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Update bcachefs sources to 7958ebe324 bcachefs: Fix alloc_v4_backpointers()
[bcachefs-tools-debian] / libbcachefs / alloc_foreground.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2012 Google, Inc.
4  *
5  * Foreground allocator code: allocate buckets from freelist, and allocate in
6  * sector granularity from writepoints.
7  *
8  * bch2_bucket_alloc() allocates a single bucket from a specific device.
9  *
10  * bch2_bucket_alloc_set() allocates one or more buckets from different devices
11  * in a given filesystem.
12  */
13
14 #include "bcachefs.h"
15 #include "alloc_background.h"
16 #include "alloc_foreground.h"
17 #include "backpointers.h"
18 #include "btree_iter.h"
19 #include "btree_update.h"
20 #include "btree_gc.h"
21 #include "buckets.h"
22 #include "buckets_waiting_for_journal.h"
23 #include "clock.h"
24 #include "debug.h"
25 #include "disk_groups.h"
26 #include "ec.h"
27 #include "error.h"
28 #include "io.h"
29 #include "journal.h"
30 #include "movinggc.h"
31 #include "nocow_locking.h"
32
33 #include <linux/math64.h>
34 #include <linux/rculist.h>
35 #include <linux/rcupdate.h>
36 #include <trace/events/bcachefs.h>
37
38 const char * const bch2_alloc_reserves[] = {
39 #define x(t) #t,
40         BCH_ALLOC_RESERVES()
41 #undef x
42         NULL
43 };
44
45 /*
46  * Open buckets represent a bucket that's currently being allocated from.  They
47  * serve two purposes:
48  *
49  *  - They track buckets that have been partially allocated, allowing for
50  *    sub-bucket sized allocations - they're used by the sector allocator below
51  *
52  *  - They provide a reference to the buckets they own that mark and sweep GC
53  *    can find, until the new allocation has a pointer to it inserted into the
54  *    btree
55  *
56  * When allocating some space with the sector allocator, the allocation comes
57  * with a reference to an open bucket - the caller is required to put that
58  * reference _after_ doing the index update that makes its allocation reachable.
59  */
60
61 static void bch2_open_bucket_hash_add(struct bch_fs *c, struct open_bucket *ob)
62 {
63         open_bucket_idx_t idx = ob - c->open_buckets;
64         open_bucket_idx_t *slot = open_bucket_hashslot(c, ob->dev, ob->bucket);
65
66         ob->hash = *slot;
67         *slot = idx;
68 }
69
70 static void bch2_open_bucket_hash_remove(struct bch_fs *c, struct open_bucket *ob)
71 {
72         open_bucket_idx_t idx = ob - c->open_buckets;
73         open_bucket_idx_t *slot = open_bucket_hashslot(c, ob->dev, ob->bucket);
74
75         while (*slot != idx) {
76                 BUG_ON(!*slot);
77                 slot = &c->open_buckets[*slot].hash;
78         }
79
80         *slot = ob->hash;
81         ob->hash = 0;
82 }
83
84 void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
85 {
86         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
87
88         if (ob->ec) {
89                 bch2_ec_bucket_written(c, ob);
90                 return;
91         }
92
93         percpu_down_read(&c->mark_lock);
94         spin_lock(&ob->lock);
95
96         ob->valid = false;
97         ob->data_type = 0;
98
99         spin_unlock(&ob->lock);
100         percpu_up_read(&c->mark_lock);
101
102         spin_lock(&c->freelist_lock);
103         bch2_open_bucket_hash_remove(c, ob);
104
105         ob->freelist = c->open_buckets_freelist;
106         c->open_buckets_freelist = ob - c->open_buckets;
107
108         c->open_buckets_nr_free++;
109         ca->nr_open_buckets--;
110         spin_unlock(&c->freelist_lock);
111
112         closure_wake_up(&c->open_buckets_wait);
113 }
114
115 void bch2_open_bucket_write_error(struct bch_fs *c,
116                                   struct open_buckets *obs,
117                                   unsigned dev)
118 {
119         struct open_bucket *ob;
120         unsigned i;
121
122         open_bucket_for_each(c, obs, ob, i)
123                 if (ob->dev == dev && ob->ec)
124                         bch2_ec_bucket_cancel(c, ob);
125 }
126
127 static struct open_bucket *bch2_open_bucket_alloc(struct bch_fs *c)
128 {
129         struct open_bucket *ob;
130
131         BUG_ON(!c->open_buckets_freelist || !c->open_buckets_nr_free);
132
133         ob = c->open_buckets + c->open_buckets_freelist;
134         c->open_buckets_freelist = ob->freelist;
135         atomic_set(&ob->pin, 1);
136         ob->data_type = 0;
137
138         c->open_buckets_nr_free--;
139         return ob;
140 }
141
142 static void open_bucket_free_unused(struct bch_fs *c,
143                                     struct write_point *wp,
144                                     struct open_bucket *ob)
145 {
146         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
147         bool may_realloc = wp->data_type == BCH_DATA_user;
148
149         BUG_ON(ca->open_buckets_partial_nr >
150                ARRAY_SIZE(ca->open_buckets_partial));
151
152         if (ca->open_buckets_partial_nr <
153             ARRAY_SIZE(ca->open_buckets_partial) &&
154             may_realloc) {
155                 spin_lock(&c->freelist_lock);
156                 ob->on_partial_list = true;
157                 ca->open_buckets_partial[ca->open_buckets_partial_nr++] =
158                         ob - c->open_buckets;
159                 spin_unlock(&c->freelist_lock);
160
161                 closure_wake_up(&c->open_buckets_wait);
162                 closure_wake_up(&c->freelist_wait);
163         } else {
164                 bch2_open_bucket_put(c, ob);
165         }
166 }
167
168 /* _only_ for allocating the journal on a new device: */
169 long bch2_bucket_alloc_new_fs(struct bch_dev *ca)
170 {
171         while (ca->new_fs_bucket_idx < ca->mi.nbuckets) {
172                 u64 b = ca->new_fs_bucket_idx++;
173
174                 if (!is_superblock_bucket(ca, b) &&
175                     (!ca->buckets_nouse || !test_bit(b, ca->buckets_nouse)))
176                         return b;
177         }
178
179         return -1;
180 }
181
182 static inline unsigned open_buckets_reserved(enum alloc_reserve reserve)
183 {
184         switch (reserve) {
185         case RESERVE_btree:
186         case RESERVE_btree_movinggc:
187                 return 0;
188         case RESERVE_movinggc:
189                 return OPEN_BUCKETS_COUNT / 4;
190         default:
191                 return OPEN_BUCKETS_COUNT / 2;
192         }
193 }
194
195 static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *ca,
196                                               u64 bucket,
197                                               enum alloc_reserve reserve,
198                                               const struct bch_alloc_v4 *a,
199                                               struct bucket_alloc_state *s,
200                                               struct closure *cl)
201 {
202         struct open_bucket *ob;
203
204         if (unlikely(ca->buckets_nouse && test_bit(bucket, ca->buckets_nouse))) {
205                 s->skipped_nouse++;
206                 return NULL;
207         }
208
209         if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {
210                 s->skipped_open++;
211                 return NULL;
212         }
213
214         if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
215                         c->journal.flushed_seq_ondisk, ca->dev_idx, bucket)) {
216                 s->skipped_need_journal_commit++;
217                 return NULL;
218         }
219
220         if (bch2_bucket_nocow_is_locked(&c->nocow_locks, POS(ca->dev_idx, bucket))) {
221                 s->skipped_nocow++;
222                 return NULL;
223         }
224
225         spin_lock(&c->freelist_lock);
226
227         if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(reserve))) {
228                 if (cl)
229                         closure_wait(&c->open_buckets_wait, cl);
230
231                 if (!c->blocked_allocate_open_bucket)
232                         c->blocked_allocate_open_bucket = local_clock();
233
234                 spin_unlock(&c->freelist_lock);
235                 return ERR_PTR(-BCH_ERR_open_buckets_empty);
236         }
237
238         /* Recheck under lock: */
239         if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {
240                 spin_unlock(&c->freelist_lock);
241                 s->skipped_open++;
242                 return NULL;
243         }
244
245         ob = bch2_open_bucket_alloc(c);
246
247         spin_lock(&ob->lock);
248
249         ob->valid       = true;
250         ob->sectors_free = ca->mi.bucket_size;
251         ob->alloc_reserve = reserve;
252         ob->dev         = ca->dev_idx;
253         ob->gen         = a->gen;
254         ob->bucket      = bucket;
255         spin_unlock(&ob->lock);
256
257         ca->nr_open_buckets++;
258         bch2_open_bucket_hash_add(c, ob);
259
260         if (c->blocked_allocate_open_bucket) {
261                 bch2_time_stats_update(
262                         &c->times[BCH_TIME_blocked_allocate_open_bucket],
263                         c->blocked_allocate_open_bucket);
264                 c->blocked_allocate_open_bucket = 0;
265         }
266
267         if (c->blocked_allocate) {
268                 bch2_time_stats_update(
269                         &c->times[BCH_TIME_blocked_allocate],
270                         c->blocked_allocate);
271                 c->blocked_allocate = 0;
272         }
273
274         spin_unlock(&c->freelist_lock);
275
276         return ob;
277 }
278
279 static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bch_dev *ca,
280                                             enum alloc_reserve reserve, u64 free_entry,
281                                             struct bucket_alloc_state *s,
282                                             struct bkey_s_c freespace_k,
283                                             struct closure *cl)
284 {
285         struct bch_fs *c = trans->c;
286         struct btree_iter iter = { NULL };
287         struct bkey_s_c k;
288         struct open_bucket *ob;
289         struct bch_alloc_v4 a_convert;
290         const struct bch_alloc_v4 *a;
291         u64 b = free_entry & ~(~0ULL << 56);
292         unsigned genbits = free_entry >> 56;
293         struct printbuf buf = PRINTBUF;
294         int ret;
295
296         if (b < ca->mi.first_bucket || b >= ca->mi.nbuckets) {
297                 prt_printf(&buf, "freespace btree has bucket outside allowed range %u-%llu\n"
298                        "  freespace key ",
299                         ca->mi.first_bucket, ca->mi.nbuckets);
300                 bch2_bkey_val_to_text(&buf, c, freespace_k);
301                 bch2_trans_inconsistent(trans, "%s", buf.buf);
302                 ob = ERR_PTR(-EIO);
303                 goto err;
304         }
305
306         bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, POS(ca->dev_idx, b), BTREE_ITER_CACHED);
307         k = bch2_btree_iter_peek_slot(&iter);
308         ret = bkey_err(k);
309         if (ret) {
310                 ob = ERR_PTR(ret);
311                 goto err;
312         }
313
314         a = bch2_alloc_to_v4(k, &a_convert);
315
316         if (a->data_type != BCH_DATA_free) {
317                 if (!test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags)) {
318                         ob = NULL;
319                         goto err;
320                 }
321
322                 prt_printf(&buf, "non free bucket in freespace btree\n"
323                        "  freespace key ");
324                 bch2_bkey_val_to_text(&buf, c, freespace_k);
325                 prt_printf(&buf, "\n  ");
326                 bch2_bkey_val_to_text(&buf, c, k);
327                 bch2_trans_inconsistent(trans, "%s", buf.buf);
328                 ob = ERR_PTR(-EIO);
329                 goto err;
330         }
331
332         if (genbits != (alloc_freespace_genbits(*a) >> 56) &&
333             test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags)) {
334                 prt_printf(&buf, "bucket in freespace btree with wrong genbits (got %u should be %llu)\n"
335                        "  freespace key ",
336                        genbits, alloc_freespace_genbits(*a) >> 56);
337                 bch2_bkey_val_to_text(&buf, c, freespace_k);
338                 prt_printf(&buf, "\n  ");
339                 bch2_bkey_val_to_text(&buf, c, k);
340                 bch2_trans_inconsistent(trans, "%s", buf.buf);
341                 ob = ERR_PTR(-EIO);
342                 goto err;
343
344         }
345
346         if (!test_bit(BCH_FS_CHECK_BACKPOINTERS_DONE, &c->flags)) {
347                 struct bch_backpointer bp;
348                 u64 bp_offset = 0;
349
350                 ret = bch2_get_next_backpointer(trans, POS(ca->dev_idx, b), -1,
351                                                 &bp_offset, &bp,
352                                                 BTREE_ITER_NOPRESERVE);
353                 if (ret) {
354                         ob = ERR_PTR(ret);
355                         goto err;
356                 }
357
358                 if (bp_offset != U64_MAX) {
359                         /*
360                          * Bucket may have data in it - we don't call
361                          * bc2h_trans_inconnsistent() because fsck hasn't
362                          * finished yet
363                          */
364                         ob = NULL;
365                         goto err;
366                 }
367         }
368
369         ob = __try_alloc_bucket(c, ca, b, reserve, a, s, cl);
370         if (!ob)
371                 iter.path->preserve = false;
372 err:
373         set_btree_iter_dontneed(&iter);
374         bch2_trans_iter_exit(trans, &iter);
375         printbuf_exit(&buf);
376         return ob;
377 }
378
379 static struct open_bucket *try_alloc_partial_bucket(struct bch_fs *c, struct bch_dev *ca,
380                                                     enum alloc_reserve reserve)
381 {
382         struct open_bucket *ob;
383         int i;
384
385         spin_lock(&c->freelist_lock);
386
387         for (i = ca->open_buckets_partial_nr - 1; i >= 0; --i) {
388                 ob = c->open_buckets + ca->open_buckets_partial[i];
389
390                 if (reserve <= ob->alloc_reserve) {
391                         array_remove_item(ca->open_buckets_partial,
392                                           ca->open_buckets_partial_nr,
393                                           i);
394                         ob->on_partial_list = false;
395                         ob->alloc_reserve = reserve;
396                         spin_unlock(&c->freelist_lock);
397                         return ob;
398                 }
399         }
400
401         spin_unlock(&c->freelist_lock);
402         return NULL;
403 }
404
405 /*
406  * This path is for before the freespace btree is initialized:
407  *
408  * If ca->new_fs_bucket_idx is nonzero, we haven't yet marked superblock &
409  * journal buckets - journal buckets will be < ca->new_fs_bucket_idx
410  */
411 static noinline struct open_bucket *
412 bch2_bucket_alloc_early(struct btree_trans *trans,
413                         struct bch_dev *ca,
414                         enum alloc_reserve reserve,
415                         struct bucket_alloc_state *s,
416                         struct closure *cl)
417 {
418         struct btree_iter iter;
419         struct bkey_s_c k;
420         struct open_bucket *ob = NULL;
421         int ret;
422
423         s->cur_bucket = max_t(u64, s->cur_bucket, ca->mi.first_bucket);
424         s->cur_bucket = max_t(u64, s->cur_bucket, ca->new_fs_bucket_idx);
425
426         for_each_btree_key_norestart(trans, iter, BTREE_ID_alloc, POS(ca->dev_idx, s->cur_bucket),
427                            BTREE_ITER_SLOTS, k, ret) {
428                 struct bch_alloc_v4 a_convert;
429                 const struct bch_alloc_v4 *a;
430
431                 if (bkey_ge(k.k->p, POS(ca->dev_idx, ca->mi.nbuckets)))
432                         break;
433
434                 if (ca->new_fs_bucket_idx &&
435                     is_superblock_bucket(ca, k.k->p.offset))
436                         continue;
437
438                 a = bch2_alloc_to_v4(k, &a_convert);
439
440                 if (a->data_type != BCH_DATA_free)
441                         continue;
442
443                 s->buckets_seen++;
444
445                 ob = __try_alloc_bucket(trans->c, ca, k.k->p.offset, reserve, a, s, cl);
446                 if (ob)
447                         break;
448         }
449         bch2_trans_iter_exit(trans, &iter);
450
451         s->cur_bucket = iter.pos.offset;
452
453         return ob ?: ERR_PTR(ret ?: -BCH_ERR_no_buckets_found);
454 }
455
456 static struct open_bucket *bch2_bucket_alloc_freelist(struct btree_trans *trans,
457                                                    struct bch_dev *ca,
458                                                    enum alloc_reserve reserve,
459                                                    struct bucket_alloc_state *s,
460                                                    struct closure *cl)
461 {
462         struct btree_iter iter;
463         struct bkey_s_c k;
464         struct open_bucket *ob = NULL;
465         int ret;
466
467         BUG_ON(ca->new_fs_bucket_idx);
468
469         /*
470          * XXX:
471          * On transaction restart, we'd like to restart from the bucket we were
472          * at previously
473          */
474         for_each_btree_key_norestart(trans, iter, BTREE_ID_freespace,
475                                      POS(ca->dev_idx, s->cur_bucket), 0, k, ret) {
476                 if (k.k->p.inode != ca->dev_idx)
477                         break;
478
479                 for (s->cur_bucket = max(s->cur_bucket, bkey_start_offset(k.k));
480                      s->cur_bucket < k.k->p.offset;
481                      s->cur_bucket++) {
482                         ret = btree_trans_too_many_iters(trans);
483                         if (ret)
484                                 break;
485
486                         s->buckets_seen++;
487
488                         ob = try_alloc_bucket(trans, ca, reserve,
489                                               s->cur_bucket, s, k, cl);
490                         if (ob)
491                                 break;
492                 }
493
494                 if (ob || ret)
495                         break;
496         }
497         bch2_trans_iter_exit(trans, &iter);
498
499         return ob ?: ERR_PTR(ret);
500 }
501
502 /**
503  * bch_bucket_alloc - allocate a single bucket from a specific device
504  *
505  * Returns index of bucket on success, 0 on failure
506  */
507 static struct open_bucket *bch2_bucket_alloc_trans(struct btree_trans *trans,
508                                       struct bch_dev *ca,
509                                       enum alloc_reserve reserve,
510                                       bool may_alloc_partial,
511                                       struct closure *cl,
512                                       struct bch_dev_usage *usage)
513 {
514         struct bch_fs *c = trans->c;
515         struct open_bucket *ob = NULL;
516         bool freespace = READ_ONCE(ca->mi.freespace_initialized);
517         u64 start = freespace ? 0 : ca->bucket_alloc_trans_early_cursor;
518         u64 avail;
519         struct bucket_alloc_state s = { .cur_bucket = start };
520         bool waiting = false;
521 again:
522         bch2_dev_usage_read_fast(ca, usage);
523         avail = dev_buckets_free(ca, *usage, reserve);
524
525         if (usage->d[BCH_DATA_need_discard].buckets > avail)
526                 bch2_do_discards(c);
527
528         if (usage->d[BCH_DATA_need_gc_gens].buckets > avail)
529                 bch2_do_gc_gens(c);
530
531         if (should_invalidate_buckets(ca, *usage))
532                 bch2_do_invalidates(c);
533
534         if (!avail) {
535                 if (cl && !waiting) {
536                         closure_wait(&c->freelist_wait, cl);
537                         waiting = true;
538                         goto again;
539                 }
540
541                 if (!c->blocked_allocate)
542                         c->blocked_allocate = local_clock();
543
544                 ob = ERR_PTR(-BCH_ERR_freelist_empty);
545                 goto err;
546         }
547
548         if (waiting)
549                 closure_wake_up(&c->freelist_wait);
550
551         if (may_alloc_partial) {
552                 ob = try_alloc_partial_bucket(c, ca, reserve);
553                 if (ob)
554                         return ob;
555         }
556 alloc:
557         ob = likely(freespace)
558                 ? bch2_bucket_alloc_freelist(trans, ca, reserve, &s, cl)
559                 : bch2_bucket_alloc_early(trans, ca, reserve, &s, cl);
560
561         if (s.skipped_need_journal_commit * 2 > avail)
562                 bch2_journal_flush_async(&c->journal, NULL);
563
564         if (!ob && !freespace && start) {
565                 start = s.cur_bucket = 0;
566                 goto alloc;
567         }
568
569         if (!ob && freespace && !test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags)) {
570                 freespace = false;
571                 goto alloc;
572         }
573
574         if (!freespace)
575                 ca->bucket_alloc_trans_early_cursor = s.cur_bucket;
576 err:
577         if (!ob)
578                 ob = ERR_PTR(-BCH_ERR_no_buckets_found);
579
580         if (!IS_ERR(ob))
581                 trace_and_count(c, bucket_alloc, ca, bch2_alloc_reserves[reserve],
582                                 may_alloc_partial, ob->bucket);
583         else if (!bch2_err_matches(PTR_ERR(ob), BCH_ERR_transaction_restart))
584                 trace_and_count(c, bucket_alloc_fail,
585                                 ca, bch2_alloc_reserves[reserve],
586                                 usage->d[BCH_DATA_free].buckets,
587                                 avail,
588                                 bch2_copygc_wait_amount(c),
589                                 c->copygc_wait - atomic64_read(&c->io_clock[WRITE].now),
590                                 &s,
591                                 cl == NULL,
592                                 bch2_err_str(PTR_ERR(ob)));
593
594         return ob;
595 }
596
597 struct open_bucket *bch2_bucket_alloc(struct bch_fs *c, struct bch_dev *ca,
598                                       enum alloc_reserve reserve,
599                                       bool may_alloc_partial,
600                                       struct closure *cl)
601 {
602         struct bch_dev_usage usage;
603         struct open_bucket *ob;
604
605         bch2_trans_do(c, NULL, NULL, 0,
606                       PTR_ERR_OR_ZERO(ob = bch2_bucket_alloc_trans(&trans, ca, reserve,
607                                                         may_alloc_partial, cl, &usage)));
608         return ob;
609 }
610
611 static int __dev_stripe_cmp(struct dev_stripe_state *stripe,
612                             unsigned l, unsigned r)
613 {
614         return ((stripe->next_alloc[l] > stripe->next_alloc[r]) -
615                 (stripe->next_alloc[l] < stripe->next_alloc[r]));
616 }
617
618 #define dev_stripe_cmp(l, r) __dev_stripe_cmp(stripe, l, r)
619
620 struct dev_alloc_list bch2_dev_alloc_list(struct bch_fs *c,
621                                           struct dev_stripe_state *stripe,
622                                           struct bch_devs_mask *devs)
623 {
624         struct dev_alloc_list ret = { .nr = 0 };
625         unsigned i;
626
627         for_each_set_bit(i, devs->d, BCH_SB_MEMBERS_MAX)
628                 ret.devs[ret.nr++] = i;
629
630         bubble_sort(ret.devs, ret.nr, dev_stripe_cmp);
631         return ret;
632 }
633
634 static inline void bch2_dev_stripe_increment_inlined(struct bch_dev *ca,
635                                struct dev_stripe_state *stripe,
636                                struct bch_dev_usage *usage)
637 {
638         u64 *v = stripe->next_alloc + ca->dev_idx;
639         u64 free_space = dev_buckets_available(ca, RESERVE_none);
640         u64 free_space_inv = free_space
641                 ? div64_u64(1ULL << 48, free_space)
642                 : 1ULL << 48;
643         u64 scale = *v / 4;
644
645         if (*v + free_space_inv >= *v)
646                 *v += free_space_inv;
647         else
648                 *v = U64_MAX;
649
650         for (v = stripe->next_alloc;
651              v < stripe->next_alloc + ARRAY_SIZE(stripe->next_alloc); v++)
652                 *v = *v < scale ? 0 : *v - scale;
653 }
654
655 void bch2_dev_stripe_increment(struct bch_dev *ca,
656                                struct dev_stripe_state *stripe)
657 {
658         struct bch_dev_usage usage;
659
660         bch2_dev_usage_read_fast(ca, &usage);
661         bch2_dev_stripe_increment_inlined(ca, stripe, &usage);
662 }
663
664 #define BUCKET_MAY_ALLOC_PARTIAL        (1 << 0)
665 #define BUCKET_ALLOC_USE_DURABILITY     (1 << 1)
666
667 static void add_new_bucket(struct bch_fs *c,
668                            struct open_buckets *ptrs,
669                            struct bch_devs_mask *devs_may_alloc,
670                            unsigned *nr_effective,
671                            bool *have_cache,
672                            unsigned flags,
673                            struct open_bucket *ob)
674 {
675         unsigned durability =
676                 bch_dev_bkey_exists(c, ob->dev)->mi.durability;
677
678         __clear_bit(ob->dev, devs_may_alloc->d);
679         *nr_effective   += (flags & BUCKET_ALLOC_USE_DURABILITY)
680                 ? durability : 1;
681         *have_cache     |= !durability;
682
683         ob_push(c, ptrs, ob);
684 }
685
686 static int bch2_bucket_alloc_set_trans(struct btree_trans *trans,
687                       struct open_buckets *ptrs,
688                       struct dev_stripe_state *stripe,
689                       struct bch_devs_mask *devs_may_alloc,
690                       unsigned nr_replicas,
691                       unsigned *nr_effective,
692                       bool *have_cache,
693                       enum alloc_reserve reserve,
694                       unsigned flags,
695                       struct closure *cl)
696 {
697         struct bch_fs *c = trans->c;
698         struct dev_alloc_list devs_sorted =
699                 bch2_dev_alloc_list(c, stripe, devs_may_alloc);
700         unsigned dev;
701         struct bch_dev *ca;
702         int ret = -BCH_ERR_insufficient_devices;
703         unsigned i;
704
705         BUG_ON(*nr_effective >= nr_replicas);
706
707         for (i = 0; i < devs_sorted.nr; i++) {
708                 struct bch_dev_usage usage;
709                 struct open_bucket *ob;
710
711                 dev = devs_sorted.devs[i];
712
713                 rcu_read_lock();
714                 ca = rcu_dereference(c->devs[dev]);
715                 if (ca)
716                         percpu_ref_get(&ca->ref);
717                 rcu_read_unlock();
718
719                 if (!ca)
720                         continue;
721
722                 if (!ca->mi.durability && *have_cache) {
723                         percpu_ref_put(&ca->ref);
724                         continue;
725                 }
726
727                 ob = bch2_bucket_alloc_trans(trans, ca, reserve,
728                                 flags & BUCKET_MAY_ALLOC_PARTIAL, cl, &usage);
729                 if (!IS_ERR(ob))
730                         bch2_dev_stripe_increment_inlined(ca, stripe, &usage);
731                 percpu_ref_put(&ca->ref);
732
733                 if (IS_ERR(ob)) {
734                         ret = PTR_ERR(ob);
735                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart) || cl)
736                                 break;
737                         continue;
738                 }
739
740                 add_new_bucket(c, ptrs, devs_may_alloc,
741                                nr_effective, have_cache, flags, ob);
742
743                 if (*nr_effective >= nr_replicas) {
744                         ret = 0;
745                         break;
746                 }
747         }
748
749         return ret;
750 }
751
752 int bch2_bucket_alloc_set(struct bch_fs *c,
753                       struct open_buckets *ptrs,
754                       struct dev_stripe_state *stripe,
755                       struct bch_devs_mask *devs_may_alloc,
756                       unsigned nr_replicas,
757                       unsigned *nr_effective,
758                       bool *have_cache,
759                       enum alloc_reserve reserve,
760                       unsigned flags,
761                       struct closure *cl)
762 {
763         return bch2_trans_do(c, NULL, NULL, 0,
764                       bch2_bucket_alloc_set_trans(&trans, ptrs, stripe,
765                                               devs_may_alloc, nr_replicas,
766                                               nr_effective, have_cache, reserve,
767                                               flags, cl));
768 }
769
770 /* Allocate from stripes: */
771
772 /*
773  * if we can't allocate a new stripe because there are already too many
774  * partially filled stripes, force allocating from an existing stripe even when
775  * it's to a device we don't want:
776  */
777
778 static int bucket_alloc_from_stripe(struct bch_fs *c,
779                          struct open_buckets *ptrs,
780                          struct write_point *wp,
781                          struct bch_devs_mask *devs_may_alloc,
782                          u16 target,
783                          unsigned erasure_code,
784                          unsigned nr_replicas,
785                          unsigned *nr_effective,
786                          bool *have_cache,
787                          unsigned flags,
788                          struct closure *cl)
789 {
790         struct dev_alloc_list devs_sorted;
791         struct ec_stripe_head *h;
792         struct open_bucket *ob;
793         struct bch_dev *ca;
794         unsigned i, ec_idx;
795
796         if (!erasure_code)
797                 return 0;
798
799         if (nr_replicas < 2)
800                 return 0;
801
802         if (ec_open_bucket(c, ptrs))
803                 return 0;
804
805         h = bch2_ec_stripe_head_get(c, target, 0, nr_replicas - 1,
806                                     wp == &c->copygc_write_point,
807                                     cl);
808         if (IS_ERR(h))
809                 return -PTR_ERR(h);
810         if (!h)
811                 return 0;
812
813         devs_sorted = bch2_dev_alloc_list(c, &wp->stripe, devs_may_alloc);
814
815         for (i = 0; i < devs_sorted.nr; i++)
816                 for (ec_idx = 0; ec_idx < h->s->nr_data; ec_idx++) {
817                         if (!h->s->blocks[ec_idx])
818                                 continue;
819
820                         ob = c->open_buckets + h->s->blocks[ec_idx];
821                         if (ob->dev == devs_sorted.devs[i] &&
822                             !test_and_set_bit(ec_idx, h->s->blocks_allocated))
823                                 goto got_bucket;
824                 }
825         goto out_put_head;
826 got_bucket:
827         ca = bch_dev_bkey_exists(c, ob->dev);
828
829         ob->ec_idx      = ec_idx;
830         ob->ec          = h->s;
831
832         add_new_bucket(c, ptrs, devs_may_alloc,
833                        nr_effective, have_cache, flags, ob);
834         atomic_inc(&h->s->pin);
835 out_put_head:
836         bch2_ec_stripe_head_put(c, h);
837         return 0;
838 }
839
840 /* Sector allocator */
841
842 static void get_buckets_from_writepoint(struct bch_fs *c,
843                                         struct open_buckets *ptrs,
844                                         struct write_point *wp,
845                                         struct bch_devs_mask *devs_may_alloc,
846                                         unsigned nr_replicas,
847                                         unsigned *nr_effective,
848                                         bool *have_cache,
849                                         unsigned flags,
850                                         bool need_ec)
851 {
852         struct open_buckets ptrs_skip = { .nr = 0 };
853         struct open_bucket *ob;
854         unsigned i;
855
856         open_bucket_for_each(c, &wp->ptrs, ob, i) {
857                 struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
858
859                 if (*nr_effective < nr_replicas &&
860                     test_bit(ob->dev, devs_may_alloc->d) &&
861                     (ca->mi.durability ||
862                      (wp->data_type == BCH_DATA_user && !*have_cache)) &&
863                     (ob->ec || !need_ec)) {
864                         add_new_bucket(c, ptrs, devs_may_alloc,
865                                        nr_effective, have_cache,
866                                        flags, ob);
867                 } else {
868                         ob_push(c, &ptrs_skip, ob);
869                 }
870         }
871         wp->ptrs = ptrs_skip;
872 }
873
874 static int open_bucket_add_buckets(struct btree_trans *trans,
875                         struct open_buckets *ptrs,
876                         struct write_point *wp,
877                         struct bch_devs_list *devs_have,
878                         u16 target,
879                         unsigned erasure_code,
880                         unsigned nr_replicas,
881                         unsigned *nr_effective,
882                         bool *have_cache,
883                         enum alloc_reserve reserve,
884                         unsigned flags,
885                         struct closure *_cl)
886 {
887         struct bch_fs *c = trans->c;
888         struct bch_devs_mask devs;
889         struct open_bucket *ob;
890         struct closure *cl = NULL;
891         int ret;
892         unsigned i;
893
894         rcu_read_lock();
895         devs = target_rw_devs(c, wp->data_type, target);
896         rcu_read_unlock();
897
898         /* Don't allocate from devices we already have pointers to: */
899         for (i = 0; i < devs_have->nr; i++)
900                 __clear_bit(devs_have->devs[i], devs.d);
901
902         open_bucket_for_each(c, ptrs, ob, i)
903                 __clear_bit(ob->dev, devs.d);
904
905         if (erasure_code) {
906                 if (!ec_open_bucket(c, ptrs)) {
907                         get_buckets_from_writepoint(c, ptrs, wp, &devs,
908                                                     nr_replicas, nr_effective,
909                                                     have_cache, flags, true);
910                         if (*nr_effective >= nr_replicas)
911                                 return 0;
912                 }
913
914                 if (!ec_open_bucket(c, ptrs)) {
915                         ret = bucket_alloc_from_stripe(c, ptrs, wp, &devs,
916                                                  target, erasure_code,
917                                                  nr_replicas, nr_effective,
918                                                  have_cache, flags, _cl);
919                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
920                             bch2_err_matches(ret, BCH_ERR_freelist_empty) ||
921                             bch2_err_matches(ret, BCH_ERR_open_buckets_empty))
922                                 return ret;
923                         if (*nr_effective >= nr_replicas)
924                                 return 0;
925                 }
926         }
927
928         get_buckets_from_writepoint(c, ptrs, wp, &devs,
929                                     nr_replicas, nr_effective,
930                                     have_cache, flags, false);
931         if (*nr_effective >= nr_replicas)
932                 return 0;
933
934 retry_blocking:
935         /*
936          * Try nonblocking first, so that if one device is full we'll try from
937          * other devices:
938          */
939         ret = bch2_bucket_alloc_set_trans(trans, ptrs, &wp->stripe, &devs,
940                                 nr_replicas, nr_effective, have_cache,
941                                 reserve, flags, cl);
942         if (ret &&
943             !bch2_err_matches(ret, BCH_ERR_transaction_restart) &&
944             !bch2_err_matches(ret, BCH_ERR_insufficient_devices) &&
945             !cl && _cl) {
946                 cl = _cl;
947                 goto retry_blocking;
948         }
949
950         return ret;
951 }
952
953 void bch2_open_buckets_stop_dev(struct bch_fs *c, struct bch_dev *ca,
954                                 struct open_buckets *obs)
955 {
956         struct open_buckets ptrs = { .nr = 0 };
957         struct open_bucket *ob, *ob2;
958         unsigned i, j;
959
960         open_bucket_for_each(c, obs, ob, i) {
961                 bool drop = !ca || ob->dev == ca->dev_idx;
962
963                 if (!drop && ob->ec) {
964                         mutex_lock(&ob->ec->lock);
965                         for (j = 0; j < ob->ec->new_stripe.key.v.nr_blocks; j++) {
966                                 if (!ob->ec->blocks[j])
967                                         continue;
968
969                                 ob2 = c->open_buckets + ob->ec->blocks[j];
970                                 drop |= ob2->dev == ca->dev_idx;
971                         }
972                         mutex_unlock(&ob->ec->lock);
973                 }
974
975                 if (drop)
976                         bch2_open_bucket_put(c, ob);
977                 else
978                         ob_push(c, &ptrs, ob);
979         }
980
981         *obs = ptrs;
982 }
983
984 void bch2_writepoint_stop(struct bch_fs *c, struct bch_dev *ca,
985                           struct write_point *wp)
986 {
987         mutex_lock(&wp->lock);
988         bch2_open_buckets_stop_dev(c, ca, &wp->ptrs);
989         mutex_unlock(&wp->lock);
990 }
991
992 static inline struct hlist_head *writepoint_hash(struct bch_fs *c,
993                                                  unsigned long write_point)
994 {
995         unsigned hash =
996                 hash_long(write_point, ilog2(ARRAY_SIZE(c->write_points_hash)));
997
998         return &c->write_points_hash[hash];
999 }
1000
1001 static struct write_point *__writepoint_find(struct hlist_head *head,
1002                                              unsigned long write_point)
1003 {
1004         struct write_point *wp;
1005
1006         rcu_read_lock();
1007         hlist_for_each_entry_rcu(wp, head, node)
1008                 if (wp->write_point == write_point)
1009                         goto out;
1010         wp = NULL;
1011 out:
1012         rcu_read_unlock();
1013         return wp;
1014 }
1015
1016 static inline bool too_many_writepoints(struct bch_fs *c, unsigned factor)
1017 {
1018         u64 stranded    = c->write_points_nr * c->bucket_size_max;
1019         u64 free        = bch2_fs_usage_read_short(c).free;
1020
1021         return stranded * factor > free;
1022 }
1023
1024 static bool try_increase_writepoints(struct bch_fs *c)
1025 {
1026         struct write_point *wp;
1027
1028         if (c->write_points_nr == ARRAY_SIZE(c->write_points) ||
1029             too_many_writepoints(c, 32))
1030                 return false;
1031
1032         wp = c->write_points + c->write_points_nr++;
1033         hlist_add_head_rcu(&wp->node, writepoint_hash(c, wp->write_point));
1034         return true;
1035 }
1036
1037 static bool try_decrease_writepoints(struct bch_fs *c,
1038                                      unsigned old_nr)
1039 {
1040         struct write_point *wp;
1041
1042         mutex_lock(&c->write_points_hash_lock);
1043         if (c->write_points_nr < old_nr) {
1044                 mutex_unlock(&c->write_points_hash_lock);
1045                 return true;
1046         }
1047
1048         if (c->write_points_nr == 1 ||
1049             !too_many_writepoints(c, 8)) {
1050                 mutex_unlock(&c->write_points_hash_lock);
1051                 return false;
1052         }
1053
1054         wp = c->write_points + --c->write_points_nr;
1055
1056         hlist_del_rcu(&wp->node);
1057         mutex_unlock(&c->write_points_hash_lock);
1058
1059         bch2_writepoint_stop(c, NULL, wp);
1060         return true;
1061 }
1062
1063 static void bch2_trans_mutex_lock(struct btree_trans *trans,
1064                                   struct mutex *lock)
1065 {
1066         if (!mutex_trylock(lock)) {
1067                 bch2_trans_unlock(trans);
1068                 mutex_lock(lock);
1069         }
1070 }
1071
1072 static struct write_point *writepoint_find(struct btree_trans *trans,
1073                                            unsigned long write_point)
1074 {
1075         struct bch_fs *c = trans->c;
1076         struct write_point *wp, *oldest;
1077         struct hlist_head *head;
1078
1079         if (!(write_point & 1UL)) {
1080                 wp = (struct write_point *) write_point;
1081                 bch2_trans_mutex_lock(trans, &wp->lock);
1082                 return wp;
1083         }
1084
1085         head = writepoint_hash(c, write_point);
1086 restart_find:
1087         wp = __writepoint_find(head, write_point);
1088         if (wp) {
1089 lock_wp:
1090                 bch2_trans_mutex_lock(trans, &wp->lock);
1091                 if (wp->write_point == write_point)
1092                         goto out;
1093                 mutex_unlock(&wp->lock);
1094                 goto restart_find;
1095         }
1096 restart_find_oldest:
1097         oldest = NULL;
1098         for (wp = c->write_points;
1099              wp < c->write_points + c->write_points_nr; wp++)
1100                 if (!oldest || time_before64(wp->last_used, oldest->last_used))
1101                         oldest = wp;
1102
1103         bch2_trans_mutex_lock(trans, &oldest->lock);
1104         bch2_trans_mutex_lock(trans, &c->write_points_hash_lock);
1105         if (oldest >= c->write_points + c->write_points_nr ||
1106             try_increase_writepoints(c)) {
1107                 mutex_unlock(&c->write_points_hash_lock);
1108                 mutex_unlock(&oldest->lock);
1109                 goto restart_find_oldest;
1110         }
1111
1112         wp = __writepoint_find(head, write_point);
1113         if (wp && wp != oldest) {
1114                 mutex_unlock(&c->write_points_hash_lock);
1115                 mutex_unlock(&oldest->lock);
1116                 goto lock_wp;
1117         }
1118
1119         wp = oldest;
1120         hlist_del_rcu(&wp->node);
1121         wp->write_point = write_point;
1122         hlist_add_head_rcu(&wp->node, head);
1123         mutex_unlock(&c->write_points_hash_lock);
1124 out:
1125         wp->last_used = local_clock();
1126         return wp;
1127 }
1128
1129 /*
1130  * Get us an open_bucket we can allocate from, return with it locked:
1131  */
1132 int bch2_alloc_sectors_start_trans(struct btree_trans *trans,
1133                                    unsigned target,
1134                                    unsigned erasure_code,
1135                                    struct write_point_specifier write_point,
1136                                    struct bch_devs_list *devs_have,
1137                                    unsigned nr_replicas,
1138                                    unsigned nr_replicas_required,
1139                                    enum alloc_reserve reserve,
1140                                    unsigned flags,
1141                                    struct closure *cl,
1142                                    struct write_point **wp_ret)
1143 {
1144         struct bch_fs *c = trans->c;
1145         struct write_point *wp;
1146         struct open_bucket *ob;
1147         struct open_buckets ptrs;
1148         unsigned nr_effective, write_points_nr;
1149         unsigned ob_flags = 0;
1150         bool have_cache;
1151         int ret;
1152         int i;
1153
1154         if (!(flags & BCH_WRITE_ONLY_SPECIFIED_DEVS))
1155                 ob_flags |= BUCKET_ALLOC_USE_DURABILITY;
1156
1157         BUG_ON(!nr_replicas || !nr_replicas_required);
1158 retry:
1159         ptrs.nr         = 0;
1160         nr_effective    = 0;
1161         write_points_nr = c->write_points_nr;
1162         have_cache      = false;
1163
1164         *wp_ret = wp = writepoint_find(trans, write_point.v);
1165
1166         if (wp->data_type == BCH_DATA_user)
1167                 ob_flags |= BUCKET_MAY_ALLOC_PARTIAL;
1168
1169         /* metadata may not allocate on cache devices: */
1170         if (wp->data_type != BCH_DATA_user)
1171                 have_cache = true;
1172
1173         if (!target || (flags & BCH_WRITE_ONLY_SPECIFIED_DEVS)) {
1174                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1175                                               target, erasure_code,
1176                                               nr_replicas, &nr_effective,
1177                                               &have_cache, reserve,
1178                                               ob_flags, cl);
1179         } else {
1180                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1181                                               target, erasure_code,
1182                                               nr_replicas, &nr_effective,
1183                                               &have_cache, reserve,
1184                                               ob_flags, NULL);
1185                 if (!ret ||
1186                     bch2_err_matches(ret, BCH_ERR_transaction_restart))
1187                         goto alloc_done;
1188
1189                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1190                                               0, erasure_code,
1191                                               nr_replicas, &nr_effective,
1192                                               &have_cache, reserve,
1193                                               ob_flags, cl);
1194         }
1195 alloc_done:
1196         BUG_ON(!ret && nr_effective < nr_replicas);
1197
1198         if (erasure_code && !ec_open_bucket(c, &ptrs))
1199                 pr_debug("failed to get ec bucket: ret %u", ret);
1200
1201         if (ret == -BCH_ERR_insufficient_devices &&
1202             nr_effective >= nr_replicas_required)
1203                 ret = 0;
1204
1205         if (ret)
1206                 goto err;
1207
1208         /* Free buckets we didn't use: */
1209         open_bucket_for_each(c, &wp->ptrs, ob, i)
1210                 open_bucket_free_unused(c, wp, ob);
1211
1212         wp->ptrs = ptrs;
1213
1214         wp->sectors_free = UINT_MAX;
1215
1216         open_bucket_for_each(c, &wp->ptrs, ob, i)
1217                 wp->sectors_free = min(wp->sectors_free, ob->sectors_free);
1218
1219         BUG_ON(!wp->sectors_free || wp->sectors_free == UINT_MAX);
1220
1221         return 0;
1222 err:
1223         open_bucket_for_each(c, &wp->ptrs, ob, i)
1224                 if (ptrs.nr < ARRAY_SIZE(ptrs.v))
1225                         ob_push(c, &ptrs, ob);
1226                 else
1227                         open_bucket_free_unused(c, wp, ob);
1228         wp->ptrs = ptrs;
1229
1230         mutex_unlock(&wp->lock);
1231
1232         if (bch2_err_matches(ret, BCH_ERR_freelist_empty) &&
1233             try_decrease_writepoints(c, write_points_nr))
1234                 goto retry;
1235
1236         if (bch2_err_matches(ret, BCH_ERR_open_buckets_empty) ||
1237             bch2_err_matches(ret, BCH_ERR_freelist_empty))
1238                 return cl
1239                         ? -BCH_ERR_bucket_alloc_blocked
1240                         : -BCH_ERR_ENOSPC_bucket_alloc;
1241
1242         return ret;
1243 }
1244
1245 struct bch_extent_ptr bch2_ob_ptr(struct bch_fs *c, struct open_bucket *ob)
1246 {
1247         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
1248
1249         return (struct bch_extent_ptr) {
1250                 .type   = 1 << BCH_EXTENT_ENTRY_ptr,
1251                 .gen    = ob->gen,
1252                 .dev    = ob->dev,
1253                 .offset = bucket_to_sector(ca, ob->bucket) +
1254                         ca->mi.bucket_size -
1255                         ob->sectors_free,
1256         };
1257 }
1258
1259 void bch2_alloc_sectors_append_ptrs(struct bch_fs *c, struct write_point *wp,
1260                                     struct bkey_i *k, unsigned sectors,
1261                                     bool cached)
1262 {
1263         bch2_alloc_sectors_append_ptrs_inlined(c, wp, k, sectors, cached);
1264 }
1265
1266 /*
1267  * Append pointers to the space we just allocated to @k, and mark @sectors space
1268  * as allocated out of @ob
1269  */
1270 void bch2_alloc_sectors_done(struct bch_fs *c, struct write_point *wp)
1271 {
1272         bch2_alloc_sectors_done_inlined(c, wp);
1273 }
1274
1275 static inline void writepoint_init(struct write_point *wp,
1276                                    enum bch_data_type type)
1277 {
1278         mutex_init(&wp->lock);
1279         wp->data_type = type;
1280
1281         INIT_WORK(&wp->index_update_work, bch2_write_point_do_index_updates);
1282         INIT_LIST_HEAD(&wp->writes);
1283         spin_lock_init(&wp->writes_lock);
1284 }
1285
1286 void bch2_fs_allocator_foreground_init(struct bch_fs *c)
1287 {
1288         struct open_bucket *ob;
1289         struct write_point *wp;
1290
1291         mutex_init(&c->write_points_hash_lock);
1292         c->write_points_nr = ARRAY_SIZE(c->write_points);
1293
1294         /* open bucket 0 is a sentinal NULL: */
1295         spin_lock_init(&c->open_buckets[0].lock);
1296
1297         for (ob = c->open_buckets + 1;
1298              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); ob++) {
1299                 spin_lock_init(&ob->lock);
1300                 c->open_buckets_nr_free++;
1301
1302                 ob->freelist = c->open_buckets_freelist;
1303                 c->open_buckets_freelist = ob - c->open_buckets;
1304         }
1305
1306         writepoint_init(&c->btree_write_point,          BCH_DATA_btree);
1307         writepoint_init(&c->rebalance_write_point,      BCH_DATA_user);
1308         writepoint_init(&c->copygc_write_point,         BCH_DATA_user);
1309
1310         for (wp = c->write_points;
1311              wp < c->write_points + c->write_points_nr; wp++) {
1312                 writepoint_init(wp, BCH_DATA_user);
1313
1314                 wp->last_used   = local_clock();
1315                 wp->write_point = (unsigned long) wp;
1316                 hlist_add_head_rcu(&wp->node,
1317                                    writepoint_hash(c, wp->write_point));
1318         }
1319 }
1320
1321 void bch2_open_buckets_to_text(struct printbuf *out, struct bch_fs *c)
1322 {
1323         struct open_bucket *ob;
1324
1325         for (ob = c->open_buckets;
1326              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets);
1327              ob++) {
1328                 spin_lock(&ob->lock);
1329                 if (ob->valid && !ob->on_partial_list) {
1330                         prt_printf(out, "%zu ref %u type %s %u:%llu:%u\n",
1331                                ob - c->open_buckets,
1332                                atomic_read(&ob->pin),
1333                                bch2_data_types[ob->data_type],
1334                                ob->dev, ob->bucket, ob->gen);
1335                 }
1336                 spin_unlock(&ob->lock);
1337         }
1338 }