xref: /titanic_52/usr/src/uts/common/fs/zfs/spa_misc.c (revision dd51520e127b452179a2ce4ea3bd8dee949f9afe)
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  */
24 
25 #include <sys/zfs_context.h>
26 #include <sys/spa_impl.h>
27 #include <sys/zio.h>
28 #include <sys/zio_checksum.h>
29 #include <sys/zio_compress.h>
30 #include <sys/dmu.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/zap.h>
33 #include <sys/zil.h>
34 #include <sys/vdev_impl.h>
35 #include <sys/metaslab.h>
36 #include <sys/uberblock_impl.h>
37 #include <sys/txg.h>
38 #include <sys/avl.h>
39 #include <sys/unique.h>
40 #include <sys/dsl_pool.h>
41 #include <sys/dsl_dir.h>
42 #include <sys/dsl_prop.h>
43 #include <sys/dsl_scan.h>
44 #include <sys/fs/zfs.h>
45 #include <sys/metaslab_impl.h>
46 #include <sys/arc.h>
47 #include <sys/ddt.h>
48 #include "zfs_prop.h"
49 
50 /*
51  * SPA locking
52  *
53  * There are four basic locks for managing spa_t structures:
54  *
55  * spa_namespace_lock (global mutex)
56  *
57  *	This lock must be acquired to do any of the following:
58  *
59  *		- Lookup a spa_t by name
60  *		- Add or remove a spa_t from the namespace
61  *		- Increase spa_refcount from non-zero
62  *		- Check if spa_refcount is zero
63  *		- Rename a spa_t
64  *		- add/remove/attach/detach devices
65  *		- Held for the duration of create/destroy/import/export
66  *
67  *	It does not need to handle recursion.  A create or destroy may
68  *	reference objects (files or zvols) in other pools, but by
69  *	definition they must have an existing reference, and will never need
70  *	to lookup a spa_t by name.
71  *
72  * spa_refcount (per-spa refcount_t protected by mutex)
73  *
74  *	This reference count keep track of any active users of the spa_t.  The
75  *	spa_t cannot be destroyed or freed while this is non-zero.  Internally,
76  *	the refcount is never really 'zero' - opening a pool implicitly keeps
77  *	some references in the DMU.  Internally we check against spa_minref, but
78  *	present the image of a zero/non-zero value to consumers.
79  *
80  * spa_config_lock[] (per-spa array of rwlocks)
81  *
82  *	This protects the spa_t from config changes, and must be held in
83  *	the following circumstances:
84  *
85  *		- RW_READER to perform I/O to the spa
86  *		- RW_WRITER to change the vdev config
87  *
88  * The locking order is fairly straightforward:
89  *
90  *		spa_namespace_lock	->	spa_refcount
91  *
92  *	The namespace lock must be acquired to increase the refcount from 0
93  *	or to check if it is zero.
94  *
95  *		spa_refcount		->	spa_config_lock[]
96  *
97  *	There must be at least one valid reference on the spa_t to acquire
98  *	the config lock.
99  *
100  *		spa_namespace_lock	->	spa_config_lock[]
101  *
102  *	The namespace lock must always be taken before the config lock.
103  *
104  *
105  * The spa_namespace_lock can be acquired directly and is globally visible.
106  *
107  * The namespace is manipulated using the following functions, all of which
108  * require the spa_namespace_lock to be held.
109  *
110  *	spa_lookup()		Lookup a spa_t by name.
111  *
112  *	spa_add()		Create a new spa_t in the namespace.
113  *
114  *	spa_remove()		Remove a spa_t from the namespace.  This also
115  *				frees up any memory associated with the spa_t.
116  *
117  *	spa_next()		Returns the next spa_t in the system, or the
118  *				first if NULL is passed.
119  *
120  *	spa_evict_all()		Shutdown and remove all spa_t structures in
121  *				the system.
122  *
123  *	spa_guid_exists()	Determine whether a pool/device guid exists.
124  *
125  * The spa_refcount is manipulated using the following functions:
126  *
127  *	spa_open_ref()		Adds a reference to the given spa_t.  Must be
128  *				called with spa_namespace_lock held if the
129  *				refcount is currently zero.
130  *
131  *	spa_close()		Remove a reference from the spa_t.  This will
132  *				not free the spa_t or remove it from the
133  *				namespace.  No locking is required.
134  *
135  *	spa_refcount_zero()	Returns true if the refcount is currently
136  *				zero.  Must be called with spa_namespace_lock
137  *				held.
138  *
139  * The spa_config_lock[] is an array of rwlocks, ordered as follows:
140  * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
141  * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
142  *
143  * To read the configuration, it suffices to hold one of these locks as reader.
144  * To modify the configuration, you must hold all locks as writer.  To modify
145  * vdev state without altering the vdev tree's topology (e.g. online/offline),
146  * you must hold SCL_STATE and SCL_ZIO as writer.
147  *
148  * We use these distinct config locks to avoid recursive lock entry.
149  * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
150  * block allocations (SCL_ALLOC), which may require reading space maps
151  * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
152  *
153  * The spa config locks cannot be normal rwlocks because we need the
154  * ability to hand off ownership.  For example, SCL_ZIO is acquired
155  * by the issuing thread and later released by an interrupt thread.
156  * They do, however, obey the usual write-wanted semantics to prevent
157  * writer (i.e. system administrator) starvation.
158  *
159  * The lock acquisition rules are as follows:
160  *
161  * SCL_CONFIG
162  *	Protects changes to the vdev tree topology, such as vdev
163  *	add/remove/attach/detach.  Protects the dirty config list
164  *	(spa_config_dirty_list) and the set of spares and l2arc devices.
165  *
166  * SCL_STATE
167  *	Protects changes to pool state and vdev state, such as vdev
168  *	online/offline/fault/degrade/clear.  Protects the dirty state list
169  *	(spa_state_dirty_list) and global pool state (spa_state).
170  *
171  * SCL_ALLOC
172  *	Protects changes to metaslab groups and classes.
173  *	Held as reader by metaslab_alloc() and metaslab_claim().
174  *
175  * SCL_ZIO
176  *	Held by bp-level zios (those which have no io_vd upon entry)
177  *	to prevent changes to the vdev tree.  The bp-level zio implicitly
178  *	protects all of its vdev child zios, which do not hold SCL_ZIO.
179  *
180  * SCL_FREE
181  *	Protects changes to metaslab groups and classes.
182  *	Held as reader by metaslab_free().  SCL_FREE is distinct from
183  *	SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
184  *	blocks in zio_done() while another i/o that holds either
185  *	SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
186  *
187  * SCL_VDEV
188  *	Held as reader to prevent changes to the vdev tree during trivial
189  *	inquiries such as bp_get_dsize().  SCL_VDEV is distinct from the
190  *	other locks, and lower than all of them, to ensure that it's safe
191  *	to acquire regardless of caller context.
192  *
193  * In addition, the following rules apply:
194  *
195  * (a)	spa_props_lock protects pool properties, spa_config and spa_config_list.
196  *	The lock ordering is SCL_CONFIG > spa_props_lock.
197  *
198  * (b)	I/O operations on leaf vdevs.  For any zio operation that takes
199  *	an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
200  *	or zio_write_phys() -- the caller must ensure that the config cannot
201  *	cannot change in the interim, and that the vdev cannot be reopened.
202  *	SCL_STATE as reader suffices for both.
203  *
204  * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
205  *
206  *	spa_vdev_enter()	Acquire the namespace lock and the config lock
207  *				for writing.
208  *
209  *	spa_vdev_exit()		Release the config lock, wait for all I/O
210  *				to complete, sync the updated configs to the
211  *				cache, and release the namespace lock.
212  *
213  * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
214  * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
215  * locking is, always, based on spa_namespace_lock and spa_config_lock[].
216  *
217  * spa_rename() is also implemented within this file since is requires
218  * manipulation of the namespace.
219  */
220 
221 static avl_tree_t spa_namespace_avl;
222 kmutex_t spa_namespace_lock;
223 static kcondvar_t spa_namespace_cv;
224 static int spa_active_count;
225 int spa_max_replication_override = SPA_DVAS_PER_BP;
226 
227 static kmutex_t spa_spare_lock;
228 static avl_tree_t spa_spare_avl;
229 static kmutex_t spa_l2cache_lock;
230 static avl_tree_t spa_l2cache_avl;
231 
232 kmem_cache_t *spa_buffer_pool;
233 int spa_mode_global;
234 
235 #ifdef ZFS_DEBUG
236 /* Everything except dprintf is on by default in debug builds */
237 int zfs_flags = ~ZFS_DEBUG_DPRINTF;
238 #else
239 int zfs_flags = 0;
240 #endif
241 
242 /*
243  * zfs_recover can be set to nonzero to attempt to recover from
244  * otherwise-fatal errors, typically caused by on-disk corruption.  When
245  * set, calls to zfs_panic_recover() will turn into warning messages.
246  */
247 int zfs_recover = 0;
248 
249 
250 /*
251  * ==========================================================================
252  * SPA config locking
253  * ==========================================================================
254  */
255 static void
256 spa_config_lock_init(spa_t *spa)
257 {
258 	for (int i = 0; i < SCL_LOCKS; i++) {
259 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
260 		mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
261 		cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
262 		refcount_create(&scl->scl_count);
263 		scl->scl_writer = NULL;
264 		scl->scl_write_wanted = 0;
265 	}
266 }
267 
268 static void
269 spa_config_lock_destroy(spa_t *spa)
270 {
271 	for (int i = 0; i < SCL_LOCKS; i++) {
272 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
273 		mutex_destroy(&scl->scl_lock);
274 		cv_destroy(&scl->scl_cv);
275 		refcount_destroy(&scl->scl_count);
276 		ASSERT(scl->scl_writer == NULL);
277 		ASSERT(scl->scl_write_wanted == 0);
278 	}
279 }
280 
281 int
282 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
283 {
284 	for (int i = 0; i < SCL_LOCKS; i++) {
285 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
286 		if (!(locks & (1 << i)))
287 			continue;
288 		mutex_enter(&scl->scl_lock);
289 		if (rw == RW_READER) {
290 			if (scl->scl_writer || scl->scl_write_wanted) {
291 				mutex_exit(&scl->scl_lock);
292 				spa_config_exit(spa, locks ^ (1 << i), tag);
293 				return (0);
294 			}
295 		} else {
296 			ASSERT(scl->scl_writer != curthread);
297 			if (!refcount_is_zero(&scl->scl_count)) {
298 				mutex_exit(&scl->scl_lock);
299 				spa_config_exit(spa, locks ^ (1 << i), tag);
300 				return (0);
301 			}
302 			scl->scl_writer = curthread;
303 		}
304 		(void) refcount_add(&scl->scl_count, tag);
305 		mutex_exit(&scl->scl_lock);
306 	}
307 	return (1);
308 }
309 
310 void
311 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
312 {
313 	int wlocks_held = 0;
314 
315 	for (int i = 0; i < SCL_LOCKS; i++) {
316 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
317 		if (scl->scl_writer == curthread)
318 			wlocks_held |= (1 << i);
319 		if (!(locks & (1 << i)))
320 			continue;
321 		mutex_enter(&scl->scl_lock);
322 		if (rw == RW_READER) {
323 			while (scl->scl_writer || scl->scl_write_wanted) {
324 				cv_wait(&scl->scl_cv, &scl->scl_lock);
325 			}
326 		} else {
327 			ASSERT(scl->scl_writer != curthread);
328 			while (!refcount_is_zero(&scl->scl_count)) {
329 				scl->scl_write_wanted++;
330 				cv_wait(&scl->scl_cv, &scl->scl_lock);
331 				scl->scl_write_wanted--;
332 			}
333 			scl->scl_writer = curthread;
334 		}
335 		(void) refcount_add(&scl->scl_count, tag);
336 		mutex_exit(&scl->scl_lock);
337 	}
338 	ASSERT(wlocks_held <= locks);
339 }
340 
341 void
342 spa_config_exit(spa_t *spa, int locks, void *tag)
343 {
344 	for (int i = SCL_LOCKS - 1; i >= 0; i--) {
345 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
346 		if (!(locks & (1 << i)))
347 			continue;
348 		mutex_enter(&scl->scl_lock);
349 		ASSERT(!refcount_is_zero(&scl->scl_count));
350 		if (refcount_remove(&scl->scl_count, tag) == 0) {
351 			ASSERT(scl->scl_writer == NULL ||
352 			    scl->scl_writer == curthread);
353 			scl->scl_writer = NULL;	/* OK in either case */
354 			cv_broadcast(&scl->scl_cv);
355 		}
356 		mutex_exit(&scl->scl_lock);
357 	}
358 }
359 
360 int
361 spa_config_held(spa_t *spa, int locks, krw_t rw)
362 {
363 	int locks_held = 0;
364 
365 	for (int i = 0; i < SCL_LOCKS; i++) {
366 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
367 		if (!(locks & (1 << i)))
368 			continue;
369 		if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
370 		    (rw == RW_WRITER && scl->scl_writer == curthread))
371 			locks_held |= 1 << i;
372 	}
373 
374 	return (locks_held);
375 }
376 
377 /*
378  * ==========================================================================
379  * SPA namespace functions
380  * ==========================================================================
381  */
382 
383 /*
384  * Lookup the named spa_t in the AVL tree.  The spa_namespace_lock must be held.
385  * Returns NULL if no matching spa_t is found.
386  */
387 spa_t *
388 spa_lookup(const char *name)
389 {
390 	static spa_t search;	/* spa_t is large; don't allocate on stack */
391 	spa_t *spa;
392 	avl_index_t where;
393 	char c;
394 	char *cp;
395 
396 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
397 
398 	/*
399 	 * If it's a full dataset name, figure out the pool name and
400 	 * just use that.
401 	 */
402 	cp = strpbrk(name, "/@");
403 	if (cp) {
404 		c = *cp;
405 		*cp = '\0';
406 	}
407 
408 	(void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
409 	spa = avl_find(&spa_namespace_avl, &search, &where);
410 
411 	if (cp)
412 		*cp = c;
413 
414 	return (spa);
415 }
416 
417 /*
418  * Create an uninitialized spa_t with the given name.  Requires
419  * spa_namespace_lock.  The caller must ensure that the spa_t doesn't already
420  * exist by calling spa_lookup() first.
421  */
422 spa_t *
423 spa_add(const char *name, nvlist_t *config, const char *altroot)
424 {
425 	spa_t *spa;
426 	spa_config_dirent_t *dp;
427 
428 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
429 
430 	spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
431 
432 	mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
433 	mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
434 	mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
435 	mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
436 	mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL);
437 	mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
438 	mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
439 	mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
440 	mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL);
441 
442 	cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
443 	cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL);
444 	cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
445 	cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
446 
447 	for (int t = 0; t < TXG_SIZE; t++)
448 		bplist_create(&spa->spa_free_bplist[t]);
449 
450 	(void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
451 	spa->spa_state = POOL_STATE_UNINITIALIZED;
452 	spa->spa_freeze_txg = UINT64_MAX;
453 	spa->spa_final_txg = UINT64_MAX;
454 	spa->spa_load_max_txg = UINT64_MAX;
455 	spa->spa_proc = &p0;
456 	spa->spa_proc_state = SPA_PROC_NONE;
457 
458 	refcount_create(&spa->spa_refcount);
459 	spa_config_lock_init(spa);
460 
461 	avl_add(&spa_namespace_avl, spa);
462 
463 	/*
464 	 * Set the alternate root, if there is one.
465 	 */
466 	if (altroot) {
467 		spa->spa_root = spa_strdup(altroot);
468 		spa_active_count++;
469 	}
470 
471 	/*
472 	 * Every pool starts with the default cachefile
473 	 */
474 	list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
475 	    offsetof(spa_config_dirent_t, scd_link));
476 
477 	dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
478 	dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
479 	list_insert_head(&spa->spa_config_list, dp);
480 
481 	VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME,
482 	    KM_SLEEP) == 0);
483 
484 	if (config != NULL)
485 		VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
486 
487 	return (spa);
488 }
489 
490 /*
491  * Removes a spa_t from the namespace, freeing up any memory used.  Requires
492  * spa_namespace_lock.  This is called only after the spa_t has been closed and
493  * deactivated.
494  */
495 void
496 spa_remove(spa_t *spa)
497 {
498 	spa_config_dirent_t *dp;
499 
500 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
501 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
502 
503 	nvlist_free(spa->spa_config_splitting);
504 
505 	avl_remove(&spa_namespace_avl, spa);
506 	cv_broadcast(&spa_namespace_cv);
507 
508 	if (spa->spa_root) {
509 		spa_strfree(spa->spa_root);
510 		spa_active_count--;
511 	}
512 
513 	while ((dp = list_head(&spa->spa_config_list)) != NULL) {
514 		list_remove(&spa->spa_config_list, dp);
515 		if (dp->scd_path != NULL)
516 			spa_strfree(dp->scd_path);
517 		kmem_free(dp, sizeof (spa_config_dirent_t));
518 	}
519 
520 	list_destroy(&spa->spa_config_list);
521 
522 	nvlist_free(spa->spa_load_info);
523 	spa_config_set(spa, NULL);
524 
525 	refcount_destroy(&spa->spa_refcount);
526 
527 	spa_config_lock_destroy(spa);
528 
529 	for (int t = 0; t < TXG_SIZE; t++)
530 		bplist_destroy(&spa->spa_free_bplist[t]);
531 
532 	cv_destroy(&spa->spa_async_cv);
533 	cv_destroy(&spa->spa_proc_cv);
534 	cv_destroy(&spa->spa_scrub_io_cv);
535 	cv_destroy(&spa->spa_suspend_cv);
536 
537 	mutex_destroy(&spa->spa_async_lock);
538 	mutex_destroy(&spa->spa_errlist_lock);
539 	mutex_destroy(&spa->spa_errlog_lock);
540 	mutex_destroy(&spa->spa_history_lock);
541 	mutex_destroy(&spa->spa_proc_lock);
542 	mutex_destroy(&spa->spa_props_lock);
543 	mutex_destroy(&spa->spa_scrub_lock);
544 	mutex_destroy(&spa->spa_suspend_lock);
545 	mutex_destroy(&spa->spa_vdev_top_lock);
546 
547 	kmem_free(spa, sizeof (spa_t));
548 }
549 
550 /*
551  * Given a pool, return the next pool in the namespace, or NULL if there is
552  * none.  If 'prev' is NULL, return the first pool.
553  */
554 spa_t *
555 spa_next(spa_t *prev)
556 {
557 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
558 
559 	if (prev)
560 		return (AVL_NEXT(&spa_namespace_avl, prev));
561 	else
562 		return (avl_first(&spa_namespace_avl));
563 }
564 
565 /*
566  * ==========================================================================
567  * SPA refcount functions
568  * ==========================================================================
569  */
570 
571 /*
572  * Add a reference to the given spa_t.  Must have at least one reference, or
573  * have the namespace lock held.
574  */
575 void
576 spa_open_ref(spa_t *spa, void *tag)
577 {
578 	ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
579 	    MUTEX_HELD(&spa_namespace_lock));
580 	(void) refcount_add(&spa->spa_refcount, tag);
581 }
582 
583 /*
584  * Remove a reference to the given spa_t.  Must have at least one reference, or
585  * have the namespace lock held.
586  */
587 void
588 spa_close(spa_t *spa, void *tag)
589 {
590 	ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
591 	    MUTEX_HELD(&spa_namespace_lock));
592 	(void) refcount_remove(&spa->spa_refcount, tag);
593 }
594 
595 /*
596  * Check to see if the spa refcount is zero.  Must be called with
597  * spa_namespace_lock held.  We really compare against spa_minref, which is the
598  * number of references acquired when opening a pool
599  */
600 boolean_t
601 spa_refcount_zero(spa_t *spa)
602 {
603 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
604 
605 	return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
606 }
607 
608 /*
609  * ==========================================================================
610  * SPA spare and l2cache tracking
611  * ==========================================================================
612  */
613 
614 /*
615  * Hot spares and cache devices are tracked using the same code below,
616  * for 'auxiliary' devices.
617  */
618 
619 typedef struct spa_aux {
620 	uint64_t	aux_guid;
621 	uint64_t	aux_pool;
622 	avl_node_t	aux_avl;
623 	int		aux_count;
624 } spa_aux_t;
625 
626 static int
627 spa_aux_compare(const void *a, const void *b)
628 {
629 	const spa_aux_t *sa = a;
630 	const spa_aux_t *sb = b;
631 
632 	if (sa->aux_guid < sb->aux_guid)
633 		return (-1);
634 	else if (sa->aux_guid > sb->aux_guid)
635 		return (1);
636 	else
637 		return (0);
638 }
639 
640 void
641 spa_aux_add(vdev_t *vd, avl_tree_t *avl)
642 {
643 	avl_index_t where;
644 	spa_aux_t search;
645 	spa_aux_t *aux;
646 
647 	search.aux_guid = vd->vdev_guid;
648 	if ((aux = avl_find(avl, &search, &where)) != NULL) {
649 		aux->aux_count++;
650 	} else {
651 		aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
652 		aux->aux_guid = vd->vdev_guid;
653 		aux->aux_count = 1;
654 		avl_insert(avl, aux, where);
655 	}
656 }
657 
658 void
659 spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
660 {
661 	spa_aux_t search;
662 	spa_aux_t *aux;
663 	avl_index_t where;
664 
665 	search.aux_guid = vd->vdev_guid;
666 	aux = avl_find(avl, &search, &where);
667 
668 	ASSERT(aux != NULL);
669 
670 	if (--aux->aux_count == 0) {
671 		avl_remove(avl, aux);
672 		kmem_free(aux, sizeof (spa_aux_t));
673 	} else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
674 		aux->aux_pool = 0ULL;
675 	}
676 }
677 
678 boolean_t
679 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
680 {
681 	spa_aux_t search, *found;
682 
683 	search.aux_guid = guid;
684 	found = avl_find(avl, &search, NULL);
685 
686 	if (pool) {
687 		if (found)
688 			*pool = found->aux_pool;
689 		else
690 			*pool = 0ULL;
691 	}
692 
693 	if (refcnt) {
694 		if (found)
695 			*refcnt = found->aux_count;
696 		else
697 			*refcnt = 0;
698 	}
699 
700 	return (found != NULL);
701 }
702 
703 void
704 spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
705 {
706 	spa_aux_t search, *found;
707 	avl_index_t where;
708 
709 	search.aux_guid = vd->vdev_guid;
710 	found = avl_find(avl, &search, &where);
711 	ASSERT(found != NULL);
712 	ASSERT(found->aux_pool == 0ULL);
713 
714 	found->aux_pool = spa_guid(vd->vdev_spa);
715 }
716 
717 /*
718  * Spares are tracked globally due to the following constraints:
719  *
720  * 	- A spare may be part of multiple pools.
721  * 	- A spare may be added to a pool even if it's actively in use within
722  *	  another pool.
723  * 	- A spare in use in any pool can only be the source of a replacement if
724  *	  the target is a spare in the same pool.
725  *
726  * We keep track of all spares on the system through the use of a reference
727  * counted AVL tree.  When a vdev is added as a spare, or used as a replacement
728  * spare, then we bump the reference count in the AVL tree.  In addition, we set
729  * the 'vdev_isspare' member to indicate that the device is a spare (active or
730  * inactive).  When a spare is made active (used to replace a device in the
731  * pool), we also keep track of which pool its been made a part of.
732  *
733  * The 'spa_spare_lock' protects the AVL tree.  These functions are normally
734  * called under the spa_namespace lock as part of vdev reconfiguration.  The
735  * separate spare lock exists for the status query path, which does not need to
736  * be completely consistent with respect to other vdev configuration changes.
737  */
738 
739 static int
740 spa_spare_compare(const void *a, const void *b)
741 {
742 	return (spa_aux_compare(a, b));
743 }
744 
745 void
746 spa_spare_add(vdev_t *vd)
747 {
748 	mutex_enter(&spa_spare_lock);
749 	ASSERT(!vd->vdev_isspare);
750 	spa_aux_add(vd, &spa_spare_avl);
751 	vd->vdev_isspare = B_TRUE;
752 	mutex_exit(&spa_spare_lock);
753 }
754 
755 void
756 spa_spare_remove(vdev_t *vd)
757 {
758 	mutex_enter(&spa_spare_lock);
759 	ASSERT(vd->vdev_isspare);
760 	spa_aux_remove(vd, &spa_spare_avl);
761 	vd->vdev_isspare = B_FALSE;
762 	mutex_exit(&spa_spare_lock);
763 }
764 
765 boolean_t
766 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
767 {
768 	boolean_t found;
769 
770 	mutex_enter(&spa_spare_lock);
771 	found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
772 	mutex_exit(&spa_spare_lock);
773 
774 	return (found);
775 }
776 
777 void
778 spa_spare_activate(vdev_t *vd)
779 {
780 	mutex_enter(&spa_spare_lock);
781 	ASSERT(vd->vdev_isspare);
782 	spa_aux_activate(vd, &spa_spare_avl);
783 	mutex_exit(&spa_spare_lock);
784 }
785 
786 /*
787  * Level 2 ARC devices are tracked globally for the same reasons as spares.
788  * Cache devices currently only support one pool per cache device, and so
789  * for these devices the aux reference count is currently unused beyond 1.
790  */
791 
792 static int
793 spa_l2cache_compare(const void *a, const void *b)
794 {
795 	return (spa_aux_compare(a, b));
796 }
797 
798 void
799 spa_l2cache_add(vdev_t *vd)
800 {
801 	mutex_enter(&spa_l2cache_lock);
802 	ASSERT(!vd->vdev_isl2cache);
803 	spa_aux_add(vd, &spa_l2cache_avl);
804 	vd->vdev_isl2cache = B_TRUE;
805 	mutex_exit(&spa_l2cache_lock);
806 }
807 
808 void
809 spa_l2cache_remove(vdev_t *vd)
810 {
811 	mutex_enter(&spa_l2cache_lock);
812 	ASSERT(vd->vdev_isl2cache);
813 	spa_aux_remove(vd, &spa_l2cache_avl);
814 	vd->vdev_isl2cache = B_FALSE;
815 	mutex_exit(&spa_l2cache_lock);
816 }
817 
818 boolean_t
819 spa_l2cache_exists(uint64_t guid, uint64_t *pool)
820 {
821 	boolean_t found;
822 
823 	mutex_enter(&spa_l2cache_lock);
824 	found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
825 	mutex_exit(&spa_l2cache_lock);
826 
827 	return (found);
828 }
829 
830 void
831 spa_l2cache_activate(vdev_t *vd)
832 {
833 	mutex_enter(&spa_l2cache_lock);
834 	ASSERT(vd->vdev_isl2cache);
835 	spa_aux_activate(vd, &spa_l2cache_avl);
836 	mutex_exit(&spa_l2cache_lock);
837 }
838 
839 /*
840  * ==========================================================================
841  * SPA vdev locking
842  * ==========================================================================
843  */
844 
845 /*
846  * Lock the given spa_t for the purpose of adding or removing a vdev.
847  * Grabs the global spa_namespace_lock plus the spa config lock for writing.
848  * It returns the next transaction group for the spa_t.
849  */
850 uint64_t
851 spa_vdev_enter(spa_t *spa)
852 {
853 	mutex_enter(&spa->spa_vdev_top_lock);
854 	mutex_enter(&spa_namespace_lock);
855 	return (spa_vdev_config_enter(spa));
856 }
857 
858 /*
859  * Internal implementation for spa_vdev_enter().  Used when a vdev
860  * operation requires multiple syncs (i.e. removing a device) while
861  * keeping the spa_namespace_lock held.
862  */
863 uint64_t
864 spa_vdev_config_enter(spa_t *spa)
865 {
866 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
867 
868 	spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
869 
870 	return (spa_last_synced_txg(spa) + 1);
871 }
872 
873 /*
874  * Used in combination with spa_vdev_config_enter() to allow the syncing
875  * of multiple transactions without releasing the spa_namespace_lock.
876  */
877 void
878 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
879 {
880 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
881 
882 	int config_changed = B_FALSE;
883 
884 	ASSERT(txg > spa_last_synced_txg(spa));
885 
886 	spa->spa_pending_vdev = NULL;
887 
888 	/*
889 	 * Reassess the DTLs.
890 	 */
891 	vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
892 
893 	if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
894 		config_changed = B_TRUE;
895 		spa->spa_config_generation++;
896 	}
897 
898 	/*
899 	 * Verify the metaslab classes.
900 	 */
901 	ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
902 	ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
903 
904 	spa_config_exit(spa, SCL_ALL, spa);
905 
906 	/*
907 	 * Panic the system if the specified tag requires it.  This
908 	 * is useful for ensuring that configurations are updated
909 	 * transactionally.
910 	 */
911 	if (zio_injection_enabled)
912 		zio_handle_panic_injection(spa, tag, 0);
913 
914 	/*
915 	 * Note: this txg_wait_synced() is important because it ensures
916 	 * that there won't be more than one config change per txg.
917 	 * This allows us to use the txg as the generation number.
918 	 */
919 	if (error == 0)
920 		txg_wait_synced(spa->spa_dsl_pool, txg);
921 
922 	if (vd != NULL) {
923 		ASSERT(!vd->vdev_detached || vd->vdev_dtl_smo.smo_object == 0);
924 		spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
925 		vdev_free(vd);
926 		spa_config_exit(spa, SCL_ALL, spa);
927 	}
928 
929 	/*
930 	 * If the config changed, update the config cache.
931 	 */
932 	if (config_changed)
933 		spa_config_sync(spa, B_FALSE, B_TRUE);
934 }
935 
936 /*
937  * Unlock the spa_t after adding or removing a vdev.  Besides undoing the
938  * locking of spa_vdev_enter(), we also want make sure the transactions have
939  * synced to disk, and then update the global configuration cache with the new
940  * information.
941  */
942 int
943 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
944 {
945 	spa_vdev_config_exit(spa, vd, txg, error, FTAG);
946 	mutex_exit(&spa_namespace_lock);
947 	mutex_exit(&spa->spa_vdev_top_lock);
948 
949 	return (error);
950 }
951 
952 /*
953  * Lock the given spa_t for the purpose of changing vdev state.
954  */
955 void
956 spa_vdev_state_enter(spa_t *spa, int oplocks)
957 {
958 	int locks = SCL_STATE_ALL | oplocks;
959 
960 	/*
961 	 * Root pools may need to read of the underlying devfs filesystem
962 	 * when opening up a vdev.  Unfortunately if we're holding the
963 	 * SCL_ZIO lock it will result in a deadlock when we try to issue
964 	 * the read from the root filesystem.  Instead we "prefetch"
965 	 * the associated vnodes that we need prior to opening the
966 	 * underlying devices and cache them so that we can prevent
967 	 * any I/O when we are doing the actual open.
968 	 */
969 	if (spa_is_root(spa)) {
970 		int low = locks & ~(SCL_ZIO - 1);
971 		int high = locks & ~low;
972 
973 		spa_config_enter(spa, high, spa, RW_WRITER);
974 		vdev_hold(spa->spa_root_vdev);
975 		spa_config_enter(spa, low, spa, RW_WRITER);
976 	} else {
977 		spa_config_enter(spa, locks, spa, RW_WRITER);
978 	}
979 	spa->spa_vdev_locks = locks;
980 }
981 
982 int
983 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
984 {
985 	boolean_t config_changed = B_FALSE;
986 
987 	if (vd != NULL || error == 0)
988 		vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
989 		    0, 0, B_FALSE);
990 
991 	if (vd != NULL) {
992 		vdev_state_dirty(vd->vdev_top);
993 		config_changed = B_TRUE;
994 		spa->spa_config_generation++;
995 	}
996 
997 	if (spa_is_root(spa))
998 		vdev_rele(spa->spa_root_vdev);
999 
1000 	ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1001 	spa_config_exit(spa, spa->spa_vdev_locks, spa);
1002 
1003 	/*
1004 	 * If anything changed, wait for it to sync.  This ensures that,
1005 	 * from the system administrator's perspective, zpool(1M) commands
1006 	 * are synchronous.  This is important for things like zpool offline:
1007 	 * when the command completes, you expect no further I/O from ZFS.
1008 	 */
1009 	if (vd != NULL)
1010 		txg_wait_synced(spa->spa_dsl_pool, 0);
1011 
1012 	/*
1013 	 * If the config changed, update the config cache.
1014 	 */
1015 	if (config_changed) {
1016 		mutex_enter(&spa_namespace_lock);
1017 		spa_config_sync(spa, B_FALSE, B_TRUE);
1018 		mutex_exit(&spa_namespace_lock);
1019 	}
1020 
1021 	return (error);
1022 }
1023 
1024 /*
1025  * ==========================================================================
1026  * Miscellaneous functions
1027  * ==========================================================================
1028  */
1029 
1030 /*
1031  * Rename a spa_t.
1032  */
1033 int
1034 spa_rename(const char *name, const char *newname)
1035 {
1036 	spa_t *spa;
1037 	int err;
1038 
1039 	/*
1040 	 * Lookup the spa_t and grab the config lock for writing.  We need to
1041 	 * actually open the pool so that we can sync out the necessary labels.
1042 	 * It's OK to call spa_open() with the namespace lock held because we
1043 	 * allow recursive calls for other reasons.
1044 	 */
1045 	mutex_enter(&spa_namespace_lock);
1046 	if ((err = spa_open(name, &spa, FTAG)) != 0) {
1047 		mutex_exit(&spa_namespace_lock);
1048 		return (err);
1049 	}
1050 
1051 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1052 
1053 	avl_remove(&spa_namespace_avl, spa);
1054 	(void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1055 	avl_add(&spa_namespace_avl, spa);
1056 
1057 	/*
1058 	 * Sync all labels to disk with the new names by marking the root vdev
1059 	 * dirty and waiting for it to sync.  It will pick up the new pool name
1060 	 * during the sync.
1061 	 */
1062 	vdev_config_dirty(spa->spa_root_vdev);
1063 
1064 	spa_config_exit(spa, SCL_ALL, FTAG);
1065 
1066 	txg_wait_synced(spa->spa_dsl_pool, 0);
1067 
1068 	/*
1069 	 * Sync the updated config cache.
1070 	 */
1071 	spa_config_sync(spa, B_FALSE, B_TRUE);
1072 
1073 	spa_close(spa, FTAG);
1074 
1075 	mutex_exit(&spa_namespace_lock);
1076 
1077 	return (0);
1078 }
1079 
1080 /*
1081  * Return the spa_t associated with given pool_guid, if it exists.  If
1082  * device_guid is non-zero, determine whether the pool exists *and* contains
1083  * a device with the specified device_guid.
1084  */
1085 spa_t *
1086 spa_by_guid(uint64_t pool_guid, uint64_t device_guid)
1087 {
1088 	spa_t *spa;
1089 	avl_tree_t *t = &spa_namespace_avl;
1090 
1091 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1092 
1093 	for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1094 		if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1095 			continue;
1096 		if (spa->spa_root_vdev == NULL)
1097 			continue;
1098 		if (spa_guid(spa) == pool_guid) {
1099 			if (device_guid == 0)
1100 				break;
1101 
1102 			if (vdev_lookup_by_guid(spa->spa_root_vdev,
1103 			    device_guid) != NULL)
1104 				break;
1105 
1106 			/*
1107 			 * Check any devices we may be in the process of adding.
1108 			 */
1109 			if (spa->spa_pending_vdev) {
1110 				if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1111 				    device_guid) != NULL)
1112 					break;
1113 			}
1114 		}
1115 	}
1116 
1117 	return (spa);
1118 }
1119 
1120 /*
1121  * Determine whether a pool with the given pool_guid exists.
1122  */
1123 boolean_t
1124 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1125 {
1126 	return (spa_by_guid(pool_guid, device_guid) != NULL);
1127 }
1128 
1129 char *
1130 spa_strdup(const char *s)
1131 {
1132 	size_t len;
1133 	char *new;
1134 
1135 	len = strlen(s);
1136 	new = kmem_alloc(len + 1, KM_SLEEP);
1137 	bcopy(s, new, len);
1138 	new[len] = '\0';
1139 
1140 	return (new);
1141 }
1142 
1143 void
1144 spa_strfree(char *s)
1145 {
1146 	kmem_free(s, strlen(s) + 1);
1147 }
1148 
1149 uint64_t
1150 spa_get_random(uint64_t range)
1151 {
1152 	uint64_t r;
1153 
1154 	ASSERT(range != 0);
1155 
1156 	(void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1157 
1158 	return (r % range);
1159 }
1160 
1161 uint64_t
1162 spa_generate_guid(spa_t *spa)
1163 {
1164 	uint64_t guid = spa_get_random(-1ULL);
1165 
1166 	if (spa != NULL) {
1167 		while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1168 			guid = spa_get_random(-1ULL);
1169 	} else {
1170 		while (guid == 0 || spa_guid_exists(guid, 0))
1171 			guid = spa_get_random(-1ULL);
1172 	}
1173 
1174 	return (guid);
1175 }
1176 
1177 void
1178 sprintf_blkptr(char *buf, const blkptr_t *bp)
1179 {
1180 	char *type = NULL;
1181 	char *checksum = NULL;
1182 	char *compress = NULL;
1183 
1184 	if (bp != NULL) {
1185 		type = dmu_ot[BP_GET_TYPE(bp)].ot_name;
1186 		checksum = zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name;
1187 		compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name;
1188 	}
1189 
1190 	SPRINTF_BLKPTR(snprintf, ' ', buf, bp, type, checksum, compress);
1191 }
1192 
1193 void
1194 spa_freeze(spa_t *spa)
1195 {
1196 	uint64_t freeze_txg = 0;
1197 
1198 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1199 	if (spa->spa_freeze_txg == UINT64_MAX) {
1200 		freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1201 		spa->spa_freeze_txg = freeze_txg;
1202 	}
1203 	spa_config_exit(spa, SCL_ALL, FTAG);
1204 	if (freeze_txg != 0)
1205 		txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1206 }
1207 
1208 void
1209 zfs_panic_recover(const char *fmt, ...)
1210 {
1211 	va_list adx;
1212 
1213 	va_start(adx, fmt);
1214 	vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1215 	va_end(adx);
1216 }
1217 
1218 /*
1219  * This is a stripped-down version of strtoull, suitable only for converting
1220  * lowercase hexidecimal numbers that don't overflow.
1221  */
1222 uint64_t
1223 strtonum(const char *str, char **nptr)
1224 {
1225 	uint64_t val = 0;
1226 	char c;
1227 	int digit;
1228 
1229 	while ((c = *str) != '\0') {
1230 		if (c >= '0' && c <= '9')
1231 			digit = c - '0';
1232 		else if (c >= 'a' && c <= 'f')
1233 			digit = 10 + c - 'a';
1234 		else
1235 			break;
1236 
1237 		val *= 16;
1238 		val += digit;
1239 
1240 		str++;
1241 	}
1242 
1243 	if (nptr)
1244 		*nptr = (char *)str;
1245 
1246 	return (val);
1247 }
1248 
1249 /*
1250  * ==========================================================================
1251  * Accessor functions
1252  * ==========================================================================
1253  */
1254 
1255 boolean_t
1256 spa_shutting_down(spa_t *spa)
1257 {
1258 	return (spa->spa_async_suspended);
1259 }
1260 
1261 dsl_pool_t *
1262 spa_get_dsl(spa_t *spa)
1263 {
1264 	return (spa->spa_dsl_pool);
1265 }
1266 
1267 blkptr_t *
1268 spa_get_rootblkptr(spa_t *spa)
1269 {
1270 	return (&spa->spa_ubsync.ub_rootbp);
1271 }
1272 
1273 void
1274 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1275 {
1276 	spa->spa_uberblock.ub_rootbp = *bp;
1277 }
1278 
1279 void
1280 spa_altroot(spa_t *spa, char *buf, size_t buflen)
1281 {
1282 	if (spa->spa_root == NULL)
1283 		buf[0] = '\0';
1284 	else
1285 		(void) strncpy(buf, spa->spa_root, buflen);
1286 }
1287 
1288 int
1289 spa_sync_pass(spa_t *spa)
1290 {
1291 	return (spa->spa_sync_pass);
1292 }
1293 
1294 char *
1295 spa_name(spa_t *spa)
1296 {
1297 	return (spa->spa_name);
1298 }
1299 
1300 uint64_t
1301 spa_guid(spa_t *spa)
1302 {
1303 	/*
1304 	 * If we fail to parse the config during spa_load(), we can go through
1305 	 * the error path (which posts an ereport) and end up here with no root
1306 	 * vdev.  We stash the original pool guid in 'spa_load_guid' to handle
1307 	 * this case.
1308 	 */
1309 	if (spa->spa_root_vdev != NULL)
1310 		return (spa->spa_root_vdev->vdev_guid);
1311 	else
1312 		return (spa->spa_load_guid);
1313 }
1314 
1315 uint64_t
1316 spa_last_synced_txg(spa_t *spa)
1317 {
1318 	return (spa->spa_ubsync.ub_txg);
1319 }
1320 
1321 uint64_t
1322 spa_first_txg(spa_t *spa)
1323 {
1324 	return (spa->spa_first_txg);
1325 }
1326 
1327 uint64_t
1328 spa_syncing_txg(spa_t *spa)
1329 {
1330 	return (spa->spa_syncing_txg);
1331 }
1332 
1333 pool_state_t
1334 spa_state(spa_t *spa)
1335 {
1336 	return (spa->spa_state);
1337 }
1338 
1339 spa_load_state_t
1340 spa_load_state(spa_t *spa)
1341 {
1342 	return (spa->spa_load_state);
1343 }
1344 
1345 uint64_t
1346 spa_freeze_txg(spa_t *spa)
1347 {
1348 	return (spa->spa_freeze_txg);
1349 }
1350 
1351 /* ARGSUSED */
1352 uint64_t
1353 spa_get_asize(spa_t *spa, uint64_t lsize)
1354 {
1355 	/*
1356 	 * The worst case is single-sector max-parity RAID-Z blocks, in which
1357 	 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
1358 	 * times the size; so just assume that.  Add to this the fact that
1359 	 * we can have up to 3 DVAs per bp, and one more factor of 2 because
1360 	 * the block may be dittoed with up to 3 DVAs by ddt_sync().
1361 	 */
1362 	return (lsize * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2);
1363 }
1364 
1365 uint64_t
1366 spa_get_dspace(spa_t *spa)
1367 {
1368 	return (spa->spa_dspace);
1369 }
1370 
1371 void
1372 spa_update_dspace(spa_t *spa)
1373 {
1374 	spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1375 	    ddt_get_dedup_dspace(spa);
1376 }
1377 
1378 /*
1379  * Return the failure mode that has been set to this pool. The default
1380  * behavior will be to block all I/Os when a complete failure occurs.
1381  */
1382 uint8_t
1383 spa_get_failmode(spa_t *spa)
1384 {
1385 	return (spa->spa_failmode);
1386 }
1387 
1388 boolean_t
1389 spa_suspended(spa_t *spa)
1390 {
1391 	return (spa->spa_suspended);
1392 }
1393 
1394 uint64_t
1395 spa_version(spa_t *spa)
1396 {
1397 	return (spa->spa_ubsync.ub_version);
1398 }
1399 
1400 boolean_t
1401 spa_deflate(spa_t *spa)
1402 {
1403 	return (spa->spa_deflate);
1404 }
1405 
1406 metaslab_class_t *
1407 spa_normal_class(spa_t *spa)
1408 {
1409 	return (spa->spa_normal_class);
1410 }
1411 
1412 metaslab_class_t *
1413 spa_log_class(spa_t *spa)
1414 {
1415 	return (spa->spa_log_class);
1416 }
1417 
1418 int
1419 spa_max_replication(spa_t *spa)
1420 {
1421 	/*
1422 	 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1423 	 * handle BPs with more than one DVA allocated.  Set our max
1424 	 * replication level accordingly.
1425 	 */
1426 	if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1427 		return (1);
1428 	return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1429 }
1430 
1431 int
1432 spa_prev_software_version(spa_t *spa)
1433 {
1434 	return (spa->spa_prev_software_version);
1435 }
1436 
1437 uint64_t
1438 dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1439 {
1440 	uint64_t asize = DVA_GET_ASIZE(dva);
1441 	uint64_t dsize = asize;
1442 
1443 	ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1444 
1445 	if (asize != 0 && spa->spa_deflate) {
1446 		vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1447 		dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1448 	}
1449 
1450 	return (dsize);
1451 }
1452 
1453 uint64_t
1454 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1455 {
1456 	uint64_t dsize = 0;
1457 
1458 	for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1459 		dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1460 
1461 	return (dsize);
1462 }
1463 
1464 uint64_t
1465 bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1466 {
1467 	uint64_t dsize = 0;
1468 
1469 	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1470 
1471 	for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1472 		dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1473 
1474 	spa_config_exit(spa, SCL_VDEV, FTAG);
1475 
1476 	return (dsize);
1477 }
1478 
1479 /*
1480  * ==========================================================================
1481  * Initialization and Termination
1482  * ==========================================================================
1483  */
1484 
1485 static int
1486 spa_name_compare(const void *a1, const void *a2)
1487 {
1488 	const spa_t *s1 = a1;
1489 	const spa_t *s2 = a2;
1490 	int s;
1491 
1492 	s = strcmp(s1->spa_name, s2->spa_name);
1493 	if (s > 0)
1494 		return (1);
1495 	if (s < 0)
1496 		return (-1);
1497 	return (0);
1498 }
1499 
1500 int
1501 spa_busy(void)
1502 {
1503 	return (spa_active_count);
1504 }
1505 
1506 void
1507 spa_boot_init()
1508 {
1509 	spa_config_load();
1510 }
1511 
1512 void
1513 spa_init(int mode)
1514 {
1515 	mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1516 	mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1517 	mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1518 	cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1519 
1520 	avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1521 	    offsetof(spa_t, spa_avl));
1522 
1523 	avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1524 	    offsetof(spa_aux_t, aux_avl));
1525 
1526 	avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1527 	    offsetof(spa_aux_t, aux_avl));
1528 
1529 	spa_mode_global = mode;
1530 
1531 	refcount_init();
1532 	unique_init();
1533 	zio_init();
1534 	dmu_init();
1535 	zil_init();
1536 	vdev_cache_stat_init();
1537 	zfs_prop_init();
1538 	zpool_prop_init();
1539 	spa_config_load();
1540 	l2arc_start();
1541 }
1542 
1543 void
1544 spa_fini(void)
1545 {
1546 	l2arc_stop();
1547 
1548 	spa_evict_all();
1549 
1550 	vdev_cache_stat_fini();
1551 	zil_fini();
1552 	dmu_fini();
1553 	zio_fini();
1554 	unique_fini();
1555 	refcount_fini();
1556 
1557 	avl_destroy(&spa_namespace_avl);
1558 	avl_destroy(&spa_spare_avl);
1559 	avl_destroy(&spa_l2cache_avl);
1560 
1561 	cv_destroy(&spa_namespace_cv);
1562 	mutex_destroy(&spa_namespace_lock);
1563 	mutex_destroy(&spa_spare_lock);
1564 	mutex_destroy(&spa_l2cache_lock);
1565 }
1566 
1567 /*
1568  * Return whether this pool has slogs. No locking needed.
1569  * It's not a problem if the wrong answer is returned as it's only for
1570  * performance and not correctness
1571  */
1572 boolean_t
1573 spa_has_slogs(spa_t *spa)
1574 {
1575 	return (spa->spa_log_class->mc_rotor != NULL);
1576 }
1577 
1578 spa_log_state_t
1579 spa_get_log_state(spa_t *spa)
1580 {
1581 	return (spa->spa_log_state);
1582 }
1583 
1584 void
1585 spa_set_log_state(spa_t *spa, spa_log_state_t state)
1586 {
1587 	spa->spa_log_state = state;
1588 }
1589 
1590 boolean_t
1591 spa_is_root(spa_t *spa)
1592 {
1593 	return (spa->spa_is_root);
1594 }
1595 
1596 boolean_t
1597 spa_writeable(spa_t *spa)
1598 {
1599 	return (!!(spa->spa_mode & FWRITE));
1600 }
1601 
1602 int
1603 spa_mode(spa_t *spa)
1604 {
1605 	return (spa->spa_mode);
1606 }
1607 
1608 uint64_t
1609 spa_bootfs(spa_t *spa)
1610 {
1611 	return (spa->spa_bootfs);
1612 }
1613 
1614 uint64_t
1615 spa_delegation(spa_t *spa)
1616 {
1617 	return (spa->spa_delegation);
1618 }
1619 
1620 objset_t *
1621 spa_meta_objset(spa_t *spa)
1622 {
1623 	return (spa->spa_meta_objset);
1624 }
1625 
1626 enum zio_checksum
1627 spa_dedup_checksum(spa_t *spa)
1628 {
1629 	return (spa->spa_dedup_checksum);
1630 }
1631 
1632 /*
1633  * Reset pool scan stat per scan pass (or reboot).
1634  */
1635 void
1636 spa_scan_stat_init(spa_t *spa)
1637 {
1638 	/* data not stored on disk */
1639 	spa->spa_scan_pass_start = gethrestime_sec();
1640 	spa->spa_scan_pass_exam = 0;
1641 	vdev_scan_stat_init(spa->spa_root_vdev);
1642 }
1643 
1644 /*
1645  * Get scan stats for zpool status reports
1646  */
1647 int
1648 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps)
1649 {
1650 	dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL;
1651 
1652 	if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE)
1653 		return (ENOENT);
1654 	bzero(ps, sizeof (pool_scan_stat_t));
1655 
1656 	/* data stored on disk */
1657 	ps->pss_func = scn->scn_phys.scn_func;
1658 	ps->pss_start_time = scn->scn_phys.scn_start_time;
1659 	ps->pss_end_time = scn->scn_phys.scn_end_time;
1660 	ps->pss_to_examine = scn->scn_phys.scn_to_examine;
1661 	ps->pss_examined = scn->scn_phys.scn_examined;
1662 	ps->pss_to_process = scn->scn_phys.scn_to_process;
1663 	ps->pss_processed = scn->scn_phys.scn_processed;
1664 	ps->pss_errors = scn->scn_phys.scn_errors;
1665 	ps->pss_state = scn->scn_phys.scn_state;
1666 
1667 	/* data not stored on disk */
1668 	ps->pss_pass_start = spa->spa_scan_pass_start;
1669 	ps->pss_pass_exam = spa->spa_scan_pass_exam;
1670 
1671 	return (0);
1672 }
1673