1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25 */
26
27 #include <sys/zfs_context.h>
28 #include <sys/dmu.h>
29 #include <sys/dmu_tx.h>
30 #include <sys/space_map.h>
31 #include <sys/metaslab_impl.h>
32 #include <sys/vdev_impl.h>
33 #include <sys/zio.h>
34
35 /*
36 * Allow allocations to switch to gang blocks quickly. We do this to
37 * avoid having to load lots of space_maps in a given txg. There are,
38 * however, some cases where we want to avoid "fast" ganging and instead
39 * we want to do an exhaustive search of all metaslabs on this device.
40 * Currently we don't allow any gang, zil, or dump device related allocations
41 * to "fast" gang.
42 */
43 #define CAN_FASTGANG(flags) \
44 (!((flags) & (METASLAB_GANG_CHILD | METASLAB_GANG_HEADER | \
45 METASLAB_GANG_AVOID)))
46
47 uint64_t metaslab_aliquot = 512ULL << 10;
48 uint64_t metaslab_gang_bang = SPA_MAXBLOCKSIZE + 1; /* force gang blocks */
49
50 /*
51 * The in-core space map representation is more compact than its on-disk form.
52 * The zfs_condense_pct determines how much more compact the in-core
53 * space_map representation must be before we compact it on-disk.
54 * Values should be greater than or equal to 100.
55 */
56 int zfs_condense_pct = 200;
57
58 /*
59 * This value defines the number of allowed allocation failures per vdev.
60 * If a device reaches this threshold in a given txg then we consider skipping
61 * allocations on that device. The value of zfs_mg_alloc_failures is computed
62 * in zio_init() unless it has been overridden in /etc/system.
63 */
64 int zfs_mg_alloc_failures = 0;
65
66 /*
67 * The zfs_mg_noalloc_threshold defines which metaslab groups should
68 * be eligible for allocation. The value is defined as a percentage of
69 * a free space. Metaslab groups that have more free space than
70 * zfs_mg_noalloc_threshold are always eligible for allocations. Once
71 * a metaslab group's free space is less than or equal to the
72 * zfs_mg_noalloc_threshold the allocator will avoid allocating to that
73 * group unless all groups in the pool have reached zfs_mg_noalloc_threshold.
74 * Once all groups in the pool reach zfs_mg_noalloc_threshold then all
75 * groups are allowed to accept allocations. Gang blocks are always
76 * eligible to allocate on any metaslab group. The default value of 0 means
77 * no metaslab group will be excluded based on this criterion.
78 */
79 int zfs_mg_noalloc_threshold = 0;
80
81 /*
82 * Metaslab debugging: when set, keeps all space maps in core to verify frees.
83 */
84 static int metaslab_debug = 0;
85
86 /*
87 * Minimum size which forces the dynamic allocator to change
88 * it's allocation strategy. Once the space map cannot satisfy
89 * an allocation of this size then it switches to using more
90 * aggressive strategy (i.e search by size rather than offset).
91 */
92 uint64_t metaslab_df_alloc_threshold = SPA_MAXBLOCKSIZE;
93
94 /*
95 * The minimum free space, in percent, which must be available
96 * in a space map to continue allocations in a first-fit fashion.
97 * Once the space_map's free space drops below this level we dynamically
98 * switch to using best-fit allocations.
99 */
100 int metaslab_df_free_pct = 4;
101
102 /*
103 * A metaslab is considered "free" if it contains a contiguous
104 * segment which is greater than metaslab_min_alloc_size.
105 */
106 uint64_t metaslab_min_alloc_size = DMU_MAX_ACCESS;
107
108 /*
109 * Max number of space_maps to prefetch.
110 */
111 int metaslab_prefetch_limit = SPA_DVAS_PER_BP;
112
113 /*
114 * Percentage bonus multiplier for metaslabs that are in the bonus area.
115 */
116 int metaslab_smo_bonus_pct = 150;
117
118 /*
119 * Should we be willing to write data to degraded vdevs?
120 */
121 boolean_t zfs_write_to_degraded = B_FALSE;
122
123 /*
124 * ==========================================================================
125 * Metaslab classes
126 * ==========================================================================
127 */
128 metaslab_class_t *
129 metaslab_class_create(spa_t *spa, space_map_ops_t *ops)
130 {
131 metaslab_class_t *mc;
132
133 mc = kmem_zalloc(sizeof (metaslab_class_t), KM_SLEEP);
134
135 mc->mc_spa = spa;
136 mc->mc_rotor = NULL;
137 mc->mc_ops = ops;
138
139 return (mc);
140 }
141
142 void
143 metaslab_class_destroy(metaslab_class_t *mc)
144 {
145 ASSERT(mc->mc_rotor == NULL);
146 ASSERT(mc->mc_alloc == 0);
147 ASSERT(mc->mc_deferred == 0);
148 ASSERT(mc->mc_space == 0);
149 ASSERT(mc->mc_dspace == 0);
150
151 kmem_free(mc, sizeof (metaslab_class_t));
152 }
153
154 int
155 metaslab_class_validate(metaslab_class_t *mc)
156 {
157 metaslab_group_t *mg;
158 vdev_t *vd;
159
160 /*
161 * Must hold one of the spa_config locks.
162 */
163 ASSERT(spa_config_held(mc->mc_spa, SCL_ALL, RW_READER) ||
164 spa_config_held(mc->mc_spa, SCL_ALL, RW_WRITER));
165
166 if ((mg = mc->mc_rotor) == NULL)
167 return (0);
168
169 do {
170 vd = mg->mg_vd;
171 ASSERT(vd->vdev_mg != NULL);
172 ASSERT3P(vd->vdev_top, ==, vd);
173 ASSERT3P(mg->mg_class, ==, mc);
174 ASSERT3P(vd->vdev_ops, !=, &vdev_hole_ops);
175 } while ((mg = mg->mg_next) != mc->mc_rotor);
176
177 return (0);
178 }
179
180 void
181 metaslab_class_space_update(metaslab_class_t *mc, int64_t alloc_delta,
182 int64_t defer_delta, int64_t space_delta, int64_t dspace_delta)
183 {
184 atomic_add_64(&mc->mc_alloc, alloc_delta);
185 atomic_add_64(&mc->mc_deferred, defer_delta);
186 atomic_add_64(&mc->mc_space, space_delta);
187 atomic_add_64(&mc->mc_dspace, dspace_delta);
188 }
189
190 uint64_t
191 metaslab_class_get_alloc(metaslab_class_t *mc)
192 {
193 return (mc->mc_alloc);
194 }
195
196 uint64_t
197 metaslab_class_get_deferred(metaslab_class_t *mc)
198 {
199 return (mc->mc_deferred);
200 }
201
202 uint64_t
203 metaslab_class_get_space(metaslab_class_t *mc)
204 {
205 return (mc->mc_space);
206 }
207
208 uint64_t
209 metaslab_class_get_dspace(metaslab_class_t *mc)
210 {
211 return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space);
212 }
213
214 /*
215 * ==========================================================================
216 * Metaslab groups
217 * ==========================================================================
218 */
219 static int
220 metaslab_compare(const void *x1, const void *x2)
221 {
222 const metaslab_t *m1 = x1;
223 const metaslab_t *m2 = x2;
224
225 if (m1->ms_weight < m2->ms_weight)
226 return (1);
227 if (m1->ms_weight > m2->ms_weight)
228 return (-1);
229
230 /*
231 * If the weights are identical, use the offset to force uniqueness.
232 */
233 if (m1->ms_map->sm_start < m2->ms_map->sm_start)
234 return (-1);
235 if (m1->ms_map->sm_start > m2->ms_map->sm_start)
236 return (1);
237
238 ASSERT3P(m1, ==, m2);
239
240 return (0);
241 }
242
243 /*
244 * Update the allocatable flag and the metaslab group's capacity.
245 * The allocatable flag is set to true if the capacity is below
246 * the zfs_mg_noalloc_threshold. If a metaslab group transitions
247 * from allocatable to non-allocatable or vice versa then the metaslab
248 * group's class is updated to reflect the transition.
249 */
250 static void
251 metaslab_group_alloc_update(metaslab_group_t *mg)
252 {
253 vdev_t *vd = mg->mg_vd;
254 metaslab_class_t *mc = mg->mg_class;
255 vdev_stat_t *vs = &vd->vdev_stat;
256 boolean_t was_allocatable;
257
258 ASSERT(vd == vd->vdev_top);
259
260 mutex_enter(&mg->mg_lock);
261 was_allocatable = mg->mg_allocatable;
262
263 mg->mg_free_capacity = ((vs->vs_space - vs->vs_alloc) * 100) /
264 (vs->vs_space + 1);
265
266 mg->mg_allocatable = (mg->mg_free_capacity > zfs_mg_noalloc_threshold);
267
268 /*
269 * The mc_alloc_groups maintains a count of the number of
270 * groups in this metaslab class that are still above the
271 * zfs_mg_noalloc_threshold. This is used by the allocating
272 * threads to determine if they should avoid allocations to
273 * a given group. The allocator will avoid allocations to a group
274 * if that group has reached or is below the zfs_mg_noalloc_threshold
275 * and there are still other groups that are above the threshold.
276 * When a group transitions from allocatable to non-allocatable or
277 * vice versa we update the metaslab class to reflect that change.
278 * When the mc_alloc_groups value drops to 0 that means that all
279 * groups have reached the zfs_mg_noalloc_threshold making all groups
280 * eligible for allocations. This effectively means that all devices
281 * are balanced again.
282 */
283 if (was_allocatable && !mg->mg_allocatable)
284 mc->mc_alloc_groups--;
285 else if (!was_allocatable && mg->mg_allocatable)
286 mc->mc_alloc_groups++;
287 mutex_exit(&mg->mg_lock);
288 }
289
290 metaslab_group_t *
291 metaslab_group_create(metaslab_class_t *mc, vdev_t *vd)
292 {
293 metaslab_group_t *mg;
294
295 mg = kmem_zalloc(sizeof (metaslab_group_t), KM_SLEEP);
296 mutex_init(&mg->mg_lock, NULL, MUTEX_DEFAULT, NULL);
297 avl_create(&mg->mg_metaslab_tree, metaslab_compare,
298 sizeof (metaslab_t), offsetof(struct metaslab, ms_group_node));
299 mg->mg_vd = vd;
300 mg->mg_class = mc;
301 mg->mg_activation_count = 0;
302
303 return (mg);
304 }
305
306 void
307 metaslab_group_destroy(metaslab_group_t *mg)
308 {
309 ASSERT(mg->mg_prev == NULL);
310 ASSERT(mg->mg_next == NULL);
311 /*
312 * We may have gone below zero with the activation count
313 * either because we never activated in the first place or
314 * because we're done, and possibly removing the vdev.
315 */
316 ASSERT(mg->mg_activation_count <= 0);
317
318 avl_destroy(&mg->mg_metaslab_tree);
319 mutex_destroy(&mg->mg_lock);
320 kmem_free(mg, sizeof (metaslab_group_t));
321 }
322
323 void
324 metaslab_group_activate(metaslab_group_t *mg)
325 {
326 metaslab_class_t *mc = mg->mg_class;
327 metaslab_group_t *mgprev, *mgnext;
328
329 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
330
331 ASSERT(mc->mc_rotor != mg);
332 ASSERT(mg->mg_prev == NULL);
333 ASSERT(mg->mg_next == NULL);
334 ASSERT(mg->mg_activation_count <= 0);
335
336 if (++mg->mg_activation_count <= 0)
337 return;
338
339 mg->mg_aliquot = metaslab_aliquot * MAX(1, mg->mg_vd->vdev_children);
340 metaslab_group_alloc_update(mg);
341
342 if ((mgprev = mc->mc_rotor) == NULL) {
343 mg->mg_prev = mg;
344 mg->mg_next = mg;
345 } else {
346 mgnext = mgprev->mg_next;
347 mg->mg_prev = mgprev;
348 mg->mg_next = mgnext;
349 mgprev->mg_next = mg;
350 mgnext->mg_prev = mg;
351 }
352 mc->mc_rotor = mg;
353 }
354
355 void
356 metaslab_group_passivate(metaslab_group_t *mg)
357 {
358 metaslab_class_t *mc = mg->mg_class;
359 metaslab_group_t *mgprev, *mgnext;
360
361 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
362
363 if (--mg->mg_activation_count != 0) {
364 ASSERT(mc->mc_rotor != mg);
365 ASSERT(mg->mg_prev == NULL);
366 ASSERT(mg->mg_next == NULL);
367 ASSERT(mg->mg_activation_count < 0);
368 return;
369 }
370
371 mgprev = mg->mg_prev;
372 mgnext = mg->mg_next;
373
374 if (mg == mgnext) {
375 mc->mc_rotor = NULL;
376 } else {
377 mc->mc_rotor = mgnext;
378 mgprev->mg_next = mgnext;
379 mgnext->mg_prev = mgprev;
380 }
381
382 mg->mg_prev = NULL;
383 mg->mg_next = NULL;
384 }
385
386 static void
387 metaslab_group_add(metaslab_group_t *mg, metaslab_t *msp)
388 {
389 mutex_enter(&mg->mg_lock);
390 ASSERT(msp->ms_group == NULL);
391 msp->ms_group = mg;
392 msp->ms_weight = 0;
393 avl_add(&mg->mg_metaslab_tree, msp);
394 mutex_exit(&mg->mg_lock);
395 }
396
397 static void
398 metaslab_group_remove(metaslab_group_t *mg, metaslab_t *msp)
399 {
400 mutex_enter(&mg->mg_lock);
401 ASSERT(msp->ms_group == mg);
402 avl_remove(&mg->mg_metaslab_tree, msp);
403 msp->ms_group = NULL;
404 mutex_exit(&mg->mg_lock);
405 }
406
407 static void
408 metaslab_group_sort(metaslab_group_t *mg, metaslab_t *msp, uint64_t weight)
409 {
410 /*
411 * Although in principle the weight can be any value, in
412 * practice we do not use values in the range [1, 510].
413 */
414 ASSERT(weight >= SPA_MINBLOCKSIZE-1 || weight == 0);
415 ASSERT(MUTEX_HELD(&msp->ms_lock));
416
417 mutex_enter(&mg->mg_lock);
418 ASSERT(msp->ms_group == mg);
419 avl_remove(&mg->mg_metaslab_tree, msp);
420 msp->ms_weight = weight;
421 avl_add(&mg->mg_metaslab_tree, msp);
422 mutex_exit(&mg->mg_lock);
423 }
424
425 /*
426 * Determine if a given metaslab group should skip allocations. A metaslab
427 * group should avoid allocations if its used capacity has crossed the
428 * zfs_mg_noalloc_threshold and there is at least one metaslab group
429 * that can still handle allocations.
430 */
431 static boolean_t
432 metaslab_group_allocatable(metaslab_group_t *mg)
433 {
434 vdev_t *vd = mg->mg_vd;
435 spa_t *spa = vd->vdev_spa;
436 metaslab_class_t *mc = mg->mg_class;
437
438 /*
439 * A metaslab group is considered allocatable if its free capacity
440 * is greater than the set value of zfs_mg_noalloc_threshold, it's
441 * associated with a slog, or there are no other metaslab groups
442 * with free capacity greater than zfs_mg_noalloc_threshold.
443 */
444 return (mg->mg_free_capacity > zfs_mg_noalloc_threshold ||
445 mc != spa_normal_class(spa) || mc->mc_alloc_groups == 0);
446 }
447
448 /*
449 * ==========================================================================
450 * Common allocator routines
451 * ==========================================================================
452 */
453 static int
454 metaslab_segsize_compare(const void *x1, const void *x2)
455 {
456 const space_seg_t *s1 = x1;
457 const space_seg_t *s2 = x2;
458 uint64_t ss_size1 = s1->ss_end - s1->ss_start;
459 uint64_t ss_size2 = s2->ss_end - s2->ss_start;
460
461 if (ss_size1 < ss_size2)
462 return (-1);
463 if (ss_size1 > ss_size2)
464 return (1);
465
466 if (s1->ss_start < s2->ss_start)
467 return (-1);
468 if (s1->ss_start > s2->ss_start)
469 return (1);
470
471 return (0);
472 }
473
474 /*
475 * This is a helper function that can be used by the allocator to find
476 * a suitable block to allocate. This will search the specified AVL
477 * tree looking for a block that matches the specified criteria.
478 */
479 static uint64_t
480 metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size,
481 uint64_t align)
482 {
483 space_seg_t *ss, ssearch;
484 avl_index_t where;
485
486 ssearch.ss_start = *cursor;
487 ssearch.ss_end = *cursor + size;
488
489 ss = avl_find(t, &ssearch, &where);
490 if (ss == NULL)
491 ss = avl_nearest(t, where, AVL_AFTER);
492
493 while (ss != NULL) {
494 uint64_t offset = P2ROUNDUP(ss->ss_start, align);
495
496 if (offset + size <= ss->ss_end) {
497 *cursor = offset + size;
498 return (offset);
499 }
500 ss = AVL_NEXT(t, ss);
501 }
502
503 /*
504 * If we know we've searched the whole map (*cursor == 0), give up.
505 * Otherwise, reset the cursor to the beginning and try again.
506 */
507 if (*cursor == 0)
508 return (-1ULL);
509
510 *cursor = 0;
511 return (metaslab_block_picker(t, cursor, size, align));
512 }
513
514 static void
515 metaslab_pp_load(space_map_t *sm)
516 {
517 space_seg_t *ss;
518
519 ASSERT(sm->sm_ppd == NULL);
520 sm->sm_ppd = kmem_zalloc(64 * sizeof (uint64_t), KM_SLEEP);
521
522 sm->sm_pp_root = kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
523 avl_create(sm->sm_pp_root, metaslab_segsize_compare,
524 sizeof (space_seg_t), offsetof(struct space_seg, ss_pp_node));
525
526 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
527 avl_add(sm->sm_pp_root, ss);
528 }
529
530 static void
531 metaslab_pp_unload(space_map_t *sm)
532 {
533 void *cookie = NULL;
534
535 kmem_free(sm->sm_ppd, 64 * sizeof (uint64_t));
536 sm->sm_ppd = NULL;
537
538 while (avl_destroy_nodes(sm->sm_pp_root, &cookie) != NULL) {
539 /* tear down the tree */
540 }
541
542 avl_destroy(sm->sm_pp_root);
543 kmem_free(sm->sm_pp_root, sizeof (avl_tree_t));
544 sm->sm_pp_root = NULL;
545 }
546
547 /* ARGSUSED */
548 static void
549 metaslab_pp_claim(space_map_t *sm, uint64_t start, uint64_t size)
550 {
551 /* No need to update cursor */
552 }
553
554 /* ARGSUSED */
555 static void
556 metaslab_pp_free(space_map_t *sm, uint64_t start, uint64_t size)
557 {
558 /* No need to update cursor */
559 }
560
561 /*
562 * Return the maximum contiguous segment within the metaslab.
563 */
564 uint64_t
565 metaslab_pp_maxsize(space_map_t *sm)
566 {
567 avl_tree_t *t = sm->sm_pp_root;
568 space_seg_t *ss;
569
570 if (t == NULL || (ss = avl_last(t)) == NULL)
571 return (0ULL);
572
573 return (ss->ss_end - ss->ss_start);
574 }
575
576 /*
577 * ==========================================================================
578 * The first-fit block allocator
579 * ==========================================================================
580 */
581 static uint64_t
582 metaslab_ff_alloc(space_map_t *sm, uint64_t size)
583 {
584 avl_tree_t *t = &sm->sm_root;
585 uint64_t align = size & -size;
586 uint64_t *cursor = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
587
588 return (metaslab_block_picker(t, cursor, size, align));
589 }
590
591 /* ARGSUSED */
592 boolean_t
593 metaslab_ff_fragmented(space_map_t *sm)
594 {
595 return (B_TRUE);
596 }
597
598 static space_map_ops_t metaslab_ff_ops = {
599 metaslab_pp_load,
600 metaslab_pp_unload,
601 metaslab_ff_alloc,
602 metaslab_pp_claim,
603 metaslab_pp_free,
604 metaslab_pp_maxsize,
605 metaslab_ff_fragmented
606 };
607
608 /*
609 * ==========================================================================
610 * Dynamic block allocator -
611 * Uses the first fit allocation scheme until space get low and then
612 * adjusts to a best fit allocation method. Uses metaslab_df_alloc_threshold
613 * and metaslab_df_free_pct to determine when to switch the allocation scheme.
614 * ==========================================================================
615 */
616 static uint64_t
617 metaslab_df_alloc(space_map_t *sm, uint64_t size)
618 {
619 avl_tree_t *t = &sm->sm_root;
620 uint64_t align = size & -size;
621 uint64_t *cursor = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
622 uint64_t max_size = metaslab_pp_maxsize(sm);
623 int free_pct = sm->sm_space * 100 / sm->sm_size;
624
625 ASSERT(MUTEX_HELD(sm->sm_lock));
626 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
627
628 if (max_size < size)
629 return (-1ULL);
630
631 /*
632 * If we're running low on space switch to using the size
633 * sorted AVL tree (best-fit).
634 */
635 if (max_size < metaslab_df_alloc_threshold ||
636 free_pct < metaslab_df_free_pct) {
637 t = sm->sm_pp_root;
638 *cursor = 0;
639 }
640
641 return (metaslab_block_picker(t, cursor, size, 1ULL));
642 }
643
644 static boolean_t
645 metaslab_df_fragmented(space_map_t *sm)
646 {
647 uint64_t max_size = metaslab_pp_maxsize(sm);
648 int free_pct = sm->sm_space * 100 / sm->sm_size;
649
650 if (max_size >= metaslab_df_alloc_threshold &&
651 free_pct >= metaslab_df_free_pct)
652 return (B_FALSE);
653
654 return (B_TRUE);
655 }
656
657 static space_map_ops_t metaslab_df_ops = {
658 metaslab_pp_load,
659 metaslab_pp_unload,
660 metaslab_df_alloc,
661 metaslab_pp_claim,
662 metaslab_pp_free,
663 metaslab_pp_maxsize,
664 metaslab_df_fragmented
665 };
666
667 /*
668 * ==========================================================================
669 * Other experimental allocators
670 * ==========================================================================
671 */
672 static uint64_t
673 metaslab_cdf_alloc(space_map_t *sm, uint64_t size)
674 {
675 avl_tree_t *t = &sm->sm_root;
676 uint64_t *cursor = (uint64_t *)sm->sm_ppd;
677 uint64_t *extent_end = (uint64_t *)sm->sm_ppd + 1;
678 uint64_t max_size = metaslab_pp_maxsize(sm);
679 uint64_t rsize = size;
680 uint64_t offset = 0;
681
682 ASSERT(MUTEX_HELD(sm->sm_lock));
683 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
684
685 if (max_size < size)
686 return (-1ULL);
687
688 ASSERT3U(*extent_end, >=, *cursor);
689
690 /*
691 * If we're running low on space switch to using the size
692 * sorted AVL tree (best-fit).
693 */
694 if ((*cursor + size) > *extent_end) {
695
696 t = sm->sm_pp_root;
697 *cursor = *extent_end = 0;
698
699 if (max_size > 2 * SPA_MAXBLOCKSIZE)
700 rsize = MIN(metaslab_min_alloc_size, max_size);
701 offset = metaslab_block_picker(t, extent_end, rsize, 1ULL);
702 if (offset != -1)
703 *cursor = offset + size;
704 } else {
705 offset = metaslab_block_picker(t, cursor, rsize, 1ULL);
706 }
707 ASSERT3U(*cursor, <=, *extent_end);
708 return (offset);
709 }
710
711 static boolean_t
712 metaslab_cdf_fragmented(space_map_t *sm)
713 {
714 uint64_t max_size = metaslab_pp_maxsize(sm);
715
716 if (max_size > (metaslab_min_alloc_size * 10))
717 return (B_FALSE);
718 return (B_TRUE);
719 }
720
721 static space_map_ops_t metaslab_cdf_ops = {
722 metaslab_pp_load,
723 metaslab_pp_unload,
724 metaslab_cdf_alloc,
725 metaslab_pp_claim,
726 metaslab_pp_free,
727 metaslab_pp_maxsize,
728 metaslab_cdf_fragmented
729 };
730
731 uint64_t metaslab_ndf_clump_shift = 4;
732
733 static uint64_t
734 metaslab_ndf_alloc(space_map_t *sm, uint64_t size)
735 {
736 avl_tree_t *t = &sm->sm_root;
737 avl_index_t where;
738 space_seg_t *ss, ssearch;
739 uint64_t hbit = highbit(size);
740 uint64_t *cursor = (uint64_t *)sm->sm_ppd + hbit - 1;
741 uint64_t max_size = metaslab_pp_maxsize(sm);
742
743 ASSERT(MUTEX_HELD(sm->sm_lock));
744 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
745
746 if (max_size < size)
747 return (-1ULL);
748
749 ssearch.ss_start = *cursor;
750 ssearch.ss_end = *cursor + size;
751
752 ss = avl_find(t, &ssearch, &where);
753 if (ss == NULL || (ss->ss_start + size > ss->ss_end)) {
754 t = sm->sm_pp_root;
755
756 ssearch.ss_start = 0;
757 ssearch.ss_end = MIN(max_size,
758 1ULL << (hbit + metaslab_ndf_clump_shift));
759 ss = avl_find(t, &ssearch, &where);
760 if (ss == NULL)
761 ss = avl_nearest(t, where, AVL_AFTER);
762 ASSERT(ss != NULL);
763 }
764
765 if (ss != NULL) {
766 if (ss->ss_start + size <= ss->ss_end) {
767 *cursor = ss->ss_start + size;
768 return (ss->ss_start);
769 }
770 }
771 return (-1ULL);
772 }
773
774 static boolean_t
775 metaslab_ndf_fragmented(space_map_t *sm)
776 {
777 uint64_t max_size = metaslab_pp_maxsize(sm);
778
779 if (max_size > (metaslab_min_alloc_size << metaslab_ndf_clump_shift))
780 return (B_FALSE);
781 return (B_TRUE);
782 }
783
784
785 static space_map_ops_t metaslab_ndf_ops = {
786 metaslab_pp_load,
787 metaslab_pp_unload,
788 metaslab_ndf_alloc,
789 metaslab_pp_claim,
790 metaslab_pp_free,
791 metaslab_pp_maxsize,
792 metaslab_ndf_fragmented
793 };
794
795 space_map_ops_t *zfs_metaslab_ops = &metaslab_df_ops;
796
797 /*
798 * ==========================================================================
799 * Metaslabs
800 * ==========================================================================
801 */
802 metaslab_t *
803 metaslab_init(metaslab_group_t *mg, space_map_obj_t *smo,
804 uint64_t start, uint64_t size, uint64_t txg)
805 {
806 vdev_t *vd = mg->mg_vd;
807 metaslab_t *msp;
808
809 msp = kmem_zalloc(sizeof (metaslab_t), KM_SLEEP);
810 mutex_init(&msp->ms_lock, NULL, MUTEX_DEFAULT, NULL);
811
812 msp->ms_smo_syncing = *smo;
813
814 /*
815 * We create the main space map here, but we don't create the
816 * allocmaps and freemaps until metaslab_sync_done(). This serves
817 * two purposes: it allows metaslab_sync_done() to detect the
818 * addition of new space; and for debugging, it ensures that we'd
819 * data fault on any attempt to use this metaslab before it's ready.
820 */
821 msp->ms_map = kmem_zalloc(sizeof (space_map_t), KM_SLEEP);
822 space_map_create(msp->ms_map, start, size,
823 vd->vdev_ashift, &msp->ms_lock);
824
825 metaslab_group_add(mg, msp);
826
827 if (metaslab_debug && smo->smo_object != 0) {
828 mutex_enter(&msp->ms_lock);
829 VERIFY(space_map_load(msp->ms_map, mg->mg_class->mc_ops,
830 SM_FREE, smo, spa_meta_objset(vd->vdev_spa)) == 0);
831 mutex_exit(&msp->ms_lock);
832 }
833
834 /*
835 * If we're opening an existing pool (txg == 0) or creating
836 * a new one (txg == TXG_INITIAL), all space is available now.
837 * If we're adding space to an existing pool, the new space
838 * does not become available until after this txg has synced.
839 */
840 if (txg <= TXG_INITIAL)
841 metaslab_sync_done(msp, 0);
842
843 if (txg != 0) {
844 vdev_dirty(vd, 0, NULL, txg);
845 vdev_dirty(vd, VDD_METASLAB, msp, txg);
846 }
847
848 return (msp);
849 }
850
851 void
852 metaslab_fini(metaslab_t *msp)
853 {
854 metaslab_group_t *mg = msp->ms_group;
855
856 vdev_space_update(mg->mg_vd,
857 -msp->ms_smo.smo_alloc, 0, -msp->ms_map->sm_size);
858
859 metaslab_group_remove(mg, msp);
860
861 mutex_enter(&msp->ms_lock);
862
863 space_map_unload(msp->ms_map);
864 space_map_destroy(msp->ms_map);
865 kmem_free(msp->ms_map, sizeof (*msp->ms_map));
866
867 for (int t = 0; t < TXG_SIZE; t++) {
868 space_map_destroy(msp->ms_allocmap[t]);
869 space_map_destroy(msp->ms_freemap[t]);
870 kmem_free(msp->ms_allocmap[t], sizeof (*msp->ms_allocmap[t]));
871 kmem_free(msp->ms_freemap[t], sizeof (*msp->ms_freemap[t]));
872 }
873
874 for (int t = 0; t < TXG_DEFER_SIZE; t++) {
875 space_map_destroy(msp->ms_defermap[t]);
876 kmem_free(msp->ms_defermap[t], sizeof (*msp->ms_defermap[t]));
877 }
878
879 ASSERT0(msp->ms_deferspace);
880
881 mutex_exit(&msp->ms_lock);
882 mutex_destroy(&msp->ms_lock);
883
884 kmem_free(msp, sizeof (metaslab_t));
885 }
886
887 #define METASLAB_WEIGHT_PRIMARY (1ULL << 63)
888 #define METASLAB_WEIGHT_SECONDARY (1ULL << 62)
889 #define METASLAB_ACTIVE_MASK \
890 (METASLAB_WEIGHT_PRIMARY | METASLAB_WEIGHT_SECONDARY)
891
892 static uint64_t
893 metaslab_weight(metaslab_t *msp)
894 {
895 metaslab_group_t *mg = msp->ms_group;
896 space_map_t *sm = msp->ms_map;
897 space_map_obj_t *smo = &msp->ms_smo;
898 vdev_t *vd = mg->mg_vd;
899 uint64_t weight, space;
900
901 ASSERT(MUTEX_HELD(&msp->ms_lock));
902
903 /*
904 * This vdev is in the process of being removed so there is nothing
905 * for us to do here.
906 */
907 if (vd->vdev_removing) {
908 ASSERT0(smo->smo_alloc);
909 ASSERT0(vd->vdev_ms_shift);
910 return (0);
911 }
912
913 /*
914 * The baseline weight is the metaslab's free space.
915 */
916 space = sm->sm_size - smo->smo_alloc;
917 weight = space;
918
919 /*
920 * Modern disks have uniform bit density and constant angular velocity.
921 * Therefore, the outer recording zones are faster (higher bandwidth)
922 * than the inner zones by the ratio of outer to inner track diameter,
923 * which is typically around 2:1. We account for this by assigning
924 * higher weight to lower metaslabs (multiplier ranging from 2x to 1x).
925 * In effect, this means that we'll select the metaslab with the most
926 * free bandwidth rather than simply the one with the most free space.
927 */
928 weight = 2 * weight -
929 ((sm->sm_start >> vd->vdev_ms_shift) * weight) / vd->vdev_ms_count;
930 ASSERT(weight >= space && weight <= 2 * space);
931
932 /*
933 * For locality, assign higher weight to metaslabs which have
934 * a lower offset than what we've already activated.
935 */
936 if (sm->sm_start <= mg->mg_bonus_area)
937 weight *= (metaslab_smo_bonus_pct / 100);
938 ASSERT(weight >= space &&
939 weight <= 2 * (metaslab_smo_bonus_pct / 100) * space);
940
941 if (sm->sm_loaded && !sm->sm_ops->smop_fragmented(sm)) {
942 /*
943 * If this metaslab is one we're actively using, adjust its
944 * weight to make it preferable to any inactive metaslab so
945 * we'll polish it off.
946 */
947 weight |= (msp->ms_weight & METASLAB_ACTIVE_MASK);
948 }
949 return (weight);
950 }
951
952 static void
953 metaslab_prefetch(metaslab_group_t *mg)
954 {
955 spa_t *spa = mg->mg_vd->vdev_spa;
956 metaslab_t *msp;
957 avl_tree_t *t = &mg->mg_metaslab_tree;
958 int m;
959
960 mutex_enter(&mg->mg_lock);
961
962 /*
963 * Prefetch the next potential metaslabs
964 */
965 for (msp = avl_first(t), m = 0; msp; msp = AVL_NEXT(t, msp), m++) {
966 space_map_t *sm = msp->ms_map;
967 space_map_obj_t *smo = &msp->ms_smo;
968
969 /* If we have reached our prefetch limit then we're done */
970 if (m >= metaslab_prefetch_limit)
971 break;
972
973 if (!sm->sm_loaded && smo->smo_object != 0) {
974 mutex_exit(&mg->mg_lock);
975 dmu_prefetch(spa_meta_objset(spa), smo->smo_object,
976 0ULL, smo->smo_objsize);
977 mutex_enter(&mg->mg_lock);
978 }
979 }
980 mutex_exit(&mg->mg_lock);
981 }
982
983 static int
984 metaslab_activate(metaslab_t *msp, uint64_t activation_weight)
985 {
986 metaslab_group_t *mg = msp->ms_group;
987 space_map_t *sm = msp->ms_map;
988 space_map_ops_t *sm_ops = msp->ms_group->mg_class->mc_ops;
989
990 ASSERT(MUTEX_HELD(&msp->ms_lock));
991
992 if ((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
993 space_map_load_wait(sm);
994 if (!sm->sm_loaded) {
995 space_map_obj_t *smo = &msp->ms_smo;
996
997 int error = space_map_load(sm, sm_ops, SM_FREE, smo,
998 spa_meta_objset(msp->ms_group->mg_vd->vdev_spa));
999 if (error) {
1000 metaslab_group_sort(msp->ms_group, msp, 0);
1001 return (error);
1002 }
1003 for (int t = 0; t < TXG_DEFER_SIZE; t++)
1004 space_map_walk(msp->ms_defermap[t],
1005 space_map_claim, sm);
1006
1007 }
1008
1009 /*
1010 * Track the bonus area as we activate new metaslabs.
1011 */
1012 if (sm->sm_start > mg->mg_bonus_area) {
1013 mutex_enter(&mg->mg_lock);
1014 mg->mg_bonus_area = sm->sm_start;
1015 mutex_exit(&mg->mg_lock);
1016 }
1017
1018 metaslab_group_sort(msp->ms_group, msp,
1019 msp->ms_weight | activation_weight);
1020 }
1021 ASSERT(sm->sm_loaded);
1022 ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK);
1023
1024 return (0);
1025 }
1026
1027 static void
1028 metaslab_passivate(metaslab_t *msp, uint64_t size)
1029 {
1030 /*
1031 * If size < SPA_MINBLOCKSIZE, then we will not allocate from
1032 * this metaslab again. In that case, it had better be empty,
1033 * or we would be leaving space on the table.
1034 */
1035 ASSERT(size >= SPA_MINBLOCKSIZE || msp->ms_map->sm_space == 0);
1036 metaslab_group_sort(msp->ms_group, msp, MIN(msp->ms_weight, size));
1037 ASSERT((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0);
1038 }
1039
1040 /*
1041 * Determine if the in-core space map representation can be condensed on-disk.
1042 * We would like to use the following criteria to make our decision:
1043 *
1044 * 1. The size of the space map object should not dramatically increase as a
1045 * result of writing out our in-core free map.
1046 *
1047 * 2. The minimal on-disk space map representation is zfs_condense_pct/100
1048 * times the size than the in-core representation (i.e. zfs_condense_pct = 110
1049 * and in-core = 1MB, minimal = 1.1.MB).
1050 *
1051 * Checking the first condition is tricky since we don't want to walk
1052 * the entire AVL tree calculating the estimated on-disk size. Instead we
1053 * use the size-ordered AVL tree in the space map and calculate the
1054 * size required for the largest segment in our in-core free map. If the
1055 * size required to represent that segment on disk is larger than the space
1056 * map object then we avoid condensing this map.
1057 *
1058 * To determine the second criterion we use a best-case estimate and assume
1059 * each segment can be represented on-disk as a single 64-bit entry. We refer
1060 * to this best-case estimate as the space map's minimal form.
1061 */
1062 static boolean_t
1063 metaslab_should_condense(metaslab_t *msp)
1064 {
1065 space_map_t *sm = msp->ms_map;
1066 space_map_obj_t *smo = &msp->ms_smo_syncing;
1067 space_seg_t *ss;
1068 uint64_t size, entries, segsz;
1069
1070 ASSERT(MUTEX_HELD(&msp->ms_lock));
1071 ASSERT(sm->sm_loaded);
1072
1073 /*
1074 * Use the sm_pp_root AVL tree, which is ordered by size, to obtain
1075 * the largest segment in the in-core free map. If the tree is
1076 * empty then we should condense the map.
1077 */
1078 ss = avl_last(sm->sm_pp_root);
1079 if (ss == NULL)
1080 return (B_TRUE);
1081
1082 /*
1083 * Calculate the number of 64-bit entries this segment would
1084 * require when written to disk. If this single segment would be
1085 * larger on-disk than the entire current on-disk structure, then
1086 * clearly condensing will increase the on-disk structure size.
1087 */
1088 size = (ss->ss_end - ss->ss_start) >> sm->sm_shift;
1089 entries = size / (MIN(size, SM_RUN_MAX));
1090 segsz = entries * sizeof (uint64_t);
1091
1092 return (segsz <= smo->smo_objsize &&
1093 smo->smo_objsize >= (zfs_condense_pct *
1094 sizeof (uint64_t) * avl_numnodes(&sm->sm_root)) / 100);
1095 }
1096
1097 /*
1098 * Condense the on-disk space map representation to its minimized form.
1099 * The minimized form consists of a small number of allocations followed by
1100 * the in-core free map.
1101 */
1102 static void
1103 metaslab_condense(metaslab_t *msp, uint64_t txg, dmu_tx_t *tx)
1104 {
1105 spa_t *spa = msp->ms_group->mg_vd->vdev_spa;
1106 space_map_t *freemap = msp->ms_freemap[txg & TXG_MASK];
1107 space_map_t condense_map;
1108 space_map_t *sm = msp->ms_map;
1109 objset_t *mos = spa_meta_objset(spa);
1110 space_map_obj_t *smo = &msp->ms_smo_syncing;
1111
1112 ASSERT(MUTEX_HELD(&msp->ms_lock));
1113 ASSERT3U(spa_sync_pass(spa), ==, 1);
1114 ASSERT(sm->sm_loaded);
1115
1116 spa_dbgmsg(spa, "condensing: txg %llu, msp[%llu] %p, "
1117 "smo size %llu, segments %lu", txg,
1118 (msp->ms_map->sm_start / msp->ms_map->sm_size), msp,
1119 smo->smo_objsize, avl_numnodes(&sm->sm_root));
1120
1121 /*
1122 * Create an map that is a 100% allocated map. We remove segments
1123 * that have been freed in this txg, any deferred frees that exist,
1124 * and any allocation in the future. Removing segments should be
1125 * a relatively inexpensive operation since we expect these maps to
1126 * a small number of nodes.
1127 */
1128 space_map_create(&condense_map, sm->sm_start, sm->sm_size,
1129 sm->sm_shift, sm->sm_lock);
1130 space_map_add(&condense_map, condense_map.sm_start,
1131 condense_map.sm_size);
1132
1133 /*
1134 * Remove what's been freed in this txg from the condense_map.
1135 * Since we're in sync_pass 1, we know that all the frees from
1136 * this txg are in the freemap.
1137 */
1138 space_map_walk(freemap, space_map_remove, &condense_map);
1139
1140 for (int t = 0; t < TXG_DEFER_SIZE; t++)
1141 space_map_walk(msp->ms_defermap[t],
1142 space_map_remove, &condense_map);
1143
1144 for (int t = 1; t < TXG_CONCURRENT_STATES; t++)
1145 space_map_walk(msp->ms_allocmap[(txg + t) & TXG_MASK],
1146 space_map_remove, &condense_map);
1147
1148 /*
1149 * We're about to drop the metaslab's lock thus allowing
1150 * other consumers to change it's content. Set the
1151 * space_map's sm_condensing flag to ensure that
1152 * allocations on this metaslab do not occur while we're
1153 * in the middle of committing it to disk. This is only critical
1154 * for the ms_map as all other space_maps use per txg
1155 * views of their content.
1156 */
1157 sm->sm_condensing = B_TRUE;
1158
1159 mutex_exit(&msp->ms_lock);
1160 space_map_truncate(smo, mos, tx);
1161 mutex_enter(&msp->ms_lock);
1162
1163 /*
1164 * While we would ideally like to create a space_map representation
1165 * that consists only of allocation records, doing so can be
1166 * prohibitively expensive because the in-core free map can be
1167 * large, and therefore computationally expensive to subtract
1168 * from the condense_map. Instead we sync out two maps, a cheap
1169 * allocation only map followed by the in-core free map. While not
1170 * optimal, this is typically close to optimal, and much cheaper to
1171 * compute.
1172 */
1173 space_map_sync(&condense_map, SM_ALLOC, smo, mos, tx);
1174 space_map_vacate(&condense_map, NULL, NULL);
1175 space_map_destroy(&condense_map);
1176
1177 space_map_sync(sm, SM_FREE, smo, mos, tx);
1178 sm->sm_condensing = B_FALSE;
1179
1180 spa_dbgmsg(spa, "condensed: txg %llu, msp[%llu] %p, "
1181 "smo size %llu", txg,
1182 (msp->ms_map->sm_start / msp->ms_map->sm_size), msp,
1183 smo->smo_objsize);
1184 }
1185
1186 /*
1187 * Write a metaslab to disk in the context of the specified transaction group.
1188 */
1189 void
1190 metaslab_sync(metaslab_t *msp, uint64_t txg)
1191 {
1192 vdev_t *vd = msp->ms_group->mg_vd;
1193 spa_t *spa = vd->vdev_spa;
1194 objset_t *mos = spa_meta_objset(spa);
1195 space_map_t *allocmap = msp->ms_allocmap[txg & TXG_MASK];
1196 space_map_t **freemap = &msp->ms_freemap[txg & TXG_MASK];
1197 space_map_t **freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
1198 space_map_t *sm = msp->ms_map;
1199 space_map_obj_t *smo = &msp->ms_smo_syncing;
1200 dmu_buf_t *db;
1201 dmu_tx_t *tx;
1202
1203 ASSERT(!vd->vdev_ishole);
1204
1205 /*
1206 * This metaslab has just been added so there's no work to do now.
1207 */
1208 if (*freemap == NULL) {
1209 ASSERT3P(allocmap, ==, NULL);
1210 return;
1211 }
1212
1213 ASSERT3P(allocmap, !=, NULL);
1214 ASSERT3P(*freemap, !=, NULL);
1215 ASSERT3P(*freed_map, !=, NULL);
1216
1217 if (allocmap->sm_space == 0 && (*freemap)->sm_space == 0)
1218 return;
1219
1220 /*
1221 * The only state that can actually be changing concurrently with
1222 * metaslab_sync() is the metaslab's ms_map. No other thread can
1223 * be modifying this txg's allocmap, freemap, freed_map, or smo.
1224 * Therefore, we only hold ms_lock to satify space_map ASSERTs.
1225 * We drop it whenever we call into the DMU, because the DMU
1226 * can call down to us (e.g. via zio_free()) at any time.
1227 */
1228
1229 tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg);
1230
1231 if (smo->smo_object == 0) {
1232 ASSERT(smo->smo_objsize == 0);
1233 ASSERT(smo->smo_alloc == 0);
1234 smo->smo_object = dmu_object_alloc(mos,
1235 DMU_OT_SPACE_MAP, 1 << SPACE_MAP_BLOCKSHIFT,
1236 DMU_OT_SPACE_MAP_HEADER, sizeof (*smo), tx);
1237 ASSERT(smo->smo_object != 0);
1238 dmu_write(mos, vd->vdev_ms_array, sizeof (uint64_t) *
1239 (sm->sm_start >> vd->vdev_ms_shift),
1240 sizeof (uint64_t), &smo->smo_object, tx);
1241 }
1242
1243 mutex_enter(&msp->ms_lock);
1244
1245 if (sm->sm_loaded && spa_sync_pass(spa) == 1 &&
1246 metaslab_should_condense(msp)) {
1247 metaslab_condense(msp, txg, tx);
1248 } else {
1249 space_map_sync(allocmap, SM_ALLOC, smo, mos, tx);
1250 space_map_sync(*freemap, SM_FREE, smo, mos, tx);
1251 }
1252
1253 space_map_vacate(allocmap, NULL, NULL);
1254
1255 /*
1256 * For sync pass 1, we avoid walking the entire space map and
1257 * instead will just swap the pointers for freemap and
1258 * freed_map. We can safely do this since the freed_map is
1259 * guaranteed to be empty on the initial pass.
1260 */
1261 if (spa_sync_pass(spa) == 1) {
1262 ASSERT0((*freed_map)->sm_space);
1263 ASSERT0(avl_numnodes(&(*freed_map)->sm_root));
1264 space_map_swap(freemap, freed_map);
1265 } else {
1266 space_map_vacate(*freemap, space_map_add, *freed_map);
1267 }
1268
1269 ASSERT0(msp->ms_allocmap[txg & TXG_MASK]->sm_space);
1270 ASSERT0(msp->ms_freemap[txg & TXG_MASK]->sm_space);
1271
1272 mutex_exit(&msp->ms_lock);
1273
1274 VERIFY0(dmu_bonus_hold(mos, smo->smo_object, FTAG, &db));
1275 dmu_buf_will_dirty(db, tx);
1276 ASSERT3U(db->db_size, >=, sizeof (*smo));
1277 bcopy(smo, db->db_data, sizeof (*smo));
1278 dmu_buf_rele(db, FTAG);
1279
1280 dmu_tx_commit(tx);
1281 }
1282
1283 /*
1284 * Called after a transaction group has completely synced to mark
1285 * all of the metaslab's free space as usable.
1286 */
1287 void
1288 metaslab_sync_done(metaslab_t *msp, uint64_t txg)
1289 {
1290 space_map_obj_t *smo = &msp->ms_smo;
1291 space_map_obj_t *smosync = &msp->ms_smo_syncing;
1292 space_map_t *sm = msp->ms_map;
1293 space_map_t **freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
1294 space_map_t **defer_map = &msp->ms_defermap[txg % TXG_DEFER_SIZE];
1295 metaslab_group_t *mg = msp->ms_group;
1296 vdev_t *vd = mg->mg_vd;
1297 int64_t alloc_delta, defer_delta;
1298
1299 ASSERT(!vd->vdev_ishole);
1300
1301 mutex_enter(&msp->ms_lock);
1302
1303 /*
1304 * If this metaslab is just becoming available, initialize its
1305 * allocmaps, freemaps, and defermap and add its capacity to the vdev.
1306 */
1307 if (*freed_map == NULL) {
1308 ASSERT(*defer_map == NULL);
1309 for (int t = 0; t < TXG_SIZE; t++) {
1310 msp->ms_allocmap[t] = kmem_zalloc(sizeof (space_map_t),
1311 KM_SLEEP);
1312 space_map_create(msp->ms_allocmap[t], sm->sm_start,
1313 sm->sm_size, sm->sm_shift, sm->sm_lock);
1314 msp->ms_freemap[t] = kmem_zalloc(sizeof (space_map_t),
1315 KM_SLEEP);
1316 space_map_create(msp->ms_freemap[t], sm->sm_start,
1317 sm->sm_size, sm->sm_shift, sm->sm_lock);
1318 }
1319
1320 for (int t = 0; t < TXG_DEFER_SIZE; t++) {
1321 msp->ms_defermap[t] = kmem_zalloc(sizeof (space_map_t),
1322 KM_SLEEP);
1323 space_map_create(msp->ms_defermap[t], sm->sm_start,
1324 sm->sm_size, sm->sm_shift, sm->sm_lock);
1325 }
1326
1327 freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
1328 defer_map = &msp->ms_defermap[txg % TXG_DEFER_SIZE];
1329
1330 vdev_space_update(vd, 0, 0, sm->sm_size);
1331 }
1332
1333 alloc_delta = smosync->smo_alloc - smo->smo_alloc;
1334 defer_delta = (*freed_map)->sm_space - (*defer_map)->sm_space;
1335
1336 vdev_space_update(vd, alloc_delta + defer_delta, defer_delta, 0);
1337
1338 ASSERT(msp->ms_allocmap[txg & TXG_MASK]->sm_space == 0);
1339 ASSERT(msp->ms_freemap[txg & TXG_MASK]->sm_space == 0);
1340
1341 /*
1342 * If there's a space_map_load() in progress, wait for it to complete
1343 * so that we have a consistent view of the in-core space map.
1344 */
1345 space_map_load_wait(sm);
1346
1347 /*
1348 * Move the frees from the defer_map to this map (if it's loaded).
1349 * Swap the freed_map and the defer_map -- this is safe to do
1350 * because we've just emptied out the defer_map.
1351 */
1352 space_map_vacate(*defer_map, sm->sm_loaded ? space_map_free : NULL, sm);
1353 ASSERT0((*defer_map)->sm_space);
1354 ASSERT0(avl_numnodes(&(*defer_map)->sm_root));
1355 space_map_swap(freed_map, defer_map);
1356
1357 *smo = *smosync;
1358
1359 msp->ms_deferspace += defer_delta;
1360 ASSERT3S(msp->ms_deferspace, >=, 0);
1361 ASSERT3S(msp->ms_deferspace, <=, sm->sm_size);
1362 if (msp->ms_deferspace != 0) {
1363 /*
1364 * Keep syncing this metaslab until all deferred frees
1365 * are back in circulation.
1366 */
1367 vdev_dirty(vd, VDD_METASLAB, msp, txg + 1);
1368 }
1369
1370 /*
1371 * If the map is loaded but no longer active, evict it as soon as all
1372 * future allocations have synced. (If we unloaded it now and then
1373 * loaded a moment later, the map wouldn't reflect those allocations.)
1374 */
1375 if (sm->sm_loaded && (msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
1376 int evictable = 1;
1377
1378 for (int t = 1; t < TXG_CONCURRENT_STATES; t++)
1379 if (msp->ms_allocmap[(txg + t) & TXG_MASK]->sm_space)
1380 evictable = 0;
1381
1382 if (evictable && !metaslab_debug)
1383 space_map_unload(sm);
1384 }
1385
1386 metaslab_group_sort(mg, msp, metaslab_weight(msp));
1387
1388 mutex_exit(&msp->ms_lock);
1389 }
1390
1391 void
1392 metaslab_sync_reassess(metaslab_group_t *mg)
1393 {
1394 vdev_t *vd = mg->mg_vd;
1395 int64_t failures = mg->mg_alloc_failures;
1396
1397 metaslab_group_alloc_update(mg);
1398
1399 /*
1400 * Re-evaluate all metaslabs which have lower offsets than the
1401 * bonus area.
1402 */
1403 for (int m = 0; m < vd->vdev_ms_count; m++) {
1404 metaslab_t *msp = vd->vdev_ms[m];
1405
1406 if (msp->ms_map->sm_start > mg->mg_bonus_area)
1407 break;
1408
1409 mutex_enter(&msp->ms_lock);
1410 metaslab_group_sort(mg, msp, metaslab_weight(msp));
1411 mutex_exit(&msp->ms_lock);
1412 }
1413
1414 atomic_add_64(&mg->mg_alloc_failures, -failures);
1415
1416 /*
1417 * Prefetch the next potential metaslabs
1418 */
1419 metaslab_prefetch(mg);
1420 }
1421
1422 static uint64_t
1423 metaslab_distance(metaslab_t *msp, dva_t *dva)
1424 {
1425 uint64_t ms_shift = msp->ms_group->mg_vd->vdev_ms_shift;
1426 uint64_t offset = DVA_GET_OFFSET(dva) >> ms_shift;
1427 uint64_t start = msp->ms_map->sm_start >> ms_shift;
1428
1429 if (msp->ms_group->mg_vd->vdev_id != DVA_GET_VDEV(dva))
1430 return (1ULL << 63);
1431
1432 if (offset < start)
1433 return ((start - offset) << ms_shift);
1434 if (offset > start)
1435 return ((offset - start) << ms_shift);
1436 return (0);
1437 }
1438
1439 static uint64_t
1440 metaslab_group_alloc(metaslab_group_t *mg, uint64_t psize, uint64_t asize,
1441 uint64_t txg, uint64_t min_distance, dva_t *dva, int d, int flags)
1442 {
1443 spa_t *spa = mg->mg_vd->vdev_spa;
1444 metaslab_t *msp = NULL;
1445 uint64_t offset = -1ULL;
1446 avl_tree_t *t = &mg->mg_metaslab_tree;
1447 uint64_t activation_weight;
1448 uint64_t target_distance;
1449 int i;
1450
1451 activation_weight = METASLAB_WEIGHT_PRIMARY;
1452 for (i = 0; i < d; i++) {
1453 if (DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) {
1454 activation_weight = METASLAB_WEIGHT_SECONDARY;
1455 break;
1456 }
1457 }
1458
1459 for (;;) {
1460 boolean_t was_active;
1461
1462 mutex_enter(&mg->mg_lock);
1463 for (msp = avl_first(t); msp; msp = AVL_NEXT(t, msp)) {
1464 if (msp->ms_weight < asize) {
1465 spa_dbgmsg(spa, "%s: failed to meet weight "
1466 "requirement: vdev %llu, txg %llu, mg %p, "
1467 "msp %p, psize %llu, asize %llu, "
1468 "failures %llu, weight %llu",
1469 spa_name(spa), mg->mg_vd->vdev_id, txg,
1470 mg, msp, psize, asize,
1471 mg->mg_alloc_failures, msp->ms_weight);
1472 mutex_exit(&mg->mg_lock);
1473 return (-1ULL);
1474 }
1475
1476 /*
1477 * If the selected metaslab is condensing, skip it.
1478 */
1479 if (msp->ms_map->sm_condensing)
1480 continue;
1481
1482 was_active = msp->ms_weight & METASLAB_ACTIVE_MASK;
1483 if (activation_weight == METASLAB_WEIGHT_PRIMARY)
1484 break;
1485
1486 target_distance = min_distance +
1487 (msp->ms_smo.smo_alloc ? 0 : min_distance >> 1);
1488
1489 for (i = 0; i < d; i++)
1490 if (metaslab_distance(msp, &dva[i]) <
1491 target_distance)
1492 break;
1493 if (i == d)
1494 break;
1495 }
1496 mutex_exit(&mg->mg_lock);
1497 if (msp == NULL)
1498 return (-1ULL);
1499
1500 mutex_enter(&msp->ms_lock);
1501
1502 /*
1503 * If we've already reached the allowable number of failed
1504 * allocation attempts on this metaslab group then we
1505 * consider skipping it. We skip it only if we're allowed
1506 * to "fast" gang, the physical size is larger than
1507 * a gang block, and we're attempting to allocate from
1508 * the primary metaslab.
1509 */
1510 if (mg->mg_alloc_failures > zfs_mg_alloc_failures &&
1511 CAN_FASTGANG(flags) && psize > SPA_GANGBLOCKSIZE &&
1512 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1513 spa_dbgmsg(spa, "%s: skipping metaslab group: "
1514 "vdev %llu, txg %llu, mg %p, psize %llu, "
1515 "asize %llu, failures %llu", spa_name(spa),
1516 mg->mg_vd->vdev_id, txg, mg, psize, asize,
1517 mg->mg_alloc_failures);
1518 mutex_exit(&msp->ms_lock);
1519 return (-1ULL);
1520 }
1521
1522 /*
1523 * Ensure that the metaslab we have selected is still
1524 * capable of handling our request. It's possible that
1525 * another thread may have changed the weight while we
1526 * were blocked on the metaslab lock.
1527 */
1528 if (msp->ms_weight < asize || (was_active &&
1529 !(msp->ms_weight & METASLAB_ACTIVE_MASK) &&
1530 activation_weight == METASLAB_WEIGHT_PRIMARY)) {
1531 mutex_exit(&msp->ms_lock);
1532 continue;
1533 }
1534
1535 if ((msp->ms_weight & METASLAB_WEIGHT_SECONDARY) &&
1536 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1537 metaslab_passivate(msp,
1538 msp->ms_weight & ~METASLAB_ACTIVE_MASK);
1539 mutex_exit(&msp->ms_lock);
1540 continue;
1541 }
1542
1543 if (metaslab_activate(msp, activation_weight) != 0) {
1544 mutex_exit(&msp->ms_lock);
1545 continue;
1546 }
1547
1548 /*
1549 * If this metaslab is currently condensing then pick again as
1550 * we can't manipulate this metaslab until it's committed
1551 * to disk.
1552 */
1553 if (msp->ms_map->sm_condensing) {
1554 mutex_exit(&msp->ms_lock);
1555 continue;
1556 }
1557
1558 if ((offset = space_map_alloc(msp->ms_map, asize)) != -1ULL)
1559 break;
1560
1561 atomic_inc_64(&mg->mg_alloc_failures);
1562
1563 metaslab_passivate(msp, space_map_maxsize(msp->ms_map));
1564
1565 mutex_exit(&msp->ms_lock);
1566 }
1567
1568 if (msp->ms_allocmap[txg & TXG_MASK]->sm_space == 0)
1569 vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg);
1570
1571 space_map_add(msp->ms_allocmap[txg & TXG_MASK], offset, asize);
1572
1573 mutex_exit(&msp->ms_lock);
1574
1575 return (offset);
1576 }
1577
1578 /*
1579 * Allocate a block for the specified i/o.
1580 */
1581 static int
1582 metaslab_alloc_dva(spa_t *spa, metaslab_class_t *mc, uint64_t psize,
1583 dva_t *dva, int d, dva_t *hintdva, uint64_t txg, int flags)
1584 {
1585 metaslab_group_t *mg, *rotor;
1586 vdev_t *vd;
1587 int dshift = 3;
1588 int all_zero;
1589 int zio_lock = B_FALSE;
1590 boolean_t allocatable;
1591 uint64_t offset = -1ULL;
1592 uint64_t asize;
1593 uint64_t distance;
1594
1595 ASSERT(!DVA_IS_VALID(&dva[d]));
1596
1597 /*
1598 * For testing, make some blocks above a certain size be gang blocks.
1599 */
1600 if (psize >= metaslab_gang_bang && (ddi_get_lbolt() & 3) == 0)
1601 return (SET_ERROR(ENOSPC));
1602
1603 /*
1604 * Start at the rotor and loop through all mgs until we find something.
1605 * Note that there's no locking on mc_rotor or mc_aliquot because
1606 * nothing actually breaks if we miss a few updates -- we just won't
1607 * allocate quite as evenly. It all balances out over time.
1608 *
1609 * If we are doing ditto or log blocks, try to spread them across
1610 * consecutive vdevs. If we're forced to reuse a vdev before we've
1611 * allocated all of our ditto blocks, then try and spread them out on
1612 * that vdev as much as possible. If it turns out to not be possible,
1613 * gradually lower our standards until anything becomes acceptable.
1614 * Also, allocating on consecutive vdevs (as opposed to random vdevs)
1615 * gives us hope of containing our fault domains to something we're
1616 * able to reason about. Otherwise, any two top-level vdev failures
1617 * will guarantee the loss of data. With consecutive allocation,
1618 * only two adjacent top-level vdev failures will result in data loss.
1619 *
1620 * If we are doing gang blocks (hintdva is non-NULL), try to keep
1621 * ourselves on the same vdev as our gang block header. That
1622 * way, we can hope for locality in vdev_cache, plus it makes our
1623 * fault domains something tractable.
1624 */
1625 if (hintdva) {
1626 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&hintdva[d]));
1627
1628 /*
1629 * It's possible the vdev we're using as the hint no
1630 * longer exists (i.e. removed). Consult the rotor when
1631 * all else fails.
1632 */
1633 if (vd != NULL) {
1634 mg = vd->vdev_mg;
1635
1636 if (flags & METASLAB_HINTBP_AVOID &&
1637 mg->mg_next != NULL)
1638 mg = mg->mg_next;
1639 } else {
1640 mg = mc->mc_rotor;
1641 }
1642 } else if (d != 0) {
1643 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[d - 1]));
1644 mg = vd->vdev_mg->mg_next;
1645 } else {
1646 mg = mc->mc_rotor;
1647 }
1648
1649 /*
1650 * If the hint put us into the wrong metaslab class, or into a
1651 * metaslab group that has been passivated, just follow the rotor.
1652 */
1653 if (mg->mg_class != mc || mg->mg_activation_count <= 0)
1654 mg = mc->mc_rotor;
1655
1656 rotor = mg;
1657 top:
1658 all_zero = B_TRUE;
1659 do {
1660 ASSERT(mg->mg_activation_count == 1);
1661
1662 vd = mg->mg_vd;
1663
1664 /*
1665 * Don't allocate from faulted devices.
1666 */
1667 if (zio_lock) {
1668 spa_config_enter(spa, SCL_ZIO, FTAG, RW_READER);
1669 allocatable = vdev_allocatable(vd);
1670 spa_config_exit(spa, SCL_ZIO, FTAG);
1671 } else {
1672 allocatable = vdev_allocatable(vd);
1673 }
1674
1675 /*
1676 * Determine if the selected metaslab group is eligible
1677 * for allocations. If we're ganging or have requested
1678 * an allocation for the smallest gang block size
1679 * then we don't want to avoid allocating to the this
1680 * metaslab group. If we're in this condition we should
1681 * try to allocate from any device possible so that we
1682 * don't inadvertently return ENOSPC and suspend the pool
1683 * even though space is still available.
1684 */
1685 if (allocatable && CAN_FASTGANG(flags) &&
1686 psize > SPA_GANGBLOCKSIZE)
1687 allocatable = metaslab_group_allocatable(mg);
1688
1689 if (!allocatable)
1690 goto next;
1691
1692 /*
1693 * Avoid writing single-copy data to a failing vdev
1694 * unless the user instructs us that it is okay.
1695 */
1696 if ((vd->vdev_stat.vs_write_errors > 0 ||
1697 vd->vdev_state < VDEV_STATE_HEALTHY) &&
1698 d == 0 && dshift == 3 &&
1699 !(zfs_write_to_degraded && vd->vdev_state ==
1700 VDEV_STATE_DEGRADED)) {
1701 all_zero = B_FALSE;
1702 goto next;
1703 }
1704
1705 ASSERT(mg->mg_class == mc);
1706
1707 distance = vd->vdev_asize >> dshift;
1708 if (distance <= (1ULL << vd->vdev_ms_shift))
1709 distance = 0;
1710 else
1711 all_zero = B_FALSE;
1712
1713 asize = vdev_psize_to_asize(vd, psize);
1714 ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0);
1715
1716 offset = metaslab_group_alloc(mg, psize, asize, txg, distance,
1717 dva, d, flags);
1718 if (offset != -1ULL) {
1719 /*
1720 * If we've just selected this metaslab group,
1721 * figure out whether the corresponding vdev is
1722 * over- or under-used relative to the pool,
1723 * and set an allocation bias to even it out.
1724 */
1725 if (mc->mc_aliquot == 0) {
1726 vdev_stat_t *vs = &vd->vdev_stat;
1727 int64_t vu, cu;
1728
1729 vu = (vs->vs_alloc * 100) / (vs->vs_space + 1);
1730 cu = (mc->mc_alloc * 100) / (mc->mc_space + 1);
1731
1732 /*
1733 * Calculate how much more or less we should
1734 * try to allocate from this device during
1735 * this iteration around the rotor.
1736 * For example, if a device is 80% full
1737 * and the pool is 20% full then we should
1738 * reduce allocations by 60% on this device.
1739 *
1740 * mg_bias = (20 - 80) * 512K / 100 = -307K
1741 *
1742 * This reduces allocations by 307K for this
1743 * iteration.
1744 */
1745 mg->mg_bias = ((cu - vu) *
1746 (int64_t)mg->mg_aliquot) / 100;
1747 }
1748
1749 if (atomic_add_64_nv(&mc->mc_aliquot, asize) >=
1750 mg->mg_aliquot + mg->mg_bias) {
1751 mc->mc_rotor = mg->mg_next;
1752 mc->mc_aliquot = 0;
1753 }
1754
1755 DVA_SET_VDEV(&dva[d], vd->vdev_id);
1756 DVA_SET_OFFSET(&dva[d], offset);
1757 DVA_SET_GANG(&dva[d], !!(flags & METASLAB_GANG_HEADER));
1758 DVA_SET_ASIZE(&dva[d], asize);
1759
1760 return (0);
1761 }
1762 next:
1763 mc->mc_rotor = mg->mg_next;
1764 mc->mc_aliquot = 0;
1765 } while ((mg = mg->mg_next) != rotor);
1766
1767 if (!all_zero) {
1768 dshift++;
1769 ASSERT(dshift < 64);
1770 goto top;
1771 }
1772
1773 if (!allocatable && !zio_lock) {
1774 dshift = 3;
1775 zio_lock = B_TRUE;
1776 goto top;
1777 }
1778
1779 bzero(&dva[d], sizeof (dva_t));
1780
1781 return (SET_ERROR(ENOSPC));
1782 }
1783
1784 /*
1785 * Free the block represented by DVA in the context of the specified
1786 * transaction group.
1787 */
1788 static void
1789 metaslab_free_dva(spa_t *spa, const dva_t *dva, uint64_t txg, boolean_t now)
1790 {
1791 uint64_t vdev = DVA_GET_VDEV(dva);
1792 uint64_t offset = DVA_GET_OFFSET(dva);
1793 uint64_t size = DVA_GET_ASIZE(dva);
1794 vdev_t *vd;
1795 metaslab_t *msp;
1796
1797 ASSERT(DVA_IS_VALID(dva));
1798
1799 if (txg > spa_freeze_txg(spa))
1800 return;
1801
1802 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
1803 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count) {
1804 cmn_err(CE_WARN, "metaslab_free_dva(): bad DVA %llu:%llu",
1805 (u_longlong_t)vdev, (u_longlong_t)offset);
1806 ASSERT(0);
1807 return;
1808 }
1809
1810 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
1811
1812 if (DVA_GET_GANG(dva))
1813 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
1814
1815 mutex_enter(&msp->ms_lock);
1816
1817 if (now) {
1818 space_map_remove(msp->ms_allocmap[txg & TXG_MASK],
1819 offset, size);
1820 space_map_free(msp->ms_map, offset, size);
1821 } else {
1822 if (msp->ms_freemap[txg & TXG_MASK]->sm_space == 0)
1823 vdev_dirty(vd, VDD_METASLAB, msp, txg);
1824 space_map_add(msp->ms_freemap[txg & TXG_MASK], offset, size);
1825 }
1826
1827 mutex_exit(&msp->ms_lock);
1828 }
1829
1830 /*
1831 * Intent log support: upon opening the pool after a crash, notify the SPA
1832 * of blocks that the intent log has allocated for immediate write, but
1833 * which are still considered free by the SPA because the last transaction
1834 * group didn't commit yet.
1835 */
1836 static int
1837 metaslab_claim_dva(spa_t *spa, const dva_t *dva, uint64_t txg)
1838 {
1839 uint64_t vdev = DVA_GET_VDEV(dva);
1840 uint64_t offset = DVA_GET_OFFSET(dva);
1841 uint64_t size = DVA_GET_ASIZE(dva);
1842 vdev_t *vd;
1843 metaslab_t *msp;
1844 int error = 0;
1845
1846 ASSERT(DVA_IS_VALID(dva));
1847
1848 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
1849 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count)
1850 return (SET_ERROR(ENXIO));
1851
1852 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
1853
1854 if (DVA_GET_GANG(dva))
1855 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
1856
1857 mutex_enter(&msp->ms_lock);
1858
1859 if ((txg != 0 && spa_writeable(spa)) || !msp->ms_map->sm_loaded)
1860 error = metaslab_activate(msp, METASLAB_WEIGHT_SECONDARY);
1861
1862 if (error == 0 && !space_map_contains(msp->ms_map, offset, size))
1863 error = SET_ERROR(ENOENT);
1864
1865 if (error || txg == 0) { /* txg == 0 indicates dry run */
1866 mutex_exit(&msp->ms_lock);
1867 return (error);
1868 }
1869
1870 space_map_claim(msp->ms_map, offset, size);
1871
1872 if (spa_writeable(spa)) { /* don't dirty if we're zdb(1M) */
1873 if (msp->ms_allocmap[txg & TXG_MASK]->sm_space == 0)
1874 vdev_dirty(vd, VDD_METASLAB, msp, txg);
1875 space_map_add(msp->ms_allocmap[txg & TXG_MASK], offset, size);
1876 }
1877
1878 mutex_exit(&msp->ms_lock);
1879
1880 return (0);
1881 }
1882
1883 int
1884 metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp,
1885 int ndvas, uint64_t txg, blkptr_t *hintbp, int flags)
1886 {
1887 dva_t *dva = bp->blk_dva;
1888 dva_t *hintdva = hintbp->blk_dva;
1889 int error = 0;
1890
1891 ASSERT(bp->blk_birth == 0);
1892 ASSERT(BP_PHYSICAL_BIRTH(bp) == 0);
1893
1894 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
1895
1896 if (mc->mc_rotor == NULL) { /* no vdevs in this class */
1897 spa_config_exit(spa, SCL_ALLOC, FTAG);
1898 return (SET_ERROR(ENOSPC));
1899 }
1900
1901 ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa));
1902 ASSERT(BP_GET_NDVAS(bp) == 0);
1903 ASSERT(hintbp == NULL || ndvas <= BP_GET_NDVAS(hintbp));
1904
1905 for (int d = 0; d < ndvas; d++) {
1906 error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva,
1907 txg, flags);
1908 if (error) {
1909 for (d--; d >= 0; d--) {
1910 metaslab_free_dva(spa, &dva[d], txg, B_TRUE);
1911 bzero(&dva[d], sizeof (dva_t));
1912 }
1913 spa_config_exit(spa, SCL_ALLOC, FTAG);
1914 return (error);
1915 }
1916 }
1917 ASSERT(error == 0);
1918 ASSERT(BP_GET_NDVAS(bp) == ndvas);
1919
1920 spa_config_exit(spa, SCL_ALLOC, FTAG);
1921
1922 BP_SET_BIRTH(bp, txg, txg);
1923
1924 return (0);
1925 }
1926
1927 void
1928 metaslab_free(spa_t *spa, const blkptr_t *bp, uint64_t txg, boolean_t now)
1929 {
1930 const dva_t *dva = bp->blk_dva;
1931 int ndvas = BP_GET_NDVAS(bp);
1932
1933 ASSERT(!BP_IS_HOLE(bp));
1934 ASSERT(!now || bp->blk_birth >= spa_syncing_txg(spa));
1935
1936 spa_config_enter(spa, SCL_FREE, FTAG, RW_READER);
1937
1938 for (int d = 0; d < ndvas; d++)
1939 metaslab_free_dva(spa, &dva[d], txg, now);
1940
1941 spa_config_exit(spa, SCL_FREE, FTAG);
1942 }
1943
1944 int
1945 metaslab_claim(spa_t *spa, const blkptr_t *bp, uint64_t txg)
1946 {
1947 const dva_t *dva = bp->blk_dva;
1948 int ndvas = BP_GET_NDVAS(bp);
1949 int error = 0;
1950
1951 ASSERT(!BP_IS_HOLE(bp));
1952
1953 if (txg != 0) {
1954 /*
1955 * First do a dry run to make sure all DVAs are claimable,
1956 * so we don't have to unwind from partial failures below.
1957 */
1958 if ((error = metaslab_claim(spa, bp, 0)) != 0)
1959 return (error);
1960 }
1961
1962 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
1963
1964 for (int d = 0; d < ndvas; d++)
1965 if ((error = metaslab_claim_dva(spa, &dva[d], txg)) != 0)
1966 break;
1967
1968 spa_config_exit(spa, SCL_ALLOC, FTAG);
1969
1970 ASSERT(error == 0 || txg == 0);
1971
1972 return (error);
1973 }
1974
1975 static void
1976 checkmap(space_map_t *sm, uint64_t off, uint64_t size)
1977 {
1978 space_seg_t *ss;
1979 avl_index_t where;
1980
1981 mutex_enter(sm->sm_lock);
1982 ss = space_map_find(sm, off, size, &where);
1983 if (ss != NULL)
1984 panic("freeing free block; ss=%p", (void *)ss);
1985 mutex_exit(sm->sm_lock);
1986 }
1987
1988 void
1989 metaslab_check_free(spa_t *spa, const blkptr_t *bp)
1990 {
1991 if ((zfs_flags & ZFS_DEBUG_ZIO_FREE) == 0)
1992 return;
1993
1994 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1995 for (int i = 0; i < BP_GET_NDVAS(bp); i++) {
1996 uint64_t vdid = DVA_GET_VDEV(&bp->blk_dva[i]);
1997 vdev_t *vd = vdev_lookup_top(spa, vdid);
1998 uint64_t off = DVA_GET_OFFSET(&bp->blk_dva[i]);
1999 uint64_t size = DVA_GET_ASIZE(&bp->blk_dva[i]);
2000 metaslab_t *ms = vd->vdev_ms[off >> vd->vdev_ms_shift];
2001
2002 if (ms->ms_map->sm_loaded)
2003 checkmap(ms->ms_map, off, size);
2004
2005 for (int j = 0; j < TXG_SIZE; j++)
2006 checkmap(ms->ms_freemap[j], off, size);
2007 for (int j = 0; j < TXG_DEFER_SIZE; j++)
2008 checkmap(ms->ms_defermap[j], off, size);
2009 }
2010 spa_config_exit(spa, SCL_VDEV, FTAG);
2011 }