1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved. 24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. 25 */ 26 27 #include <sys/zfs_context.h> 28 #include <sys/dmu.h> 29 #include <sys/dmu_tx.h> 30 #include <sys/space_map.h> 31 #include <sys/metaslab_impl.h> 32 #include <sys/vdev_impl.h> 33 #include <sys/zio.h> 34 #include <sys/spa_impl.h> 35 36 /* 37 * Allow allocations to switch to gang blocks quickly. We do this to 38 * avoid having to load lots of space_maps in a given txg. There are, 39 * however, some cases where we want to avoid "fast" ganging and instead 40 * we want to do an exhaustive search of all metaslabs on this device. 41 * Currently we don't allow any gang, slog, or dump device related allocations 42 * to "fast" gang. 43 */ 44 #define CAN_FASTGANG(flags) \ 45 (!((flags) & (METASLAB_GANG_CHILD | METASLAB_GANG_HEADER | \ 46 METASLAB_GANG_AVOID))) 47 48 #define METASLAB_WEIGHT_PRIMARY (1ULL << 63) 49 #define METASLAB_WEIGHT_SECONDARY (1ULL << 62) 50 #define METASLAB_ACTIVE_MASK \ 51 (METASLAB_WEIGHT_PRIMARY | METASLAB_WEIGHT_SECONDARY) 52 53 uint64_t metaslab_aliquot = 512ULL << 10; 54 uint64_t metaslab_gang_bang = SPA_MAXBLOCKSIZE + 1; /* force gang blocks */ 55 56 /* 57 * The in-core space map representation is more compact than its on-disk form. 58 * The zfs_condense_pct determines how much more compact the in-core 59 * space_map representation must be before we compact it on-disk. 60 * Values should be greater than or equal to 100. 61 */ 62 int zfs_condense_pct = 200; 63 64 /* 65 * The zfs_mg_noalloc_threshold defines which metaslab groups should 66 * be eligible for allocation. The value is defined as a percentage of 67 * a free space. Metaslab groups that have more free space than 68 * zfs_mg_noalloc_threshold are always eligible for allocations. Once 69 * a metaslab group's free space is less than or equal to the 70 * zfs_mg_noalloc_threshold the allocator will avoid allocating to that 71 * group unless all groups in the pool have reached zfs_mg_noalloc_threshold. 72 * Once all groups in the pool reach zfs_mg_noalloc_threshold then all 73 * groups are allowed to accept allocations. Gang blocks are always 74 * eligible to allocate on any metaslab group. The default value of 0 means 75 * no metaslab group will be excluded based on this criterion. 76 */ 77 int zfs_mg_noalloc_threshold = 0; 78 79 /* 80 * When set will load all metaslabs when pool is first opened. 81 */ 82 int metaslab_debug_load = 0; 83 84 /* 85 * When set will prevent metaslabs from being unloaded. 86 */ 87 int metaslab_debug_unload = 0; 88 89 /* 90 * Minimum size which forces the dynamic allocator to change 91 * it's allocation strategy. Once the space map cannot satisfy 92 * an allocation of this size then it switches to using more 93 * aggressive strategy (i.e search by size rather than offset). 94 */ 95 uint64_t metaslab_df_alloc_threshold = SPA_MAXBLOCKSIZE; 96 97 /* 98 * The minimum free space, in percent, which must be available 99 * in a space map to continue allocations in a first-fit fashion. 100 * Once the space_map's free space drops below this level we dynamically 101 * switch to using best-fit allocations. 102 */ 103 int metaslab_df_free_pct = 4; 104 105 /* 106 * A metaslab is considered "free" if it contains a contiguous 107 * segment which is greater than metaslab_min_alloc_size. 108 */ 109 uint64_t metaslab_min_alloc_size = DMU_MAX_ACCESS; 110 111 /* 112 * Percentage of all cpus that can be used by the metaslab taskq. 113 */ 114 int metaslab_load_pct = 50; 115 116 /* 117 * Determines how many txgs a metaslab may remain loaded without having any 118 * allocations from it. As long as a metaslab continues to be used we will 119 * keep it loaded. 120 */ 121 int metaslab_unload_delay = TXG_SIZE * 2; 122 123 /* 124 * Should we be willing to write data to degraded vdevs? 125 */ 126 boolean_t zfs_write_to_degraded = B_FALSE; 127 128 /* 129 * Max number of metaslabs per group to preload. 130 */ 131 int metaslab_preload_limit = SPA_DVAS_PER_BP; 132 133 /* 134 * Enable/disable preloading of metaslab. 135 */ 136 boolean_t metaslab_preload_enabled = B_TRUE; 137 138 /* 139 * Enable/disable additional weight factor for each metaslab. 140 */ 141 boolean_t metaslab_weight_factor_enable = B_FALSE; 142 143 144 /* 145 * ========================================================================== 146 * Metaslab classes 147 * ========================================================================== 148 */ 149 metaslab_class_t * 150 metaslab_class_create(spa_t *spa, metaslab_ops_t *ops) 151 { 152 metaslab_class_t *mc; 153 154 mc = kmem_zalloc(sizeof (metaslab_class_t), KM_SLEEP); 155 156 mc->mc_spa = spa; 157 mc->mc_rotor = NULL; 158 mc->mc_ops = ops; 159 160 return (mc); 161 } 162 163 void 164 metaslab_class_destroy(metaslab_class_t *mc) 165 { 166 ASSERT(mc->mc_rotor == NULL); 167 ASSERT(mc->mc_alloc == 0); 168 ASSERT(mc->mc_deferred == 0); 169 ASSERT(mc->mc_space == 0); 170 ASSERT(mc->mc_dspace == 0); 171 172 kmem_free(mc, sizeof (metaslab_class_t)); 173 } 174 175 int 176 metaslab_class_validate(metaslab_class_t *mc) 177 { 178 metaslab_group_t *mg; 179 vdev_t *vd; 180 181 /* 182 * Must hold one of the spa_config locks. 183 */ 184 ASSERT(spa_config_held(mc->mc_spa, SCL_ALL, RW_READER) || 185 spa_config_held(mc->mc_spa, SCL_ALL, RW_WRITER)); 186 187 if ((mg = mc->mc_rotor) == NULL) 188 return (0); 189 190 do { 191 vd = mg->mg_vd; 192 ASSERT(vd->vdev_mg != NULL); 193 ASSERT3P(vd->vdev_top, ==, vd); 194 ASSERT3P(mg->mg_class, ==, mc); 195 ASSERT3P(vd->vdev_ops, !=, &vdev_hole_ops); 196 } while ((mg = mg->mg_next) != mc->mc_rotor); 197 198 return (0); 199 } 200 201 void 202 metaslab_class_space_update(metaslab_class_t *mc, int64_t alloc_delta, 203 int64_t defer_delta, int64_t space_delta, int64_t dspace_delta) 204 { 205 atomic_add_64(&mc->mc_alloc, alloc_delta); 206 atomic_add_64(&mc->mc_deferred, defer_delta); 207 atomic_add_64(&mc->mc_space, space_delta); 208 atomic_add_64(&mc->mc_dspace, dspace_delta); 209 } 210 211 uint64_t 212 metaslab_class_get_alloc(metaslab_class_t *mc) 213 { 214 return (mc->mc_alloc); 215 } 216 217 uint64_t 218 metaslab_class_get_deferred(metaslab_class_t *mc) 219 { 220 return (mc->mc_deferred); 221 } 222 223 uint64_t 224 metaslab_class_get_space(metaslab_class_t *mc) 225 { 226 return (mc->mc_space); 227 } 228 229 uint64_t 230 metaslab_class_get_dspace(metaslab_class_t *mc) 231 { 232 return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space); 233 } 234 235 /* 236 * ========================================================================== 237 * Metaslab groups 238 * ========================================================================== 239 */ 240 static int 241 metaslab_compare(const void *x1, const void *x2) 242 { 243 const metaslab_t *m1 = x1; 244 const metaslab_t *m2 = x2; 245 246 if (m1->ms_weight < m2->ms_weight) 247 return (1); 248 if (m1->ms_weight > m2->ms_weight) 249 return (-1); 250 251 /* 252 * If the weights are identical, use the offset to force uniqueness. 253 */ 254 if (m1->ms_start < m2->ms_start) 255 return (-1); 256 if (m1->ms_start > m2->ms_start) 257 return (1); 258 259 ASSERT3P(m1, ==, m2); 260 261 return (0); 262 } 263 264 /* 265 * Update the allocatable flag and the metaslab group's capacity. 266 * The allocatable flag is set to true if the capacity is below 267 * the zfs_mg_noalloc_threshold. If a metaslab group transitions 268 * from allocatable to non-allocatable or vice versa then the metaslab 269 * group's class is updated to reflect the transition. 270 */ 271 static void 272 metaslab_group_alloc_update(metaslab_group_t *mg) 273 { 274 vdev_t *vd = mg->mg_vd; 275 metaslab_class_t *mc = mg->mg_class; 276 vdev_stat_t *vs = &vd->vdev_stat; 277 boolean_t was_allocatable; 278 279 ASSERT(vd == vd->vdev_top); 280 281 mutex_enter(&mg->mg_lock); 282 was_allocatable = mg->mg_allocatable; 283 284 mg->mg_free_capacity = ((vs->vs_space - vs->vs_alloc) * 100) / 285 (vs->vs_space + 1); 286 287 mg->mg_allocatable = (mg->mg_free_capacity > zfs_mg_noalloc_threshold); 288 289 /* 290 * The mc_alloc_groups maintains a count of the number of 291 * groups in this metaslab class that are still above the 292 * zfs_mg_noalloc_threshold. This is used by the allocating 293 * threads to determine if they should avoid allocations to 294 * a given group. The allocator will avoid allocations to a group 295 * if that group has reached or is below the zfs_mg_noalloc_threshold 296 * and there are still other groups that are above the threshold. 297 * When a group transitions from allocatable to non-allocatable or 298 * vice versa we update the metaslab class to reflect that change. 299 * When the mc_alloc_groups value drops to 0 that means that all 300 * groups have reached the zfs_mg_noalloc_threshold making all groups 301 * eligible for allocations. This effectively means that all devices 302 * are balanced again. 303 */ 304 if (was_allocatable && !mg->mg_allocatable) 305 mc->mc_alloc_groups--; 306 else if (!was_allocatable && mg->mg_allocatable) 307 mc->mc_alloc_groups++; 308 mutex_exit(&mg->mg_lock); 309 } 310 311 metaslab_group_t * 312 metaslab_group_create(metaslab_class_t *mc, vdev_t *vd) 313 { 314 metaslab_group_t *mg; 315 316 mg = kmem_zalloc(sizeof (metaslab_group_t), KM_SLEEP); 317 mutex_init(&mg->mg_lock, NULL, MUTEX_DEFAULT, NULL); 318 avl_create(&mg->mg_metaslab_tree, metaslab_compare, 319 sizeof (metaslab_t), offsetof(struct metaslab, ms_group_node)); 320 mg->mg_vd = vd; 321 mg->mg_class = mc; 322 mg->mg_activation_count = 0; 323 324 mg->mg_taskq = taskq_create("metaslab_group_taskq", metaslab_load_pct, 325 minclsyspri, 10, INT_MAX, TASKQ_THREADS_CPU_PCT); 326 327 return (mg); 328 } 329 330 void 331 metaslab_group_destroy(metaslab_group_t *mg) 332 { 333 ASSERT(mg->mg_prev == NULL); 334 ASSERT(mg->mg_next == NULL); 335 /* 336 * We may have gone below zero with the activation count 337 * either because we never activated in the first place or 338 * because we're done, and possibly removing the vdev. 339 */ 340 ASSERT(mg->mg_activation_count <= 0); 341 342 taskq_destroy(mg->mg_taskq); 343 avl_destroy(&mg->mg_metaslab_tree); 344 mutex_destroy(&mg->mg_lock); 345 kmem_free(mg, sizeof (metaslab_group_t)); 346 } 347 348 void 349 metaslab_group_activate(metaslab_group_t *mg) 350 { 351 metaslab_class_t *mc = mg->mg_class; 352 metaslab_group_t *mgprev, *mgnext; 353 354 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER)); 355 356 ASSERT(mc->mc_rotor != mg); 357 ASSERT(mg->mg_prev == NULL); 358 ASSERT(mg->mg_next == NULL); 359 ASSERT(mg->mg_activation_count <= 0); 360 361 if (++mg->mg_activation_count <= 0) 362 return; 363 364 mg->mg_aliquot = metaslab_aliquot * MAX(1, mg->mg_vd->vdev_children); 365 metaslab_group_alloc_update(mg); 366 367 if ((mgprev = mc->mc_rotor) == NULL) { 368 mg->mg_prev = mg; 369 mg->mg_next = mg; 370 } else { 371 mgnext = mgprev->mg_next; 372 mg->mg_prev = mgprev; 373 mg->mg_next = mgnext; 374 mgprev->mg_next = mg; 375 mgnext->mg_prev = mg; 376 } 377 mc->mc_rotor = mg; 378 } 379 380 void 381 metaslab_group_passivate(metaslab_group_t *mg) 382 { 383 metaslab_class_t *mc = mg->mg_class; 384 metaslab_group_t *mgprev, *mgnext; 385 386 ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER)); 387 388 if (--mg->mg_activation_count != 0) { 389 ASSERT(mc->mc_rotor != mg); 390 ASSERT(mg->mg_prev == NULL); 391 ASSERT(mg->mg_next == NULL); 392 ASSERT(mg->mg_activation_count < 0); 393 return; 394 } 395 396 taskq_wait(mg->mg_taskq); 397 398 mgprev = mg->mg_prev; 399 mgnext = mg->mg_next; 400 401 if (mg == mgnext) { 402 mc->mc_rotor = NULL; 403 } else { 404 mc->mc_rotor = mgnext; 405 mgprev->mg_next = mgnext; 406 mgnext->mg_prev = mgprev; 407 } 408 409 mg->mg_prev = NULL; 410 mg->mg_next = NULL; 411 } 412 413 static void 414 metaslab_group_add(metaslab_group_t *mg, metaslab_t *msp) 415 { 416 mutex_enter(&mg->mg_lock); 417 ASSERT(msp->ms_group == NULL); 418 msp->ms_group = mg; 419 msp->ms_weight = 0; 420 avl_add(&mg->mg_metaslab_tree, msp); 421 mutex_exit(&mg->mg_lock); 422 } 423 424 static void 425 metaslab_group_remove(metaslab_group_t *mg, metaslab_t *msp) 426 { 427 mutex_enter(&mg->mg_lock); 428 ASSERT(msp->ms_group == mg); 429 avl_remove(&mg->mg_metaslab_tree, msp); 430 msp->ms_group = NULL; 431 mutex_exit(&mg->mg_lock); 432 } 433 434 static void 435 metaslab_group_sort(metaslab_group_t *mg, metaslab_t *msp, uint64_t weight) 436 { 437 /* 438 * Although in principle the weight can be any value, in 439 * practice we do not use values in the range [1, 510]. 440 */ 441 ASSERT(weight >= SPA_MINBLOCKSIZE-1 || weight == 0); 442 ASSERT(MUTEX_HELD(&msp->ms_lock)); 443 444 mutex_enter(&mg->mg_lock); 445 ASSERT(msp->ms_group == mg); 446 avl_remove(&mg->mg_metaslab_tree, msp); 447 msp->ms_weight = weight; 448 avl_add(&mg->mg_metaslab_tree, msp); 449 mutex_exit(&mg->mg_lock); 450 } 451 452 /* 453 * Determine if a given metaslab group should skip allocations. A metaslab 454 * group should avoid allocations if its used capacity has crossed the 455 * zfs_mg_noalloc_threshold and there is at least one metaslab group 456 * that can still handle allocations. 457 */ 458 static boolean_t 459 metaslab_group_allocatable(metaslab_group_t *mg) 460 { 461 vdev_t *vd = mg->mg_vd; 462 spa_t *spa = vd->vdev_spa; 463 metaslab_class_t *mc = mg->mg_class; 464 465 /* 466 * A metaslab group is considered allocatable if its free capacity 467 * is greater than the set value of zfs_mg_noalloc_threshold, it's 468 * associated with a slog, or there are no other metaslab groups 469 * with free capacity greater than zfs_mg_noalloc_threshold. 470 */ 471 return (mg->mg_free_capacity > zfs_mg_noalloc_threshold || 472 mc != spa_normal_class(spa) || mc->mc_alloc_groups == 0); 473 } 474 475 /* 476 * ========================================================================== 477 * Range tree callbacks 478 * ========================================================================== 479 */ 480 481 /* 482 * Comparison function for the private size-ordered tree. Tree is sorted 483 * by size, larger sizes at the end of the tree. 484 */ 485 static int 486 metaslab_rangesize_compare(const void *x1, const void *x2) 487 { 488 const range_seg_t *r1 = x1; 489 const range_seg_t *r2 = x2; 490 uint64_t rs_size1 = r1->rs_end - r1->rs_start; 491 uint64_t rs_size2 = r2->rs_end - r2->rs_start; 492 493 if (rs_size1 < rs_size2) 494 return (-1); 495 if (rs_size1 > rs_size2) 496 return (1); 497 498 if (r1->rs_start < r2->rs_start) 499 return (-1); 500 501 if (r1->rs_start > r2->rs_start) 502 return (1); 503 504 return (0); 505 } 506 507 /* 508 * Create any block allocator specific components. The current allocators 509 * rely on using both a size-ordered range_tree_t and an array of uint64_t's. 510 */ 511 static void 512 metaslab_rt_create(range_tree_t *rt, void *arg) 513 { 514 metaslab_t *msp = arg; 515 516 ASSERT3P(rt->rt_arg, ==, msp); 517 ASSERT(msp->ms_tree == NULL); 518 519 avl_create(&msp->ms_size_tree, metaslab_rangesize_compare, 520 sizeof (range_seg_t), offsetof(range_seg_t, rs_pp_node)); 521 } 522 523 /* 524 * Destroy the block allocator specific components. 525 */ 526 static void 527 metaslab_rt_destroy(range_tree_t *rt, void *arg) 528 { 529 metaslab_t *msp = arg; 530 531 ASSERT3P(rt->rt_arg, ==, msp); 532 ASSERT3P(msp->ms_tree, ==, rt); 533 ASSERT0(avl_numnodes(&msp->ms_size_tree)); 534 535 avl_destroy(&msp->ms_size_tree); 536 } 537 538 static void 539 metaslab_rt_add(range_tree_t *rt, range_seg_t *rs, void *arg) 540 { 541 metaslab_t *msp = arg; 542 543 ASSERT3P(rt->rt_arg, ==, msp); 544 ASSERT3P(msp->ms_tree, ==, rt); 545 VERIFY(!msp->ms_condensing); 546 avl_add(&msp->ms_size_tree, rs); 547 } 548 549 static void 550 metaslab_rt_remove(range_tree_t *rt, range_seg_t *rs, void *arg) 551 { 552 metaslab_t *msp = arg; 553 554 ASSERT3P(rt->rt_arg, ==, msp); 555 ASSERT3P(msp->ms_tree, ==, rt); 556 VERIFY(!msp->ms_condensing); 557 avl_remove(&msp->ms_size_tree, rs); 558 } 559 560 static void 561 metaslab_rt_vacate(range_tree_t *rt, void *arg) 562 { 563 metaslab_t *msp = arg; 564 565 ASSERT3P(rt->rt_arg, ==, msp); 566 ASSERT3P(msp->ms_tree, ==, rt); 567 568 /* 569 * Normally one would walk the tree freeing nodes along the way. 570 * Since the nodes are shared with the range trees we can avoid 571 * walking all nodes and just reinitialize the avl tree. The nodes 572 * will be freed by the range tree, so we don't want to free them here. 573 */ 574 avl_create(&msp->ms_size_tree, metaslab_rangesize_compare, 575 sizeof (range_seg_t), offsetof(range_seg_t, rs_pp_node)); 576 } 577 578 static range_tree_ops_t metaslab_rt_ops = { 579 metaslab_rt_create, 580 metaslab_rt_destroy, 581 metaslab_rt_add, 582 metaslab_rt_remove, 583 metaslab_rt_vacate 584 }; 585 586 /* 587 * ========================================================================== 588 * Metaslab block operations 589 * ========================================================================== 590 */ 591 592 /* 593 * Return the maximum contiguous segment within the metaslab. 594 */ 595 uint64_t 596 metaslab_block_maxsize(metaslab_t *msp) 597 { 598 avl_tree_t *t = &msp->ms_size_tree; 599 range_seg_t *rs; 600 601 if (t == NULL || (rs = avl_last(t)) == NULL) 602 return (0ULL); 603 604 return (rs->rs_end - rs->rs_start); 605 } 606 607 uint64_t 608 metaslab_block_alloc(metaslab_t *msp, uint64_t size) 609 { 610 uint64_t start; 611 range_tree_t *rt = msp->ms_tree; 612 613 VERIFY(!msp->ms_condensing); 614 615 start = msp->ms_ops->msop_alloc(msp, size); 616 if (start != -1ULL) { 617 vdev_t *vd = msp->ms_group->mg_vd; 618 619 VERIFY0(P2PHASE(start, 1ULL << vd->vdev_ashift)); 620 VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift)); 621 VERIFY3U(range_tree_space(rt) - size, <=, msp->ms_size); 622 range_tree_remove(rt, start, size); 623 } 624 return (start); 625 } 626 627 /* 628 * ========================================================================== 629 * Common allocator routines 630 * ========================================================================== 631 */ 632 633 /* 634 * This is a helper function that can be used by the allocator to find 635 * a suitable block to allocate. This will search the specified AVL 636 * tree looking for a block that matches the specified criteria. 637 */ 638 static uint64_t 639 metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size, 640 uint64_t align) 641 { 642 range_seg_t *rs, rsearch; 643 avl_index_t where; 644 645 rsearch.rs_start = *cursor; 646 rsearch.rs_end = *cursor + size; 647 648 rs = avl_find(t, &rsearch, &where); 649 if (rs == NULL) 650 rs = avl_nearest(t, where, AVL_AFTER); 651 652 while (rs != NULL) { 653 uint64_t offset = P2ROUNDUP(rs->rs_start, align); 654 655 if (offset + size <= rs->rs_end) { 656 *cursor = offset + size; 657 return (offset); 658 } 659 rs = AVL_NEXT(t, rs); 660 } 661 662 /* 663 * If we know we've searched the whole map (*cursor == 0), give up. 664 * Otherwise, reset the cursor to the beginning and try again. 665 */ 666 if (*cursor == 0) 667 return (-1ULL); 668 669 *cursor = 0; 670 return (metaslab_block_picker(t, cursor, size, align)); 671 } 672 673 /* 674 * ========================================================================== 675 * The first-fit block allocator 676 * ========================================================================== 677 */ 678 static uint64_t 679 metaslab_ff_alloc(metaslab_t *msp, uint64_t size) 680 { 681 /* 682 * Find the largest power of 2 block size that evenly divides the 683 * requested size. This is used to try to allocate blocks with similar 684 * alignment from the same area of the metaslab (i.e. same cursor 685 * bucket) but it does not guarantee that other allocations sizes 686 * may exist in the same region. 687 */ 688 uint64_t align = size & -size; 689 uint64_t *cursor = &msp->ms_lbas[highbit64(align) - 1]; 690 avl_tree_t *t = &msp->ms_tree->rt_root; 691 692 return (metaslab_block_picker(t, cursor, size, align)); 693 } 694 695 /* ARGSUSED */ 696 static boolean_t 697 metaslab_ff_fragmented(metaslab_t *msp) 698 { 699 return (B_TRUE); 700 } 701 702 static metaslab_ops_t metaslab_ff_ops = { 703 metaslab_ff_alloc, 704 metaslab_ff_fragmented 705 }; 706 707 /* 708 * ========================================================================== 709 * Dynamic block allocator - 710 * Uses the first fit allocation scheme until space get low and then 711 * adjusts to a best fit allocation method. Uses metaslab_df_alloc_threshold 712 * and metaslab_df_free_pct to determine when to switch the allocation scheme. 713 * ========================================================================== 714 */ 715 static uint64_t 716 metaslab_df_alloc(metaslab_t *msp, uint64_t size) 717 { 718 /* 719 * Find the largest power of 2 block size that evenly divides the 720 * requested size. This is used to try to allocate blocks with similar 721 * alignment from the same area of the metaslab (i.e. same cursor 722 * bucket) but it does not guarantee that other allocations sizes 723 * may exist in the same region. 724 */ 725 uint64_t align = size & -size; 726 uint64_t *cursor = &msp->ms_lbas[highbit64(align) - 1]; 727 range_tree_t *rt = msp->ms_tree; 728 avl_tree_t *t = &rt->rt_root; 729 uint64_t max_size = metaslab_block_maxsize(msp); 730 int free_pct = range_tree_space(rt) * 100 / msp->ms_size; 731 732 ASSERT(MUTEX_HELD(&msp->ms_lock)); 733 ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&msp->ms_size_tree)); 734 735 if (max_size < size) 736 return (-1ULL); 737 738 /* 739 * If we're running low on space switch to using the size 740 * sorted AVL tree (best-fit). 741 */ 742 if (max_size < metaslab_df_alloc_threshold || 743 free_pct < metaslab_df_free_pct) { 744 t = &msp->ms_size_tree; 745 *cursor = 0; 746 } 747 748 return (metaslab_block_picker(t, cursor, size, 1ULL)); 749 } 750 751 static boolean_t 752 metaslab_df_fragmented(metaslab_t *msp) 753 { 754 range_tree_t *rt = msp->ms_tree; 755 uint64_t max_size = metaslab_block_maxsize(msp); 756 int free_pct = range_tree_space(rt) * 100 / msp->ms_size; 757 758 if (max_size >= metaslab_df_alloc_threshold && 759 free_pct >= metaslab_df_free_pct) 760 return (B_FALSE); 761 762 return (B_TRUE); 763 } 764 765 static metaslab_ops_t metaslab_df_ops = { 766 metaslab_df_alloc, 767 metaslab_df_fragmented 768 }; 769 770 /* 771 * ========================================================================== 772 * Cursor fit block allocator - 773 * Select the largest region in the metaslab, set the cursor to the beginning 774 * of the range and the cursor_end to the end of the range. As allocations 775 * are made advance the cursor. Continue allocating from the cursor until 776 * the range is exhausted and then find a new range. 777 * ========================================================================== 778 */ 779 static uint64_t 780 metaslab_cf_alloc(metaslab_t *msp, uint64_t size) 781 { 782 range_tree_t *rt = msp->ms_tree; 783 avl_tree_t *t = &msp->ms_size_tree; 784 uint64_t *cursor = &msp->ms_lbas[0]; 785 uint64_t *cursor_end = &msp->ms_lbas[1]; 786 uint64_t offset = 0; 787 788 ASSERT(MUTEX_HELD(&msp->ms_lock)); 789 ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&rt->rt_root)); 790 791 ASSERT3U(*cursor_end, >=, *cursor); 792 793 if ((*cursor + size) > *cursor_end) { 794 range_seg_t *rs; 795 796 rs = avl_last(&msp->ms_size_tree); 797 if (rs == NULL || (rs->rs_end - rs->rs_start) < size) 798 return (-1ULL); 799 800 *cursor = rs->rs_start; 801 *cursor_end = rs->rs_end; 802 } 803 804 offset = *cursor; 805 *cursor += size; 806 807 return (offset); 808 } 809 810 static boolean_t 811 metaslab_cf_fragmented(metaslab_t *msp) 812 { 813 return (metaslab_block_maxsize(msp) < metaslab_min_alloc_size); 814 } 815 816 static metaslab_ops_t metaslab_cf_ops = { 817 metaslab_cf_alloc, 818 metaslab_cf_fragmented 819 }; 820 821 /* 822 * ========================================================================== 823 * New dynamic fit allocator - 824 * Select a region that is large enough to allocate 2^metaslab_ndf_clump_shift 825 * contiguous blocks. If no region is found then just use the largest segment 826 * that remains. 827 * ========================================================================== 828 */ 829 830 /* 831 * Determines desired number of contiguous blocks (2^metaslab_ndf_clump_shift) 832 * to request from the allocator. 833 */ 834 uint64_t metaslab_ndf_clump_shift = 4; 835 836 static uint64_t 837 metaslab_ndf_alloc(metaslab_t *msp, uint64_t size) 838 { 839 avl_tree_t *t = &msp->ms_tree->rt_root; 840 avl_index_t where; 841 range_seg_t *rs, rsearch; 842 uint64_t hbit = highbit64(size); 843 uint64_t *cursor = &msp->ms_lbas[hbit - 1]; 844 uint64_t max_size = metaslab_block_maxsize(msp); 845 846 ASSERT(MUTEX_HELD(&msp->ms_lock)); 847 ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&msp->ms_size_tree)); 848 849 if (max_size < size) 850 return (-1ULL); 851 852 rsearch.rs_start = *cursor; 853 rsearch.rs_end = *cursor + size; 854 855 rs = avl_find(t, &rsearch, &where); 856 if (rs == NULL || (rs->rs_end - rs->rs_start) < size) { 857 t = &msp->ms_size_tree; 858 859 rsearch.rs_start = 0; 860 rsearch.rs_end = MIN(max_size, 861 1ULL << (hbit + metaslab_ndf_clump_shift)); 862 rs = avl_find(t, &rsearch, &where); 863 if (rs == NULL) 864 rs = avl_nearest(t, where, AVL_AFTER); 865 ASSERT(rs != NULL); 866 } 867 868 if ((rs->rs_end - rs->rs_start) >= size) { 869 *cursor = rs->rs_start + size; 870 return (rs->rs_start); 871 } 872 return (-1ULL); 873 } 874 875 static boolean_t 876 metaslab_ndf_fragmented(metaslab_t *msp) 877 { 878 return (metaslab_block_maxsize(msp) <= 879 (metaslab_min_alloc_size << metaslab_ndf_clump_shift)); 880 } 881 882 static metaslab_ops_t metaslab_ndf_ops = { 883 metaslab_ndf_alloc, 884 metaslab_ndf_fragmented 885 }; 886 887 metaslab_ops_t *zfs_metaslab_ops = &metaslab_df_ops; 888 889 /* 890 * ========================================================================== 891 * Metaslabs 892 * ========================================================================== 893 */ 894 895 /* 896 * Wait for any in-progress metaslab loads to complete. 897 */ 898 void 899 metaslab_load_wait(metaslab_t *msp) 900 { 901 ASSERT(MUTEX_HELD(&msp->ms_lock)); 902 903 while (msp->ms_loading) { 904 ASSERT(!msp->ms_loaded); 905 cv_wait(&msp->ms_load_cv, &msp->ms_lock); 906 } 907 } 908 909 int 910 metaslab_load(metaslab_t *msp) 911 { 912 int error = 0; 913 914 ASSERT(MUTEX_HELD(&msp->ms_lock)); 915 ASSERT(!msp->ms_loaded); 916 ASSERT(!msp->ms_loading); 917 918 msp->ms_loading = B_TRUE; 919 920 /* 921 * If the space map has not been allocated yet, then treat 922 * all the space in the metaslab as free and add it to the 923 * ms_tree. 924 */ 925 if (msp->ms_sm != NULL) 926 error = space_map_load(msp->ms_sm, msp->ms_tree, SM_FREE); 927 else 928 range_tree_add(msp->ms_tree, msp->ms_start, msp->ms_size); 929 930 msp->ms_loaded = (error == 0); 931 msp->ms_loading = B_FALSE; 932 933 if (msp->ms_loaded) { 934 for (int t = 0; t < TXG_DEFER_SIZE; t++) { 935 range_tree_walk(msp->ms_defertree[t], 936 range_tree_remove, msp->ms_tree); 937 } 938 } 939 cv_broadcast(&msp->ms_load_cv); 940 return (error); 941 } 942 943 void 944 metaslab_unload(metaslab_t *msp) 945 { 946 ASSERT(MUTEX_HELD(&msp->ms_lock)); 947 range_tree_vacate(msp->ms_tree, NULL, NULL); 948 msp->ms_loaded = B_FALSE; 949 msp->ms_weight &= ~METASLAB_ACTIVE_MASK; 950 } 951 952 metaslab_t * 953 metaslab_init(metaslab_group_t *mg, uint64_t id, uint64_t object, uint64_t txg) 954 { 955 vdev_t *vd = mg->mg_vd; 956 objset_t *mos = vd->vdev_spa->spa_meta_objset; 957 metaslab_t *msp; 958 959 msp = kmem_zalloc(sizeof (metaslab_t), KM_SLEEP); 960 mutex_init(&msp->ms_lock, NULL, MUTEX_DEFAULT, NULL); 961 cv_init(&msp->ms_load_cv, NULL, CV_DEFAULT, NULL); 962 msp->ms_id = id; 963 msp->ms_start = id << vd->vdev_ms_shift; 964 msp->ms_size = 1ULL << vd->vdev_ms_shift; 965 966 /* 967 * We only open space map objects that already exist. All others 968 * will be opened when we finally allocate an object for it. 969 */ 970 if (object != 0) { 971 VERIFY0(space_map_open(&msp->ms_sm, mos, object, msp->ms_start, 972 msp->ms_size, vd->vdev_ashift, &msp->ms_lock)); 973 ASSERT(msp->ms_sm != NULL); 974 } 975 976 /* 977 * We create the main range tree here, but we don't create the 978 * alloctree and freetree until metaslab_sync_done(). This serves 979 * two purposes: it allows metaslab_sync_done() to detect the 980 * addition of new space; and for debugging, it ensures that we'd 981 * data fault on any attempt to use this metaslab before it's ready. 982 */ 983 msp->ms_tree = range_tree_create(&metaslab_rt_ops, msp, &msp->ms_lock); 984 metaslab_group_add(mg, msp); 985 986 msp->ms_ops = mg->mg_class->mc_ops; 987 988 /* 989 * If we're opening an existing pool (txg == 0) or creating 990 * a new one (txg == TXG_INITIAL), all space is available now. 991 * If we're adding space to an existing pool, the new space 992 * does not become available until after this txg has synced. 993 */ 994 if (txg <= TXG_INITIAL) 995 metaslab_sync_done(msp, 0); 996 997 /* 998 * If metaslab_debug_load is set and we're initializing a metaslab 999 * that has an allocated space_map object then load the its space 1000 * map so that can verify frees. 1001 */ 1002 if (metaslab_debug_load && msp->ms_sm != NULL) { 1003 mutex_enter(&msp->ms_lock); 1004 VERIFY0(metaslab_load(msp)); 1005 mutex_exit(&msp->ms_lock); 1006 } 1007 1008 if (txg != 0) { 1009 vdev_dirty(vd, 0, NULL, txg); 1010 vdev_dirty(vd, VDD_METASLAB, msp, txg); 1011 } 1012 1013 return (msp); 1014 } 1015 1016 void 1017 metaslab_fini(metaslab_t *msp) 1018 { 1019 metaslab_group_t *mg = msp->ms_group; 1020 1021 metaslab_group_remove(mg, msp); 1022 1023 mutex_enter(&msp->ms_lock); 1024 1025 VERIFY(msp->ms_group == NULL); 1026 vdev_space_update(mg->mg_vd, -space_map_allocated(msp->ms_sm), 1027 0, -msp->ms_size); 1028 space_map_close(msp->ms_sm); 1029 1030 metaslab_unload(msp); 1031 range_tree_destroy(msp->ms_tree); 1032 1033 for (int t = 0; t < TXG_SIZE; t++) { 1034 range_tree_destroy(msp->ms_alloctree[t]); 1035 range_tree_destroy(msp->ms_freetree[t]); 1036 } 1037 1038 for (int t = 0; t < TXG_DEFER_SIZE; t++) { 1039 range_tree_destroy(msp->ms_defertree[t]); 1040 } 1041 1042 ASSERT0(msp->ms_deferspace); 1043 1044 mutex_exit(&msp->ms_lock); 1045 cv_destroy(&msp->ms_load_cv); 1046 mutex_destroy(&msp->ms_lock); 1047 1048 kmem_free(msp, sizeof (metaslab_t)); 1049 } 1050 1051 /* 1052 * Apply a weighting factor based on the histogram information for this 1053 * metaslab. The current weighting factor is somewhat arbitrary and requires 1054 * additional investigation. The implementation provides a measure of 1055 * "weighted" free space and gives a higher weighting for larger contiguous 1056 * regions. The weighting factor is determined by counting the number of 1057 * sm_shift sectors that exist in each region represented by the histogram. 1058 * That value is then multiplied by the power of 2 exponent and the sm_shift 1059 * value. 1060 * 1061 * For example, assume the 2^21 histogram bucket has 4 2MB regions and the 1062 * metaslab has an sm_shift value of 9 (512B): 1063 * 1064 * 1) calculate the number of sm_shift sectors in the region: 1065 * 2^21 / 2^9 = 2^12 = 4096 * 4 (number of regions) = 16384 1066 * 2) multiply by the power of 2 exponent and the sm_shift value: 1067 * 16384 * 21 * 9 = 3096576 1068 * This value will be added to the weighting of the metaslab. 1069 */ 1070 static uint64_t 1071 metaslab_weight_factor(metaslab_t *msp) 1072 { 1073 uint64_t factor = 0; 1074 uint64_t sectors; 1075 int i; 1076 1077 /* 1078 * A null space map means that the entire metaslab is free, 1079 * calculate a weight factor that spans the entire size of the 1080 * metaslab. 1081 */ 1082 if (msp->ms_sm == NULL) { 1083 vdev_t *vd = msp->ms_group->mg_vd; 1084 1085 i = highbit64(msp->ms_size) - 1; 1086 sectors = msp->ms_size >> vd->vdev_ashift; 1087 return (sectors * i * vd->vdev_ashift); 1088 } 1089 1090 if (msp->ms_sm->sm_dbuf->db_size != sizeof (space_map_phys_t)) 1091 return (0); 1092 1093 for (i = 0; i < SPACE_MAP_HISTOGRAM_SIZE(msp->ms_sm); i++) { 1094 if (msp->ms_sm->sm_phys->smp_histogram[i] == 0) 1095 continue; 1096 1097 /* 1098 * Determine the number of sm_shift sectors in the region 1099 * indicated by the histogram. For example, given an 1100 * sm_shift value of 9 (512 bytes) and i = 4 then we know 1101 * that we're looking at an 8K region in the histogram 1102 * (i.e. 9 + 4 = 13, 2^13 = 8192). To figure out the 1103 * number of sm_shift sectors (512 bytes in this example), 1104 * we would take 8192 / 512 = 16. Since the histogram 1105 * is offset by sm_shift we can simply use the value of 1106 * of i to calculate this (i.e. 2^i = 16 where i = 4). 1107 */ 1108 sectors = msp->ms_sm->sm_phys->smp_histogram[i] << i; 1109 factor += (i + msp->ms_sm->sm_shift) * sectors; 1110 } 1111 return (factor * msp->ms_sm->sm_shift); 1112 } 1113 1114 static uint64_t 1115 metaslab_weight(metaslab_t *msp) 1116 { 1117 metaslab_group_t *mg = msp->ms_group; 1118 vdev_t *vd = mg->mg_vd; 1119 uint64_t weight, space; 1120 1121 ASSERT(MUTEX_HELD(&msp->ms_lock)); 1122 1123 /* 1124 * This vdev is in the process of being removed so there is nothing 1125 * for us to do here. 1126 */ 1127 if (vd->vdev_removing) { 1128 ASSERT0(space_map_allocated(msp->ms_sm)); 1129 ASSERT0(vd->vdev_ms_shift); 1130 return (0); 1131 } 1132 1133 /* 1134 * The baseline weight is the metaslab's free space. 1135 */ 1136 space = msp->ms_size - space_map_allocated(msp->ms_sm); 1137 weight = space; 1138 1139 /* 1140 * Modern disks have uniform bit density and constant angular velocity. 1141 * Therefore, the outer recording zones are faster (higher bandwidth) 1142 * than the inner zones by the ratio of outer to inner track diameter, 1143 * which is typically around 2:1. We account for this by assigning 1144 * higher weight to lower metaslabs (multiplier ranging from 2x to 1x). 1145 * In effect, this means that we'll select the metaslab with the most 1146 * free bandwidth rather than simply the one with the most free space. 1147 */ 1148 weight = 2 * weight - (msp->ms_id * weight) / vd->vdev_ms_count; 1149 ASSERT(weight >= space && weight <= 2 * space); 1150 1151 msp->ms_factor = metaslab_weight_factor(msp); 1152 if (metaslab_weight_factor_enable) 1153 weight += msp->ms_factor; 1154 1155 if (msp->ms_loaded && !msp->ms_ops->msop_fragmented(msp)) { 1156 /* 1157 * If this metaslab is one we're actively using, adjust its 1158 * weight to make it preferable to any inactive metaslab so 1159 * we'll polish it off. 1160 */ 1161 weight |= (msp->ms_weight & METASLAB_ACTIVE_MASK); 1162 } 1163 1164 return (weight); 1165 } 1166 1167 static int 1168 metaslab_activate(metaslab_t *msp, uint64_t activation_weight) 1169 { 1170 ASSERT(MUTEX_HELD(&msp->ms_lock)); 1171 1172 if ((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) { 1173 metaslab_load_wait(msp); 1174 if (!msp->ms_loaded) { 1175 int error = metaslab_load(msp); 1176 if (error) { 1177 metaslab_group_sort(msp->ms_group, msp, 0); 1178 return (error); 1179 } 1180 } 1181 1182 metaslab_group_sort(msp->ms_group, msp, 1183 msp->ms_weight | activation_weight); 1184 } 1185 ASSERT(msp->ms_loaded); 1186 ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK); 1187 1188 return (0); 1189 } 1190 1191 static void 1192 metaslab_passivate(metaslab_t *msp, uint64_t size) 1193 { 1194 /* 1195 * If size < SPA_MINBLOCKSIZE, then we will not allocate from 1196 * this metaslab again. In that case, it had better be empty, 1197 * or we would be leaving space on the table. 1198 */ 1199 ASSERT(size >= SPA_MINBLOCKSIZE || range_tree_space(msp->ms_tree) == 0); 1200 metaslab_group_sort(msp->ms_group, msp, MIN(msp->ms_weight, size)); 1201 ASSERT((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0); 1202 } 1203 1204 static void 1205 metaslab_preload(void *arg) 1206 { 1207 metaslab_t *msp = arg; 1208 spa_t *spa = msp->ms_group->mg_vd->vdev_spa; 1209 1210 mutex_enter(&msp->ms_lock); 1211 metaslab_load_wait(msp); 1212 if (!msp->ms_loaded) 1213 (void) metaslab_load(msp); 1214 1215 /* 1216 * Set the ms_access_txg value so that we don't unload it right away. 1217 */ 1218 msp->ms_access_txg = spa_syncing_txg(spa) + metaslab_unload_delay + 1; 1219 mutex_exit(&msp->ms_lock); 1220 } 1221 1222 static void 1223 metaslab_group_preload(metaslab_group_t *mg) 1224 { 1225 spa_t *spa = mg->mg_vd->vdev_spa; 1226 metaslab_t *msp; 1227 avl_tree_t *t = &mg->mg_metaslab_tree; 1228 int m = 0; 1229 1230 if (spa_shutting_down(spa) || !metaslab_preload_enabled) { 1231 taskq_wait(mg->mg_taskq); 1232 return; 1233 } 1234 mutex_enter(&mg->mg_lock); 1235 1236 /* 1237 * Prefetch the next potential metaslabs 1238 */ 1239 for (msp = avl_first(t); msp != NULL; msp = AVL_NEXT(t, msp)) { 1240 1241 /* If we have reached our preload limit then we're done */ 1242 if (++m > metaslab_preload_limit) 1243 break; 1244 1245 VERIFY(taskq_dispatch(mg->mg_taskq, metaslab_preload, 1246 msp, TQ_SLEEP) != NULL); 1247 } 1248 mutex_exit(&mg->mg_lock); 1249 } 1250 1251 /* 1252 * Determine if the space map's on-disk footprint is past our tolerance 1253 * for inefficiency. We would like to use the following criteria to make 1254 * our decision: 1255 * 1256 * 1. The size of the space map object should not dramatically increase as a 1257 * result of writing out the free space range tree. 1258 * 1259 * 2. The minimal on-disk space map representation is zfs_condense_pct/100 1260 * times the size than the free space range tree representation 1261 * (i.e. zfs_condense_pct = 110 and in-core = 1MB, minimal = 1.1.MB). 1262 * 1263 * Checking the first condition is tricky since we don't want to walk 1264 * the entire AVL tree calculating the estimated on-disk size. Instead we 1265 * use the size-ordered range tree in the metaslab and calculate the 1266 * size required to write out the largest segment in our free tree. If the 1267 * size required to represent that segment on disk is larger than the space 1268 * map object then we avoid condensing this map. 1269 * 1270 * To determine the second criterion we use a best-case estimate and assume 1271 * each segment can be represented on-disk as a single 64-bit entry. We refer 1272 * to this best-case estimate as the space map's minimal form. 1273 */ 1274 static boolean_t 1275 metaslab_should_condense(metaslab_t *msp) 1276 { 1277 space_map_t *sm = msp->ms_sm; 1278 range_seg_t *rs; 1279 uint64_t size, entries, segsz; 1280 1281 ASSERT(MUTEX_HELD(&msp->ms_lock)); 1282 ASSERT(msp->ms_loaded); 1283 1284 /* 1285 * Use the ms_size_tree range tree, which is ordered by size, to 1286 * obtain the largest segment in the free tree. If the tree is empty 1287 * then we should condense the map. 1288 */ 1289 rs = avl_last(&msp->ms_size_tree); 1290 if (rs == NULL) 1291 return (B_TRUE); 1292 1293 /* 1294 * Calculate the number of 64-bit entries this segment would 1295 * require when written to disk. If this single segment would be 1296 * larger on-disk than the entire current on-disk structure, then 1297 * clearly condensing will increase the on-disk structure size. 1298 */ 1299 size = (rs->rs_end - rs->rs_start) >> sm->sm_shift; 1300 entries = size / (MIN(size, SM_RUN_MAX)); 1301 segsz = entries * sizeof (uint64_t); 1302 1303 return (segsz <= space_map_length(msp->ms_sm) && 1304 space_map_length(msp->ms_sm) >= (zfs_condense_pct * 1305 sizeof (uint64_t) * avl_numnodes(&msp->ms_tree->rt_root)) / 100); 1306 } 1307 1308 /* 1309 * Condense the on-disk space map representation to its minimized form. 1310 * The minimized form consists of a small number of allocations followed by 1311 * the entries of the free range tree. 1312 */ 1313 static void 1314 metaslab_condense(metaslab_t *msp, uint64_t txg, dmu_tx_t *tx) 1315 { 1316 spa_t *spa = msp->ms_group->mg_vd->vdev_spa; 1317 range_tree_t *freetree = msp->ms_freetree[txg & TXG_MASK]; 1318 range_tree_t *condense_tree; 1319 space_map_t *sm = msp->ms_sm; 1320 1321 ASSERT(MUTEX_HELD(&msp->ms_lock)); 1322 ASSERT3U(spa_sync_pass(spa), ==, 1); 1323 ASSERT(msp->ms_loaded); 1324 1325 spa_dbgmsg(spa, "condensing: txg %llu, msp[%llu] %p, " 1326 "smp size %llu, segments %lu", txg, msp->ms_id, msp, 1327 space_map_length(msp->ms_sm), avl_numnodes(&msp->ms_tree->rt_root)); 1328 1329 /* 1330 * Create an range tree that is 100% allocated. We remove segments 1331 * that have been freed in this txg, any deferred frees that exist, 1332 * and any allocation in the future. Removing segments should be 1333 * a relatively inexpensive operation since we expect these trees to 1334 * have a small number of nodes. 1335 */ 1336 condense_tree = range_tree_create(NULL, NULL, &msp->ms_lock); 1337 range_tree_add(condense_tree, msp->ms_start, msp->ms_size); 1338 1339 /* 1340 * Remove what's been freed in this txg from the condense_tree. 1341 * Since we're in sync_pass 1, we know that all the frees from 1342 * this txg are in the freetree. 1343 */ 1344 range_tree_walk(freetree, range_tree_remove, condense_tree); 1345 1346 for (int t = 0; t < TXG_DEFER_SIZE; t++) { 1347 range_tree_walk(msp->ms_defertree[t], 1348 range_tree_remove, condense_tree); 1349 } 1350 1351 for (int t = 1; t < TXG_CONCURRENT_STATES; t++) { 1352 range_tree_walk(msp->ms_alloctree[(txg + t) & TXG_MASK], 1353 range_tree_remove, condense_tree); 1354 } 1355 1356 /* 1357 * We're about to drop the metaslab's lock thus allowing 1358 * other consumers to change it's content. Set the 1359 * metaslab's ms_condensing flag to ensure that 1360 * allocations on this metaslab do not occur while we're 1361 * in the middle of committing it to disk. This is only critical 1362 * for the ms_tree as all other range trees use per txg 1363 * views of their content. 1364 */ 1365 msp->ms_condensing = B_TRUE; 1366 1367 mutex_exit(&msp->ms_lock); 1368 space_map_truncate(sm, tx); 1369 mutex_enter(&msp->ms_lock); 1370 1371 /* 1372 * While we would ideally like to create a space_map representation 1373 * that consists only of allocation records, doing so can be 1374 * prohibitively expensive because the in-core free tree can be 1375 * large, and therefore computationally expensive to subtract 1376 * from the condense_tree. Instead we sync out two trees, a cheap 1377 * allocation only tree followed by the in-core free tree. While not 1378 * optimal, this is typically close to optimal, and much cheaper to 1379 * compute. 1380 */ 1381 space_map_write(sm, condense_tree, SM_ALLOC, tx); 1382 range_tree_vacate(condense_tree, NULL, NULL); 1383 range_tree_destroy(condense_tree); 1384 1385 space_map_write(sm, msp->ms_tree, SM_FREE, tx); 1386 msp->ms_condensing = B_FALSE; 1387 } 1388 1389 /* 1390 * Write a metaslab to disk in the context of the specified transaction group. 1391 */ 1392 void 1393 metaslab_sync(metaslab_t *msp, uint64_t txg) 1394 { 1395 metaslab_group_t *mg = msp->ms_group; 1396 vdev_t *vd = mg->mg_vd; 1397 spa_t *spa = vd->vdev_spa; 1398 objset_t *mos = spa_meta_objset(spa); 1399 range_tree_t *alloctree = msp->ms_alloctree[txg & TXG_MASK]; 1400 range_tree_t **freetree = &msp->ms_freetree[txg & TXG_MASK]; 1401 range_tree_t **freed_tree = 1402 &msp->ms_freetree[TXG_CLEAN(txg) & TXG_MASK]; 1403 dmu_tx_t *tx; 1404 uint64_t object = space_map_object(msp->ms_sm); 1405 1406 ASSERT(!vd->vdev_ishole); 1407 1408 /* 1409 * This metaslab has just been added so there's no work to do now. 1410 */ 1411 if (*freetree == NULL) { 1412 ASSERT3P(alloctree, ==, NULL); 1413 return; 1414 } 1415 1416 ASSERT3P(alloctree, !=, NULL); 1417 ASSERT3P(*freetree, !=, NULL); 1418 ASSERT3P(*freed_tree, !=, NULL); 1419 1420 if (range_tree_space(alloctree) == 0 && 1421 range_tree_space(*freetree) == 0) 1422 return; 1423 1424 /* 1425 * The only state that can actually be changing concurrently with 1426 * metaslab_sync() is the metaslab's ms_tree. No other thread can 1427 * be modifying this txg's alloctree, freetree, freed_tree, or 1428 * space_map_phys_t. Therefore, we only hold ms_lock to satify 1429 * space_map ASSERTs. We drop it whenever we call into the DMU, 1430 * because the DMU can call down to us (e.g. via zio_free()) at 1431 * any time. 1432 */ 1433 1434 tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg); 1435 1436 if (msp->ms_sm == NULL) { 1437 uint64_t new_object; 1438 1439 new_object = space_map_alloc(mos, tx); 1440 VERIFY3U(new_object, !=, 0); 1441 1442 VERIFY0(space_map_open(&msp->ms_sm, mos, new_object, 1443 msp->ms_start, msp->ms_size, vd->vdev_ashift, 1444 &msp->ms_lock)); 1445 ASSERT(msp->ms_sm != NULL); 1446 } 1447 1448 mutex_enter(&msp->ms_lock); 1449 1450 if (msp->ms_loaded && spa_sync_pass(spa) == 1 && 1451 metaslab_should_condense(msp)) { 1452 metaslab_condense(msp, txg, tx); 1453 } else { 1454 space_map_write(msp->ms_sm, alloctree, SM_ALLOC, tx); 1455 space_map_write(msp->ms_sm, *freetree, SM_FREE, tx); 1456 } 1457 1458 range_tree_vacate(alloctree, NULL, NULL); 1459 1460 if (msp->ms_loaded) { 1461 /* 1462 * When the space map is loaded, we have an accruate 1463 * histogram in the range tree. This gives us an opportunity 1464 * to bring the space map's histogram up-to-date so we clear 1465 * it first before updating it. 1466 */ 1467 space_map_histogram_clear(msp->ms_sm); 1468 space_map_histogram_add(msp->ms_sm, msp->ms_tree, tx); 1469 } else { 1470 /* 1471 * Since the space map is not loaded we simply update the 1472 * exisiting histogram with what was freed in this txg. This 1473 * means that the on-disk histogram may not have an accurate 1474 * view of the free space but it's close enough to allow 1475 * us to make allocation decisions. 1476 */ 1477 space_map_histogram_add(msp->ms_sm, *freetree, tx); 1478 } 1479 1480 /* 1481 * For sync pass 1, we avoid traversing this txg's free range tree 1482 * and instead will just swap the pointers for freetree and 1483 * freed_tree. We can safely do this since the freed_tree is 1484 * guaranteed to be empty on the initial pass. 1485 */ 1486 if (spa_sync_pass(spa) == 1) { 1487 range_tree_swap(freetree, freed_tree); 1488 } else { 1489 range_tree_vacate(*freetree, range_tree_add, *freed_tree); 1490 } 1491 1492 ASSERT0(range_tree_space(msp->ms_alloctree[txg & TXG_MASK])); 1493 ASSERT0(range_tree_space(msp->ms_freetree[txg & TXG_MASK])); 1494 1495 mutex_exit(&msp->ms_lock); 1496 1497 if (object != space_map_object(msp->ms_sm)) { 1498 object = space_map_object(msp->ms_sm); 1499 dmu_write(mos, vd->vdev_ms_array, sizeof (uint64_t) * 1500 msp->ms_id, sizeof (uint64_t), &object, tx); 1501 } 1502 dmu_tx_commit(tx); 1503 } 1504 1505 /* 1506 * Called after a transaction group has completely synced to mark 1507 * all of the metaslab's free space as usable. 1508 */ 1509 void 1510 metaslab_sync_done(metaslab_t *msp, uint64_t txg) 1511 { 1512 metaslab_group_t *mg = msp->ms_group; 1513 vdev_t *vd = mg->mg_vd; 1514 range_tree_t **freed_tree; 1515 range_tree_t **defer_tree; 1516 int64_t alloc_delta, defer_delta; 1517 1518 ASSERT(!vd->vdev_ishole); 1519 1520 mutex_enter(&msp->ms_lock); 1521 1522 /* 1523 * If this metaslab is just becoming available, initialize its 1524 * alloctrees, freetrees, and defertree and add its capacity to 1525 * the vdev. 1526 */ 1527 if (msp->ms_freetree[TXG_CLEAN(txg) & TXG_MASK] == NULL) { 1528 for (int t = 0; t < TXG_SIZE; t++) { 1529 ASSERT(msp->ms_alloctree[t] == NULL); 1530 ASSERT(msp->ms_freetree[t] == NULL); 1531 1532 msp->ms_alloctree[t] = range_tree_create(NULL, msp, 1533 &msp->ms_lock); 1534 msp->ms_freetree[t] = range_tree_create(NULL, msp, 1535 &msp->ms_lock); 1536 } 1537 1538 for (int t = 0; t < TXG_DEFER_SIZE; t++) { 1539 ASSERT(msp->ms_defertree[t] == NULL); 1540 1541 msp->ms_defertree[t] = range_tree_create(NULL, msp, 1542 &msp->ms_lock); 1543 } 1544 1545 vdev_space_update(vd, 0, 0, msp->ms_size); 1546 } 1547 1548 freed_tree = &msp->ms_freetree[TXG_CLEAN(txg) & TXG_MASK]; 1549 defer_tree = &msp->ms_defertree[txg % TXG_DEFER_SIZE]; 1550 1551 alloc_delta = space_map_alloc_delta(msp->ms_sm); 1552 defer_delta = range_tree_space(*freed_tree) - 1553 range_tree_space(*defer_tree); 1554 1555 vdev_space_update(vd, alloc_delta + defer_delta, defer_delta, 0); 1556 1557 ASSERT0(range_tree_space(msp->ms_alloctree[txg & TXG_MASK])); 1558 ASSERT0(range_tree_space(msp->ms_freetree[txg & TXG_MASK])); 1559 1560 /* 1561 * If there's a metaslab_load() in progress, wait for it to complete 1562 * so that we have a consistent view of the in-core space map. 1563 */ 1564 metaslab_load_wait(msp); 1565 1566 /* 1567 * Move the frees from the defer_tree back to the free 1568 * range tree (if it's loaded). Swap the freed_tree and the 1569 * defer_tree -- this is safe to do because we've just emptied out 1570 * the defer_tree. 1571 */ 1572 range_tree_vacate(*defer_tree, 1573 msp->ms_loaded ? range_tree_add : NULL, msp->ms_tree); 1574 range_tree_swap(freed_tree, defer_tree); 1575 1576 space_map_update(msp->ms_sm); 1577 1578 msp->ms_deferspace += defer_delta; 1579 ASSERT3S(msp->ms_deferspace, >=, 0); 1580 ASSERT3S(msp->ms_deferspace, <=, msp->ms_size); 1581 if (msp->ms_deferspace != 0) { 1582 /* 1583 * Keep syncing this metaslab until all deferred frees 1584 * are back in circulation. 1585 */ 1586 vdev_dirty(vd, VDD_METASLAB, msp, txg + 1); 1587 } 1588 1589 if (msp->ms_loaded && msp->ms_access_txg < txg) { 1590 for (int t = 1; t < TXG_CONCURRENT_STATES; t++) { 1591 VERIFY0(range_tree_space( 1592 msp->ms_alloctree[(txg + t) & TXG_MASK])); 1593 } 1594 1595 if (!metaslab_debug_unload) 1596 metaslab_unload(msp); 1597 } 1598 1599 metaslab_group_sort(mg, msp, metaslab_weight(msp)); 1600 mutex_exit(&msp->ms_lock); 1601 1602 } 1603 1604 void 1605 metaslab_sync_reassess(metaslab_group_t *mg) 1606 { 1607 metaslab_group_alloc_update(mg); 1608 1609 /* 1610 * Preload the next potential metaslabs 1611 */ 1612 metaslab_group_preload(mg); 1613 } 1614 1615 static uint64_t 1616 metaslab_distance(metaslab_t *msp, dva_t *dva) 1617 { 1618 uint64_t ms_shift = msp->ms_group->mg_vd->vdev_ms_shift; 1619 uint64_t offset = DVA_GET_OFFSET(dva) >> ms_shift; 1620 uint64_t start = msp->ms_id; 1621 1622 if (msp->ms_group->mg_vd->vdev_id != DVA_GET_VDEV(dva)) 1623 return (1ULL << 63); 1624 1625 if (offset < start) 1626 return ((start - offset) << ms_shift); 1627 if (offset > start) 1628 return ((offset - start) << ms_shift); 1629 return (0); 1630 } 1631 1632 static uint64_t 1633 metaslab_group_alloc(metaslab_group_t *mg, uint64_t psize, uint64_t asize, 1634 uint64_t txg, uint64_t min_distance, dva_t *dva, int d) 1635 { 1636 spa_t *spa = mg->mg_vd->vdev_spa; 1637 metaslab_t *msp = NULL; 1638 uint64_t offset = -1ULL; 1639 avl_tree_t *t = &mg->mg_metaslab_tree; 1640 uint64_t activation_weight; 1641 uint64_t target_distance; 1642 int i; 1643 1644 activation_weight = METASLAB_WEIGHT_PRIMARY; 1645 for (i = 0; i < d; i++) { 1646 if (DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) { 1647 activation_weight = METASLAB_WEIGHT_SECONDARY; 1648 break; 1649 } 1650 } 1651 1652 for (;;) { 1653 boolean_t was_active; 1654 1655 mutex_enter(&mg->mg_lock); 1656 for (msp = avl_first(t); msp; msp = AVL_NEXT(t, msp)) { 1657 if (msp->ms_weight < asize) { 1658 spa_dbgmsg(spa, "%s: failed to meet weight " 1659 "requirement: vdev %llu, txg %llu, mg %p, " 1660 "msp %p, psize %llu, asize %llu, " 1661 "weight %llu", spa_name(spa), 1662 mg->mg_vd->vdev_id, txg, 1663 mg, msp, psize, asize, msp->ms_weight); 1664 mutex_exit(&mg->mg_lock); 1665 return (-1ULL); 1666 } 1667 1668 /* 1669 * If the selected metaslab is condensing, skip it. 1670 */ 1671 if (msp->ms_condensing) 1672 continue; 1673 1674 was_active = msp->ms_weight & METASLAB_ACTIVE_MASK; 1675 if (activation_weight == METASLAB_WEIGHT_PRIMARY) 1676 break; 1677 1678 target_distance = min_distance + 1679 (space_map_allocated(msp->ms_sm) != 0 ? 0 : 1680 min_distance >> 1); 1681 1682 for (i = 0; i < d; i++) 1683 if (metaslab_distance(msp, &dva[i]) < 1684 target_distance) 1685 break; 1686 if (i == d) 1687 break; 1688 } 1689 mutex_exit(&mg->mg_lock); 1690 if (msp == NULL) 1691 return (-1ULL); 1692 1693 mutex_enter(&msp->ms_lock); 1694 1695 /* 1696 * Ensure that the metaslab we have selected is still 1697 * capable of handling our request. It's possible that 1698 * another thread may have changed the weight while we 1699 * were blocked on the metaslab lock. 1700 */ 1701 if (msp->ms_weight < asize || (was_active && 1702 !(msp->ms_weight & METASLAB_ACTIVE_MASK) && 1703 activation_weight == METASLAB_WEIGHT_PRIMARY)) { 1704 mutex_exit(&msp->ms_lock); 1705 continue; 1706 } 1707 1708 if ((msp->ms_weight & METASLAB_WEIGHT_SECONDARY) && 1709 activation_weight == METASLAB_WEIGHT_PRIMARY) { 1710 metaslab_passivate(msp, 1711 msp->ms_weight & ~METASLAB_ACTIVE_MASK); 1712 mutex_exit(&msp->ms_lock); 1713 continue; 1714 } 1715 1716 if (metaslab_activate(msp, activation_weight) != 0) { 1717 mutex_exit(&msp->ms_lock); 1718 continue; 1719 } 1720 1721 /* 1722 * If this metaslab is currently condensing then pick again as 1723 * we can't manipulate this metaslab until it's committed 1724 * to disk. 1725 */ 1726 if (msp->ms_condensing) { 1727 mutex_exit(&msp->ms_lock); 1728 continue; 1729 } 1730 1731 if ((offset = metaslab_block_alloc(msp, asize)) != -1ULL) 1732 break; 1733 1734 metaslab_passivate(msp, metaslab_block_maxsize(msp)); 1735 mutex_exit(&msp->ms_lock); 1736 } 1737 1738 if (range_tree_space(msp->ms_alloctree[txg & TXG_MASK]) == 0) 1739 vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg); 1740 1741 range_tree_add(msp->ms_alloctree[txg & TXG_MASK], offset, asize); 1742 msp->ms_access_txg = txg + metaslab_unload_delay; 1743 1744 mutex_exit(&msp->ms_lock); 1745 1746 return (offset); 1747 } 1748 1749 /* 1750 * Allocate a block for the specified i/o. 1751 */ 1752 static int 1753 metaslab_alloc_dva(spa_t *spa, metaslab_class_t *mc, uint64_t psize, 1754 dva_t *dva, int d, dva_t *hintdva, uint64_t txg, int flags) 1755 { 1756 metaslab_group_t *mg, *rotor; 1757 vdev_t *vd; 1758 int dshift = 3; 1759 int all_zero; 1760 int zio_lock = B_FALSE; 1761 boolean_t allocatable; 1762 uint64_t offset = -1ULL; 1763 uint64_t asize; 1764 uint64_t distance; 1765 1766 ASSERT(!DVA_IS_VALID(&dva[d])); 1767 1768 /* 1769 * For testing, make some blocks above a certain size be gang blocks. 1770 */ 1771 if (psize >= metaslab_gang_bang && (ddi_get_lbolt() & 3) == 0) 1772 return (SET_ERROR(ENOSPC)); 1773 1774 /* 1775 * Start at the rotor and loop through all mgs until we find something. 1776 * Note that there's no locking on mc_rotor or mc_aliquot because 1777 * nothing actually breaks if we miss a few updates -- we just won't 1778 * allocate quite as evenly. It all balances out over time. 1779 * 1780 * If we are doing ditto or log blocks, try to spread them across 1781 * consecutive vdevs. If we're forced to reuse a vdev before we've 1782 * allocated all of our ditto blocks, then try and spread them out on 1783 * that vdev as much as possible. If it turns out to not be possible, 1784 * gradually lower our standards until anything becomes acceptable. 1785 * Also, allocating on consecutive vdevs (as opposed to random vdevs) 1786 * gives us hope of containing our fault domains to something we're 1787 * able to reason about. Otherwise, any two top-level vdev failures 1788 * will guarantee the loss of data. With consecutive allocation, 1789 * only two adjacent top-level vdev failures will result in data loss. 1790 * 1791 * If we are doing gang blocks (hintdva is non-NULL), try to keep 1792 * ourselves on the same vdev as our gang block header. That 1793 * way, we can hope for locality in vdev_cache, plus it makes our 1794 * fault domains something tractable. 1795 */ 1796 if (hintdva) { 1797 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&hintdva[d])); 1798 1799 /* 1800 * It's possible the vdev we're using as the hint no 1801 * longer exists (i.e. removed). Consult the rotor when 1802 * all else fails. 1803 */ 1804 if (vd != NULL) { 1805 mg = vd->vdev_mg; 1806 1807 if (flags & METASLAB_HINTBP_AVOID && 1808 mg->mg_next != NULL) 1809 mg = mg->mg_next; 1810 } else { 1811 mg = mc->mc_rotor; 1812 } 1813 } else if (d != 0) { 1814 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[d - 1])); 1815 mg = vd->vdev_mg->mg_next; 1816 } else { 1817 mg = mc->mc_rotor; 1818 } 1819 1820 /* 1821 * If the hint put us into the wrong metaslab class, or into a 1822 * metaslab group that has been passivated, just follow the rotor. 1823 */ 1824 if (mg->mg_class != mc || mg->mg_activation_count <= 0) 1825 mg = mc->mc_rotor; 1826 1827 rotor = mg; 1828 top: 1829 all_zero = B_TRUE; 1830 do { 1831 ASSERT(mg->mg_activation_count == 1); 1832 1833 vd = mg->mg_vd; 1834 1835 /* 1836 * Don't allocate from faulted devices. 1837 */ 1838 if (zio_lock) { 1839 spa_config_enter(spa, SCL_ZIO, FTAG, RW_READER); 1840 allocatable = vdev_allocatable(vd); 1841 spa_config_exit(spa, SCL_ZIO, FTAG); 1842 } else { 1843 allocatable = vdev_allocatable(vd); 1844 } 1845 1846 /* 1847 * Determine if the selected metaslab group is eligible 1848 * for allocations. If we're ganging or have requested 1849 * an allocation for the smallest gang block size 1850 * then we don't want to avoid allocating to the this 1851 * metaslab group. If we're in this condition we should 1852 * try to allocate from any device possible so that we 1853 * don't inadvertently return ENOSPC and suspend the pool 1854 * even though space is still available. 1855 */ 1856 if (allocatable && CAN_FASTGANG(flags) && 1857 psize > SPA_GANGBLOCKSIZE) 1858 allocatable = metaslab_group_allocatable(mg); 1859 1860 if (!allocatable) 1861 goto next; 1862 1863 /* 1864 * Avoid writing single-copy data to a failing vdev 1865 * unless the user instructs us that it is okay. 1866 */ 1867 if ((vd->vdev_stat.vs_write_errors > 0 || 1868 vd->vdev_state < VDEV_STATE_HEALTHY) && 1869 d == 0 && dshift == 3 && 1870 !(zfs_write_to_degraded && vd->vdev_state == 1871 VDEV_STATE_DEGRADED)) { 1872 all_zero = B_FALSE; 1873 goto next; 1874 } 1875 1876 ASSERT(mg->mg_class == mc); 1877 1878 distance = vd->vdev_asize >> dshift; 1879 if (distance <= (1ULL << vd->vdev_ms_shift)) 1880 distance = 0; 1881 else 1882 all_zero = B_FALSE; 1883 1884 asize = vdev_psize_to_asize(vd, psize); 1885 ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0); 1886 1887 offset = metaslab_group_alloc(mg, psize, asize, txg, distance, 1888 dva, d); 1889 if (offset != -1ULL) { 1890 /* 1891 * If we've just selected this metaslab group, 1892 * figure out whether the corresponding vdev is 1893 * over- or under-used relative to the pool, 1894 * and set an allocation bias to even it out. 1895 */ 1896 if (mc->mc_aliquot == 0) { 1897 vdev_stat_t *vs = &vd->vdev_stat; 1898 int64_t vu, cu; 1899 1900 vu = (vs->vs_alloc * 100) / (vs->vs_space + 1); 1901 cu = (mc->mc_alloc * 100) / (mc->mc_space + 1); 1902 1903 /* 1904 * Calculate how much more or less we should 1905 * try to allocate from this device during 1906 * this iteration around the rotor. 1907 * For example, if a device is 80% full 1908 * and the pool is 20% full then we should 1909 * reduce allocations by 60% on this device. 1910 * 1911 * mg_bias = (20 - 80) * 512K / 100 = -307K 1912 * 1913 * This reduces allocations by 307K for this 1914 * iteration. 1915 */ 1916 mg->mg_bias = ((cu - vu) * 1917 (int64_t)mg->mg_aliquot) / 100; 1918 } 1919 1920 if (atomic_add_64_nv(&mc->mc_aliquot, asize) >= 1921 mg->mg_aliquot + mg->mg_bias) { 1922 mc->mc_rotor = mg->mg_next; 1923 mc->mc_aliquot = 0; 1924 } 1925 1926 DVA_SET_VDEV(&dva[d], vd->vdev_id); 1927 DVA_SET_OFFSET(&dva[d], offset); 1928 DVA_SET_GANG(&dva[d], !!(flags & METASLAB_GANG_HEADER)); 1929 DVA_SET_ASIZE(&dva[d], asize); 1930 1931 return (0); 1932 } 1933 next: 1934 mc->mc_rotor = mg->mg_next; 1935 mc->mc_aliquot = 0; 1936 } while ((mg = mg->mg_next) != rotor); 1937 1938 if (!all_zero) { 1939 dshift++; 1940 ASSERT(dshift < 64); 1941 goto top; 1942 } 1943 1944 if (!allocatable && !zio_lock) { 1945 dshift = 3; 1946 zio_lock = B_TRUE; 1947 goto top; 1948 } 1949 1950 bzero(&dva[d], sizeof (dva_t)); 1951 1952 return (SET_ERROR(ENOSPC)); 1953 } 1954 1955 /* 1956 * Free the block represented by DVA in the context of the specified 1957 * transaction group. 1958 */ 1959 static void 1960 metaslab_free_dva(spa_t *spa, const dva_t *dva, uint64_t txg, boolean_t now) 1961 { 1962 uint64_t vdev = DVA_GET_VDEV(dva); 1963 uint64_t offset = DVA_GET_OFFSET(dva); 1964 uint64_t size = DVA_GET_ASIZE(dva); 1965 vdev_t *vd; 1966 metaslab_t *msp; 1967 1968 ASSERT(DVA_IS_VALID(dva)); 1969 1970 if (txg > spa_freeze_txg(spa)) 1971 return; 1972 1973 if ((vd = vdev_lookup_top(spa, vdev)) == NULL || 1974 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count) { 1975 cmn_err(CE_WARN, "metaslab_free_dva(): bad DVA %llu:%llu", 1976 (u_longlong_t)vdev, (u_longlong_t)offset); 1977 ASSERT(0); 1978 return; 1979 } 1980 1981 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift]; 1982 1983 if (DVA_GET_GANG(dva)) 1984 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 1985 1986 mutex_enter(&msp->ms_lock); 1987 1988 if (now) { 1989 range_tree_remove(msp->ms_alloctree[txg & TXG_MASK], 1990 offset, size); 1991 1992 VERIFY(!msp->ms_condensing); 1993 VERIFY3U(offset, >=, msp->ms_start); 1994 VERIFY3U(offset + size, <=, msp->ms_start + msp->ms_size); 1995 VERIFY3U(range_tree_space(msp->ms_tree) + size, <=, 1996 msp->ms_size); 1997 VERIFY0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); 1998 VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift)); 1999 range_tree_add(msp->ms_tree, offset, size); 2000 } else { 2001 if (range_tree_space(msp->ms_freetree[txg & TXG_MASK]) == 0) 2002 vdev_dirty(vd, VDD_METASLAB, msp, txg); 2003 range_tree_add(msp->ms_freetree[txg & TXG_MASK], 2004 offset, size); 2005 } 2006 2007 mutex_exit(&msp->ms_lock); 2008 } 2009 2010 /* 2011 * Intent log support: upon opening the pool after a crash, notify the SPA 2012 * of blocks that the intent log has allocated for immediate write, but 2013 * which are still considered free by the SPA because the last transaction 2014 * group didn't commit yet. 2015 */ 2016 static int 2017 metaslab_claim_dva(spa_t *spa, const dva_t *dva, uint64_t txg) 2018 { 2019 uint64_t vdev = DVA_GET_VDEV(dva); 2020 uint64_t offset = DVA_GET_OFFSET(dva); 2021 uint64_t size = DVA_GET_ASIZE(dva); 2022 vdev_t *vd; 2023 metaslab_t *msp; 2024 int error = 0; 2025 2026 ASSERT(DVA_IS_VALID(dva)); 2027 2028 if ((vd = vdev_lookup_top(spa, vdev)) == NULL || 2029 (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count) 2030 return (SET_ERROR(ENXIO)); 2031 2032 msp = vd->vdev_ms[offset >> vd->vdev_ms_shift]; 2033 2034 if (DVA_GET_GANG(dva)) 2035 size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 2036 2037 mutex_enter(&msp->ms_lock); 2038 2039 if ((txg != 0 && spa_writeable(spa)) || !msp->ms_loaded) 2040 error = metaslab_activate(msp, METASLAB_WEIGHT_SECONDARY); 2041 2042 if (error == 0 && !range_tree_contains(msp->ms_tree, offset, size)) 2043 error = SET_ERROR(ENOENT); 2044 2045 if (error || txg == 0) { /* txg == 0 indicates dry run */ 2046 mutex_exit(&msp->ms_lock); 2047 return (error); 2048 } 2049 2050 VERIFY(!msp->ms_condensing); 2051 VERIFY0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); 2052 VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift)); 2053 VERIFY3U(range_tree_space(msp->ms_tree) - size, <=, msp->ms_size); 2054 range_tree_remove(msp->ms_tree, offset, size); 2055 2056 if (spa_writeable(spa)) { /* don't dirty if we're zdb(1M) */ 2057 if (range_tree_space(msp->ms_alloctree[txg & TXG_MASK]) == 0) 2058 vdev_dirty(vd, VDD_METASLAB, msp, txg); 2059 range_tree_add(msp->ms_alloctree[txg & TXG_MASK], offset, size); 2060 } 2061 2062 mutex_exit(&msp->ms_lock); 2063 2064 return (0); 2065 } 2066 2067 int 2068 metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp, 2069 int ndvas, uint64_t txg, blkptr_t *hintbp, int flags) 2070 { 2071 dva_t *dva = bp->blk_dva; 2072 dva_t *hintdva = hintbp->blk_dva; 2073 int error = 0; 2074 2075 ASSERT(bp->blk_birth == 0); 2076 ASSERT(BP_PHYSICAL_BIRTH(bp) == 0); 2077 2078 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER); 2079 2080 if (mc->mc_rotor == NULL) { /* no vdevs in this class */ 2081 spa_config_exit(spa, SCL_ALLOC, FTAG); 2082 return (SET_ERROR(ENOSPC)); 2083 } 2084 2085 ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa)); 2086 ASSERT(BP_GET_NDVAS(bp) == 0); 2087 ASSERT(hintbp == NULL || ndvas <= BP_GET_NDVAS(hintbp)); 2088 2089 for (int d = 0; d < ndvas; d++) { 2090 error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva, 2091 txg, flags); 2092 if (error != 0) { 2093 for (d--; d >= 0; d--) { 2094 metaslab_free_dva(spa, &dva[d], txg, B_TRUE); 2095 bzero(&dva[d], sizeof (dva_t)); 2096 } 2097 spa_config_exit(spa, SCL_ALLOC, FTAG); 2098 return (error); 2099 } 2100 } 2101 ASSERT(error == 0); 2102 ASSERT(BP_GET_NDVAS(bp) == ndvas); 2103 2104 spa_config_exit(spa, SCL_ALLOC, FTAG); 2105 2106 BP_SET_BIRTH(bp, txg, txg); 2107 2108 return (0); 2109 } 2110 2111 void 2112 metaslab_free(spa_t *spa, const blkptr_t *bp, uint64_t txg, boolean_t now) 2113 { 2114 const dva_t *dva = bp->blk_dva; 2115 int ndvas = BP_GET_NDVAS(bp); 2116 2117 ASSERT(!BP_IS_HOLE(bp)); 2118 ASSERT(!now || bp->blk_birth >= spa_syncing_txg(spa)); 2119 2120 spa_config_enter(spa, SCL_FREE, FTAG, RW_READER); 2121 2122 for (int d = 0; d < ndvas; d++) 2123 metaslab_free_dva(spa, &dva[d], txg, now); 2124 2125 spa_config_exit(spa, SCL_FREE, FTAG); 2126 } 2127 2128 int 2129 metaslab_claim(spa_t *spa, const blkptr_t *bp, uint64_t txg) 2130 { 2131 const dva_t *dva = bp->blk_dva; 2132 int ndvas = BP_GET_NDVAS(bp); 2133 int error = 0; 2134 2135 ASSERT(!BP_IS_HOLE(bp)); 2136 2137 if (txg != 0) { 2138 /* 2139 * First do a dry run to make sure all DVAs are claimable, 2140 * so we don't have to unwind from partial failures below. 2141 */ 2142 if ((error = metaslab_claim(spa, bp, 0)) != 0) 2143 return (error); 2144 } 2145 2146 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER); 2147 2148 for (int d = 0; d < ndvas; d++) 2149 if ((error = metaslab_claim_dva(spa, &dva[d], txg)) != 0) 2150 break; 2151 2152 spa_config_exit(spa, SCL_ALLOC, FTAG); 2153 2154 ASSERT(error == 0 || txg == 0); 2155 2156 return (error); 2157 } 2158 2159 void 2160 metaslab_check_free(spa_t *spa, const blkptr_t *bp) 2161 { 2162 if ((zfs_flags & ZFS_DEBUG_ZIO_FREE) == 0) 2163 return; 2164 2165 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); 2166 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 2167 uint64_t vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 2168 vdev_t *vd = vdev_lookup_top(spa, vdev); 2169 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 2170 uint64_t size = DVA_GET_ASIZE(&bp->blk_dva[i]); 2171 metaslab_t *msp = vd->vdev_ms[offset >> vd->vdev_ms_shift]; 2172 2173 if (msp->ms_loaded) 2174 range_tree_verify(msp->ms_tree, offset, size); 2175 2176 for (int j = 0; j < TXG_SIZE; j++) 2177 range_tree_verify(msp->ms_freetree[j], offset, size); 2178 for (int j = 0; j < TXG_DEFER_SIZE; j++) 2179 range_tree_verify(msp->ms_defertree[j], offset, size); 2180 } 2181 spa_config_exit(spa, SCL_VDEV, FTAG); 2182 } 2183