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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
13u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
14 bool may_use_included)
15{
16 ASSERT(s_info);
17 return s_info->bytes_used + s_info->bytes_reserved +
18 s_info->bytes_pinned + s_info->bytes_readonly +
19 (may_use_included ? s_info->bytes_may_use : 0);
20}
21
22/*
23 * after adding space to the filesystem, we need to clear the full flags
24 * on all the space infos.
25 */
26void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
27{
28 struct list_head *head = &info->space_info;
29 struct btrfs_space_info *found;
30
31 rcu_read_lock();
32 list_for_each_entry_rcu(found, head, list)
33 found->full = 0;
34 rcu_read_unlock();
35}
36
37static int create_space_info(struct btrfs_fs_info *info, u64 flags)
38{
39
40 struct btrfs_space_info *space_info;
41 int i;
42 int ret;
43
44 space_info = kzalloc(sizeof(*space_info), GFP_NOFS);
45 if (!space_info)
46 return -ENOMEM;
47
48 ret = percpu_counter_init(&space_info->total_bytes_pinned, 0,
49 GFP_KERNEL);
50 if (ret) {
51 kfree(space_info);
52 return ret;
53 }
54
55 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
56 INIT_LIST_HEAD(&space_info->block_groups[i]);
57 init_rwsem(&space_info->groups_sem);
58 spin_lock_init(&space_info->lock);
59 space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
60 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
61 init_waitqueue_head(&space_info->wait);
62 INIT_LIST_HEAD(&space_info->ro_bgs);
63 INIT_LIST_HEAD(&space_info->tickets);
64 INIT_LIST_HEAD(&space_info->priority_tickets);
65
66 ret = btrfs_sysfs_add_space_info_type(info, space_info);
67 if (ret)
68 return ret;
69
70 list_add_rcu(&space_info->list, &info->space_info);
71 if (flags & BTRFS_BLOCK_GROUP_DATA)
72 info->data_sinfo = space_info;
73
74 return ret;
75}
76
77int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
78{
79 struct btrfs_super_block *disk_super;
80 u64 features;
81 u64 flags;
82 int mixed = 0;
83 int ret;
84
85 disk_super = fs_info->super_copy;
86 if (!btrfs_super_root(disk_super))
87 return -EINVAL;
88
89 features = btrfs_super_incompat_flags(disk_super);
90 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
91 mixed = 1;
92
93 flags = BTRFS_BLOCK_GROUP_SYSTEM;
94 ret = create_space_info(fs_info, flags);
95 if (ret)
96 goto out;
97
98 if (mixed) {
99 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
100 ret = create_space_info(fs_info, flags);
101 } else {
102 flags = BTRFS_BLOCK_GROUP_METADATA;
103 ret = create_space_info(fs_info, flags);
104 if (ret)
105 goto out;
106
107 flags = BTRFS_BLOCK_GROUP_DATA;
108 ret = create_space_info(fs_info, flags);
109 }
110out:
111 return ret;
112}
113
114void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
115 u64 total_bytes, u64 bytes_used,
116 u64 bytes_readonly,
117 struct btrfs_space_info **space_info)
118{
119 struct btrfs_space_info *found;
120 int factor;
121
122 factor = btrfs_bg_type_to_factor(flags);
123
124 found = btrfs_find_space_info(info, flags);
125 ASSERT(found);
126 spin_lock(&found->lock);
127 found->total_bytes += total_bytes;
128 found->disk_total += total_bytes * factor;
129 found->bytes_used += bytes_used;
130 found->disk_used += bytes_used * factor;
131 found->bytes_readonly += bytes_readonly;
132 if (total_bytes > 0)
133 found->full = 0;
134 btrfs_try_granting_tickets(info, found);
135 spin_unlock(&found->lock);
136 *space_info = found;
137}
138
139struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
140 u64 flags)
141{
142 struct list_head *head = &info->space_info;
143 struct btrfs_space_info *found;
144
145 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
146
147 rcu_read_lock();
148 list_for_each_entry_rcu(found, head, list) {
149 if (found->flags & flags) {
150 rcu_read_unlock();
151 return found;
152 }
153 }
154 rcu_read_unlock();
155 return NULL;
156}
157
158static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
159{
160 return (global->size << 1);
161}
162
163static int can_overcommit(struct btrfs_fs_info *fs_info,
164 struct btrfs_space_info *space_info, u64 bytes,
165 enum btrfs_reserve_flush_enum flush,
166 bool system_chunk)
167{
168 u64 profile;
169 u64 avail;
170 u64 used;
171 int factor;
172
173 /* Don't overcommit when in mixed mode. */
174 if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
175 return 0;
176
177 if (system_chunk)
178 profile = btrfs_system_alloc_profile(fs_info);
179 else
180 profile = btrfs_metadata_alloc_profile(fs_info);
181
182 used = btrfs_space_info_used(space_info, true);
183 avail = atomic64_read(&fs_info->free_chunk_space);
184
185 /*
186 * If we have dup, raid1 or raid10 then only half of the free
187 * space is actually usable. For raid56, the space info used
188 * doesn't include the parity drive, so we don't have to
189 * change the math
190 */
191 factor = btrfs_bg_type_to_factor(profile);
192 avail = div_u64(avail, factor);
193
194 /*
195 * If we aren't flushing all things, let us overcommit up to
196 * 1/2th of the space. If we can flush, don't let us overcommit
197 * too much, let it overcommit up to 1/8 of the space.
198 */
199 if (flush == BTRFS_RESERVE_FLUSH_ALL)
200 avail >>= 3;
201 else
202 avail >>= 1;
203
204 if (used + bytes < space_info->total_bytes + avail)
205 return 1;
206 return 0;
207}
208
209/*
210 * This is for space we already have accounted in space_info->bytes_may_use, so
211 * basically when we're returning space from block_rsv's.
212 */
213void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
214 struct btrfs_space_info *space_info)
215{
216 struct list_head *head;
217 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
218
219 lockdep_assert_held(&space_info->lock);
220
221 head = &space_info->priority_tickets;
222again:
223 while (!list_empty(head)) {
224 struct reserve_ticket *ticket;
225 u64 used = btrfs_space_info_used(space_info, true);
226
227 ticket = list_first_entry(head, struct reserve_ticket, list);
228
229 /* Check and see if our ticket can be satisified now. */
230 if ((used + ticket->bytes <= space_info->total_bytes) ||
231 can_overcommit(fs_info, space_info, ticket->bytes, flush,
232 false)) {
233 btrfs_space_info_update_bytes_may_use(fs_info,
234 space_info,
235 ticket->bytes);
236 list_del_init(&ticket->list);
237 ticket->bytes = 0;
238 space_info->tickets_id++;
239 wake_up(&ticket->wait);
240 } else {
241 break;
242 }
243 }
244
245 if (head == &space_info->priority_tickets) {
246 head = &space_info->tickets;
247 flush = BTRFS_RESERVE_FLUSH_ALL;
248 goto again;
249 }
250}
251
252#define DUMP_BLOCK_RSV(fs_info, rsv_name) \
253do { \
254 struct btrfs_block_rsv *__rsv = &(fs_info)->rsv_name; \
255 spin_lock(&__rsv->lock); \
256 btrfs_info(fs_info, #rsv_name ": size %llu reserved %llu", \
257 __rsv->size, __rsv->reserved); \
258 spin_unlock(&__rsv->lock); \
259} while (0)
260
261static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
262 struct btrfs_space_info *info)
263{
264 lockdep_assert_held(&info->lock);
265
266 btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull",
267 info->flags,
268 info->total_bytes - btrfs_space_info_used(info, true),
269 info->full ? "" : "not ");
270 btrfs_info(fs_info,
271 "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
272 info->total_bytes, info->bytes_used, info->bytes_pinned,
273 info->bytes_reserved, info->bytes_may_use,
274 info->bytes_readonly);
275
276 DUMP_BLOCK_RSV(fs_info, global_block_rsv);
277 DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
278 DUMP_BLOCK_RSV(fs_info, chunk_block_rsv);
279 DUMP_BLOCK_RSV(fs_info, delayed_block_rsv);
280 DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv);
281
282}
283
284void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
285 struct btrfs_space_info *info, u64 bytes,
286 int dump_block_groups)
287{
288 struct btrfs_block_group_cache *cache;
289 int index = 0;
290
291 spin_lock(&info->lock);
292 __btrfs_dump_space_info(fs_info, info);
293 spin_unlock(&info->lock);
294
295 if (!dump_block_groups)
296 return;
297
298 down_read(&info->groups_sem);
299again:
300 list_for_each_entry(cache, &info->block_groups[index], list) {
301 spin_lock(&cache->lock);
302 btrfs_info(fs_info,
303 "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
304 cache->key.objectid, cache->key.offset,
305 btrfs_block_group_used(&cache->item), cache->pinned,
306 cache->reserved, cache->ro ? "[readonly]" : "");
307 btrfs_dump_free_space(cache, bytes);
308 spin_unlock(&cache->lock);
309 }
310 if (++index < BTRFS_NR_RAID_TYPES)
311 goto again;
312 up_read(&info->groups_sem);
313}
314
315static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info,
316 unsigned long nr_pages, int nr_items)
317{
318 struct super_block *sb = fs_info->sb;
319
320 if (down_read_trylock(&sb->s_umount)) {
321 writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
322 up_read(&sb->s_umount);
323 } else {
324 /*
325 * We needn't worry the filesystem going from r/w to r/o though
326 * we don't acquire ->s_umount mutex, because the filesystem
327 * should guarantee the delalloc inodes list be empty after
328 * the filesystem is readonly(all dirty pages are written to
329 * the disk).
330 */
331 btrfs_start_delalloc_roots(fs_info, nr_items);
332 if (!current->journal_info)
333 btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1);
334 }
335}
336
337static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
338 u64 to_reclaim)
339{
340 u64 bytes;
341 u64 nr;
342
343 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
344 nr = div64_u64(to_reclaim, bytes);
345 if (!nr)
346 nr = 1;
347 return nr;
348}
349
350#define EXTENT_SIZE_PER_ITEM SZ_256K
351
352/*
353 * shrink metadata reservation for delalloc
354 */
355static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim,
356 u64 orig, bool wait_ordered)
357{
358 struct btrfs_space_info *space_info;
359 struct btrfs_trans_handle *trans;
360 u64 delalloc_bytes;
361 u64 dio_bytes;
362 u64 async_pages;
363 u64 items;
364 long time_left;
365 unsigned long nr_pages;
366 int loops;
367
368 /* Calc the number of the pages we need flush for space reservation */
369 items = calc_reclaim_items_nr(fs_info, to_reclaim);
370 to_reclaim = items * EXTENT_SIZE_PER_ITEM;
371
372 trans = (struct btrfs_trans_handle *)current->journal_info;
373 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
374
375 delalloc_bytes = percpu_counter_sum_positive(
376 &fs_info->delalloc_bytes);
377 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes);
378 if (delalloc_bytes == 0 && dio_bytes == 0) {
379 if (trans)
380 return;
381 if (wait_ordered)
382 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
383 return;
384 }
385
386 /*
387 * If we are doing more ordered than delalloc we need to just wait on
388 * ordered extents, otherwise we'll waste time trying to flush delalloc
389 * that likely won't give us the space back we need.
390 */
391 if (dio_bytes > delalloc_bytes)
392 wait_ordered = true;
393
394 loops = 0;
395 while ((delalloc_bytes || dio_bytes) && loops < 3) {
396 nr_pages = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT;
397
398 /*
399 * Triggers inode writeback for up to nr_pages. This will invoke
400 * ->writepages callback and trigger delalloc filling
401 * (btrfs_run_delalloc_range()).
402 */
403 btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items);
404
405 /*
406 * We need to wait for the compressed pages to start before
407 * we continue.
408 */
409 async_pages = atomic_read(&fs_info->async_delalloc_pages);
410 if (!async_pages)
411 goto skip_async;
412
413 /*
414 * Calculate how many compressed pages we want to be written
415 * before we continue. I.e if there are more async pages than we
416 * require wait_event will wait until nr_pages are written.
417 */
418 if (async_pages <= nr_pages)
419 async_pages = 0;
420 else
421 async_pages -= nr_pages;
422
423 wait_event(fs_info->async_submit_wait,
424 atomic_read(&fs_info->async_delalloc_pages) <=
425 (int)async_pages);
426skip_async:
427 spin_lock(&space_info->lock);
428 if (list_empty(&space_info->tickets) &&
429 list_empty(&space_info->priority_tickets)) {
430 spin_unlock(&space_info->lock);
431 break;
432 }
433 spin_unlock(&space_info->lock);
434
435 loops++;
436 if (wait_ordered && !trans) {
437 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
438 } else {
439 time_left = schedule_timeout_killable(1);
440 if (time_left)
441 break;
442 }
443 delalloc_bytes = percpu_counter_sum_positive(
444 &fs_info->delalloc_bytes);
445 dio_bytes = percpu_counter_sum_positive(&fs_info->dio_bytes);
446 }
447}
448
449/**
450 * maybe_commit_transaction - possibly commit the transaction if its ok to
451 * @root - the root we're allocating for
452 * @bytes - the number of bytes we want to reserve
453 * @force - force the commit
454 *
455 * This will check to make sure that committing the transaction will actually
456 * get us somewhere and then commit the transaction if it does. Otherwise it
457 * will return -ENOSPC.
458 */
459static int may_commit_transaction(struct btrfs_fs_info *fs_info,
460 struct btrfs_space_info *space_info)
461{
462 struct reserve_ticket *ticket = NULL;
463 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv;
464 struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
465 struct btrfs_trans_handle *trans;
466 u64 bytes_needed;
467 u64 reclaim_bytes = 0;
468 u64 cur_free_bytes = 0;
469
470 trans = (struct btrfs_trans_handle *)current->journal_info;
471 if (trans)
472 return -EAGAIN;
473
474 spin_lock(&space_info->lock);
475 cur_free_bytes = btrfs_space_info_used(space_info, true);
476 if (cur_free_bytes < space_info->total_bytes)
477 cur_free_bytes = space_info->total_bytes - cur_free_bytes;
478 else
479 cur_free_bytes = 0;
480
481 if (!list_empty(&space_info->priority_tickets))
482 ticket = list_first_entry(&space_info->priority_tickets,
483 struct reserve_ticket, list);
484 else if (!list_empty(&space_info->tickets))
485 ticket = list_first_entry(&space_info->tickets,
486 struct reserve_ticket, list);
487 bytes_needed = (ticket) ? ticket->bytes : 0;
488
489 if (bytes_needed > cur_free_bytes)
490 bytes_needed -= cur_free_bytes;
491 else
492 bytes_needed = 0;
493 spin_unlock(&space_info->lock);
494
495 if (!bytes_needed)
496 return 0;
497
498 trans = btrfs_join_transaction(fs_info->extent_root);
499 if (IS_ERR(trans))
500 return PTR_ERR(trans);
501
502 /*
503 * See if there is enough pinned space to make this reservation, or if
504 * we have block groups that are going to be freed, allowing us to
505 * possibly do a chunk allocation the next loop through.
506 */
507 if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags) ||
508 __percpu_counter_compare(&space_info->total_bytes_pinned,
509 bytes_needed,
510 BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0)
511 goto commit;
512
513 /*
514 * See if there is some space in the delayed insertion reservation for
515 * this reservation.
516 */
517 if (space_info != delayed_rsv->space_info)
518 goto enospc;
519
520 spin_lock(&delayed_rsv->lock);
521 reclaim_bytes += delayed_rsv->reserved;
522 spin_unlock(&delayed_rsv->lock);
523
524 spin_lock(&delayed_refs_rsv->lock);
525 reclaim_bytes += delayed_refs_rsv->reserved;
526 spin_unlock(&delayed_refs_rsv->lock);
527 if (reclaim_bytes >= bytes_needed)
528 goto commit;
529 bytes_needed -= reclaim_bytes;
530
531 if (__percpu_counter_compare(&space_info->total_bytes_pinned,
532 bytes_needed,
533 BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0)
534 goto enospc;
535
536commit:
537 return btrfs_commit_transaction(trans);
538enospc:
539 btrfs_end_transaction(trans);
540 return -ENOSPC;
541}
542
543/*
544 * Try to flush some data based on policy set by @state. This is only advisory
545 * and may fail for various reasons. The caller is supposed to examine the
546 * state of @space_info to detect the outcome.
547 */
548static void flush_space(struct btrfs_fs_info *fs_info,
549 struct btrfs_space_info *space_info, u64 num_bytes,
550 int state)
551{
552 struct btrfs_root *root = fs_info->extent_root;
553 struct btrfs_trans_handle *trans;
554 int nr;
555 int ret = 0;
556
557 switch (state) {
558 case FLUSH_DELAYED_ITEMS_NR:
559 case FLUSH_DELAYED_ITEMS:
560 if (state == FLUSH_DELAYED_ITEMS_NR)
561 nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
562 else
563 nr = -1;
564
565 trans = btrfs_join_transaction(root);
566 if (IS_ERR(trans)) {
567 ret = PTR_ERR(trans);
568 break;
569 }
570 ret = btrfs_run_delayed_items_nr(trans, nr);
571 btrfs_end_transaction(trans);
572 break;
573 case FLUSH_DELALLOC:
574 case FLUSH_DELALLOC_WAIT:
575 shrink_delalloc(fs_info, num_bytes * 2, num_bytes,
576 state == FLUSH_DELALLOC_WAIT);
577 break;
578 case FLUSH_DELAYED_REFS_NR:
579 case FLUSH_DELAYED_REFS:
580 trans = btrfs_join_transaction(root);
581 if (IS_ERR(trans)) {
582 ret = PTR_ERR(trans);
583 break;
584 }
585 if (state == FLUSH_DELAYED_REFS_NR)
586 nr = calc_reclaim_items_nr(fs_info, num_bytes);
587 else
588 nr = 0;
589 btrfs_run_delayed_refs(trans, nr);
590 btrfs_end_transaction(trans);
591 break;
592 case ALLOC_CHUNK:
593 case ALLOC_CHUNK_FORCE:
594 trans = btrfs_join_transaction(root);
595 if (IS_ERR(trans)) {
596 ret = PTR_ERR(trans);
597 break;
598 }
599 ret = btrfs_chunk_alloc(trans,
600 btrfs_metadata_alloc_profile(fs_info),
601 (state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE :
602 CHUNK_ALLOC_FORCE);
603 btrfs_end_transaction(trans);
604 if (ret > 0 || ret == -ENOSPC)
605 ret = 0;
606 break;
607 case RUN_DELAYED_IPUTS:
608 /*
609 * If we have pending delayed iputs then we could free up a
610 * bunch of pinned space, so make sure we run the iputs before
611 * we do our pinned bytes check below.
612 */
613 btrfs_run_delayed_iputs(fs_info);
614 btrfs_wait_on_delayed_iputs(fs_info);
615 break;
616 case COMMIT_TRANS:
617 ret = may_commit_transaction(fs_info, space_info);
618 break;
619 default:
620 ret = -ENOSPC;
621 break;
622 }
623
624 trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state,
625 ret);
626 return;
627}
628
629static inline u64
630btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
631 struct btrfs_space_info *space_info,
632 bool system_chunk)
633{
634 struct reserve_ticket *ticket;
635 u64 used;
636 u64 expected;
637 u64 to_reclaim = 0;
638
639 list_for_each_entry(ticket, &space_info->tickets, list)
640 to_reclaim += ticket->bytes;
641 list_for_each_entry(ticket, &space_info->priority_tickets, list)
642 to_reclaim += ticket->bytes;
643 if (to_reclaim)
644 return to_reclaim;
645
646 to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M);
647 if (can_overcommit(fs_info, space_info, to_reclaim,
648 BTRFS_RESERVE_FLUSH_ALL, system_chunk))
649 return 0;
650
651 used = btrfs_space_info_used(space_info, true);
652
653 if (can_overcommit(fs_info, space_info, SZ_1M,
654 BTRFS_RESERVE_FLUSH_ALL, system_chunk))
655 expected = div_factor_fine(space_info->total_bytes, 95);
656 else
657 expected = div_factor_fine(space_info->total_bytes, 90);
658
659 if (used > expected)
660 to_reclaim = used - expected;
661 else
662 to_reclaim = 0;
663 to_reclaim = min(to_reclaim, space_info->bytes_may_use +
664 space_info->bytes_reserved);
665 return to_reclaim;
666}
667
668static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info,
669 struct btrfs_space_info *space_info,
670 u64 used, bool system_chunk)
671{
672 u64 thresh = div_factor_fine(space_info->total_bytes, 98);
673
674 /* If we're just plain full then async reclaim just slows us down. */
675 if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh)
676 return 0;
677
678 if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info,
679 system_chunk))
680 return 0;
681
682 return (used >= thresh && !btrfs_fs_closing(fs_info) &&
683 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
684}
685
686/*
687 * maybe_fail_all_tickets - we've exhausted our flushing, start failing tickets
688 * @fs_info - fs_info for this fs
689 * @space_info - the space info we were flushing
690 *
691 * We call this when we've exhausted our flushing ability and haven't made
692 * progress in satisfying tickets. The reservation code handles tickets in
693 * order, so if there is a large ticket first and then smaller ones we could
694 * very well satisfy the smaller tickets. This will attempt to wake up any
695 * tickets in the list to catch this case.
696 *
697 * This function returns true if it was able to make progress by clearing out
698 * other tickets, or if it stumbles across a ticket that was smaller than the
699 * first ticket.
700 */
701static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info,
702 struct btrfs_space_info *space_info)
703{
704 struct reserve_ticket *ticket;
705 u64 tickets_id = space_info->tickets_id;
706 u64 first_ticket_bytes = 0;
707
708 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
709 btrfs_info(fs_info, "cannot satisfy tickets, dumping space info");
710 __btrfs_dump_space_info(fs_info, space_info);
711 }
712
713 while (!list_empty(&space_info->tickets) &&
714 tickets_id == space_info->tickets_id) {
715 ticket = list_first_entry(&space_info->tickets,
716 struct reserve_ticket, list);
717
718 /*
719 * may_commit_transaction will avoid committing the transaction
720 * if it doesn't feel like the space reclaimed by the commit
721 * would result in the ticket succeeding. However if we have a
722 * smaller ticket in the queue it may be small enough to be
723 * satisified by committing the transaction, so if any
724 * subsequent ticket is smaller than the first ticket go ahead
725 * and send us back for another loop through the enospc flushing
726 * code.
727 */
728 if (first_ticket_bytes == 0)
729 first_ticket_bytes = ticket->bytes;
730 else if (first_ticket_bytes > ticket->bytes)
731 return true;
732
733 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
734 btrfs_info(fs_info, "failing ticket with %llu bytes",
735 ticket->bytes);
736
737 list_del_init(&ticket->list);
738 ticket->error = -ENOSPC;
739 wake_up(&ticket->wait);
740
741 /*
742 * We're just throwing tickets away, so more flushing may not
743 * trip over btrfs_try_granting_tickets, so we need to call it
744 * here to see if we can make progress with the next ticket in
745 * the list.
746 */
747 btrfs_try_granting_tickets(fs_info, space_info);
748 }
749 return (tickets_id != space_info->tickets_id);
750}
751
752/*
753 * This is for normal flushers, we can wait all goddamned day if we want to. We
754 * will loop and continuously try to flush as long as we are making progress.
755 * We count progress as clearing off tickets each time we have to loop.
756 */
757static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
758{
759 struct btrfs_fs_info *fs_info;
760 struct btrfs_space_info *space_info;
761 u64 to_reclaim;
762 int flush_state;
763 int commit_cycles = 0;
764 u64 last_tickets_id;
765
766 fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
767 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
768
769 spin_lock(&space_info->lock);
770 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
771 false);
772 if (!to_reclaim) {
773 space_info->flush = 0;
774 spin_unlock(&space_info->lock);
775 return;
776 }
777 last_tickets_id = space_info->tickets_id;
778 spin_unlock(&space_info->lock);
779
780 flush_state = FLUSH_DELAYED_ITEMS_NR;
781 do {
782 flush_space(fs_info, space_info, to_reclaim, flush_state);
783 spin_lock(&space_info->lock);
784 if (list_empty(&space_info->tickets)) {
785 space_info->flush = 0;
786 spin_unlock(&space_info->lock);
787 return;
788 }
789 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info,
790 space_info,
791 false);
792 if (last_tickets_id == space_info->tickets_id) {
793 flush_state++;
794 } else {
795 last_tickets_id = space_info->tickets_id;
796 flush_state = FLUSH_DELAYED_ITEMS_NR;
797 if (commit_cycles)
798 commit_cycles--;
799 }
800
801 /*
802 * We don't want to force a chunk allocation until we've tried
803 * pretty hard to reclaim space. Think of the case where we
804 * freed up a bunch of space and so have a lot of pinned space
805 * to reclaim. We would rather use that than possibly create a
806 * underutilized metadata chunk. So if this is our first run
807 * through the flushing state machine skip ALLOC_CHUNK_FORCE and
808 * commit the transaction. If nothing has changed the next go
809 * around then we can force a chunk allocation.
810 */
811 if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles)
812 flush_state++;
813
814 if (flush_state > COMMIT_TRANS) {
815 commit_cycles++;
816 if (commit_cycles > 2) {
817 if (maybe_fail_all_tickets(fs_info, space_info)) {
818 flush_state = FLUSH_DELAYED_ITEMS_NR;
819 commit_cycles--;
820 } else {
821 space_info->flush = 0;
822 }
823 } else {
824 flush_state = FLUSH_DELAYED_ITEMS_NR;
825 }
826 }
827 spin_unlock(&space_info->lock);
828 } while (flush_state <= COMMIT_TRANS);
829}
830
831void btrfs_init_async_reclaim_work(struct work_struct *work)
832{
833 INIT_WORK(work, btrfs_async_reclaim_metadata_space);
834}
835
836static const enum btrfs_flush_state priority_flush_states[] = {
837 FLUSH_DELAYED_ITEMS_NR,
838 FLUSH_DELAYED_ITEMS,
839 ALLOC_CHUNK,
840};
841
842static const enum btrfs_flush_state evict_flush_states[] = {
843 FLUSH_DELAYED_ITEMS_NR,
844 FLUSH_DELAYED_ITEMS,
845 FLUSH_DELAYED_REFS_NR,
846 FLUSH_DELAYED_REFS,
847 FLUSH_DELALLOC,
848 FLUSH_DELALLOC_WAIT,
849 ALLOC_CHUNK,
850 COMMIT_TRANS,
851};
852
853static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
854 struct btrfs_space_info *space_info,
855 struct reserve_ticket *ticket,
856 const enum btrfs_flush_state *states,
857 int states_nr)
858{
859 u64 to_reclaim;
860 int flush_state;
861
862 spin_lock(&space_info->lock);
863 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
864 false);
865 if (!to_reclaim) {
866 spin_unlock(&space_info->lock);
867 return;
868 }
869 spin_unlock(&space_info->lock);
870
871 flush_state = 0;
872 do {
873 flush_space(fs_info, space_info, to_reclaim, states[flush_state]);
874 flush_state++;
875 spin_lock(&space_info->lock);
876 if (ticket->bytes == 0) {
877 spin_unlock(&space_info->lock);
878 return;
879 }
880 spin_unlock(&space_info->lock);
881 } while (flush_state < states_nr);
882}
883
884static void wait_reserve_ticket(struct btrfs_fs_info *fs_info,
885 struct btrfs_space_info *space_info,
886 struct reserve_ticket *ticket)
887
888{
889 DEFINE_WAIT(wait);
890 int ret = 0;
891
892 spin_lock(&space_info->lock);
893 while (ticket->bytes > 0 && ticket->error == 0) {
894 ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
895 if (ret) {
896 /*
897 * Delete us from the list. After we unlock the space
898 * info, we don't want the async reclaim job to reserve
899 * space for this ticket. If that would happen, then the
900 * ticket's task would not known that space was reserved
901 * despite getting an error, resulting in a space leak
902 * (bytes_may_use counter of our space_info).
903 */
904 list_del_init(&ticket->list);
905 ticket->error = -EINTR;
906 break;
907 }
908 spin_unlock(&space_info->lock);
909
910 schedule();
911
912 finish_wait(&ticket->wait, &wait);
913 spin_lock(&space_info->lock);
914 }
915 spin_unlock(&space_info->lock);
916}
917
918/**
919 * handle_reserve_ticket - do the appropriate flushing and waiting for a ticket
920 * @fs_info - the fs
921 * @space_info - the space_info for the reservation
922 * @ticket - the ticket for the reservation
923 * @flush - how much we can flush
924 *
925 * This does the work of figuring out how to flush for the ticket, waiting for
926 * the reservation, and returning the appropriate error if there is one.
927 */
928static int handle_reserve_ticket(struct btrfs_fs_info *fs_info,
929 struct btrfs_space_info *space_info,
930 struct reserve_ticket *ticket,
931 enum btrfs_reserve_flush_enum flush)
932{
933 int ret;
934
935 switch (flush) {
936 case BTRFS_RESERVE_FLUSH_ALL:
937 wait_reserve_ticket(fs_info, space_info, ticket);
938 break;
939 case BTRFS_RESERVE_FLUSH_LIMIT:
940 priority_reclaim_metadata_space(fs_info, space_info, ticket,
941 priority_flush_states,
942 ARRAY_SIZE(priority_flush_states));
943 break;
944 case BTRFS_RESERVE_FLUSH_EVICT:
945 priority_reclaim_metadata_space(fs_info, space_info, ticket,
946 evict_flush_states,
947 ARRAY_SIZE(evict_flush_states));
948 break;
949 default:
950 ASSERT(0);
951 break;
952 }
953
954 spin_lock(&space_info->lock);
955 ret = ticket->error;
956 if (ticket->bytes || ticket->error) {
957 /*
958 * Need to delete here for priority tickets. For regular tickets
959 * either the async reclaim job deletes the ticket from the list
960 * or we delete it ourselves at wait_reserve_ticket().
961 */
962 list_del_init(&ticket->list);
963 if (!ret)
964 ret = -ENOSPC;
965 }
966 spin_unlock(&space_info->lock);
967 ASSERT(list_empty(&ticket->list));
968 /*
969 * Check that we can't have an error set if the reservation succeeded,
970 * as that would confuse tasks and lead them to error out without
971 * releasing reserved space (if an error happens the expectation is that
972 * space wasn't reserved at all).
973 */
974 ASSERT(!(ticket->bytes == 0 && ticket->error));
975 return ret;
976}
977
978/**
979 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
980 * @root - the root we're allocating for
981 * @space_info - the space info we want to allocate from
982 * @orig_bytes - the number of bytes we want
983 * @flush - whether or not we can flush to make our reservation
984 *
985 * This will reserve orig_bytes number of bytes from the space info associated
986 * with the block_rsv. If there is not enough space it will make an attempt to
987 * flush out space to make room. It will do this by flushing delalloc if
988 * possible or committing the transaction. If flush is 0 then no attempts to
989 * regain reservations will be made and this will fail if there is not enough
990 * space already.
991 */
992static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
993 struct btrfs_space_info *space_info,
994 u64 orig_bytes,
995 enum btrfs_reserve_flush_enum flush,
996 bool system_chunk)
997{
998 struct reserve_ticket ticket;
999 u64 used;
1000 int ret = 0;
1001 bool pending_tickets;
1002
1003 ASSERT(orig_bytes);
1004 ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
1005
1006 spin_lock(&space_info->lock);
1007 ret = -ENOSPC;
1008 used = btrfs_space_info_used(space_info, true);
1009 pending_tickets = !list_empty(&space_info->tickets) ||
1010 !list_empty(&space_info->priority_tickets);
1011
1012 /*
1013 * Carry on if we have enough space (short-circuit) OR call
1014 * can_overcommit() to ensure we can overcommit to continue.
1015 */
1016 if (!pending_tickets &&
1017 ((used + orig_bytes <= space_info->total_bytes) ||
1018 can_overcommit(fs_info, space_info, orig_bytes, flush,
1019 system_chunk))) {
1020 btrfs_space_info_update_bytes_may_use(fs_info, space_info,
1021 orig_bytes);
1022 ret = 0;
1023 }
1024
1025 /*
1026 * If we couldn't make a reservation then setup our reservation ticket
1027 * and kick the async worker if it's not already running.
1028 *
1029 * If we are a priority flusher then we just need to add our ticket to
1030 * the list and we will do our own flushing further down.
1031 */
1032 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
1033 ticket.bytes = orig_bytes;
1034 ticket.error = 0;
1035 init_waitqueue_head(&ticket.wait);
1036 if (flush == BTRFS_RESERVE_FLUSH_ALL) {
1037 list_add_tail(&ticket.list, &space_info->tickets);
1038 if (!space_info->flush) {
1039 space_info->flush = 1;
1040 trace_btrfs_trigger_flush(fs_info,
1041 space_info->flags,
1042 orig_bytes, flush,
1043 "enospc");
1044 queue_work(system_unbound_wq,
1045 &fs_info->async_reclaim_work);
1046 }
1047 } else {
1048 list_add_tail(&ticket.list,
1049 &space_info->priority_tickets);
1050 }
1051 } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
1052 used += orig_bytes;
1053 /*
1054 * We will do the space reservation dance during log replay,
1055 * which means we won't have fs_info->fs_root set, so don't do
1056 * the async reclaim as we will panic.
1057 */
1058 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
1059 need_do_async_reclaim(fs_info, space_info,
1060 used, system_chunk) &&
1061 !work_busy(&fs_info->async_reclaim_work)) {
1062 trace_btrfs_trigger_flush(fs_info, space_info->flags,
1063 orig_bytes, flush, "preempt");
1064 queue_work(system_unbound_wq,
1065 &fs_info->async_reclaim_work);
1066 }
1067 }
1068 spin_unlock(&space_info->lock);
1069 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
1070 return ret;
1071
1072 return handle_reserve_ticket(fs_info, space_info, &ticket, flush);
1073}
1074
1075/**
1076 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
1077 * @root - the root we're allocating for
1078 * @block_rsv - the block_rsv we're allocating for
1079 * @orig_bytes - the number of bytes we want
1080 * @flush - whether or not we can flush to make our reservation
1081 *
1082 * This will reserve orig_bytes number of bytes from the space info associated
1083 * with the block_rsv. If there is not enough space it will make an attempt to
1084 * flush out space to make room. It will do this by flushing delalloc if
1085 * possible or committing the transaction. If flush is 0 then no attempts to
1086 * regain reservations will be made and this will fail if there is not enough
1087 * space already.
1088 */
1089int btrfs_reserve_metadata_bytes(struct btrfs_root *root,
1090 struct btrfs_block_rsv *block_rsv,
1091 u64 orig_bytes,
1092 enum btrfs_reserve_flush_enum flush)
1093{
1094 struct btrfs_fs_info *fs_info = root->fs_info;
1095 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
1096 int ret;
1097 bool system_chunk = (root == fs_info->chunk_root);
1098
1099 ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info,
1100 orig_bytes, flush, system_chunk);
1101 if (ret == -ENOSPC &&
1102 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
1103 if (block_rsv != global_rsv &&
1104 !btrfs_block_rsv_use_bytes(global_rsv, orig_bytes))
1105 ret = 0;
1106 }
1107 if (ret == -ENOSPC) {
1108 trace_btrfs_space_reservation(fs_info, "space_info:enospc",
1109 block_rsv->space_info->flags,
1110 orig_bytes, 1);
1111
1112 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
1113 btrfs_dump_space_info(fs_info, block_rsv->space_info,
1114 orig_bytes, 0);
1115 }
1116 return ret;
1117}