1 // SPDX-License-Identifier: GPL-2.0
5 #include "space-info.h"
8 #include "free-space-cache.h"
9 #include "ordered-data.h"
10 #include "transaction.h"
11 #include "block-group.h"
13 u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
14 bool may_use_included)
17 return s_info->bytes_used + s_info->bytes_reserved +
18 s_info->bytes_pinned + s_info->bytes_readonly +
19 (may_use_included ? s_info->bytes_may_use : 0);
23 * after adding space to the filesystem, we need to clear the full flags
24 * on all the space infos.
26 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
28 struct list_head *head = &info->space_info;
29 struct btrfs_space_info *found;
32 list_for_each_entry_rcu(found, head, list)
37 static int create_space_info(struct btrfs_fs_info *info, u64 flags)
40 struct btrfs_space_info *space_info;
44 space_info = kzalloc(sizeof(*space_info), GFP_NOFS);
48 ret = percpu_counter_init(&space_info->total_bytes_pinned, 0,
55 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
56 INIT_LIST_HEAD(&space_info->block_groups[i]);
57 init_rwsem(&space_info->groups_sem);
58 spin_lock_init(&space_info->lock);
59 space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
60 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
61 INIT_LIST_HEAD(&space_info->ro_bgs);
62 INIT_LIST_HEAD(&space_info->tickets);
63 INIT_LIST_HEAD(&space_info->priority_tickets);
65 ret = btrfs_sysfs_add_space_info_type(info, space_info);
69 list_add_rcu(&space_info->list, &info->space_info);
70 if (flags & BTRFS_BLOCK_GROUP_DATA)
71 info->data_sinfo = space_info;
76 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
78 struct btrfs_super_block *disk_super;
84 disk_super = fs_info->super_copy;
85 if (!btrfs_super_root(disk_super))
88 features = btrfs_super_incompat_flags(disk_super);
89 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
92 flags = BTRFS_BLOCK_GROUP_SYSTEM;
93 ret = create_space_info(fs_info, flags);
98 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
99 ret = create_space_info(fs_info, flags);
101 flags = BTRFS_BLOCK_GROUP_METADATA;
102 ret = create_space_info(fs_info, flags);
106 flags = BTRFS_BLOCK_GROUP_DATA;
107 ret = create_space_info(fs_info, flags);
113 void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
114 u64 total_bytes, u64 bytes_used,
116 struct btrfs_space_info **space_info)
118 struct btrfs_space_info *found;
121 factor = btrfs_bg_type_to_factor(flags);
123 found = btrfs_find_space_info(info, flags);
125 spin_lock(&found->lock);
126 found->total_bytes += total_bytes;
127 found->disk_total += total_bytes * factor;
128 found->bytes_used += bytes_used;
129 found->disk_used += bytes_used * factor;
130 found->bytes_readonly += bytes_readonly;
133 btrfs_try_granting_tickets(info, found);
134 spin_unlock(&found->lock);
138 struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
141 struct list_head *head = &info->space_info;
142 struct btrfs_space_info *found;
144 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
147 list_for_each_entry_rcu(found, head, list) {
148 if (found->flags & flags) {
157 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
159 return (global->size << 1);
162 static int can_overcommit(struct btrfs_fs_info *fs_info,
163 struct btrfs_space_info *space_info, u64 bytes,
164 enum btrfs_reserve_flush_enum flush,
172 /* Don't overcommit when in mixed mode. */
173 if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
177 profile = btrfs_system_alloc_profile(fs_info);
179 profile = btrfs_metadata_alloc_profile(fs_info);
181 used = btrfs_space_info_used(space_info, true);
182 avail = atomic64_read(&fs_info->free_chunk_space);
185 * If we have dup, raid1 or raid10 then only half of the free
186 * space is actually usable. For raid56, the space info used
187 * doesn't include the parity drive, so we don't have to
190 factor = btrfs_bg_type_to_factor(profile);
191 avail = div_u64(avail, factor);
194 * If we aren't flushing all things, let us overcommit up to
195 * 1/2th of the space. If we can flush, don't let us overcommit
196 * too much, let it overcommit up to 1/8 of the space.
198 if (flush == BTRFS_RESERVE_FLUSH_ALL)
203 if (used + bytes < space_info->total_bytes + avail)
209 * This is for space we already have accounted in space_info->bytes_may_use, so
210 * basically when we're returning space from block_rsv's.
212 void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
213 struct btrfs_space_info *space_info)
215 struct list_head *head;
216 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
218 lockdep_assert_held(&space_info->lock);
220 head = &space_info->priority_tickets;
222 while (!list_empty(head)) {
223 struct reserve_ticket *ticket;
224 u64 used = btrfs_space_info_used(space_info, true);
226 ticket = list_first_entry(head, struct reserve_ticket, list);
228 /* Check and see if our ticket can be satisified now. */
229 if ((used + ticket->bytes <= space_info->total_bytes) ||
230 can_overcommit(fs_info, space_info, ticket->bytes, flush,
232 btrfs_space_info_update_bytes_may_use(fs_info,
235 list_del_init(&ticket->list);
237 space_info->tickets_id++;
238 wake_up(&ticket->wait);
244 if (head == &space_info->priority_tickets) {
245 head = &space_info->tickets;
246 flush = BTRFS_RESERVE_FLUSH_ALL;
251 #define DUMP_BLOCK_RSV(fs_info, rsv_name) \
253 struct btrfs_block_rsv *__rsv = &(fs_info)->rsv_name; \
254 spin_lock(&__rsv->lock); \
255 btrfs_info(fs_info, #rsv_name ": size %llu reserved %llu", \
256 __rsv->size, __rsv->reserved); \
257 spin_unlock(&__rsv->lock); \
260 static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
261 struct btrfs_space_info *info)
263 lockdep_assert_held(&info->lock);
265 btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull",
267 info->total_bytes - btrfs_space_info_used(info, true),
268 info->full ? "" : "not ");
270 "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
271 info->total_bytes, info->bytes_used, info->bytes_pinned,
272 info->bytes_reserved, info->bytes_may_use,
273 info->bytes_readonly);
275 DUMP_BLOCK_RSV(fs_info, global_block_rsv);
276 DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
277 DUMP_BLOCK_RSV(fs_info, chunk_block_rsv);
278 DUMP_BLOCK_RSV(fs_info, delayed_block_rsv);
279 DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv);
283 void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
284 struct btrfs_space_info *info, u64 bytes,
285 int dump_block_groups)
287 struct btrfs_block_group *cache;
290 spin_lock(&info->lock);
291 __btrfs_dump_space_info(fs_info, info);
292 spin_unlock(&info->lock);
294 if (!dump_block_groups)
297 down_read(&info->groups_sem);
299 list_for_each_entry(cache, &info->block_groups[index], list) {
300 spin_lock(&cache->lock);
302 "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
303 cache->start, cache->length, cache->used, cache->pinned,
304 cache->reserved, cache->ro ? "[readonly]" : "");
305 btrfs_dump_free_space(cache, bytes);
306 spin_unlock(&cache->lock);
308 if (++index < BTRFS_NR_RAID_TYPES)
310 up_read(&info->groups_sem);
313 static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info,
314 unsigned long nr_pages, int nr_items)
316 struct super_block *sb = fs_info->sb;
318 if (down_read_trylock(&sb->s_umount)) {
319 writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
320 up_read(&sb->s_umount);
323 * We needn't worry the filesystem going from r/w to r/o though
324 * we don't acquire ->s_umount mutex, because the filesystem
325 * should guarantee the delalloc inodes list be empty after
326 * the filesystem is readonly(all dirty pages are written to
329 btrfs_start_delalloc_roots(fs_info, nr_items);
330 if (!current->journal_info)
331 btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1);
335 static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
341 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
342 nr = div64_u64(to_reclaim, bytes);
348 #define EXTENT_SIZE_PER_ITEM SZ_256K
351 * shrink metadata reservation for delalloc
353 static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim,
354 u64 orig, bool wait_ordered)
356 struct btrfs_space_info *space_info;
357 struct btrfs_trans_handle *trans;
363 unsigned long nr_pages;
366 /* Calc the number of the pages we need flush for space reservation */
367 items = calc_reclaim_items_nr(fs_info, to_reclaim);
368 to_reclaim = items * EXTENT_SIZE_PER_ITEM;
370 trans = (struct btrfs_trans_handle *)current->journal_info;
371 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
373 delalloc_bytes = percpu_counter_sum_positive(
374 &fs_info->delalloc_bytes);
375 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes);
376 if (delalloc_bytes == 0 && dio_bytes == 0) {
380 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
385 * If we are doing more ordered than delalloc we need to just wait on
386 * ordered extents, otherwise we'll waste time trying to flush delalloc
387 * that likely won't give us the space back we need.
389 if (dio_bytes > delalloc_bytes)
393 while ((delalloc_bytes || dio_bytes) && loops < 3) {
394 nr_pages = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT;
397 * Triggers inode writeback for up to nr_pages. This will invoke
398 * ->writepages callback and trigger delalloc filling
399 * (btrfs_run_delalloc_range()).
401 btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items);
404 * We need to wait for the compressed pages to start before
407 async_pages = atomic_read(&fs_info->async_delalloc_pages);
412 * Calculate how many compressed pages we want to be written
413 * before we continue. I.e if there are more async pages than we
414 * require wait_event will wait until nr_pages are written.
416 if (async_pages <= nr_pages)
419 async_pages -= nr_pages;
421 wait_event(fs_info->async_submit_wait,
422 atomic_read(&fs_info->async_delalloc_pages) <=
425 spin_lock(&space_info->lock);
426 if (list_empty(&space_info->tickets) &&
427 list_empty(&space_info->priority_tickets)) {
428 spin_unlock(&space_info->lock);
431 spin_unlock(&space_info->lock);
434 if (wait_ordered && !trans) {
435 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
437 time_left = schedule_timeout_killable(1);
441 delalloc_bytes = percpu_counter_sum_positive(
442 &fs_info->delalloc_bytes);
443 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes);
448 * maybe_commit_transaction - possibly commit the transaction if its ok to
449 * @root - the root we're allocating for
450 * @bytes - the number of bytes we want to reserve
451 * @force - force the commit
453 * This will check to make sure that committing the transaction will actually
454 * get us somewhere and then commit the transaction if it does. Otherwise it
455 * will return -ENOSPC.
457 static int may_commit_transaction(struct btrfs_fs_info *fs_info,
458 struct btrfs_space_info *space_info)
460 struct reserve_ticket *ticket = NULL;
461 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv;
462 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
463 struct btrfs_trans_handle *trans;
465 u64 reclaim_bytes = 0;
466 u64 cur_free_bytes = 0;
468 trans = (struct btrfs_trans_handle *)current->journal_info;
472 spin_lock(&space_info->lock);
473 cur_free_bytes = btrfs_space_info_used(space_info, true);
474 if (cur_free_bytes < space_info->total_bytes)
475 cur_free_bytes = space_info->total_bytes - cur_free_bytes;
479 if (!list_empty(&space_info->priority_tickets))
480 ticket = list_first_entry(&space_info->priority_tickets,
481 struct reserve_ticket, list);
482 else if (!list_empty(&space_info->tickets))
483 ticket = list_first_entry(&space_info->tickets,
484 struct reserve_ticket, list);
485 bytes_needed = (ticket) ? ticket->bytes : 0;
487 if (bytes_needed > cur_free_bytes)
488 bytes_needed -= cur_free_bytes;
491 spin_unlock(&space_info->lock);
496 trans = btrfs_join_transaction(fs_info->extent_root);
498 return PTR_ERR(trans);
501 * See if there is enough pinned space to make this reservation, or if
502 * we have block groups that are going to be freed, allowing us to
503 * possibly do a chunk allocation the next loop through.
505 if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags) ||
506 __percpu_counter_compare(&space_info->total_bytes_pinned,
508 BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0)
512 * See if there is some space in the delayed insertion reservation for
515 if (space_info != delayed_rsv->space_info)
518 spin_lock(&delayed_rsv->lock);
519 reclaim_bytes += delayed_rsv->reserved;
520 spin_unlock(&delayed_rsv->lock);
522 spin_lock(&delayed_refs_rsv->lock);
523 reclaim_bytes += delayed_refs_rsv->reserved;
524 spin_unlock(&delayed_refs_rsv->lock);
525 if (reclaim_bytes >= bytes_needed)
527 bytes_needed -= reclaim_bytes;
529 if (__percpu_counter_compare(&space_info->total_bytes_pinned,
531 BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0)
535 return btrfs_commit_transaction(trans);
537 btrfs_end_transaction(trans);
542 * Try to flush some data based on policy set by @state. This is only advisory
543 * and may fail for various reasons. The caller is supposed to examine the
544 * state of @space_info to detect the outcome.
546 static void flush_space(struct btrfs_fs_info *fs_info,
547 struct btrfs_space_info *space_info, u64 num_bytes,
550 struct btrfs_root *root = fs_info->extent_root;
551 struct btrfs_trans_handle *trans;
556 case FLUSH_DELAYED_ITEMS_NR:
557 case FLUSH_DELAYED_ITEMS:
558 if (state == FLUSH_DELAYED_ITEMS_NR)
559 nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
563 trans = btrfs_join_transaction(root);
565 ret = PTR_ERR(trans);
568 ret = btrfs_run_delayed_items_nr(trans, nr);
569 btrfs_end_transaction(trans);
572 case FLUSH_DELALLOC_WAIT:
573 shrink_delalloc(fs_info, num_bytes * 2, num_bytes,
574 state == FLUSH_DELALLOC_WAIT);
576 case FLUSH_DELAYED_REFS_NR:
577 case FLUSH_DELAYED_REFS:
578 trans = btrfs_join_transaction(root);
580 ret = PTR_ERR(trans);
583 if (state == FLUSH_DELAYED_REFS_NR)
584 nr = calc_reclaim_items_nr(fs_info, num_bytes);
587 btrfs_run_delayed_refs(trans, nr);
588 btrfs_end_transaction(trans);
591 case ALLOC_CHUNK_FORCE:
592 trans = btrfs_join_transaction(root);
594 ret = PTR_ERR(trans);
597 ret = btrfs_chunk_alloc(trans,
598 btrfs_metadata_alloc_profile(fs_info),
599 (state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE :
601 btrfs_end_transaction(trans);
602 if (ret > 0 || ret == -ENOSPC)
605 case RUN_DELAYED_IPUTS:
607 * If we have pending delayed iputs then we could free up a
608 * bunch of pinned space, so make sure we run the iputs before
609 * we do our pinned bytes check below.
611 btrfs_run_delayed_iputs(fs_info);
612 btrfs_wait_on_delayed_iputs(fs_info);
615 ret = may_commit_transaction(fs_info, space_info);
622 trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state,
628 btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
629 struct btrfs_space_info *space_info,
632 struct reserve_ticket *ticket;
637 list_for_each_entry(ticket, &space_info->tickets, list)
638 to_reclaim += ticket->bytes;
639 list_for_each_entry(ticket, &space_info->priority_tickets, list)
640 to_reclaim += ticket->bytes;
644 to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M);
645 if (can_overcommit(fs_info, space_info, to_reclaim,
646 BTRFS_RESERVE_FLUSH_ALL, system_chunk))
649 used = btrfs_space_info_used(space_info, true);
651 if (can_overcommit(fs_info, space_info, SZ_1M,
652 BTRFS_RESERVE_FLUSH_ALL, system_chunk))
653 expected = div_factor_fine(space_info->total_bytes, 95);
655 expected = div_factor_fine(space_info->total_bytes, 90);
658 to_reclaim = used - expected;
661 to_reclaim = min(to_reclaim, space_info->bytes_may_use +
662 space_info->bytes_reserved);
666 static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info,
667 struct btrfs_space_info *space_info,
668 u64 used, bool system_chunk)
670 u64 thresh = div_factor_fine(space_info->total_bytes, 98);
672 /* If we're just plain full then async reclaim just slows us down. */
673 if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh)
676 if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info,
680 return (used >= thresh && !btrfs_fs_closing(fs_info) &&
681 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
685 * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets
686 * @fs_info - fs_info for this fs
687 * @space_info - the space info we were flushing
689 * We call this when we've exhausted our flushing ability and haven't made
690 * progress in satisfying tickets. The reservation code handles tickets in
691 * order, so if there is a large ticket first and then smaller ones we could
692 * very well satisfy the smaller tickets. This will attempt to wake up any
693 * tickets in the list to catch this case.
695 * This function returns true if it was able to make progress by clearing out
696 * other tickets, or if it stumbles across a ticket that was smaller than the
699 static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info,
700 struct btrfs_space_info *space_info)
702 struct reserve_ticket *ticket;
703 u64 tickets_id = space_info->tickets_id;
704 u64 first_ticket_bytes = 0;
706 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
707 btrfs_info(fs_info, "cannot satisfy tickets, dumping space info");
708 __btrfs_dump_space_info(fs_info, space_info);
711 while (!list_empty(&space_info->tickets) &&
712 tickets_id == space_info->tickets_id) {
713 ticket = list_first_entry(&space_info->tickets,
714 struct reserve_ticket, list);
717 * may_commit_transaction will avoid committing the transaction
718 * if it doesn't feel like the space reclaimed by the commit
719 * would result in the ticket succeeding. However if we have a
720 * smaller ticket in the queue it may be small enough to be
721 * satisified by committing the transaction, so if any
722 * subsequent ticket is smaller than the first ticket go ahead
723 * and send us back for another loop through the enospc flushing
726 if (first_ticket_bytes == 0)
727 first_ticket_bytes = ticket->bytes;
728 else if (first_ticket_bytes > ticket->bytes)
731 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
732 btrfs_info(fs_info, "failing ticket with %llu bytes",
735 list_del_init(&ticket->list);
736 ticket->error = -ENOSPC;
737 wake_up(&ticket->wait);
740 * We're just throwing tickets away, so more flushing may not
741 * trip over btrfs_try_granting_tickets, so we need to call it
742 * here to see if we can make progress with the next ticket in
745 btrfs_try_granting_tickets(fs_info, space_info);
747 return (tickets_id != space_info->tickets_id);
751 * This is for normal flushers, we can wait all goddamned day if we want to. We
752 * will loop and continuously try to flush as long as we are making progress.
753 * We count progress as clearing off tickets each time we have to loop.
755 static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
757 struct btrfs_fs_info *fs_info;
758 struct btrfs_space_info *space_info;
761 int commit_cycles = 0;
764 fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
765 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
767 spin_lock(&space_info->lock);
768 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
771 space_info->flush = 0;
772 spin_unlock(&space_info->lock);
775 last_tickets_id = space_info->tickets_id;
776 spin_unlock(&space_info->lock);
778 flush_state = FLUSH_DELAYED_ITEMS_NR;
780 flush_space(fs_info, space_info, to_reclaim, flush_state);
781 spin_lock(&space_info->lock);
782 if (list_empty(&space_info->tickets)) {
783 space_info->flush = 0;
784 spin_unlock(&space_info->lock);
787 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info,
790 if (last_tickets_id == space_info->tickets_id) {
793 last_tickets_id = space_info->tickets_id;
794 flush_state = FLUSH_DELAYED_ITEMS_NR;
800 * We don't want to force a chunk allocation until we've tried
801 * pretty hard to reclaim space. Think of the case where we
802 * freed up a bunch of space and so have a lot of pinned space
803 * to reclaim. We would rather use that than possibly create a
804 * underutilized metadata chunk. So if this is our first run
805 * through the flushing state machine skip ALLOC_CHUNK_FORCE and
806 * commit the transaction. If nothing has changed the next go
807 * around then we can force a chunk allocation.
809 if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles)
812 if (flush_state > COMMIT_TRANS) {
814 if (commit_cycles > 2) {
815 if (maybe_fail_all_tickets(fs_info, space_info)) {
816 flush_state = FLUSH_DELAYED_ITEMS_NR;
819 space_info->flush = 0;
822 flush_state = FLUSH_DELAYED_ITEMS_NR;
825 spin_unlock(&space_info->lock);
826 } while (flush_state <= COMMIT_TRANS);
829 void btrfs_init_async_reclaim_work(struct work_struct *work)
831 INIT_WORK(work, btrfs_async_reclaim_metadata_space);
834 static const enum btrfs_flush_state priority_flush_states[] = {
835 FLUSH_DELAYED_ITEMS_NR,
840 static const enum btrfs_flush_state evict_flush_states[] = {
841 FLUSH_DELAYED_ITEMS_NR,
843 FLUSH_DELAYED_REFS_NR,
851 static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
852 struct btrfs_space_info *space_info,
853 struct reserve_ticket *ticket,
854 const enum btrfs_flush_state *states,
860 spin_lock(&space_info->lock);
861 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
864 spin_unlock(&space_info->lock);
867 spin_unlock(&space_info->lock);
871 flush_space(fs_info, space_info, to_reclaim, states[flush_state]);
873 spin_lock(&space_info->lock);
874 if (ticket->bytes == 0) {
875 spin_unlock(&space_info->lock);
878 spin_unlock(&space_info->lock);
879 } while (flush_state < states_nr);
882 static void wait_reserve_ticket(struct btrfs_fs_info *fs_info,
883 struct btrfs_space_info *space_info,
884 struct reserve_ticket *ticket)
890 spin_lock(&space_info->lock);
891 while (ticket->bytes > 0 && ticket->error == 0) {
892 ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
895 * Delete us from the list. After we unlock the space
896 * info, we don't want the async reclaim job to reserve
897 * space for this ticket. If that would happen, then the
898 * ticket's task would not known that space was reserved
899 * despite getting an error, resulting in a space leak
900 * (bytes_may_use counter of our space_info).
902 list_del_init(&ticket->list);
903 ticket->error = -EINTR;
906 spin_unlock(&space_info->lock);
910 finish_wait(&ticket->wait, &wait);
911 spin_lock(&space_info->lock);
913 spin_unlock(&space_info->lock);
917 * handle_reserve_ticket - do the appropriate flushing and waiting for a ticket
919 * @space_info - the space_info for the reservation
920 * @ticket - the ticket for the reservation
921 * @flush - how much we can flush
923 * This does the work of figuring out how to flush for the ticket, waiting for
924 * the reservation, and returning the appropriate error if there is one.
926 static int handle_reserve_ticket(struct btrfs_fs_info *fs_info,
927 struct btrfs_space_info *space_info,
928 struct reserve_ticket *ticket,
929 enum btrfs_reserve_flush_enum flush)
934 case BTRFS_RESERVE_FLUSH_ALL:
935 wait_reserve_ticket(fs_info, space_info, ticket);
937 case BTRFS_RESERVE_FLUSH_LIMIT:
938 priority_reclaim_metadata_space(fs_info, space_info, ticket,
939 priority_flush_states,
940 ARRAY_SIZE(priority_flush_states));
942 case BTRFS_RESERVE_FLUSH_EVICT:
943 priority_reclaim_metadata_space(fs_info, space_info, ticket,
945 ARRAY_SIZE(evict_flush_states));
952 spin_lock(&space_info->lock);
954 if (ticket->bytes || ticket->error) {
956 * Need to delete here for priority tickets. For regular tickets
957 * either the async reclaim job deletes the ticket from the list
958 * or we delete it ourselves at wait_reserve_ticket().
960 list_del_init(&ticket->list);
964 spin_unlock(&space_info->lock);
965 ASSERT(list_empty(&ticket->list));
967 * Check that we can't have an error set if the reservation succeeded,
968 * as that would confuse tasks and lead them to error out without
969 * releasing reserved space (if an error happens the expectation is that
970 * space wasn't reserved at all).
972 ASSERT(!(ticket->bytes == 0 && ticket->error));
977 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
978 * @root - the root we're allocating for
979 * @space_info - the space info we want to allocate from
980 * @orig_bytes - the number of bytes we want
981 * @flush - whether or not we can flush to make our reservation
983 * This will reserve orig_bytes number of bytes from the space info associated
984 * with the block_rsv. If there is not enough space it will make an attempt to
985 * flush out space to make room. It will do this by flushing delalloc if
986 * possible or committing the transaction. If flush is 0 then no attempts to
987 * regain reservations will be made and this will fail if there is not enough
990 static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
991 struct btrfs_space_info *space_info,
993 enum btrfs_reserve_flush_enum flush,
996 struct reserve_ticket ticket;
999 bool pending_tickets;
1002 ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
1004 spin_lock(&space_info->lock);
1006 used = btrfs_space_info_used(space_info, true);
1007 pending_tickets = !list_empty(&space_info->tickets) ||
1008 !list_empty(&space_info->priority_tickets);
1011 * Carry on if we have enough space (short-circuit) OR call
1012 * can_overcommit() to ensure we can overcommit to continue.
1014 if (!pending_tickets &&
1015 ((used + orig_bytes <= space_info->total_bytes) ||
1016 can_overcommit(fs_info, space_info, orig_bytes, flush,
1018 btrfs_space_info_update_bytes_may_use(fs_info, space_info,
1024 * If we couldn't make a reservation then setup our reservation ticket
1025 * and kick the async worker if it's not already running.
1027 * If we are a priority flusher then we just need to add our ticket to
1028 * the list and we will do our own flushing further down.
1030 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
1031 ticket.bytes = orig_bytes;
1033 init_waitqueue_head(&ticket.wait);
1034 if (flush == BTRFS_RESERVE_FLUSH_ALL) {
1035 list_add_tail(&ticket.list, &space_info->tickets);
1036 if (!space_info->flush) {
1037 space_info->flush = 1;
1038 trace_btrfs_trigger_flush(fs_info,
1042 queue_work(system_unbound_wq,
1043 &fs_info->async_reclaim_work);
1046 list_add_tail(&ticket.list,
1047 &space_info->priority_tickets);
1049 } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
1052 * We will do the space reservation dance during log replay,
1053 * which means we won't have fs_info->fs_root set, so don't do
1054 * the async reclaim as we will panic.
1056 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
1057 need_do_async_reclaim(fs_info, space_info,
1058 used, system_chunk) &&
1059 !work_busy(&fs_info->async_reclaim_work)) {
1060 trace_btrfs_trigger_flush(fs_info, space_info->flags,
1061 orig_bytes, flush, "preempt");
1062 queue_work(system_unbound_wq,
1063 &fs_info->async_reclaim_work);
1066 spin_unlock(&space_info->lock);
1067 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
1070 return handle_reserve_ticket(fs_info, space_info, &ticket, flush);
1074 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
1075 * @root - the root we're allocating for
1076 * @block_rsv - the block_rsv we're allocating for
1077 * @orig_bytes - the number of bytes we want
1078 * @flush - whether or not we can flush to make our reservation
1080 * This will reserve orig_bytes number of bytes from the space info associated
1081 * with the block_rsv. If there is not enough space it will make an attempt to
1082 * flush out space to make room. It will do this by flushing delalloc if
1083 * possible or committing the transaction. If flush is 0 then no attempts to
1084 * regain reservations will be made and this will fail if there is not enough
1087 int btrfs_reserve_metadata_bytes(struct btrfs_root *root,
1088 struct btrfs_block_rsv *block_rsv,
1090 enum btrfs_reserve_flush_enum flush)
1092 struct btrfs_fs_info *fs_info = root->fs_info;
1093 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
1095 bool system_chunk = (root == fs_info->chunk_root);
1097 ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info,
1098 orig_bytes, flush, system_chunk);
1099 if (ret == -ENOSPC &&
1100 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
1101 if (block_rsv != global_rsv &&
1102 !btrfs_block_rsv_use_bytes(global_rsv, orig_bytes))
1105 if (ret == -ENOSPC) {
1106 trace_btrfs_space_reservation(fs_info, "space_info:enospc",
1107 block_rsv->space_info->flags,
1110 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
1111 btrfs_dump_space_info(fs_info, block_rsv->space_info,