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 /* 14 * HOW DOES SPACE RESERVATION WORK 15 * 16 * If you want to know about delalloc specifically, there is a separate comment 17 * for that with the delalloc code. This comment is about how the whole system 18 * works generally. 19 * 20 * BASIC CONCEPTS 21 * 22 * 1) space_info. This is the ultimate arbiter of how much space we can use. 23 * There's a description of the bytes_ fields with the struct declaration, 24 * refer to that for specifics on each field. Suffice it to say that for 25 * reservations we care about total_bytes - SUM(space_info->bytes_) when 26 * determining if there is space to make an allocation. There is a space_info 27 * for METADATA, SYSTEM, and DATA areas. 28 * 29 * 2) block_rsv's. These are basically buckets for every different type of 30 * metadata reservation we have. You can see the comment in the block_rsv 31 * code on the rules for each type, but generally block_rsv->reserved is how 32 * much space is accounted for in space_info->bytes_may_use. 33 * 34 * 3) btrfs_calc*_size. These are the worst case calculations we used based 35 * on the number of items we will want to modify. We have one for changing 36 * items, and one for inserting new items. Generally we use these helpers to 37 * determine the size of the block reserves, and then use the actual bytes 38 * values to adjust the space_info counters. 39 * 40 * MAKING RESERVATIONS, THE NORMAL CASE 41 * 42 * We call into either btrfs_reserve_data_bytes() or 43 * btrfs_reserve_metadata_bytes(), depending on which we're looking for, with 44 * num_bytes we want to reserve. 45 * 46 * ->reserve 47 * space_info->bytes_may_reserve += num_bytes 48 * 49 * ->extent allocation 50 * Call btrfs_add_reserved_bytes() which does 51 * space_info->bytes_may_reserve -= num_bytes 52 * space_info->bytes_reserved += extent_bytes 53 * 54 * ->insert reference 55 * Call btrfs_update_block_group() which does 56 * space_info->bytes_reserved -= extent_bytes 57 * space_info->bytes_used += extent_bytes 58 * 59 * MAKING RESERVATIONS, FLUSHING NORMALLY (non-priority) 60 * 61 * Assume we are unable to simply make the reservation because we do not have 62 * enough space 63 * 64 * -> __reserve_bytes 65 * create a reserve_ticket with ->bytes set to our reservation, add it to 66 * the tail of space_info->tickets, kick async flush thread 67 * 68 * ->handle_reserve_ticket 69 * wait on ticket->wait for ->bytes to be reduced to 0, or ->error to be set 70 * on the ticket. 71 * 72 * -> btrfs_async_reclaim_metadata_space/btrfs_async_reclaim_data_space 73 * Flushes various things attempting to free up space. 74 * 75 * -> btrfs_try_granting_tickets() 76 * This is called by anything that either subtracts space from 77 * space_info->bytes_may_use, ->bytes_pinned, etc, or adds to the 78 * space_info->total_bytes. This loops through the ->priority_tickets and 79 * then the ->tickets list checking to see if the reservation can be 80 * completed. If it can the space is added to space_info->bytes_may_use and 81 * the ticket is woken up. 82 * 83 * -> ticket wakeup 84 * Check if ->bytes == 0, if it does we got our reservation and we can carry 85 * on, if not return the appropriate error (ENOSPC, but can be EINTR if we 86 * were interrupted.) 87 * 88 * MAKING RESERVATIONS, FLUSHING HIGH PRIORITY 89 * 90 * Same as the above, except we add ourselves to the 91 * space_info->priority_tickets, and we do not use ticket->wait, we simply 92 * call flush_space() ourselves for the states that are safe for us to call 93 * without deadlocking and hope for the best. 94 * 95 * THE FLUSHING STATES 96 * 97 * Generally speaking we will have two cases for each state, a "nice" state 98 * and a "ALL THE THINGS" state. In btrfs we delay a lot of work in order to 99 * reduce the locking over head on the various trees, and even to keep from 100 * doing any work at all in the case of delayed refs. Each of these delayed 101 * things however hold reservations, and so letting them run allows us to 102 * reclaim space so we can make new reservations. 103 * 104 * FLUSH_DELAYED_ITEMS 105 * Every inode has a delayed item to update the inode. Take a simple write 106 * for example, we would update the inode item at write time to update the 107 * mtime, and then again at finish_ordered_io() time in order to update the 108 * isize or bytes. We keep these delayed items to coalesce these operations 109 * into a single operation done on demand. These are an easy way to reclaim 110 * metadata space. 111 * 112 * FLUSH_DELALLOC 113 * Look at the delalloc comment to get an idea of how much space is reserved 114 * for delayed allocation. We can reclaim some of this space simply by 115 * running delalloc, but usually we need to wait for ordered extents to 116 * reclaim the bulk of this space. 117 * 118 * FLUSH_DELAYED_REFS 119 * We have a block reserve for the outstanding delayed refs space, and every 120 * delayed ref operation holds a reservation. Running these is a quick way 121 * to reclaim space, but we want to hold this until the end because COW can 122 * churn a lot and we can avoid making some extent tree modifications if we 123 * are able to delay for as long as possible. 124 * 125 * ALLOC_CHUNK 126 * We will skip this the first time through space reservation, because of 127 * overcommit and we don't want to have a lot of useless metadata space when 128 * our worst case reservations will likely never come true. 129 * 130 * RUN_DELAYED_IPUTS 131 * If we're freeing inodes we're likely freeing checksums, file extent 132 * items, and extent tree items. Loads of space could be freed up by these 133 * operations, however they won't be usable until the transaction commits. 134 * 135 * COMMIT_TRANS 136 * may_commit_transaction() is the ultimate arbiter on whether we commit the 137 * transaction or not. In order to avoid constantly churning we do all the 138 * above flushing first and then commit the transaction as the last resort. 139 * However we need to take into account things like pinned space that would 140 * be freed, plus any delayed work we may not have gotten rid of in the case 141 * of metadata. 142 * 143 * OVERCOMMIT 144 * 145 * Because we hold so many reservations for metadata we will allow you to 146 * reserve more space than is currently free in the currently allocate 147 * metadata space. This only happens with metadata, data does not allow 148 * overcommitting. 149 * 150 * You can see the current logic for when we allow overcommit in 151 * btrfs_can_overcommit(), but it only applies to unallocated space. If there 152 * is no unallocated space to be had, all reservations are kept within the 153 * free space in the allocated metadata chunks. 154 * 155 * Because of overcommitting, you generally want to use the 156 * btrfs_can_overcommit() logic for metadata allocations, as it does the right 157 * thing with or without extra unallocated space. 158 */ 159 160 u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info, 161 bool may_use_included) 162 { 163 ASSERT(s_info); 164 return s_info->bytes_used + s_info->bytes_reserved + 165 s_info->bytes_pinned + s_info->bytes_readonly + 166 (may_use_included ? s_info->bytes_may_use : 0); 167 } 168 169 /* 170 * after adding space to the filesystem, we need to clear the full flags 171 * on all the space infos. 172 */ 173 void btrfs_clear_space_info_full(struct btrfs_fs_info *info) 174 { 175 struct list_head *head = &info->space_info; 176 struct btrfs_space_info *found; 177 178 rcu_read_lock(); 179 list_for_each_entry_rcu(found, head, list) 180 found->full = 0; 181 rcu_read_unlock(); 182 } 183 184 static int create_space_info(struct btrfs_fs_info *info, u64 flags) 185 { 186 187 struct btrfs_space_info *space_info; 188 int i; 189 int ret; 190 191 space_info = kzalloc(sizeof(*space_info), GFP_NOFS); 192 if (!space_info) 193 return -ENOMEM; 194 195 ret = percpu_counter_init(&space_info->total_bytes_pinned, 0, 196 GFP_KERNEL); 197 if (ret) { 198 kfree(space_info); 199 return ret; 200 } 201 202 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) 203 INIT_LIST_HEAD(&space_info->block_groups[i]); 204 init_rwsem(&space_info->groups_sem); 205 spin_lock_init(&space_info->lock); 206 space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; 207 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE; 208 INIT_LIST_HEAD(&space_info->ro_bgs); 209 INIT_LIST_HEAD(&space_info->tickets); 210 INIT_LIST_HEAD(&space_info->priority_tickets); 211 212 ret = btrfs_sysfs_add_space_info_type(info, space_info); 213 if (ret) 214 return ret; 215 216 list_add_rcu(&space_info->list, &info->space_info); 217 if (flags & BTRFS_BLOCK_GROUP_DATA) 218 info->data_sinfo = space_info; 219 220 return ret; 221 } 222 223 int btrfs_init_space_info(struct btrfs_fs_info *fs_info) 224 { 225 struct btrfs_super_block *disk_super; 226 u64 features; 227 u64 flags; 228 int mixed = 0; 229 int ret; 230 231 disk_super = fs_info->super_copy; 232 if (!btrfs_super_root(disk_super)) 233 return -EINVAL; 234 235 features = btrfs_super_incompat_flags(disk_super); 236 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) 237 mixed = 1; 238 239 flags = BTRFS_BLOCK_GROUP_SYSTEM; 240 ret = create_space_info(fs_info, flags); 241 if (ret) 242 goto out; 243 244 if (mixed) { 245 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA; 246 ret = create_space_info(fs_info, flags); 247 } else { 248 flags = BTRFS_BLOCK_GROUP_METADATA; 249 ret = create_space_info(fs_info, flags); 250 if (ret) 251 goto out; 252 253 flags = BTRFS_BLOCK_GROUP_DATA; 254 ret = create_space_info(fs_info, flags); 255 } 256 out: 257 return ret; 258 } 259 260 void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags, 261 u64 total_bytes, u64 bytes_used, 262 u64 bytes_readonly, 263 struct btrfs_space_info **space_info) 264 { 265 struct btrfs_space_info *found; 266 int factor; 267 268 factor = btrfs_bg_type_to_factor(flags); 269 270 found = btrfs_find_space_info(info, flags); 271 ASSERT(found); 272 spin_lock(&found->lock); 273 found->total_bytes += total_bytes; 274 found->disk_total += total_bytes * factor; 275 found->bytes_used += bytes_used; 276 found->disk_used += bytes_used * factor; 277 found->bytes_readonly += bytes_readonly; 278 if (total_bytes > 0) 279 found->full = 0; 280 btrfs_try_granting_tickets(info, found); 281 spin_unlock(&found->lock); 282 *space_info = found; 283 } 284 285 struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info, 286 u64 flags) 287 { 288 struct list_head *head = &info->space_info; 289 struct btrfs_space_info *found; 290 291 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK; 292 293 rcu_read_lock(); 294 list_for_each_entry_rcu(found, head, list) { 295 if (found->flags & flags) { 296 rcu_read_unlock(); 297 return found; 298 } 299 } 300 rcu_read_unlock(); 301 return NULL; 302 } 303 304 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global) 305 { 306 return (global->size << 1); 307 } 308 309 static u64 calc_available_free_space(struct btrfs_fs_info *fs_info, 310 struct btrfs_space_info *space_info, 311 enum btrfs_reserve_flush_enum flush) 312 { 313 u64 profile; 314 u64 avail; 315 int factor; 316 317 if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM) 318 profile = btrfs_system_alloc_profile(fs_info); 319 else 320 profile = btrfs_metadata_alloc_profile(fs_info); 321 322 avail = atomic64_read(&fs_info->free_chunk_space); 323 324 /* 325 * If we have dup, raid1 or raid10 then only half of the free 326 * space is actually usable. For raid56, the space info used 327 * doesn't include the parity drive, so we don't have to 328 * change the math 329 */ 330 factor = btrfs_bg_type_to_factor(profile); 331 avail = div_u64(avail, factor); 332 333 /* 334 * If we aren't flushing all things, let us overcommit up to 335 * 1/2th of the space. If we can flush, don't let us overcommit 336 * too much, let it overcommit up to 1/8 of the space. 337 */ 338 if (flush == BTRFS_RESERVE_FLUSH_ALL) 339 avail >>= 3; 340 else 341 avail >>= 1; 342 return avail; 343 } 344 345 int btrfs_can_overcommit(struct btrfs_fs_info *fs_info, 346 struct btrfs_space_info *space_info, u64 bytes, 347 enum btrfs_reserve_flush_enum flush) 348 { 349 u64 avail; 350 u64 used; 351 352 /* Don't overcommit when in mixed mode */ 353 if (space_info->flags & BTRFS_BLOCK_GROUP_DATA) 354 return 0; 355 356 used = btrfs_space_info_used(space_info, true); 357 avail = calc_available_free_space(fs_info, space_info, flush); 358 359 if (used + bytes < space_info->total_bytes + avail) 360 return 1; 361 return 0; 362 } 363 364 static void remove_ticket(struct btrfs_space_info *space_info, 365 struct reserve_ticket *ticket) 366 { 367 if (!list_empty(&ticket->list)) { 368 list_del_init(&ticket->list); 369 ASSERT(space_info->reclaim_size >= ticket->bytes); 370 space_info->reclaim_size -= ticket->bytes; 371 } 372 } 373 374 /* 375 * This is for space we already have accounted in space_info->bytes_may_use, so 376 * basically when we're returning space from block_rsv's. 377 */ 378 void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info, 379 struct btrfs_space_info *space_info) 380 { 381 struct list_head *head; 382 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH; 383 384 lockdep_assert_held(&space_info->lock); 385 386 head = &space_info->priority_tickets; 387 again: 388 while (!list_empty(head)) { 389 struct reserve_ticket *ticket; 390 u64 used = btrfs_space_info_used(space_info, true); 391 392 ticket = list_first_entry(head, struct reserve_ticket, list); 393 394 /* Check and see if our ticket can be satisified now. */ 395 if ((used + ticket->bytes <= space_info->total_bytes) || 396 btrfs_can_overcommit(fs_info, space_info, ticket->bytes, 397 flush)) { 398 btrfs_space_info_update_bytes_may_use(fs_info, 399 space_info, 400 ticket->bytes); 401 remove_ticket(space_info, ticket); 402 ticket->bytes = 0; 403 space_info->tickets_id++; 404 wake_up(&ticket->wait); 405 } else { 406 break; 407 } 408 } 409 410 if (head == &space_info->priority_tickets) { 411 head = &space_info->tickets; 412 flush = BTRFS_RESERVE_FLUSH_ALL; 413 goto again; 414 } 415 } 416 417 #define DUMP_BLOCK_RSV(fs_info, rsv_name) \ 418 do { \ 419 struct btrfs_block_rsv *__rsv = &(fs_info)->rsv_name; \ 420 spin_lock(&__rsv->lock); \ 421 btrfs_info(fs_info, #rsv_name ": size %llu reserved %llu", \ 422 __rsv->size, __rsv->reserved); \ 423 spin_unlock(&__rsv->lock); \ 424 } while (0) 425 426 static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info, 427 struct btrfs_space_info *info) 428 { 429 lockdep_assert_held(&info->lock); 430 431 btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull", 432 info->flags, 433 info->total_bytes - btrfs_space_info_used(info, true), 434 info->full ? "" : "not "); 435 btrfs_info(fs_info, 436 "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu", 437 info->total_bytes, info->bytes_used, info->bytes_pinned, 438 info->bytes_reserved, info->bytes_may_use, 439 info->bytes_readonly); 440 441 DUMP_BLOCK_RSV(fs_info, global_block_rsv); 442 DUMP_BLOCK_RSV(fs_info, trans_block_rsv); 443 DUMP_BLOCK_RSV(fs_info, chunk_block_rsv); 444 DUMP_BLOCK_RSV(fs_info, delayed_block_rsv); 445 DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv); 446 447 } 448 449 void btrfs_dump_space_info(struct btrfs_fs_info *fs_info, 450 struct btrfs_space_info *info, u64 bytes, 451 int dump_block_groups) 452 { 453 struct btrfs_block_group *cache; 454 int index = 0; 455 456 spin_lock(&info->lock); 457 __btrfs_dump_space_info(fs_info, info); 458 spin_unlock(&info->lock); 459 460 if (!dump_block_groups) 461 return; 462 463 down_read(&info->groups_sem); 464 again: 465 list_for_each_entry(cache, &info->block_groups[index], list) { 466 spin_lock(&cache->lock); 467 btrfs_info(fs_info, 468 "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s", 469 cache->start, cache->length, cache->used, cache->pinned, 470 cache->reserved, cache->ro ? "[readonly]" : ""); 471 spin_unlock(&cache->lock); 472 btrfs_dump_free_space(cache, bytes); 473 } 474 if (++index < BTRFS_NR_RAID_TYPES) 475 goto again; 476 up_read(&info->groups_sem); 477 } 478 479 static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info, 480 u64 to_reclaim) 481 { 482 u64 bytes; 483 u64 nr; 484 485 bytes = btrfs_calc_insert_metadata_size(fs_info, 1); 486 nr = div64_u64(to_reclaim, bytes); 487 if (!nr) 488 nr = 1; 489 return nr; 490 } 491 492 #define EXTENT_SIZE_PER_ITEM SZ_256K 493 494 /* 495 * shrink metadata reservation for delalloc 496 */ 497 static void shrink_delalloc(struct btrfs_fs_info *fs_info, 498 struct btrfs_space_info *space_info, 499 u64 to_reclaim, bool wait_ordered) 500 { 501 struct btrfs_trans_handle *trans; 502 u64 delalloc_bytes; 503 u64 dio_bytes; 504 u64 items; 505 long time_left; 506 int loops; 507 508 /* Calc the number of the pages we need flush for space reservation */ 509 if (to_reclaim == U64_MAX) { 510 items = U64_MAX; 511 } else { 512 /* 513 * to_reclaim is set to however much metadata we need to 514 * reclaim, but reclaiming that much data doesn't really track 515 * exactly, so increase the amount to reclaim by 2x in order to 516 * make sure we're flushing enough delalloc to hopefully reclaim 517 * some metadata reservations. 518 */ 519 items = calc_reclaim_items_nr(fs_info, to_reclaim) * 2; 520 to_reclaim = items * EXTENT_SIZE_PER_ITEM; 521 } 522 523 trans = (struct btrfs_trans_handle *)current->journal_info; 524 525 delalloc_bytes = percpu_counter_sum_positive( 526 &fs_info->delalloc_bytes); 527 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes); 528 if (delalloc_bytes == 0 && dio_bytes == 0) { 529 if (trans) 530 return; 531 if (wait_ordered) 532 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1); 533 return; 534 } 535 536 /* 537 * If we are doing more ordered than delalloc we need to just wait on 538 * ordered extents, otherwise we'll waste time trying to flush delalloc 539 * that likely won't give us the space back we need. 540 */ 541 if (dio_bytes > delalloc_bytes) 542 wait_ordered = true; 543 544 loops = 0; 545 while ((delalloc_bytes || dio_bytes) && loops < 3) { 546 btrfs_start_delalloc_roots(fs_info, items); 547 548 loops++; 549 if (wait_ordered && !trans) { 550 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1); 551 } else { 552 time_left = schedule_timeout_killable(1); 553 if (time_left) 554 break; 555 } 556 557 spin_lock(&space_info->lock); 558 if (list_empty(&space_info->tickets) && 559 list_empty(&space_info->priority_tickets)) { 560 spin_unlock(&space_info->lock); 561 break; 562 } 563 spin_unlock(&space_info->lock); 564 565 delalloc_bytes = percpu_counter_sum_positive( 566 &fs_info->delalloc_bytes); 567 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes); 568 } 569 } 570 571 /** 572 * maybe_commit_transaction - possibly commit the transaction if its ok to 573 * @root - the root we're allocating for 574 * @bytes - the number of bytes we want to reserve 575 * @force - force the commit 576 * 577 * This will check to make sure that committing the transaction will actually 578 * get us somewhere and then commit the transaction if it does. Otherwise it 579 * will return -ENOSPC. 580 */ 581 static int may_commit_transaction(struct btrfs_fs_info *fs_info, 582 struct btrfs_space_info *space_info) 583 { 584 struct reserve_ticket *ticket = NULL; 585 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv; 586 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; 587 struct btrfs_block_rsv *trans_rsv = &fs_info->trans_block_rsv; 588 struct btrfs_trans_handle *trans; 589 u64 bytes_needed; 590 u64 reclaim_bytes = 0; 591 u64 cur_free_bytes = 0; 592 593 trans = (struct btrfs_trans_handle *)current->journal_info; 594 if (trans) 595 return -EAGAIN; 596 597 spin_lock(&space_info->lock); 598 cur_free_bytes = btrfs_space_info_used(space_info, true); 599 if (cur_free_bytes < space_info->total_bytes) 600 cur_free_bytes = space_info->total_bytes - cur_free_bytes; 601 else 602 cur_free_bytes = 0; 603 604 if (!list_empty(&space_info->priority_tickets)) 605 ticket = list_first_entry(&space_info->priority_tickets, 606 struct reserve_ticket, list); 607 else if (!list_empty(&space_info->tickets)) 608 ticket = list_first_entry(&space_info->tickets, 609 struct reserve_ticket, list); 610 bytes_needed = (ticket) ? ticket->bytes : 0; 611 612 if (bytes_needed > cur_free_bytes) 613 bytes_needed -= cur_free_bytes; 614 else 615 bytes_needed = 0; 616 spin_unlock(&space_info->lock); 617 618 if (!bytes_needed) 619 return 0; 620 621 trans = btrfs_join_transaction(fs_info->extent_root); 622 if (IS_ERR(trans)) 623 return PTR_ERR(trans); 624 625 /* 626 * See if there is enough pinned space to make this reservation, or if 627 * we have block groups that are going to be freed, allowing us to 628 * possibly do a chunk allocation the next loop through. 629 */ 630 if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags) || 631 __percpu_counter_compare(&space_info->total_bytes_pinned, 632 bytes_needed, 633 BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0) 634 goto commit; 635 636 /* 637 * See if there is some space in the delayed insertion reservation for 638 * this reservation. 639 */ 640 if (space_info != delayed_rsv->space_info) 641 goto enospc; 642 643 spin_lock(&delayed_rsv->lock); 644 reclaim_bytes += delayed_rsv->reserved; 645 spin_unlock(&delayed_rsv->lock); 646 647 spin_lock(&delayed_refs_rsv->lock); 648 reclaim_bytes += delayed_refs_rsv->reserved; 649 spin_unlock(&delayed_refs_rsv->lock); 650 651 spin_lock(&trans_rsv->lock); 652 reclaim_bytes += trans_rsv->reserved; 653 spin_unlock(&trans_rsv->lock); 654 655 if (reclaim_bytes >= bytes_needed) 656 goto commit; 657 bytes_needed -= reclaim_bytes; 658 659 if (__percpu_counter_compare(&space_info->total_bytes_pinned, 660 bytes_needed, 661 BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0) 662 goto enospc; 663 664 commit: 665 return btrfs_commit_transaction(trans); 666 enospc: 667 btrfs_end_transaction(trans); 668 return -ENOSPC; 669 } 670 671 /* 672 * Try to flush some data based on policy set by @state. This is only advisory 673 * and may fail for various reasons. The caller is supposed to examine the 674 * state of @space_info to detect the outcome. 675 */ 676 static void flush_space(struct btrfs_fs_info *fs_info, 677 struct btrfs_space_info *space_info, u64 num_bytes, 678 int state) 679 { 680 struct btrfs_root *root = fs_info->extent_root; 681 struct btrfs_trans_handle *trans; 682 int nr; 683 int ret = 0; 684 685 switch (state) { 686 case FLUSH_DELAYED_ITEMS_NR: 687 case FLUSH_DELAYED_ITEMS: 688 if (state == FLUSH_DELAYED_ITEMS_NR) 689 nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2; 690 else 691 nr = -1; 692 693 trans = btrfs_join_transaction(root); 694 if (IS_ERR(trans)) { 695 ret = PTR_ERR(trans); 696 break; 697 } 698 ret = btrfs_run_delayed_items_nr(trans, nr); 699 btrfs_end_transaction(trans); 700 break; 701 case FLUSH_DELALLOC: 702 case FLUSH_DELALLOC_WAIT: 703 shrink_delalloc(fs_info, space_info, num_bytes, 704 state == FLUSH_DELALLOC_WAIT); 705 break; 706 case FLUSH_DELAYED_REFS_NR: 707 case FLUSH_DELAYED_REFS: 708 trans = btrfs_join_transaction(root); 709 if (IS_ERR(trans)) { 710 ret = PTR_ERR(trans); 711 break; 712 } 713 if (state == FLUSH_DELAYED_REFS_NR) 714 nr = calc_reclaim_items_nr(fs_info, num_bytes); 715 else 716 nr = 0; 717 btrfs_run_delayed_refs(trans, nr); 718 btrfs_end_transaction(trans); 719 break; 720 case ALLOC_CHUNK: 721 case ALLOC_CHUNK_FORCE: 722 trans = btrfs_join_transaction(root); 723 if (IS_ERR(trans)) { 724 ret = PTR_ERR(trans); 725 break; 726 } 727 ret = btrfs_chunk_alloc(trans, 728 btrfs_get_alloc_profile(fs_info, space_info->flags), 729 (state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE : 730 CHUNK_ALLOC_FORCE); 731 btrfs_end_transaction(trans); 732 if (ret > 0 || ret == -ENOSPC) 733 ret = 0; 734 break; 735 case RUN_DELAYED_IPUTS: 736 /* 737 * If we have pending delayed iputs then we could free up a 738 * bunch of pinned space, so make sure we run the iputs before 739 * we do our pinned bytes check below. 740 */ 741 btrfs_run_delayed_iputs(fs_info); 742 btrfs_wait_on_delayed_iputs(fs_info); 743 break; 744 case COMMIT_TRANS: 745 ret = may_commit_transaction(fs_info, space_info); 746 break; 747 default: 748 ret = -ENOSPC; 749 break; 750 } 751 752 trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state, 753 ret); 754 return; 755 } 756 757 static inline u64 758 btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info, 759 struct btrfs_space_info *space_info) 760 { 761 u64 used; 762 u64 avail; 763 u64 expected; 764 u64 to_reclaim = space_info->reclaim_size; 765 766 lockdep_assert_held(&space_info->lock); 767 768 avail = calc_available_free_space(fs_info, space_info, 769 BTRFS_RESERVE_FLUSH_ALL); 770 used = btrfs_space_info_used(space_info, true); 771 772 /* 773 * We may be flushing because suddenly we have less space than we had 774 * before, and now we're well over-committed based on our current free 775 * space. If that's the case add in our overage so we make sure to put 776 * appropriate pressure on the flushing state machine. 777 */ 778 if (space_info->total_bytes + avail < used) 779 to_reclaim += used - (space_info->total_bytes + avail); 780 781 if (to_reclaim) 782 return to_reclaim; 783 784 to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M); 785 if (btrfs_can_overcommit(fs_info, space_info, to_reclaim, 786 BTRFS_RESERVE_FLUSH_ALL)) 787 return 0; 788 789 used = btrfs_space_info_used(space_info, true); 790 791 if (btrfs_can_overcommit(fs_info, space_info, SZ_1M, 792 BTRFS_RESERVE_FLUSH_ALL)) 793 expected = div_factor_fine(space_info->total_bytes, 95); 794 else 795 expected = div_factor_fine(space_info->total_bytes, 90); 796 797 if (used > expected) 798 to_reclaim = used - expected; 799 else 800 to_reclaim = 0; 801 to_reclaim = min(to_reclaim, space_info->bytes_may_use + 802 space_info->bytes_reserved); 803 return to_reclaim; 804 } 805 806 static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info, 807 struct btrfs_space_info *space_info, 808 u64 used) 809 { 810 u64 thresh = div_factor_fine(space_info->total_bytes, 98); 811 812 /* If we're just plain full then async reclaim just slows us down. */ 813 if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh) 814 return 0; 815 816 if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info)) 817 return 0; 818 819 return (used >= thresh && !btrfs_fs_closing(fs_info) && 820 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)); 821 } 822 823 static bool steal_from_global_rsv(struct btrfs_fs_info *fs_info, 824 struct btrfs_space_info *space_info, 825 struct reserve_ticket *ticket) 826 { 827 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; 828 u64 min_bytes; 829 830 if (global_rsv->space_info != space_info) 831 return false; 832 833 spin_lock(&global_rsv->lock); 834 min_bytes = div_factor(global_rsv->size, 1); 835 if (global_rsv->reserved < min_bytes + ticket->bytes) { 836 spin_unlock(&global_rsv->lock); 837 return false; 838 } 839 global_rsv->reserved -= ticket->bytes; 840 remove_ticket(space_info, ticket); 841 ticket->bytes = 0; 842 wake_up(&ticket->wait); 843 space_info->tickets_id++; 844 if (global_rsv->reserved < global_rsv->size) 845 global_rsv->full = 0; 846 spin_unlock(&global_rsv->lock); 847 848 return true; 849 } 850 851 /* 852 * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets 853 * @fs_info - fs_info for this fs 854 * @space_info - the space info we were flushing 855 * 856 * We call this when we've exhausted our flushing ability and haven't made 857 * progress in satisfying tickets. The reservation code handles tickets in 858 * order, so if there is a large ticket first and then smaller ones we could 859 * very well satisfy the smaller tickets. This will attempt to wake up any 860 * tickets in the list to catch this case. 861 * 862 * This function returns true if it was able to make progress by clearing out 863 * other tickets, or if it stumbles across a ticket that was smaller than the 864 * first ticket. 865 */ 866 static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info, 867 struct btrfs_space_info *space_info) 868 { 869 struct reserve_ticket *ticket; 870 u64 tickets_id = space_info->tickets_id; 871 u64 first_ticket_bytes = 0; 872 873 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { 874 btrfs_info(fs_info, "cannot satisfy tickets, dumping space info"); 875 __btrfs_dump_space_info(fs_info, space_info); 876 } 877 878 while (!list_empty(&space_info->tickets) && 879 tickets_id == space_info->tickets_id) { 880 ticket = list_first_entry(&space_info->tickets, 881 struct reserve_ticket, list); 882 883 if (ticket->steal && 884 steal_from_global_rsv(fs_info, space_info, ticket)) 885 return true; 886 887 /* 888 * may_commit_transaction will avoid committing the transaction 889 * if it doesn't feel like the space reclaimed by the commit 890 * would result in the ticket succeeding. However if we have a 891 * smaller ticket in the queue it may be small enough to be 892 * satisified by committing the transaction, so if any 893 * subsequent ticket is smaller than the first ticket go ahead 894 * and send us back for another loop through the enospc flushing 895 * code. 896 */ 897 if (first_ticket_bytes == 0) 898 first_ticket_bytes = ticket->bytes; 899 else if (first_ticket_bytes > ticket->bytes) 900 return true; 901 902 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) 903 btrfs_info(fs_info, "failing ticket with %llu bytes", 904 ticket->bytes); 905 906 remove_ticket(space_info, ticket); 907 ticket->error = -ENOSPC; 908 wake_up(&ticket->wait); 909 910 /* 911 * We're just throwing tickets away, so more flushing may not 912 * trip over btrfs_try_granting_tickets, so we need to call it 913 * here to see if we can make progress with the next ticket in 914 * the list. 915 */ 916 btrfs_try_granting_tickets(fs_info, space_info); 917 } 918 return (tickets_id != space_info->tickets_id); 919 } 920 921 /* 922 * This is for normal flushers, we can wait all goddamned day if we want to. We 923 * will loop and continuously try to flush as long as we are making progress. 924 * We count progress as clearing off tickets each time we have to loop. 925 */ 926 static void btrfs_async_reclaim_metadata_space(struct work_struct *work) 927 { 928 struct btrfs_fs_info *fs_info; 929 struct btrfs_space_info *space_info; 930 u64 to_reclaim; 931 int flush_state; 932 int commit_cycles = 0; 933 u64 last_tickets_id; 934 935 fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); 936 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); 937 938 spin_lock(&space_info->lock); 939 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); 940 if (!to_reclaim) { 941 space_info->flush = 0; 942 spin_unlock(&space_info->lock); 943 return; 944 } 945 last_tickets_id = space_info->tickets_id; 946 spin_unlock(&space_info->lock); 947 948 flush_state = FLUSH_DELAYED_ITEMS_NR; 949 do { 950 flush_space(fs_info, space_info, to_reclaim, flush_state); 951 spin_lock(&space_info->lock); 952 if (list_empty(&space_info->tickets)) { 953 space_info->flush = 0; 954 spin_unlock(&space_info->lock); 955 return; 956 } 957 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, 958 space_info); 959 if (last_tickets_id == space_info->tickets_id) { 960 flush_state++; 961 } else { 962 last_tickets_id = space_info->tickets_id; 963 flush_state = FLUSH_DELAYED_ITEMS_NR; 964 if (commit_cycles) 965 commit_cycles--; 966 } 967 968 /* 969 * We don't want to force a chunk allocation until we've tried 970 * pretty hard to reclaim space. Think of the case where we 971 * freed up a bunch of space and so have a lot of pinned space 972 * to reclaim. We would rather use that than possibly create a 973 * underutilized metadata chunk. So if this is our first run 974 * through the flushing state machine skip ALLOC_CHUNK_FORCE and 975 * commit the transaction. If nothing has changed the next go 976 * around then we can force a chunk allocation. 977 */ 978 if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles) 979 flush_state++; 980 981 if (flush_state > COMMIT_TRANS) { 982 commit_cycles++; 983 if (commit_cycles > 2) { 984 if (maybe_fail_all_tickets(fs_info, space_info)) { 985 flush_state = FLUSH_DELAYED_ITEMS_NR; 986 commit_cycles--; 987 } else { 988 space_info->flush = 0; 989 } 990 } else { 991 flush_state = FLUSH_DELAYED_ITEMS_NR; 992 } 993 } 994 spin_unlock(&space_info->lock); 995 } while (flush_state <= COMMIT_TRANS); 996 } 997 998 void btrfs_init_async_reclaim_work(struct work_struct *work) 999 { 1000 INIT_WORK(work, btrfs_async_reclaim_metadata_space); 1001 } 1002 1003 static const enum btrfs_flush_state priority_flush_states[] = { 1004 FLUSH_DELAYED_ITEMS_NR, 1005 FLUSH_DELAYED_ITEMS, 1006 ALLOC_CHUNK, 1007 }; 1008 1009 static const enum btrfs_flush_state evict_flush_states[] = { 1010 FLUSH_DELAYED_ITEMS_NR, 1011 FLUSH_DELAYED_ITEMS, 1012 FLUSH_DELAYED_REFS_NR, 1013 FLUSH_DELAYED_REFS, 1014 FLUSH_DELALLOC, 1015 FLUSH_DELALLOC_WAIT, 1016 ALLOC_CHUNK, 1017 COMMIT_TRANS, 1018 }; 1019 1020 static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, 1021 struct btrfs_space_info *space_info, 1022 struct reserve_ticket *ticket, 1023 const enum btrfs_flush_state *states, 1024 int states_nr) 1025 { 1026 u64 to_reclaim; 1027 int flush_state; 1028 1029 spin_lock(&space_info->lock); 1030 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); 1031 if (!to_reclaim) { 1032 spin_unlock(&space_info->lock); 1033 return; 1034 } 1035 spin_unlock(&space_info->lock); 1036 1037 flush_state = 0; 1038 do { 1039 flush_space(fs_info, space_info, to_reclaim, states[flush_state]); 1040 flush_state++; 1041 spin_lock(&space_info->lock); 1042 if (ticket->bytes == 0) { 1043 spin_unlock(&space_info->lock); 1044 return; 1045 } 1046 spin_unlock(&space_info->lock); 1047 } while (flush_state < states_nr); 1048 } 1049 1050 static void wait_reserve_ticket(struct btrfs_fs_info *fs_info, 1051 struct btrfs_space_info *space_info, 1052 struct reserve_ticket *ticket) 1053 1054 { 1055 DEFINE_WAIT(wait); 1056 int ret = 0; 1057 1058 spin_lock(&space_info->lock); 1059 while (ticket->bytes > 0 && ticket->error == 0) { 1060 ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE); 1061 if (ret) { 1062 /* 1063 * Delete us from the list. After we unlock the space 1064 * info, we don't want the async reclaim job to reserve 1065 * space for this ticket. If that would happen, then the 1066 * ticket's task would not known that space was reserved 1067 * despite getting an error, resulting in a space leak 1068 * (bytes_may_use counter of our space_info). 1069 */ 1070 remove_ticket(space_info, ticket); 1071 ticket->error = -EINTR; 1072 break; 1073 } 1074 spin_unlock(&space_info->lock); 1075 1076 schedule(); 1077 1078 finish_wait(&ticket->wait, &wait); 1079 spin_lock(&space_info->lock); 1080 } 1081 spin_unlock(&space_info->lock); 1082 } 1083 1084 /** 1085 * handle_reserve_ticket - do the appropriate flushing and waiting for a ticket 1086 * @fs_info - the fs 1087 * @space_info - the space_info for the reservation 1088 * @ticket - the ticket for the reservation 1089 * @flush - how much we can flush 1090 * 1091 * This does the work of figuring out how to flush for the ticket, waiting for 1092 * the reservation, and returning the appropriate error if there is one. 1093 */ 1094 static int handle_reserve_ticket(struct btrfs_fs_info *fs_info, 1095 struct btrfs_space_info *space_info, 1096 struct reserve_ticket *ticket, 1097 enum btrfs_reserve_flush_enum flush) 1098 { 1099 int ret; 1100 1101 switch (flush) { 1102 case BTRFS_RESERVE_FLUSH_ALL: 1103 case BTRFS_RESERVE_FLUSH_ALL_STEAL: 1104 wait_reserve_ticket(fs_info, space_info, ticket); 1105 break; 1106 case BTRFS_RESERVE_FLUSH_LIMIT: 1107 priority_reclaim_metadata_space(fs_info, space_info, ticket, 1108 priority_flush_states, 1109 ARRAY_SIZE(priority_flush_states)); 1110 break; 1111 case BTRFS_RESERVE_FLUSH_EVICT: 1112 priority_reclaim_metadata_space(fs_info, space_info, ticket, 1113 evict_flush_states, 1114 ARRAY_SIZE(evict_flush_states)); 1115 break; 1116 default: 1117 ASSERT(0); 1118 break; 1119 } 1120 1121 spin_lock(&space_info->lock); 1122 ret = ticket->error; 1123 if (ticket->bytes || ticket->error) { 1124 /* 1125 * We were a priority ticket, so we need to delete ourselves 1126 * from the list. Because we could have other priority tickets 1127 * behind us that require less space, run 1128 * btrfs_try_granting_tickets() to see if their reservations can 1129 * now be made. 1130 */ 1131 if (!list_empty(&ticket->list)) { 1132 remove_ticket(space_info, ticket); 1133 btrfs_try_granting_tickets(fs_info, space_info); 1134 } 1135 1136 if (!ret) 1137 ret = -ENOSPC; 1138 } 1139 spin_unlock(&space_info->lock); 1140 ASSERT(list_empty(&ticket->list)); 1141 /* 1142 * Check that we can't have an error set if the reservation succeeded, 1143 * as that would confuse tasks and lead them to error out without 1144 * releasing reserved space (if an error happens the expectation is that 1145 * space wasn't reserved at all). 1146 */ 1147 ASSERT(!(ticket->bytes == 0 && ticket->error)); 1148 return ret; 1149 } 1150 1151 /* 1152 * This returns true if this flush state will go through the ordinary flushing 1153 * code. 1154 */ 1155 static inline bool is_normal_flushing(enum btrfs_reserve_flush_enum flush) 1156 { 1157 return (flush == BTRFS_RESERVE_FLUSH_ALL) || 1158 (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL); 1159 } 1160 1161 /** 1162 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space 1163 * @root - the root we're allocating for 1164 * @space_info - the space info we want to allocate from 1165 * @orig_bytes - the number of bytes we want 1166 * @flush - whether or not we can flush to make our reservation 1167 * 1168 * This will reserve orig_bytes number of bytes from the space info associated 1169 * with the block_rsv. If there is not enough space it will make an attempt to 1170 * flush out space to make room. It will do this by flushing delalloc if 1171 * possible or committing the transaction. If flush is 0 then no attempts to 1172 * regain reservations will be made and this will fail if there is not enough 1173 * space already. 1174 */ 1175 static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, 1176 struct btrfs_space_info *space_info, 1177 u64 orig_bytes, 1178 enum btrfs_reserve_flush_enum flush) 1179 { 1180 struct reserve_ticket ticket; 1181 u64 used; 1182 int ret = 0; 1183 bool pending_tickets; 1184 1185 ASSERT(orig_bytes); 1186 ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL); 1187 1188 spin_lock(&space_info->lock); 1189 ret = -ENOSPC; 1190 used = btrfs_space_info_used(space_info, true); 1191 1192 /* 1193 * We don't want NO_FLUSH allocations to jump everybody, they can 1194 * generally handle ENOSPC in a different way, so treat them the same as 1195 * normal flushers when it comes to skipping pending tickets. 1196 */ 1197 if (is_normal_flushing(flush) || (flush == BTRFS_RESERVE_NO_FLUSH)) 1198 pending_tickets = !list_empty(&space_info->tickets) || 1199 !list_empty(&space_info->priority_tickets); 1200 else 1201 pending_tickets = !list_empty(&space_info->priority_tickets); 1202 1203 /* 1204 * Carry on if we have enough space (short-circuit) OR call 1205 * can_overcommit() to ensure we can overcommit to continue. 1206 */ 1207 if (!pending_tickets && 1208 ((used + orig_bytes <= space_info->total_bytes) || 1209 btrfs_can_overcommit(fs_info, space_info, orig_bytes, flush))) { 1210 btrfs_space_info_update_bytes_may_use(fs_info, space_info, 1211 orig_bytes); 1212 ret = 0; 1213 } 1214 1215 /* 1216 * If we couldn't make a reservation then setup our reservation ticket 1217 * and kick the async worker if it's not already running. 1218 * 1219 * If we are a priority flusher then we just need to add our ticket to 1220 * the list and we will do our own flushing further down. 1221 */ 1222 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) { 1223 ticket.bytes = orig_bytes; 1224 ticket.error = 0; 1225 space_info->reclaim_size += ticket.bytes; 1226 init_waitqueue_head(&ticket.wait); 1227 ticket.steal = (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL); 1228 if (flush == BTRFS_RESERVE_FLUSH_ALL || 1229 flush == BTRFS_RESERVE_FLUSH_ALL_STEAL) { 1230 list_add_tail(&ticket.list, &space_info->tickets); 1231 if (!space_info->flush) { 1232 space_info->flush = 1; 1233 trace_btrfs_trigger_flush(fs_info, 1234 space_info->flags, 1235 orig_bytes, flush, 1236 "enospc"); 1237 queue_work(system_unbound_wq, 1238 &fs_info->async_reclaim_work); 1239 } 1240 } else { 1241 list_add_tail(&ticket.list, 1242 &space_info->priority_tickets); 1243 } 1244 } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { 1245 used += orig_bytes; 1246 /* 1247 * We will do the space reservation dance during log replay, 1248 * which means we won't have fs_info->fs_root set, so don't do 1249 * the async reclaim as we will panic. 1250 */ 1251 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) && 1252 need_do_async_reclaim(fs_info, space_info, used) && 1253 !work_busy(&fs_info->async_reclaim_work)) { 1254 trace_btrfs_trigger_flush(fs_info, space_info->flags, 1255 orig_bytes, flush, "preempt"); 1256 queue_work(system_unbound_wq, 1257 &fs_info->async_reclaim_work); 1258 } 1259 } 1260 spin_unlock(&space_info->lock); 1261 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH) 1262 return ret; 1263 1264 return handle_reserve_ticket(fs_info, space_info, &ticket, flush); 1265 } 1266 1267 /** 1268 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space 1269 * @root - the root we're allocating for 1270 * @block_rsv - the block_rsv we're allocating for 1271 * @orig_bytes - the number of bytes we want 1272 * @flush - whether or not we can flush to make our reservation 1273 * 1274 * This will reserve orig_bytes number of bytes from the space info associated 1275 * with the block_rsv. If there is not enough space it will make an attempt to 1276 * flush out space to make room. It will do this by flushing delalloc if 1277 * possible or committing the transaction. If flush is 0 then no attempts to 1278 * regain reservations will be made and this will fail if there is not enough 1279 * space already. 1280 */ 1281 int btrfs_reserve_metadata_bytes(struct btrfs_root *root, 1282 struct btrfs_block_rsv *block_rsv, 1283 u64 orig_bytes, 1284 enum btrfs_reserve_flush_enum flush) 1285 { 1286 struct btrfs_fs_info *fs_info = root->fs_info; 1287 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; 1288 int ret; 1289 1290 ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info, 1291 orig_bytes, flush); 1292 if (ret == -ENOSPC && 1293 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) { 1294 if (block_rsv != global_rsv && 1295 !btrfs_block_rsv_use_bytes(global_rsv, orig_bytes)) 1296 ret = 0; 1297 } 1298 if (ret == -ENOSPC) { 1299 trace_btrfs_space_reservation(fs_info, "space_info:enospc", 1300 block_rsv->space_info->flags, 1301 orig_bytes, 1); 1302 1303 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) 1304 btrfs_dump_space_info(fs_info, block_rsv->space_info, 1305 orig_bytes, 0); 1306 } 1307 return ret; 1308 } 1309