1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 * 25 */ 26 27 /* 28 * Copyright (c) 2012 by Delphix. All rights reserved. 29 */ 30 31 #include <sys/zfs_context.h> 32 #include <sys/spa.h> 33 #include <sys/dmu.h> 34 #include <sys/zio.h> 35 #include <sys/space_map.h> 36 37 /* 38 * Space map routines. 39 * NOTE: caller is responsible for all locking. 40 */ 41 static int 42 space_map_seg_compare(const void *x1, const void *x2) 43 { 44 const space_seg_t *s1 = x1; 45 const space_seg_t *s2 = x2; 46 47 if (s1->ss_start < s2->ss_start) { 48 if (s1->ss_end > s2->ss_start) 49 return (0); 50 return (-1); 51 } 52 if (s1->ss_start > s2->ss_start) { 53 if (s1->ss_start < s2->ss_end) 54 return (0); 55 return (1); 56 } 57 return (0); 58 } 59 60 void 61 space_map_create(space_map_t *sm, uint64_t start, uint64_t size, uint8_t shift, 62 kmutex_t *lp) 63 { 64 bzero(sm, sizeof (*sm)); 65 66 cv_init(&sm->sm_load_cv, NULL, CV_DEFAULT, NULL); 67 68 avl_create(&sm->sm_root, space_map_seg_compare, 69 sizeof (space_seg_t), offsetof(struct space_seg, ss_node)); 70 71 sm->sm_start = start; 72 sm->sm_size = size; 73 sm->sm_shift = shift; 74 sm->sm_lock = lp; 75 } 76 77 void 78 space_map_destroy(space_map_t *sm) 79 { 80 ASSERT(!sm->sm_loaded && !sm->sm_loading); 81 VERIFY0(sm->sm_space); 82 avl_destroy(&sm->sm_root); 83 cv_destroy(&sm->sm_load_cv); 84 } 85 86 void 87 space_map_add(space_map_t *sm, uint64_t start, uint64_t size) 88 { 89 avl_index_t where; 90 space_seg_t ssearch, *ss_before, *ss_after, *ss; 91 uint64_t end = start + size; 92 int merge_before, merge_after; 93 94 ASSERT(MUTEX_HELD(sm->sm_lock)); 95 VERIFY(size != 0); 96 VERIFY3U(start, >=, sm->sm_start); 97 VERIFY3U(end, <=, sm->sm_start + sm->sm_size); 98 VERIFY(sm->sm_space + size <= sm->sm_size); 99 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0); 100 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0); 101 102 ssearch.ss_start = start; 103 ssearch.ss_end = end; 104 ss = avl_find(&sm->sm_root, &ssearch, &where); 105 106 if (ss != NULL && ss->ss_start <= start && ss->ss_end >= end) { 107 zfs_panic_recover("zfs: allocating allocated segment" 108 "(offset=%llu size=%llu)\n", 109 (longlong_t)start, (longlong_t)size); 110 return; 111 } 112 113 /* Make sure we don't overlap with either of our neighbors */ 114 VERIFY(ss == NULL); 115 116 ss_before = avl_nearest(&sm->sm_root, where, AVL_BEFORE); 117 ss_after = avl_nearest(&sm->sm_root, where, AVL_AFTER); 118 119 merge_before = (ss_before != NULL && ss_before->ss_end == start); 120 merge_after = (ss_after != NULL && ss_after->ss_start == end); 121 122 if (merge_before && merge_after) { 123 avl_remove(&sm->sm_root, ss_before); 124 if (sm->sm_pp_root) { 125 avl_remove(sm->sm_pp_root, ss_before); 126 avl_remove(sm->sm_pp_root, ss_after); 127 } 128 ss_after->ss_start = ss_before->ss_start; 129 kmem_free(ss_before, sizeof (*ss_before)); 130 ss = ss_after; 131 } else if (merge_before) { 132 ss_before->ss_end = end; 133 if (sm->sm_pp_root) 134 avl_remove(sm->sm_pp_root, ss_before); 135 ss = ss_before; 136 } else if (merge_after) { 137 ss_after->ss_start = start; 138 if (sm->sm_pp_root) 139 avl_remove(sm->sm_pp_root, ss_after); 140 ss = ss_after; 141 } else { 142 ss = kmem_alloc(sizeof (*ss), KM_SLEEP); 143 ss->ss_start = start; 144 ss->ss_end = end; 145 avl_insert(&sm->sm_root, ss, where); 146 } 147 148 if (sm->sm_pp_root) 149 avl_add(sm->sm_pp_root, ss); 150 151 sm->sm_space += size; 152 } 153 154 void 155 space_map_remove(space_map_t *sm, uint64_t start, uint64_t size) 156 { 157 avl_index_t where; 158 space_seg_t ssearch, *ss, *newseg; 159 uint64_t end = start + size; 160 int left_over, right_over; 161 162 ASSERT(MUTEX_HELD(sm->sm_lock)); 163 VERIFY(size != 0); 164 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0); 165 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0); 166 167 ssearch.ss_start = start; 168 ssearch.ss_end = end; 169 ss = avl_find(&sm->sm_root, &ssearch, &where); 170 171 /* Make sure we completely overlap with someone */ 172 if (ss == NULL) { 173 zfs_panic_recover("zfs: freeing free segment " 174 "(offset=%llu size=%llu)", 175 (longlong_t)start, (longlong_t)size); 176 return; 177 } 178 VERIFY3U(ss->ss_start, <=, start); 179 VERIFY3U(ss->ss_end, >=, end); 180 VERIFY(sm->sm_space - size <= sm->sm_size); 181 182 left_over = (ss->ss_start != start); 183 right_over = (ss->ss_end != end); 184 185 if (sm->sm_pp_root) 186 avl_remove(sm->sm_pp_root, ss); 187 188 if (left_over && right_over) { 189 newseg = kmem_alloc(sizeof (*newseg), KM_SLEEP); 190 newseg->ss_start = end; 191 newseg->ss_end = ss->ss_end; 192 ss->ss_end = start; 193 avl_insert_here(&sm->sm_root, newseg, ss, AVL_AFTER); 194 if (sm->sm_pp_root) 195 avl_add(sm->sm_pp_root, newseg); 196 } else if (left_over) { 197 ss->ss_end = start; 198 } else if (right_over) { 199 ss->ss_start = end; 200 } else { 201 avl_remove(&sm->sm_root, ss); 202 kmem_free(ss, sizeof (*ss)); 203 ss = NULL; 204 } 205 206 if (sm->sm_pp_root && ss != NULL) 207 avl_add(sm->sm_pp_root, ss); 208 209 sm->sm_space -= size; 210 } 211 212 boolean_t 213 space_map_contains(space_map_t *sm, uint64_t start, uint64_t size) 214 { 215 avl_index_t where; 216 space_seg_t ssearch, *ss; 217 uint64_t end = start + size; 218 219 ASSERT(MUTEX_HELD(sm->sm_lock)); 220 VERIFY(size != 0); 221 VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0); 222 VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0); 223 224 ssearch.ss_start = start; 225 ssearch.ss_end = end; 226 ss = avl_find(&sm->sm_root, &ssearch, &where); 227 228 return (ss != NULL && ss->ss_start <= start && ss->ss_end >= end); 229 } 230 231 void 232 space_map_vacate(space_map_t *sm, space_map_func_t *func, space_map_t *mdest) 233 { 234 space_seg_t *ss; 235 void *cookie = NULL; 236 237 ASSERT(MUTEX_HELD(sm->sm_lock)); 238 239 while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) { 240 if (func != NULL) 241 func(mdest, ss->ss_start, ss->ss_end - ss->ss_start); 242 kmem_free(ss, sizeof (*ss)); 243 } 244 sm->sm_space = 0; 245 } 246 247 void 248 space_map_walk(space_map_t *sm, space_map_func_t *func, space_map_t *mdest) 249 { 250 space_seg_t *ss; 251 252 ASSERT(MUTEX_HELD(sm->sm_lock)); 253 254 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss)) 255 func(mdest, ss->ss_start, ss->ss_end - ss->ss_start); 256 } 257 258 /* 259 * Wait for any in-progress space_map_load() to complete. 260 */ 261 void 262 space_map_load_wait(space_map_t *sm) 263 { 264 ASSERT(MUTEX_HELD(sm->sm_lock)); 265 266 while (sm->sm_loading) { 267 ASSERT(!sm->sm_loaded); 268 cv_wait(&sm->sm_load_cv, sm->sm_lock); 269 } 270 } 271 272 /* 273 * Note: space_map_load() will drop sm_lock across dmu_read() calls. 274 * The caller must be OK with this. 275 */ 276 int 277 space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype, 278 space_map_obj_t *smo, objset_t *os) 279 { 280 uint64_t *entry, *entry_map, *entry_map_end; 281 uint64_t bufsize, size, offset, end, space; 282 uint64_t mapstart = sm->sm_start; 283 int error = 0; 284 285 ASSERT(MUTEX_HELD(sm->sm_lock)); 286 ASSERT(!sm->sm_loaded); 287 ASSERT(!sm->sm_loading); 288 289 sm->sm_loading = B_TRUE; 290 end = smo->smo_objsize; 291 space = smo->smo_alloc; 292 293 ASSERT(sm->sm_ops == NULL); 294 VERIFY0(sm->sm_space); 295 296 if (maptype == SM_FREE) { 297 space_map_add(sm, sm->sm_start, sm->sm_size); 298 space = sm->sm_size - space; 299 } 300 301 bufsize = 1ULL << SPACE_MAP_BLOCKSHIFT; 302 entry_map = zio_buf_alloc(bufsize); 303 304 mutex_exit(sm->sm_lock); 305 if (end > bufsize) 306 dmu_prefetch(os, smo->smo_object, bufsize, end - bufsize); 307 mutex_enter(sm->sm_lock); 308 309 for (offset = 0; offset < end; offset += bufsize) { 310 size = MIN(end - offset, bufsize); 311 VERIFY(P2PHASE(size, sizeof (uint64_t)) == 0); 312 VERIFY(size != 0); 313 314 dprintf("object=%llu offset=%llx size=%llx\n", 315 smo->smo_object, offset, size); 316 317 mutex_exit(sm->sm_lock); 318 error = dmu_read(os, smo->smo_object, offset, size, entry_map, 319 DMU_READ_PREFETCH); 320 mutex_enter(sm->sm_lock); 321 if (error != 0) 322 break; 323 324 entry_map_end = entry_map + (size / sizeof (uint64_t)); 325 for (entry = entry_map; entry < entry_map_end; entry++) { 326 uint64_t e = *entry; 327 328 if (SM_DEBUG_DECODE(e)) /* Skip debug entries */ 329 continue; 330 331 (SM_TYPE_DECODE(e) == maptype ? 332 space_map_add : space_map_remove)(sm, 333 (SM_OFFSET_DECODE(e) << sm->sm_shift) + mapstart, 334 SM_RUN_DECODE(e) << sm->sm_shift); 335 } 336 } 337 338 if (error == 0) { 339 VERIFY3U(sm->sm_space, ==, space); 340 341 sm->sm_loaded = B_TRUE; 342 sm->sm_ops = ops; 343 if (ops != NULL) 344 ops->smop_load(sm); 345 } else { 346 space_map_vacate(sm, NULL, NULL); 347 } 348 349 zio_buf_free(entry_map, bufsize); 350 351 sm->sm_loading = B_FALSE; 352 353 cv_broadcast(&sm->sm_load_cv); 354 355 return (error); 356 } 357 358 void 359 space_map_unload(space_map_t *sm) 360 { 361 ASSERT(MUTEX_HELD(sm->sm_lock)); 362 363 if (sm->sm_loaded && sm->sm_ops != NULL) 364 sm->sm_ops->smop_unload(sm); 365 366 sm->sm_loaded = B_FALSE; 367 sm->sm_ops = NULL; 368 369 space_map_vacate(sm, NULL, NULL); 370 } 371 372 uint64_t 373 space_map_maxsize(space_map_t *sm) 374 { 375 ASSERT(sm->sm_ops != NULL); 376 return (sm->sm_ops->smop_max(sm)); 377 } 378 379 uint64_t 380 space_map_alloc(space_map_t *sm, uint64_t size) 381 { 382 uint64_t start; 383 384 start = sm->sm_ops->smop_alloc(sm, size); 385 if (start != -1ULL) 386 space_map_remove(sm, start, size); 387 return (start); 388 } 389 390 void 391 space_map_claim(space_map_t *sm, uint64_t start, uint64_t size) 392 { 393 sm->sm_ops->smop_claim(sm, start, size); 394 space_map_remove(sm, start, size); 395 } 396 397 void 398 space_map_free(space_map_t *sm, uint64_t start, uint64_t size) 399 { 400 space_map_add(sm, start, size); 401 sm->sm_ops->smop_free(sm, start, size); 402 } 403 404 /* 405 * Note: space_map_sync() will drop sm_lock across dmu_write() calls. 406 */ 407 void 408 space_map_sync(space_map_t *sm, uint8_t maptype, 409 space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx) 410 { 411 spa_t *spa = dmu_objset_spa(os); 412 void *cookie = NULL; 413 space_seg_t *ss; 414 uint64_t bufsize, start, size, run_len; 415 uint64_t *entry, *entry_map, *entry_map_end; 416 417 ASSERT(MUTEX_HELD(sm->sm_lock)); 418 419 if (sm->sm_space == 0) 420 return; 421 422 dprintf("object %4llu, txg %llu, pass %d, %c, count %lu, space %llx\n", 423 smo->smo_object, dmu_tx_get_txg(tx), spa_sync_pass(spa), 424 maptype == SM_ALLOC ? 'A' : 'F', avl_numnodes(&sm->sm_root), 425 sm->sm_space); 426 427 if (maptype == SM_ALLOC) 428 smo->smo_alloc += sm->sm_space; 429 else 430 smo->smo_alloc -= sm->sm_space; 431 432 bufsize = (8 + avl_numnodes(&sm->sm_root)) * sizeof (uint64_t); 433 bufsize = MIN(bufsize, 1ULL << SPACE_MAP_BLOCKSHIFT); 434 entry_map = zio_buf_alloc(bufsize); 435 entry_map_end = entry_map + (bufsize / sizeof (uint64_t)); 436 entry = entry_map; 437 438 *entry++ = SM_DEBUG_ENCODE(1) | 439 SM_DEBUG_ACTION_ENCODE(maptype) | 440 SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa)) | 441 SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx)); 442 443 while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) { 444 size = ss->ss_end - ss->ss_start; 445 start = (ss->ss_start - sm->sm_start) >> sm->sm_shift; 446 447 sm->sm_space -= size; 448 size >>= sm->sm_shift; 449 450 while (size) { 451 run_len = MIN(size, SM_RUN_MAX); 452 453 if (entry == entry_map_end) { 454 mutex_exit(sm->sm_lock); 455 dmu_write(os, smo->smo_object, smo->smo_objsize, 456 bufsize, entry_map, tx); 457 mutex_enter(sm->sm_lock); 458 smo->smo_objsize += bufsize; 459 entry = entry_map; 460 } 461 462 *entry++ = SM_OFFSET_ENCODE(start) | 463 SM_TYPE_ENCODE(maptype) | 464 SM_RUN_ENCODE(run_len); 465 466 start += run_len; 467 size -= run_len; 468 } 469 kmem_free(ss, sizeof (*ss)); 470 } 471 472 if (entry != entry_map) { 473 size = (entry - entry_map) * sizeof (uint64_t); 474 mutex_exit(sm->sm_lock); 475 dmu_write(os, smo->smo_object, smo->smo_objsize, 476 size, entry_map, tx); 477 mutex_enter(sm->sm_lock); 478 smo->smo_objsize += size; 479 } 480 481 zio_buf_free(entry_map, bufsize); 482 483 VERIFY0(sm->sm_space); 484 } 485 486 void 487 space_map_truncate(space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx) 488 { 489 VERIFY(dmu_free_range(os, smo->smo_object, 0, -1ULL, tx) == 0); 490 491 smo->smo_objsize = 0; 492 smo->smo_alloc = 0; 493 } 494 495 /* 496 * Space map reference trees. 497 * 498 * A space map is a collection of integers. Every integer is either 499 * in the map, or it's not. A space map reference tree generalizes 500 * the idea: it allows its members to have arbitrary reference counts, 501 * as opposed to the implicit reference count of 0 or 1 in a space map. 502 * This representation comes in handy when computing the union or 503 * intersection of multiple space maps. For example, the union of 504 * N space maps is the subset of the reference tree with refcnt >= 1. 505 * The intersection of N space maps is the subset with refcnt >= N. 506 * 507 * [It's very much like a Fourier transform. Unions and intersections 508 * are hard to perform in the 'space map domain', so we convert the maps 509 * into the 'reference count domain', where it's trivial, then invert.] 510 * 511 * vdev_dtl_reassess() uses computations of this form to determine 512 * DTL_MISSING and DTL_OUTAGE for interior vdevs -- e.g. a RAID-Z vdev 513 * has an outage wherever refcnt >= vdev_nparity + 1, and a mirror vdev 514 * has an outage wherever refcnt >= vdev_children. 515 */ 516 static int 517 space_map_ref_compare(const void *x1, const void *x2) 518 { 519 const space_ref_t *sr1 = x1; 520 const space_ref_t *sr2 = x2; 521 522 if (sr1->sr_offset < sr2->sr_offset) 523 return (-1); 524 if (sr1->sr_offset > sr2->sr_offset) 525 return (1); 526 527 if (sr1 < sr2) 528 return (-1); 529 if (sr1 > sr2) 530 return (1); 531 532 return (0); 533 } 534 535 void 536 space_map_ref_create(avl_tree_t *t) 537 { 538 avl_create(t, space_map_ref_compare, 539 sizeof (space_ref_t), offsetof(space_ref_t, sr_node)); 540 } 541 542 void 543 space_map_ref_destroy(avl_tree_t *t) 544 { 545 space_ref_t *sr; 546 void *cookie = NULL; 547 548 while ((sr = avl_destroy_nodes(t, &cookie)) != NULL) 549 kmem_free(sr, sizeof (*sr)); 550 551 avl_destroy(t); 552 } 553 554 static void 555 space_map_ref_add_node(avl_tree_t *t, uint64_t offset, int64_t refcnt) 556 { 557 space_ref_t *sr; 558 559 sr = kmem_alloc(sizeof (*sr), KM_SLEEP); 560 sr->sr_offset = offset; 561 sr->sr_refcnt = refcnt; 562 563 avl_add(t, sr); 564 } 565 566 void 567 space_map_ref_add_seg(avl_tree_t *t, uint64_t start, uint64_t end, 568 int64_t refcnt) 569 { 570 space_map_ref_add_node(t, start, refcnt); 571 space_map_ref_add_node(t, end, -refcnt); 572 } 573 574 /* 575 * Convert (or add) a space map into a reference tree. 576 */ 577 void 578 space_map_ref_add_map(avl_tree_t *t, space_map_t *sm, int64_t refcnt) 579 { 580 space_seg_t *ss; 581 582 ASSERT(MUTEX_HELD(sm->sm_lock)); 583 584 for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss)) 585 space_map_ref_add_seg(t, ss->ss_start, ss->ss_end, refcnt); 586 } 587 588 /* 589 * Convert a reference tree into a space map. The space map will contain 590 * all members of the reference tree for which refcnt >= minref. 591 */ 592 void 593 space_map_ref_generate_map(avl_tree_t *t, space_map_t *sm, int64_t minref) 594 { 595 uint64_t start = -1ULL; 596 int64_t refcnt = 0; 597 space_ref_t *sr; 598 599 ASSERT(MUTEX_HELD(sm->sm_lock)); 600 601 space_map_vacate(sm, NULL, NULL); 602 603 for (sr = avl_first(t); sr != NULL; sr = AVL_NEXT(t, sr)) { 604 refcnt += sr->sr_refcnt; 605 if (refcnt >= minref) { 606 if (start == -1ULL) { 607 start = sr->sr_offset; 608 } 609 } else { 610 if (start != -1ULL) { 611 uint64_t end = sr->sr_offset; 612 ASSERT(start <= end); 613 if (end > start) 614 space_map_add(sm, start, end - start); 615 start = -1ULL; 616 } 617 } 618 } 619 ASSERT(refcnt == 0); 620 ASSERT(start == -1ULL); 621 } 622