100 * ==========================================================================
101 * Metaslab classes
102 * ==========================================================================
103 */
104metaslab_class_t *
105metaslab_class_create(spa_t *spa, space_map_ops_t *ops)
106{
107 metaslab_class_t *mc;
108
109 mc = kmem_zalloc(sizeof (metaslab_class_t), KM_SLEEP);
110
111 mc->mc_spa = spa;
112 mc->mc_rotor = NULL;
113 mc->mc_ops = ops;
114
115 return (mc);
116}
117
118void
119metaslab_class_destroy(metaslab_class_t *mc)
120{
121 ASSERT(mc->mc_rotor == NULL);
122 ASSERT(mc->mc_alloc == 0);
123 ASSERT(mc->mc_deferred == 0);
124 ASSERT(mc->mc_space == 0);
125 ASSERT(mc->mc_dspace == 0);
126
127 kmem_free(mc, sizeof (metaslab_class_t));
128}
129
130int
131metaslab_class_validate(metaslab_class_t *mc)
132{
133 metaslab_group_t *mg;
134 vdev_t *vd;
135
136 /*
137 * Must hold one of the spa_config locks.
138 */
139 ASSERT(spa_config_held(mc->mc_spa, SCL_ALL, RW_READER) ||
140 spa_config_held(mc->mc_spa, SCL_ALL, RW_WRITER));
141
142 if ((mg = mc->mc_rotor) == NULL)
143 return (0);
144
145 do {
146 vd = mg->mg_vd;
147 ASSERT(vd->vdev_mg != NULL);
148 ASSERT3P(vd->vdev_top, ==, vd);
149 ASSERT3P(mg->mg_class, ==, mc);
150 ASSERT3P(vd->vdev_ops, !=, &vdev_hole_ops);
151 } while ((mg = mg->mg_next) != mc->mc_rotor);
152
153 return (0);
154}
155
156void
157metaslab_class_space_update(metaslab_class_t *mc, int64_t alloc_delta,
158 int64_t defer_delta, int64_t space_delta, int64_t dspace_delta)
159{
160 atomic_add_64(&mc->mc_alloc, alloc_delta);
161 atomic_add_64(&mc->mc_deferred, defer_delta);
162 atomic_add_64(&mc->mc_space, space_delta);
163 atomic_add_64(&mc->mc_dspace, dspace_delta);
164}
165
166uint64_t
167metaslab_class_get_alloc(metaslab_class_t *mc)
168{
169 return (mc->mc_alloc);
170}
171
172uint64_t
173metaslab_class_get_deferred(metaslab_class_t *mc)
174{
175 return (mc->mc_deferred);
176}
177
178uint64_t
179metaslab_class_get_space(metaslab_class_t *mc)
180{
181 return (mc->mc_space);
182}
183
184uint64_t
185metaslab_class_get_dspace(metaslab_class_t *mc)
186{
187 return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space);
188}
189
190/*
191 * ==========================================================================
192 * Metaslab groups
193 * ==========================================================================
194 */
195static int
196metaslab_compare(const void *x1, const void *x2)
197{
198 const metaslab_t *m1 = x1;
199 const metaslab_t *m2 = x2;
200
201 if (m1->ms_weight < m2->ms_weight)
202 return (1);
203 if (m1->ms_weight > m2->ms_weight)
204 return (-1);
205
206 /*
207 * If the weights are identical, use the offset to force uniqueness.
208 */
209 if (m1->ms_map.sm_start < m2->ms_map.sm_start)
210 return (-1);
211 if (m1->ms_map.sm_start > m2->ms_map.sm_start)
212 return (1);
213
214 ASSERT3P(m1, ==, m2);
215
216 return (0);
217}
218
219metaslab_group_t *
220metaslab_group_create(metaslab_class_t *mc, vdev_t *vd)
221{
222 metaslab_group_t *mg;
223
224 mg = kmem_zalloc(sizeof (metaslab_group_t), KM_SLEEP);
225 mutex_init(&mg->mg_lock, NULL, MUTEX_DEFAULT, NULL);
226 avl_create(&mg->mg_metaslab_tree, metaslab_compare,
227 sizeof (metaslab_t), offsetof(struct metaslab, ms_group_node));
228 mg->mg_vd = vd;
229 mg->mg_class = mc;
230 mg->mg_activation_count = 0;
231
232 return (mg);
233}
234
235void
236metaslab_group_destroy(metaslab_group_t *mg)
237{
238 ASSERT(mg->mg_prev == NULL);
239 ASSERT(mg->mg_next == NULL);
240 /*
241 * We may have gone below zero with the activation count
242 * either because we never activated in the first place or
243 * because we're done, and possibly removing the vdev.
244 */
245 ASSERT(mg->mg_activation_count <= 0);
246
247 avl_destroy(&mg->mg_metaslab_tree);
248 mutex_destroy(&mg->mg_lock);
249 kmem_free(mg, sizeof (metaslab_group_t));
250}
251
252void
253metaslab_group_activate(metaslab_group_t *mg)
254{
255 metaslab_class_t *mc = mg->mg_class;
256 metaslab_group_t *mgprev, *mgnext;
257
258 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
259
260 ASSERT(mc->mc_rotor != mg);
261 ASSERT(mg->mg_prev == NULL);
262 ASSERT(mg->mg_next == NULL);
263 ASSERT(mg->mg_activation_count <= 0);
264
265 if (++mg->mg_activation_count <= 0)
266 return;
267
268 mg->mg_aliquot = metaslab_aliquot * MAX(1, mg->mg_vd->vdev_children);
269
270 if ((mgprev = mc->mc_rotor) == NULL) {
271 mg->mg_prev = mg;
272 mg->mg_next = mg;
273 } else {
274 mgnext = mgprev->mg_next;
275 mg->mg_prev = mgprev;
276 mg->mg_next = mgnext;
277 mgprev->mg_next = mg;
278 mgnext->mg_prev = mg;
279 }
280 mc->mc_rotor = mg;
281}
282
283void
284metaslab_group_passivate(metaslab_group_t *mg)
285{
286 metaslab_class_t *mc = mg->mg_class;
287 metaslab_group_t *mgprev, *mgnext;
288
289 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
290
291 if (--mg->mg_activation_count != 0) {
292 ASSERT(mc->mc_rotor != mg);
293 ASSERT(mg->mg_prev == NULL);
294 ASSERT(mg->mg_next == NULL);
295 ASSERT(mg->mg_activation_count < 0);
296 return;
297 }
298
299 mgprev = mg->mg_prev;
300 mgnext = mg->mg_next;
301
302 if (mg == mgnext) {
303 mc->mc_rotor = NULL;
304 } else {
305 mc->mc_rotor = mgnext;
306 mgprev->mg_next = mgnext;
307 mgnext->mg_prev = mgprev;
308 }
309
310 mg->mg_prev = NULL;
311 mg->mg_next = NULL;
312}
313
314static void
315metaslab_group_add(metaslab_group_t *mg, metaslab_t *msp)
316{
317 mutex_enter(&mg->mg_lock);
318 ASSERT(msp->ms_group == NULL);
319 msp->ms_group = mg;
320 msp->ms_weight = 0;
321 avl_add(&mg->mg_metaslab_tree, msp);
322 mutex_exit(&mg->mg_lock);
323}
324
325static void
326metaslab_group_remove(metaslab_group_t *mg, metaslab_t *msp)
327{
328 mutex_enter(&mg->mg_lock);
329 ASSERT(msp->ms_group == mg);
330 avl_remove(&mg->mg_metaslab_tree, msp);
331 msp->ms_group = NULL;
332 mutex_exit(&mg->mg_lock);
333}
334
335static void
336metaslab_group_sort(metaslab_group_t *mg, metaslab_t *msp, uint64_t weight)
337{
338 /*
339 * Although in principle the weight can be any value, in
340 * practice we do not use values in the range [1, 510].
341 */
342 ASSERT(weight >= SPA_MINBLOCKSIZE-1 || weight == 0);
343 ASSERT(MUTEX_HELD(&msp->ms_lock));
344
345 mutex_enter(&mg->mg_lock);
346 ASSERT(msp->ms_group == mg);
347 avl_remove(&mg->mg_metaslab_tree, msp);
348 msp->ms_weight = weight;
349 avl_add(&mg->mg_metaslab_tree, msp);
350 mutex_exit(&mg->mg_lock);
351}
352
353/*
354 * ==========================================================================
355 * Common allocator routines
356 * ==========================================================================
357 */
358static int
359metaslab_segsize_compare(const void *x1, const void *x2)
360{
361 const space_seg_t *s1 = x1;
362 const space_seg_t *s2 = x2;
363 uint64_t ss_size1 = s1->ss_end - s1->ss_start;
364 uint64_t ss_size2 = s2->ss_end - s2->ss_start;
365
366 if (ss_size1 < ss_size2)
367 return (-1);
368 if (ss_size1 > ss_size2)
369 return (1);
370
371 if (s1->ss_start < s2->ss_start)
372 return (-1);
373 if (s1->ss_start > s2->ss_start)
374 return (1);
375
376 return (0);
377}
378
379/*
380 * This is a helper function that can be used by the allocator to find
381 * a suitable block to allocate. This will search the specified AVL
382 * tree looking for a block that matches the specified criteria.
383 */
384static uint64_t
385metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size,
386 uint64_t align)
387{
388 space_seg_t *ss, ssearch;
389 avl_index_t where;
390
391 ssearch.ss_start = *cursor;
392 ssearch.ss_end = *cursor + size;
393
394 ss = avl_find(t, &ssearch, &where);
395 if (ss == NULL)
396 ss = avl_nearest(t, where, AVL_AFTER);
397
398 while (ss != NULL) {
399 uint64_t offset = P2ROUNDUP(ss->ss_start, align);
400
401 if (offset + size <= ss->ss_end) {
402 *cursor = offset + size;
403 return (offset);
404 }
405 ss = AVL_NEXT(t, ss);
406 }
407
408 /*
409 * If we know we've searched the whole map (*cursor == 0), give up.
410 * Otherwise, reset the cursor to the beginning and try again.
411 */
412 if (*cursor == 0)
413 return (-1ULL);
414
415 *cursor = 0;
416 return (metaslab_block_picker(t, cursor, size, align));
417}
418
419static void
420metaslab_pp_load(space_map_t *sm)
421{
422 space_seg_t *ss;
423
424 ASSERT(sm->sm_ppd == NULL);
425 sm->sm_ppd = kmem_zalloc(64 * sizeof (uint64_t), KM_SLEEP);
426
427 sm->sm_pp_root = kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
428 avl_create(sm->sm_pp_root, metaslab_segsize_compare,
429 sizeof (space_seg_t), offsetof(struct space_seg, ss_pp_node));
430
431 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
432 avl_add(sm->sm_pp_root, ss);
433}
434
435static void
436metaslab_pp_unload(space_map_t *sm)
437{
438 void *cookie = NULL;
439
440 kmem_free(sm->sm_ppd, 64 * sizeof (uint64_t));
441 sm->sm_ppd = NULL;
442
443 while (avl_destroy_nodes(sm->sm_pp_root, &cookie) != NULL) {
444 /* tear down the tree */
445 }
446
447 avl_destroy(sm->sm_pp_root);
448 kmem_free(sm->sm_pp_root, sizeof (avl_tree_t));
449 sm->sm_pp_root = NULL;
450}
451
452/* ARGSUSED */
453static void
454metaslab_pp_claim(space_map_t *sm, uint64_t start, uint64_t size)
455{
456 /* No need to update cursor */
457}
458
459/* ARGSUSED */
460static void
461metaslab_pp_free(space_map_t *sm, uint64_t start, uint64_t size)
462{
463 /* No need to update cursor */
464}
465
466/*
467 * Return the maximum contiguous segment within the metaslab.
468 */
469uint64_t
470metaslab_pp_maxsize(space_map_t *sm)
471{
472 avl_tree_t *t = sm->sm_pp_root;
473 space_seg_t *ss;
474
475 if (t == NULL || (ss = avl_last(t)) == NULL)
476 return (0ULL);
477
478 return (ss->ss_end - ss->ss_start);
479}
480
481/*
482 * ==========================================================================
483 * The first-fit block allocator
484 * ==========================================================================
485 */
486static uint64_t
487metaslab_ff_alloc(space_map_t *sm, uint64_t size)
488{
489 avl_tree_t *t = &sm->sm_root;
490 uint64_t align = size & -size;
491 uint64_t *cursor = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
492
493 return (metaslab_block_picker(t, cursor, size, align));
494}
495
496/* ARGSUSED */
497boolean_t
498metaslab_ff_fragmented(space_map_t *sm)
499{
500 return (B_TRUE);
501}
502
503static space_map_ops_t metaslab_ff_ops = {
504 metaslab_pp_load,
505 metaslab_pp_unload,
506 metaslab_ff_alloc,
507 metaslab_pp_claim,
508 metaslab_pp_free,
509 metaslab_pp_maxsize,
510 metaslab_ff_fragmented
511};
512
513/*
514 * ==========================================================================
515 * Dynamic block allocator -
516 * Uses the first fit allocation scheme until space get low and then
517 * adjusts to a best fit allocation method. Uses metaslab_df_alloc_threshold
518 * and metaslab_df_free_pct to determine when to switch the allocation scheme.
519 * ==========================================================================
520 */
521static uint64_t
522metaslab_df_alloc(space_map_t *sm, uint64_t size)
523{
524 avl_tree_t *t = &sm->sm_root;
525 uint64_t align = size & -size;
526 uint64_t *cursor = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
527 uint64_t max_size = metaslab_pp_maxsize(sm);
528 int free_pct = sm->sm_space * 100 / sm->sm_size;
529
530 ASSERT(MUTEX_HELD(sm->sm_lock));
531 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
532
533 if (max_size < size)
534 return (-1ULL);
535
536 /*
537 * If we're running low on space switch to using the size
538 * sorted AVL tree (best-fit).
539 */
540 if (max_size < metaslab_df_alloc_threshold ||
541 free_pct < metaslab_df_free_pct) {
542 t = sm->sm_pp_root;
543 *cursor = 0;
544 }
545
546 return (metaslab_block_picker(t, cursor, size, 1ULL));
547}
548
549static boolean_t
550metaslab_df_fragmented(space_map_t *sm)
551{
552 uint64_t max_size = metaslab_pp_maxsize(sm);
553 int free_pct = sm->sm_space * 100 / sm->sm_size;
554
555 if (max_size >= metaslab_df_alloc_threshold &&
556 free_pct >= metaslab_df_free_pct)
557 return (B_FALSE);
558
559 return (B_TRUE);
560}
561
562static space_map_ops_t metaslab_df_ops = {
563 metaslab_pp_load,
564 metaslab_pp_unload,
565 metaslab_df_alloc,
566 metaslab_pp_claim,
567 metaslab_pp_free,
568 metaslab_pp_maxsize,
569 metaslab_df_fragmented
570};
571
572/*
573 * ==========================================================================
574 * Other experimental allocators
575 * ==========================================================================
576 */
577static uint64_t
578metaslab_cdf_alloc(space_map_t *sm, uint64_t size)
579{
580 avl_tree_t *t = &sm->sm_root;
581 uint64_t *cursor = (uint64_t *)sm->sm_ppd;
582 uint64_t *extent_end = (uint64_t *)sm->sm_ppd + 1;
583 uint64_t max_size = metaslab_pp_maxsize(sm);
584 uint64_t rsize = size;
585 uint64_t offset = 0;
586
587 ASSERT(MUTEX_HELD(sm->sm_lock));
588 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
589
590 if (max_size < size)
591 return (-1ULL);
592
593 ASSERT3U(*extent_end, >=, *cursor);
594
595 /*
596 * If we're running low on space switch to using the size
597 * sorted AVL tree (best-fit).
598 */
599 if ((*cursor + size) > *extent_end) {
600
601 t = sm->sm_pp_root;
602 *cursor = *extent_end = 0;
603
604 if (max_size > 2 * SPA_MAXBLOCKSIZE)
605 rsize = MIN(metaslab_min_alloc_size, max_size);
606 offset = metaslab_block_picker(t, extent_end, rsize, 1ULL);
607 if (offset != -1)
608 *cursor = offset + size;
609 } else {
610 offset = metaslab_block_picker(t, cursor, rsize, 1ULL);
611 }
612 ASSERT3U(*cursor, <=, *extent_end);
613 return (offset);
614}
615
616static boolean_t
617metaslab_cdf_fragmented(space_map_t *sm)
618{
619 uint64_t max_size = metaslab_pp_maxsize(sm);
620
621 if (max_size > (metaslab_min_alloc_size * 10))
622 return (B_FALSE);
623 return (B_TRUE);
624}
625
626static space_map_ops_t metaslab_cdf_ops = {
627 metaslab_pp_load,
628 metaslab_pp_unload,
629 metaslab_cdf_alloc,
630 metaslab_pp_claim,
631 metaslab_pp_free,
632 metaslab_pp_maxsize,
633 metaslab_cdf_fragmented
634};
635
636uint64_t metaslab_ndf_clump_shift = 4;
637
638static uint64_t
639metaslab_ndf_alloc(space_map_t *sm, uint64_t size)
640{
641 avl_tree_t *t = &sm->sm_root;
642 avl_index_t where;
643 space_seg_t *ss, ssearch;
644 uint64_t hbit = highbit(size);
645 uint64_t *cursor = (uint64_t *)sm->sm_ppd + hbit - 1;
646 uint64_t max_size = metaslab_pp_maxsize(sm);
647
648 ASSERT(MUTEX_HELD(sm->sm_lock));
649 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
650
651 if (max_size < size)
652 return (-1ULL);
653
654 ssearch.ss_start = *cursor;
655 ssearch.ss_end = *cursor + size;
656
657 ss = avl_find(t, &ssearch, &where);
658 if (ss == NULL || (ss->ss_start + size > ss->ss_end)) {
659 t = sm->sm_pp_root;
660
661 ssearch.ss_start = 0;
662 ssearch.ss_end = MIN(max_size,
663 1ULL << (hbit + metaslab_ndf_clump_shift));
664 ss = avl_find(t, &ssearch, &where);
665 if (ss == NULL)
666 ss = avl_nearest(t, where, AVL_AFTER);
667 ASSERT(ss != NULL);
668 }
669
670 if (ss != NULL) {
671 if (ss->ss_start + size <= ss->ss_end) {
672 *cursor = ss->ss_start + size;
673 return (ss->ss_start);
674 }
675 }
676 return (-1ULL);
677}
678
679static boolean_t
680metaslab_ndf_fragmented(space_map_t *sm)
681{
682 uint64_t max_size = metaslab_pp_maxsize(sm);
683
684 if (max_size > (metaslab_min_alloc_size << metaslab_ndf_clump_shift))
685 return (B_FALSE);
686 return (B_TRUE);
687}
688
689
690static space_map_ops_t metaslab_ndf_ops = {
691 metaslab_pp_load,
692 metaslab_pp_unload,
693 metaslab_ndf_alloc,
694 metaslab_pp_claim,
695 metaslab_pp_free,
696 metaslab_pp_maxsize,
697 metaslab_ndf_fragmented
698};
699
700space_map_ops_t *zfs_metaslab_ops = &metaslab_df_ops;
701
702/*
703 * ==========================================================================
704 * Metaslabs
705 * ==========================================================================
706 */
707metaslab_t *
708metaslab_init(metaslab_group_t *mg, space_map_obj_t *smo,
709 uint64_t start, uint64_t size, uint64_t txg)
710{
711 vdev_t *vd = mg->mg_vd;
712 metaslab_t *msp;
713
714 msp = kmem_zalloc(sizeof (metaslab_t), KM_SLEEP);
715 mutex_init(&msp->ms_lock, NULL, MUTEX_DEFAULT, NULL);
716
717 msp->ms_smo_syncing = *smo;
718
719 /*
720 * We create the main space map here, but we don't create the
721 * allocmaps and freemaps until metaslab_sync_done(). This serves
722 * two purposes: it allows metaslab_sync_done() to detect the
723 * addition of new space; and for debugging, it ensures that we'd
724 * data fault on any attempt to use this metaslab before it's ready.
725 */
726 space_map_create(&msp->ms_map, start, size,
727 vd->vdev_ashift, &msp->ms_lock);
728
729 metaslab_group_add(mg, msp);
730
731 if (metaslab_debug && smo->smo_object != 0) {
732 mutex_enter(&msp->ms_lock);
733 VERIFY(space_map_load(&msp->ms_map, mg->mg_class->mc_ops,
734 SM_FREE, smo, spa_meta_objset(vd->vdev_spa)) == 0);
735 mutex_exit(&msp->ms_lock);
736 }
737
738 /*
739 * If we're opening an existing pool (txg == 0) or creating
740 * a new one (txg == TXG_INITIAL), all space is available now.
741 * If we're adding space to an existing pool, the new space
742 * does not become available until after this txg has synced.
743 */
744 if (txg <= TXG_INITIAL)
745 metaslab_sync_done(msp, 0);
746
747 if (txg != 0) {
748 vdev_dirty(vd, 0, NULL, txg);
749 vdev_dirty(vd, VDD_METASLAB, msp, txg);
750 }
751
752 return (msp);
753}
754
755void
756metaslab_fini(metaslab_t *msp)
757{
758 metaslab_group_t *mg = msp->ms_group;
759
760 vdev_space_update(mg->mg_vd,
761 -msp->ms_smo.smo_alloc, 0, -msp->ms_map.sm_size);
762
763 metaslab_group_remove(mg, msp);
764
765 mutex_enter(&msp->ms_lock);
766
767 space_map_unload(&msp->ms_map);
768 space_map_destroy(&msp->ms_map);
769
770 for (int t = 0; t < TXG_SIZE; t++) {
771 space_map_destroy(&msp->ms_allocmap[t]);
772 space_map_destroy(&msp->ms_freemap[t]);
773 }
774
775 for (int t = 0; t < TXG_DEFER_SIZE; t++)
776 space_map_destroy(&msp->ms_defermap[t]);
777
778 ASSERT0(msp->ms_deferspace);
779
780 mutex_exit(&msp->ms_lock);
781 mutex_destroy(&msp->ms_lock);
782
783 kmem_free(msp, sizeof (metaslab_t));
784}
785
786#define METASLAB_WEIGHT_PRIMARY (1ULL << 63)
787#define METASLAB_WEIGHT_SECONDARY (1ULL << 62)
788#define METASLAB_ACTIVE_MASK \
789 (METASLAB_WEIGHT_PRIMARY | METASLAB_WEIGHT_SECONDARY)
790
791static uint64_t
792metaslab_weight(metaslab_t *msp)
793{
794 metaslab_group_t *mg = msp->ms_group;
795 space_map_t *sm = &msp->ms_map;
796 space_map_obj_t *smo = &msp->ms_smo;
797 vdev_t *vd = mg->mg_vd;
798 uint64_t weight, space;
799
800 ASSERT(MUTEX_HELD(&msp->ms_lock));
801
802 /*
803 * The baseline weight is the metaslab's free space.
804 */
805 space = sm->sm_size - smo->smo_alloc;
806 weight = space;
807
808 /*
809 * Modern disks have uniform bit density and constant angular velocity.
810 * Therefore, the outer recording zones are faster (higher bandwidth)
811 * than the inner zones by the ratio of outer to inner track diameter,
812 * which is typically around 2:1. We account for this by assigning
813 * higher weight to lower metaslabs (multiplier ranging from 2x to 1x).
814 * In effect, this means that we'll select the metaslab with the most
815 * free bandwidth rather than simply the one with the most free space.
816 */
817 weight = 2 * weight -
818 ((sm->sm_start >> vd->vdev_ms_shift) * weight) / vd->vdev_ms_count;
819 ASSERT(weight >= space && weight <= 2 * space);
820
821 /*
822 * For locality, assign higher weight to metaslabs which have
823 * a lower offset than what we've already activated.
824 */
825 if (sm->sm_start <= mg->mg_bonus_area)
826 weight *= (metaslab_smo_bonus_pct / 100);
827 ASSERT(weight >= space &&
828 weight <= 2 * (metaslab_smo_bonus_pct / 100) * space);
829
830 if (sm->sm_loaded && !sm->sm_ops->smop_fragmented(sm)) {
831 /*
832 * If this metaslab is one we're actively using, adjust its
833 * weight to make it preferable to any inactive metaslab so
834 * we'll polish it off.
835 */
836 weight |= (msp->ms_weight & METASLAB_ACTIVE_MASK);
837 }
838 return (weight);
839}
840
841static void
842metaslab_prefetch(metaslab_group_t *mg)
843{
844 spa_t *spa = mg->mg_vd->vdev_spa;
845 metaslab_t *msp;
846 avl_tree_t *t = &mg->mg_metaslab_tree;
847 int m;
848
849 mutex_enter(&mg->mg_lock);
850
851 /*
852 * Prefetch the next potential metaslabs
853 */
854 for (msp = avl_first(t), m = 0; msp; msp = AVL_NEXT(t, msp), m++) {
855 space_map_t *sm = &msp->ms_map;
856 space_map_obj_t *smo = &msp->ms_smo;
857
858 /* If we have reached our prefetch limit then we're done */
859 if (m >= metaslab_prefetch_limit)
860 break;
861
862 if (!sm->sm_loaded && smo->smo_object != 0) {
863 mutex_exit(&mg->mg_lock);
864 dmu_prefetch(spa_meta_objset(spa), smo->smo_object,
865 0ULL, smo->smo_objsize);
866 mutex_enter(&mg->mg_lock);
867 }
868 }
869 mutex_exit(&mg->mg_lock);
870}
871
872static int
873metaslab_activate(metaslab_t *msp, uint64_t activation_weight)
874{
875 metaslab_group_t *mg = msp->ms_group;
876 space_map_t *sm = &msp->ms_map;
877 space_map_ops_t *sm_ops = msp->ms_group->mg_class->mc_ops;
878
879 ASSERT(MUTEX_HELD(&msp->ms_lock));
880
881 if ((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
882 space_map_load_wait(sm);
883 if (!sm->sm_loaded) {
884 space_map_obj_t *smo = &msp->ms_smo;
885
886 int error = space_map_load(sm, sm_ops, SM_FREE, smo,
887 spa_meta_objset(msp->ms_group->mg_vd->vdev_spa));
888 if (error) {
889 metaslab_group_sort(msp->ms_group, msp, 0);
890 return (error);
891 }
892 for (int t = 0; t < TXG_DEFER_SIZE; t++)
893 space_map_walk(&msp->ms_defermap[t],
894 space_map_claim, sm);
895
896 }
897
898 /*
899 * Track the bonus area as we activate new metaslabs.
900 */
901 if (sm->sm_start > mg->mg_bonus_area) {
902 mutex_enter(&mg->mg_lock);
903 mg->mg_bonus_area = sm->sm_start;
904 mutex_exit(&mg->mg_lock);
905 }
906
907 metaslab_group_sort(msp->ms_group, msp,
908 msp->ms_weight | activation_weight);
909 }
910 ASSERT(sm->sm_loaded);
911 ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK);
912
913 return (0);
914}
915
916static void
917metaslab_passivate(metaslab_t *msp, uint64_t size)
918{
919 /*
920 * If size < SPA_MINBLOCKSIZE, then we will not allocate from
921 * this metaslab again. In that case, it had better be empty,
922 * or we would be leaving space on the table.
923 */
924 ASSERT(size >= SPA_MINBLOCKSIZE || msp->ms_map.sm_space == 0);
925 metaslab_group_sort(msp->ms_group, msp, MIN(msp->ms_weight, size));
926 ASSERT((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0);
927}
928
929/*
930 * Write a metaslab to disk in the context of the specified transaction group.
931 */
932void
933metaslab_sync(metaslab_t *msp, uint64_t txg)
934{
935 vdev_t *vd = msp->ms_group->mg_vd;
936 spa_t *spa = vd->vdev_spa;
937 objset_t *mos = spa_meta_objset(spa);
938 space_map_t *allocmap = &msp->ms_allocmap[txg & TXG_MASK];
939 space_map_t *freemap = &msp->ms_freemap[txg & TXG_MASK];
940 space_map_t *freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
941 space_map_t *sm = &msp->ms_map;
942 space_map_obj_t *smo = &msp->ms_smo_syncing;
943 dmu_buf_t *db;
944 dmu_tx_t *tx;
945
946 ASSERT(!vd->vdev_ishole);
947
948 if (allocmap->sm_space == 0 && freemap->sm_space == 0)
949 return;
950
951 /*
952 * The only state that can actually be changing concurrently with
953 * metaslab_sync() is the metaslab's ms_map. No other thread can
954 * be modifying this txg's allocmap, freemap, freed_map, or smo.
955 * Therefore, we only hold ms_lock to satify space_map ASSERTs.
956 * We drop it whenever we call into the DMU, because the DMU
957 * can call down to us (e.g. via zio_free()) at any time.
958 */
959
960 tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg);
961
962 if (smo->smo_object == 0) {
963 ASSERT(smo->smo_objsize == 0);
964 ASSERT(smo->smo_alloc == 0);
965 smo->smo_object = dmu_object_alloc(mos,
966 DMU_OT_SPACE_MAP, 1 << SPACE_MAP_BLOCKSHIFT,
967 DMU_OT_SPACE_MAP_HEADER, sizeof (*smo), tx);
968 ASSERT(smo->smo_object != 0);
969 dmu_write(mos, vd->vdev_ms_array, sizeof (uint64_t) *
970 (sm->sm_start >> vd->vdev_ms_shift),
971 sizeof (uint64_t), &smo->smo_object, tx);
972 }
973
974 mutex_enter(&msp->ms_lock);
975
976 space_map_walk(freemap, space_map_add, freed_map);
977
978 if (sm->sm_loaded && spa_sync_pass(spa) == 1 && smo->smo_objsize >=
979 2 * sizeof (uint64_t) * avl_numnodes(&sm->sm_root)) {
980 /*
981 * The in-core space map representation is twice as compact
982 * as the on-disk one, so it's time to condense the latter
983 * by generating a pure allocmap from first principles.
984 *
985 * This metaslab is 100% allocated,
986 * minus the content of the in-core map (sm),
987 * minus what's been freed this txg (freed_map),
988 * minus deferred frees (ms_defermap[]),
989 * minus allocations from txgs in the future
990 * (because they haven't been committed yet).
991 */
992 space_map_vacate(allocmap, NULL, NULL);
993 space_map_vacate(freemap, NULL, NULL);
994
995 space_map_add(allocmap, allocmap->sm_start, allocmap->sm_size);
996
997 space_map_walk(sm, space_map_remove, allocmap);
998 space_map_walk(freed_map, space_map_remove, allocmap);
999
1000 for (int t = 0; t < TXG_DEFER_SIZE; t++)
1001 space_map_walk(&msp->ms_defermap[t],
1002 space_map_remove, allocmap);
1003
1004 for (int t = 1; t < TXG_CONCURRENT_STATES; t++)
1005 space_map_walk(&msp->ms_allocmap[(txg + t) & TXG_MASK],
1006 space_map_remove, allocmap);
1007
1008 mutex_exit(&msp->ms_lock);
1009 space_map_truncate(smo, mos, tx);
1010 mutex_enter(&msp->ms_lock);
1011 }
1012
1013 space_map_sync(allocmap, SM_ALLOC, smo, mos, tx);
1014 space_map_sync(freemap, SM_FREE, smo, mos, tx);
1015
1016 mutex_exit(&msp->ms_lock);
1017
1018 VERIFY(0 == dmu_bonus_hold(mos, smo->smo_object, FTAG, &db));
1019 dmu_buf_will_dirty(db, tx);
1020 ASSERT3U(db->db_size, >=, sizeof (*smo));
1021 bcopy(smo, db->db_data, sizeof (*smo));
1022 dmu_buf_rele(db, FTAG);
1023
1024 dmu_tx_commit(tx);
1025}
1026
1027/*
1028 * Called after a transaction group has completely synced to mark
1029 * all of the metaslab's free space as usable.
1030 */
1031void
1032metaslab_sync_done(metaslab_t *msp, uint64_t txg)
1033{
1034 space_map_obj_t *smo = &msp->ms_smo;
1035 space_map_obj_t *smosync = &msp->ms_smo_syncing;
1036 space_map_t *sm = &msp->ms_map;
1037 space_map_t *freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
1038 space_map_t *defer_map = &msp->ms_defermap[txg % TXG_DEFER_SIZE];
1039 metaslab_group_t *mg = msp->ms_group;
1040 vdev_t *vd = mg->mg_vd;
1041 int64_t alloc_delta, defer_delta;
1042
1043 ASSERT(!vd->vdev_ishole);
1044
1045 mutex_enter(&msp->ms_lock);
1046
1047 /*
1048 * If this metaslab is just becoming available, initialize its
1049 * allocmaps and freemaps and add its capacity to the vdev.
1050 */
1051 if (freed_map->sm_size == 0) {
1052 for (int t = 0; t < TXG_SIZE; t++) {
1053 space_map_create(&msp->ms_allocmap[t], sm->sm_start,
1054 sm->sm_size, sm->sm_shift, sm->sm_lock);
1055 space_map_create(&msp->ms_freemap[t], sm->sm_start,
1056 sm->sm_size, sm->sm_shift, sm->sm_lock);
1057 }
1058
1059 for (int t = 0; t < TXG_DEFER_SIZE; t++)
1060 space_map_create(&msp->ms_defermap[t], sm->sm_start,
1061 sm->sm_size, sm->sm_shift, sm->sm_lock);
1062
1063 vdev_space_update(vd, 0, 0, sm->sm_size);
1064 }
1065
1066 alloc_delta = smosync->smo_alloc - smo->smo_alloc;
1067 defer_delta = freed_map->sm_space - defer_map->sm_space;
1068
1069 vdev_space_update(vd, alloc_delta + defer_delta, defer_delta, 0);
1070
1071 ASSERT(msp->ms_allocmap[txg & TXG_MASK].sm_space == 0);
1072 ASSERT(msp->ms_freemap[txg & TXG_MASK].sm_space == 0);
1073
1074 /*
1075 * If there's a space_map_load() in progress, wait for it to complete
1076 * so that we have a consistent view of the in-core space map.
1077 * Then, add defer_map (oldest deferred frees) to this map and
1078 * transfer freed_map (this txg's frees) to defer_map.
1079 */
1080 space_map_load_wait(sm);
1081 space_map_vacate(defer_map, sm->sm_loaded ? space_map_free : NULL, sm);
1082 space_map_vacate(freed_map, space_map_add, defer_map);
1083
1084 *smo = *smosync;
1085
1086 msp->ms_deferspace += defer_delta;
1087 ASSERT3S(msp->ms_deferspace, >=, 0);
1088 ASSERT3S(msp->ms_deferspace, <=, sm->sm_size);
1089 if (msp->ms_deferspace != 0) {
1090 /*
1091 * Keep syncing this metaslab until all deferred frees
1092 * are back in circulation.
1093 */
1094 vdev_dirty(vd, VDD_METASLAB, msp, txg + 1);
1095 }
1096
1097 /*
1098 * If the map is loaded but no longer active, evict it as soon as all
1099 * future allocations have synced. (If we unloaded it now and then
1100 * loaded a moment later, the map wouldn't reflect those allocations.)
1101 */
1102 if (sm->sm_loaded && (msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
1103 int evictable = 1;
1104
1105 for (int t = 1; t < TXG_CONCURRENT_STATES; t++)
1106 if (msp->ms_allocmap[(txg + t) & TXG_MASK].sm_space)
1107 evictable = 0;
1108
1109 if (evictable && !metaslab_debug)
1110 space_map_unload(sm);
1111 }
1112
1113 metaslab_group_sort(mg, msp, metaslab_weight(msp));
1114
1115 mutex_exit(&msp->ms_lock);
1116}
1117
1118void
1119metaslab_sync_reassess(metaslab_group_t *mg)
1120{
1121 vdev_t *vd = mg->mg_vd;
1122 int64_t failures = mg->mg_alloc_failures;
1123
1124 /*
1125 * Re-evaluate all metaslabs which have lower offsets than the
1126 * bonus area.
1127 */
1128 for (int m = 0; m < vd->vdev_ms_count; m++) {
1129 metaslab_t *msp = vd->vdev_ms[m];
1130
1131 if (msp->ms_map.sm_start > mg->mg_bonus_area)
1132 break;
1133
1134 mutex_enter(&msp->ms_lock);
1135 metaslab_group_sort(mg, msp, metaslab_weight(msp));
1136 mutex_exit(&msp->ms_lock);
1137 }
1138
1139 atomic_add_64(&mg->mg_alloc_failures, -failures);
1140
1141 /*
1142 * Prefetch the next potential metaslabs
1143 */
1144 metaslab_prefetch(mg);
1145}
1146
1147static uint64_t
1148metaslab_distance(metaslab_t *msp, dva_t *dva)
1149{
1150 uint64_t ms_shift = msp->ms_group->mg_vd->vdev_ms_shift;
1151 uint64_t offset = DVA_GET_OFFSET(dva) >> ms_shift;
1152 uint64_t start = msp->ms_map.sm_start >> ms_shift;
1153
1154 if (msp->ms_group->mg_vd->vdev_id != DVA_GET_VDEV(dva))
1155 return (1ULL << 63);
1156
1157 if (offset < start)
1158 return ((start - offset) << ms_shift);
1159 if (offset > start)
1160 return ((offset - start) << ms_shift);
1161 return (0);
1162}
1163
1164static uint64_t
1165metaslab_group_alloc(metaslab_group_t *mg, uint64_t psize, uint64_t asize,
1166 uint64_t txg, uint64_t min_distance, dva_t *dva, int d, int flags)
1167{
1168 spa_t *spa = mg->mg_vd->vdev_spa;
1169 metaslab_t *msp = NULL;
1170 uint64_t offset = -1ULL;
1171 avl_tree_t *t = &mg->mg_metaslab_tree;
1172 uint64_t activation_weight;
1173 uint64_t target_distance;
1174 int i;
1175
1176 activation_weight = METASLAB_WEIGHT_PRIMARY;
1177 for (i = 0; i < d; i++) {
1178 if (DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) {
1179 activation_weight = METASLAB_WEIGHT_SECONDARY;
1180 break;
1181 }
1182 }
1183
1184 for (;;) {
1185 boolean_t was_active;
1186
1187 mutex_enter(&mg->mg_lock);
1188 for (msp = avl_first(t); msp; msp = AVL_NEXT(t, msp)) {
1189 if (msp->ms_weight < asize) {
1190 spa_dbgmsg(spa, "%s: failed to meet weight "
1191 "requirement: vdev %llu, txg %llu, mg %p, "
1192 "msp %p, psize %llu, asize %llu, "
1193 "failures %llu, weight %llu",
1194 spa_name(spa), mg->mg_vd->vdev_id, txg,
1195 mg, msp, psize, asize,
1196 mg->mg_alloc_failures, msp->ms_weight);
1197 mutex_exit(&mg->mg_lock);
1198 return (-1ULL);
1199 }
1200 was_active = msp->ms_weight & METASLAB_ACTIVE_MASK;
1201 if (activation_weight == METASLAB_WEIGHT_PRIMARY)
1202 break;
1203
1204 target_distance = min_distance +
1205 (msp->ms_smo.smo_alloc ? 0 : min_distance >> 1);
1206
1207 for (i = 0; i < d; i++)
1208 if (metaslab_distance(msp, &dva[i]) <
1209 target_distance)
1210 break;
1211 if (i == d)
1212 break;
1213 }
1214 mutex_exit(&mg->mg_lock);
1215 if (msp == NULL)
1216 return (-1ULL);
1217
1218 /*
1219 * If we've already reached the allowable number of failed
1220 * allocation attempts on this metaslab group then we
1221 * consider skipping it. We skip it only if we're allowed
1222 * to "fast" gang, the physical size is larger than
1223 * a gang block, and we're attempting to allocate from
1224 * the primary metaslab.
1225 */
1226 if (mg->mg_alloc_failures > zfs_mg_alloc_failures &&
1227 CAN_FASTGANG(flags) && psize > SPA_GANGBLOCKSIZE &&
1228 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1229 spa_dbgmsg(spa, "%s: skipping metaslab group: "
1230 "vdev %llu, txg %llu, mg %p, psize %llu, "
1231 "asize %llu, failures %llu", spa_name(spa),
1232 mg->mg_vd->vdev_id, txg, mg, psize, asize,
1233 mg->mg_alloc_failures);
1234 return (-1ULL);
1235 }
1236
1237 mutex_enter(&msp->ms_lock);
1238
1239 /*
1240 * Ensure that the metaslab we have selected is still
1241 * capable of handling our request. It's possible that
1242 * another thread may have changed the weight while we
1243 * were blocked on the metaslab lock.
1244 */
1245 if (msp->ms_weight < asize || (was_active &&
1246 !(msp->ms_weight & METASLAB_ACTIVE_MASK) &&
1247 activation_weight == METASLAB_WEIGHT_PRIMARY)) {
1248 mutex_exit(&msp->ms_lock);
1249 continue;
1250 }
1251
1252 if ((msp->ms_weight & METASLAB_WEIGHT_SECONDARY) &&
1253 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1254 metaslab_passivate(msp,
1255 msp->ms_weight & ~METASLAB_ACTIVE_MASK);
1256 mutex_exit(&msp->ms_lock);
1257 continue;
1258 }
1259
1260 if (metaslab_activate(msp, activation_weight) != 0) {
1261 mutex_exit(&msp->ms_lock);
1262 continue;
1263 }
1264
1265 if ((offset = space_map_alloc(&msp->ms_map, asize)) != -1ULL)
1266 break;
1267
1268 atomic_inc_64(&mg->mg_alloc_failures);
1269
1270 metaslab_passivate(msp, space_map_maxsize(&msp->ms_map));
1271
1272 mutex_exit(&msp->ms_lock);
1273 }
1274
1275 if (msp->ms_allocmap[txg & TXG_MASK].sm_space == 0)
1276 vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg);
1277
1278 space_map_add(&msp->ms_allocmap[txg & TXG_MASK], offset, asize);
1279
1280 mutex_exit(&msp->ms_lock);
1281
1282 return (offset);
1283}
1284
1285/*
1286 * Allocate a block for the specified i/o.
1287 */
1288static int
1289metaslab_alloc_dva(spa_t *spa, metaslab_class_t *mc, uint64_t psize,
1290 dva_t *dva, int d, dva_t *hintdva, uint64_t txg, int flags)
1291{
1292 metaslab_group_t *mg, *rotor;
1293 vdev_t *vd;
1294 int dshift = 3;
1295 int all_zero;
1296 int zio_lock = B_FALSE;
1297 boolean_t allocatable;
1298 uint64_t offset = -1ULL;
1299 uint64_t asize;
1300 uint64_t distance;
1301
1302 ASSERT(!DVA_IS_VALID(&dva[d]));
1303
1304 /*
1305 * For testing, make some blocks above a certain size be gang blocks.
1306 */
1307 if (psize >= metaslab_gang_bang && (ddi_get_lbolt() & 3) == 0)
1308 return (ENOSPC);
1309
1310 /*
1311 * Start at the rotor and loop through all mgs until we find something.
1312 * Note that there's no locking on mc_rotor or mc_aliquot because
1313 * nothing actually breaks if we miss a few updates -- we just won't
1314 * allocate quite as evenly. It all balances out over time.
1315 *
1316 * If we are doing ditto or log blocks, try to spread them across
1317 * consecutive vdevs. If we're forced to reuse a vdev before we've
1318 * allocated all of our ditto blocks, then try and spread them out on
1319 * that vdev as much as possible. If it turns out to not be possible,
1320 * gradually lower our standards until anything becomes acceptable.
1321 * Also, allocating on consecutive vdevs (as opposed to random vdevs)
1322 * gives us hope of containing our fault domains to something we're
1323 * able to reason about. Otherwise, any two top-level vdev failures
1324 * will guarantee the loss of data. With consecutive allocation,
1325 * only two adjacent top-level vdev failures will result in data loss.
1326 *
1327 * If we are doing gang blocks (hintdva is non-NULL), try to keep
1328 * ourselves on the same vdev as our gang block header. That
1329 * way, we can hope for locality in vdev_cache, plus it makes our
1330 * fault domains something tractable.
1331 */
1332 if (hintdva) {
1333 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&hintdva[d]));
1334
1335 /*
1336 * It's possible the vdev we're using as the hint no
1337 * longer exists (i.e. removed). Consult the rotor when
1338 * all else fails.
1339 */
1340 if (vd != NULL) {
1341 mg = vd->vdev_mg;
1342
1343 if (flags & METASLAB_HINTBP_AVOID &&
1344 mg->mg_next != NULL)
1345 mg = mg->mg_next;
1346 } else {
1347 mg = mc->mc_rotor;
1348 }
1349 } else if (d != 0) {
1350 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[d - 1]));
1351 mg = vd->vdev_mg->mg_next;
1352 } else {
1353 mg = mc->mc_rotor;
1354 }
1355
1356 /*
1357 * If the hint put us into the wrong metaslab class, or into a
1358 * metaslab group that has been passivated, just follow the rotor.
1359 */
1360 if (mg->mg_class != mc || mg->mg_activation_count <= 0)
1361 mg = mc->mc_rotor;
1362
1363 rotor = mg;
1364top:
1365 all_zero = B_TRUE;
1366 do {
1367 ASSERT(mg->mg_activation_count == 1);
1368
1369 vd = mg->mg_vd;
1370
1371 /*
1372 * Don't allocate from faulted devices.
1373 */
1374 if (zio_lock) {
1375 spa_config_enter(spa, SCL_ZIO, FTAG, RW_READER);
1376 allocatable = vdev_allocatable(vd);
1377 spa_config_exit(spa, SCL_ZIO, FTAG);
1378 } else {
1379 allocatable = vdev_allocatable(vd);
1380 }
1381 if (!allocatable)
1382 goto next;
1383
1384 /*
1385 * Avoid writing single-copy data to a failing vdev
| 110 * ==========================================================================
111 * Metaslab classes
112 * ==========================================================================
113 */
114metaslab_class_t *
115metaslab_class_create(spa_t *spa, space_map_ops_t *ops)
116{
117 metaslab_class_t *mc;
118
119 mc = kmem_zalloc(sizeof (metaslab_class_t), KM_SLEEP);
120
121 mc->mc_spa = spa;
122 mc->mc_rotor = NULL;
123 mc->mc_ops = ops;
124
125 return (mc);
126}
127
128void
129metaslab_class_destroy(metaslab_class_t *mc)
130{
131 ASSERT(mc->mc_rotor == NULL);
132 ASSERT(mc->mc_alloc == 0);
133 ASSERT(mc->mc_deferred == 0);
134 ASSERT(mc->mc_space == 0);
135 ASSERT(mc->mc_dspace == 0);
136
137 kmem_free(mc, sizeof (metaslab_class_t));
138}
139
140int
141metaslab_class_validate(metaslab_class_t *mc)
142{
143 metaslab_group_t *mg;
144 vdev_t *vd;
145
146 /*
147 * Must hold one of the spa_config locks.
148 */
149 ASSERT(spa_config_held(mc->mc_spa, SCL_ALL, RW_READER) ||
150 spa_config_held(mc->mc_spa, SCL_ALL, RW_WRITER));
151
152 if ((mg = mc->mc_rotor) == NULL)
153 return (0);
154
155 do {
156 vd = mg->mg_vd;
157 ASSERT(vd->vdev_mg != NULL);
158 ASSERT3P(vd->vdev_top, ==, vd);
159 ASSERT3P(mg->mg_class, ==, mc);
160 ASSERT3P(vd->vdev_ops, !=, &vdev_hole_ops);
161 } while ((mg = mg->mg_next) != mc->mc_rotor);
162
163 return (0);
164}
165
166void
167metaslab_class_space_update(metaslab_class_t *mc, int64_t alloc_delta,
168 int64_t defer_delta, int64_t space_delta, int64_t dspace_delta)
169{
170 atomic_add_64(&mc->mc_alloc, alloc_delta);
171 atomic_add_64(&mc->mc_deferred, defer_delta);
172 atomic_add_64(&mc->mc_space, space_delta);
173 atomic_add_64(&mc->mc_dspace, dspace_delta);
174}
175
176uint64_t
177metaslab_class_get_alloc(metaslab_class_t *mc)
178{
179 return (mc->mc_alloc);
180}
181
182uint64_t
183metaslab_class_get_deferred(metaslab_class_t *mc)
184{
185 return (mc->mc_deferred);
186}
187
188uint64_t
189metaslab_class_get_space(metaslab_class_t *mc)
190{
191 return (mc->mc_space);
192}
193
194uint64_t
195metaslab_class_get_dspace(metaslab_class_t *mc)
196{
197 return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space);
198}
199
200/*
201 * ==========================================================================
202 * Metaslab groups
203 * ==========================================================================
204 */
205static int
206metaslab_compare(const void *x1, const void *x2)
207{
208 const metaslab_t *m1 = x1;
209 const metaslab_t *m2 = x2;
210
211 if (m1->ms_weight < m2->ms_weight)
212 return (1);
213 if (m1->ms_weight > m2->ms_weight)
214 return (-1);
215
216 /*
217 * If the weights are identical, use the offset to force uniqueness.
218 */
219 if (m1->ms_map.sm_start < m2->ms_map.sm_start)
220 return (-1);
221 if (m1->ms_map.sm_start > m2->ms_map.sm_start)
222 return (1);
223
224 ASSERT3P(m1, ==, m2);
225
226 return (0);
227}
228
229metaslab_group_t *
230metaslab_group_create(metaslab_class_t *mc, vdev_t *vd)
231{
232 metaslab_group_t *mg;
233
234 mg = kmem_zalloc(sizeof (metaslab_group_t), KM_SLEEP);
235 mutex_init(&mg->mg_lock, NULL, MUTEX_DEFAULT, NULL);
236 avl_create(&mg->mg_metaslab_tree, metaslab_compare,
237 sizeof (metaslab_t), offsetof(struct metaslab, ms_group_node));
238 mg->mg_vd = vd;
239 mg->mg_class = mc;
240 mg->mg_activation_count = 0;
241
242 return (mg);
243}
244
245void
246metaslab_group_destroy(metaslab_group_t *mg)
247{
248 ASSERT(mg->mg_prev == NULL);
249 ASSERT(mg->mg_next == NULL);
250 /*
251 * We may have gone below zero with the activation count
252 * either because we never activated in the first place or
253 * because we're done, and possibly removing the vdev.
254 */
255 ASSERT(mg->mg_activation_count <= 0);
256
257 avl_destroy(&mg->mg_metaslab_tree);
258 mutex_destroy(&mg->mg_lock);
259 kmem_free(mg, sizeof (metaslab_group_t));
260}
261
262void
263metaslab_group_activate(metaslab_group_t *mg)
264{
265 metaslab_class_t *mc = mg->mg_class;
266 metaslab_group_t *mgprev, *mgnext;
267
268 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
269
270 ASSERT(mc->mc_rotor != mg);
271 ASSERT(mg->mg_prev == NULL);
272 ASSERT(mg->mg_next == NULL);
273 ASSERT(mg->mg_activation_count <= 0);
274
275 if (++mg->mg_activation_count <= 0)
276 return;
277
278 mg->mg_aliquot = metaslab_aliquot * MAX(1, mg->mg_vd->vdev_children);
279
280 if ((mgprev = mc->mc_rotor) == NULL) {
281 mg->mg_prev = mg;
282 mg->mg_next = mg;
283 } else {
284 mgnext = mgprev->mg_next;
285 mg->mg_prev = mgprev;
286 mg->mg_next = mgnext;
287 mgprev->mg_next = mg;
288 mgnext->mg_prev = mg;
289 }
290 mc->mc_rotor = mg;
291}
292
293void
294metaslab_group_passivate(metaslab_group_t *mg)
295{
296 metaslab_class_t *mc = mg->mg_class;
297 metaslab_group_t *mgprev, *mgnext;
298
299 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
300
301 if (--mg->mg_activation_count != 0) {
302 ASSERT(mc->mc_rotor != mg);
303 ASSERT(mg->mg_prev == NULL);
304 ASSERT(mg->mg_next == NULL);
305 ASSERT(mg->mg_activation_count < 0);
306 return;
307 }
308
309 mgprev = mg->mg_prev;
310 mgnext = mg->mg_next;
311
312 if (mg == mgnext) {
313 mc->mc_rotor = NULL;
314 } else {
315 mc->mc_rotor = mgnext;
316 mgprev->mg_next = mgnext;
317 mgnext->mg_prev = mgprev;
318 }
319
320 mg->mg_prev = NULL;
321 mg->mg_next = NULL;
322}
323
324static void
325metaslab_group_add(metaslab_group_t *mg, metaslab_t *msp)
326{
327 mutex_enter(&mg->mg_lock);
328 ASSERT(msp->ms_group == NULL);
329 msp->ms_group = mg;
330 msp->ms_weight = 0;
331 avl_add(&mg->mg_metaslab_tree, msp);
332 mutex_exit(&mg->mg_lock);
333}
334
335static void
336metaslab_group_remove(metaslab_group_t *mg, metaslab_t *msp)
337{
338 mutex_enter(&mg->mg_lock);
339 ASSERT(msp->ms_group == mg);
340 avl_remove(&mg->mg_metaslab_tree, msp);
341 msp->ms_group = NULL;
342 mutex_exit(&mg->mg_lock);
343}
344
345static void
346metaslab_group_sort(metaslab_group_t *mg, metaslab_t *msp, uint64_t weight)
347{
348 /*
349 * Although in principle the weight can be any value, in
350 * practice we do not use values in the range [1, 510].
351 */
352 ASSERT(weight >= SPA_MINBLOCKSIZE-1 || weight == 0);
353 ASSERT(MUTEX_HELD(&msp->ms_lock));
354
355 mutex_enter(&mg->mg_lock);
356 ASSERT(msp->ms_group == mg);
357 avl_remove(&mg->mg_metaslab_tree, msp);
358 msp->ms_weight = weight;
359 avl_add(&mg->mg_metaslab_tree, msp);
360 mutex_exit(&mg->mg_lock);
361}
362
363/*
364 * ==========================================================================
365 * Common allocator routines
366 * ==========================================================================
367 */
368static int
369metaslab_segsize_compare(const void *x1, const void *x2)
370{
371 const space_seg_t *s1 = x1;
372 const space_seg_t *s2 = x2;
373 uint64_t ss_size1 = s1->ss_end - s1->ss_start;
374 uint64_t ss_size2 = s2->ss_end - s2->ss_start;
375
376 if (ss_size1 < ss_size2)
377 return (-1);
378 if (ss_size1 > ss_size2)
379 return (1);
380
381 if (s1->ss_start < s2->ss_start)
382 return (-1);
383 if (s1->ss_start > s2->ss_start)
384 return (1);
385
386 return (0);
387}
388
389/*
390 * This is a helper function that can be used by the allocator to find
391 * a suitable block to allocate. This will search the specified AVL
392 * tree looking for a block that matches the specified criteria.
393 */
394static uint64_t
395metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size,
396 uint64_t align)
397{
398 space_seg_t *ss, ssearch;
399 avl_index_t where;
400
401 ssearch.ss_start = *cursor;
402 ssearch.ss_end = *cursor + size;
403
404 ss = avl_find(t, &ssearch, &where);
405 if (ss == NULL)
406 ss = avl_nearest(t, where, AVL_AFTER);
407
408 while (ss != NULL) {
409 uint64_t offset = P2ROUNDUP(ss->ss_start, align);
410
411 if (offset + size <= ss->ss_end) {
412 *cursor = offset + size;
413 return (offset);
414 }
415 ss = AVL_NEXT(t, ss);
416 }
417
418 /*
419 * If we know we've searched the whole map (*cursor == 0), give up.
420 * Otherwise, reset the cursor to the beginning and try again.
421 */
422 if (*cursor == 0)
423 return (-1ULL);
424
425 *cursor = 0;
426 return (metaslab_block_picker(t, cursor, size, align));
427}
428
429static void
430metaslab_pp_load(space_map_t *sm)
431{
432 space_seg_t *ss;
433
434 ASSERT(sm->sm_ppd == NULL);
435 sm->sm_ppd = kmem_zalloc(64 * sizeof (uint64_t), KM_SLEEP);
436
437 sm->sm_pp_root = kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
438 avl_create(sm->sm_pp_root, metaslab_segsize_compare,
439 sizeof (space_seg_t), offsetof(struct space_seg, ss_pp_node));
440
441 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
442 avl_add(sm->sm_pp_root, ss);
443}
444
445static void
446metaslab_pp_unload(space_map_t *sm)
447{
448 void *cookie = NULL;
449
450 kmem_free(sm->sm_ppd, 64 * sizeof (uint64_t));
451 sm->sm_ppd = NULL;
452
453 while (avl_destroy_nodes(sm->sm_pp_root, &cookie) != NULL) {
454 /* tear down the tree */
455 }
456
457 avl_destroy(sm->sm_pp_root);
458 kmem_free(sm->sm_pp_root, sizeof (avl_tree_t));
459 sm->sm_pp_root = NULL;
460}
461
462/* ARGSUSED */
463static void
464metaslab_pp_claim(space_map_t *sm, uint64_t start, uint64_t size)
465{
466 /* No need to update cursor */
467}
468
469/* ARGSUSED */
470static void
471metaslab_pp_free(space_map_t *sm, uint64_t start, uint64_t size)
472{
473 /* No need to update cursor */
474}
475
476/*
477 * Return the maximum contiguous segment within the metaslab.
478 */
479uint64_t
480metaslab_pp_maxsize(space_map_t *sm)
481{
482 avl_tree_t *t = sm->sm_pp_root;
483 space_seg_t *ss;
484
485 if (t == NULL || (ss = avl_last(t)) == NULL)
486 return (0ULL);
487
488 return (ss->ss_end - ss->ss_start);
489}
490
491/*
492 * ==========================================================================
493 * The first-fit block allocator
494 * ==========================================================================
495 */
496static uint64_t
497metaslab_ff_alloc(space_map_t *sm, uint64_t size)
498{
499 avl_tree_t *t = &sm->sm_root;
500 uint64_t align = size & -size;
501 uint64_t *cursor = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
502
503 return (metaslab_block_picker(t, cursor, size, align));
504}
505
506/* ARGSUSED */
507boolean_t
508metaslab_ff_fragmented(space_map_t *sm)
509{
510 return (B_TRUE);
511}
512
513static space_map_ops_t metaslab_ff_ops = {
514 metaslab_pp_load,
515 metaslab_pp_unload,
516 metaslab_ff_alloc,
517 metaslab_pp_claim,
518 metaslab_pp_free,
519 metaslab_pp_maxsize,
520 metaslab_ff_fragmented
521};
522
523/*
524 * ==========================================================================
525 * Dynamic block allocator -
526 * Uses the first fit allocation scheme until space get low and then
527 * adjusts to a best fit allocation method. Uses metaslab_df_alloc_threshold
528 * and metaslab_df_free_pct to determine when to switch the allocation scheme.
529 * ==========================================================================
530 */
531static uint64_t
532metaslab_df_alloc(space_map_t *sm, uint64_t size)
533{
534 avl_tree_t *t = &sm->sm_root;
535 uint64_t align = size & -size;
536 uint64_t *cursor = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
537 uint64_t max_size = metaslab_pp_maxsize(sm);
538 int free_pct = sm->sm_space * 100 / sm->sm_size;
539
540 ASSERT(MUTEX_HELD(sm->sm_lock));
541 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
542
543 if (max_size < size)
544 return (-1ULL);
545
546 /*
547 * If we're running low on space switch to using the size
548 * sorted AVL tree (best-fit).
549 */
550 if (max_size < metaslab_df_alloc_threshold ||
551 free_pct < metaslab_df_free_pct) {
552 t = sm->sm_pp_root;
553 *cursor = 0;
554 }
555
556 return (metaslab_block_picker(t, cursor, size, 1ULL));
557}
558
559static boolean_t
560metaslab_df_fragmented(space_map_t *sm)
561{
562 uint64_t max_size = metaslab_pp_maxsize(sm);
563 int free_pct = sm->sm_space * 100 / sm->sm_size;
564
565 if (max_size >= metaslab_df_alloc_threshold &&
566 free_pct >= metaslab_df_free_pct)
567 return (B_FALSE);
568
569 return (B_TRUE);
570}
571
572static space_map_ops_t metaslab_df_ops = {
573 metaslab_pp_load,
574 metaslab_pp_unload,
575 metaslab_df_alloc,
576 metaslab_pp_claim,
577 metaslab_pp_free,
578 metaslab_pp_maxsize,
579 metaslab_df_fragmented
580};
581
582/*
583 * ==========================================================================
584 * Other experimental allocators
585 * ==========================================================================
586 */
587static uint64_t
588metaslab_cdf_alloc(space_map_t *sm, uint64_t size)
589{
590 avl_tree_t *t = &sm->sm_root;
591 uint64_t *cursor = (uint64_t *)sm->sm_ppd;
592 uint64_t *extent_end = (uint64_t *)sm->sm_ppd + 1;
593 uint64_t max_size = metaslab_pp_maxsize(sm);
594 uint64_t rsize = size;
595 uint64_t offset = 0;
596
597 ASSERT(MUTEX_HELD(sm->sm_lock));
598 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
599
600 if (max_size < size)
601 return (-1ULL);
602
603 ASSERT3U(*extent_end, >=, *cursor);
604
605 /*
606 * If we're running low on space switch to using the size
607 * sorted AVL tree (best-fit).
608 */
609 if ((*cursor + size) > *extent_end) {
610
611 t = sm->sm_pp_root;
612 *cursor = *extent_end = 0;
613
614 if (max_size > 2 * SPA_MAXBLOCKSIZE)
615 rsize = MIN(metaslab_min_alloc_size, max_size);
616 offset = metaslab_block_picker(t, extent_end, rsize, 1ULL);
617 if (offset != -1)
618 *cursor = offset + size;
619 } else {
620 offset = metaslab_block_picker(t, cursor, rsize, 1ULL);
621 }
622 ASSERT3U(*cursor, <=, *extent_end);
623 return (offset);
624}
625
626static boolean_t
627metaslab_cdf_fragmented(space_map_t *sm)
628{
629 uint64_t max_size = metaslab_pp_maxsize(sm);
630
631 if (max_size > (metaslab_min_alloc_size * 10))
632 return (B_FALSE);
633 return (B_TRUE);
634}
635
636static space_map_ops_t metaslab_cdf_ops = {
637 metaslab_pp_load,
638 metaslab_pp_unload,
639 metaslab_cdf_alloc,
640 metaslab_pp_claim,
641 metaslab_pp_free,
642 metaslab_pp_maxsize,
643 metaslab_cdf_fragmented
644};
645
646uint64_t metaslab_ndf_clump_shift = 4;
647
648static uint64_t
649metaslab_ndf_alloc(space_map_t *sm, uint64_t size)
650{
651 avl_tree_t *t = &sm->sm_root;
652 avl_index_t where;
653 space_seg_t *ss, ssearch;
654 uint64_t hbit = highbit(size);
655 uint64_t *cursor = (uint64_t *)sm->sm_ppd + hbit - 1;
656 uint64_t max_size = metaslab_pp_maxsize(sm);
657
658 ASSERT(MUTEX_HELD(sm->sm_lock));
659 ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
660
661 if (max_size < size)
662 return (-1ULL);
663
664 ssearch.ss_start = *cursor;
665 ssearch.ss_end = *cursor + size;
666
667 ss = avl_find(t, &ssearch, &where);
668 if (ss == NULL || (ss->ss_start + size > ss->ss_end)) {
669 t = sm->sm_pp_root;
670
671 ssearch.ss_start = 0;
672 ssearch.ss_end = MIN(max_size,
673 1ULL << (hbit + metaslab_ndf_clump_shift));
674 ss = avl_find(t, &ssearch, &where);
675 if (ss == NULL)
676 ss = avl_nearest(t, where, AVL_AFTER);
677 ASSERT(ss != NULL);
678 }
679
680 if (ss != NULL) {
681 if (ss->ss_start + size <= ss->ss_end) {
682 *cursor = ss->ss_start + size;
683 return (ss->ss_start);
684 }
685 }
686 return (-1ULL);
687}
688
689static boolean_t
690metaslab_ndf_fragmented(space_map_t *sm)
691{
692 uint64_t max_size = metaslab_pp_maxsize(sm);
693
694 if (max_size > (metaslab_min_alloc_size << metaslab_ndf_clump_shift))
695 return (B_FALSE);
696 return (B_TRUE);
697}
698
699
700static space_map_ops_t metaslab_ndf_ops = {
701 metaslab_pp_load,
702 metaslab_pp_unload,
703 metaslab_ndf_alloc,
704 metaslab_pp_claim,
705 metaslab_pp_free,
706 metaslab_pp_maxsize,
707 metaslab_ndf_fragmented
708};
709
710space_map_ops_t *zfs_metaslab_ops = &metaslab_df_ops;
711
712/*
713 * ==========================================================================
714 * Metaslabs
715 * ==========================================================================
716 */
717metaslab_t *
718metaslab_init(metaslab_group_t *mg, space_map_obj_t *smo,
719 uint64_t start, uint64_t size, uint64_t txg)
720{
721 vdev_t *vd = mg->mg_vd;
722 metaslab_t *msp;
723
724 msp = kmem_zalloc(sizeof (metaslab_t), KM_SLEEP);
725 mutex_init(&msp->ms_lock, NULL, MUTEX_DEFAULT, NULL);
726
727 msp->ms_smo_syncing = *smo;
728
729 /*
730 * We create the main space map here, but we don't create the
731 * allocmaps and freemaps until metaslab_sync_done(). This serves
732 * two purposes: it allows metaslab_sync_done() to detect the
733 * addition of new space; and for debugging, it ensures that we'd
734 * data fault on any attempt to use this metaslab before it's ready.
735 */
736 space_map_create(&msp->ms_map, start, size,
737 vd->vdev_ashift, &msp->ms_lock);
738
739 metaslab_group_add(mg, msp);
740
741 if (metaslab_debug && smo->smo_object != 0) {
742 mutex_enter(&msp->ms_lock);
743 VERIFY(space_map_load(&msp->ms_map, mg->mg_class->mc_ops,
744 SM_FREE, smo, spa_meta_objset(vd->vdev_spa)) == 0);
745 mutex_exit(&msp->ms_lock);
746 }
747
748 /*
749 * If we're opening an existing pool (txg == 0) or creating
750 * a new one (txg == TXG_INITIAL), all space is available now.
751 * If we're adding space to an existing pool, the new space
752 * does not become available until after this txg has synced.
753 */
754 if (txg <= TXG_INITIAL)
755 metaslab_sync_done(msp, 0);
756
757 if (txg != 0) {
758 vdev_dirty(vd, 0, NULL, txg);
759 vdev_dirty(vd, VDD_METASLAB, msp, txg);
760 }
761
762 return (msp);
763}
764
765void
766metaslab_fini(metaslab_t *msp)
767{
768 metaslab_group_t *mg = msp->ms_group;
769
770 vdev_space_update(mg->mg_vd,
771 -msp->ms_smo.smo_alloc, 0, -msp->ms_map.sm_size);
772
773 metaslab_group_remove(mg, msp);
774
775 mutex_enter(&msp->ms_lock);
776
777 space_map_unload(&msp->ms_map);
778 space_map_destroy(&msp->ms_map);
779
780 for (int t = 0; t < TXG_SIZE; t++) {
781 space_map_destroy(&msp->ms_allocmap[t]);
782 space_map_destroy(&msp->ms_freemap[t]);
783 }
784
785 for (int t = 0; t < TXG_DEFER_SIZE; t++)
786 space_map_destroy(&msp->ms_defermap[t]);
787
788 ASSERT0(msp->ms_deferspace);
789
790 mutex_exit(&msp->ms_lock);
791 mutex_destroy(&msp->ms_lock);
792
793 kmem_free(msp, sizeof (metaslab_t));
794}
795
796#define METASLAB_WEIGHT_PRIMARY (1ULL << 63)
797#define METASLAB_WEIGHT_SECONDARY (1ULL << 62)
798#define METASLAB_ACTIVE_MASK \
799 (METASLAB_WEIGHT_PRIMARY | METASLAB_WEIGHT_SECONDARY)
800
801static uint64_t
802metaslab_weight(metaslab_t *msp)
803{
804 metaslab_group_t *mg = msp->ms_group;
805 space_map_t *sm = &msp->ms_map;
806 space_map_obj_t *smo = &msp->ms_smo;
807 vdev_t *vd = mg->mg_vd;
808 uint64_t weight, space;
809
810 ASSERT(MUTEX_HELD(&msp->ms_lock));
811
812 /*
813 * The baseline weight is the metaslab's free space.
814 */
815 space = sm->sm_size - smo->smo_alloc;
816 weight = space;
817
818 /*
819 * Modern disks have uniform bit density and constant angular velocity.
820 * Therefore, the outer recording zones are faster (higher bandwidth)
821 * than the inner zones by the ratio of outer to inner track diameter,
822 * which is typically around 2:1. We account for this by assigning
823 * higher weight to lower metaslabs (multiplier ranging from 2x to 1x).
824 * In effect, this means that we'll select the metaslab with the most
825 * free bandwidth rather than simply the one with the most free space.
826 */
827 weight = 2 * weight -
828 ((sm->sm_start >> vd->vdev_ms_shift) * weight) / vd->vdev_ms_count;
829 ASSERT(weight >= space && weight <= 2 * space);
830
831 /*
832 * For locality, assign higher weight to metaslabs which have
833 * a lower offset than what we've already activated.
834 */
835 if (sm->sm_start <= mg->mg_bonus_area)
836 weight *= (metaslab_smo_bonus_pct / 100);
837 ASSERT(weight >= space &&
838 weight <= 2 * (metaslab_smo_bonus_pct / 100) * space);
839
840 if (sm->sm_loaded && !sm->sm_ops->smop_fragmented(sm)) {
841 /*
842 * If this metaslab is one we're actively using, adjust its
843 * weight to make it preferable to any inactive metaslab so
844 * we'll polish it off.
845 */
846 weight |= (msp->ms_weight & METASLAB_ACTIVE_MASK);
847 }
848 return (weight);
849}
850
851static void
852metaslab_prefetch(metaslab_group_t *mg)
853{
854 spa_t *spa = mg->mg_vd->vdev_spa;
855 metaslab_t *msp;
856 avl_tree_t *t = &mg->mg_metaslab_tree;
857 int m;
858
859 mutex_enter(&mg->mg_lock);
860
861 /*
862 * Prefetch the next potential metaslabs
863 */
864 for (msp = avl_first(t), m = 0; msp; msp = AVL_NEXT(t, msp), m++) {
865 space_map_t *sm = &msp->ms_map;
866 space_map_obj_t *smo = &msp->ms_smo;
867
868 /* If we have reached our prefetch limit then we're done */
869 if (m >= metaslab_prefetch_limit)
870 break;
871
872 if (!sm->sm_loaded && smo->smo_object != 0) {
873 mutex_exit(&mg->mg_lock);
874 dmu_prefetch(spa_meta_objset(spa), smo->smo_object,
875 0ULL, smo->smo_objsize);
876 mutex_enter(&mg->mg_lock);
877 }
878 }
879 mutex_exit(&mg->mg_lock);
880}
881
882static int
883metaslab_activate(metaslab_t *msp, uint64_t activation_weight)
884{
885 metaslab_group_t *mg = msp->ms_group;
886 space_map_t *sm = &msp->ms_map;
887 space_map_ops_t *sm_ops = msp->ms_group->mg_class->mc_ops;
888
889 ASSERT(MUTEX_HELD(&msp->ms_lock));
890
891 if ((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
892 space_map_load_wait(sm);
893 if (!sm->sm_loaded) {
894 space_map_obj_t *smo = &msp->ms_smo;
895
896 int error = space_map_load(sm, sm_ops, SM_FREE, smo,
897 spa_meta_objset(msp->ms_group->mg_vd->vdev_spa));
898 if (error) {
899 metaslab_group_sort(msp->ms_group, msp, 0);
900 return (error);
901 }
902 for (int t = 0; t < TXG_DEFER_SIZE; t++)
903 space_map_walk(&msp->ms_defermap[t],
904 space_map_claim, sm);
905
906 }
907
908 /*
909 * Track the bonus area as we activate new metaslabs.
910 */
911 if (sm->sm_start > mg->mg_bonus_area) {
912 mutex_enter(&mg->mg_lock);
913 mg->mg_bonus_area = sm->sm_start;
914 mutex_exit(&mg->mg_lock);
915 }
916
917 metaslab_group_sort(msp->ms_group, msp,
918 msp->ms_weight | activation_weight);
919 }
920 ASSERT(sm->sm_loaded);
921 ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK);
922
923 return (0);
924}
925
926static void
927metaslab_passivate(metaslab_t *msp, uint64_t size)
928{
929 /*
930 * If size < SPA_MINBLOCKSIZE, then we will not allocate from
931 * this metaslab again. In that case, it had better be empty,
932 * or we would be leaving space on the table.
933 */
934 ASSERT(size >= SPA_MINBLOCKSIZE || msp->ms_map.sm_space == 0);
935 metaslab_group_sort(msp->ms_group, msp, MIN(msp->ms_weight, size));
936 ASSERT((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0);
937}
938
939/*
940 * Write a metaslab to disk in the context of the specified transaction group.
941 */
942void
943metaslab_sync(metaslab_t *msp, uint64_t txg)
944{
945 vdev_t *vd = msp->ms_group->mg_vd;
946 spa_t *spa = vd->vdev_spa;
947 objset_t *mos = spa_meta_objset(spa);
948 space_map_t *allocmap = &msp->ms_allocmap[txg & TXG_MASK];
949 space_map_t *freemap = &msp->ms_freemap[txg & TXG_MASK];
950 space_map_t *freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
951 space_map_t *sm = &msp->ms_map;
952 space_map_obj_t *smo = &msp->ms_smo_syncing;
953 dmu_buf_t *db;
954 dmu_tx_t *tx;
955
956 ASSERT(!vd->vdev_ishole);
957
958 if (allocmap->sm_space == 0 && freemap->sm_space == 0)
959 return;
960
961 /*
962 * The only state that can actually be changing concurrently with
963 * metaslab_sync() is the metaslab's ms_map. No other thread can
964 * be modifying this txg's allocmap, freemap, freed_map, or smo.
965 * Therefore, we only hold ms_lock to satify space_map ASSERTs.
966 * We drop it whenever we call into the DMU, because the DMU
967 * can call down to us (e.g. via zio_free()) at any time.
968 */
969
970 tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg);
971
972 if (smo->smo_object == 0) {
973 ASSERT(smo->smo_objsize == 0);
974 ASSERT(smo->smo_alloc == 0);
975 smo->smo_object = dmu_object_alloc(mos,
976 DMU_OT_SPACE_MAP, 1 << SPACE_MAP_BLOCKSHIFT,
977 DMU_OT_SPACE_MAP_HEADER, sizeof (*smo), tx);
978 ASSERT(smo->smo_object != 0);
979 dmu_write(mos, vd->vdev_ms_array, sizeof (uint64_t) *
980 (sm->sm_start >> vd->vdev_ms_shift),
981 sizeof (uint64_t), &smo->smo_object, tx);
982 }
983
984 mutex_enter(&msp->ms_lock);
985
986 space_map_walk(freemap, space_map_add, freed_map);
987
988 if (sm->sm_loaded && spa_sync_pass(spa) == 1 && smo->smo_objsize >=
989 2 * sizeof (uint64_t) * avl_numnodes(&sm->sm_root)) {
990 /*
991 * The in-core space map representation is twice as compact
992 * as the on-disk one, so it's time to condense the latter
993 * by generating a pure allocmap from first principles.
994 *
995 * This metaslab is 100% allocated,
996 * minus the content of the in-core map (sm),
997 * minus what's been freed this txg (freed_map),
998 * minus deferred frees (ms_defermap[]),
999 * minus allocations from txgs in the future
1000 * (because they haven't been committed yet).
1001 */
1002 space_map_vacate(allocmap, NULL, NULL);
1003 space_map_vacate(freemap, NULL, NULL);
1004
1005 space_map_add(allocmap, allocmap->sm_start, allocmap->sm_size);
1006
1007 space_map_walk(sm, space_map_remove, allocmap);
1008 space_map_walk(freed_map, space_map_remove, allocmap);
1009
1010 for (int t = 0; t < TXG_DEFER_SIZE; t++)
1011 space_map_walk(&msp->ms_defermap[t],
1012 space_map_remove, allocmap);
1013
1014 for (int t = 1; t < TXG_CONCURRENT_STATES; t++)
1015 space_map_walk(&msp->ms_allocmap[(txg + t) & TXG_MASK],
1016 space_map_remove, allocmap);
1017
1018 mutex_exit(&msp->ms_lock);
1019 space_map_truncate(smo, mos, tx);
1020 mutex_enter(&msp->ms_lock);
1021 }
1022
1023 space_map_sync(allocmap, SM_ALLOC, smo, mos, tx);
1024 space_map_sync(freemap, SM_FREE, smo, mos, tx);
1025
1026 mutex_exit(&msp->ms_lock);
1027
1028 VERIFY(0 == dmu_bonus_hold(mos, smo->smo_object, FTAG, &db));
1029 dmu_buf_will_dirty(db, tx);
1030 ASSERT3U(db->db_size, >=, sizeof (*smo));
1031 bcopy(smo, db->db_data, sizeof (*smo));
1032 dmu_buf_rele(db, FTAG);
1033
1034 dmu_tx_commit(tx);
1035}
1036
1037/*
1038 * Called after a transaction group has completely synced to mark
1039 * all of the metaslab's free space as usable.
1040 */
1041void
1042metaslab_sync_done(metaslab_t *msp, uint64_t txg)
1043{
1044 space_map_obj_t *smo = &msp->ms_smo;
1045 space_map_obj_t *smosync = &msp->ms_smo_syncing;
1046 space_map_t *sm = &msp->ms_map;
1047 space_map_t *freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
1048 space_map_t *defer_map = &msp->ms_defermap[txg % TXG_DEFER_SIZE];
1049 metaslab_group_t *mg = msp->ms_group;
1050 vdev_t *vd = mg->mg_vd;
1051 int64_t alloc_delta, defer_delta;
1052
1053 ASSERT(!vd->vdev_ishole);
1054
1055 mutex_enter(&msp->ms_lock);
1056
1057 /*
1058 * If this metaslab is just becoming available, initialize its
1059 * allocmaps and freemaps and add its capacity to the vdev.
1060 */
1061 if (freed_map->sm_size == 0) {
1062 for (int t = 0; t < TXG_SIZE; t++) {
1063 space_map_create(&msp->ms_allocmap[t], sm->sm_start,
1064 sm->sm_size, sm->sm_shift, sm->sm_lock);
1065 space_map_create(&msp->ms_freemap[t], sm->sm_start,
1066 sm->sm_size, sm->sm_shift, sm->sm_lock);
1067 }
1068
1069 for (int t = 0; t < TXG_DEFER_SIZE; t++)
1070 space_map_create(&msp->ms_defermap[t], sm->sm_start,
1071 sm->sm_size, sm->sm_shift, sm->sm_lock);
1072
1073 vdev_space_update(vd, 0, 0, sm->sm_size);
1074 }
1075
1076 alloc_delta = smosync->smo_alloc - smo->smo_alloc;
1077 defer_delta = freed_map->sm_space - defer_map->sm_space;
1078
1079 vdev_space_update(vd, alloc_delta + defer_delta, defer_delta, 0);
1080
1081 ASSERT(msp->ms_allocmap[txg & TXG_MASK].sm_space == 0);
1082 ASSERT(msp->ms_freemap[txg & TXG_MASK].sm_space == 0);
1083
1084 /*
1085 * If there's a space_map_load() in progress, wait for it to complete
1086 * so that we have a consistent view of the in-core space map.
1087 * Then, add defer_map (oldest deferred frees) to this map and
1088 * transfer freed_map (this txg's frees) to defer_map.
1089 */
1090 space_map_load_wait(sm);
1091 space_map_vacate(defer_map, sm->sm_loaded ? space_map_free : NULL, sm);
1092 space_map_vacate(freed_map, space_map_add, defer_map);
1093
1094 *smo = *smosync;
1095
1096 msp->ms_deferspace += defer_delta;
1097 ASSERT3S(msp->ms_deferspace, >=, 0);
1098 ASSERT3S(msp->ms_deferspace, <=, sm->sm_size);
1099 if (msp->ms_deferspace != 0) {
1100 /*
1101 * Keep syncing this metaslab until all deferred frees
1102 * are back in circulation.
1103 */
1104 vdev_dirty(vd, VDD_METASLAB, msp, txg + 1);
1105 }
1106
1107 /*
1108 * If the map is loaded but no longer active, evict it as soon as all
1109 * future allocations have synced. (If we unloaded it now and then
1110 * loaded a moment later, the map wouldn't reflect those allocations.)
1111 */
1112 if (sm->sm_loaded && (msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
1113 int evictable = 1;
1114
1115 for (int t = 1; t < TXG_CONCURRENT_STATES; t++)
1116 if (msp->ms_allocmap[(txg + t) & TXG_MASK].sm_space)
1117 evictable = 0;
1118
1119 if (evictable && !metaslab_debug)
1120 space_map_unload(sm);
1121 }
1122
1123 metaslab_group_sort(mg, msp, metaslab_weight(msp));
1124
1125 mutex_exit(&msp->ms_lock);
1126}
1127
1128void
1129metaslab_sync_reassess(metaslab_group_t *mg)
1130{
1131 vdev_t *vd = mg->mg_vd;
1132 int64_t failures = mg->mg_alloc_failures;
1133
1134 /*
1135 * Re-evaluate all metaslabs which have lower offsets than the
1136 * bonus area.
1137 */
1138 for (int m = 0; m < vd->vdev_ms_count; m++) {
1139 metaslab_t *msp = vd->vdev_ms[m];
1140
1141 if (msp->ms_map.sm_start > mg->mg_bonus_area)
1142 break;
1143
1144 mutex_enter(&msp->ms_lock);
1145 metaslab_group_sort(mg, msp, metaslab_weight(msp));
1146 mutex_exit(&msp->ms_lock);
1147 }
1148
1149 atomic_add_64(&mg->mg_alloc_failures, -failures);
1150
1151 /*
1152 * Prefetch the next potential metaslabs
1153 */
1154 metaslab_prefetch(mg);
1155}
1156
1157static uint64_t
1158metaslab_distance(metaslab_t *msp, dva_t *dva)
1159{
1160 uint64_t ms_shift = msp->ms_group->mg_vd->vdev_ms_shift;
1161 uint64_t offset = DVA_GET_OFFSET(dva) >> ms_shift;
1162 uint64_t start = msp->ms_map.sm_start >> ms_shift;
1163
1164 if (msp->ms_group->mg_vd->vdev_id != DVA_GET_VDEV(dva))
1165 return (1ULL << 63);
1166
1167 if (offset < start)
1168 return ((start - offset) << ms_shift);
1169 if (offset > start)
1170 return ((offset - start) << ms_shift);
1171 return (0);
1172}
1173
1174static uint64_t
1175metaslab_group_alloc(metaslab_group_t *mg, uint64_t psize, uint64_t asize,
1176 uint64_t txg, uint64_t min_distance, dva_t *dva, int d, int flags)
1177{
1178 spa_t *spa = mg->mg_vd->vdev_spa;
1179 metaslab_t *msp = NULL;
1180 uint64_t offset = -1ULL;
1181 avl_tree_t *t = &mg->mg_metaslab_tree;
1182 uint64_t activation_weight;
1183 uint64_t target_distance;
1184 int i;
1185
1186 activation_weight = METASLAB_WEIGHT_PRIMARY;
1187 for (i = 0; i < d; i++) {
1188 if (DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) {
1189 activation_weight = METASLAB_WEIGHT_SECONDARY;
1190 break;
1191 }
1192 }
1193
1194 for (;;) {
1195 boolean_t was_active;
1196
1197 mutex_enter(&mg->mg_lock);
1198 for (msp = avl_first(t); msp; msp = AVL_NEXT(t, msp)) {
1199 if (msp->ms_weight < asize) {
1200 spa_dbgmsg(spa, "%s: failed to meet weight "
1201 "requirement: vdev %llu, txg %llu, mg %p, "
1202 "msp %p, psize %llu, asize %llu, "
1203 "failures %llu, weight %llu",
1204 spa_name(spa), mg->mg_vd->vdev_id, txg,
1205 mg, msp, psize, asize,
1206 mg->mg_alloc_failures, msp->ms_weight);
1207 mutex_exit(&mg->mg_lock);
1208 return (-1ULL);
1209 }
1210 was_active = msp->ms_weight & METASLAB_ACTIVE_MASK;
1211 if (activation_weight == METASLAB_WEIGHT_PRIMARY)
1212 break;
1213
1214 target_distance = min_distance +
1215 (msp->ms_smo.smo_alloc ? 0 : min_distance >> 1);
1216
1217 for (i = 0; i < d; i++)
1218 if (metaslab_distance(msp, &dva[i]) <
1219 target_distance)
1220 break;
1221 if (i == d)
1222 break;
1223 }
1224 mutex_exit(&mg->mg_lock);
1225 if (msp == NULL)
1226 return (-1ULL);
1227
1228 /*
1229 * If we've already reached the allowable number of failed
1230 * allocation attempts on this metaslab group then we
1231 * consider skipping it. We skip it only if we're allowed
1232 * to "fast" gang, the physical size is larger than
1233 * a gang block, and we're attempting to allocate from
1234 * the primary metaslab.
1235 */
1236 if (mg->mg_alloc_failures > zfs_mg_alloc_failures &&
1237 CAN_FASTGANG(flags) && psize > SPA_GANGBLOCKSIZE &&
1238 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1239 spa_dbgmsg(spa, "%s: skipping metaslab group: "
1240 "vdev %llu, txg %llu, mg %p, psize %llu, "
1241 "asize %llu, failures %llu", spa_name(spa),
1242 mg->mg_vd->vdev_id, txg, mg, psize, asize,
1243 mg->mg_alloc_failures);
1244 return (-1ULL);
1245 }
1246
1247 mutex_enter(&msp->ms_lock);
1248
1249 /*
1250 * Ensure that the metaslab we have selected is still
1251 * capable of handling our request. It's possible that
1252 * another thread may have changed the weight while we
1253 * were blocked on the metaslab lock.
1254 */
1255 if (msp->ms_weight < asize || (was_active &&
1256 !(msp->ms_weight & METASLAB_ACTIVE_MASK) &&
1257 activation_weight == METASLAB_WEIGHT_PRIMARY)) {
1258 mutex_exit(&msp->ms_lock);
1259 continue;
1260 }
1261
1262 if ((msp->ms_weight & METASLAB_WEIGHT_SECONDARY) &&
1263 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1264 metaslab_passivate(msp,
1265 msp->ms_weight & ~METASLAB_ACTIVE_MASK);
1266 mutex_exit(&msp->ms_lock);
1267 continue;
1268 }
1269
1270 if (metaslab_activate(msp, activation_weight) != 0) {
1271 mutex_exit(&msp->ms_lock);
1272 continue;
1273 }
1274
1275 if ((offset = space_map_alloc(&msp->ms_map, asize)) != -1ULL)
1276 break;
1277
1278 atomic_inc_64(&mg->mg_alloc_failures);
1279
1280 metaslab_passivate(msp, space_map_maxsize(&msp->ms_map));
1281
1282 mutex_exit(&msp->ms_lock);
1283 }
1284
1285 if (msp->ms_allocmap[txg & TXG_MASK].sm_space == 0)
1286 vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg);
1287
1288 space_map_add(&msp->ms_allocmap[txg & TXG_MASK], offset, asize);
1289
1290 mutex_exit(&msp->ms_lock);
1291
1292 return (offset);
1293}
1294
1295/*
1296 * Allocate a block for the specified i/o.
1297 */
1298static int
1299metaslab_alloc_dva(spa_t *spa, metaslab_class_t *mc, uint64_t psize,
1300 dva_t *dva, int d, dva_t *hintdva, uint64_t txg, int flags)
1301{
1302 metaslab_group_t *mg, *rotor;
1303 vdev_t *vd;
1304 int dshift = 3;
1305 int all_zero;
1306 int zio_lock = B_FALSE;
1307 boolean_t allocatable;
1308 uint64_t offset = -1ULL;
1309 uint64_t asize;
1310 uint64_t distance;
1311
1312 ASSERT(!DVA_IS_VALID(&dva[d]));
1313
1314 /*
1315 * For testing, make some blocks above a certain size be gang blocks.
1316 */
1317 if (psize >= metaslab_gang_bang && (ddi_get_lbolt() & 3) == 0)
1318 return (ENOSPC);
1319
1320 /*
1321 * Start at the rotor and loop through all mgs until we find something.
1322 * Note that there's no locking on mc_rotor or mc_aliquot because
1323 * nothing actually breaks if we miss a few updates -- we just won't
1324 * allocate quite as evenly. It all balances out over time.
1325 *
1326 * If we are doing ditto or log blocks, try to spread them across
1327 * consecutive vdevs. If we're forced to reuse a vdev before we've
1328 * allocated all of our ditto blocks, then try and spread them out on
1329 * that vdev as much as possible. If it turns out to not be possible,
1330 * gradually lower our standards until anything becomes acceptable.
1331 * Also, allocating on consecutive vdevs (as opposed to random vdevs)
1332 * gives us hope of containing our fault domains to something we're
1333 * able to reason about. Otherwise, any two top-level vdev failures
1334 * will guarantee the loss of data. With consecutive allocation,
1335 * only two adjacent top-level vdev failures will result in data loss.
1336 *
1337 * If we are doing gang blocks (hintdva is non-NULL), try to keep
1338 * ourselves on the same vdev as our gang block header. That
1339 * way, we can hope for locality in vdev_cache, plus it makes our
1340 * fault domains something tractable.
1341 */
1342 if (hintdva) {
1343 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&hintdva[d]));
1344
1345 /*
1346 * It's possible the vdev we're using as the hint no
1347 * longer exists (i.e. removed). Consult the rotor when
1348 * all else fails.
1349 */
1350 if (vd != NULL) {
1351 mg = vd->vdev_mg;
1352
1353 if (flags & METASLAB_HINTBP_AVOID &&
1354 mg->mg_next != NULL)
1355 mg = mg->mg_next;
1356 } else {
1357 mg = mc->mc_rotor;
1358 }
1359 } else if (d != 0) {
1360 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[d - 1]));
1361 mg = vd->vdev_mg->mg_next;
1362 } else {
1363 mg = mc->mc_rotor;
1364 }
1365
1366 /*
1367 * If the hint put us into the wrong metaslab class, or into a
1368 * metaslab group that has been passivated, just follow the rotor.
1369 */
1370 if (mg->mg_class != mc || mg->mg_activation_count <= 0)
1371 mg = mc->mc_rotor;
1372
1373 rotor = mg;
1374top:
1375 all_zero = B_TRUE;
1376 do {
1377 ASSERT(mg->mg_activation_count == 1);
1378
1379 vd = mg->mg_vd;
1380
1381 /*
1382 * Don't allocate from faulted devices.
1383 */
1384 if (zio_lock) {
1385 spa_config_enter(spa, SCL_ZIO, FTAG, RW_READER);
1386 allocatable = vdev_allocatable(vd);
1387 spa_config_exit(spa, SCL_ZIO, FTAG);
1388 } else {
1389 allocatable = vdev_allocatable(vd);
1390 }
1391 if (!allocatable)
1392 goto next;
1393
1394 /*
1395 * Avoid writing single-copy data to a failing vdev
|
1390 all_zero = B_FALSE;
1391 goto next;
1392 }
1393
1394 ASSERT(mg->mg_class == mc);
1395
1396 distance = vd->vdev_asize >> dshift;
1397 if (distance <= (1ULL << vd->vdev_ms_shift))
1398 distance = 0;
1399 else
1400 all_zero = B_FALSE;
1401
1402 asize = vdev_psize_to_asize(vd, psize);
1403 ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0);
1404
1405 offset = metaslab_group_alloc(mg, psize, asize, txg, distance,
1406 dva, d, flags);
1407 if (offset != -1ULL) {
1408 /*
1409 * If we've just selected this metaslab group,
1410 * figure out whether the corresponding vdev is
1411 * over- or under-used relative to the pool,
1412 * and set an allocation bias to even it out.
1413 */
1414 if (mc->mc_aliquot == 0) {
1415 vdev_stat_t *vs = &vd->vdev_stat;
1416 int64_t vu, cu;
1417
1418 vu = (vs->vs_alloc * 100) / (vs->vs_space + 1);
1419 cu = (mc->mc_alloc * 100) / (mc->mc_space + 1);
1420
1421 /*
1422 * Calculate how much more or less we should
1423 * try to allocate from this device during
1424 * this iteration around the rotor.
1425 * For example, if a device is 80% full
1426 * and the pool is 20% full then we should
1427 * reduce allocations by 60% on this device.
1428 *
1429 * mg_bias = (20 - 80) * 512K / 100 = -307K
1430 *
1431 * This reduces allocations by 307K for this
1432 * iteration.
1433 */
1434 mg->mg_bias = ((cu - vu) *
1435 (int64_t)mg->mg_aliquot) / 100;
1436 }
1437
1438 if (atomic_add_64_nv(&mc->mc_aliquot, asize) >=
1439 mg->mg_aliquot + mg->mg_bias) {
1440 mc->mc_rotor = mg->mg_next;
1441 mc->mc_aliquot = 0;
1442 }
1443
1444 DVA_SET_VDEV(&dva[d], vd->vdev_id);
1445 DVA_SET_OFFSET(&dva[d], offset);
1446 DVA_SET_GANG(&dva[d], !!(flags & METASLAB_GANG_HEADER));
1447 DVA_SET_ASIZE(&dva[d], asize);
1448
1449 return (0);
1450 }
1451next:
1452 mc->mc_rotor = mg->mg_next;
1453 mc->mc_aliquot = 0;
1454 } while ((mg = mg->mg_next) != rotor);
1455
1456 if (!all_zero) {
1457 dshift++;
1458 ASSERT(dshift < 64);
1459 goto top;
1460 }
1461
1462 if (!allocatable && !zio_lock) {
1463 dshift = 3;
1464 zio_lock = B_TRUE;
1465 goto top;
1466 }
1467
1468 bzero(&dva[d], sizeof (dva_t));
1469
1470 return (ENOSPC);
1471}
1472
1473/*
1474 * Free the block represented by DVA in the context of the specified
1475 * transaction group.
1476 */
1477static void
1478metaslab_free_dva(spa_t *spa, const dva_t *dva, uint64_t txg, boolean_t now)
1479{
1480 uint64_t vdev = DVA_GET_VDEV(dva);
1481 uint64_t offset = DVA_GET_OFFSET(dva);
1482 uint64_t size = DVA_GET_ASIZE(dva);
1483 vdev_t *vd;
1484 metaslab_t *msp;
1485
1486 ASSERT(DVA_IS_VALID(dva));
1487
1488 if (txg > spa_freeze_txg(spa))
1489 return;
1490
1491 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
1492 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count) {
1493 cmn_err(CE_WARN, "metaslab_free_dva(): bad DVA %llu:%llu",
1494 (u_longlong_t)vdev, (u_longlong_t)offset);
1495 ASSERT(0);
1496 return;
1497 }
1498
1499 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
1500
1501 if (DVA_GET_GANG(dva))
1502 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
1503
1504 mutex_enter(&msp->ms_lock);
1505
1506 if (now) {
1507 space_map_remove(&msp->ms_allocmap[txg & TXG_MASK],
1508 offset, size);
1509 space_map_free(&msp->ms_map, offset, size);
1510 } else {
1511 if (msp->ms_freemap[txg & TXG_MASK].sm_space == 0)
1512 vdev_dirty(vd, VDD_METASLAB, msp, txg);
1513 space_map_add(&msp->ms_freemap[txg & TXG_MASK], offset, size);
1514 }
1515
1516 mutex_exit(&msp->ms_lock);
1517}
1518
1519/*
1520 * Intent log support: upon opening the pool after a crash, notify the SPA
1521 * of blocks that the intent log has allocated for immediate write, but
1522 * which are still considered free by the SPA because the last transaction
1523 * group didn't commit yet.
1524 */
1525static int
1526metaslab_claim_dva(spa_t *spa, const dva_t *dva, uint64_t txg)
1527{
1528 uint64_t vdev = DVA_GET_VDEV(dva);
1529 uint64_t offset = DVA_GET_OFFSET(dva);
1530 uint64_t size = DVA_GET_ASIZE(dva);
1531 vdev_t *vd;
1532 metaslab_t *msp;
1533 int error = 0;
1534
1535 ASSERT(DVA_IS_VALID(dva));
1536
1537 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
1538 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count)
1539 return (ENXIO);
1540
1541 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
1542
1543 if (DVA_GET_GANG(dva))
1544 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
1545
1546 mutex_enter(&msp->ms_lock);
1547
1548 if ((txg != 0 && spa_writeable(spa)) || !msp->ms_map.sm_loaded)
1549 error = metaslab_activate(msp, METASLAB_WEIGHT_SECONDARY);
1550
1551 if (error == 0 && !space_map_contains(&msp->ms_map, offset, size))
1552 error = ENOENT;
1553
1554 if (error || txg == 0) { /* txg == 0 indicates dry run */
1555 mutex_exit(&msp->ms_lock);
1556 return (error);
1557 }
1558
1559 space_map_claim(&msp->ms_map, offset, size);
1560
1561 if (spa_writeable(spa)) { /* don't dirty if we're zdb(1M) */
1562 if (msp->ms_allocmap[txg & TXG_MASK].sm_space == 0)
1563 vdev_dirty(vd, VDD_METASLAB, msp, txg);
1564 space_map_add(&msp->ms_allocmap[txg & TXG_MASK], offset, size);
1565 }
1566
1567 mutex_exit(&msp->ms_lock);
1568
1569 return (0);
1570}
1571
1572int
1573metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp,
1574 int ndvas, uint64_t txg, blkptr_t *hintbp, int flags)
1575{
1576 dva_t *dva = bp->blk_dva;
1577 dva_t *hintdva = hintbp->blk_dva;
1578 int error = 0;
1579
1580 ASSERT(bp->blk_birth == 0);
1581 ASSERT(BP_PHYSICAL_BIRTH(bp) == 0);
1582
1583 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
1584
1585 if (mc->mc_rotor == NULL) { /* no vdevs in this class */
1586 spa_config_exit(spa, SCL_ALLOC, FTAG);
1587 return (ENOSPC);
1588 }
1589
1590 ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa));
1591 ASSERT(BP_GET_NDVAS(bp) == 0);
1592 ASSERT(hintbp == NULL || ndvas <= BP_GET_NDVAS(hintbp));
1593
1594 for (int d = 0; d < ndvas; d++) {
1595 error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva,
1596 txg, flags);
1597 if (error) {
1598 for (d--; d >= 0; d--) {
1599 metaslab_free_dva(spa, &dva[d], txg, B_TRUE);
1600 bzero(&dva[d], sizeof (dva_t));
1601 }
1602 spa_config_exit(spa, SCL_ALLOC, FTAG);
1603 return (error);
1604 }
1605 }
1606 ASSERT(error == 0);
1607 ASSERT(BP_GET_NDVAS(bp) == ndvas);
1608
1609 spa_config_exit(spa, SCL_ALLOC, FTAG);
1610
1611 BP_SET_BIRTH(bp, txg, txg);
1612
1613 return (0);
1614}
1615
1616void
1617metaslab_free(spa_t *spa, const blkptr_t *bp, uint64_t txg, boolean_t now)
1618{
1619 const dva_t *dva = bp->blk_dva;
1620 int ndvas = BP_GET_NDVAS(bp);
1621
1622 ASSERT(!BP_IS_HOLE(bp));
1623 ASSERT(!now || bp->blk_birth >= spa_syncing_txg(spa));
1624
1625 spa_config_enter(spa, SCL_FREE, FTAG, RW_READER);
1626
1627 for (int d = 0; d < ndvas; d++)
1628 metaslab_free_dva(spa, &dva[d], txg, now);
1629
1630 spa_config_exit(spa, SCL_FREE, FTAG);
1631}
1632
1633int
1634metaslab_claim(spa_t *spa, const blkptr_t *bp, uint64_t txg)
1635{
1636 const dva_t *dva = bp->blk_dva;
1637 int ndvas = BP_GET_NDVAS(bp);
1638 int error = 0;
1639
1640 ASSERT(!BP_IS_HOLE(bp));
1641
1642 if (txg != 0) {
1643 /*
1644 * First do a dry run to make sure all DVAs are claimable,
1645 * so we don't have to unwind from partial failures below.
1646 */
1647 if ((error = metaslab_claim(spa, bp, 0)) != 0)
1648 return (error);
1649 }
1650
1651 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
1652
1653 for (int d = 0; d < ndvas; d++)
1654 if ((error = metaslab_claim_dva(spa, &dva[d], txg)) != 0)
1655 break;
1656
1657 spa_config_exit(spa, SCL_ALLOC, FTAG);
1658
1659 ASSERT(error == 0 || txg == 0);
1660
1661 return (error);
1662}
| 1403 all_zero = B_FALSE;
1404 goto next;
1405 }
1406
1407 ASSERT(mg->mg_class == mc);
1408
1409 distance = vd->vdev_asize >> dshift;
1410 if (distance <= (1ULL << vd->vdev_ms_shift))
1411 distance = 0;
1412 else
1413 all_zero = B_FALSE;
1414
1415 asize = vdev_psize_to_asize(vd, psize);
1416 ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0);
1417
1418 offset = metaslab_group_alloc(mg, psize, asize, txg, distance,
1419 dva, d, flags);
1420 if (offset != -1ULL) {
1421 /*
1422 * If we've just selected this metaslab group,
1423 * figure out whether the corresponding vdev is
1424 * over- or under-used relative to the pool,
1425 * and set an allocation bias to even it out.
1426 */
1427 if (mc->mc_aliquot == 0) {
1428 vdev_stat_t *vs = &vd->vdev_stat;
1429 int64_t vu, cu;
1430
1431 vu = (vs->vs_alloc * 100) / (vs->vs_space + 1);
1432 cu = (mc->mc_alloc * 100) / (mc->mc_space + 1);
1433
1434 /*
1435 * Calculate how much more or less we should
1436 * try to allocate from this device during
1437 * this iteration around the rotor.
1438 * For example, if a device is 80% full
1439 * and the pool is 20% full then we should
1440 * reduce allocations by 60% on this device.
1441 *
1442 * mg_bias = (20 - 80) * 512K / 100 = -307K
1443 *
1444 * This reduces allocations by 307K for this
1445 * iteration.
1446 */
1447 mg->mg_bias = ((cu - vu) *
1448 (int64_t)mg->mg_aliquot) / 100;
1449 }
1450
1451 if (atomic_add_64_nv(&mc->mc_aliquot, asize) >=
1452 mg->mg_aliquot + mg->mg_bias) {
1453 mc->mc_rotor = mg->mg_next;
1454 mc->mc_aliquot = 0;
1455 }
1456
1457 DVA_SET_VDEV(&dva[d], vd->vdev_id);
1458 DVA_SET_OFFSET(&dva[d], offset);
1459 DVA_SET_GANG(&dva[d], !!(flags & METASLAB_GANG_HEADER));
1460 DVA_SET_ASIZE(&dva[d], asize);
1461
1462 return (0);
1463 }
1464next:
1465 mc->mc_rotor = mg->mg_next;
1466 mc->mc_aliquot = 0;
1467 } while ((mg = mg->mg_next) != rotor);
1468
1469 if (!all_zero) {
1470 dshift++;
1471 ASSERT(dshift < 64);
1472 goto top;
1473 }
1474
1475 if (!allocatable && !zio_lock) {
1476 dshift = 3;
1477 zio_lock = B_TRUE;
1478 goto top;
1479 }
1480
1481 bzero(&dva[d], sizeof (dva_t));
1482
1483 return (ENOSPC);
1484}
1485
1486/*
1487 * Free the block represented by DVA in the context of the specified
1488 * transaction group.
1489 */
1490static void
1491metaslab_free_dva(spa_t *spa, const dva_t *dva, uint64_t txg, boolean_t now)
1492{
1493 uint64_t vdev = DVA_GET_VDEV(dva);
1494 uint64_t offset = DVA_GET_OFFSET(dva);
1495 uint64_t size = DVA_GET_ASIZE(dva);
1496 vdev_t *vd;
1497 metaslab_t *msp;
1498
1499 ASSERT(DVA_IS_VALID(dva));
1500
1501 if (txg > spa_freeze_txg(spa))
1502 return;
1503
1504 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
1505 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count) {
1506 cmn_err(CE_WARN, "metaslab_free_dva(): bad DVA %llu:%llu",
1507 (u_longlong_t)vdev, (u_longlong_t)offset);
1508 ASSERT(0);
1509 return;
1510 }
1511
1512 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
1513
1514 if (DVA_GET_GANG(dva))
1515 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
1516
1517 mutex_enter(&msp->ms_lock);
1518
1519 if (now) {
1520 space_map_remove(&msp->ms_allocmap[txg & TXG_MASK],
1521 offset, size);
1522 space_map_free(&msp->ms_map, offset, size);
1523 } else {
1524 if (msp->ms_freemap[txg & TXG_MASK].sm_space == 0)
1525 vdev_dirty(vd, VDD_METASLAB, msp, txg);
1526 space_map_add(&msp->ms_freemap[txg & TXG_MASK], offset, size);
1527 }
1528
1529 mutex_exit(&msp->ms_lock);
1530}
1531
1532/*
1533 * Intent log support: upon opening the pool after a crash, notify the SPA
1534 * of blocks that the intent log has allocated for immediate write, but
1535 * which are still considered free by the SPA because the last transaction
1536 * group didn't commit yet.
1537 */
1538static int
1539metaslab_claim_dva(spa_t *spa, const dva_t *dva, uint64_t txg)
1540{
1541 uint64_t vdev = DVA_GET_VDEV(dva);
1542 uint64_t offset = DVA_GET_OFFSET(dva);
1543 uint64_t size = DVA_GET_ASIZE(dva);
1544 vdev_t *vd;
1545 metaslab_t *msp;
1546 int error = 0;
1547
1548 ASSERT(DVA_IS_VALID(dva));
1549
1550 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
1551 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count)
1552 return (ENXIO);
1553
1554 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
1555
1556 if (DVA_GET_GANG(dva))
1557 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
1558
1559 mutex_enter(&msp->ms_lock);
1560
1561 if ((txg != 0 && spa_writeable(spa)) || !msp->ms_map.sm_loaded)
1562 error = metaslab_activate(msp, METASLAB_WEIGHT_SECONDARY);
1563
1564 if (error == 0 && !space_map_contains(&msp->ms_map, offset, size))
1565 error = ENOENT;
1566
1567 if (error || txg == 0) { /* txg == 0 indicates dry run */
1568 mutex_exit(&msp->ms_lock);
1569 return (error);
1570 }
1571
1572 space_map_claim(&msp->ms_map, offset, size);
1573
1574 if (spa_writeable(spa)) { /* don't dirty if we're zdb(1M) */
1575 if (msp->ms_allocmap[txg & TXG_MASK].sm_space == 0)
1576 vdev_dirty(vd, VDD_METASLAB, msp, txg);
1577 space_map_add(&msp->ms_allocmap[txg & TXG_MASK], offset, size);
1578 }
1579
1580 mutex_exit(&msp->ms_lock);
1581
1582 return (0);
1583}
1584
1585int
1586metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp,
1587 int ndvas, uint64_t txg, blkptr_t *hintbp, int flags)
1588{
1589 dva_t *dva = bp->blk_dva;
1590 dva_t *hintdva = hintbp->blk_dva;
1591 int error = 0;
1592
1593 ASSERT(bp->blk_birth == 0);
1594 ASSERT(BP_PHYSICAL_BIRTH(bp) == 0);
1595
1596 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
1597
1598 if (mc->mc_rotor == NULL) { /* no vdevs in this class */
1599 spa_config_exit(spa, SCL_ALLOC, FTAG);
1600 return (ENOSPC);
1601 }
1602
1603 ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa));
1604 ASSERT(BP_GET_NDVAS(bp) == 0);
1605 ASSERT(hintbp == NULL || ndvas <= BP_GET_NDVAS(hintbp));
1606
1607 for (int d = 0; d < ndvas; d++) {
1608 error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva,
1609 txg, flags);
1610 if (error) {
1611 for (d--; d >= 0; d--) {
1612 metaslab_free_dva(spa, &dva[d], txg, B_TRUE);
1613 bzero(&dva[d], sizeof (dva_t));
1614 }
1615 spa_config_exit(spa, SCL_ALLOC, FTAG);
1616 return (error);
1617 }
1618 }
1619 ASSERT(error == 0);
1620 ASSERT(BP_GET_NDVAS(bp) == ndvas);
1621
1622 spa_config_exit(spa, SCL_ALLOC, FTAG);
1623
1624 BP_SET_BIRTH(bp, txg, txg);
1625
1626 return (0);
1627}
1628
1629void
1630metaslab_free(spa_t *spa, const blkptr_t *bp, uint64_t txg, boolean_t now)
1631{
1632 const dva_t *dva = bp->blk_dva;
1633 int ndvas = BP_GET_NDVAS(bp);
1634
1635 ASSERT(!BP_IS_HOLE(bp));
1636 ASSERT(!now || bp->blk_birth >= spa_syncing_txg(spa));
1637
1638 spa_config_enter(spa, SCL_FREE, FTAG, RW_READER);
1639
1640 for (int d = 0; d < ndvas; d++)
1641 metaslab_free_dva(spa, &dva[d], txg, now);
1642
1643 spa_config_exit(spa, SCL_FREE, FTAG);
1644}
1645
1646int
1647metaslab_claim(spa_t *spa, const blkptr_t *bp, uint64_t txg)
1648{
1649 const dva_t *dva = bp->blk_dva;
1650 int ndvas = BP_GET_NDVAS(bp);
1651 int error = 0;
1652
1653 ASSERT(!BP_IS_HOLE(bp));
1654
1655 if (txg != 0) {
1656 /*
1657 * First do a dry run to make sure all DVAs are claimable,
1658 * so we don't have to unwind from partial failures below.
1659 */
1660 if ((error = metaslab_claim(spa, bp, 0)) != 0)
1661 return (error);
1662 }
1663
1664 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
1665
1666 for (int d = 0; d < ndvas; d++)
1667 if ((error = metaslab_claim_dva(spa, &dva[d], txg)) != 0)
1668 break;
1669
1670 spa_config_exit(spa, SCL_ALLOC, FTAG);
1671
1672 ASSERT(error == 0 || txg == 0);
1673
1674 return (error);
1675}
|