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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 * Copyright (c) 2012 by Delphix. All rights reserved.
29 #include <sys/zfs_context.h>
33 #include <sys/space_map.h>
35 static kmem_cache_t *space_seg_cache;
40 ASSERT(space_seg_cache == NULL);
41 space_seg_cache = kmem_cache_create("space_seg_cache",
42 sizeof (space_seg_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
48 kmem_cache_destroy(space_seg_cache);
49 space_seg_cache = NULL;
54 * NOTE: caller is responsible for all locking.
57 space_map_seg_compare(const void *x1, const void *x2)
59 const space_seg_t *s1 = x1;
60 const space_seg_t *s2 = x2;
62 if (s1->ss_start < s2->ss_start) {
63 if (s1->ss_end > s2->ss_start)
67 if (s1->ss_start > s2->ss_start) {
68 if (s1->ss_start < s2->ss_end)
76 space_map_create(space_map_t *sm, uint64_t start, uint64_t size, uint8_t shift,
79 bzero(sm, sizeof (*sm));
81 cv_init(&sm->sm_load_cv, NULL, CV_DEFAULT, NULL);
83 avl_create(&sm->sm_root, space_map_seg_compare,
84 sizeof (space_seg_t), offsetof(struct space_seg, ss_node));
93 space_map_destroy(space_map_t *sm)
95 ASSERT(!sm->sm_loaded && !sm->sm_loading);
96 VERIFY0(sm->sm_space);
97 avl_destroy(&sm->sm_root);
98 cv_destroy(&sm->sm_load_cv);
102 space_map_add(space_map_t *sm, uint64_t start, uint64_t size)
105 space_seg_t ssearch, *ss_before, *ss_after, *ss;
106 uint64_t end = start + size;
107 int merge_before, merge_after;
109 ASSERT(MUTEX_HELD(sm->sm_lock));
110 VERIFY(!sm->sm_condensing);
112 VERIFY3U(start, >=, sm->sm_start);
113 VERIFY3U(end, <=, sm->sm_start + sm->sm_size);
114 VERIFY(sm->sm_space + size <= sm->sm_size);
115 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
116 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
118 ssearch.ss_start = start;
119 ssearch.ss_end = end;
120 ss = avl_find(&sm->sm_root, &ssearch, &where);
122 if (ss != NULL && ss->ss_start <= start && ss->ss_end >= end) {
123 zfs_panic_recover("zfs: allocating allocated segment"
124 "(offset=%llu size=%llu)\n",
125 (longlong_t)start, (longlong_t)size);
129 /* Make sure we don't overlap with either of our neighbors */
132 ss_before = avl_nearest(&sm->sm_root, where, AVL_BEFORE);
133 ss_after = avl_nearest(&sm->sm_root, where, AVL_AFTER);
135 merge_before = (ss_before != NULL && ss_before->ss_end == start);
136 merge_after = (ss_after != NULL && ss_after->ss_start == end);
138 if (merge_before && merge_after) {
139 avl_remove(&sm->sm_root, ss_before);
140 if (sm->sm_pp_root) {
141 avl_remove(sm->sm_pp_root, ss_before);
142 avl_remove(sm->sm_pp_root, ss_after);
144 ss_after->ss_start = ss_before->ss_start;
145 kmem_cache_free(space_seg_cache, ss_before);
147 } else if (merge_before) {
148 ss_before->ss_end = end;
150 avl_remove(sm->sm_pp_root, ss_before);
152 } else if (merge_after) {
153 ss_after->ss_start = start;
155 avl_remove(sm->sm_pp_root, ss_after);
158 ss = kmem_cache_alloc(space_seg_cache, KM_SLEEP);
159 ss->ss_start = start;
161 avl_insert(&sm->sm_root, ss, where);
165 avl_add(sm->sm_pp_root, ss);
167 sm->sm_space += size;
171 space_map_remove(space_map_t *sm, uint64_t start, uint64_t size)
173 space_seg_t ssearch, *ss, *newseg;
174 uint64_t end = start + size;
175 int left_over, right_over;
177 ASSERT(MUTEX_HELD(sm->sm_lock));
178 VERIFY(!sm->sm_condensing);
180 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
181 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
183 ssearch.ss_start = start;
184 ssearch.ss_end = end;
185 ss = avl_find(&sm->sm_root, &ssearch, NULL);
187 /* Make sure we completely overlap with someone */
189 zfs_panic_recover("zfs: freeing free segment "
190 "(offset=%llu size=%llu)",
191 (longlong_t)start, (longlong_t)size);
194 VERIFY3U(ss->ss_start, <=, start);
195 VERIFY3U(ss->ss_end, >=, end);
196 VERIFY(sm->sm_space - size < sm->sm_size);
198 left_over = (ss->ss_start != start);
199 right_over = (ss->ss_end != end);
202 avl_remove(sm->sm_pp_root, ss);
204 if (left_over && right_over) {
205 newseg = kmem_cache_alloc(space_seg_cache, KM_SLEEP);
206 newseg->ss_start = end;
207 newseg->ss_end = ss->ss_end;
209 avl_insert_here(&sm->sm_root, newseg, ss, AVL_AFTER);
211 avl_add(sm->sm_pp_root, newseg);
212 } else if (left_over) {
214 } else if (right_over) {
217 avl_remove(&sm->sm_root, ss);
218 kmem_cache_free(space_seg_cache, ss);
222 if (sm->sm_pp_root && ss != NULL)
223 avl_add(sm->sm_pp_root, ss);
225 sm->sm_space -= size;
229 space_map_contains(space_map_t *sm, uint64_t start, uint64_t size)
232 space_seg_t ssearch, *ss;
233 uint64_t end = start + size;
235 ASSERT(MUTEX_HELD(sm->sm_lock));
237 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
238 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
240 ssearch.ss_start = start;
241 ssearch.ss_end = end;
242 ss = avl_find(&sm->sm_root, &ssearch, &where);
244 return (ss != NULL && ss->ss_start <= start && ss->ss_end >= end);
248 space_map_swap(space_map_t **msrc, space_map_t **mdst)
252 ASSERT(MUTEX_HELD((*msrc)->sm_lock));
253 ASSERT0((*mdst)->sm_space);
254 ASSERT0(avl_numnodes(&(*mdst)->sm_root));
262 space_map_vacate(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
267 ASSERT(MUTEX_HELD(sm->sm_lock));
269 while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) {
271 func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
272 kmem_cache_free(space_seg_cache, ss);
278 space_map_walk(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
282 ASSERT(MUTEX_HELD(sm->sm_lock));
284 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
285 func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
289 * Wait for any in-progress space_map_load() to complete.
292 space_map_load_wait(space_map_t *sm)
294 ASSERT(MUTEX_HELD(sm->sm_lock));
296 while (sm->sm_loading) {
297 ASSERT(!sm->sm_loaded);
298 cv_wait(&sm->sm_load_cv, sm->sm_lock);
303 * Note: space_map_load() will drop sm_lock across dmu_read() calls.
304 * The caller must be OK with this.
307 space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype,
308 space_map_obj_t *smo, objset_t *os)
310 uint64_t *entry, *entry_map, *entry_map_end;
311 uint64_t bufsize, size, offset, end, space;
312 uint64_t mapstart = sm->sm_start;
315 ASSERT(MUTEX_HELD(sm->sm_lock));
316 ASSERT(!sm->sm_loaded);
317 ASSERT(!sm->sm_loading);
319 sm->sm_loading = B_TRUE;
320 end = smo->smo_objsize;
321 space = smo->smo_alloc;
323 ASSERT(sm->sm_ops == NULL);
324 VERIFY0(sm->sm_space);
326 if (maptype == SM_FREE) {
327 space_map_add(sm, sm->sm_start, sm->sm_size);
328 space = sm->sm_size - space;
331 bufsize = 1ULL << SPACE_MAP_BLOCKSHIFT;
332 entry_map = zio_buf_alloc(bufsize);
334 mutex_exit(sm->sm_lock);
336 dmu_prefetch(os, smo->smo_object, bufsize, end - bufsize);
337 mutex_enter(sm->sm_lock);
339 for (offset = 0; offset < end; offset += bufsize) {
340 size = MIN(end - offset, bufsize);
341 VERIFY(P2PHASE(size, sizeof (uint64_t)) == 0);
344 dprintf("object=%llu offset=%llx size=%llx\n",
345 smo->smo_object, offset, size);
347 mutex_exit(sm->sm_lock);
348 error = dmu_read(os, smo->smo_object, offset, size, entry_map,
350 mutex_enter(sm->sm_lock);
354 entry_map_end = entry_map + (size / sizeof (uint64_t));
355 for (entry = entry_map; entry < entry_map_end; entry++) {
358 if (SM_DEBUG_DECODE(e)) /* Skip debug entries */
361 (SM_TYPE_DECODE(e) == maptype ?
362 space_map_add : space_map_remove)(sm,
363 (SM_OFFSET_DECODE(e) << sm->sm_shift) + mapstart,
364 SM_RUN_DECODE(e) << sm->sm_shift);
369 VERIFY3U(sm->sm_space, ==, space);
371 sm->sm_loaded = B_TRUE;
376 space_map_vacate(sm, NULL, NULL);
379 zio_buf_free(entry_map, bufsize);
381 sm->sm_loading = B_FALSE;
383 cv_broadcast(&sm->sm_load_cv);
389 space_map_unload(space_map_t *sm)
391 ASSERT(MUTEX_HELD(sm->sm_lock));
393 if (sm->sm_loaded && sm->sm_ops != NULL)
394 sm->sm_ops->smop_unload(sm);
396 sm->sm_loaded = B_FALSE;
399 space_map_vacate(sm, NULL, NULL);
403 space_map_maxsize(space_map_t *sm)
405 ASSERT(sm->sm_ops != NULL);
406 return (sm->sm_ops->smop_max(sm));
410 space_map_alloc(space_map_t *sm, uint64_t size)
414 start = sm->sm_ops->smop_alloc(sm, size);
416 space_map_remove(sm, start, size);
421 space_map_claim(space_map_t *sm, uint64_t start, uint64_t size)
423 sm->sm_ops->smop_claim(sm, start, size);
424 space_map_remove(sm, start, size);
428 space_map_free(space_map_t *sm, uint64_t start, uint64_t size)
430 space_map_add(sm, start, size);
431 sm->sm_ops->smop_free(sm, start, size);
435 * Note: space_map_sync() will drop sm_lock across dmu_write() calls.
438 space_map_sync(space_map_t *sm, uint8_t maptype,
439 space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
441 spa_t *spa = dmu_objset_spa(os);
442 avl_tree_t *t = &sm->sm_root;
444 uint64_t bufsize, start, size, run_len, total, sm_space, nodes;
445 uint64_t *entry, *entry_map, *entry_map_end;
447 ASSERT(MUTEX_HELD(sm->sm_lock));
449 if (sm->sm_space == 0)
452 dprintf("object %4llu, txg %llu, pass %d, %c, count %lu, space %llx\n",
453 smo->smo_object, dmu_tx_get_txg(tx), spa_sync_pass(spa),
454 maptype == SM_ALLOC ? 'A' : 'F', avl_numnodes(&sm->sm_root),
457 if (maptype == SM_ALLOC)
458 smo->smo_alloc += sm->sm_space;
460 smo->smo_alloc -= sm->sm_space;
462 bufsize = (8 + avl_numnodes(&sm->sm_root)) * sizeof (uint64_t);
463 bufsize = MIN(bufsize, 1ULL << SPACE_MAP_BLOCKSHIFT);
464 entry_map = zio_buf_alloc(bufsize);
465 entry_map_end = entry_map + (bufsize / sizeof (uint64_t));
468 *entry++ = SM_DEBUG_ENCODE(1) |
469 SM_DEBUG_ACTION_ENCODE(maptype) |
470 SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa)) |
471 SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx));
474 nodes = avl_numnodes(&sm->sm_root);
475 sm_space = sm->sm_space;
476 for (ss = avl_first(t); ss != NULL; ss = AVL_NEXT(t, ss)) {
477 size = ss->ss_end - ss->ss_start;
478 start = (ss->ss_start - sm->sm_start) >> sm->sm_shift;
481 size >>= sm->sm_shift;
484 run_len = MIN(size, SM_RUN_MAX);
486 if (entry == entry_map_end) {
487 mutex_exit(sm->sm_lock);
488 dmu_write(os, smo->smo_object, smo->smo_objsize,
489 bufsize, entry_map, tx);
490 mutex_enter(sm->sm_lock);
491 smo->smo_objsize += bufsize;
495 *entry++ = SM_OFFSET_ENCODE(start) |
496 SM_TYPE_ENCODE(maptype) |
497 SM_RUN_ENCODE(run_len);
504 if (entry != entry_map) {
505 size = (entry - entry_map) * sizeof (uint64_t);
506 mutex_exit(sm->sm_lock);
507 dmu_write(os, smo->smo_object, smo->smo_objsize,
508 size, entry_map, tx);
509 mutex_enter(sm->sm_lock);
510 smo->smo_objsize += size;
514 * Ensure that the space_map's accounting wasn't changed
515 * while we were in the middle of writing it out.
517 VERIFY3U(nodes, ==, avl_numnodes(&sm->sm_root));
518 VERIFY3U(sm->sm_space, ==, sm_space);
519 VERIFY3U(sm->sm_space, ==, total);
521 zio_buf_free(entry_map, bufsize);
525 space_map_truncate(space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
527 VERIFY(dmu_free_range(os, smo->smo_object, 0, -1ULL, tx) == 0);
529 smo->smo_objsize = 0;
534 * Space map reference trees.
536 * A space map is a collection of integers. Every integer is either
537 * in the map, or it's not. A space map reference tree generalizes
538 * the idea: it allows its members to have arbitrary reference counts,
539 * as opposed to the implicit reference count of 0 or 1 in a space map.
540 * This representation comes in handy when computing the union or
541 * intersection of multiple space maps. For example, the union of
542 * N space maps is the subset of the reference tree with refcnt >= 1.
543 * The intersection of N space maps is the subset with refcnt >= N.
545 * [It's very much like a Fourier transform. Unions and intersections
546 * are hard to perform in the 'space map domain', so we convert the maps
547 * into the 'reference count domain', where it's trivial, then invert.]
549 * vdev_dtl_reassess() uses computations of this form to determine
550 * DTL_MISSING and DTL_OUTAGE for interior vdevs -- e.g. a RAID-Z vdev
551 * has an outage wherever refcnt >= vdev_nparity + 1, and a mirror vdev
552 * has an outage wherever refcnt >= vdev_children.
555 space_map_ref_compare(const void *x1, const void *x2)
557 const space_ref_t *sr1 = x1;
558 const space_ref_t *sr2 = x2;
560 if (sr1->sr_offset < sr2->sr_offset)
562 if (sr1->sr_offset > sr2->sr_offset)
574 space_map_ref_create(avl_tree_t *t)
576 avl_create(t, space_map_ref_compare,
577 sizeof (space_ref_t), offsetof(space_ref_t, sr_node));
581 space_map_ref_destroy(avl_tree_t *t)
586 while ((sr = avl_destroy_nodes(t, &cookie)) != NULL)
587 kmem_free(sr, sizeof (*sr));
593 space_map_ref_add_node(avl_tree_t *t, uint64_t offset, int64_t refcnt)
597 sr = kmem_alloc(sizeof (*sr), KM_SLEEP);
598 sr->sr_offset = offset;
599 sr->sr_refcnt = refcnt;
605 space_map_ref_add_seg(avl_tree_t *t, uint64_t start, uint64_t end,
608 space_map_ref_add_node(t, start, refcnt);
609 space_map_ref_add_node(t, end, -refcnt);
613 * Convert (or add) a space map into a reference tree.
616 space_map_ref_add_map(avl_tree_t *t, space_map_t *sm, int64_t refcnt)
620 ASSERT(MUTEX_HELD(sm->sm_lock));
622 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
623 space_map_ref_add_seg(t, ss->ss_start, ss->ss_end, refcnt);
627 * Convert a reference tree into a space map. The space map will contain
628 * all members of the reference tree for which refcnt >= minref.
631 space_map_ref_generate_map(avl_tree_t *t, space_map_t *sm, int64_t minref)
633 uint64_t start = -1ULL;
637 ASSERT(MUTEX_HELD(sm->sm_lock));
639 space_map_vacate(sm, NULL, NULL);
641 for (sr = avl_first(t); sr != NULL; sr = AVL_NEXT(t, sr)) {
642 refcnt += sr->sr_refcnt;
643 if (refcnt >= minref) {
644 if (start == -1ULL) {
645 start = sr->sr_offset;
648 if (start != -1ULL) {
649 uint64_t end = sr->sr_offset;
650 ASSERT(start <= end);
652 space_map_add(sm, start, end - start);
658 ASSERT(start == -1ULL);