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.
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.
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]
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.
27 #include <sys/zfs_context.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>
34 #include <sys/spa_impl.h>
36 SYSCTL_DECL(_vfs_zfs);
37 SYSCTL_NODE(_vfs_zfs, OID_AUTO, metaslab, CTLFLAG_RW, 0, "ZFS metaslab");
40 * Allow allocations to switch to gang blocks quickly. We do this to
41 * avoid having to load lots of space_maps in a given txg. There are,
42 * however, some cases where we want to avoid "fast" ganging and instead
43 * we want to do an exhaustive search of all metaslabs on this device.
44 * Currently we don't allow any gang, zil, or dump device related allocations
47 #define CAN_FASTGANG(flags) \
48 (!((flags) & (METASLAB_GANG_CHILD | METASLAB_GANG_HEADER | \
49 METASLAB_GANG_AVOID)))
51 #define METASLAB_WEIGHT_PRIMARY (1ULL << 63)
52 #define METASLAB_WEIGHT_SECONDARY (1ULL << 62)
53 #define METASLAB_ACTIVE_MASK \
54 (METASLAB_WEIGHT_PRIMARY | METASLAB_WEIGHT_SECONDARY)
56 uint64_t metaslab_aliquot = 512ULL << 10;
57 uint64_t metaslab_gang_bang = SPA_MAXBLOCKSIZE + 1; /* force gang blocks */
58 TUNABLE_QUAD("vfs.zfs.metaslab.gang_bang", &metaslab_gang_bang);
59 SYSCTL_QUAD(_vfs_zfs_metaslab, OID_AUTO, gang_bang, CTLFLAG_RWTUN,
60 &metaslab_gang_bang, 0,
61 "Force gang block allocation for blocks larger than or equal to this value");
64 * The in-core space map representation is more compact than its on-disk form.
65 * The zfs_condense_pct determines how much more compact the in-core
66 * space_map representation must be before we compact it on-disk.
67 * Values should be greater than or equal to 100.
69 int zfs_condense_pct = 200;
70 TUNABLE_INT("vfs.zfs.condense_pct", &zfs_condense_pct);
71 SYSCTL_INT(_vfs_zfs, OID_AUTO, condense_pct, CTLFLAG_RWTUN,
73 "Condense on-disk spacemap when it is more than this many percents"
74 " of in-memory counterpart");
77 * This value defines the number of allowed allocation failures per vdev.
78 * If a device reaches this threshold in a given txg then we consider skipping
79 * allocations on that device. The value of zfs_mg_alloc_failures is computed
80 * in zio_init() unless it has been overridden in /etc/system.
82 int zfs_mg_alloc_failures = 0;
83 TUNABLE_INT("vfs.zfs.mg_alloc_failures", &zfs_mg_alloc_failures);
84 SYSCTL_INT(_vfs_zfs, OID_AUTO, mg_alloc_failures, CTLFLAG_RWTUN,
85 &zfs_mg_alloc_failures, 0,
86 "Number of allowed allocation failures per vdev");
89 * The zfs_mg_noalloc_threshold defines which metaslab groups should
90 * be eligible for allocation. The value is defined as a percentage of
91 * a free space. Metaslab groups that have more free space than
92 * zfs_mg_noalloc_threshold are always eligible for allocations. Once
93 * a metaslab group's free space is less than or equal to the
94 * zfs_mg_noalloc_threshold the allocator will avoid allocating to that
95 * group unless all groups in the pool have reached zfs_mg_noalloc_threshold.
96 * Once all groups in the pool reach zfs_mg_noalloc_threshold then all
97 * groups are allowed to accept allocations. Gang blocks are always
98 * eligible to allocate on any metaslab group. The default value of 0 means
99 * no metaslab group will be excluded based on this criterion.
101 int zfs_mg_noalloc_threshold = 0;
102 TUNABLE_INT("vfs.zfs.mg_noalloc_threshold", &zfs_mg_noalloc_threshold);
103 SYSCTL_INT(_vfs_zfs, OID_AUTO, mg_noalloc_threshold, CTLFLAG_RWTUN,
104 &zfs_mg_noalloc_threshold, 0,
105 "Percentage of metaslab group size that should be free"
106 " to make it eligible for allocation");
109 * When set will load all metaslabs when pool is first opened.
111 int metaslab_debug_load = 0;
112 TUNABLE_INT("vfs.zfs.metaslab.debug_load", &metaslab_debug_load);
113 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, debug_load, CTLFLAG_RWTUN,
114 &metaslab_debug_load, 0,
115 "Load all metaslabs when pool is first opened");
118 * When set will prevent metaslabs from being unloaded.
120 int metaslab_debug_unload = 0;
121 TUNABLE_INT("vfs.zfs.metaslab.debug_unload", &metaslab_debug_unload);
122 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, debug_unload, CTLFLAG_RWTUN,
123 &metaslab_debug_unload, 0,
124 "Prevent metaslabs from being unloaded");
127 * Minimum size which forces the dynamic allocator to change
128 * it's allocation strategy. Once the space map cannot satisfy
129 * an allocation of this size then it switches to using more
130 * aggressive strategy (i.e search by size rather than offset).
132 uint64_t metaslab_df_alloc_threshold = SPA_MAXBLOCKSIZE;
133 TUNABLE_QUAD("vfs.zfs.metaslab.df_alloc_threshold",
134 &metaslab_df_alloc_threshold);
135 SYSCTL_QUAD(_vfs_zfs_metaslab, OID_AUTO, df_alloc_threshold, CTLFLAG_RWTUN,
136 &metaslab_df_alloc_threshold, 0,
137 "Minimum size which forces the dynamic allocator to change it's allocation strategy");
140 * The minimum free space, in percent, which must be available
141 * in a space map to continue allocations in a first-fit fashion.
142 * Once the space_map's free space drops below this level we dynamically
143 * switch to using best-fit allocations.
145 int metaslab_df_free_pct = 4;
146 TUNABLE_INT("vfs.zfs.metaslab.df_free_pct", &metaslab_df_free_pct);
147 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, df_free_pct, CTLFLAG_RWTUN,
148 &metaslab_df_free_pct, 0,
149 "The minimum free space, in percent, which must be available in a space map to continue allocations in a first-fit fashion");
152 * A metaslab is considered "free" if it contains a contiguous
153 * segment which is greater than metaslab_min_alloc_size.
155 uint64_t metaslab_min_alloc_size = DMU_MAX_ACCESS;
156 TUNABLE_QUAD("vfs.zfs.metaslab.min_alloc_size",
157 &metaslab_min_alloc_size);
158 SYSCTL_QUAD(_vfs_zfs_metaslab, OID_AUTO, min_alloc_size, CTLFLAG_RWTUN,
159 &metaslab_min_alloc_size, 0,
160 "A metaslab is considered \"free\" if it contains a contiguous segment which is greater than vfs.zfs.metaslab.min_alloc_size");
163 * Percentage of all cpus that can be used by the metaslab taskq.
165 int metaslab_load_pct = 50;
166 TUNABLE_INT("vfs.zfs.metaslab.load_pct", &metaslab_load_pct);
167 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, load_pct, CTLFLAG_RWTUN,
168 &metaslab_load_pct, 0,
169 "Percentage of cpus that can be used by the metaslab taskq");
172 * Determines how many txgs a metaslab may remain loaded without having any
173 * allocations from it. As long as a metaslab continues to be used we will
176 int metaslab_unload_delay = TXG_SIZE * 2;
177 TUNABLE_INT("vfs.zfs.metaslab.unload_delay", &metaslab_unload_delay);
178 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, unload_delay, CTLFLAG_RWTUN,
179 &metaslab_unload_delay, 0,
180 "Number of TXGs that an unused metaslab can be kept in memory");
183 * Should we be willing to write data to degraded vdevs?
185 boolean_t zfs_write_to_degraded = B_FALSE;
186 SYSCTL_INT(_vfs_zfs, OID_AUTO, write_to_degraded, CTLFLAG_RWTUN,
187 &zfs_write_to_degraded, 0, "Allow writing data to degraded vdevs");
188 TUNABLE_INT("vfs.zfs.write_to_degraded", &zfs_write_to_degraded);
191 * Max number of metaslabs per group to preload.
193 int metaslab_preload_limit = SPA_DVAS_PER_BP;
194 TUNABLE_INT("vfs.zfs.metaslab.preload_limit", &metaslab_preload_limit);
195 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, preload_limit, CTLFLAG_RWTUN,
196 &metaslab_preload_limit, 0,
197 "Max number of metaslabs per group to preload");
200 * Enable/disable preloading of metaslab.
202 boolean_t metaslab_preload_enabled = B_TRUE;
203 TUNABLE_INT("vfs.zfs.metaslab.preload_enabled", &metaslab_preload_enabled);
204 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, preload_enabled, CTLFLAG_RWTUN,
205 &metaslab_preload_enabled, 0,
206 "Max number of metaslabs per group to preload");
209 * Enable/disable additional weight factor for each metaslab.
211 boolean_t metaslab_weight_factor_enable = B_FALSE;
212 TUNABLE_INT("vfs.zfs.metaslab.weight_factor_enable",
213 &metaslab_weight_factor_enable);
214 SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, weight_factor_enable, CTLFLAG_RWTUN,
215 &metaslab_weight_factor_enable, 0,
216 "Enable additional weight factor for each metaslab");
220 * ==========================================================================
222 * ==========================================================================
225 metaslab_class_create(spa_t *spa, metaslab_ops_t *ops)
227 metaslab_class_t *mc;
229 mc = kmem_zalloc(sizeof (metaslab_class_t), KM_SLEEP);
239 metaslab_class_destroy(metaslab_class_t *mc)
241 ASSERT(mc->mc_rotor == NULL);
242 ASSERT(mc->mc_alloc == 0);
243 ASSERT(mc->mc_deferred == 0);
244 ASSERT(mc->mc_space == 0);
245 ASSERT(mc->mc_dspace == 0);
247 kmem_free(mc, sizeof (metaslab_class_t));
251 metaslab_class_validate(metaslab_class_t *mc)
253 metaslab_group_t *mg;
257 * Must hold one of the spa_config locks.
259 ASSERT(spa_config_held(mc->mc_spa, SCL_ALL, RW_READER) ||
260 spa_config_held(mc->mc_spa, SCL_ALL, RW_WRITER));
262 if ((mg = mc->mc_rotor) == NULL)
267 ASSERT(vd->vdev_mg != NULL);
268 ASSERT3P(vd->vdev_top, ==, vd);
269 ASSERT3P(mg->mg_class, ==, mc);
270 ASSERT3P(vd->vdev_ops, !=, &vdev_hole_ops);
271 } while ((mg = mg->mg_next) != mc->mc_rotor);
277 metaslab_class_space_update(metaslab_class_t *mc, int64_t alloc_delta,
278 int64_t defer_delta, int64_t space_delta, int64_t dspace_delta)
280 atomic_add_64(&mc->mc_alloc, alloc_delta);
281 atomic_add_64(&mc->mc_deferred, defer_delta);
282 atomic_add_64(&mc->mc_space, space_delta);
283 atomic_add_64(&mc->mc_dspace, dspace_delta);
287 metaslab_class_minblocksize_update(metaslab_class_t *mc)
289 metaslab_group_t *mg;
291 uint64_t minashift = UINT64_MAX;
293 if ((mg = mc->mc_rotor) == NULL) {
294 mc->mc_minblocksize = SPA_MINBLOCKSIZE;
300 if (vd->vdev_ashift < minashift)
301 minashift = vd->vdev_ashift;
302 } while ((mg = mg->mg_next) != mc->mc_rotor);
304 mc->mc_minblocksize = 1ULL << minashift;
308 metaslab_class_get_alloc(metaslab_class_t *mc)
310 return (mc->mc_alloc);
314 metaslab_class_get_deferred(metaslab_class_t *mc)
316 return (mc->mc_deferred);
320 metaslab_class_get_space(metaslab_class_t *mc)
322 return (mc->mc_space);
326 metaslab_class_get_dspace(metaslab_class_t *mc)
328 return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space);
332 metaslab_class_get_minblocksize(metaslab_class_t *mc)
334 return (mc->mc_minblocksize);
338 * ==========================================================================
340 * ==========================================================================
343 metaslab_compare(const void *x1, const void *x2)
345 const metaslab_t *m1 = x1;
346 const metaslab_t *m2 = x2;
348 if (m1->ms_weight < m2->ms_weight)
350 if (m1->ms_weight > m2->ms_weight)
354 * If the weights are identical, use the offset to force uniqueness.
356 if (m1->ms_start < m2->ms_start)
358 if (m1->ms_start > m2->ms_start)
361 ASSERT3P(m1, ==, m2);
367 * Update the allocatable flag and the metaslab group's capacity.
368 * The allocatable flag is set to true if the capacity is below
369 * the zfs_mg_noalloc_threshold. If a metaslab group transitions
370 * from allocatable to non-allocatable or vice versa then the metaslab
371 * group's class is updated to reflect the transition.
374 metaslab_group_alloc_update(metaslab_group_t *mg)
376 vdev_t *vd = mg->mg_vd;
377 metaslab_class_t *mc = mg->mg_class;
378 vdev_stat_t *vs = &vd->vdev_stat;
379 boolean_t was_allocatable;
381 ASSERT(vd == vd->vdev_top);
383 mutex_enter(&mg->mg_lock);
384 was_allocatable = mg->mg_allocatable;
386 mg->mg_free_capacity = ((vs->vs_space - vs->vs_alloc) * 100) /
389 mg->mg_allocatable = (mg->mg_free_capacity > zfs_mg_noalloc_threshold);
392 * The mc_alloc_groups maintains a count of the number of
393 * groups in this metaslab class that are still above the
394 * zfs_mg_noalloc_threshold. This is used by the allocating
395 * threads to determine if they should avoid allocations to
396 * a given group. The allocator will avoid allocations to a group
397 * if that group has reached or is below the zfs_mg_noalloc_threshold
398 * and there are still other groups that are above the threshold.
399 * When a group transitions from allocatable to non-allocatable or
400 * vice versa we update the metaslab class to reflect that change.
401 * When the mc_alloc_groups value drops to 0 that means that all
402 * groups have reached the zfs_mg_noalloc_threshold making all groups
403 * eligible for allocations. This effectively means that all devices
404 * are balanced again.
406 if (was_allocatable && !mg->mg_allocatable)
407 mc->mc_alloc_groups--;
408 else if (!was_allocatable && mg->mg_allocatable)
409 mc->mc_alloc_groups++;
410 mutex_exit(&mg->mg_lock);
414 metaslab_group_create(metaslab_class_t *mc, vdev_t *vd)
416 metaslab_group_t *mg;
418 mg = kmem_zalloc(sizeof (metaslab_group_t), KM_SLEEP);
419 mutex_init(&mg->mg_lock, NULL, MUTEX_DEFAULT, NULL);
420 avl_create(&mg->mg_metaslab_tree, metaslab_compare,
421 sizeof (metaslab_t), offsetof(struct metaslab, ms_group_node));
424 mg->mg_activation_count = 0;
426 mg->mg_taskq = taskq_create("metaslab_group_tasksq", metaslab_load_pct,
427 minclsyspri, 10, INT_MAX, TASKQ_THREADS_CPU_PCT);
433 metaslab_group_destroy(metaslab_group_t *mg)
435 ASSERT(mg->mg_prev == NULL);
436 ASSERT(mg->mg_next == NULL);
438 * We may have gone below zero with the activation count
439 * either because we never activated in the first place or
440 * because we're done, and possibly removing the vdev.
442 ASSERT(mg->mg_activation_count <= 0);
444 avl_destroy(&mg->mg_metaslab_tree);
445 mutex_destroy(&mg->mg_lock);
446 kmem_free(mg, sizeof (metaslab_group_t));
450 metaslab_group_activate(metaslab_group_t *mg)
452 metaslab_class_t *mc = mg->mg_class;
453 metaslab_group_t *mgprev, *mgnext;
455 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
457 ASSERT(mc->mc_rotor != mg);
458 ASSERT(mg->mg_prev == NULL);
459 ASSERT(mg->mg_next == NULL);
460 ASSERT(mg->mg_activation_count <= 0);
462 if (++mg->mg_activation_count <= 0)
465 mg->mg_aliquot = metaslab_aliquot * MAX(1, mg->mg_vd->vdev_children);
466 metaslab_group_alloc_update(mg);
468 if ((mgprev = mc->mc_rotor) == NULL) {
472 mgnext = mgprev->mg_next;
473 mg->mg_prev = mgprev;
474 mg->mg_next = mgnext;
475 mgprev->mg_next = mg;
476 mgnext->mg_prev = mg;
479 metaslab_class_minblocksize_update(mc);
483 metaslab_group_passivate(metaslab_group_t *mg)
485 metaslab_class_t *mc = mg->mg_class;
486 metaslab_group_t *mgprev, *mgnext;
488 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
490 if (--mg->mg_activation_count != 0) {
491 ASSERT(mc->mc_rotor != mg);
492 ASSERT(mg->mg_prev == NULL);
493 ASSERT(mg->mg_next == NULL);
494 ASSERT(mg->mg_activation_count < 0);
498 taskq_wait(mg->mg_taskq);
500 mgprev = mg->mg_prev;
501 mgnext = mg->mg_next;
506 mc->mc_rotor = mgnext;
507 mgprev->mg_next = mgnext;
508 mgnext->mg_prev = mgprev;
513 metaslab_class_minblocksize_update(mc);
517 metaslab_group_add(metaslab_group_t *mg, metaslab_t *msp)
519 mutex_enter(&mg->mg_lock);
520 ASSERT(msp->ms_group == NULL);
523 avl_add(&mg->mg_metaslab_tree, msp);
524 mutex_exit(&mg->mg_lock);
528 metaslab_group_remove(metaslab_group_t *mg, metaslab_t *msp)
530 mutex_enter(&mg->mg_lock);
531 ASSERT(msp->ms_group == mg);
532 avl_remove(&mg->mg_metaslab_tree, msp);
533 msp->ms_group = NULL;
534 mutex_exit(&mg->mg_lock);
538 metaslab_group_sort(metaslab_group_t *mg, metaslab_t *msp, uint64_t weight)
541 * Although in principle the weight can be any value, in
542 * practice we do not use values in the range [1, 510].
544 ASSERT(weight >= SPA_MINBLOCKSIZE-1 || weight == 0);
545 ASSERT(MUTEX_HELD(&msp->ms_lock));
547 mutex_enter(&mg->mg_lock);
548 ASSERT(msp->ms_group == mg);
549 avl_remove(&mg->mg_metaslab_tree, msp);
550 msp->ms_weight = weight;
551 avl_add(&mg->mg_metaslab_tree, msp);
552 mutex_exit(&mg->mg_lock);
556 * Determine if a given metaslab group should skip allocations. A metaslab
557 * group should avoid allocations if its used capacity has crossed the
558 * zfs_mg_noalloc_threshold and there is at least one metaslab group
559 * that can still handle allocations.
562 metaslab_group_allocatable(metaslab_group_t *mg)
564 vdev_t *vd = mg->mg_vd;
565 spa_t *spa = vd->vdev_spa;
566 metaslab_class_t *mc = mg->mg_class;
569 * A metaslab group is considered allocatable if its free capacity
570 * is greater than the set value of zfs_mg_noalloc_threshold, it's
571 * associated with a slog, or there are no other metaslab groups
572 * with free capacity greater than zfs_mg_noalloc_threshold.
574 return (mg->mg_free_capacity > zfs_mg_noalloc_threshold ||
575 mc != spa_normal_class(spa) || mc->mc_alloc_groups == 0);
579 * ==========================================================================
580 * Range tree callbacks
581 * ==========================================================================
585 * Comparison function for the private size-ordered tree. Tree is sorted
586 * by size, larger sizes at the end of the tree.
589 metaslab_rangesize_compare(const void *x1, const void *x2)
591 const range_seg_t *r1 = x1;
592 const range_seg_t *r2 = x2;
593 uint64_t rs_size1 = r1->rs_end - r1->rs_start;
594 uint64_t rs_size2 = r2->rs_end - r2->rs_start;
596 if (rs_size1 < rs_size2)
598 if (rs_size1 > rs_size2)
601 if (r1->rs_start < r2->rs_start)
604 if (r1->rs_start > r2->rs_start)
611 * Create any block allocator specific components. The current allocators
612 * rely on using both a size-ordered range_tree_t and an array of uint64_t's.
615 metaslab_rt_create(range_tree_t *rt, void *arg)
617 metaslab_t *msp = arg;
619 ASSERT3P(rt->rt_arg, ==, msp);
620 ASSERT(msp->ms_tree == NULL);
622 avl_create(&msp->ms_size_tree, metaslab_rangesize_compare,
623 sizeof (range_seg_t), offsetof(range_seg_t, rs_pp_node));
627 * Destroy the block allocator specific components.
630 metaslab_rt_destroy(range_tree_t *rt, void *arg)
632 metaslab_t *msp = arg;
634 ASSERT3P(rt->rt_arg, ==, msp);
635 ASSERT3P(msp->ms_tree, ==, rt);
636 ASSERT0(avl_numnodes(&msp->ms_size_tree));
638 avl_destroy(&msp->ms_size_tree);
642 metaslab_rt_add(range_tree_t *rt, range_seg_t *rs, void *arg)
644 metaslab_t *msp = arg;
646 ASSERT3P(rt->rt_arg, ==, msp);
647 ASSERT3P(msp->ms_tree, ==, rt);
648 VERIFY(!msp->ms_condensing);
649 avl_add(&msp->ms_size_tree, rs);
653 metaslab_rt_remove(range_tree_t *rt, range_seg_t *rs, void *arg)
655 metaslab_t *msp = arg;
657 ASSERT3P(rt->rt_arg, ==, msp);
658 ASSERT3P(msp->ms_tree, ==, rt);
659 VERIFY(!msp->ms_condensing);
660 avl_remove(&msp->ms_size_tree, rs);
664 metaslab_rt_vacate(range_tree_t *rt, void *arg)
666 metaslab_t *msp = arg;
668 ASSERT3P(rt->rt_arg, ==, msp);
669 ASSERT3P(msp->ms_tree, ==, rt);
672 * Normally one would walk the tree freeing nodes along the way.
673 * Since the nodes are shared with the range trees we can avoid
674 * walking all nodes and just reinitialize the avl tree. The nodes
675 * will be freed by the range tree, so we don't want to free them here.
677 avl_create(&msp->ms_size_tree, metaslab_rangesize_compare,
678 sizeof (range_seg_t), offsetof(range_seg_t, rs_pp_node));
681 static range_tree_ops_t metaslab_rt_ops = {
690 * ==========================================================================
691 * Metaslab block operations
692 * ==========================================================================
696 * Return the maximum contiguous segment within the metaslab.
699 metaslab_block_maxsize(metaslab_t *msp)
701 avl_tree_t *t = &msp->ms_size_tree;
704 if (t == NULL || (rs = avl_last(t)) == NULL)
707 return (rs->rs_end - rs->rs_start);
711 metaslab_block_alloc(metaslab_t *msp, uint64_t size)
714 range_tree_t *rt = msp->ms_tree;
716 VERIFY(!msp->ms_condensing);
718 start = msp->ms_ops->msop_alloc(msp, size);
719 if (start != -1ULL) {
720 vdev_t *vd = msp->ms_group->mg_vd;
722 VERIFY0(P2PHASE(start, 1ULL << vd->vdev_ashift));
723 VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift));
724 VERIFY3U(range_tree_space(rt) - size, <=, msp->ms_size);
725 range_tree_remove(rt, start, size);
731 * ==========================================================================
732 * Common allocator routines
733 * ==========================================================================
737 * This is a helper function that can be used by the allocator to find
738 * a suitable block to allocate. This will search the specified AVL
739 * tree looking for a block that matches the specified criteria.
742 metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size,
745 range_seg_t *rs, rsearch;
748 rsearch.rs_start = *cursor;
749 rsearch.rs_end = *cursor + size;
751 rs = avl_find(t, &rsearch, &where);
753 rs = avl_nearest(t, where, AVL_AFTER);
756 uint64_t offset = P2ROUNDUP(rs->rs_start, align);
758 if (offset + size <= rs->rs_end) {
759 *cursor = offset + size;
762 rs = AVL_NEXT(t, rs);
766 * If we know we've searched the whole map (*cursor == 0), give up.
767 * Otherwise, reset the cursor to the beginning and try again.
773 return (metaslab_block_picker(t, cursor, size, align));
777 * ==========================================================================
778 * The first-fit block allocator
779 * ==========================================================================
782 metaslab_ff_alloc(metaslab_t *msp, uint64_t size)
785 * Find the largest power of 2 block size that evenly divides the
786 * requested size. This is used to try to allocate blocks with similar
787 * alignment from the same area of the metaslab (i.e. same cursor
788 * bucket) but it does not guarantee that other allocations sizes
789 * may exist in the same region.
791 uint64_t align = size & -size;
792 uint64_t *cursor = &msp->ms_lbas[highbit(align) - 1];
793 avl_tree_t *t = &msp->ms_tree->rt_root;
795 return (metaslab_block_picker(t, cursor, size, align));
800 metaslab_ff_fragmented(metaslab_t *msp)
805 static metaslab_ops_t metaslab_ff_ops = {
807 metaslab_ff_fragmented
811 * ==========================================================================
812 * Dynamic block allocator -
813 * Uses the first fit allocation scheme until space get low and then
814 * adjusts to a best fit allocation method. Uses metaslab_df_alloc_threshold
815 * and metaslab_df_free_pct to determine when to switch the allocation scheme.
816 * ==========================================================================
819 metaslab_df_alloc(metaslab_t *msp, uint64_t size)
822 * Find the largest power of 2 block size that evenly divides the
823 * requested size. This is used to try to allocate blocks with similar
824 * alignment from the same area of the metaslab (i.e. same cursor
825 * bucket) but it does not guarantee that other allocations sizes
826 * may exist in the same region.
828 uint64_t align = size & -size;
829 uint64_t *cursor = &msp->ms_lbas[highbit(align) - 1];
830 range_tree_t *rt = msp->ms_tree;
831 avl_tree_t *t = &rt->rt_root;
832 uint64_t max_size = metaslab_block_maxsize(msp);
833 int free_pct = range_tree_space(rt) * 100 / msp->ms_size;
835 ASSERT(MUTEX_HELD(&msp->ms_lock));
836 ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&msp->ms_size_tree));
842 * If we're running low on space switch to using the size
843 * sorted AVL tree (best-fit).
845 if (max_size < metaslab_df_alloc_threshold ||
846 free_pct < metaslab_df_free_pct) {
847 t = &msp->ms_size_tree;
851 return (metaslab_block_picker(t, cursor, size, 1ULL));
855 metaslab_df_fragmented(metaslab_t *msp)
857 range_tree_t *rt = msp->ms_tree;
858 uint64_t max_size = metaslab_block_maxsize(msp);
859 int free_pct = range_tree_space(rt) * 100 / msp->ms_size;
861 if (max_size >= metaslab_df_alloc_threshold &&
862 free_pct >= metaslab_df_free_pct)
868 static metaslab_ops_t metaslab_df_ops = {
870 metaslab_df_fragmented
874 * ==========================================================================
875 * Cursor fit block allocator -
876 * Select the largest region in the metaslab, set the cursor to the beginning
877 * of the range and the cursor_end to the end of the range. As allocations
878 * are made advance the cursor. Continue allocating from the cursor until
879 * the range is exhausted and then find a new range.
880 * ==========================================================================
883 metaslab_cf_alloc(metaslab_t *msp, uint64_t size)
885 range_tree_t *rt = msp->ms_tree;
886 avl_tree_t *t = &msp->ms_size_tree;
887 uint64_t *cursor = &msp->ms_lbas[0];
888 uint64_t *cursor_end = &msp->ms_lbas[1];
891 ASSERT(MUTEX_HELD(&msp->ms_lock));
892 ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&rt->rt_root));
894 ASSERT3U(*cursor_end, >=, *cursor);
896 if ((*cursor + size) > *cursor_end) {
899 rs = avl_last(&msp->ms_size_tree);
900 if (rs == NULL || (rs->rs_end - rs->rs_start) < size)
903 *cursor = rs->rs_start;
904 *cursor_end = rs->rs_end;
914 metaslab_cf_fragmented(metaslab_t *msp)
916 return (metaslab_block_maxsize(msp) < metaslab_min_alloc_size);
919 static metaslab_ops_t metaslab_cf_ops = {
921 metaslab_cf_fragmented
925 * ==========================================================================
926 * New dynamic fit allocator -
927 * Select a region that is large enough to allocate 2^metaslab_ndf_clump_shift
928 * contiguous blocks. If no region is found then just use the largest segment
930 * ==========================================================================
934 * Determines desired number of contiguous blocks (2^metaslab_ndf_clump_shift)
935 * to request from the allocator.
937 uint64_t metaslab_ndf_clump_shift = 4;
940 metaslab_ndf_alloc(metaslab_t *msp, uint64_t size)
942 avl_tree_t *t = &msp->ms_tree->rt_root;
944 range_seg_t *rs, rsearch;
945 uint64_t hbit = highbit(size);
946 uint64_t *cursor = &msp->ms_lbas[hbit - 1];
947 uint64_t max_size = metaslab_block_maxsize(msp);
949 ASSERT(MUTEX_HELD(&msp->ms_lock));
950 ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&msp->ms_size_tree));
955 rsearch.rs_start = *cursor;
956 rsearch.rs_end = *cursor + size;
958 rs = avl_find(t, &rsearch, &where);
959 if (rs == NULL || (rs->rs_end - rs->rs_start) < size) {
960 t = &msp->ms_size_tree;
962 rsearch.rs_start = 0;
963 rsearch.rs_end = MIN(max_size,
964 1ULL << (hbit + metaslab_ndf_clump_shift));
965 rs = avl_find(t, &rsearch, &where);
967 rs = avl_nearest(t, where, AVL_AFTER);
971 if ((rs->rs_end - rs->rs_start) >= size) {
972 *cursor = rs->rs_start + size;
973 return (rs->rs_start);
979 metaslab_ndf_fragmented(metaslab_t *msp)
981 return (metaslab_block_maxsize(msp) <=
982 (metaslab_min_alloc_size << metaslab_ndf_clump_shift));
985 static metaslab_ops_t metaslab_ndf_ops = {
987 metaslab_ndf_fragmented
990 metaslab_ops_t *zfs_metaslab_ops = &metaslab_df_ops;
993 * ==========================================================================
995 * ==========================================================================
999 * Wait for any in-progress metaslab loads to complete.
1002 metaslab_load_wait(metaslab_t *msp)
1004 ASSERT(MUTEX_HELD(&msp->ms_lock));
1006 while (msp->ms_loading) {
1007 ASSERT(!msp->ms_loaded);
1008 cv_wait(&msp->ms_load_cv, &msp->ms_lock);
1013 metaslab_load(metaslab_t *msp)
1017 ASSERT(MUTEX_HELD(&msp->ms_lock));
1018 ASSERT(!msp->ms_loaded);
1019 ASSERT(!msp->ms_loading);
1021 msp->ms_loading = B_TRUE;
1024 * If the space map has not been allocated yet, then treat
1025 * all the space in the metaslab as free and add it to the
1028 if (msp->ms_sm != NULL)
1029 error = space_map_load(msp->ms_sm, msp->ms_tree, SM_FREE);
1031 range_tree_add(msp->ms_tree, msp->ms_start, msp->ms_size);
1033 msp->ms_loaded = (error == 0);
1034 msp->ms_loading = B_FALSE;
1036 if (msp->ms_loaded) {
1037 for (int t = 0; t < TXG_DEFER_SIZE; t++) {
1038 range_tree_walk(msp->ms_defertree[t],
1039 range_tree_remove, msp->ms_tree);
1042 cv_broadcast(&msp->ms_load_cv);
1047 metaslab_unload(metaslab_t *msp)
1049 ASSERT(MUTEX_HELD(&msp->ms_lock));
1050 range_tree_vacate(msp->ms_tree, NULL, NULL);
1051 msp->ms_loaded = B_FALSE;
1052 msp->ms_weight &= ~METASLAB_ACTIVE_MASK;
1056 metaslab_init(metaslab_group_t *mg, uint64_t id, uint64_t object, uint64_t txg)
1058 vdev_t *vd = mg->mg_vd;
1059 objset_t *mos = vd->vdev_spa->spa_meta_objset;
1062 msp = kmem_zalloc(sizeof (metaslab_t), KM_SLEEP);
1063 mutex_init(&msp->ms_lock, NULL, MUTEX_DEFAULT, NULL);
1064 cv_init(&msp->ms_load_cv, NULL, CV_DEFAULT, NULL);
1066 msp->ms_start = id << vd->vdev_ms_shift;
1067 msp->ms_size = 1ULL << vd->vdev_ms_shift;
1070 * We only open space map objects that already exist. All others
1071 * will be opened when we finally allocate an object for it.
1074 VERIFY0(space_map_open(&msp->ms_sm, mos, object, msp->ms_start,
1075 msp->ms_size, vd->vdev_ashift, &msp->ms_lock));
1076 ASSERT(msp->ms_sm != NULL);
1080 * We create the main range tree here, but we don't create the
1081 * alloctree and freetree until metaslab_sync_done(). This serves
1082 * two purposes: it allows metaslab_sync_done() to detect the
1083 * addition of new space; and for debugging, it ensures that we'd
1084 * data fault on any attempt to use this metaslab before it's ready.
1086 msp->ms_tree = range_tree_create(&metaslab_rt_ops, msp, &msp->ms_lock);
1087 metaslab_group_add(mg, msp);
1089 msp->ms_ops = mg->mg_class->mc_ops;
1092 * If we're opening an existing pool (txg == 0) or creating
1093 * a new one (txg == TXG_INITIAL), all space is available now.
1094 * If we're adding space to an existing pool, the new space
1095 * does not become available until after this txg has synced.
1097 if (txg <= TXG_INITIAL)
1098 metaslab_sync_done(msp, 0);
1101 * If metaslab_debug_load is set and we're initializing a metaslab
1102 * that has an allocated space_map object then load the its space
1103 * map so that can verify frees.
1105 if (metaslab_debug_load && msp->ms_sm != NULL) {
1106 mutex_enter(&msp->ms_lock);
1107 VERIFY0(metaslab_load(msp));
1108 mutex_exit(&msp->ms_lock);
1112 vdev_dirty(vd, 0, NULL, txg);
1113 vdev_dirty(vd, VDD_METASLAB, msp, txg);
1120 metaslab_fini(metaslab_t *msp)
1122 metaslab_group_t *mg = msp->ms_group;
1124 metaslab_group_remove(mg, msp);
1126 mutex_enter(&msp->ms_lock);
1128 VERIFY(msp->ms_group == NULL);
1129 vdev_space_update(mg->mg_vd, -space_map_allocated(msp->ms_sm),
1131 space_map_close(msp->ms_sm);
1133 metaslab_unload(msp);
1134 range_tree_destroy(msp->ms_tree);
1136 for (int t = 0; t < TXG_SIZE; t++) {
1137 range_tree_destroy(msp->ms_alloctree[t]);
1138 range_tree_destroy(msp->ms_freetree[t]);
1141 for (int t = 0; t < TXG_DEFER_SIZE; t++) {
1142 range_tree_destroy(msp->ms_defertree[t]);
1145 ASSERT0(msp->ms_deferspace);
1147 mutex_exit(&msp->ms_lock);
1148 cv_destroy(&msp->ms_load_cv);
1149 mutex_destroy(&msp->ms_lock);
1151 kmem_free(msp, sizeof (metaslab_t));
1155 * Apply a weighting factor based on the histogram information for this
1156 * metaslab. The current weighting factor is somewhat arbitrary and requires
1157 * additional investigation. The implementation provides a measure of
1158 * "weighted" free space and gives a higher weighting for larger contiguous
1159 * regions. The weighting factor is determined by counting the number of
1160 * sm_shift sectors that exist in each region represented by the histogram.
1161 * That value is then multiplied by the power of 2 exponent and the sm_shift
1164 * For example, assume the 2^21 histogram bucket has 4 2MB regions and the
1165 * metaslab has an sm_shift value of 9 (512B):
1167 * 1) calculate the number of sm_shift sectors in the region:
1168 * 2^21 / 2^9 = 2^12 = 4096 * 4 (number of regions) = 16384
1169 * 2) multiply by the power of 2 exponent and the sm_shift value:
1170 * 16384 * 21 * 9 = 3096576
1171 * This value will be added to the weighting of the metaslab.
1174 metaslab_weight_factor(metaslab_t *msp)
1176 uint64_t factor = 0;
1181 * A null space map means that the entire metaslab is free,
1182 * calculate a weight factor that spans the entire size of the
1185 if (msp->ms_sm == NULL) {
1186 vdev_t *vd = msp->ms_group->mg_vd;
1188 i = highbit(msp->ms_size) - 1;
1189 sectors = msp->ms_size >> vd->vdev_ashift;
1190 return (sectors * i * vd->vdev_ashift);
1193 if (msp->ms_sm->sm_dbuf->db_size != sizeof (space_map_phys_t))
1196 for (i = 0; i < SPACE_MAP_HISTOGRAM_SIZE(msp->ms_sm); i++) {
1197 if (msp->ms_sm->sm_phys->smp_histogram[i] == 0)
1201 * Determine the number of sm_shift sectors in the region
1202 * indicated by the histogram. For example, given an
1203 * sm_shift value of 9 (512 bytes) and i = 4 then we know
1204 * that we're looking at an 8K region in the histogram
1205 * (i.e. 9 + 4 = 13, 2^13 = 8192). To figure out the
1206 * number of sm_shift sectors (512 bytes in this example),
1207 * we would take 8192 / 512 = 16. Since the histogram
1208 * is offset by sm_shift we can simply use the value of
1209 * of i to calculate this (i.e. 2^i = 16 where i = 4).
1211 sectors = msp->ms_sm->sm_phys->smp_histogram[i] << i;
1212 factor += (i + msp->ms_sm->sm_shift) * sectors;
1214 return (factor * msp->ms_sm->sm_shift);
1218 metaslab_weight(metaslab_t *msp)
1220 metaslab_group_t *mg = msp->ms_group;
1221 vdev_t *vd = mg->mg_vd;
1222 uint64_t weight, space;
1224 ASSERT(MUTEX_HELD(&msp->ms_lock));
1227 * This vdev is in the process of being removed so there is nothing
1228 * for us to do here.
1230 if (vd->vdev_removing) {
1231 ASSERT0(space_map_allocated(msp->ms_sm));
1232 ASSERT0(vd->vdev_ms_shift);
1237 * The baseline weight is the metaslab's free space.
1239 space = msp->ms_size - space_map_allocated(msp->ms_sm);
1243 * Modern disks have uniform bit density and constant angular velocity.
1244 * Therefore, the outer recording zones are faster (higher bandwidth)
1245 * than the inner zones by the ratio of outer to inner track diameter,
1246 * which is typically around 2:1. We account for this by assigning
1247 * higher weight to lower metaslabs (multiplier ranging from 2x to 1x).
1248 * In effect, this means that we'll select the metaslab with the most
1249 * free bandwidth rather than simply the one with the most free space.
1251 weight = 2 * weight - (msp->ms_id * weight) / vd->vdev_ms_count;
1252 ASSERT(weight >= space && weight <= 2 * space);
1254 msp->ms_factor = metaslab_weight_factor(msp);
1255 if (metaslab_weight_factor_enable)
1256 weight += msp->ms_factor;
1258 if (msp->ms_loaded && !msp->ms_ops->msop_fragmented(msp)) {
1260 * If this metaslab is one we're actively using, adjust its
1261 * weight to make it preferable to any inactive metaslab so
1262 * we'll polish it off.
1264 weight |= (msp->ms_weight & METASLAB_ACTIVE_MASK);
1271 metaslab_activate(metaslab_t *msp, uint64_t activation_weight)
1273 ASSERT(MUTEX_HELD(&msp->ms_lock));
1275 if ((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
1276 metaslab_load_wait(msp);
1277 if (!msp->ms_loaded) {
1278 int error = metaslab_load(msp);
1280 metaslab_group_sort(msp->ms_group, msp, 0);
1285 metaslab_group_sort(msp->ms_group, msp,
1286 msp->ms_weight | activation_weight);
1288 ASSERT(msp->ms_loaded);
1289 ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK);
1295 metaslab_passivate(metaslab_t *msp, uint64_t size)
1298 * If size < SPA_MINBLOCKSIZE, then we will not allocate from
1299 * this metaslab again. In that case, it had better be empty,
1300 * or we would be leaving space on the table.
1302 ASSERT(size >= SPA_MINBLOCKSIZE || range_tree_space(msp->ms_tree) == 0);
1303 metaslab_group_sort(msp->ms_group, msp, MIN(msp->ms_weight, size));
1304 ASSERT((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0);
1308 metaslab_preload(void *arg)
1310 metaslab_t *msp = arg;
1311 spa_t *spa = msp->ms_group->mg_vd->vdev_spa;
1313 mutex_enter(&msp->ms_lock);
1314 metaslab_load_wait(msp);
1315 if (!msp->ms_loaded)
1316 (void) metaslab_load(msp);
1319 * Set the ms_access_txg value so that we don't unload it right away.
1321 msp->ms_access_txg = spa_syncing_txg(spa) + metaslab_unload_delay + 1;
1322 mutex_exit(&msp->ms_lock);
1326 metaslab_group_preload(metaslab_group_t *mg)
1328 spa_t *spa = mg->mg_vd->vdev_spa;
1330 avl_tree_t *t = &mg->mg_metaslab_tree;
1333 if (spa_shutting_down(spa) || !metaslab_preload_enabled) {
1334 taskq_wait(mg->mg_taskq);
1337 mutex_enter(&mg->mg_lock);
1340 * Prefetch the next potential metaslabs
1342 for (msp = avl_first(t); msp != NULL; msp = AVL_NEXT(t, msp)) {
1344 /* If we have reached our preload limit then we're done */
1345 if (++m > metaslab_preload_limit)
1348 VERIFY(taskq_dispatch(mg->mg_taskq, metaslab_preload,
1349 msp, TQ_SLEEP) != 0);
1351 mutex_exit(&mg->mg_lock);
1355 * Determine if the space map's on-disk footprint is past our tolerance
1356 * for inefficiency. We would like to use the following criteria to make
1359 * 1. The size of the space map object should not dramatically increase as a
1360 * result of writing out the free space range tree.
1362 * 2. The minimal on-disk space map representation is zfs_condense_pct/100
1363 * times the size than the free space range tree representation
1364 * (i.e. zfs_condense_pct = 110 and in-core = 1MB, minimal = 1.1.MB).
1366 * Checking the first condition is tricky since we don't want to walk
1367 * the entire AVL tree calculating the estimated on-disk size. Instead we
1368 * use the size-ordered range tree in the metaslab and calculate the
1369 * size required to write out the largest segment in our free tree. If the
1370 * size required to represent that segment on disk is larger than the space
1371 * map object then we avoid condensing this map.
1373 * To determine the second criterion we use a best-case estimate and assume
1374 * each segment can be represented on-disk as a single 64-bit entry. We refer
1375 * to this best-case estimate as the space map's minimal form.
1378 metaslab_should_condense(metaslab_t *msp)
1380 space_map_t *sm = msp->ms_sm;
1382 uint64_t size, entries, segsz;
1384 ASSERT(MUTEX_HELD(&msp->ms_lock));
1385 ASSERT(msp->ms_loaded);
1388 * Use the ms_size_tree range tree, which is ordered by size, to
1389 * obtain the largest segment in the free tree. If the tree is empty
1390 * then we should condense the map.
1392 rs = avl_last(&msp->ms_size_tree);
1397 * Calculate the number of 64-bit entries this segment would
1398 * require when written to disk. If this single segment would be
1399 * larger on-disk than the entire current on-disk structure, then
1400 * clearly condensing will increase the on-disk structure size.
1402 size = (rs->rs_end - rs->rs_start) >> sm->sm_shift;
1403 entries = size / (MIN(size, SM_RUN_MAX));
1404 segsz = entries * sizeof (uint64_t);
1406 return (segsz <= space_map_length(msp->ms_sm) &&
1407 space_map_length(msp->ms_sm) >= (zfs_condense_pct *
1408 sizeof (uint64_t) * avl_numnodes(&msp->ms_tree->rt_root)) / 100);
1412 * Condense the on-disk space map representation to its minimized form.
1413 * The minimized form consists of a small number of allocations followed by
1414 * the entries of the free range tree.
1417 metaslab_condense(metaslab_t *msp, uint64_t txg, dmu_tx_t *tx)
1419 spa_t *spa = msp->ms_group->mg_vd->vdev_spa;
1420 range_tree_t *freetree = msp->ms_freetree[txg & TXG_MASK];
1421 range_tree_t *condense_tree;
1422 space_map_t *sm = msp->ms_sm;
1424 ASSERT(MUTEX_HELD(&msp->ms_lock));
1425 ASSERT3U(spa_sync_pass(spa), ==, 1);
1426 ASSERT(msp->ms_loaded);
1428 spa_dbgmsg(spa, "condensing: txg %llu, msp[%llu] %p, "
1429 "smp size %llu, segments %lu", txg, msp->ms_id, msp,
1430 space_map_length(msp->ms_sm), avl_numnodes(&msp->ms_tree->rt_root));
1433 * Create an range tree that is 100% allocated. We remove segments
1434 * that have been freed in this txg, any deferred frees that exist,
1435 * and any allocation in the future. Removing segments should be
1436 * a relatively inexpensive operation since we expect these trees to
1437 * have a small number of nodes.
1439 condense_tree = range_tree_create(NULL, NULL, &msp->ms_lock);
1440 range_tree_add(condense_tree, msp->ms_start, msp->ms_size);
1443 * Remove what's been freed in this txg from the condense_tree.
1444 * Since we're in sync_pass 1, we know that all the frees from
1445 * this txg are in the freetree.
1447 range_tree_walk(freetree, range_tree_remove, condense_tree);
1449 for (int t = 0; t < TXG_DEFER_SIZE; t++) {
1450 range_tree_walk(msp->ms_defertree[t],
1451 range_tree_remove, condense_tree);
1454 for (int t = 1; t < TXG_CONCURRENT_STATES; t++) {
1455 range_tree_walk(msp->ms_alloctree[(txg + t) & TXG_MASK],
1456 range_tree_remove, condense_tree);
1460 * We're about to drop the metaslab's lock thus allowing
1461 * other consumers to change it's content. Set the
1462 * metaslab's ms_condensing flag to ensure that
1463 * allocations on this metaslab do not occur while we're
1464 * in the middle of committing it to disk. This is only critical
1465 * for the ms_tree as all other range trees use per txg
1466 * views of their content.
1468 msp->ms_condensing = B_TRUE;
1470 mutex_exit(&msp->ms_lock);
1471 space_map_truncate(sm, tx);
1472 mutex_enter(&msp->ms_lock);
1475 * While we would ideally like to create a space_map representation
1476 * that consists only of allocation records, doing so can be
1477 * prohibitively expensive because the in-core free tree can be
1478 * large, and therefore computationally expensive to subtract
1479 * from the condense_tree. Instead we sync out two trees, a cheap
1480 * allocation only tree followed by the in-core free tree. While not
1481 * optimal, this is typically close to optimal, and much cheaper to
1484 space_map_write(sm, condense_tree, SM_ALLOC, tx);
1485 range_tree_vacate(condense_tree, NULL, NULL);
1486 range_tree_destroy(condense_tree);
1488 space_map_write(sm, msp->ms_tree, SM_FREE, tx);
1489 msp->ms_condensing = B_FALSE;
1493 * Write a metaslab to disk in the context of the specified transaction group.
1496 metaslab_sync(metaslab_t *msp, uint64_t txg)
1498 metaslab_group_t *mg = msp->ms_group;
1499 vdev_t *vd = mg->mg_vd;
1500 spa_t *spa = vd->vdev_spa;
1501 objset_t *mos = spa_meta_objset(spa);
1502 range_tree_t *alloctree = msp->ms_alloctree[txg & TXG_MASK];
1503 range_tree_t **freetree = &msp->ms_freetree[txg & TXG_MASK];
1504 range_tree_t **freed_tree =
1505 &msp->ms_freetree[TXG_CLEAN(txg) & TXG_MASK];
1507 uint64_t object = space_map_object(msp->ms_sm);
1509 ASSERT(!vd->vdev_ishole);
1512 * This metaslab has just been added so there's no work to do now.
1514 if (*freetree == NULL) {
1515 ASSERT3P(alloctree, ==, NULL);
1519 ASSERT3P(alloctree, !=, NULL);
1520 ASSERT3P(*freetree, !=, NULL);
1521 ASSERT3P(*freed_tree, !=, NULL);
1523 if (range_tree_space(alloctree) == 0 &&
1524 range_tree_space(*freetree) == 0)
1528 * The only state that can actually be changing concurrently with
1529 * metaslab_sync() is the metaslab's ms_tree. No other thread can
1530 * be modifying this txg's alloctree, freetree, freed_tree, or
1531 * space_map_phys_t. Therefore, we only hold ms_lock to satify
1532 * space_map ASSERTs. We drop it whenever we call into the DMU,
1533 * because the DMU can call down to us (e.g. via zio_free()) at
1537 tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg);
1539 if (msp->ms_sm == NULL) {
1540 uint64_t new_object;
1542 new_object = space_map_alloc(mos, tx);
1543 VERIFY3U(new_object, !=, 0);
1545 VERIFY0(space_map_open(&msp->ms_sm, mos, new_object,
1546 msp->ms_start, msp->ms_size, vd->vdev_ashift,
1548 ASSERT(msp->ms_sm != NULL);
1551 mutex_enter(&msp->ms_lock);
1553 if (msp->ms_loaded && spa_sync_pass(spa) == 1 &&
1554 metaslab_should_condense(msp)) {
1555 metaslab_condense(msp, txg, tx);
1557 space_map_write(msp->ms_sm, alloctree, SM_ALLOC, tx);
1558 space_map_write(msp->ms_sm, *freetree, SM_FREE, tx);
1561 range_tree_vacate(alloctree, NULL, NULL);
1563 if (msp->ms_loaded) {
1565 * When the space map is loaded, we have an accruate
1566 * histogram in the range tree. This gives us an opportunity
1567 * to bring the space map's histogram up-to-date so we clear
1568 * it first before updating it.
1570 space_map_histogram_clear(msp->ms_sm);
1571 space_map_histogram_add(msp->ms_sm, msp->ms_tree, tx);
1574 * Since the space map is not loaded we simply update the
1575 * exisiting histogram with what was freed in this txg. This
1576 * means that the on-disk histogram may not have an accurate
1577 * view of the free space but it's close enough to allow
1578 * us to make allocation decisions.
1580 space_map_histogram_add(msp->ms_sm, *freetree, tx);
1584 * For sync pass 1, we avoid traversing this txg's free range tree
1585 * and instead will just swap the pointers for freetree and
1586 * freed_tree. We can safely do this since the freed_tree is
1587 * guaranteed to be empty on the initial pass.
1589 if (spa_sync_pass(spa) == 1) {
1590 range_tree_swap(freetree, freed_tree);
1592 range_tree_vacate(*freetree, range_tree_add, *freed_tree);
1595 ASSERT0(range_tree_space(msp->ms_alloctree[txg & TXG_MASK]));
1596 ASSERT0(range_tree_space(msp->ms_freetree[txg & TXG_MASK]));
1598 mutex_exit(&msp->ms_lock);
1600 if (object != space_map_object(msp->ms_sm)) {
1601 object = space_map_object(msp->ms_sm);
1602 dmu_write(mos, vd->vdev_ms_array, sizeof (uint64_t) *
1603 msp->ms_id, sizeof (uint64_t), &object, tx);
1609 * Called after a transaction group has completely synced to mark
1610 * all of the metaslab's free space as usable.
1613 metaslab_sync_done(metaslab_t *msp, uint64_t txg)
1615 metaslab_group_t *mg = msp->ms_group;
1616 vdev_t *vd = mg->mg_vd;
1617 range_tree_t **freed_tree;
1618 range_tree_t **defer_tree;
1619 int64_t alloc_delta, defer_delta;
1621 ASSERT(!vd->vdev_ishole);
1623 mutex_enter(&msp->ms_lock);
1626 * If this metaslab is just becoming available, initialize its
1627 * alloctrees, freetrees, and defertree and add its capacity to
1630 if (msp->ms_freetree[TXG_CLEAN(txg) & TXG_MASK] == NULL) {
1631 for (int t = 0; t < TXG_SIZE; t++) {
1632 ASSERT(msp->ms_alloctree[t] == NULL);
1633 ASSERT(msp->ms_freetree[t] == NULL);
1635 msp->ms_alloctree[t] = range_tree_create(NULL, msp,
1637 msp->ms_freetree[t] = range_tree_create(NULL, msp,
1641 for (int t = 0; t < TXG_DEFER_SIZE; t++) {
1642 ASSERT(msp->ms_defertree[t] == NULL);
1644 msp->ms_defertree[t] = range_tree_create(NULL, msp,
1648 vdev_space_update(vd, 0, 0, msp->ms_size);
1651 freed_tree = &msp->ms_freetree[TXG_CLEAN(txg) & TXG_MASK];
1652 defer_tree = &msp->ms_defertree[txg % TXG_DEFER_SIZE];
1654 alloc_delta = space_map_alloc_delta(msp->ms_sm);
1655 defer_delta = range_tree_space(*freed_tree) -
1656 range_tree_space(*defer_tree);
1658 vdev_space_update(vd, alloc_delta + defer_delta, defer_delta, 0);
1660 ASSERT0(range_tree_space(msp->ms_alloctree[txg & TXG_MASK]));
1661 ASSERT0(range_tree_space(msp->ms_freetree[txg & TXG_MASK]));
1664 * If there's a metaslab_load() in progress, wait for it to complete
1665 * so that we have a consistent view of the in-core space map.
1667 metaslab_load_wait(msp);
1670 * Move the frees from the defer_tree back to the free
1671 * range tree (if it's loaded). Swap the freed_tree and the
1672 * defer_tree -- this is safe to do because we've just emptied out
1675 range_tree_vacate(*defer_tree,
1676 msp->ms_loaded ? range_tree_add : NULL, msp->ms_tree);
1677 range_tree_swap(freed_tree, defer_tree);
1679 space_map_update(msp->ms_sm);
1681 msp->ms_deferspace += defer_delta;
1682 ASSERT3S(msp->ms_deferspace, >=, 0);
1683 ASSERT3S(msp->ms_deferspace, <=, msp->ms_size);
1684 if (msp->ms_deferspace != 0) {
1686 * Keep syncing this metaslab until all deferred frees
1687 * are back in circulation.
1689 vdev_dirty(vd, VDD_METASLAB, msp, txg + 1);
1692 if (msp->ms_loaded && msp->ms_access_txg < txg) {
1693 for (int t = 1; t < TXG_CONCURRENT_STATES; t++) {
1694 VERIFY0(range_tree_space(
1695 msp->ms_alloctree[(txg + t) & TXG_MASK]));
1698 if (!metaslab_debug_unload)
1699 metaslab_unload(msp);
1702 metaslab_group_sort(mg, msp, metaslab_weight(msp));
1703 mutex_exit(&msp->ms_lock);
1708 metaslab_sync_reassess(metaslab_group_t *mg)
1710 int64_t failures = mg->mg_alloc_failures;
1712 metaslab_group_alloc_update(mg);
1713 atomic_add_64(&mg->mg_alloc_failures, -failures);
1716 * Preload the next potential metaslabs
1718 metaslab_group_preload(mg);
1722 metaslab_distance(metaslab_t *msp, dva_t *dva)
1724 uint64_t ms_shift = msp->ms_group->mg_vd->vdev_ms_shift;
1725 uint64_t offset = DVA_GET_OFFSET(dva) >> ms_shift;
1726 uint64_t start = msp->ms_id;
1728 if (msp->ms_group->mg_vd->vdev_id != DVA_GET_VDEV(dva))
1729 return (1ULL << 63);
1732 return ((start - offset) << ms_shift);
1734 return ((offset - start) << ms_shift);
1739 metaslab_group_alloc(metaslab_group_t *mg, uint64_t psize, uint64_t asize,
1740 uint64_t txg, uint64_t min_distance, dva_t *dva, int d, int flags)
1742 spa_t *spa = mg->mg_vd->vdev_spa;
1743 metaslab_t *msp = NULL;
1744 uint64_t offset = -1ULL;
1745 avl_tree_t *t = &mg->mg_metaslab_tree;
1746 uint64_t activation_weight;
1747 uint64_t target_distance;
1750 activation_weight = METASLAB_WEIGHT_PRIMARY;
1751 for (i = 0; i < d; i++) {
1752 if (DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) {
1753 activation_weight = METASLAB_WEIGHT_SECONDARY;
1759 boolean_t was_active;
1761 mutex_enter(&mg->mg_lock);
1762 for (msp = avl_first(t); msp; msp = AVL_NEXT(t, msp)) {
1763 if (msp->ms_weight < asize) {
1764 spa_dbgmsg(spa, "%s: failed to meet weight "
1765 "requirement: vdev %llu, txg %llu, mg %p, "
1766 "msp %p, psize %llu, asize %llu, "
1767 "failures %llu, weight %llu",
1768 spa_name(spa), mg->mg_vd->vdev_id, txg,
1769 mg, msp, psize, asize,
1770 mg->mg_alloc_failures, msp->ms_weight);
1771 mutex_exit(&mg->mg_lock);
1776 * If the selected metaslab is condensing, skip it.
1778 if (msp->ms_condensing)
1781 was_active = msp->ms_weight & METASLAB_ACTIVE_MASK;
1782 if (activation_weight == METASLAB_WEIGHT_PRIMARY)
1785 target_distance = min_distance +
1786 (space_map_allocated(msp->ms_sm) != 0 ? 0 :
1789 for (i = 0; i < d; i++)
1790 if (metaslab_distance(msp, &dva[i]) <
1796 mutex_exit(&mg->mg_lock);
1800 mutex_enter(&msp->ms_lock);
1803 * If we've already reached the allowable number of failed
1804 * allocation attempts on this metaslab group then we
1805 * consider skipping it. We skip it only if we're allowed
1806 * to "fast" gang, the physical size is larger than
1807 * a gang block, and we're attempting to allocate from
1808 * the primary metaslab.
1810 if (mg->mg_alloc_failures > zfs_mg_alloc_failures &&
1811 CAN_FASTGANG(flags) && psize > SPA_GANGBLOCKSIZE &&
1812 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1813 spa_dbgmsg(spa, "%s: skipping metaslab group: "
1814 "vdev %llu, txg %llu, mg %p, msp[%llu] %p, "
1815 "psize %llu, asize %llu, failures %llu",
1816 spa_name(spa), mg->mg_vd->vdev_id, txg, mg,
1817 msp->ms_id, msp, psize, asize,
1818 mg->mg_alloc_failures);
1819 mutex_exit(&msp->ms_lock);
1824 * Ensure that the metaslab we have selected is still
1825 * capable of handling our request. It's possible that
1826 * another thread may have changed the weight while we
1827 * were blocked on the metaslab lock.
1829 if (msp->ms_weight < asize || (was_active &&
1830 !(msp->ms_weight & METASLAB_ACTIVE_MASK) &&
1831 activation_weight == METASLAB_WEIGHT_PRIMARY)) {
1832 mutex_exit(&msp->ms_lock);
1836 if ((msp->ms_weight & METASLAB_WEIGHT_SECONDARY) &&
1837 activation_weight == METASLAB_WEIGHT_PRIMARY) {
1838 metaslab_passivate(msp,
1839 msp->ms_weight & ~METASLAB_ACTIVE_MASK);
1840 mutex_exit(&msp->ms_lock);
1844 if (metaslab_activate(msp, activation_weight) != 0) {
1845 mutex_exit(&msp->ms_lock);
1850 * If this metaslab is currently condensing then pick again as
1851 * we can't manipulate this metaslab until it's committed
1854 if (msp->ms_condensing) {
1855 mutex_exit(&msp->ms_lock);
1859 if ((offset = metaslab_block_alloc(msp, asize)) != -1ULL)
1862 atomic_inc_64(&mg->mg_alloc_failures);
1864 metaslab_passivate(msp, metaslab_block_maxsize(msp));
1865 mutex_exit(&msp->ms_lock);
1868 if (range_tree_space(msp->ms_alloctree[txg & TXG_MASK]) == 0)
1869 vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg);
1871 range_tree_add(msp->ms_alloctree[txg & TXG_MASK], offset, asize);
1872 msp->ms_access_txg = txg + metaslab_unload_delay;
1874 mutex_exit(&msp->ms_lock);
1880 * Allocate a block for the specified i/o.
1883 metaslab_alloc_dva(spa_t *spa, metaslab_class_t *mc, uint64_t psize,
1884 dva_t *dva, int d, dva_t *hintdva, uint64_t txg, int flags)
1886 metaslab_group_t *mg, *rotor;
1890 int zio_lock = B_FALSE;
1891 boolean_t allocatable;
1892 uint64_t offset = -1ULL;
1896 ASSERT(!DVA_IS_VALID(&dva[d]));
1899 * For testing, make some blocks above a certain size be gang blocks.
1901 if (psize >= metaslab_gang_bang && (ddi_get_lbolt() & 3) == 0)
1902 return (SET_ERROR(ENOSPC));
1905 * Start at the rotor and loop through all mgs until we find something.
1906 * Note that there's no locking on mc_rotor or mc_aliquot because
1907 * nothing actually breaks if we miss a few updates -- we just won't
1908 * allocate quite as evenly. It all balances out over time.
1910 * If we are doing ditto or log blocks, try to spread them across
1911 * consecutive vdevs. If we're forced to reuse a vdev before we've
1912 * allocated all of our ditto blocks, then try and spread them out on
1913 * that vdev as much as possible. If it turns out to not be possible,
1914 * gradually lower our standards until anything becomes acceptable.
1915 * Also, allocating on consecutive vdevs (as opposed to random vdevs)
1916 * gives us hope of containing our fault domains to something we're
1917 * able to reason about. Otherwise, any two top-level vdev failures
1918 * will guarantee the loss of data. With consecutive allocation,
1919 * only two adjacent top-level vdev failures will result in data loss.
1921 * If we are doing gang blocks (hintdva is non-NULL), try to keep
1922 * ourselves on the same vdev as our gang block header. That
1923 * way, we can hope for locality in vdev_cache, plus it makes our
1924 * fault domains something tractable.
1927 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&hintdva[d]));
1930 * It's possible the vdev we're using as the hint no
1931 * longer exists (i.e. removed). Consult the rotor when
1937 if (flags & METASLAB_HINTBP_AVOID &&
1938 mg->mg_next != NULL)
1943 } else if (d != 0) {
1944 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[d - 1]));
1945 mg = vd->vdev_mg->mg_next;
1951 * If the hint put us into the wrong metaslab class, or into a
1952 * metaslab group that has been passivated, just follow the rotor.
1954 if (mg->mg_class != mc || mg->mg_activation_count <= 0)
1961 ASSERT(mg->mg_activation_count == 1);
1966 * Don't allocate from faulted devices.
1969 spa_config_enter(spa, SCL_ZIO, FTAG, RW_READER);
1970 allocatable = vdev_allocatable(vd);
1971 spa_config_exit(spa, SCL_ZIO, FTAG);
1973 allocatable = vdev_allocatable(vd);
1977 * Determine if the selected metaslab group is eligible
1978 * for allocations. If we're ganging or have requested
1979 * an allocation for the smallest gang block size
1980 * then we don't want to avoid allocating to the this
1981 * metaslab group. If we're in this condition we should
1982 * try to allocate from any device possible so that we
1983 * don't inadvertently return ENOSPC and suspend the pool
1984 * even though space is still available.
1986 if (allocatable && CAN_FASTGANG(flags) &&
1987 psize > SPA_GANGBLOCKSIZE)
1988 allocatable = metaslab_group_allocatable(mg);
1994 * Avoid writing single-copy data to a failing vdev
1995 * unless the user instructs us that it is okay.
1997 if ((vd->vdev_stat.vs_write_errors > 0 ||
1998 vd->vdev_state < VDEV_STATE_HEALTHY) &&
1999 d == 0 && dshift == 3 &&
2000 !(zfs_write_to_degraded && vd->vdev_state ==
2001 VDEV_STATE_DEGRADED)) {
2006 ASSERT(mg->mg_class == mc);
2008 distance = vd->vdev_asize >> dshift;
2009 if (distance <= (1ULL << vd->vdev_ms_shift))
2014 asize = vdev_psize_to_asize(vd, psize);
2015 ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0);
2017 offset = metaslab_group_alloc(mg, psize, asize, txg, distance,
2019 if (offset != -1ULL) {
2021 * If we've just selected this metaslab group,
2022 * figure out whether the corresponding vdev is
2023 * over- or under-used relative to the pool,
2024 * and set an allocation bias to even it out.
2026 if (mc->mc_aliquot == 0) {
2027 vdev_stat_t *vs = &vd->vdev_stat;
2030 vu = (vs->vs_alloc * 100) / (vs->vs_space + 1);
2031 cu = (mc->mc_alloc * 100) / (mc->mc_space + 1);
2034 * Calculate how much more or less we should
2035 * try to allocate from this device during
2036 * this iteration around the rotor.
2037 * For example, if a device is 80% full
2038 * and the pool is 20% full then we should
2039 * reduce allocations by 60% on this device.
2041 * mg_bias = (20 - 80) * 512K / 100 = -307K
2043 * This reduces allocations by 307K for this
2046 mg->mg_bias = ((cu - vu) *
2047 (int64_t)mg->mg_aliquot) / 100;
2050 if (atomic_add_64_nv(&mc->mc_aliquot, asize) >=
2051 mg->mg_aliquot + mg->mg_bias) {
2052 mc->mc_rotor = mg->mg_next;
2056 DVA_SET_VDEV(&dva[d], vd->vdev_id);
2057 DVA_SET_OFFSET(&dva[d], offset);
2058 DVA_SET_GANG(&dva[d], !!(flags & METASLAB_GANG_HEADER));
2059 DVA_SET_ASIZE(&dva[d], asize);
2064 mc->mc_rotor = mg->mg_next;
2066 } while ((mg = mg->mg_next) != rotor);
2070 ASSERT(dshift < 64);
2074 if (!allocatable && !zio_lock) {
2080 bzero(&dva[d], sizeof (dva_t));
2082 return (SET_ERROR(ENOSPC));
2086 * Free the block represented by DVA in the context of the specified
2087 * transaction group.
2090 metaslab_free_dva(spa_t *spa, const dva_t *dva, uint64_t txg, boolean_t now)
2092 uint64_t vdev = DVA_GET_VDEV(dva);
2093 uint64_t offset = DVA_GET_OFFSET(dva);
2094 uint64_t size = DVA_GET_ASIZE(dva);
2098 ASSERT(DVA_IS_VALID(dva));
2100 if (txg > spa_freeze_txg(spa))
2103 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
2104 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count) {
2105 cmn_err(CE_WARN, "metaslab_free_dva(): bad DVA %llu:%llu",
2106 (u_longlong_t)vdev, (u_longlong_t)offset);
2111 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
2113 if (DVA_GET_GANG(dva))
2114 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
2116 mutex_enter(&msp->ms_lock);
2119 range_tree_remove(msp->ms_alloctree[txg & TXG_MASK],
2122 VERIFY(!msp->ms_condensing);
2123 VERIFY3U(offset, >=, msp->ms_start);
2124 VERIFY3U(offset + size, <=, msp->ms_start + msp->ms_size);
2125 VERIFY3U(range_tree_space(msp->ms_tree) + size, <=,
2127 VERIFY0(P2PHASE(offset, 1ULL << vd->vdev_ashift));
2128 VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift));
2129 range_tree_add(msp->ms_tree, offset, size);
2131 if (range_tree_space(msp->ms_freetree[txg & TXG_MASK]) == 0)
2132 vdev_dirty(vd, VDD_METASLAB, msp, txg);
2133 range_tree_add(msp->ms_freetree[txg & TXG_MASK],
2137 mutex_exit(&msp->ms_lock);
2141 * Intent log support: upon opening the pool after a crash, notify the SPA
2142 * of blocks that the intent log has allocated for immediate write, but
2143 * which are still considered free by the SPA because the last transaction
2144 * group didn't commit yet.
2147 metaslab_claim_dva(spa_t *spa, const dva_t *dva, uint64_t txg)
2149 uint64_t vdev = DVA_GET_VDEV(dva);
2150 uint64_t offset = DVA_GET_OFFSET(dva);
2151 uint64_t size = DVA_GET_ASIZE(dva);
2156 ASSERT(DVA_IS_VALID(dva));
2158 if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
2159 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count)
2160 return (SET_ERROR(ENXIO));
2162 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
2164 if (DVA_GET_GANG(dva))
2165 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
2167 mutex_enter(&msp->ms_lock);
2169 if ((txg != 0 && spa_writeable(spa)) || !msp->ms_loaded)
2170 error = metaslab_activate(msp, METASLAB_WEIGHT_SECONDARY);
2172 if (error == 0 && !range_tree_contains(msp->ms_tree, offset, size))
2173 error = SET_ERROR(ENOENT);
2175 if (error || txg == 0) { /* txg == 0 indicates dry run */
2176 mutex_exit(&msp->ms_lock);
2180 VERIFY(!msp->ms_condensing);
2181 VERIFY0(P2PHASE(offset, 1ULL << vd->vdev_ashift));
2182 VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift));
2183 VERIFY3U(range_tree_space(msp->ms_tree) - size, <=, msp->ms_size);
2184 range_tree_remove(msp->ms_tree, offset, size);
2186 if (spa_writeable(spa)) { /* don't dirty if we're zdb(1M) */
2187 if (range_tree_space(msp->ms_alloctree[txg & TXG_MASK]) == 0)
2188 vdev_dirty(vd, VDD_METASLAB, msp, txg);
2189 range_tree_add(msp->ms_alloctree[txg & TXG_MASK], offset, size);
2192 mutex_exit(&msp->ms_lock);
2198 metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp,
2199 int ndvas, uint64_t txg, blkptr_t *hintbp, int flags)
2201 dva_t *dva = bp->blk_dva;
2202 dva_t *hintdva = hintbp->blk_dva;
2205 ASSERT(bp->blk_birth == 0);
2206 ASSERT(BP_PHYSICAL_BIRTH(bp) == 0);
2208 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
2210 if (mc->mc_rotor == NULL) { /* no vdevs in this class */
2211 spa_config_exit(spa, SCL_ALLOC, FTAG);
2212 return (SET_ERROR(ENOSPC));
2215 ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa));
2216 ASSERT(BP_GET_NDVAS(bp) == 0);
2217 ASSERT(hintbp == NULL || ndvas <= BP_GET_NDVAS(hintbp));
2219 for (int d = 0; d < ndvas; d++) {
2220 error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva,
2223 for (d--; d >= 0; d--) {
2224 metaslab_free_dva(spa, &dva[d], txg, B_TRUE);
2225 bzero(&dva[d], sizeof (dva_t));
2227 spa_config_exit(spa, SCL_ALLOC, FTAG);
2232 ASSERT(BP_GET_NDVAS(bp) == ndvas);
2234 spa_config_exit(spa, SCL_ALLOC, FTAG);
2236 BP_SET_BIRTH(bp, txg, txg);
2242 metaslab_free(spa_t *spa, const blkptr_t *bp, uint64_t txg, boolean_t now)
2244 const dva_t *dva = bp->blk_dva;
2245 int ndvas = BP_GET_NDVAS(bp);
2247 ASSERT(!BP_IS_HOLE(bp));
2248 ASSERT(!now || bp->blk_birth >= spa_syncing_txg(spa));
2250 spa_config_enter(spa, SCL_FREE, FTAG, RW_READER);
2252 for (int d = 0; d < ndvas; d++)
2253 metaslab_free_dva(spa, &dva[d], txg, now);
2255 spa_config_exit(spa, SCL_FREE, FTAG);
2259 metaslab_claim(spa_t *spa, const blkptr_t *bp, uint64_t txg)
2261 const dva_t *dva = bp->blk_dva;
2262 int ndvas = BP_GET_NDVAS(bp);
2265 ASSERT(!BP_IS_HOLE(bp));
2269 * First do a dry run to make sure all DVAs are claimable,
2270 * so we don't have to unwind from partial failures below.
2272 if ((error = metaslab_claim(spa, bp, 0)) != 0)
2276 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
2278 for (int d = 0; d < ndvas; d++)
2279 if ((error = metaslab_claim_dva(spa, &dva[d], txg)) != 0)
2282 spa_config_exit(spa, SCL_ALLOC, FTAG);
2284 ASSERT(error == 0 || txg == 0);
2290 metaslab_check_free(spa_t *spa, const blkptr_t *bp)
2292 if ((zfs_flags & ZFS_DEBUG_ZIO_FREE) == 0)
2295 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
2296 for (int i = 0; i < BP_GET_NDVAS(bp); i++) {
2297 uint64_t vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
2298 vdev_t *vd = vdev_lookup_top(spa, vdev);
2299 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]);
2300 uint64_t size = DVA_GET_ASIZE(&bp->blk_dva[i]);
2301 metaslab_t *msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
2304 range_tree_verify(msp->ms_tree, offset, size);
2306 for (int j = 0; j < TXG_SIZE; j++)
2307 range_tree_verify(msp->ms_freetree[j], offset, size);
2308 for (int j = 0; j < TXG_DEFER_SIZE; j++)
2309 range_tree_verify(msp->ms_defertree[j], offset, size);
2311 spa_config_exit(spa, SCL_VDEV, FTAG);