btrfs/space-info.c

   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 #include "zoned.h"
  13
  14 /*
  15  * HOW DOES SPACE RESERVATION WORK
  16  *
  17  * If you want to know about delalloc specifically, there is a separate comment
  18  * for that with the delalloc code.  This comment is about how the whole system
  19  * works generally.
  20  *
  21  * BASIC CONCEPTS
  22  *
  23  *   1) space_info.  This is the ultimate arbiter of how much space we can use.
  24  *   There's a description of the bytes_ fields with the struct declaration,
  25  *   refer to that for specifics on each field.  Suffice it to say that for
  26  *   reservations we care about total_bytes - SUM(space_info->bytes_) when
  27  *   determining if there is space to make an allocation.  There is a space_info
  28  *   for METADATA, SYSTEM, and DATA areas.
  29  *
  30  *   2) block_rsv's.  These are basically buckets for every different type of
  31  *   metadata reservation we have.  You can see the comment in the block_rsv
  32  *   code on the rules for each type, but generally block_rsv->reserved is how
  33  *   much space is accounted for in space_info->bytes_may_use.
  34  *
  35  *   3) btrfs_calc*_size.  These are the worst case calculations we used based
  36  *   on the number of items we will want to modify.  We have one for changing
  37  *   items, and one for inserting new items.  Generally we use these helpers to
  38  *   determine the size of the block reserves, and then use the actual bytes
  39  *   values to adjust the space_info counters.
  40  *
  41  * MAKING RESERVATIONS, THE NORMAL CASE
  42  *
  43  *   We call into either btrfs_reserve_data_bytes() or
  44  *   btrfs_reserve_metadata_bytes(), depending on which we're looking for, with
  45  *   num_bytes we want to reserve.
  46  *
  47  *   ->reserve
  48  *     space_info->bytes_may_reserve += num_bytes
  49  *
  50  *   ->extent allocation
  51  *     Call btrfs_add_reserved_bytes() which does
  52  *     space_info->bytes_may_reserve -= num_bytes
  53  *     space_info->bytes_reserved += extent_bytes
  54  *
  55  *   ->insert reference
  56  *     Call btrfs_update_block_group() which does
  57  *     space_info->bytes_reserved -= extent_bytes
  58  *     space_info->bytes_used += extent_bytes
  59  *
  60  * MAKING RESERVATIONS, FLUSHING NORMALLY (non-priority)
  61  *
  62  *   Assume we are unable to simply make the reservation because we do not have
  63  *   enough space
  64  *
  65  *   -> __reserve_bytes
  66  *     create a reserve_ticket with ->bytes set to our reservation, add it to
  67  *     the tail of space_info->tickets, kick async flush thread
  68  *
  69  *   ->handle_reserve_ticket
  70  *     wait on ticket->wait for ->bytes to be reduced to 0, or ->error to be set
  71  *     on the ticket.
  72  *
  73  *   -> btrfs_async_reclaim_metadata_space/btrfs_async_reclaim_data_space
  74  *     Flushes various things attempting to free up space.
  75  *
  76  *   -> btrfs_try_granting_tickets()
  77  *     This is called by anything that either subtracts space from
  78  *     space_info->bytes_may_use, ->bytes_pinned, etc, or adds to the
  79  *     space_info->total_bytes.  This loops through the ->priority_tickets and
  80  *     then the ->tickets list checking to see if the reservation can be
  81  *     completed.  If it can the space is added to space_info->bytes_may_use and
  82  *     the ticket is woken up.
  83  *
  84  *   -> ticket wakeup
  85  *     Check if ->bytes == 0, if it does we got our reservation and we can carry
  86  *     on, if not return the appropriate error (ENOSPC, but can be EINTR if we
  87  *     were interrupted.)
  88  *
  89  * MAKING RESERVATIONS, FLUSHING HIGH PRIORITY
  90  *
  91  *   Same as the above, except we add ourselves to the
  92  *   space_info->priority_tickets, and we do not use ticket->wait, we simply
  93  *   call flush_space() ourselves for the states that are safe for us to call
  94  *   without deadlocking and hope for the best.
  95  *
  96  * THE FLUSHING STATES
  97  *
  98  *   Generally speaking we will have two cases for each state, a "nice" state
  99  *   and a "ALL THE THINGS" state.  In btrfs we delay a lot of work in order to
 100  *   reduce the locking over head on the various trees, and even to keep from
 101  *   doing any work at all in the case of delayed refs.  Each of these delayed
 102  *   things however hold reservations, and so letting them run allows us to
 103  *   reclaim space so we can make new reservations.
 104  *
 105  *   FLUSH_DELAYED_ITEMS
 106  *     Every inode has a delayed item to update the inode.  Take a simple write
 107  *     for example, we would update the inode item at write time to update the
 108  *     mtime, and then again at finish_ordered_io() time in order to update the
 109  *     isize or bytes.  We keep these delayed items to coalesce these operations
 110  *     into a single operation done on demand.  These are an easy way to reclaim
 111  *     metadata space.
 112  *
 113  *   FLUSH_DELALLOC
 114  *     Look at the delalloc comment to get an idea of how much space is reserved
 115  *     for delayed allocation.  We can reclaim some of this space simply by
 116  *     running delalloc, but usually we need to wait for ordered extents to
 117  *     reclaim the bulk of this space.
 118  *
 119  *   FLUSH_DELAYED_REFS
 120  *     We have a block reserve for the outstanding delayed refs space, and every
 121  *     delayed ref operation holds a reservation.  Running these is a quick way
 122  *     to reclaim space, but we want to hold this until the end because COW can
 123  *     churn a lot and we can avoid making some extent tree modifications if we
 124  *     are able to delay for as long as possible.
 125  *
 126  *   ALLOC_CHUNK
 127  *     We will skip this the first time through space reservation, because of
 128  *     overcommit and we don't want to have a lot of useless metadata space when
 129  *     our worst case reservations will likely never come true.
 130  *
 131  *   RUN_DELAYED_IPUTS
 132  *     If we're freeing inodes we're likely freeing checksums, file extent
 133  *     items, and extent tree items.  Loads of space could be freed up by these
 134  *     operations, however they won't be usable until the transaction commits.
 135  *
 136  *   COMMIT_TRANS
 137  *     This will commit the transaction.  Historically we had a lot of logic
 138  *     surrounding whether or not we'd commit the transaction, but this waits born
 139  *     out of a pre-tickets era where we could end up committing the transaction
 140  *     thousands of times in a row without making progress.  Now thanks to our
 141  *     ticketing system we know if we're not making progress and can error
 142  *     everybody out after a few commits rather than burning the disk hoping for
 143  *     a different answer.
 144  *
 145  * OVERCOMMIT
 146  *
 147  *   Because we hold so many reservations for metadata we will allow you to
 148  *   reserve more space than is currently free in the currently allocate
 149  *   metadata space.  This only happens with metadata, data does not allow
 150  *   overcommitting.
 151  *
 152  *   You can see the current logic for when we allow overcommit in
 153  *   btrfs_can_overcommit(), but it only applies to unallocated space.  If there
 154  *   is no unallocated space to be had, all reservations are kept within the
 155  *   free space in the allocated metadata chunks.
 156  *
 157  *   Because of overcommitting, you generally want to use the
 158  *   btrfs_can_overcommit() logic for metadata allocations, as it does the right
 159  *   thing with or without extra unallocated space.
 160  */
 161
 162 u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
 163                           bool may_use_included)
 164 {
 165         ASSERT(s_info);
 166         return s_info->bytes_used + s_info->bytes_reserved +
 167                 s_info->bytes_pinned + s_info->bytes_readonly +
 168                 s_info->bytes_zone_unusable +
 169                 (may_use_included ? s_info->bytes_may_use : 0);
 170 }
 171
 172 /*
 173  * after adding space to the filesystem, we need to clear the full flags
 174  * on all the space infos.
 175  */
 176 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
 177 {
 178         struct list_head *head = &info->space_info;
 179         struct btrfs_space_info *found;
 180
 181         list_for_each_entry(found, head, list)
 182                 found->full = 0;
 183 }
 184
 185 /*
 186  * Block groups with more than this value (percents) of unusable space will be
 187  * scheduled for background reclaim.
 188  */
 189 #define BTRFS_DEFAULT_ZONED_RECLAIM_THRESH                      (75)
 190
 191 /*
 192  * Calculate chunk size depending on volume type (regular or zoned).
 193  */
 194 static u64 calc_chunk_size(const struct btrfs_fs_info *fs_info, u64 flags)
 195 {
 196         if (btrfs_is_zoned(fs_info))
 197                 return fs_info->zone_size;
 198
 199         ASSERT(flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
 200
 201         if (flags & BTRFS_BLOCK_GROUP_DATA)
 202                 return BTRFS_MAX_DATA_CHUNK_SIZE;
 203         else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
 204                 return SZ_32M;
 205
 206         /* Handle BTRFS_BLOCK_GROUP_METADATA */
 207         if (fs_info->fs_devices->total_rw_bytes > 50ULL * SZ_1G)
 208                 return SZ_1G;
 209
 210         return SZ_256M;
 211 }
 212
 213 /*
 214  * Update default chunk size.
 215  */
 216 void btrfs_update_space_info_chunk_size(struct btrfs_space_info *space_info,
 217                                         u64 chunk_size)
 218 {
 219         WRITE_ONCE(space_info->chunk_size, chunk_size);
 220 }
 221
 222 static int create_space_info(struct btrfs_fs_info *info, u64 flags)
 223 {
 224
 225         struct btrfs_space_info *space_info;
 226         int i;
 227         int ret;
 228
 229         space_info = kzalloc(sizeof(*space_info), GFP_NOFS);
 230         if (!space_info)
 231                 return -ENOMEM;
 232
 233         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
 234                 INIT_LIST_HEAD(&space_info->block_groups[i]);
 235         init_rwsem(&space_info->groups_sem);
 236         spin_lock_init(&space_info->lock);
 237         space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
 238         space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
 239         INIT_LIST_HEAD(&space_info->ro_bgs);
 240         INIT_LIST_HEAD(&space_info->tickets);
 241         INIT_LIST_HEAD(&space_info->priority_tickets);
 242         space_info->clamp = 1;
 243         btrfs_update_space_info_chunk_size(space_info, calc_chunk_size(info, flags));
 244
 245         if (btrfs_is_zoned(info))
 246                 space_info->bg_reclaim_threshold = BTRFS_DEFAULT_ZONED_RECLAIM_THRESH;
 247
 248         ret = btrfs_sysfs_add_space_info_type(info, space_info);
 249         if (ret)
 250                 return ret;
 251
 252         list_add(&space_info->list, &info->space_info);
 253         if (flags & BTRFS_BLOCK_GROUP_DATA)
 254                 info->data_sinfo = space_info;
 255
 256         return ret;
 257 }
 258
 259 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
 260 {
 261         struct btrfs_super_block *disk_super;
 262         u64 features;
 263         u64 flags;
 264         int mixed = 0;
 265         int ret;
 266
 267         disk_super = fs_info->super_copy;
 268         if (!btrfs_super_root(disk_super))
 269                 return -EINVAL;
 270
 271         features = btrfs_super_incompat_flags(disk_super);
 272         if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
 273                 mixed = 1;
 274
 275         flags = BTRFS_BLOCK_GROUP_SYSTEM;
 276         ret = create_space_info(fs_info, flags);
 277         if (ret)
 278                 goto out;
 279
 280         if (mixed) {
 281                 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
 282                 ret = create_space_info(fs_info, flags);
 283         } else {
 284                 flags = BTRFS_BLOCK_GROUP_METADATA;
 285                 ret = create_space_info(fs_info, flags);
 286                 if (ret)
 287                         goto out;
 288
 289                 flags = BTRFS_BLOCK_GROUP_DATA;
 290                 ret = create_space_info(fs_info, flags);
 291         }
 292 out:
 293         return ret;
 294 }
 295
 296 void btrfs_add_bg_to_space_info(struct btrfs_fs_info *info,
 297                                 struct btrfs_block_group *block_group)
 298 {
 299         struct btrfs_space_info *found;
 300         int factor, index;
 301
 302         factor = btrfs_bg_type_to_factor(block_group->flags);
 303
 304         found = btrfs_find_space_info(info, block_group->flags);
 305         ASSERT(found);
 306         spin_lock(&found->lock);
 307         found->total_bytes += block_group->length;
 308         if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags))
 309                 found->active_total_bytes += block_group->length;
 310         found->disk_total += block_group->length * factor;
 311         found->bytes_used += block_group->used;
 312         found->disk_used += block_group->used * factor;
 313         found->bytes_readonly += block_group->bytes_super;
 314         found->bytes_zone_unusable += block_group->zone_unusable;
 315         if (block_group->length > 0)
 316                 found->full = 0;
 317         btrfs_try_granting_tickets(info, found);
 318         spin_unlock(&found->lock);
 319
 320         block_group->space_info = found;
 321
 322         index = btrfs_bg_flags_to_raid_index(block_group->flags);
 323         down_write(&found->groups_sem);
 324         list_add_tail(&block_group->list, &found->block_groups[index]);
 325         up_write(&found->groups_sem);
 326 }
 327
 328 struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
 329                                                u64 flags)
 330 {
 331         struct list_head *head = &info->space_info;
 332         struct btrfs_space_info *found;
 333
 334         flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
 335
 336         list_for_each_entry(found, head, list) {
 337                 if (found->flags & flags)
 338                         return found;
 339         }
 340         return NULL;
 341 }
 342
 343 static u64 calc_available_free_space(struct btrfs_fs_info *fs_info,
 344                           struct btrfs_space_info *space_info,
 345                           enum btrfs_reserve_flush_enum flush)
 346 {
 347         u64 profile;
 348         u64 avail;
 349         int factor;
 350
 351         if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
 352                 profile = btrfs_system_alloc_profile(fs_info);
 353         else
 354                 profile = btrfs_metadata_alloc_profile(fs_info);
 355
 356         avail = atomic64_read(&fs_info->free_chunk_space);
 357
 358         /*
 359          * If we have dup, raid1 or raid10 then only half of the free
 360          * space is actually usable.  For raid56, the space info used
 361          * doesn't include the parity drive, so we don't have to
 362          * change the math
 363          */
 364         factor = btrfs_bg_type_to_factor(profile);
 365         avail = div_u64(avail, factor);
 366
 367         /*
 368          * If we aren't flushing all things, let us overcommit up to
 369          * 1/2th of the space. If we can flush, don't let us overcommit
 370          * too much, let it overcommit up to 1/8 of the space.
 371          */
 372         if (flush == BTRFS_RESERVE_FLUSH_ALL)
 373                 avail >>= 3;
 374         else
 375                 avail >>= 1;
 376         return avail;
 377 }
 378
 379 static inline u64 writable_total_bytes(struct btrfs_fs_info *fs_info,
 380                                        struct btrfs_space_info *space_info)
 381 {
 382         /*
 383          * On regular filesystem, all total_bytes are always writable. On zoned
 384          * filesystem, there may be a limitation imposed by max_active_zones.
 385          * For metadata allocation, we cannot finish an existing active block
 386          * group to avoid a deadlock. Thus, we need to consider only the active
 387          * groups to be writable for metadata space.
 388          */
 389         if (!btrfs_is_zoned(fs_info) || (space_info->flags & BTRFS_BLOCK_GROUP_DATA))
 390                 return space_info->total_bytes;
 391
 392         return space_info->active_total_bytes;
 393 }
 394
 395 int btrfs_can_overcommit(struct btrfs_fs_info *fs_info,
 396                          struct btrfs_space_info *space_info, u64 bytes,
 397                          enum btrfs_reserve_flush_enum flush)
 398 {
 399         u64 avail;
 400         u64 used;
 401
 402         /* Don't overcommit when in mixed mode */
 403         if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
 404                 return 0;
 405
 406         used = btrfs_space_info_used(space_info, true);
 407         avail = calc_available_free_space(fs_info, space_info, flush);
 408
 409         if (used + bytes < writable_total_bytes(fs_info, space_info) + avail)
 410                 return 1;
 411         return 0;
 412 }
 413
 414 static void remove_ticket(struct btrfs_space_info *space_info,
 415                           struct reserve_ticket *ticket)
 416 {
 417         if (!list_empty(&ticket->list)) {
 418                 list_del_init(&ticket->list);
 419                 ASSERT(space_info->reclaim_size >= ticket->bytes);
 420                 space_info->reclaim_size -= ticket->bytes;
 421         }
 422 }
 423
 424 /*
 425  * This is for space we already have accounted in space_info->bytes_may_use, so
 426  * basically when we're returning space from block_rsv's.
 427  */
 428 void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
 429                                 struct btrfs_space_info *space_info)
 430 {
 431         struct list_head *head;
 432         enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
 433
 434         lockdep_assert_held(&space_info->lock);
 435
 436         head = &space_info->priority_tickets;
 437 again:
 438         while (!list_empty(head)) {
 439                 struct reserve_ticket *ticket;
 440                 u64 used = btrfs_space_info_used(space_info, true);
 441
 442                 ticket = list_first_entry(head, struct reserve_ticket, list);
 443
 444                 /* Check and see if our ticket can be satisfied now. */
 445                 if ((used + ticket->bytes <= writable_total_bytes(fs_info, space_info)) ||
 446                     btrfs_can_overcommit(fs_info, space_info, ticket->bytes,
 447                                          flush)) {
 448                         btrfs_space_info_update_bytes_may_use(fs_info,
 449                                                               space_info,
 450                                                               ticket->bytes);
 451                         remove_ticket(space_info, ticket);
 452                         ticket->bytes = 0;
 453                         space_info->tickets_id++;
 454                         wake_up(&ticket->wait);
 455                 } else {
 456                         break;
 457                 }
 458         }
 459
 460         if (head == &space_info->priority_tickets) {
 461                 head = &space_info->tickets;
 462                 flush = BTRFS_RESERVE_FLUSH_ALL;
 463                 goto again;
 464         }
 465 }
 466
 467 #define DUMP_BLOCK_RSV(fs_info, rsv_name)                               \
 468 do {                                                                    \
 469         struct btrfs_block_rsv *__rsv = &(fs_info)->rsv_name;           \
 470         spin_lock(&__rsv->lock);                                        \
 471         btrfs_info(fs_info, #rsv_name ": size %llu reserved %llu",      \
 472                    __rsv->size, __rsv->reserved);                       \
 473         spin_unlock(&__rsv->lock);                                      \
 474 } while (0)
 475
 476 static const char *space_info_flag_to_str(const struct btrfs_space_info *space_info)
 477 {
 478         switch (space_info->flags) {
 479         case BTRFS_BLOCK_GROUP_SYSTEM:
 480                 return "SYSTEM";
 481         case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
 482                 return "DATA+METADATA";
 483         case BTRFS_BLOCK_GROUP_DATA:
 484                 return "DATA";
 485         case BTRFS_BLOCK_GROUP_METADATA:
 486                 return "METADATA";
 487         default:
 488                 return "UNKNOWN";
 489         }
 490 }
 491
 492 static void dump_global_block_rsv(struct btrfs_fs_info *fs_info)
 493 {
 494         DUMP_BLOCK_RSV(fs_info, global_block_rsv);
 495         DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
 496         DUMP_BLOCK_RSV(fs_info, chunk_block_rsv);
 497         DUMP_BLOCK_RSV(fs_info, delayed_block_rsv);
 498         DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv);
 499 }
 500
 501 static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
 502                                     struct btrfs_space_info *info)
 503 {
 504         const char *flag_str = space_info_flag_to_str(info);
 505         lockdep_assert_held(&info->lock);
 506
 507         /* The free space could be negative in case of overcommit */
 508         btrfs_info(fs_info, "space_info %s has %lld free, is %sfull",
 509                    flag_str,
 510                    (s64)(info->total_bytes - btrfs_space_info_used(info, true)),
 511                    info->full ? "" : "not ");
 512         btrfs_info(fs_info,
 513 "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu zone_unusable=%llu",
 514                 info->total_bytes, info->bytes_used, info->bytes_pinned,
 515                 info->bytes_reserved, info->bytes_may_use,
 516                 info->bytes_readonly, info->bytes_zone_unusable);
 517 }
 518
 519 void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
 520                            struct btrfs_space_info *info, u64 bytes,
 521                            int dump_block_groups)
 522 {
 523         struct btrfs_block_group *cache;
 524         int index = 0;
 525
 526         spin_lock(&info->lock);
 527         __btrfs_dump_space_info(fs_info, info);
 528         dump_global_block_rsv(fs_info);
 529         spin_unlock(&info->lock);
 530
 531         if (!dump_block_groups)
 532                 return;
 533
 534         down_read(&info->groups_sem);
 535 again:
 536         list_for_each_entry(cache, &info->block_groups[index], list) {
 537                 spin_lock(&cache->lock);
 538                 btrfs_info(fs_info,
 539                         "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %llu zone_unusable %s",
 540                         cache->start, cache->length, cache->used, cache->pinned,
 541                         cache->reserved, cache->zone_unusable,
 542                         cache->ro ? "[readonly]" : "");
 543                 spin_unlock(&cache->lock);
 544                 btrfs_dump_free_space(cache, bytes);
 545         }
 546         if (++index < BTRFS_NR_RAID_TYPES)
 547                 goto again;
 548         up_read(&info->groups_sem);
 549 }
 550
 551 static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
 552                                         u64 to_reclaim)
 553 {
 554         u64 bytes;
 555         u64 nr;
 556
 557         bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 558         nr = div64_u64(to_reclaim, bytes);
 559         if (!nr)
 560                 nr = 1;
 561         return nr;
 562 }
 563
 564 #define EXTENT_SIZE_PER_ITEM    SZ_256K
 565
 566 /*
 567  * shrink metadata reservation for delalloc
 568  */
 569 static void shrink_delalloc(struct btrfs_fs_info *fs_info,
 570                             struct btrfs_space_info *space_info,
 571                             u64 to_reclaim, bool wait_ordered,
 572                             bool for_preempt)
 573 {
 574         struct btrfs_trans_handle *trans;
 575         u64 delalloc_bytes;
 576         u64 ordered_bytes;
 577         u64 items;
 578         long time_left;
 579         int loops;
 580
 581         delalloc_bytes = percpu_counter_sum_positive(&fs_info->delalloc_bytes);
 582         ordered_bytes = percpu_counter_sum_positive(&fs_info->ordered_bytes);
 583         if (delalloc_bytes == 0 && ordered_bytes == 0)
 584                 return;
 585
 586         /* Calc the number of the pages we need flush for space reservation */
 587         if (to_reclaim == U64_MAX) {
 588                 items = U64_MAX;
 589         } else {
 590                 /*
 591                  * to_reclaim is set to however much metadata we need to
 592                  * reclaim, but reclaiming that much data doesn't really track
 593                  * exactly.  What we really want to do is reclaim full inode's
 594                  * worth of reservations, however that's not available to us
 595                  * here.  We will take a fraction of the delalloc bytes for our
 596                  * flushing loops and hope for the best.  Delalloc will expand
 597                  * the amount we write to cover an entire dirty extent, which
 598                  * will reclaim the metadata reservation for that range.  If
 599                  * it's not enough subsequent flush stages will be more
 600                  * aggressive.
 601                  */
 602                 to_reclaim = max(to_reclaim, delalloc_bytes >> 3);
 603                 items = calc_reclaim_items_nr(fs_info, to_reclaim) * 2;
 604         }
 605
 606         trans = current->journal_info;
 607
 608         /*
 609          * If we are doing more ordered than delalloc we need to just wait on
 610          * ordered extents, otherwise we'll waste time trying to flush delalloc
 611          * that likely won't give us the space back we need.
 612          */
 613         if (ordered_bytes > delalloc_bytes && !for_preempt)
 614                 wait_ordered = true;
 615
 616         loops = 0;
 617         while ((delalloc_bytes || ordered_bytes) && loops < 3) {
 618                 u64 temp = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT;
 619                 long nr_pages = min_t(u64, temp, LONG_MAX);
 620                 int async_pages;
 621
 622                 btrfs_start_delalloc_roots(fs_info, nr_pages, true);
 623
 624                 /*
 625                  * We need to make sure any outstanding async pages are now
 626                  * processed before we continue.  This is because things like
 627                  * sync_inode() try to be smart and skip writing if the inode is
 628                  * marked clean.  We don't use filemap_fwrite for flushing
 629                  * because we want to control how many pages we write out at a
 630                  * time, thus this is the only safe way to make sure we've
 631                  * waited for outstanding compressed workers to have started
 632                  * their jobs and thus have ordered extents set up properly.
 633                  *
 634                  * This exists because we do not want to wait for each
 635                  * individual inode to finish its async work, we simply want to
 636                  * start the IO on everybody, and then come back here and wait
 637                  * for all of the async work to catch up.  Once we're done with
 638                  * that we know we'll have ordered extents for everything and we
 639                  * can decide if we wait for that or not.
 640                  *
 641                  * If we choose to replace this in the future, make absolutely
 642                  * sure that the proper waiting is being done in the async case,
 643                  * as there have been bugs in that area before.
 644                  */
 645                 async_pages = atomic_read(&fs_info->async_delalloc_pages);
 646                 if (!async_pages)
 647                         goto skip_async;
 648
 649                 /*
 650                  * We don't want to wait forever, if we wrote less pages in this
 651                  * loop than we have outstanding, only wait for that number of
 652                  * pages, otherwise we can wait for all async pages to finish
 653                  * before continuing.
 654                  */
 655                 if (async_pages > nr_pages)
 656                         async_pages -= nr_pages;
 657                 else
 658                         async_pages = 0;
 659                 wait_event(fs_info->async_submit_wait,
 660                            atomic_read(&fs_info->async_delalloc_pages) <=
 661                            async_pages);
 662 skip_async:
 663                 loops++;
 664                 if (wait_ordered && !trans) {
 665                         btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
 666                 } else {
 667                         time_left = schedule_timeout_killable(1);
 668                         if (time_left)
 669                                 break;
 670                 }
 671
 672                 /*
 673                  * If we are for preemption we just want a one-shot of delalloc
 674                  * flushing so we can stop flushing if we decide we don't need
 675                  * to anymore.
 676                  */
 677                 if (for_preempt)
 678                         break;
 679
 680                 spin_lock(&space_info->lock);
 681                 if (list_empty(&space_info->tickets) &&
 682                     list_empty(&space_info->priority_tickets)) {
 683                         spin_unlock(&space_info->lock);
 684                         break;
 685                 }
 686                 spin_unlock(&space_info->lock);
 687
 688                 delalloc_bytes = percpu_counter_sum_positive(
 689                                                 &fs_info->delalloc_bytes);
 690                 ordered_bytes = percpu_counter_sum_positive(
 691                                                 &fs_info->ordered_bytes);
 692         }
 693 }
 694
 695 /*
 696  * Try to flush some data based on policy set by @state. This is only advisory
 697  * and may fail for various reasons. The caller is supposed to examine the
 698  * state of @space_info to detect the outcome.
 699  */
 700 static void flush_space(struct btrfs_fs_info *fs_info,
 701                        struct btrfs_space_info *space_info, u64 num_bytes,
 702                        enum btrfs_flush_state state, bool for_preempt)
 703 {
 704         struct btrfs_root *root = fs_info->tree_root;
 705         struct btrfs_trans_handle *trans;
 706         int nr;
 707         int ret = 0;
 708
 709         switch (state) {
 710         case FLUSH_DELAYED_ITEMS_NR:
 711         case FLUSH_DELAYED_ITEMS:
 712                 if (state == FLUSH_DELAYED_ITEMS_NR)
 713                         nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
 714                 else
 715                         nr = -1;
 716
 717                 trans = btrfs_join_transaction(root);
 718                 if (IS_ERR(trans)) {
 719                         ret = PTR_ERR(trans);
 720                         break;
 721                 }
 722                 ret = btrfs_run_delayed_items_nr(trans, nr);
 723                 btrfs_end_transaction(trans);
 724                 break;
 725         case FLUSH_DELALLOC:
 726         case FLUSH_DELALLOC_WAIT:
 727         case FLUSH_DELALLOC_FULL:
 728                 if (state == FLUSH_DELALLOC_FULL)
 729                         num_bytes = U64_MAX;
 730                 shrink_delalloc(fs_info, space_info, num_bytes,
 731                                 state != FLUSH_DELALLOC, for_preempt);
 732                 break;
 733         case FLUSH_DELAYED_REFS_NR:
 734         case FLUSH_DELAYED_REFS:
 735                 trans = btrfs_join_transaction(root);
 736                 if (IS_ERR(trans)) {
 737                         ret = PTR_ERR(trans);
 738                         break;
 739                 }
 740                 if (state == FLUSH_DELAYED_REFS_NR)
 741                         nr = calc_reclaim_items_nr(fs_info, num_bytes);
 742                 else
 743                         nr = 0;
 744                 btrfs_run_delayed_refs(trans, nr);
 745                 btrfs_end_transaction(trans);
 746                 break;
 747         case ALLOC_CHUNK:
 748         case ALLOC_CHUNK_FORCE:
 749                 /*
 750                  * For metadata space on zoned filesystem, reaching here means we
 751                  * don't have enough space left in active_total_bytes. Try to
 752                  * activate a block group first, because we may have inactive
 753                  * block group already allocated.
 754                  */
 755                 ret = btrfs_zoned_activate_one_bg(fs_info, space_info, false);
 756                 if (ret < 0)
 757                         break;
 758                 else if (ret == 1)
 759                         break;
 760
 761                 trans = btrfs_join_transaction(root);
 762                 if (IS_ERR(trans)) {
 763                         ret = PTR_ERR(trans);
 764                         break;
 765                 }
 766                 ret = btrfs_chunk_alloc(trans,
 767                                 btrfs_get_alloc_profile(fs_info, space_info->flags),
 768                                 (state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE :
 769                                         CHUNK_ALLOC_FORCE);
 770                 btrfs_end_transaction(trans);
 771
 772                 /*
 773                  * For metadata space on zoned filesystem, allocating a new chunk
 774                  * is not enough. We still need to activate the block * group.
 775                  * Active the newly allocated block group by (maybe) finishing
 776                  * a block group.
 777                  */
 778                 if (ret == 1) {
 779                         ret = btrfs_zoned_activate_one_bg(fs_info, space_info, true);
 780                         /*
 781                          * Revert to the original ret regardless we could finish
 782                          * one block group or not.
 783                          */
 784                         if (ret >= 0)
 785                                 ret = 1;
 786                 }
 787
 788                 if (ret > 0 || ret == -ENOSPC)
 789                         ret = 0;
 790                 break;
 791         case RUN_DELAYED_IPUTS:
 792                 /*
 793                  * If we have pending delayed iputs then we could free up a
 794                  * bunch of pinned space, so make sure we run the iputs before
 795                  * we do our pinned bytes check below.
 796                  */
 797                 btrfs_run_delayed_iputs(fs_info);
 798                 btrfs_wait_on_delayed_iputs(fs_info);
 799                 break;
 800         case COMMIT_TRANS:
 801                 ASSERT(current->journal_info == NULL);
 802                 trans = btrfs_join_transaction(root);
 803                 if (IS_ERR(trans)) {
 804                         ret = PTR_ERR(trans);
 805                         break;
 806                 }
 807                 ret = btrfs_commit_transaction(trans);
 808                 break;
 809         default:
 810                 ret = -ENOSPC;
 811                 break;
 812         }
 813
 814         trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state,
 815                                 ret, for_preempt);
 816         return;
 817 }
 818
 819 static inline u64
 820 btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
 821                                  struct btrfs_space_info *space_info)
 822 {
 823         u64 used;
 824         u64 avail;
 825         u64 total;
 826         u64 to_reclaim = space_info->reclaim_size;
 827
 828         lockdep_assert_held(&space_info->lock);
 829
 830         avail = calc_available_free_space(fs_info, space_info,
 831                                           BTRFS_RESERVE_FLUSH_ALL);
 832         used = btrfs_space_info_used(space_info, true);
 833
 834         /*
 835          * We may be flushing because suddenly we have less space than we had
 836          * before, and now we're well over-committed based on our current free
 837          * space.  If that's the case add in our overage so we make sure to put
 838          * appropriate pressure on the flushing state machine.
 839          */
 840         total = writable_total_bytes(fs_info, space_info);
 841         if (total + avail < used)
 842                 to_reclaim += used - (total + avail);
 843
 844         return to_reclaim;
 845 }
 846
 847 static bool need_preemptive_reclaim(struct btrfs_fs_info *fs_info,
 848                                     struct btrfs_space_info *space_info)
 849 {
 850         const u64 global_rsv_size = btrfs_block_rsv_reserved(&fs_info->global_block_rsv);
 851         u64 ordered, delalloc;
 852         u64 total = writable_total_bytes(fs_info, space_info);
 853         u64 thresh;
 854         u64 used;
 855
 856         thresh = div_factor_fine(total, 90);
 857
 858         lockdep_assert_held(&space_info->lock);
 859
 860         /* If we're just plain full then async reclaim just slows us down. */
 861         if ((space_info->bytes_used + space_info->bytes_reserved +
 862              global_rsv_size) >= thresh)
 863                 return false;
 864
 865         used = space_info->bytes_may_use + space_info->bytes_pinned;
 866
 867         /* The total flushable belongs to the global rsv, don't flush. */
 868         if (global_rsv_size >= used)
 869                 return false;
 870
 871         /*
 872          * 128MiB is 1/4 of the maximum global rsv size.  If we have less than
 873          * that devoted to other reservations then there's no sense in flushing,
 874          * we don't have a lot of things that need flushing.
 875          */
 876         if (used - global_rsv_size <= SZ_128M)
 877                 return false;
 878
 879         /*
 880          * We have tickets queued, bail so we don't compete with the async
 881          * flushers.
 882          */
 883         if (space_info->reclaim_size)
 884                 return false;
 885
 886         /*
 887          * If we have over half of the free space occupied by reservations or
 888          * pinned then we want to start flushing.
 889          *
 890          * We do not do the traditional thing here, which is to say
 891          *
 892          *   if (used >= ((total_bytes + avail) / 2))
 893          *     return 1;
 894          *
 895          * because this doesn't quite work how we want.  If we had more than 50%
 896          * of the space_info used by bytes_used and we had 0 available we'd just
 897          * constantly run the background flusher.  Instead we want it to kick in
 898          * if our reclaimable space exceeds our clamped free space.
 899          *
 900          * Our clamping range is 2^1 -> 2^8.  Practically speaking that means
 901          * the following:
 902          *
 903          * Amount of RAM        Minimum threshold       Maximum threshold
 904          *
 905          *        256GiB                     1GiB                  128GiB
 906          *        128GiB                   512MiB                   64GiB
 907          *         64GiB                   256MiB                   32GiB
 908          *         32GiB                   128MiB                   16GiB
 909          *         16GiB                    64MiB                    8GiB
 910          *
 911          * These are the range our thresholds will fall in, corresponding to how
 912          * much delalloc we need for the background flusher to kick in.
 913          */
 914
 915         thresh = calc_available_free_space(fs_info, space_info,
 916                                            BTRFS_RESERVE_FLUSH_ALL);
 917         used = space_info->bytes_used + space_info->bytes_reserved +
 918                space_info->bytes_readonly + global_rsv_size;
 919         if (used < total)
 920                 thresh += total - used;
 921         thresh >>= space_info->clamp;
 922
 923         used = space_info->bytes_pinned;
 924
 925         /*
 926          * If we have more ordered bytes than delalloc bytes then we're either
 927          * doing a lot of DIO, or we simply don't have a lot of delalloc waiting
 928          * around.  Preemptive flushing is only useful in that it can free up
 929          * space before tickets need to wait for things to finish.  In the case
 930          * of ordered extents, preemptively waiting on ordered extents gets us
 931          * nothing, if our reservations are tied up in ordered extents we'll
 932          * simply have to slow down writers by forcing them to wait on ordered
 933          * extents.
 934          *
 935          * In the case that ordered is larger than delalloc, only include the
 936          * block reserves that we would actually be able to directly reclaim
 937          * from.  In this case if we're heavy on metadata operations this will
 938          * clearly be heavy enough to warrant preemptive flushing.  In the case
 939          * of heavy DIO or ordered reservations, preemptive flushing will just
 940          * waste time and cause us to slow down.
 941          *
 942          * We want to make sure we truly are maxed out on ordered however, so
 943          * cut ordered in half, and if it's still higher than delalloc then we
 944          * can keep flushing.  This is to avoid the case where we start
 945          * flushing, and now delalloc == ordered and we stop preemptively
 946          * flushing when we could still have several gigs of delalloc to flush.
 947          */
 948         ordered = percpu_counter_read_positive(&fs_info->ordered_bytes) >> 1;
 949         delalloc = percpu_counter_read_positive(&fs_info->delalloc_bytes);
 950         if (ordered >= delalloc)
 951                 used += btrfs_block_rsv_reserved(&fs_info->delayed_refs_rsv) +
 952                         btrfs_block_rsv_reserved(&fs_info->delayed_block_rsv);
 953         else
 954                 used += space_info->bytes_may_use - global_rsv_size;
 955
 956         return (used >= thresh && !btrfs_fs_closing(fs_info) &&
 957                 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
 958 }
 959
 960 static bool steal_from_global_rsv(struct btrfs_fs_info *fs_info,
 961                                   struct btrfs_space_info *space_info,
 962                                   struct reserve_ticket *ticket)
 963 {
 964         struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
 965         u64 min_bytes;
 966
 967         if (!ticket->steal)
 968                 return false;
 969
 970         if (global_rsv->space_info != space_info)
 971                 return false;
 972
 973         spin_lock(&global_rsv->lock);
 974         min_bytes = div_factor(global_rsv->size, 1);
 975         if (global_rsv->reserved < min_bytes + ticket->bytes) {
 976                 spin_unlock(&global_rsv->lock);
 977                 return false;
 978         }
 979         global_rsv->reserved -= ticket->bytes;
 980         remove_ticket(space_info, ticket);
 981         ticket->bytes = 0;
 982         wake_up(&ticket->wait);
 983         space_info->tickets_id++;
 984         if (global_rsv->reserved < global_rsv->size)
 985                 global_rsv->full = 0;
 986         spin_unlock(&global_rsv->lock);
 987
 988         return true;
 989 }
 990
 991 /*
 992  * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets
 993  * @fs_info - fs_info for this fs
 994  * @space_info - the space info we were flushing
 995  *
 996  * We call this when we've exhausted our flushing ability and haven't made
 997  * progress in satisfying tickets.  The reservation code handles tickets in
 998  * order, so if there is a large ticket first and then smaller ones we could
 999  * very well satisfy the smaller tickets.  This will attempt to wake up any
1000  * tickets in the list to catch this case.
1001  *
1002  * This function returns true if it was able to make progress by clearing out
1003  * other tickets, or if it stumbles across a ticket that was smaller than the
1004  * first ticket.
1005  */
1006 static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info,
1007                                    struct btrfs_space_info *space_info)
1008 {
1009         struct reserve_ticket *ticket;
1010         u64 tickets_id = space_info->tickets_id;
1011         const bool aborted = BTRFS_FS_ERROR(fs_info);
1012
1013         trace_btrfs_fail_all_tickets(fs_info, space_info);
1014
1015         if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
1016                 btrfs_info(fs_info, "cannot satisfy tickets, dumping space info");
1017                 __btrfs_dump_space_info(fs_info, space_info);
1018         }
1019
1020         while (!list_empty(&space_info->tickets) &&
1021                tickets_id == space_info->tickets_id) {
1022                 ticket = list_first_entry(&space_info->tickets,
1023                                           struct reserve_ticket, list);
1024
1025                 if (!aborted && steal_from_global_rsv(fs_info, space_info, ticket))
1026                         return true;
1027
1028                 if (!aborted && btrfs_test_opt(fs_info, ENOSPC_DEBUG))
1029                         btrfs_info(fs_info, "failing ticket with %llu bytes",
1030                                    ticket->bytes);
1031
1032                 remove_ticket(space_info, ticket);
1033                 if (aborted)
1034                         ticket->error = -EIO;
1035                 else
1036                         ticket->error = -ENOSPC;
1037                 wake_up(&ticket->wait);
1038
1039                 /*
1040                  * We're just throwing tickets away, so more flushing may not
1041                  * trip over btrfs_try_granting_tickets, so we need to call it
1042                  * here to see if we can make progress with the next ticket in
1043                  * the list.
1044                  */
1045                 if (!aborted)
1046                         btrfs_try_granting_tickets(fs_info, space_info);
1047         }
1048         return (tickets_id != space_info->tickets_id);
1049 }
1050
1051 /*
1052  * This is for normal flushers, we can wait all goddamned day if we want to.  We
1053  * will loop and continuously try to flush as long as we are making progress.
1054  * We count progress as clearing off tickets each time we have to loop.
1055  */
1056 static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
1057 {
1058         struct btrfs_fs_info *fs_info;
1059         struct btrfs_space_info *space_info;
1060         u64 to_reclaim;
1061         enum btrfs_flush_state flush_state;
1062         int commit_cycles = 0;
1063         u64 last_tickets_id;
1064
1065         fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
1066         space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
1067
1068         spin_lock(&space_info->lock);
1069         to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info);
1070         if (!to_reclaim) {
1071                 space_info->flush = 0;
1072                 spin_unlock(&space_info->lock);
1073                 return;
1074         }
1075         last_tickets_id = space_info->tickets_id;
1076         spin_unlock(&space_info->lock);
1077
1078         flush_state = FLUSH_DELAYED_ITEMS_NR;
1079         do {
1080                 flush_space(fs_info, space_info, to_reclaim, flush_state, false);
1081                 spin_lock(&space_info->lock);
1082                 if (list_empty(&space_info->tickets)) {
1083                         space_info->flush = 0;
1084                         spin_unlock(&space_info->lock);
1085                         return;
1086                 }
1087                 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info,
1088                                                               space_info);
1089                 if (last_tickets_id == space_info->tickets_id) {
1090                         flush_state++;
1091                 } else {
1092                         last_tickets_id = space_info->tickets_id;
1093                         flush_state = FLUSH_DELAYED_ITEMS_NR;
1094                         if (commit_cycles)
1095                                 commit_cycles--;
1096                 }
1097
1098                 /*
1099                  * We do not want to empty the system of delalloc unless we're
1100                  * under heavy pressure, so allow one trip through the flushing
1101                  * logic before we start doing a FLUSH_DELALLOC_FULL.
1102                  */
1103                 if (flush_state == FLUSH_DELALLOC_FULL && !commit_cycles)
1104                         flush_state++;
1105
1106                 /*
1107                  * We don't want to force a chunk allocation until we've tried
1108                  * pretty hard to reclaim space.  Think of the case where we
1109                  * freed up a bunch of space and so have a lot of pinned space
1110                  * to reclaim.  We would rather use that than possibly create a
1111                  * underutilized metadata chunk.  So if this is our first run
1112                  * through the flushing state machine skip ALLOC_CHUNK_FORCE and
1113                  * commit the transaction.  If nothing has changed the next go
1114                  * around then we can force a chunk allocation.
1115                  */
1116                 if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles)
1117                         flush_state++;
1118
1119                 if (flush_state > COMMIT_TRANS) {
1120                         commit_cycles++;
1121                         if (commit_cycles > 2) {
1122                                 if (maybe_fail_all_tickets(fs_info, space_info)) {
1123                                         flush_state = FLUSH_DELAYED_ITEMS_NR;
1124                                         commit_cycles--;
1125                                 } else {
1126                                         space_info->flush = 0;
1127                                 }
1128                         } else {
1129                                 flush_state = FLUSH_DELAYED_ITEMS_NR;
1130                         }
1131                 }
1132                 spin_unlock(&space_info->lock);
1133         } while (flush_state <= COMMIT_TRANS);
1134 }
1135
1136 /*
1137  * This handles pre-flushing of metadata space before we get to the point that
1138  * we need to start blocking threads on tickets.  The logic here is different
1139  * from the other flush paths because it doesn't rely on tickets to tell us how
1140  * much we need to flush, instead it attempts to keep us below the 80% full
1141  * watermark of space by flushing whichever reservation pool is currently the
1142  * largest.
1143  */
1144 static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work)
1145 {
1146         struct btrfs_fs_info *fs_info;
1147         struct btrfs_space_info *space_info;
1148         struct btrfs_block_rsv *delayed_block_rsv;
1149         struct btrfs_block_rsv *delayed_refs_rsv;
1150         struct btrfs_block_rsv *global_rsv;
1151         struct btrfs_block_rsv *trans_rsv;
1152         int loops = 0;
1153
1154         fs_info = container_of(work, struct btrfs_fs_info,
1155                                preempt_reclaim_work);
1156         space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
1157         delayed_block_rsv = &fs_info->delayed_block_rsv;
1158         delayed_refs_rsv = &fs_info->delayed_refs_rsv;
1159         global_rsv = &fs_info->global_block_rsv;
1160         trans_rsv = &fs_info->trans_block_rsv;
1161
1162         spin_lock(&space_info->lock);
1163         while (need_preemptive_reclaim(fs_info, space_info)) {
1164                 enum btrfs_flush_state flush;
1165                 u64 delalloc_size = 0;
1166                 u64 to_reclaim, block_rsv_size;
1167                 const u64 global_rsv_size = btrfs_block_rsv_reserved(global_rsv);
1168
1169                 loops++;
1170
1171                 /*
1172                  * We don't have a precise counter for the metadata being
1173                  * reserved for delalloc, so we'll approximate it by subtracting
1174                  * out the block rsv's space from the bytes_may_use.  If that
1175                  * amount is higher than the individual reserves, then we can
1176                  * assume it's tied up in delalloc reservations.
1177                  */
1178                 block_rsv_size = global_rsv_size +
1179                         btrfs_block_rsv_reserved(delayed_block_rsv) +
1180                         btrfs_block_rsv_reserved(delayed_refs_rsv) +
1181                         btrfs_block_rsv_reserved(trans_rsv);
1182                 if (block_rsv_size < space_info->bytes_may_use)
1183                         delalloc_size = space_info->bytes_may_use - block_rsv_size;
1184
1185                 /*
1186                  * We don't want to include the global_rsv in our calculation,
1187                  * because that's space we can't touch.  Subtract it from the
1188                  * block_rsv_size for the next checks.
1189                  */
1190                 block_rsv_size -= global_rsv_size;
1191
1192                 /*
1193                  * We really want to avoid flushing delalloc too much, as it
1194                  * could result in poor allocation patterns, so only flush it if
1195                  * it's larger than the rest of the pools combined.
1196                  */
1197                 if (delalloc_size > block_rsv_size) {
1198                         to_reclaim = delalloc_size;
1199                         flush = FLUSH_DELALLOC;
1200                 } else if (space_info->bytes_pinned >
1201                            (btrfs_block_rsv_reserved(delayed_block_rsv) +
1202                             btrfs_block_rsv_reserved(delayed_refs_rsv))) {
1203                         to_reclaim = space_info->bytes_pinned;
1204                         flush = COMMIT_TRANS;
1205                 } else if (btrfs_block_rsv_reserved(delayed_block_rsv) >
1206                            btrfs_block_rsv_reserved(delayed_refs_rsv)) {
1207                         to_reclaim = btrfs_block_rsv_reserved(delayed_block_rsv);
1208                         flush = FLUSH_DELAYED_ITEMS_NR;
1209                 } else {
1210                         to_reclaim = btrfs_block_rsv_reserved(delayed_refs_rsv);
1211                         flush = FLUSH_DELAYED_REFS_NR;
1212                 }
1213
1214                 spin_unlock(&space_info->lock);
1215
1216                 /*
1217                  * We don't want to reclaim everything, just a portion, so scale
1218                  * down the to_reclaim by 1/4.  If it takes us down to 0,
1219                  * reclaim 1 items worth.
1220                  */
1221                 to_reclaim >>= 2;
1222                 if (!to_reclaim)
1223                         to_reclaim = btrfs_calc_insert_metadata_size(fs_info, 1);
1224                 flush_space(fs_info, space_info, to_reclaim, flush, true);
1225                 cond_resched();
1226                 spin_lock(&space_info->lock);
1227         }
1228
1229         /* We only went through once, back off our clamping. */
1230         if (loops == 1 && !space_info->reclaim_size)
1231                 space_info->clamp = max(1, space_info->clamp - 1);
1232         trace_btrfs_done_preemptive_reclaim(fs_info, space_info);
1233         spin_unlock(&space_info->lock);
1234 }
1235
1236 /*
1237  * FLUSH_DELALLOC_WAIT:
1238  *   Space is freed from flushing delalloc in one of two ways.
1239  *
1240  *   1) compression is on and we allocate less space than we reserved
1241  *   2) we are overwriting existing space
1242  *
1243  *   For #1 that extra space is reclaimed as soon as the delalloc pages are
1244  *   COWed, by way of btrfs_add_reserved_bytes() which adds the actual extent
1245  *   length to ->bytes_reserved, and subtracts the reserved space from
1246  *   ->bytes_may_use.
1247  *
1248  *   For #2 this is trickier.  Once the ordered extent runs we will drop the
1249  *   extent in the range we are overwriting, which creates a delayed ref for
1250  *   that freed extent.  This however is not reclaimed until the transaction
1251  *   commits, thus the next stages.
1252  *
1253  * RUN_DELAYED_IPUTS
1254  *   If we are freeing inodes, we want to make sure all delayed iputs have
1255  *   completed, because they could have been on an inode with i_nlink == 0, and
1256  *   thus have been truncated and freed up space.  But again this space is not
1257  *   immediately re-usable, it comes in the form of a delayed ref, which must be
1258  *   run and then the transaction must be committed.
1259  *
1260  * COMMIT_TRANS
1261  *   This is where we reclaim all of the pinned space generated by running the
1262  *   iputs
1263  *
1264  * ALLOC_CHUNK_FORCE
1265  *   For data we start with alloc chunk force, however we could have been full
1266  *   before, and then the transaction commit could have freed new block groups,
1267  *   so if we now have space to allocate do the force chunk allocation.
1268  */
1269 static const enum btrfs_flush_state data_flush_states[] = {
1270         FLUSH_DELALLOC_FULL,
1271         RUN_DELAYED_IPUTS,
1272         COMMIT_TRANS,
1273         ALLOC_CHUNK_FORCE,
1274 };
1275
1276 static void btrfs_async_reclaim_data_space(struct work_struct *work)
1277 {
1278         struct btrfs_fs_info *fs_info;
1279         struct btrfs_space_info *space_info;
1280         u64 last_tickets_id;
1281         enum btrfs_flush_state flush_state = 0;
1282
1283         fs_info = container_of(work, struct btrfs_fs_info, async_data_reclaim_work);
1284         space_info = fs_info->data_sinfo;
1285
1286         spin_lock(&space_info->lock);
1287         if (list_empty(&space_info->tickets)) {
1288                 space_info->flush = 0;
1289                 spin_unlock(&space_info->lock);
1290                 return;
1291         }
1292         last_tickets_id = space_info->tickets_id;
1293         spin_unlock(&space_info->lock);
1294
1295         while (!space_info->full) {
1296                 flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE, false);
1297                 spin_lock(&space_info->lock);
1298                 if (list_empty(&space_info->tickets)) {
1299                         space_info->flush = 0;
1300                         spin_unlock(&space_info->lock);
1301                         return;
1302                 }
1303
1304                 /* Something happened, fail everything and bail. */
1305                 if (BTRFS_FS_ERROR(fs_info))
1306                         goto aborted_fs;
1307                 last_tickets_id = space_info->tickets_id;
1308                 spin_unlock(&space_info->lock);
1309         }
1310
1311         while (flush_state < ARRAY_SIZE(data_flush_states)) {
1312                 flush_space(fs_info, space_info, U64_MAX,
1313                             data_flush_states[flush_state], false);
1314                 spin_lock(&space_info->lock);
1315                 if (list_empty(&space_info->tickets)) {
1316                         space_info->flush = 0;
1317                         spin_unlock(&space_info->lock);
1318                         return;
1319                 }
1320
1321                 if (last_tickets_id == space_info->tickets_id) {
1322                         flush_state++;
1323                 } else {
1324                         last_tickets_id = space_info->tickets_id;
1325                         flush_state = 0;
1326                 }
1327
1328                 if (flush_state >= ARRAY_SIZE(data_flush_states)) {
1329                         if (space_info->full) {
1330                                 if (maybe_fail_all_tickets(fs_info, space_info))
1331                                         flush_state = 0;
1332                                 else
1333                                         space_info->flush = 0;
1334                         } else {
1335                                 flush_state = 0;
1336                         }
1337
1338                         /* Something happened, fail everything and bail. */
1339                         if (BTRFS_FS_ERROR(fs_info))
1340                                 goto aborted_fs;
1341
1342                 }
1343                 spin_unlock(&space_info->lock);
1344         }
1345         return;
1346
1347 aborted_fs:
1348         maybe_fail_all_tickets(fs_info, space_info);
1349         space_info->flush = 0;
1350         spin_unlock(&space_info->lock);
1351 }
1352
1353 void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info)
1354 {
1355         INIT_WORK(&fs_info->async_reclaim_work, btrfs_async_reclaim_metadata_space);
1356         INIT_WORK(&fs_info->async_data_reclaim_work, btrfs_async_reclaim_data_space);
1357         INIT_WORK(&fs_info->preempt_reclaim_work,
1358                   btrfs_preempt_reclaim_metadata_space);
1359 }
1360
1361 static const enum btrfs_flush_state priority_flush_states[] = {
1362         FLUSH_DELAYED_ITEMS_NR,
1363         FLUSH_DELAYED_ITEMS,
1364         ALLOC_CHUNK,
1365 };
1366
1367 static const enum btrfs_flush_state evict_flush_states[] = {
1368         FLUSH_DELAYED_ITEMS_NR,
1369         FLUSH_DELAYED_ITEMS,
1370         FLUSH_DELAYED_REFS_NR,
1371         FLUSH_DELAYED_REFS,
1372         FLUSH_DELALLOC,
1373         FLUSH_DELALLOC_WAIT,
1374         FLUSH_DELALLOC_FULL,
1375         ALLOC_CHUNK,
1376         COMMIT_TRANS,
1377 };
1378
1379 static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
1380                                 struct btrfs_space_info *space_info,
1381                                 struct reserve_ticket *ticket,
1382                                 const enum btrfs_flush_state *states,
1383                                 int states_nr)
1384 {
1385         u64 to_reclaim;
1386         int flush_state = 0;
1387
1388         spin_lock(&space_info->lock);
1389         to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info);
1390         /*
1391          * This is the priority reclaim path, so to_reclaim could be >0 still
1392          * because we may have only satisfied the priority tickets and still
1393          * left non priority tickets on the list.  We would then have
1394          * to_reclaim but ->bytes == 0.
1395          */
1396         if (ticket->bytes == 0) {
1397                 spin_unlock(&space_info->lock);
1398                 return;
1399         }
1400
1401         while (flush_state < states_nr) {
1402                 spin_unlock(&space_info->lock);
1403                 flush_space(fs_info, space_info, to_reclaim, states[flush_state],
1404                             false);
1405                 flush_state++;
1406                 spin_lock(&space_info->lock);
1407                 if (ticket->bytes == 0) {
1408                         spin_unlock(&space_info->lock);
1409                         return;
1410                 }
1411         }
1412
1413         /* Attempt to steal from the global rsv if we can. */
1414         if (!steal_from_global_rsv(fs_info, space_info, ticket)) {
1415                 ticket->error = -ENOSPC;
1416                 remove_ticket(space_info, ticket);
1417         }
1418
1419         /*
1420          * We must run try_granting_tickets here because we could be a large
1421          * ticket in front of a smaller ticket that can now be satisfied with
1422          * the available space.
1423          */
1424         btrfs_try_granting_tickets(fs_info, space_info);
1425         spin_unlock(&space_info->lock);
1426 }
1427
1428 static void priority_reclaim_data_space(struct btrfs_fs_info *fs_info,
1429                                         struct btrfs_space_info *space_info,
1430                                         struct reserve_ticket *ticket)
1431 {
1432         spin_lock(&space_info->lock);
1433
1434         /* We could have been granted before we got here. */
1435         if (ticket->bytes == 0) {
1436                 spin_unlock(&space_info->lock);
1437                 return;
1438         }
1439
1440         while (!space_info->full) {
1441                 spin_unlock(&space_info->lock);
1442                 flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE, false);
1443                 spin_lock(&space_info->lock);
1444                 if (ticket->bytes == 0) {
1445                         spin_unlock(&space_info->lock);
1446                         return;
1447                 }
1448         }
1449
1450         ticket->error = -ENOSPC;
1451         remove_ticket(space_info, ticket);
1452         btrfs_try_granting_tickets(fs_info, space_info);
1453         spin_unlock(&space_info->lock);
1454 }
1455
1456 static void wait_reserve_ticket(struct btrfs_fs_info *fs_info,
1457                                 struct btrfs_space_info *space_info,
1458                                 struct reserve_ticket *ticket)
1459
1460 {
1461         DEFINE_WAIT(wait);
1462         int ret = 0;
1463
1464         spin_lock(&space_info->lock);
1465         while (ticket->bytes > 0 && ticket->error == 0) {
1466                 ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
1467                 if (ret) {
1468                         /*
1469                          * Delete us from the list. After we unlock the space
1470                          * info, we don't want the async reclaim job to reserve
1471                          * space for this ticket. If that would happen, then the
1472                          * ticket's task would not known that space was reserved
1473                          * despite getting an error, resulting in a space leak
1474                          * (bytes_may_use counter of our space_info).
1475                          */
1476                         remove_ticket(space_info, ticket);
1477                         ticket->error = -EINTR;
1478                         break;
1479                 }
1480                 spin_unlock(&space_info->lock);
1481
1482                 schedule();
1483
1484                 finish_wait(&ticket->wait, &wait);
1485                 spin_lock(&space_info->lock);
1486         }
1487         spin_unlock(&space_info->lock);
1488 }
1489
1490 /**
1491  * Do the appropriate flushing and waiting for a ticket
1492  *
1493  * @fs_info:    the filesystem
1494  * @space_info: space info for the reservation
1495  * @ticket:     ticket for the reservation
1496  * @start_ns:   timestamp when the reservation started
1497  * @orig_bytes: amount of bytes originally reserved
1498  * @flush:      how much we can flush
1499  *
1500  * This does the work of figuring out how to flush for the ticket, waiting for
1501  * the reservation, and returning the appropriate error if there is one.
1502  */
1503 static int handle_reserve_ticket(struct btrfs_fs_info *fs_info,
1504                                  struct btrfs_space_info *space_info,
1505                                  struct reserve_ticket *ticket,
1506                                  u64 start_ns, u64 orig_bytes,
1507                                  enum btrfs_reserve_flush_enum flush)
1508 {
1509         int ret;
1510
1511         switch (flush) {
1512         case BTRFS_RESERVE_FLUSH_DATA:
1513         case BTRFS_RESERVE_FLUSH_ALL:
1514         case BTRFS_RESERVE_FLUSH_ALL_STEAL:
1515                 wait_reserve_ticket(fs_info, space_info, ticket);
1516                 break;
1517         case BTRFS_RESERVE_FLUSH_LIMIT:
1518                 priority_reclaim_metadata_space(fs_info, space_info, ticket,
1519                                                 priority_flush_states,
1520                                                 ARRAY_SIZE(priority_flush_states));
1521                 break;
1522         case BTRFS_RESERVE_FLUSH_EVICT:
1523                 priority_reclaim_metadata_space(fs_info, space_info, ticket,
1524                                                 evict_flush_states,
1525                                                 ARRAY_SIZE(evict_flush_states));
1526                 break;
1527         case BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE:
1528                 priority_reclaim_data_space(fs_info, space_info, ticket);
1529                 break;
1530         default:
1531                 ASSERT(0);
1532                 break;
1533         }
1534
1535         ret = ticket->error;
1536         ASSERT(list_empty(&ticket->list));
1537         /*
1538          * Check that we can't have an error set if the reservation succeeded,
1539          * as that would confuse tasks and lead them to error out without
1540          * releasing reserved space (if an error happens the expectation is that
1541          * space wasn't reserved at all).
1542          */
1543         ASSERT(!(ticket->bytes == 0 && ticket->error));
1544         trace_btrfs_reserve_ticket(fs_info, space_info->flags, orig_bytes,
1545                                    start_ns, flush, ticket->error);
1546         return ret;
1547 }
1548
1549 /*
1550  * This returns true if this flush state will go through the ordinary flushing
1551  * code.
1552  */
1553 static inline bool is_normal_flushing(enum btrfs_reserve_flush_enum flush)
1554 {
1555         return  (flush == BTRFS_RESERVE_FLUSH_ALL) ||
1556                 (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL);
1557 }
1558
1559 static inline void maybe_clamp_preempt(struct btrfs_fs_info *fs_info,
1560                                        struct btrfs_space_info *space_info)
1561 {
1562         u64 ordered = percpu_counter_sum_positive(&fs_info->ordered_bytes);
1563         u64 delalloc = percpu_counter_sum_positive(&fs_info->delalloc_bytes);
1564
1565         /*
1566          * If we're heavy on ordered operations then clamping won't help us.  We
1567          * need to clamp specifically to keep up with dirty'ing buffered
1568          * writers, because there's not a 1:1 correlation of writing delalloc
1569          * and freeing space, like there is with flushing delayed refs or
1570          * delayed nodes.  If we're already more ordered than delalloc then
1571          * we're keeping up, otherwise we aren't and should probably clamp.
1572          */
1573         if (ordered < delalloc)
1574                 space_info->clamp = min(space_info->clamp + 1, 8);
1575 }
1576
1577 static inline bool can_steal(enum btrfs_reserve_flush_enum flush)
1578 {
1579         return (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL ||
1580                 flush == BTRFS_RESERVE_FLUSH_EVICT);
1581 }
1582
1583 /**
1584  * Try to reserve bytes from the block_rsv's space
1585  *
1586  * @fs_info:    the filesystem
1587  * @space_info: space info we want to allocate from
1588  * @orig_bytes: number of bytes we want
1589  * @flush:      whether or not we can flush to make our reservation
1590  *
1591  * This will reserve orig_bytes number of bytes from the space info associated
1592  * with the block_rsv.  If there is not enough space it will make an attempt to
1593  * flush out space to make room.  It will do this by flushing delalloc if
1594  * possible or committing the transaction.  If flush is 0 then no attempts to
1595  * regain reservations will be made and this will fail if there is not enough
1596  * space already.
1597  */
1598 static int __reserve_bytes(struct btrfs_fs_info *fs_info,
1599                            struct btrfs_space_info *space_info, u64 orig_bytes,
1600                            enum btrfs_reserve_flush_enum flush)
1601 {
1602         struct work_struct *async_work;
1603         struct reserve_ticket ticket;
1604         u64 start_ns = 0;
1605         u64 used;
1606         int ret = 0;
1607         bool pending_tickets;
1608
1609         ASSERT(orig_bytes);
1610         ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
1611
1612         if (flush == BTRFS_RESERVE_FLUSH_DATA)
1613                 async_work = &fs_info->async_data_reclaim_work;
1614         else
1615                 async_work = &fs_info->async_reclaim_work;
1616
1617         spin_lock(&space_info->lock);
1618         ret = -ENOSPC;
1619         used = btrfs_space_info_used(space_info, true);
1620
1621         /*
1622          * We don't want NO_FLUSH allocations to jump everybody, they can
1623          * generally handle ENOSPC in a different way, so treat them the same as
1624          * normal flushers when it comes to skipping pending tickets.
1625          */
1626         if (is_normal_flushing(flush) || (flush == BTRFS_RESERVE_NO_FLUSH))
1627                 pending_tickets = !list_empty(&space_info->tickets) ||
1628                         !list_empty(&space_info->priority_tickets);
1629         else
1630                 pending_tickets = !list_empty(&space_info->priority_tickets);
1631
1632         /*
1633          * Carry on if we have enough space (short-circuit) OR call
1634          * can_overcommit() to ensure we can overcommit to continue.
1635          */
1636         if (!pending_tickets &&
1637             ((used + orig_bytes <= writable_total_bytes(fs_info, space_info)) ||
1638              btrfs_can_overcommit(fs_info, space_info, orig_bytes, flush))) {
1639                 btrfs_space_info_update_bytes_may_use(fs_info, space_info,
1640                                                       orig_bytes);
1641                 ret = 0;
1642         }
1643
1644         /*
1645          * If we couldn't make a reservation then setup our reservation ticket
1646          * and kick the async worker if it's not already running.
1647          *
1648          * If we are a priority flusher then we just need to add our ticket to
1649          * the list and we will do our own flushing further down.
1650          */
1651         if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
1652                 ticket.bytes = orig_bytes;
1653                 ticket.error = 0;
1654                 space_info->reclaim_size += ticket.bytes;
1655                 init_waitqueue_head(&ticket.wait);
1656                 ticket.steal = can_steal(flush);
1657                 if (trace_btrfs_reserve_ticket_enabled())
1658                         start_ns = ktime_get_ns();
1659
1660                 if (flush == BTRFS_RESERVE_FLUSH_ALL ||
1661                     flush == BTRFS_RESERVE_FLUSH_ALL_STEAL ||
1662                     flush == BTRFS_RESERVE_FLUSH_DATA) {
1663                         list_add_tail(&ticket.list, &space_info->tickets);
1664                         if (!space_info->flush) {
1665                                 /*
1666                                  * We were forced to add a reserve ticket, so
1667                                  * our preemptive flushing is unable to keep
1668                                  * up.  Clamp down on the threshold for the
1669                                  * preemptive flushing in order to keep up with
1670                                  * the workload.
1671                                  */
1672                                 maybe_clamp_preempt(fs_info, space_info);
1673
1674                                 space_info->flush = 1;
1675                                 trace_btrfs_trigger_flush(fs_info,
1676                                                           space_info->flags,
1677                                                           orig_bytes, flush,
1678                                                           "enospc");
1679                                 queue_work(system_unbound_wq, async_work);
1680                         }
1681                 } else {
1682                         list_add_tail(&ticket.list,
1683                                       &space_info->priority_tickets);
1684                 }
1685         } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
1686                 /*
1687                  * We will do the space reservation dance during log replay,
1688                  * which means we won't have fs_info->fs_root set, so don't do
1689                  * the async reclaim as we will panic.
1690                  */
1691                 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
1692                     !work_busy(&fs_info->preempt_reclaim_work) &&
1693                     need_preemptive_reclaim(fs_info, space_info)) {
1694                         trace_btrfs_trigger_flush(fs_info, space_info->flags,
1695                                                   orig_bytes, flush, "preempt");
1696                         queue_work(system_unbound_wq,
1697                                    &fs_info->preempt_reclaim_work);
1698                 }
1699         }
1700         spin_unlock(&space_info->lock);
1701         if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
1702                 return ret;
1703
1704         return handle_reserve_ticket(fs_info, space_info, &ticket, start_ns,
1705                                      orig_bytes, flush);
1706 }
1707
1708 /**
1709  * Trye to reserve metadata bytes from the block_rsv's space
1710  *
1711  * @fs_info:    the filesystem
1712  * @block_rsv:  block_rsv we're allocating for
1713  * @orig_bytes: number of bytes we want
1714  * @flush:      whether or not we can flush to make our reservation
1715  *
1716  * This will reserve orig_bytes number of bytes from the space info associated
1717  * with the block_rsv.  If there is not enough space it will make an attempt to
1718  * flush out space to make room.  It will do this by flushing delalloc if
1719  * possible or committing the transaction.  If flush is 0 then no attempts to
1720  * regain reservations will be made and this will fail if there is not enough
1721  * space already.
1722  */
1723 int btrfs_reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
1724                                  struct btrfs_block_rsv *block_rsv,
1725                                  u64 orig_bytes,
1726                                  enum btrfs_reserve_flush_enum flush)
1727 {
1728         int ret;
1729
1730         ret = __reserve_bytes(fs_info, block_rsv->space_info, orig_bytes, flush);
1731         if (ret == -ENOSPC) {
1732                 trace_btrfs_space_reservation(fs_info, "space_info:enospc",
1733                                               block_rsv->space_info->flags,
1734                                               orig_bytes, 1);
1735
1736                 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
1737                         btrfs_dump_space_info(fs_info, block_rsv->space_info,
1738                                               orig_bytes, 0);
1739         }
1740         return ret;
1741 }
1742
1743 /**
1744  * Try to reserve data bytes for an allocation
1745  *
1746  * @fs_info: the filesystem
1747  * @bytes:   number of bytes we need
1748  * @flush:   how we are allowed to flush
1749  *
1750  * This will reserve bytes from the data space info.  If there is not enough
1751  * space then we will attempt to flush space as specified by flush.
1752  */
1753 int btrfs_reserve_data_bytes(struct btrfs_fs_info *fs_info, u64 bytes,
1754                              enum btrfs_reserve_flush_enum flush)
1755 {
1756         struct btrfs_space_info *data_sinfo = fs_info->data_sinfo;
1757         int ret;
1758
1759         ASSERT(flush == BTRFS_RESERVE_FLUSH_DATA ||
1760                flush == BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE ||
1761                flush == BTRFS_RESERVE_NO_FLUSH);
1762         ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_DATA);
1763
1764         ret = __reserve_bytes(fs_info, data_sinfo, bytes, flush);
1765         if (ret == -ENOSPC) {
1766                 trace_btrfs_space_reservation(fs_info, "space_info:enospc",
1767                                               data_sinfo->flags, bytes, 1);
1768                 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
1769                         btrfs_dump_space_info(fs_info, data_sinfo, bytes, 0);
1770         }
1771         return ret;
1772 }
1773
1774 /* Dump all the space infos when we abort a transaction due to ENOSPC. */
1775 __cold void btrfs_dump_space_info_for_trans_abort(struct btrfs_fs_info *fs_info)
1776 {
1777         struct btrfs_space_info *space_info;
1778
1779         btrfs_info(fs_info, "dumping space info:");
1780         list_for_each_entry(space_info, &fs_info->space_info, list) {
1781                 spin_lock(&space_info->lock);
1782                 __btrfs_dump_space_info(fs_info, space_info);
1783                 spin_unlock(&space_info->lock);
1784         }
1785         dump_global_block_rsv(fs_info);
1786 }