is being created, treat all features as disabled by
653 * setting SPA_FEATURE_DISABLED for all entries in the feature
654 * refcount cache.
655 */
656 for (int i = 0; i < SPA_FEATURES; i++) {
657 spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED;
658 }
659
660 return (spa);
661 }
662
663 /*
664 * Removes a spa_t from the namespace, freeing up any memory used. Requires
665 * spa_namespace_lock. This is called only after the spa_t has been closed and
666 * deactivated.
667 */
668 void
669 spa_remove(spa_t *spa)
670 {
671 spa_config_dirent_t *dp;
672
673 ASSERT(MUTEX_HELD(&spa_namespace_lock));
674 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
675 ASSERT3U(refcount_count(&spa->spa_refcount), ==, 0);
676
677 nvlist_free(spa->spa_config_splitting);
678
679 avl_remove(&spa_namespace_avl, spa);
680 cv_broadcast(&spa_namespace_cv);
681
682 if (spa->spa_root) {
683 spa_strfree(spa->spa_root);
684 spa_active_count--;
685 }
686
687 while ((dp = list_head(&spa->spa_config_list)) != NULL) {
688 list_remove(&spa->spa_config_list, dp);
689 if (dp->scd_path != NULL)
690 spa_strfree(dp->scd_path);
691 kmem_free(dp, sizeof (spa_config_dirent_t));
692 }
693
694 list_destroy(&spa->spa_config_list);
695
696 nvlist_free(spa->spa_label_features);
697 nvlist_free(spa->spa_load_info);
698 spa_config_set(spa, NULL);
699
700 mutex_enter(&cpu_lock);
701 if (spa->spa_deadman_cycid != CYCLIC_NONE)
702 cyclic_remove(spa->spa_deadman_cycid);
703 mutex_exit(&cpu_lock);
704 spa->spa_deadman_cycid = CYCLIC_NONE;
705
706 refcount_destroy(&spa->spa_refcount);
707
708 spa_config_lock_destroy(spa);
709
710 kstat_delete(spa->spa_iokstat);
711 spa->spa_iokstat = NULL;
712
713 for (int t = 0; t < TXG_SIZE; t++)
714 bplist_destroy(&spa->spa_free_bplist[t]);
715
716 cv_destroy(&spa->spa_async_cv);
717 cv_destroy(&spa->spa_evicting_os_cv);
718 cv_destroy(&spa->spa_proc_cv);
719 cv_destroy(&spa->spa_scrub_io_cv);
720 cv_destroy(&spa->spa_suspend_cv);
721
722 mutex_destroy(&spa->spa_async_lock);
723 mutex_destroy(&spa->spa_errlist_lock);
724 mutex_destroy(&spa->spa_errlog_lock);
725 mutex_destroy(&spa->spa_evicting_os_lock);
726 mutex_destroy(&spa->spa_history_lock);
727 mutex_destroy(&spa->spa_proc_lock);
728 mutex_destroy(&spa->spa_props_lock);
729 mutex_destroy(&spa->spa_scrub_lock);
730 mutex_destroy(&spa->spa_suspend_lock);
731 mutex_destroy(&spa->spa_vdev_top_lock);
732 mutex_destroy(&spa->spa_iokstat_lock);
733
734 kmem_free(spa, sizeof (spa_t));
735 }
736
737 /*
738 * Given a pool, return the next pool in the namespace, or NULL if there is
739 * none. If 'prev' is NULL, return the first pool.
740 */
741 spa_t *
742 spa_next(spa_t *prev)
743 {
744 ASSERT(MUTEX_HELD(&spa_namespace_lock));
745
746 if (prev)
747 return (AVL_NEXT(&spa_namespace_avl, prev));
748 else
749 return (avl_first(&spa_namespace_avl));
750 }
751
752 /*
753 * ==========================================================================
754 * SPA refcount functions
755 * ==========================================================================
756 */
757
758 /*
759 * Add a reference to the given spa_t. Must have at least one reference, or
760 * have the namespace lock held.
761 */
762 void
763 spa_open_ref(spa_t *spa, void *tag)
764 {
765 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
766 MUTEX_HELD(&spa_namespace_lock));
767 (void) refcount_add(&spa->spa_refcount, tag);
768 }
769
770 /*
771 * Remove a reference to the given spa_t. Must have at least one reference, or
772 * have the namespace lock held.
773 */
774 void
775 spa_close(spa_t *spa, void *tag)
776 {
777 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
778 MUTEX_HELD(&spa_namespace_lock));
779 (void) refcount_remove(&spa->spa_refcount, tag);
780 }
781
782 /*
783 * Remove a reference to the given spa_t held by a dsl dir that is
784 * being asynchronously released. Async releases occur from a taskq
785 * performing eviction of dsl datasets and dirs. The namespace lock
786 * isn't held and the hold by the object being evicted may contribute to
787 * spa_minref (e.g. dataset or directory released during pool export),
788 * so the asserts in spa_close() do not apply.
789 */
790 void
791 spa_async_close(spa_t *spa, void *tag)
792 {
793 (void) refcount_remove(&spa->spa_refcount, tag);
794 }
795
796 /*
797 * Check to see if the spa refcount is zero. Must be called with
798 * spa_namespace_lock held. We really compare against spa_minref, which is the
799 * number of references acquired when opening a pool
800 */
801 boolean_t
802 spa_refcount_zero(spa_t *spa)
803 {
804 ASSERT(MUTEX_HELD(&spa_namespace_lock));
805
806 return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
807 }
808
809 /*
810 * ==========================================================================
811 * SPA spare and l2cache tracking
812 * ==========================================================================
813 */
814
815 /*
816 * Hot spares and cache devices are tracked using the same code below,
817 * for 'auxiliary' devices.
818 */
819
820 typedef struct spa_aux {
821 uint64_t aux_guid;
822 uint64_t aux_pool;
823 avl_node_t aux_avl;
824 int aux_count;
825 } spa_aux_t;
826
827 static int
828 spa_aux_compare(const void *a, const void *b)
829 {
830 const spa_aux_t *sa = a;
831 const spa_aux_t *sb = b;
832
833 if (sa->aux_guid < sb->aux_guid)
834 return (-1);
835 else if (sa->aux_guid > sb->aux_guid)
836 return (1);
837 else
838 return (0);
839 }
840
841 void
842 spa_aux_add(vdev_t *vd, avl_tree_t *avl)
843 {
844 avl_index_t where;
845 spa_aux_t search;
846 spa_aux_t *aux;
847
848 search.aux_guid = vd->vdev_guid;
849 if ((aux = avl_find(avl, &search, &where)) != NULL) {
850 aux->aux_count++;
851 } else {
852 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
853 aux->aux_guid = vd->vdev_guid;
854 aux->aux_count = 1;
855 avl_insert(avl, aux, where);
856 }
857 }
858
859 void
860 spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
861 {
862 spa_aux_t search;
863 spa_aux_t *aux;
864 avl_index_t where;
865
866 search.aux_guid = vd->vdev_guid;
867 aux = avl_find(avl, &search, &where);
868
869 ASSERT(aux != NULL);
870
871 if (--aux->aux_count == 0) {
872 avl_remove(avl, aux);
873 kmem_free(aux, sizeof (spa_aux_t));
874 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
875 aux->aux_pool = 0ULL;
876 }
877 }
878
879 boolean_t
880 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
881 {
882 spa_aux_t search, *found;
883
884 search.aux_guid = guid;
885 found = avl_find(avl, &search, NULL);
886
887 if (pool) {
888 if (found)
889 *pool = found->aux_pool;
890 else
891 *pool = 0ULL;
892 }
893
894 if (refcnt) {
895 if (found)
896 *refcnt = found->aux_count;
897 else
898 *refcnt = 0;
899 }
900
901 return (found != NULL);
902 }
903
904 void
905 spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
906 {
907 spa_aux_t search, *found;
908 avl_index_t where;
909
910 search.aux_guid = vd->vdev_guid;
911 found = avl_find(avl, &search, &where);
912 ASSERT(found != NULL);
913 ASSERT(found->aux_pool == 0ULL);
914
915 found->aux_pool = spa_guid(vd->vdev_spa);
916 }
917
918 /*
919 * Spares are tracked globally due to the following constraints:
920 *
921 * - A spare may be part of multiple pools.
922 * - A spare may be added to a pool even if it's actively in use within
923 * another pool.
924 * - A spare in use in any pool can only be the source of a replacement if
925 * the target is a spare in the same pool.
926 *
927 * We keep track of all spares on the system through the use of a reference
928 * counted AVL tree. When a vdev is added as a spare, or used as a replacement
929 * spare, then we bump the reference count in the AVL tree. In addition, we set
930 * the 'vdev_isspare' member to indicate that the device is a spare (active or
931 * inactive). When a spare is made active (used to replace a device in the
932 * pool), we also keep track of which pool its been made a part of.
933 *
934 * The 'spa_spare_lock' protects the AVL tree. These functions are normally
935 * called under the spa_namespace lock as part of vdev reconfiguration. The
936 * separate spare lock exists for the status query path, which does not need to
937 * be completely consistent with respect to other vdev configuration changes.
938 */
939
940 static int
941 spa_spare_compare(const void *a, const void *b)
942 {
943 return (spa_aux_compare(a, b));
944 }
945
946 void
947 spa_spare_add(vdev_t *vd)
948 {
949 mutex_enter(&spa_spare_lock);
950 ASSERT(!vd->vdev_isspare);
951 spa_aux_add(vd, &spa_spare_avl);
952 vd->vdev_isspare = B_TRUE;
953 mutex_exit(&spa_spare_lock);
954 }
955
956 void
957 spa_spare_remove(vdev_t *vd)
958 {
959 mutex_enter(&spa_spare_lock);
960 ASSERT(vd->vdev_isspare);
961 spa_aux_remove(vd, &spa_spare_avl);
962 vd->vdev_isspare = B_FALSE;
963 mutex_exit(&spa_spare_lock);
964 }
965
966 boolean_t
967 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
968 {
969 boolean_t found;
970
971 mutex_enter(&spa_spare_lock);
972 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
973 mutex_exit(&spa_spare_lock);
974
975 return (found);
976 }
977
978 void
979 spa_spare_activate(vdev_t *vd)
980 {
981 mutex_enter(&spa_spare_lock);
982 ASSERT(vd->vdev_isspare);
983 spa_aux_activate(vd, &spa_spare_avl);
984 mutex_exit(&spa_spare_lock);
985 }
986
987 /*
988 * Level 2 ARC devices are tracked globally for the same reasons as spares.
989 * Cache devices currently only support one pool per cache device, and so
990 * for these devices the aux reference count is currently unused beyond 1.
991 */
992
993 static int
994 spa_l2cache_compare(const void *a, const void *b)
995 {
996 return (spa_aux_compare(a, b));
997 }
998
999 void
1000 spa_l2cache_add(vdev_t *vd)
1001 {
1002 mutex_enter(&spa_l2cache_lock);
1003 ASSERT(!vd->vdev_isl2cache);
1004 spa_aux_add(vd, &spa_l2cache_avl);
1005 vd->vdev_isl2cache = B_TRUE;
1006 mutex_exit(&spa_l2cache_lock);
1007 }
1008
1009 void
1010 spa_l2cache_remove(vdev_t *vd)
1011 {
1012 mutex_enter(&spa_l2cache_lock);
1013 ASSERT(vd->vdev_isl2cache);
1014 spa_aux_remove(vd, &spa_l2cache_avl);
1015 vd->vdev_isl2cache = B_FALSE;
1016 mutex_exit(&spa_l2cache_lock);
1017 }
1018
1019 boolean_t
1020 spa_l2cache_exists(uint64_t guid, uint64_t *pool)
1021 {
1022 boolean_t found;
1023
1024 mutex_enter(&spa_l2cache_lock);
1025 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
1026 mutex_exit(&spa_l2cache_lock);
1027
1028 return (found);
1029 }
1030
1031 void
1032 spa_l2cache_activate(vdev_t *vd)
1033 {
1034 mutex_enter(&spa_l2cache_lock);
1035 ASSERT(vd->vdev_isl2cache);
1036 spa_aux_activate(vd, &spa_l2cache_avl);
1037 mutex_exit(&spa_l2cache_lock);
1038 }
1039
1040 /*
1041 * ==========================================================================
1042 * SPA vdev locking
1043 * ==========================================================================
1044 */
1045
1046 /*
1047 * Lock the given spa_t for the purpose of adding or removing a vdev.
1048 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
1049 * It returns the next transaction group for the spa_t.
1050 */
1051 uint64_t
1052 spa_vdev_enter(spa_t *spa)
1053 {
1054 mutex_enter(&spa->spa_vdev_top_lock);
1055 mutex_enter(&spa_namespace_lock);
1056 return (spa_vdev_config_enter(spa));
1057 }
1058
1059 /*
1060 * Internal implementation for spa_vdev_enter(). Used when a vdev
1061 * operation requires multiple syncs (i.e. removing a device) while
1062 * keeping the spa_namespace_lock held.
1063 */
1064 uint64_t
1065 spa_vdev_config_enter(spa_t *spa)
1066 {
1067 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1068
1069 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1070
1071 return (spa_last_synced_txg(spa) + 1);
1072 }
1073
1074 /*
1075 * Used in combination with spa_vdev_config_enter() to allow the syncing
1076 * of multiple transactions without releasing the spa_namespace_lock.
1077 */
1078 void
1079 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
1080 {
1081 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1082
1083 int config_changed = B_FALSE;
1084
1085 ASSERT(txg > spa_last_synced_txg(spa));
1086
1087 spa->spa_pending_vdev = NULL;
1088
1089 /*
1090 * Reassess the DTLs.
1091 */
1092 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
1093
1094 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
1095 config_changed = B_TRUE;
1096 spa->spa_config_generation++;
1097 }
1098
1099 /*
1100 * Verify the metaslab classes.
1101 */
1102 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
1103 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
1104
1105 spa_config_exit(spa, SCL_ALL, spa);
1106
1107 /*
1108 * Panic the system if the specified tag requires it. This
1109 * is useful for ensuring that configurations are updated
1110 * transactionally.
1111 */
1112 if (zio_injection_enabled)
1113 zio_handle_panic_injection(spa, tag, 0);
1114
1115 /*
1116 * Note: this txg_wait_synced() is important because it ensures
1117 * that there won't be more than one config change per txg.
1118 * This allows us to use the txg as the generation number.
1119 */
1120 if (error == 0)
1121 txg_wait_synced(spa->spa_dsl_pool, txg);
1122
1123 if (vd != NULL) {
1124 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL);
1125 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1126 vdev_free(vd);
1127 spa_config_exit(spa, SCL_ALL, spa);
1128 }
1129
1130 /*
1131 * If the config changed, update the config cache.
1132 */
1133 if (config_changed)
1134 spa_config_sync(spa, B_FALSE, B_TRUE);
1135 }
1136
1137 /*
1138 * Unlock the spa_t after adding or removing a vdev. Besides undoing the
1139 * locking of spa_vdev_enter(), we also want make sure the transactions have
1140 * synced to disk, and then update the global configuration cache with the new
1141 * information.
1142 */
1143 int
1144 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
1145 {
1146 spa_vdev_config_exit(spa, vd, txg, error, FTAG);
1147 mutex_exit(&spa_namespace_lock);
1148 mutex_exit(&spa->spa_vdev_top_lock);
1149
1150 return (error);
1151 }
1152
1153 /*
1154 * Lock the given spa_t for the purpose of changing vdev state.
1155 */
1156 void
1157 spa_vdev_state_enter(spa_t *spa, int oplocks)
1158 {
1159 int locks = SCL_STATE_ALL | oplocks;
1160
1161 /*
1162 * Root pools may need to read of the underlying devfs filesystem
1163 * when opening up a vdev. Unfortunately if we're holding the
1164 * SCL_ZIO lock it will result in a deadlock when we try to issue
1165 * the read from the root filesystem. Instead we "prefetch"
1166 * the associated vnodes that we need prior to opening the
1167 * underlying devices and cache them so that we can prevent
1168 * any I/O when we are doing the actual open.
1169 */
1170 if (spa_is_root(spa)) {
1171 int low = locks & ~(SCL_ZIO - 1);
1172 int high = locks & ~low;
1173
1174 spa_config_enter(spa, high, spa, RW_WRITER);
1175 vdev_hold(spa->spa_root_vdev);
1176 spa_config_enter(spa, low, spa, RW_WRITER);
1177 } else {
1178 spa_config_enter(spa, locks, spa, RW_WRITER);
1179 }
1180 spa->spa_vdev_locks = locks;
1181 }
1182
1183 int
1184 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
1185 {
1186 boolean_t config_changed = B_FALSE;
1187
1188 if (vd != NULL || error == 0)
1189 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
1190 0, 0, B_FALSE);
1191
1192 if (vd != NULL) {
1193 vdev_state_dirty(vd->vdev_top);
1194 config_changed = B_TRUE;
1195 spa->spa_config_generation++;
1196 }
1197
1198 if (spa_is_root(spa))
1199 vdev_rele(spa->spa_root_vdev);
1200
1201 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1202 spa_config_exit(spa, spa->spa_vdev_locks, spa);
1203
1204 /*
1205 * If anything changed, wait for it to sync. This ensures that,
1206 * from the system administrator's perspective, zpool(1M) commands
1207 * are synchronous. This is important for things like zpool offline:
1208 * when the command completes, you expect no further I/O from ZFS.
1209 */
1210 if (vd != NULL)
1211 txg_wait_synced(spa->spa_dsl_pool, 0);
1212
1213 /*
1214 * If the config changed, update the config cache.
1215 */
1216 if (config_changed) {
1217 mutex_enter(&spa_namespace_lock);
1218 spa_config_sync(spa, B_FALSE, B_TRUE);
1219 mutex_exit(&spa_namespace_lock);
1220 }
1221
1222 return (error);
1223 }
1224
1225 /*
1226 * ==========================================================================
1227 * Miscellaneous functions
1228 * ==========================================================================
1229 */
1230
1231 void
1232 spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx)
1233 {
1234 if (!nvlist_exists(spa->spa_label_features, feature)) {
1235 fnvlist_add_boolean(spa->spa_label_features, feature);
1236 /*
1237 * When we are creating the pool (tx_txg==TXG_INITIAL), we can't
1238 * dirty the vdev config because lock SCL_CONFIG is not held.
1239 * Thankfully, in this case we don't need to dirty the config
1240 * because it will be written out anyway when we finish
1241 * creating the pool.
1242 */
1243 if (tx->tx_txg != TXG_INITIAL)
1244 vdev_config_dirty(spa->spa_root_vdev);
1245 }
1246 }
1247
1248 void
1249 spa_deactivate_mos_feature(spa_t *spa, const char *feature)
1250 {
1251 if (nvlist_remove_all(spa->spa_label_features, feature) == 0)
1252 vdev_config_dirty(spa->spa_root_vdev);
1253 }
1254
1255 /*
1256 * Rename a spa_t.
1257 */
1258 int
1259 spa_rename(const char *name, const char *newname)
1260 {
1261 spa_t *spa;
1262 int err;
1263
1264 /*
1265 * Lookup the spa_t and grab the config lock for writing. We need to
1266 * actually open the pool so that we can sync out the necessary labels.
1267 * It's OK to call spa_open() with the namespace lock held because we
1268 * allow recursive calls for other reasons.
1269 */
1270 mutex_enter(&spa_namespace_lock);
1271 if ((err = spa_open(name, &spa, FTAG)) != 0) {
1272 mutex_exit(&spa_namespace_lock);
1273 return (err);
1274 }
1275
1276 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1277
1278 avl_remove(&spa_namespace_avl, spa);
1279 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1280 avl_add(&spa_namespace_avl, spa);
1281
1282 /*
1283 * Sync all labels to disk with the new names by marking the root vdev
1284 * dirty and waiting for it to sync. It will pick up the new pool name
1285 * during the sync.
1286 */
1287 vdev_config_dirty(spa->spa_root_vdev);
1288
1289 spa_config_exit(spa, SCL_ALL, FTAG);
1290
1291 txg_wait_synced(spa->spa_dsl_pool, 0);
1292
1293 /*
1294 * Sync the updated config cache.
1295 */
1296 spa_config_sync(spa, B_FALSE, B_TRUE);
1297
1298 spa_close(spa, FTAG);
1299
1300 mutex_exit(&spa_namespace_lock);
1301
1302 return (0);
1303 }
1304
1305 /*
1306 * Return the spa_t associated with given pool_guid, if it exists. If
1307 * device_guid is non-zero, determine whether the pool exists *and* contains
1308 * a device with the specified device_guid.
1309 */
1310 spa_t *
1311 spa_by_guid(uint64_t pool_guid, uint64_t device_guid)
1312 {
1313 spa_t *spa;
1314 avl_tree_t *t = &spa_namespace_avl;
1315
1316 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1317
1318 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1319 if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1320 continue;
1321 if (spa->spa_root_vdev == NULL)
1322 continue;
1323 if (spa_guid(spa) == pool_guid) {
1324 if (device_guid == 0)
1325 break;
1326
1327 if (vdev_lookup_by_guid(spa->spa_root_vdev,
1328 device_guid) != NULL)
1329 break;
1330
1331 /*
1332 * Check any devices we may be in the process of adding.
1333 */
1334 if (spa->spa_pending_vdev) {
1335 if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1336 device_guid) != NULL)
1337 break;
1338 }
1339 }
1340 }
1341
1342 return (spa);
1343 }
1344
1345 /*
1346 * Determine whether a pool with the given pool_guid exists.
1347 */
1348 boolean_t
1349 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1350 {
1351 return (spa_by_guid(pool_guid, device_guid) != NULL);
1352 }
1353
1354 char *
1355 spa_strdup(const char *s)
1356 {
1357 size_t len;
1358 char *new;
1359
1360 len = strlen(s);
1361 new = kmem_alloc(len + 1, KM_SLEEP);
1362 bcopy(s, new, len);
1363 new[len] = '\0';
1364
1365 return (new);
1366 }
1367
1368 void
1369 spa_strfree(char *s)
1370 {
1371 kmem_free(s, strlen(s) + 1);
1372 }
1373
1374 uint64_t
1375 spa_get_random(uint64_t range)
1376 {
1377 uint64_t r;
1378
1379 ASSERT(range != 0);
1380
1381 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1382
1383 return (r % range);
1384 }
1385
1386 uint64_t
1387 spa_generate_guid(spa_t *spa)
1388 {
1389 uint64_t guid = spa_get_random(-1ULL);
1390
1391 if (spa != NULL) {
1392 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1393 guid = spa_get_random(-1ULL);
1394 } else {
1395 while (guid == 0 || spa_guid_exists(guid, 0))
1396 guid = spa_get_random(-1ULL);
1397 }
1398
1399 return (guid);
1400 }
1401
1402 void
1403 snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp)
1404 {
1405 char type[256];
1406 char *checksum = NULL;
1407 char *compress = NULL;
1408
1409 if (bp != NULL) {
1410 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) {
1411 dmu_object_byteswap_t bswap =
1412 DMU_OT_BYTESWAP(BP_GET_TYPE(bp));
1413 (void) snprintf(type, sizeof (type), "bswap %s %s",
1414 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ?
1415 "metadata" : "data",
1416 dmu_ot_byteswap[bswap].ob_name);
1417 } else {
1418 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name,
1419 sizeof (type));
1420 }
1421 if (!BP_IS_EMBEDDED(bp)) {
1422 checksum =
1423 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name;
1424 }
1425 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name;
1426 }
1427
1428 SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum,
1429 compress);
1430 }
1431
1432 void
1433 spa_freeze(spa_t *spa)
1434 {
1435 uint64_t freeze_txg = 0;
1436
1437 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1438 if (spa->spa_freeze_txg == UINT64_MAX) {
1439 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1440 spa->spa_freeze_txg = freeze_txg;
1441 }
1442 spa_config_exit(spa, SCL_ALL, FTAG);
1443 if (freeze_txg != 0)
1444 txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1445 }
1446
1447 void
1448 zfs_panic_recover(const char *fmt, ...)
1449 {
1450 va_list adx;
1451
1452 va_start(adx, fmt);
1453 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1454 va_end(adx);
1455 }
1456
1457 /*
1458 * This is a stripped-down version of strtoull, suitable only for converting
1459 * lowercase hexadecimal numbers that don't overflow.
1460 */
1461 uint64_t
1462 strtonum(const char *str, char **nptr)
1463 {
1464 uint64_t val = 0;
1465 char c;
1466 int digit;
1467
1468 while ((c = *str) != '\0') {
1469 if (c >= '0' && c <= '9')
1470 digit = c - '0';
1471 else if (c >= 'a' && c <= 'f')
1472 digit = 10 + c - 'a';
1473 else
1474 break;
1475
1476 val *= 16;
1477 val += digit;
1478
1479 str++;
1480 }
1481
1482 if (nptr)
1483 *nptr = (char *)str;
1484
1485 return (val);
1486 }
1487
1488 /*
1489 * ==========================================================================
1490 * Accessor functions
1491 * ==========================================================================
1492 */
1493
1494 boolean_t
1495 spa_shutting_down(spa_t *spa)
1496 {
1497 return (spa->spa_async_suspended);
1498 }
1499
1500 dsl_pool_t *
1501 spa_get_dsl(spa_t *spa)
1502 {
1503 return (spa->spa_dsl_pool);
1504 }
1505
1506 boolean_t
1507 spa_is_initializing(spa_t *spa)
1508 {
1509 return (spa->spa_is_initializing);
1510 }
1511
1512 blkptr_t *
1513 spa_get_rootblkptr(spa_t *spa)
1514 {
1515 return (&spa->spa_ubsync.ub_rootbp);
1516 }
1517
1518 void
1519 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1520 {
1521 spa->spa_uberblock.ub_rootbp = *bp;
1522 }
1523
1524 void
1525 spa_altroot(spa_t *spa, char *buf, size_t buflen)
1526 {
1527 if (spa->spa_root == NULL)
1528 buf[0] = '\0';
1529 else
1530 (void) strncpy(buf, spa->spa_root, buflen);
1531 }
1532
1533 int
1534 spa_sync_pass(spa_t *spa)
1535 {
1536 return (spa->spa_sync_pass);
1537 }
1538
1539 char *
1540 spa_name(spa_t *spa)
1541 {
1542 return (spa->spa_name);
1543 }
1544
1545 uint64_t
1546 spa_guid(spa_t *spa)
1547 {
1548 dsl_pool_t *dp = spa_get_dsl(spa);
1549 uint64_t guid;
1550
1551 /*
1552 * If we fail to parse the config during spa_load(), we can go through
1553 * the error path (which posts an ereport) and end up here with no root
1554 * vdev. We stash the original pool guid in 'spa_config_guid' to handle
1555 * this case.
1556 */
1557 if (spa->spa_root_vdev == NULL)
1558 return (spa->spa_config_guid);
1559
1560 guid = spa->spa_last_synced_guid != 0 ?
1561 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid;
1562
1563 /*
1564 * Return the most recently synced out guid unless we're
1565 * in syncing context.
1566 */
1567 if (dp && dsl_pool_sync_context(dp))
1568 return (spa->spa_root_vdev->vdev_guid);
1569 else
1570 return (guid);
1571 }
1572
1573 uint64_t
1574 spa_load_guid(spa_t *spa)
1575 {
1576 /*
1577 * This is a GUID that exists solely as a reference for the
1578 * purposes of the arc. It is generated at load time, and
1579 * is never written to persistent storage.
1580 */
1581 return (spa->spa_load_guid);
1582 }
1583
1584 uint64_t
1585 spa_last_synced_txg(spa_t *spa)
1586 {
1587 return (spa->spa_ubsync.ub_txg);
1588 }
1589
1590 uint64_t
1591 spa_first_txg(spa_t *spa)
1592 {
1593 return (spa->spa_first_txg);
1594 }
1595
1596 uint64_t
1597 spa_syncing_txg(spa_t *spa)
1598 {
1599 return (spa->spa_syncing_txg);
1600 }
1601
1602 pool_state_t
1603 spa_state(spa_t *spa)
1604 {
1605 return (spa->spa_state);
1606 }
1607
1608 spa_load_state_t
1609 spa_load_state(spa_t *spa)
1610 {
1611 return (spa->spa_load_state);
1612 }
1613
1614 uint64_t
1615 spa_freeze_txg(spa_t *spa)
1616 {
1617 return (spa->spa_freeze_txg);
1618 }
1619
1620 /* ARGSUSED */
1621 uint64_t
1622 spa_get_asize(spa_t *spa, uint64_t lsize)
1623 {
1624 return (lsize * spa_asize_inflation);
1625 }
1626
1627 /*
1628 * Return the amount of slop space in bytes. It is 1/32 of the pool (3.2%),
1629 * or at least 32MB.
1630 *
1631 * See the comment above spa_slop_shift for details.
1632 */
1633 uint64_t
1634 spa_get_slop_space(spa_t *spa) {
1635 uint64_t space = spa_get_dspace(spa);
1636 return (MAX(space >> spa_slop_shift, SPA_MINDEVSIZE >> 1));
1637 }
1638
1639 uint64_t
1640 spa_get_dspace(spa_t *spa)
1641 {
1642 return (spa->spa_dspace);
1643 }
1644
1645 void
1646 spa_update_dspace(spa_t *spa)
1647 {
1648 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1649 ddt_get_dedup_dspace(spa);
1650 }
1651
1652 /*
1653 * Return the failure mode that has been set to this pool. The default
1654 * behavior will be to block all I/Os when a complete failure occurs.
1655 */
1656 uint8_t
1657 spa_get_failmode(spa_t *spa)
1658 {
1659 return (spa->spa_failmode);
1660 }
1661
1662 boolean_t
1663 spa_suspended(spa_t *spa)
1664 {
1665 return (spa->spa_suspended);
1666 }
1667
1668 uint64_t
1669 spa_version(spa_t *spa)
1670 {
1671 return (spa->spa_ubsync.ub_version);
1672 }
1673
1674 boolean_t
1675 spa_deflate(spa_t *spa)
1676 {
1677 return (spa->spa_deflate);
1678 }
1679
1680 metaslab_class_t *
1681 spa_normal_class(spa_t *spa)
1682 {
1683 return (spa->spa_normal_class);
1684 }
1685
1686 metaslab_class_t *
1687 spa_log_class(spa_t *spa)
1688 {
1689 return (spa->spa_log_class);
1690 }
1691
1692 void
1693 spa_evicting_os_register(spa_t *spa, objset_t *os)
1694 {
1695 mutex_enter(&spa->spa_evicting_os_lock);
1696 list_insert_head(&spa->spa_evicting_os_list, os);
1697 mutex_exit(&spa->spa_evicting_os_lock);
1698 }
1699
1700 void
1701 spa_evicting_os_deregister(spa_t *spa, objset_t *os)
1702 {
1703 mutex_enter(&spa->spa_evicting_os_lock);
1704 list_remove(&spa->spa_evicting_os_list, os);
1705 cv_broadcast(&spa->spa_evicting_os_cv);
1706 mutex_exit(&spa->spa_evicting_os_lock);
1707 }
1708
1709 void
1710 spa_evicting_os_wait(spa_t *spa)
1711 {
1712 mutex_enter(&spa->spa_evicting_os_lock);
1713 while (!list_is_empty(&spa->spa_evicting_os_list))
1714 cv_wait(&spa->spa_evicting_os_cv, &spa->spa_evicting_os_lock);
1715 mutex_exit(&spa->spa_evicting_os_lock);
1716
1717 dmu_buf_user_evict_wait();
1718 }
1719
1720 int
1721 spa_max_replication(spa_t *spa)
1722 {
1723 /*
1724 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1725 * handle BPs with more than one DVA allocated. Set our max
1726 * replication level accordingly.
1727 */
1728 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1729 return (1);
1730 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1731 }
1732
1733 int
1734 spa_prev_software_version(spa_t *spa)
1735 {
1736 return (spa->spa_prev_software_version);
1737 }
1738
1739 uint64_t
1740 spa_deadman_synctime(spa_t *spa)
1741 {
1742 return (spa->spa_deadman_synctime);
1743 }
1744
1745 uint64_t
1746 dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1747 {
1748 uint64_t asize = DVA_GET_ASIZE(dva);
1749 uint64_t dsize = asize;
1750
1751 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1752
1753 if (asize != 0 && spa->spa_deflate) {
1754 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1755 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1756 }
1757
1758 return (dsize);
1759 }
1760
1761 uint64_t
1762 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1763 {
1764 uint64_t dsize = 0;
1765
1766 for (int d = 0; d < BP_GET_NDVAS(bp); d++)
1767 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1768
1769 return (dsize);
1770 }
1771
1772 uint64_t
1773 bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1774 {
1775 uint64_t dsize = 0;
1776
1777 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1778
1779 for (int d = 0; d < BP_GET_NDVAS(bp); d++)
1780 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1781
1782 spa_config_exit(spa, SCL_VDEV, FTAG);
1783
1784 return (dsize);
1785 }
1786
1787 /*
1788 * ==========================================================================
1789 * Initialization and Termination
1790 * ==========================================================================
1791 */
1792
1793 static int
1794 spa_name_compare(const void *a1, const void *a2)
1795 {
1796 const spa_t *s1 = a1;
1797 const spa_t *s2 = a2;
1798 int s;
1799
1800 s = strcmp(s1->spa_name, s2->spa_name);
1801 if (s > 0)
1802 return (1);
1803 if (s < 0)
1804 return (-1);
1805 return (0);
1806 }
1807
1808 int
1809 spa_busy(void)
1810 {
1811 return (spa_active_count);
1812 }
1813
1814 void
1815 spa_boot_init()
1816 {
1817 spa_config_load();
1818 }
1819
1820 void
1821 spa_init(int mode)
1822 {
1823 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1824 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1825 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1826 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1827
1828 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1829 offsetof(spa_t, spa_avl));
1830
1831 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1832 offsetof(spa_aux_t, aux_avl));
1833
1834 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1835 offsetof(spa_aux_t, aux_avl));
1836
1837 spa_mode_global = mode;
1838
1839 #ifdef _KERNEL
1840 spa_arch_init();
1841 #else
1842 if (spa_mode_global != FREAD && dprintf_find_string("watch")) {
1843 arc_procfd = open("/proc/self/ctl", O_WRONLY);
1844 if (arc_procfd == -1) {
1845 perror("could not enable watchpoints: "
1846 "opening /proc/self/ctl failed: ");
1847 } else {
1848 arc_watch = B_TRUE;
1849 }
1850 }
1851 #endif
1852
1853 refcount_init();
1854 unique_init();
1855 range_tree_init();
1856 zio_init();
1857 dmu_init();
1858 zil_init();
1859 vdev_cache_stat_init();
1860 zfs_prop_init();
1861 zpool_prop_init();
1862 zpool_feature_init();
1863 spa_config_load();
1864 l2arc_start();
1865 }
1866
1867 void
1868 spa_fini(void)
1869 {
1870 l2arc_stop();
1871
1872 spa_evict_all();
1873
1874 vdev_cache_stat_fini();
1875 zil_fini();
1876 dmu_fini();
1877 zio_fini();
1878 range_tree_fini();
1879 unique_fini();
1880 refcount_fini();
1881
1882 avl_destroy(&spa_namespace_avl);
1883 avl_destroy(&spa_spare_avl);
1884 avl_destroy(&spa_l2cache_avl);
1885
1886 cv_destroy(&spa_namespace_cv);
1887 mutex_destroy(&spa_namespace_lock);
1888 mutex_destroy(&spa_spare_lock);
1889 mutex_destroy(&spa_l2cache_lock);
1890 }
1891
1892 /*
1893 * Return whether this pool has slogs. No locking needed.
1894 * It's not a problem if the wrong answer is returned as it's only for
1895 * performance and not correctness
1896 */
1897 boolean_t
1898 spa_has_slogs(spa_t *spa)
1899 {
1900 return (spa->spa_log_class->mc_rotor != NULL);
1901 }
1902
1903 spa_log_state_t
1904 spa_get_log_state(spa_t *spa)
1905 {
1906 return (spa->spa_log_state);
1907 }
1908
1909 void
1910 spa_set_log_state(spa_t *spa, spa_log_state_t state)
1911 {
1912 spa->spa_log_state = state;
1913 }
1914
1915 boolean_t
1916 spa_is_root(spa_t *spa)
1917 {
1918 return (spa->spa_is_root);
1919 }
1920
1921 boolean_t
1922 spa_writeable(spa_t *spa)
1923 {
1924 return (!!(spa->spa_mode & FWRITE));
1925 }
1926
1927 /*
1928 * Returns true if there is a pending sync task in any of the current
1929 * syncing txg, the current quiescing txg, or the current open txg.
1930 */
1931 boolean_t
1932 spa_has_pending_synctask(spa_t *spa)
1933 {
1934 return (!txg_all_lists_empty(&spa->spa_dsl_pool->dp_sync_tasks));
1935 }
1936
1937 int
1938 spa_mode(spa_t *spa)
1939 {
1940 return (spa->spa_mode);
1941 }
1942
1943 uint64_t
1944 spa_bootfs(spa_t *spa)
1945 {
1946 return (spa->spa_bootfs);
1947 }
1948
1949 uint64_t
1950 spa_delegation(spa_t *spa)
1951 {
1952 return (spa->spa_delegation);
1953 }
1954
1955 objset_t *
1956 spa_meta_objset(spa_t *spa)
1957 {
1958 return (spa->spa_meta_objset);
1959 }
1960
1961 enum zio_checksum
1962 spa_dedup_checksum(spa_t *spa)
1963 {
1964 return (spa->spa_dedup_checksum);
1965 }
1966
1967 /*
1968 * Reset pool scan stat per scan pass (or reboot).
1969 */
1970 void
1971 spa_scan_stat_init(spa_t *spa)
1972 {
1973 /* data not stored on disk */
1974 spa->spa_scan_pass_start = gethrestime_sec();
1975 spa->spa_scan_pass_exam = 0;
1976 vdev_scan_stat_init(spa->spa_root_vdev);
1977 }
1978
1979 /*
1980 * Get scan stats for zpool status reports
1981 */
1982 int
1983 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps)
1984 {
1985 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL;
1986
1987 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE)
1988 return (SET_ERROR(ENOENT));
1989 bzero(ps, sizeof (pool_scan_stat_t));
1990
1991 /* data stored on disk */
1992 ps->pss_func = scn->scn_phys.scn_func;
1993 ps->pss_start_time = scn->scn_phys.scn_start_time;
1994 ps->pss_end_time = scn->scn_phys.scn_end_time;
1995 ps->pss_to_examine = scn->scn_phys.scn_to_examine;
1996 ps->pss_examined = scn->scn_phys.scn_examined;
1997 ps->pss_to_process = scn->scn_phys.scn_to_process;
1998 ps->pss_processed = scn->scn_phys.scn_processed;
1999 ps->pss_errors = scn->scn_phys.scn_errors;
2000 ps->pss_state = scn->scn_phys.scn_state;
2001
2002 /* data not stored on disk */
2003 ps->pss_pass_start = spa->spa_scan_pass_start;
2004 ps->pss_pass_exam = spa->spa_scan_pass_exam;
2005
2006 return (0);
2007 }
2008
2009 boolean_t
2010 spa_debug_enabled(spa_t *spa)
2011 {
2012 return (spa->spa_debug);
2013 }
2014
2015 int
2016 spa_maxblocksize(spa_t *spa)
2017 {
2018 if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS))
2019 return (SPA_MAXBLOCKSIZE);
2020 else
2021 return (SPA_OLD_MAXBLOCKSIZE);
2022 }