1 // SPDX-License-Identifier: GPL-2.0 2 3 #include "misc.h" 4 #include "ctree.h" 5 #include "space-info.h" 6 #include "sysfs.h" 7 #include "volumes.h" 8 #include "free-space-cache.h" 9 #include "ordered-data.h" 10 #include "transaction.h" 11 #include "block-group.h" 12 13 u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info, 14 bool may_use_included) 15 { 16 ASSERT(s_info); 17 return s_info->bytes_used + s_info->bytes_reserved + 18 s_info->bytes_pinned + s_info->bytes_readonly + 19 (may_use_included ? s_info->bytes_may_use : 0); 20 } 21 22 /* 23 * after adding space to the filesystem, we need to clear the full flags 24 * on all the space infos. 25 */ 26 void btrfs_clear_space_info_full(struct btrfs_fs_info *info) 27 { 28 struct list_head *head = &info->space_info; 29 struct btrfs_space_info *found; 30 31 rcu_read_lock(); 32 list_for_each_entry_rcu(found, head, list) 33 found->full = 0; 34 rcu_read_unlock(); 35 } 36 37 static int create_space_info(struct btrfs_fs_info *info, u64 flags) 38 { 39 40 struct btrfs_space_info *space_info; 41 int i; 42 int ret; 43 44 space_info = kzalloc(sizeof(*space_info), GFP_NOFS); 45 if (!space_info) 46 return -ENOMEM; 47 48 ret = percpu_counter_init(&space_info->total_bytes_pinned, 0, 49 GFP_KERNEL); 50 if (ret) { 51 kfree(space_info); 52 return ret; 53 } 54 55 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) 56 INIT_LIST_HEAD(&space_info->block_groups[i]); 57 init_rwsem(&space_info->groups_sem); 58 spin_lock_init(&space_info->lock); 59 space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; 60 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE; 61 INIT_LIST_HEAD(&space_info->ro_bgs); 62 INIT_LIST_HEAD(&space_info->tickets); 63 INIT_LIST_HEAD(&space_info->priority_tickets); 64 65 ret = btrfs_sysfs_add_space_info_type(info, space_info); 66 if (ret) 67 return ret; 68 69 list_add_rcu(&space_info->list, &info->space_info); 70 if (flags & BTRFS_BLOCK_GROUP_DATA) 71 info->data_sinfo = space_info; 72 73 return ret; 74 } 75 76 int btrfs_init_space_info(struct btrfs_fs_info *fs_info) 77 { 78 struct btrfs_super_block *disk_super; 79 u64 features; 80 u64 flags; 81 int mixed = 0; 82 int ret; 83 84 disk_super = fs_info->super_copy; 85 if (!btrfs_super_root(disk_super)) 86 return -EINVAL; 87 88 features = btrfs_super_incompat_flags(disk_super); 89 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) 90 mixed = 1; 91 92 flags = BTRFS_BLOCK_GROUP_SYSTEM; 93 ret = create_space_info(fs_info, flags); 94 if (ret) 95 goto out; 96 97 if (mixed) { 98 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA; 99 ret = create_space_info(fs_info, flags); 100 } else { 101 flags = BTRFS_BLOCK_GROUP_METADATA; 102 ret = create_space_info(fs_info, flags); 103 if (ret) 104 goto out; 105 106 flags = BTRFS_BLOCK_GROUP_DATA; 107 ret = create_space_info(fs_info, flags); 108 } 109 out: 110 return ret; 111 } 112 113 void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags, 114 u64 total_bytes, u64 bytes_used, 115 u64 bytes_readonly, 116 struct btrfs_space_info **space_info) 117 { 118 struct btrfs_space_info *found; 119 int factor; 120 121 factor = btrfs_bg_type_to_factor(flags); 122 123 found = btrfs_find_space_info(info, flags); 124 ASSERT(found); 125 spin_lock(&found->lock); 126 found->total_bytes += total_bytes; 127 found->disk_total += total_bytes * factor; 128 found->bytes_used += bytes_used; 129 found->disk_used += bytes_used * factor; 130 found->bytes_readonly += bytes_readonly; 131 if (total_bytes > 0) 132 found->full = 0; 133 btrfs_try_granting_tickets(info, found); 134 spin_unlock(&found->lock); 135 *space_info = found; 136 } 137 138 struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info, 139 u64 flags) 140 { 141 struct list_head *head = &info->space_info; 142 struct btrfs_space_info *found; 143 144 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK; 145 146 rcu_read_lock(); 147 list_for_each_entry_rcu(found, head, list) { 148 if (found->flags & flags) { 149 rcu_read_unlock(); 150 return found; 151 } 152 } 153 rcu_read_unlock(); 154 return NULL; 155 } 156 157 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global) 158 { 159 return (global->size << 1); 160 } 161 162 int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, 163 struct btrfs_space_info *space_info, u64 bytes, 164 enum btrfs_reserve_flush_enum flush) 165 { 166 u64 profile; 167 u64 avail; 168 u64 used; 169 int factor; 170 171 /* Don't overcommit when in mixed mode. */ 172 if (space_info->flags & BTRFS_BLOCK_GROUP_DATA) 173 return 0; 174 175 if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM) 176 profile = btrfs_system_alloc_profile(fs_info); 177 else 178 profile = btrfs_metadata_alloc_profile(fs_info); 179 180 used = btrfs_space_info_used(space_info, true); 181 avail = atomic64_read(&fs_info->free_chunk_space); 182 183 /* 184 * If we have dup, raid1 or raid10 then only half of the free 185 * space is actually usable. For raid56, the space info used 186 * doesn't include the parity drive, so we don't have to 187 * change the math 188 */ 189 factor = btrfs_bg_type_to_factor(profile); 190 avail = div_u64(avail, factor); 191 192 /* 193 * If we aren't flushing all things, let us overcommit up to 194 * 1/2th of the space. If we can flush, don't let us overcommit 195 * too much, let it overcommit up to 1/8 of the space. 196 */ 197 if (flush == BTRFS_RESERVE_FLUSH_ALL) 198 avail >>= 3; 199 else 200 avail >>= 1; 201 202 if (used + bytes < space_info->total_bytes + avail) 203 return 1; 204 return 0; 205 } 206 207 /* 208 * This is for space we already have accounted in space_info->bytes_may_use, so 209 * basically when we're returning space from block_rsv's. 210 */ 211 void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info, 212 struct btrfs_space_info *space_info) 213 { 214 struct list_head *head; 215 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH; 216 217 lockdep_assert_held(&space_info->lock); 218 219 head = &space_info->priority_tickets; 220 again: 221 while (!list_empty(head)) { 222 struct reserve_ticket *ticket; 223 u64 used = btrfs_space_info_used(space_info, true); 224 225 ticket = list_first_entry(head, struct reserve_ticket, list); 226 227 /* Check and see if our ticket can be satisified now. */ 228 if ((used + ticket->bytes <= space_info->total_bytes) || 229 btrfs_can_overcommit(fs_info, space_info, ticket->bytes, 230 flush)) { 231 btrfs_space_info_update_bytes_may_use(fs_info, 232 space_info, 233 ticket->bytes); 234 list_del_init(&ticket->list); 235 ticket->bytes = 0; 236 space_info->tickets_id++; 237 wake_up(&ticket->wait); 238 } else { 239 break; 240 } 241 } 242 243 if (head == &space_info->priority_tickets) { 244 head = &space_info->tickets; 245 flush = BTRFS_RESERVE_FLUSH_ALL; 246 goto again; 247 } 248 } 249 250 #define DUMP_BLOCK_RSV(fs_info, rsv_name) \ 251 do { \ 252 struct btrfs_block_rsv *__rsv = &(fs_info)->rsv_name; \ 253 spin_lock(&__rsv->lock); \ 254 btrfs_info(fs_info, #rsv_name ": size %llu reserved %llu", \ 255 __rsv->size, __rsv->reserved); \ 256 spin_unlock(&__rsv->lock); \ 257 } while (0) 258 259 static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info, 260 struct btrfs_space_info *info) 261 { 262 lockdep_assert_held(&info->lock); 263 264 btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull", 265 info->flags, 266 info->total_bytes - btrfs_space_info_used(info, true), 267 info->full ? "" : "not "); 268 btrfs_info(fs_info, 269 "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu", 270 info->total_bytes, info->bytes_used, info->bytes_pinned, 271 info->bytes_reserved, info->bytes_may_use, 272 info->bytes_readonly); 273 274 DUMP_BLOCK_RSV(fs_info, global_block_rsv); 275 DUMP_BLOCK_RSV(fs_info, trans_block_rsv); 276 DUMP_BLOCK_RSV(fs_info, chunk_block_rsv); 277 DUMP_BLOCK_RSV(fs_info, delayed_block_rsv); 278 DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv); 279 280 } 281 282 void btrfs_dump_space_info(struct btrfs_fs_info *fs_info, 283 struct btrfs_space_info *info, u64 bytes, 284 int dump_block_groups) 285 { 286 struct btrfs_block_group *cache; 287 int index = 0; 288 289 spin_lock(&info->lock); 290 __btrfs_dump_space_info(fs_info, info); 291 spin_unlock(&info->lock); 292 293 if (!dump_block_groups) 294 return; 295 296 down_read(&info->groups_sem); 297 again: 298 list_for_each_entry(cache, &info->block_groups[index], list) { 299 spin_lock(&cache->lock); 300 btrfs_info(fs_info, 301 "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s", 302 cache->start, cache->length, cache->used, cache->pinned, 303 cache->reserved, cache->ro ? "[readonly]" : ""); 304 btrfs_dump_free_space(cache, bytes); 305 spin_unlock(&cache->lock); 306 } 307 if (++index < BTRFS_NR_RAID_TYPES) 308 goto again; 309 up_read(&info->groups_sem); 310 } 311 312 static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info, 313 unsigned long nr_pages, int nr_items) 314 { 315 struct super_block *sb = fs_info->sb; 316 317 if (down_read_trylock(&sb->s_umount)) { 318 writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE); 319 up_read(&sb->s_umount); 320 } else { 321 /* 322 * We needn't worry the filesystem going from r/w to r/o though 323 * we don't acquire ->s_umount mutex, because the filesystem 324 * should guarantee the delalloc inodes list be empty after 325 * the filesystem is readonly(all dirty pages are written to 326 * the disk). 327 */ 328 btrfs_start_delalloc_roots(fs_info, nr_items); 329 if (!current->journal_info) 330 btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1); 331 } 332 } 333 334 static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info, 335 u64 to_reclaim) 336 { 337 u64 bytes; 338 u64 nr; 339 340 bytes = btrfs_calc_insert_metadata_size(fs_info, 1); 341 nr = div64_u64(to_reclaim, bytes); 342 if (!nr) 343 nr = 1; 344 return nr; 345 } 346 347 #define EXTENT_SIZE_PER_ITEM SZ_256K 348 349 /* 350 * shrink metadata reservation for delalloc 351 */ 352 static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim, 353 u64 orig, bool wait_ordered) 354 { 355 struct btrfs_space_info *space_info; 356 struct btrfs_trans_handle *trans; 357 u64 delalloc_bytes; 358 u64 dio_bytes; 359 u64 async_pages; 360 u64 items; 361 long time_left; 362 unsigned long nr_pages; 363 int loops; 364 365 /* Calc the number of the pages we need flush for space reservation */ 366 items = calc_reclaim_items_nr(fs_info, to_reclaim); 367 to_reclaim = items * EXTENT_SIZE_PER_ITEM; 368 369 trans = (struct btrfs_trans_handle *)current->journal_info; 370 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); 371 372 delalloc_bytes = percpu_counter_sum_positive( 373 &fs_info->delalloc_bytes); 374 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes); 375 if (delalloc_bytes == 0 && dio_bytes == 0) { 376 if (trans) 377 return; 378 if (wait_ordered) 379 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1); 380 return; 381 } 382 383 /* 384 * If we are doing more ordered than delalloc we need to just wait on 385 * ordered extents, otherwise we'll waste time trying to flush delalloc 386 * that likely won't give us the space back we need. 387 */ 388 if (dio_bytes > delalloc_bytes) 389 wait_ordered = true; 390 391 loops = 0; 392 while ((delalloc_bytes || dio_bytes) && loops < 3) { 393 nr_pages = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT; 394 395 /* 396 * Triggers inode writeback for up to nr_pages. This will invoke 397 * ->writepages callback and trigger delalloc filling 398 * (btrfs_run_delalloc_range()). 399 */ 400 btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items); 401 402 /* 403 * We need to wait for the compressed pages to start before 404 * we continue. 405 */ 406 async_pages = atomic_read(&fs_info->async_delalloc_pages); 407 if (!async_pages) 408 goto skip_async; 409 410 /* 411 * Calculate how many compressed pages we want to be written 412 * before we continue. I.e if there are more async pages than we 413 * require wait_event will wait until nr_pages are written. 414 */ 415 if (async_pages <= nr_pages) 416 async_pages = 0; 417 else 418 async_pages -= nr_pages; 419 420 wait_event(fs_info->async_submit_wait, 421 atomic_read(&fs_info->async_delalloc_pages) <= 422 (int)async_pages); 423 skip_async: 424 spin_lock(&space_info->lock); 425 if (list_empty(&space_info->tickets) && 426 list_empty(&space_info->priority_tickets)) { 427 spin_unlock(&space_info->lock); 428 break; 429 } 430 spin_unlock(&space_info->lock); 431 432 loops++; 433 if (wait_ordered && !trans) { 434 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1); 435 } else { 436 time_left = schedule_timeout_killable(1); 437 if (time_left) 438 break; 439 } 440 delalloc_bytes = percpu_counter_sum_positive( 441 &fs_info->delalloc_bytes); 442 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes); 443 } 444 } 445 446 /** 447 * maybe_commit_transaction - possibly commit the transaction if its ok to 448 * @root - the root we're allocating for 449 * @bytes - the number of bytes we want to reserve 450 * @force - force the commit 451 * 452 * This will check to make sure that committing the transaction will actually 453 * get us somewhere and then commit the transaction if it does. Otherwise it 454 * will return -ENOSPC. 455 */ 456 static int may_commit_transaction(struct btrfs_fs_info *fs_info, 457 struct btrfs_space_info *space_info) 458 { 459 struct reserve_ticket *ticket = NULL; 460 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv; 461 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; 462 struct btrfs_trans_handle *trans; 463 u64 bytes_needed; 464 u64 reclaim_bytes = 0; 465 u64 cur_free_bytes = 0; 466 467 trans = (struct btrfs_trans_handle *)current->journal_info; 468 if (trans) 469 return -EAGAIN; 470 471 spin_lock(&space_info->lock); 472 cur_free_bytes = btrfs_space_info_used(space_info, true); 473 if (cur_free_bytes < space_info->total_bytes) 474 cur_free_bytes = space_info->total_bytes - cur_free_bytes; 475 else 476 cur_free_bytes = 0; 477 478 if (!list_empty(&space_info->priority_tickets)) 479 ticket = list_first_entry(&space_info->priority_tickets, 480 struct reserve_ticket, list); 481 else if (!list_empty(&space_info->tickets)) 482 ticket = list_first_entry(&space_info->tickets, 483 struct reserve_ticket, list); 484 bytes_needed = (ticket) ? ticket->bytes : 0; 485 486 if (bytes_needed > cur_free_bytes) 487 bytes_needed -= cur_free_bytes; 488 else 489 bytes_needed = 0; 490 spin_unlock(&space_info->lock); 491 492 if (!bytes_needed) 493 return 0; 494 495 trans = btrfs_join_transaction(fs_info->extent_root); 496 if (IS_ERR(trans)) 497 return PTR_ERR(trans); 498 499 /* 500 * See if there is enough pinned space to make this reservation, or if 501 * we have block groups that are going to be freed, allowing us to 502 * possibly do a chunk allocation the next loop through. 503 */ 504 if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags) || 505 __percpu_counter_compare(&space_info->total_bytes_pinned, 506 bytes_needed, 507 BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0) 508 goto commit; 509 510 /* 511 * See if there is some space in the delayed insertion reservation for 512 * this reservation. 513 */ 514 if (space_info != delayed_rsv->space_info) 515 goto enospc; 516 517 spin_lock(&delayed_rsv->lock); 518 reclaim_bytes += delayed_rsv->reserved; 519 spin_unlock(&delayed_rsv->lock); 520 521 spin_lock(&delayed_refs_rsv->lock); 522 reclaim_bytes += delayed_refs_rsv->reserved; 523 spin_unlock(&delayed_refs_rsv->lock); 524 if (reclaim_bytes >= bytes_needed) 525 goto commit; 526 bytes_needed -= reclaim_bytes; 527 528 if (__percpu_counter_compare(&space_info->total_bytes_pinned, 529 bytes_needed, 530 BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0) 531 goto enospc; 532 533 commit: 534 return btrfs_commit_transaction(trans); 535 enospc: 536 btrfs_end_transaction(trans); 537 return -ENOSPC; 538 } 539 540 /* 541 * Try to flush some data based on policy set by @state. This is only advisory 542 * and may fail for various reasons. The caller is supposed to examine the 543 * state of @space_info to detect the outcome. 544 */ 545 static void flush_space(struct btrfs_fs_info *fs_info, 546 struct btrfs_space_info *space_info, u64 num_bytes, 547 int state) 548 { 549 struct btrfs_root *root = fs_info->extent_root; 550 struct btrfs_trans_handle *trans; 551 int nr; 552 int ret = 0; 553 554 switch (state) { 555 case FLUSH_DELAYED_ITEMS_NR: 556 case FLUSH_DELAYED_ITEMS: 557 if (state == FLUSH_DELAYED_ITEMS_NR) 558 nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2; 559 else 560 nr = -1; 561 562 trans = btrfs_join_transaction(root); 563 if (IS_ERR(trans)) { 564 ret = PTR_ERR(trans); 565 break; 566 } 567 ret = btrfs_run_delayed_items_nr(trans, nr); 568 btrfs_end_transaction(trans); 569 break; 570 case FLUSH_DELALLOC: 571 case FLUSH_DELALLOC_WAIT: 572 shrink_delalloc(fs_info, num_bytes * 2, num_bytes, 573 state == FLUSH_DELALLOC_WAIT); 574 break; 575 case FLUSH_DELAYED_REFS_NR: 576 case FLUSH_DELAYED_REFS: 577 trans = btrfs_join_transaction(root); 578 if (IS_ERR(trans)) { 579 ret = PTR_ERR(trans); 580 break; 581 } 582 if (state == FLUSH_DELAYED_REFS_NR) 583 nr = calc_reclaim_items_nr(fs_info, num_bytes); 584 else 585 nr = 0; 586 btrfs_run_delayed_refs(trans, nr); 587 btrfs_end_transaction(trans); 588 break; 589 case ALLOC_CHUNK: 590 case ALLOC_CHUNK_FORCE: 591 trans = btrfs_join_transaction(root); 592 if (IS_ERR(trans)) { 593 ret = PTR_ERR(trans); 594 break; 595 } 596 ret = btrfs_chunk_alloc(trans, 597 btrfs_metadata_alloc_profile(fs_info), 598 (state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE : 599 CHUNK_ALLOC_FORCE); 600 btrfs_end_transaction(trans); 601 if (ret > 0 || ret == -ENOSPC) 602 ret = 0; 603 break; 604 case RUN_DELAYED_IPUTS: 605 /* 606 * If we have pending delayed iputs then we could free up a 607 * bunch of pinned space, so make sure we run the iputs before 608 * we do our pinned bytes check below. 609 */ 610 btrfs_run_delayed_iputs(fs_info); 611 btrfs_wait_on_delayed_iputs(fs_info); 612 break; 613 case COMMIT_TRANS: 614 ret = may_commit_transaction(fs_info, space_info); 615 break; 616 default: 617 ret = -ENOSPC; 618 break; 619 } 620 621 trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state, 622 ret); 623 return; 624 } 625 626 static inline u64 627 btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info, 628 struct btrfs_space_info *space_info) 629 { 630 struct reserve_ticket *ticket; 631 u64 used; 632 u64 expected; 633 u64 to_reclaim = 0; 634 635 list_for_each_entry(ticket, &space_info->tickets, list) 636 to_reclaim += ticket->bytes; 637 list_for_each_entry(ticket, &space_info->priority_tickets, list) 638 to_reclaim += ticket->bytes; 639 if (to_reclaim) 640 return to_reclaim; 641 642 to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M); 643 if (btrfs_can_overcommit(fs_info, space_info, to_reclaim, 644 BTRFS_RESERVE_FLUSH_ALL)) 645 return 0; 646 647 used = btrfs_space_info_used(space_info, true); 648 649 if (btrfs_can_overcommit(fs_info, space_info, SZ_1M, 650 BTRFS_RESERVE_FLUSH_ALL)) 651 expected = div_factor_fine(space_info->total_bytes, 95); 652 else 653 expected = div_factor_fine(space_info->total_bytes, 90); 654 655 if (used > expected) 656 to_reclaim = used - expected; 657 else 658 to_reclaim = 0; 659 to_reclaim = min(to_reclaim, space_info->bytes_may_use + 660 space_info->bytes_reserved); 661 return to_reclaim; 662 } 663 664 static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info, 665 struct btrfs_space_info *space_info, 666 u64 used) 667 { 668 u64 thresh = div_factor_fine(space_info->total_bytes, 98); 669 670 /* If we're just plain full then async reclaim just slows us down. */ 671 if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh) 672 return 0; 673 674 if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info)) 675 return 0; 676 677 return (used >= thresh && !btrfs_fs_closing(fs_info) && 678 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)); 679 } 680 681 /* 682 * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets 683 * @fs_info - fs_info for this fs 684 * @space_info - the space info we were flushing 685 * 686 * We call this when we've exhausted our flushing ability and haven't made 687 * progress in satisfying tickets. The reservation code handles tickets in 688 * order, so if there is a large ticket first and then smaller ones we could 689 * very well satisfy the smaller tickets. This will attempt to wake up any 690 * tickets in the list to catch this case. 691 * 692 * This function returns true if it was able to make progress by clearing out 693 * other tickets, or if it stumbles across a ticket that was smaller than the 694 * first ticket. 695 */ 696 static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info, 697 struct btrfs_space_info *space_info) 698 { 699 struct reserve_ticket *ticket; 700 u64 tickets_id = space_info->tickets_id; 701 u64 first_ticket_bytes = 0; 702 703 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { 704 btrfs_info(fs_info, "cannot satisfy tickets, dumping space info"); 705 __btrfs_dump_space_info(fs_info, space_info); 706 } 707 708 while (!list_empty(&space_info->tickets) && 709 tickets_id == space_info->tickets_id) { 710 ticket = list_first_entry(&space_info->tickets, 711 struct reserve_ticket, list); 712 713 /* 714 * may_commit_transaction will avoid committing the transaction 715 * if it doesn't feel like the space reclaimed by the commit 716 * would result in the ticket succeeding. However if we have a 717 * smaller ticket in the queue it may be small enough to be 718 * satisified by committing the transaction, so if any 719 * subsequent ticket is smaller than the first ticket go ahead 720 * and send us back for another loop through the enospc flushing 721 * code. 722 */ 723 if (first_ticket_bytes == 0) 724 first_ticket_bytes = ticket->bytes; 725 else if (first_ticket_bytes > ticket->bytes) 726 return true; 727 728 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) 729 btrfs_info(fs_info, "failing ticket with %llu bytes", 730 ticket->bytes); 731 732 list_del_init(&ticket->list); 733 ticket->error = -ENOSPC; 734 wake_up(&ticket->wait); 735 736 /* 737 * We're just throwing tickets away, so more flushing may not 738 * trip over btrfs_try_granting_tickets, so we need to call it 739 * here to see if we can make progress with the next ticket in 740 * the list. 741 */ 742 btrfs_try_granting_tickets(fs_info, space_info); 743 } 744 return (tickets_id != space_info->tickets_id); 745 } 746 747 /* 748 * This is for normal flushers, we can wait all goddamned day if we want to. We 749 * will loop and continuously try to flush as long as we are making progress. 750 * We count progress as clearing off tickets each time we have to loop. 751 */ 752 static void btrfs_async_reclaim_metadata_space(struct work_struct *work) 753 { 754 struct btrfs_fs_info *fs_info; 755 struct btrfs_space_info *space_info; 756 u64 to_reclaim; 757 int flush_state; 758 int commit_cycles = 0; 759 u64 last_tickets_id; 760 761 fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); 762 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); 763 764 spin_lock(&space_info->lock); 765 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); 766 if (!to_reclaim) { 767 space_info->flush = 0; 768 spin_unlock(&space_info->lock); 769 return; 770 } 771 last_tickets_id = space_info->tickets_id; 772 spin_unlock(&space_info->lock); 773 774 flush_state = FLUSH_DELAYED_ITEMS_NR; 775 do { 776 flush_space(fs_info, space_info, to_reclaim, flush_state); 777 spin_lock(&space_info->lock); 778 if (list_empty(&space_info->tickets)) { 779 space_info->flush = 0; 780 spin_unlock(&space_info->lock); 781 return; 782 } 783 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, 784 space_info); 785 if (last_tickets_id == space_info->tickets_id) { 786 flush_state++; 787 } else { 788 last_tickets_id = space_info->tickets_id; 789 flush_state = FLUSH_DELAYED_ITEMS_NR; 790 if (commit_cycles) 791 commit_cycles--; 792 } 793 794 /* 795 * We don't want to force a chunk allocation until we've tried 796 * pretty hard to reclaim space. Think of the case where we 797 * freed up a bunch of space and so have a lot of pinned space 798 * to reclaim. We would rather use that than possibly create a 799 * underutilized metadata chunk. So if this is our first run 800 * through the flushing state machine skip ALLOC_CHUNK_FORCE and 801 * commit the transaction. If nothing has changed the next go 802 * around then we can force a chunk allocation. 803 */ 804 if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles) 805 flush_state++; 806 807 if (flush_state > COMMIT_TRANS) { 808 commit_cycles++; 809 if (commit_cycles > 2) { 810 if (maybe_fail_all_tickets(fs_info, space_info)) { 811 flush_state = FLUSH_DELAYED_ITEMS_NR; 812 commit_cycles--; 813 } else { 814 space_info->flush = 0; 815 } 816 } else { 817 flush_state = FLUSH_DELAYED_ITEMS_NR; 818 } 819 } 820 spin_unlock(&space_info->lock); 821 } while (flush_state <= COMMIT_TRANS); 822 } 823 824 void btrfs_init_async_reclaim_work(struct work_struct *work) 825 { 826 INIT_WORK(work, btrfs_async_reclaim_metadata_space); 827 } 828 829 static const enum btrfs_flush_state priority_flush_states[] = { 830 FLUSH_DELAYED_ITEMS_NR, 831 FLUSH_DELAYED_ITEMS, 832 ALLOC_CHUNK, 833 }; 834 835 static const enum btrfs_flush_state evict_flush_states[] = { 836 FLUSH_DELAYED_ITEMS_NR, 837 FLUSH_DELAYED_ITEMS, 838 FLUSH_DELAYED_REFS_NR, 839 FLUSH_DELAYED_REFS, 840 FLUSH_DELALLOC, 841 FLUSH_DELALLOC_WAIT, 842 ALLOC_CHUNK, 843 COMMIT_TRANS, 844 }; 845 846 static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, 847 struct btrfs_space_info *space_info, 848 struct reserve_ticket *ticket, 849 const enum btrfs_flush_state *states, 850 int states_nr) 851 { 852 u64 to_reclaim; 853 int flush_state; 854 855 spin_lock(&space_info->lock); 856 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); 857 if (!to_reclaim) { 858 spin_unlock(&space_info->lock); 859 return; 860 } 861 spin_unlock(&space_info->lock); 862 863 flush_state = 0; 864 do { 865 flush_space(fs_info, space_info, to_reclaim, states[flush_state]); 866 flush_state++; 867 spin_lock(&space_info->lock); 868 if (ticket->bytes == 0) { 869 spin_unlock(&space_info->lock); 870 return; 871 } 872 spin_unlock(&space_info->lock); 873 } while (flush_state < states_nr); 874 } 875 876 static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, 877 struct btrfs_space_info *space_info, 878 struct reserve_ticket *ticket) 879 880 { 881 DEFINE_WAIT(wait); 882 int ret = 0; 883 884 spin_lock(&space_info->lock); 885 while (ticket->bytes > 0 && ticket->error == 0) { 886 ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE); 887 if (ret) { 888 /* 889 * Delete us from the list. After we unlock the space 890 * info, we don't want the async reclaim job to reserve 891 * space for this ticket. If that would happen, then the 892 * ticket's task would not known that space was reserved 893 * despite getting an error, resulting in a space leak 894 * (bytes_may_use counter of our space_info). 895 */ 896 list_del_init(&ticket->list); 897 ticket->error = -EINTR; 898 break; 899 } 900 spin_unlock(&space_info->lock); 901 902 schedule(); 903 904 finish_wait(&ticket->wait, &wait); 905 spin_lock(&space_info->lock); 906 } 907 spin_unlock(&space_info->lock); 908 } 909 910 /** 911 * handle_reserve_ticket - do the appropriate flushing and waiting for a ticket 912 * @fs_info - the fs 913 * @space_info - the space_info for the reservation 914 * @ticket - the ticket for the reservation 915 * @flush - how much we can flush 916 * 917 * This does the work of figuring out how to flush for the ticket, waiting for 918 * the reservation, and returning the appropriate error if there is one. 919 */ 920 static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, 921 struct btrfs_space_info *space_info, 922 struct reserve_ticket *ticket, 923 enum btrfs_reserve_flush_enum flush) 924 { 925 int ret; 926 927 switch (flush) { 928 case BTRFS_RESERVE_FLUSH_ALL: 929 wait_reserve_ticket(fs_info, space_info, ticket); 930 break; 931 case BTRFS_RESERVE_FLUSH_LIMIT: 932 priority_reclaim_metadata_space(fs_info, space_info, ticket, 933 priority_flush_states, 934 ARRAY_SIZE(priority_flush_states)); 935 break; 936 case BTRFS_RESERVE_FLUSH_EVICT: 937 priority_reclaim_metadata_space(fs_info, space_info, ticket, 938 evict_flush_states, 939 ARRAY_SIZE(evict_flush_states)); 940 break; 941 default: 942 ASSERT(0); 943 break; 944 } 945 946 spin_lock(&space_info->lock); 947 ret = ticket->error; 948 if (ticket->bytes || ticket->error) { 949 /* 950 * Need to delete here for priority tickets. For regular tickets 951 * either the async reclaim job deletes the ticket from the list 952 * or we delete it ourselves at wait_reserve_ticket(). 953 */ 954 list_del_init(&ticket->list); 955 if (!ret) 956 ret = -ENOSPC; 957 } 958 spin_unlock(&space_info->lock); 959 ASSERT(list_empty(&ticket->list)); 960 /* 961 * Check that we can't have an error set if the reservation succeeded, 962 * as that would confuse tasks and lead them to error out without 963 * releasing reserved space (if an error happens the expectation is that 964 * space wasn't reserved at all). 965 */ 966 ASSERT(!(ticket->bytes == 0 && ticket->error)); 967 return ret; 968 } 969 970 /** 971 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space 972 * @root - the root we're allocating for 973 * @space_info - the space info we want to allocate from 974 * @orig_bytes - the number of bytes we want 975 * @flush - whether or not we can flush to make our reservation 976 * 977 * This will reserve orig_bytes number of bytes from the space info associated 978 * with the block_rsv. If there is not enough space it will make an attempt to 979 * flush out space to make room. It will do this by flushing delalloc if 980 * possible or committing the transaction. If flush is 0 then no attempts to 981 * regain reservations will be made and this will fail if there is not enough 982 * space already. 983 */ 984 static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, 985 struct btrfs_space_info *space_info, 986 u64 orig_bytes, 987 enum btrfs_reserve_flush_enum flush) 988 { 989 struct reserve_ticket ticket; 990 u64 used; 991 int ret = 0; 992 bool pending_tickets; 993 994 ASSERT(orig_bytes); 995 ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL); 996 997 spin_lock(&space_info->lock); 998 ret = -ENOSPC; 999 used = btrfs_space_info_used(space_info, true); 1000 pending_tickets = !list_empty(&space_info->tickets) || 1001 !list_empty(&space_info->priority_tickets); 1002 1003 /* 1004 * Carry on if we have enough space (short-circuit) OR call 1005 * can_overcommit() to ensure we can overcommit to continue. 1006 */ 1007 if (!pending_tickets && 1008 ((used + orig_bytes <= space_info->total_bytes) || 1009 btrfs_can_overcommit(fs_info, space_info, orig_bytes, flush))) { 1010 btrfs_space_info_update_bytes_may_use(fs_info, space_info, 1011 orig_bytes); 1012 ret = 0; 1013 } 1014 1015 /* 1016 * If we couldn't make a reservation then setup our reservation ticket 1017 * and kick the async worker if it's not already running. 1018 * 1019 * If we are a priority flusher then we just need to add our ticket to 1020 * the list and we will do our own flushing further down. 1021 */ 1022 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) { 1023 ticket.bytes = orig_bytes; 1024 ticket.error = 0; 1025 init_waitqueue_head(&ticket.wait); 1026 if (flush == BTRFS_RESERVE_FLUSH_ALL) { 1027 list_add_tail(&ticket.list, &space_info->tickets); 1028 if (!space_info->flush) { 1029 space_info->flush = 1; 1030 trace_btrfs_trigger_flush(fs_info, 1031 space_info->flags, 1032 orig_bytes, flush, 1033 "enospc"); 1034 queue_work(system_unbound_wq, 1035 &fs_info->async_reclaim_work); 1036 } 1037 } else { 1038 list_add_tail(&ticket.list, 1039 &space_info->priority_tickets); 1040 } 1041 } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { 1042 used += orig_bytes; 1043 /* 1044 * We will do the space reservation dance during log replay, 1045 * which means we won't have fs_info->fs_root set, so don't do 1046 * the async reclaim as we will panic. 1047 */ 1048 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) && 1049 need_do_async_reclaim(fs_info, space_info, used) && 1050 !work_busy(&fs_info->async_reclaim_work)) { 1051 trace_btrfs_trigger_flush(fs_info, space_info->flags, 1052 orig_bytes, flush, "preempt"); 1053 queue_work(system_unbound_wq, 1054 &fs_info->async_reclaim_work); 1055 } 1056 } 1057 spin_unlock(&space_info->lock); 1058 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH) 1059 return ret; 1060 1061 return handle_reserve_ticket(fs_info, space_info, &ticket, flush); 1062 } 1063 1064 /** 1065 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space 1066 * @root - the root we're allocating for 1067 * @block_rsv - the block_rsv we're allocating for 1068 * @orig_bytes - the number of bytes we want 1069 * @flush - whether or not we can flush to make our reservation 1070 * 1071 * This will reserve orig_bytes number of bytes from the space info associated 1072 * with the block_rsv. If there is not enough space it will make an attempt to 1073 * flush out space to make room. It will do this by flushing delalloc if 1074 * possible or committing the transaction. If flush is 0 then no attempts to 1075 * regain reservations will be made and this will fail if there is not enough 1076 * space already. 1077 */ 1078 int btrfs_reserve_metadata_bytes(struct btrfs_root *root, 1079 struct btrfs_block_rsv *block_rsv, 1080 u64 orig_bytes, 1081 enum btrfs_reserve_flush_enum flush) 1082 { 1083 struct btrfs_fs_info *fs_info = root->fs_info; 1084 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; 1085 int ret; 1086 1087 ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info, 1088 orig_bytes, flush); 1089 if (ret == -ENOSPC && 1090 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) { 1091 if (block_rsv != global_rsv && 1092 !btrfs_block_rsv_use_bytes(global_rsv, orig_bytes)) 1093 ret = 0; 1094 } 1095 if (ret == -ENOSPC) { 1096 trace_btrfs_space_reservation(fs_info, "space_info:enospc", 1097 block_rsv->space_info->flags, 1098 orig_bytes, 1); 1099 1100 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) 1101 btrfs_dump_space_info(fs_info, block_rsv->space_info, 1102 orig_bytes, 0); 1103 } 1104 return ret; 1105 } 1106