git.sesse.net Git - bcachefs-tools-debian/blob - 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
  32 #include <linux/math64.h>
  33 #include <linux/rculist.h>
  34 #include <linux/rcupdate.h>
  35 #include <trace/events/bcachefs.h>
  36
  37 const char * const bch2_alloc_reserves[] = {
  38 #define x(t) #t,
  39         BCH_ALLOC_RESERVES()
  40 #undef x
  41         NULL
  42 };
  43
  44 /*
  45  * Open buckets represent a bucket that's currently being allocated from.  They
  46  * serve two purposes:
  47  *
  48  *  - They track buckets that have been partially allocated, allowing for
  49  *    sub-bucket sized allocations - they're used by the sector allocator below
  50  *
  51  *  - They provide a reference to the buckets they own that mark and sweep GC
  52  *    can find, until the new allocation has a pointer to it inserted into the
  53  *    btree
  54  *
  55  * When allocating some space with the sector allocator, the allocation comes
  56  * with a reference to an open bucket - the caller is required to put that
  57  * reference _after_ doing the index update that makes its allocation reachable.
  58  */
  59
  60 static void bch2_open_bucket_hash_add(struct bch_fs *c, struct open_bucket *ob)
  61 {
  62         open_bucket_idx_t idx = ob - c->open_buckets;
  63         open_bucket_idx_t *slot = open_bucket_hashslot(c, ob->dev, ob->bucket);
  64
  65         ob->hash = *slot;
  66         *slot = idx;
  67 }
  68
  69 static void bch2_open_bucket_hash_remove(struct bch_fs *c, struct open_bucket *ob)
  70 {
  71         open_bucket_idx_t idx = ob - c->open_buckets;
  72         open_bucket_idx_t *slot = open_bucket_hashslot(c, ob->dev, ob->bucket);
  73
  74         while (*slot != idx) {
  75                 BUG_ON(!*slot);
  76                 slot = &c->open_buckets[*slot].hash;
  77         }
  78
  79         *slot = ob->hash;
  80         ob->hash = 0;
  81 }
  82
  83 void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
  84 {
  85         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
  86
  87         if (ob->ec) {
  88                 bch2_ec_bucket_written(c, ob);
  89                 return;
  90         }
  91
  92         percpu_down_read(&c->mark_lock);
  93         spin_lock(&ob->lock);
  94
  95         ob->valid = false;
  96         ob->data_type = 0;
  97
  98         spin_unlock(&ob->lock);
  99         percpu_up_read(&c->mark_lock);
 100
 101         spin_lock(&c->freelist_lock);
 102         bch2_open_bucket_hash_remove(c, ob);
 103
 104         ob->freelist = c->open_buckets_freelist;
 105         c->open_buckets_freelist = ob - c->open_buckets;
 106
 107         c->open_buckets_nr_free++;
 108         ca->nr_open_buckets--;
 109         spin_unlock(&c->freelist_lock);
 110
 111         closure_wake_up(&c->open_buckets_wait);
 112 }
 113
 114 void bch2_open_bucket_write_error(struct bch_fs *c,
 115                                   struct open_buckets *obs,
 116                                   unsigned dev)
 117 {
 118         struct open_bucket *ob;
 119         unsigned i;
 120
 121         open_bucket_for_each(c, obs, ob, i)
 122                 if (ob->dev == dev && ob->ec)
 123                         bch2_ec_bucket_cancel(c, ob);
 124 }
 125
 126 static struct open_bucket *bch2_open_bucket_alloc(struct bch_fs *c)
 127 {
 128         struct open_bucket *ob;
 129
 130         BUG_ON(!c->open_buckets_freelist || !c->open_buckets_nr_free);
 131
 132         ob = c->open_buckets + c->open_buckets_freelist;
 133         c->open_buckets_freelist = ob->freelist;
 134         atomic_set(&ob->pin, 1);
 135         ob->data_type = 0;
 136
 137         c->open_buckets_nr_free--;
 138         return ob;
 139 }
 140
 141 static void open_bucket_free_unused(struct bch_fs *c,
 142                                     struct write_point *wp,
 143                                     struct open_bucket *ob)
 144 {
 145         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
 146         bool may_realloc = wp->data_type == BCH_DATA_user;
 147
 148         BUG_ON(ca->open_buckets_partial_nr >
 149                ARRAY_SIZE(ca->open_buckets_partial));
 150
 151         if (ca->open_buckets_partial_nr <
 152             ARRAY_SIZE(ca->open_buckets_partial) &&
 153             may_realloc) {
 154                 spin_lock(&c->freelist_lock);
 155                 ob->on_partial_list = true;
 156                 ca->open_buckets_partial[ca->open_buckets_partial_nr++] =
 157                         ob - c->open_buckets;
 158                 spin_unlock(&c->freelist_lock);
 159
 160                 closure_wake_up(&c->open_buckets_wait);
 161                 closure_wake_up(&c->freelist_wait);
 162         } else {
 163                 bch2_open_bucket_put(c, ob);
 164         }
 165 }
 166
 167 /* _only_ for allocating the journal on a new device: */
 168 long bch2_bucket_alloc_new_fs(struct bch_dev *ca)
 169 {
 170         while (ca->new_fs_bucket_idx < ca->mi.nbuckets) {
 171                 u64 b = ca->new_fs_bucket_idx++;
 172
 173                 if (!is_superblock_bucket(ca, b) &&
 174                     (!ca->buckets_nouse || !test_bit(b, ca->buckets_nouse)))
 175                         return b;
 176         }
 177
 178         return -1;
 179 }
 180
 181 static inline unsigned open_buckets_reserved(enum alloc_reserve reserve)
 182 {
 183         switch (reserve) {
 184         case RESERVE_btree:
 185         case RESERVE_btree_movinggc:
 186                 return 0;
 187         case RESERVE_movinggc:
 188                 return OPEN_BUCKETS_COUNT / 4;
 189         default:
 190                 return OPEN_BUCKETS_COUNT / 2;
 191         }
 192 }
 193
 194 static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *ca,
 195                                               u64 bucket,
 196                                               enum alloc_reserve reserve,
 197                                               struct bch_alloc_v4 *a,
 198                                               struct bucket_alloc_state *s,
 199                                               struct closure *cl)
 200 {
 201         struct open_bucket *ob;
 202
 203         if (unlikely(ca->buckets_nouse && test_bit(bucket, ca->buckets_nouse))) {
 204                 s->skipped_nouse++;
 205                 return NULL;
 206         }
 207
 208         if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {
 209                 s->skipped_open++;
 210                 return NULL;
 211         }
 212
 213         if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
 214                         c->journal.flushed_seq_ondisk, ca->dev_idx, bucket)) {
 215                 s->skipped_need_journal_commit++;
 216                 return NULL;
 217         }
 218
 219         if (bch2_bucket_nocow_is_locked(&c->nocow_locks, POS(ca->dev_idx, bucket))) {
 220                 s->skipped_nocow++;
 221                 return NULL;
 222         }
 223
 224         spin_lock(&c->freelist_lock);
 225
 226         if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(reserve))) {
 227                 if (cl)
 228                         closure_wait(&c->open_buckets_wait, cl);
 229
 230                 if (!c->blocked_allocate_open_bucket)
 231                         c->blocked_allocate_open_bucket = local_clock();
 232
 233                 spin_unlock(&c->freelist_lock);
 234                 return ERR_PTR(-BCH_ERR_open_buckets_empty);
 235         }
 236
 237         /* Recheck under lock: */
 238         if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {
 239                 spin_unlock(&c->freelist_lock);
 240                 s->skipped_open++;
 241                 return NULL;
 242         }
 243
 244         ob = bch2_open_bucket_alloc(c);
 245
 246         spin_lock(&ob->lock);
 247
 248         ob->valid       = true;
 249         ob->sectors_free = ca->mi.bucket_size;
 250         ob->alloc_reserve = reserve;
 251         ob->dev         = ca->dev_idx;
 252         ob->gen         = a->gen;
 253         ob->bucket      = bucket;
 254         spin_unlock(&ob->lock);
 255
 256         ca->nr_open_buckets++;
 257         bch2_open_bucket_hash_add(c, ob);
 258
 259         if (c->blocked_allocate_open_bucket) {
 260                 bch2_time_stats_update(
 261                         &c->times[BCH_TIME_blocked_allocate_open_bucket],
 262                         c->blocked_allocate_open_bucket);
 263                 c->blocked_allocate_open_bucket = 0;
 264         }
 265
 266         if (c->blocked_allocate) {
 267                 bch2_time_stats_update(
 268                         &c->times[BCH_TIME_blocked_allocate],
 269                         c->blocked_allocate);
 270                 c->blocked_allocate = 0;
 271         }
 272
 273         spin_unlock(&c->freelist_lock);
 274
 275         return ob;
 276 }
 277
 278 static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bch_dev *ca,
 279                                             enum alloc_reserve reserve, u64 free_entry,
 280                                             struct bucket_alloc_state *s,
 281                                             struct bkey_s_c freespace_k,
 282                                             struct closure *cl)
 283 {
 284         struct bch_fs *c = trans->c;
 285         struct btree_iter iter = { NULL };
 286         struct bkey_s_c k;
 287         struct open_bucket *ob;
 288         struct bch_alloc_v4 a;
 289         u64 b = free_entry & ~(~0ULL << 56);
 290         unsigned genbits = free_entry >> 56;
 291         struct printbuf buf = PRINTBUF;
 292         int ret;
 293
 294         if (b < ca->mi.first_bucket || b >= ca->mi.nbuckets) {
 295                 prt_printf(&buf, "freespace btree has bucket outside allowed range %u-%llu\n"
 296                        "  freespace key ",
 297                         ca->mi.first_bucket, ca->mi.nbuckets);
 298                 bch2_bkey_val_to_text(&buf, c, freespace_k);
 299                 bch2_trans_inconsistent(trans, "%s", buf.buf);
 300                 ob = ERR_PTR(-EIO);
 301                 goto err;
 302         }
 303
 304         bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, POS(ca->dev_idx, b), BTREE_ITER_CACHED);
 305         k = bch2_btree_iter_peek_slot(&iter);
 306         ret = bkey_err(k);
 307         if (ret) {
 308                 ob = ERR_PTR(ret);
 309                 goto err;
 310         }
 311
 312         bch2_alloc_to_v4(k, &a);
 313
 314         if (genbits != (alloc_freespace_genbits(a) >> 56)) {
 315                 prt_printf(&buf, "bucket in freespace btree with wrong genbits (got %u should be %llu)\n"
 316                        "  freespace key ",
 317                        genbits, alloc_freespace_genbits(a) >> 56);
 318                 bch2_bkey_val_to_text(&buf, c, freespace_k);
 319                 prt_printf(&buf, "\n  ");
 320                 bch2_bkey_val_to_text(&buf, c, k);
 321                 bch2_trans_inconsistent(trans, "%s", buf.buf);
 322                 ob = ERR_PTR(-EIO);
 323                 goto err;
 324
 325         }
 326
 327         if (a.data_type != BCH_DATA_free) {
 328                 prt_printf(&buf, "non free bucket in freespace btree\n"
 329                        "  freespace key ");
 330                 bch2_bkey_val_to_text(&buf, c, freespace_k);
 331                 prt_printf(&buf, "\n  ");
 332                 bch2_bkey_val_to_text(&buf, c, k);
 333                 bch2_trans_inconsistent(trans, "%s", buf.buf);
 334                 ob = ERR_PTR(-EIO);
 335                 goto err;
 336         }
 337
 338         if (!test_bit(BCH_FS_CHECK_BACKPOINTERS_DONE, &c->flags)) {
 339                 struct bch_backpointer bp;
 340                 u64 bp_offset = 0;
 341
 342                 ret = bch2_get_next_backpointer(trans, POS(ca->dev_idx, b), -1,
 343                                                 &bp_offset, &bp,
 344                                                 BTREE_ITER_NOPRESERVE);
 345                 if (ret) {
 346                         ob = ERR_PTR(ret);
 347                         goto err;
 348                 }
 349
 350                 if (bp_offset != U64_MAX) {
 351                         /*
 352                          * Bucket may have data in it - we don't call
 353                          * bc2h_trans_inconnsistent() because fsck hasn't
 354                          * finished yet
 355                          */
 356                         ob = NULL;
 357                         goto err;
 358                 }
 359         }
 360
 361         ob = __try_alloc_bucket(c, ca, b, reserve, &a, s, cl);
 362         if (!ob)
 363                 iter.path->preserve = false;
 364 err:
 365         set_btree_iter_dontneed(&iter);
 366         bch2_trans_iter_exit(trans, &iter);
 367         printbuf_exit(&buf);
 368         return ob;
 369 }
 370
 371 static struct open_bucket *try_alloc_partial_bucket(struct bch_fs *c, struct bch_dev *ca,
 372                                                     enum alloc_reserve reserve)
 373 {
 374         struct open_bucket *ob;
 375         int i;
 376
 377         spin_lock(&c->freelist_lock);
 378
 379         for (i = ca->open_buckets_partial_nr - 1; i >= 0; --i) {
 380                 ob = c->open_buckets + ca->open_buckets_partial[i];
 381
 382                 if (reserve <= ob->alloc_reserve) {
 383                         array_remove_item(ca->open_buckets_partial,
 384                                           ca->open_buckets_partial_nr,
 385                                           i);
 386                         ob->on_partial_list = false;
 387                         ob->alloc_reserve = reserve;
 388                         spin_unlock(&c->freelist_lock);
 389                         return ob;
 390                 }
 391         }
 392
 393         spin_unlock(&c->freelist_lock);
 394         return NULL;
 395 }
 396
 397 /*
 398  * This path is for before the freespace btree is initialized:
 399  *
 400  * If ca->new_fs_bucket_idx is nonzero, we haven't yet marked superblock &
 401  * journal buckets - journal buckets will be < ca->new_fs_bucket_idx
 402  */
 403 static noinline struct open_bucket *
 404 bch2_bucket_alloc_early(struct btree_trans *trans,
 405                         struct bch_dev *ca,
 406                         enum alloc_reserve reserve,
 407                         struct bucket_alloc_state *s,
 408                         struct closure *cl)
 409 {
 410         struct btree_iter iter;
 411         struct bkey_s_c k;
 412         struct open_bucket *ob = NULL;
 413         int ret;
 414
 415         s->cur_bucket = max_t(u64, s->cur_bucket, ca->mi.first_bucket);
 416         s->cur_bucket = max_t(u64, s->cur_bucket, ca->new_fs_bucket_idx);
 417
 418         for_each_btree_key_norestart(trans, iter, BTREE_ID_alloc, POS(ca->dev_idx, s->cur_bucket),
 419                            BTREE_ITER_SLOTS, k, ret) {
 420                 struct bch_alloc_v4 a;
 421
 422                 if (bkey_cmp(k.k->p, POS(ca->dev_idx, ca->mi.nbuckets)) >= 0)
 423                         break;
 424
 425                 if (ca->new_fs_bucket_idx &&
 426                     is_superblock_bucket(ca, k.k->p.offset))
 427                         continue;
 428
 429                 bch2_alloc_to_v4(k, &a);
 430
 431                 if (a.data_type != BCH_DATA_free)
 432                         continue;
 433
 434                 s->buckets_seen++;
 435
 436                 ob = __try_alloc_bucket(trans->c, ca, k.k->p.offset, reserve, &a, s, cl);
 437                 if (ob)
 438                         break;
 439         }
 440         bch2_trans_iter_exit(trans, &iter);
 441
 442         s->cur_bucket = iter.pos.offset;
 443
 444         return ob ?: ERR_PTR(ret ?: -BCH_ERR_no_buckets_found);
 445 }
 446
 447 static struct open_bucket *bch2_bucket_alloc_freelist(struct btree_trans *trans,
 448                                                    struct bch_dev *ca,
 449                                                    enum alloc_reserve reserve,
 450                                                    struct bucket_alloc_state *s,
 451                                                    struct closure *cl)
 452 {
 453         struct btree_iter iter;
 454         struct bkey_s_c k;
 455         struct open_bucket *ob = NULL;
 456         int ret;
 457
 458         BUG_ON(ca->new_fs_bucket_idx);
 459
 460         /*
 461          * XXX:
 462          * On transaction restart, we'd like to restart from the bucket we were
 463          * at previously
 464          */
 465         for_each_btree_key_norestart(trans, iter, BTREE_ID_freespace,
 466                                      POS(ca->dev_idx, s->cur_bucket), 0, k, ret) {
 467                 if (k.k->p.inode != ca->dev_idx)
 468                         break;
 469
 470                 for (s->cur_bucket = max(s->cur_bucket, bkey_start_offset(k.k));
 471                      s->cur_bucket < k.k->p.offset;
 472                      s->cur_bucket++) {
 473                         ret = btree_trans_too_many_iters(trans);
 474                         if (ret)
 475                                 break;
 476
 477                         s->buckets_seen++;
 478
 479                         ob = try_alloc_bucket(trans, ca, reserve,
 480                                               s->cur_bucket, s, k, cl);
 481                         if (ob)
 482                                 break;
 483                 }
 484
 485                 if (ob || ret)
 486                         break;
 487         }
 488         bch2_trans_iter_exit(trans, &iter);
 489
 490         return ob ?: ERR_PTR(ret);
 491 }
 492
 493 /**
 494  * bch_bucket_alloc - allocate a single bucket from a specific device
 495  *
 496  * Returns index of bucket on success, 0 on failure
 497  */
 498 static struct open_bucket *bch2_bucket_alloc_trans(struct btree_trans *trans,
 499                                       struct bch_dev *ca,
 500                                       enum alloc_reserve reserve,
 501                                       bool may_alloc_partial,
 502                                       struct closure *cl,
 503                                       struct bch_dev_usage *usage)
 504 {
 505         struct bch_fs *c = trans->c;
 506         struct open_bucket *ob = NULL;
 507         bool freespace_initialized = READ_ONCE(ca->mi.freespace_initialized);
 508         u64 start = freespace_initialized ? 0 : ca->bucket_alloc_trans_early_cursor;
 509         u64 avail;
 510         struct bucket_alloc_state s = { .cur_bucket = start };
 511         bool waiting = false;
 512 again:
 513         bch2_dev_usage_read_fast(ca, usage);
 514         avail = dev_buckets_free(ca, *usage, reserve);
 515
 516         if (usage->d[BCH_DATA_need_discard].buckets > avail)
 517                 bch2_do_discards(c);
 518
 519         if (usage->d[BCH_DATA_need_gc_gens].buckets > avail)
 520                 bch2_do_gc_gens(c);
 521
 522         if (should_invalidate_buckets(ca, *usage))
 523                 bch2_do_invalidates(c);
 524
 525         if (!avail) {
 526                 if (cl && !waiting) {
 527                         closure_wait(&c->freelist_wait, cl);
 528                         waiting = true;
 529                         goto again;
 530                 }
 531
 532                 if (!c->blocked_allocate)
 533                         c->blocked_allocate = local_clock();
 534
 535                 ob = ERR_PTR(-BCH_ERR_freelist_empty);
 536                 goto err;
 537         }
 538
 539         if (waiting)
 540                 closure_wake_up(&c->freelist_wait);
 541
 542         if (may_alloc_partial) {
 543                 ob = try_alloc_partial_bucket(c, ca, reserve);
 544                 if (ob)
 545                         return ob;
 546         }
 547
 548         ob = likely(ca->mi.freespace_initialized)
 549                 ? bch2_bucket_alloc_freelist(trans, ca, reserve, &s, cl)
 550                 : bch2_bucket_alloc_early(trans, ca, reserve, &s, cl);
 551
 552         if (s.skipped_need_journal_commit * 2 > avail)
 553                 bch2_journal_flush_async(&c->journal, NULL);
 554
 555         if (!ob && !freespace_initialized && start) {
 556                 start = s.cur_bucket = 0;
 557                 goto again;
 558         }
 559
 560         if (!freespace_initialized)
 561                 ca->bucket_alloc_trans_early_cursor = s.cur_bucket;
 562 err:
 563         if (!ob)
 564                 ob = ERR_PTR(-BCH_ERR_no_buckets_found);
 565
 566         if (!IS_ERR(ob))
 567                 trace_and_count(c, bucket_alloc, ca, bch2_alloc_reserves[reserve],
 568                                 may_alloc_partial, ob->bucket);
 569         else if (!bch2_err_matches(PTR_ERR(ob), BCH_ERR_transaction_restart))
 570                 trace_and_count(c, bucket_alloc_fail,
 571                                 ca, bch2_alloc_reserves[reserve],
 572                                 usage->d[BCH_DATA_free].buckets,
 573                                 avail,
 574                                 bch2_copygc_wait_amount(c),
 575                                 c->copygc_wait - atomic64_read(&c->io_clock[WRITE].now),
 576                                 &s,
 577                                 cl == NULL,
 578                                 bch2_err_str(PTR_ERR(ob)));
 579
 580         return ob;
 581 }
 582
 583 struct open_bucket *bch2_bucket_alloc(struct bch_fs *c, struct bch_dev *ca,
 584                                       enum alloc_reserve reserve,
 585                                       bool may_alloc_partial,
 586                                       struct closure *cl)
 587 {
 588         struct bch_dev_usage usage;
 589         struct open_bucket *ob;
 590
 591         bch2_trans_do(c, NULL, NULL, 0,
 592                       PTR_ERR_OR_ZERO(ob = bch2_bucket_alloc_trans(&trans, ca, reserve,
 593                                                         may_alloc_partial, cl, &usage)));
 594         return ob;
 595 }
 596
 597 static int __dev_stripe_cmp(struct dev_stripe_state *stripe,
 598                             unsigned l, unsigned r)
 599 {
 600         return ((stripe->next_alloc[l] > stripe->next_alloc[r]) -
 601                 (stripe->next_alloc[l] < stripe->next_alloc[r]));
 602 }
 603
 604 #define dev_stripe_cmp(l, r) __dev_stripe_cmp(stripe, l, r)
 605
 606 struct dev_alloc_list bch2_dev_alloc_list(struct bch_fs *c,
 607                                           struct dev_stripe_state *stripe,
 608                                           struct bch_devs_mask *devs)
 609 {
 610         struct dev_alloc_list ret = { .nr = 0 };
 611         unsigned i;
 612
 613         for_each_set_bit(i, devs->d, BCH_SB_MEMBERS_MAX)
 614                 ret.devs[ret.nr++] = i;
 615
 616         bubble_sort(ret.devs, ret.nr, dev_stripe_cmp);
 617         return ret;
 618 }
 619
 620 static inline void bch2_dev_stripe_increment_inlined(struct bch_dev *ca,
 621                                struct dev_stripe_state *stripe,
 622                                struct bch_dev_usage *usage)
 623 {
 624         u64 *v = stripe->next_alloc + ca->dev_idx;
 625         u64 free_space = dev_buckets_available(ca, RESERVE_none);
 626         u64 free_space_inv = free_space
 627                 ? div64_u64(1ULL << 48, free_space)
 628                 : 1ULL << 48;
 629         u64 scale = *v / 4;
 630
 631         if (*v + free_space_inv >= *v)
 632                 *v += free_space_inv;
 633         else
 634                 *v = U64_MAX;
 635
 636         for (v = stripe->next_alloc;
 637              v < stripe->next_alloc + ARRAY_SIZE(stripe->next_alloc); v++)
 638                 *v = *v < scale ? 0 : *v - scale;
 639 }
 640
 641 void bch2_dev_stripe_increment(struct bch_dev *ca,
 642                                struct dev_stripe_state *stripe)
 643 {
 644         struct bch_dev_usage usage;
 645
 646         bch2_dev_usage_read_fast(ca, &usage);
 647         bch2_dev_stripe_increment_inlined(ca, stripe, &usage);
 648 }
 649
 650 #define BUCKET_MAY_ALLOC_PARTIAL        (1 << 0)
 651 #define BUCKET_ALLOC_USE_DURABILITY     (1 << 1)
 652
 653 static void add_new_bucket(struct bch_fs *c,
 654                            struct open_buckets *ptrs,
 655                            struct bch_devs_mask *devs_may_alloc,
 656                            unsigned *nr_effective,
 657                            bool *have_cache,
 658                            unsigned flags,
 659                            struct open_bucket *ob)
 660 {
 661         unsigned durability =
 662                 bch_dev_bkey_exists(c, ob->dev)->mi.durability;
 663
 664         __clear_bit(ob->dev, devs_may_alloc->d);
 665         *nr_effective   += (flags & BUCKET_ALLOC_USE_DURABILITY)
 666                 ? durability : 1;
 667         *have_cache     |= !durability;
 668
 669         ob_push(c, ptrs, ob);
 670 }
 671
 672 static int bch2_bucket_alloc_set_trans(struct btree_trans *trans,
 673                       struct open_buckets *ptrs,
 674                       struct dev_stripe_state *stripe,
 675                       struct bch_devs_mask *devs_may_alloc,
 676                       unsigned nr_replicas,
 677                       unsigned *nr_effective,
 678                       bool *have_cache,
 679                       enum alloc_reserve reserve,
 680                       unsigned flags,
 681                       struct closure *cl)
 682 {
 683         struct bch_fs *c = trans->c;
 684         struct dev_alloc_list devs_sorted =
 685                 bch2_dev_alloc_list(c, stripe, devs_may_alloc);
 686         unsigned dev;
 687         struct bch_dev *ca;
 688         int ret = -BCH_ERR_insufficient_devices;
 689         unsigned i;
 690
 691         BUG_ON(*nr_effective >= nr_replicas);
 692
 693         for (i = 0; i < devs_sorted.nr; i++) {
 694                 struct bch_dev_usage usage;
 695                 struct open_bucket *ob;
 696
 697                 dev = devs_sorted.devs[i];
 698
 699                 rcu_read_lock();
 700                 ca = rcu_dereference(c->devs[dev]);
 701                 if (ca)
 702                         percpu_ref_get(&ca->ref);
 703                 rcu_read_unlock();
 704
 705                 if (!ca)
 706                         continue;
 707
 708                 if (!ca->mi.durability && *have_cache) {
 709                         percpu_ref_put(&ca->ref);
 710                         continue;
 711                 }
 712
 713                 ob = bch2_bucket_alloc_trans(trans, ca, reserve,
 714                                 flags & BUCKET_MAY_ALLOC_PARTIAL, cl, &usage);
 715                 if (!IS_ERR(ob))
 716                         bch2_dev_stripe_increment_inlined(ca, stripe, &usage);
 717                 percpu_ref_put(&ca->ref);
 718
 719                 if (IS_ERR(ob)) {
 720                         ret = PTR_ERR(ob);
 721                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart) || cl)
 722                                 break;
 723                         continue;
 724                 }
 725
 726                 add_new_bucket(c, ptrs, devs_may_alloc,
 727                                nr_effective, have_cache, flags, ob);
 728
 729                 if (*nr_effective >= nr_replicas) {
 730                         ret = 0;
 731                         break;
 732                 }
 733         }
 734
 735         return ret;
 736 }
 737
 738 int bch2_bucket_alloc_set(struct bch_fs *c,
 739                       struct open_buckets *ptrs,
 740                       struct dev_stripe_state *stripe,
 741                       struct bch_devs_mask *devs_may_alloc,
 742                       unsigned nr_replicas,
 743                       unsigned *nr_effective,
 744                       bool *have_cache,
 745                       enum alloc_reserve reserve,
 746                       unsigned flags,
 747                       struct closure *cl)
 748 {
 749         return bch2_trans_do(c, NULL, NULL, 0,
 750                       bch2_bucket_alloc_set_trans(&trans, ptrs, stripe,
 751                                               devs_may_alloc, nr_replicas,
 752                                               nr_effective, have_cache, reserve,
 753                                               flags, cl));
 754 }
 755
 756 /* Allocate from stripes: */
 757
 758 /*
 759  * if we can't allocate a new stripe because there are already too many
 760  * partially filled stripes, force allocating from an existing stripe even when
 761  * it's to a device we don't want:
 762  */
 763
 764 static int bucket_alloc_from_stripe(struct bch_fs *c,
 765                          struct open_buckets *ptrs,
 766                          struct write_point *wp,
 767                          struct bch_devs_mask *devs_may_alloc,
 768                          u16 target,
 769                          unsigned erasure_code,
 770                          unsigned nr_replicas,
 771                          unsigned *nr_effective,
 772                          bool *have_cache,
 773                          unsigned flags,
 774                          struct closure *cl)
 775 {
 776         struct dev_alloc_list devs_sorted;
 777         struct ec_stripe_head *h;
 778         struct open_bucket *ob;
 779         struct bch_dev *ca;
 780         unsigned i, ec_idx;
 781
 782         if (!erasure_code)
 783                 return 0;
 784
 785         if (nr_replicas < 2)
 786                 return 0;
 787
 788         if (ec_open_bucket(c, ptrs))
 789                 return 0;
 790
 791         h = bch2_ec_stripe_head_get(c, target, 0, nr_replicas - 1,
 792                                     wp == &c->copygc_write_point,
 793                                     cl);
 794         if (IS_ERR(h))
 795                 return -PTR_ERR(h);
 796         if (!h)
 797                 return 0;
 798
 799         devs_sorted = bch2_dev_alloc_list(c, &wp->stripe, devs_may_alloc);
 800
 801         for (i = 0; i < devs_sorted.nr; i++)
 802                 for (ec_idx = 0; ec_idx < h->s->nr_data; ec_idx++) {
 803                         if (!h->s->blocks[ec_idx])
 804                                 continue;
 805
 806                         ob = c->open_buckets + h->s->blocks[ec_idx];
 807                         if (ob->dev == devs_sorted.devs[i] &&
 808                             !test_and_set_bit(ec_idx, h->s->blocks_allocated))
 809                                 goto got_bucket;
 810                 }
 811         goto out_put_head;
 812 got_bucket:
 813         ca = bch_dev_bkey_exists(c, ob->dev);
 814
 815         ob->ec_idx      = ec_idx;
 816         ob->ec          = h->s;
 817
 818         add_new_bucket(c, ptrs, devs_may_alloc,
 819                        nr_effective, have_cache, flags, ob);
 820         atomic_inc(&h->s->pin);
 821 out_put_head:
 822         bch2_ec_stripe_head_put(c, h);
 823         return 0;
 824 }
 825
 826 /* Sector allocator */
 827
 828 static void get_buckets_from_writepoint(struct bch_fs *c,
 829                                         struct open_buckets *ptrs,
 830                                         struct write_point *wp,
 831                                         struct bch_devs_mask *devs_may_alloc,
 832                                         unsigned nr_replicas,
 833                                         unsigned *nr_effective,
 834                                         bool *have_cache,
 835                                         unsigned flags,
 836                                         bool need_ec)
 837 {
 838         struct open_buckets ptrs_skip = { .nr = 0 };
 839         struct open_bucket *ob;
 840         unsigned i;
 841
 842         open_bucket_for_each(c, &wp->ptrs, ob, i) {
 843                 struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
 844
 845                 if (*nr_effective < nr_replicas &&
 846                     test_bit(ob->dev, devs_may_alloc->d) &&
 847                     (ca->mi.durability ||
 848                      (wp->data_type == BCH_DATA_user && !*have_cache)) &&
 849                     (ob->ec || !need_ec)) {
 850                         add_new_bucket(c, ptrs, devs_may_alloc,
 851                                        nr_effective, have_cache,
 852                                        flags, ob);
 853                 } else {
 854                         ob_push(c, &ptrs_skip, ob);
 855                 }
 856         }
 857         wp->ptrs = ptrs_skip;
 858 }
 859
 860 static int open_bucket_add_buckets(struct btree_trans *trans,
 861                         struct open_buckets *ptrs,
 862                         struct write_point *wp,
 863                         struct bch_devs_list *devs_have,
 864                         u16 target,
 865                         unsigned erasure_code,
 866                         unsigned nr_replicas,
 867                         unsigned *nr_effective,
 868                         bool *have_cache,
 869                         enum alloc_reserve reserve,
 870                         unsigned flags,
 871                         struct closure *_cl)
 872 {
 873         struct bch_fs *c = trans->c;
 874         struct bch_devs_mask devs;
 875         struct open_bucket *ob;
 876         struct closure *cl = NULL;
 877         int ret;
 878         unsigned i;
 879
 880         rcu_read_lock();
 881         devs = target_rw_devs(c, wp->data_type, target);
 882         rcu_read_unlock();
 883
 884         /* Don't allocate from devices we already have pointers to: */
 885         for (i = 0; i < devs_have->nr; i++)
 886                 __clear_bit(devs_have->devs[i], devs.d);
 887
 888         open_bucket_for_each(c, ptrs, ob, i)
 889                 __clear_bit(ob->dev, devs.d);
 890
 891         if (erasure_code) {
 892                 if (!ec_open_bucket(c, ptrs)) {
 893                         get_buckets_from_writepoint(c, ptrs, wp, &devs,
 894                                                     nr_replicas, nr_effective,
 895                                                     have_cache, flags, true);
 896                         if (*nr_effective >= nr_replicas)
 897                                 return 0;
 898                 }
 899
 900                 if (!ec_open_bucket(c, ptrs)) {
 901                         ret = bucket_alloc_from_stripe(c, ptrs, wp, &devs,
 902                                                  target, erasure_code,
 903                                                  nr_replicas, nr_effective,
 904                                                  have_cache, flags, _cl);
 905                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
 906                             bch2_err_matches(ret, BCH_ERR_freelist_empty) ||
 907                             bch2_err_matches(ret, BCH_ERR_open_buckets_empty))
 908                                 return ret;
 909                         if (*nr_effective >= nr_replicas)
 910                                 return 0;
 911                 }
 912         }
 913
 914         get_buckets_from_writepoint(c, ptrs, wp, &devs,
 915                                     nr_replicas, nr_effective,
 916                                     have_cache, flags, false);
 917         if (*nr_effective >= nr_replicas)
 918                 return 0;
 919
 920 retry_blocking:
 921         /*
 922          * Try nonblocking first, so that if one device is full we'll try from
 923          * other devices:
 924          */
 925         ret = bch2_bucket_alloc_set_trans(trans, ptrs, &wp->stripe, &devs,
 926                                 nr_replicas, nr_effective, have_cache,
 927                                 reserve, flags, cl);
 928         if (ret &&
 929             !bch2_err_matches(ret, BCH_ERR_transaction_restart) &&
 930             !bch2_err_matches(ret, BCH_ERR_insufficient_devices) &&
 931             !cl && _cl) {
 932                 cl = _cl;
 933                 goto retry_blocking;
 934         }
 935
 936         return ret;
 937 }
 938
 939 void bch2_open_buckets_stop_dev(struct bch_fs *c, struct bch_dev *ca,
 940                                 struct open_buckets *obs)
 941 {
 942         struct open_buckets ptrs = { .nr = 0 };
 943         struct open_bucket *ob, *ob2;
 944         unsigned i, j;
 945
 946         open_bucket_for_each(c, obs, ob, i) {
 947                 bool drop = !ca || ob->dev == ca->dev_idx;
 948
 949                 if (!drop && ob->ec) {
 950                         mutex_lock(&ob->ec->lock);
 951                         for (j = 0; j < ob->ec->new_stripe.key.v.nr_blocks; j++) {
 952                                 if (!ob->ec->blocks[j])
 953                                         continue;
 954
 955                                 ob2 = c->open_buckets + ob->ec->blocks[j];
 956                                 drop |= ob2->dev == ca->dev_idx;
 957                         }
 958                         mutex_unlock(&ob->ec->lock);
 959                 }
 960
 961                 if (drop)
 962                         bch2_open_bucket_put(c, ob);
 963                 else
 964                         ob_push(c, &ptrs, ob);
 965         }
 966
 967         *obs = ptrs;
 968 }
 969
 970 void bch2_writepoint_stop(struct bch_fs *c, struct bch_dev *ca,
 971                           struct write_point *wp)
 972 {
 973         mutex_lock(&wp->lock);
 974         bch2_open_buckets_stop_dev(c, ca, &wp->ptrs);
 975         mutex_unlock(&wp->lock);
 976 }
 977
 978 static inline struct hlist_head *writepoint_hash(struct bch_fs *c,
 979                                                  unsigned long write_point)
 980 {
 981         unsigned hash =
 982                 hash_long(write_point, ilog2(ARRAY_SIZE(c->write_points_hash)));
 983
 984         return &c->write_points_hash[hash];
 985 }
 986
 987 static struct write_point *__writepoint_find(struct hlist_head *head,
 988                                              unsigned long write_point)
 989 {
 990         struct write_point *wp;
 991
 992         rcu_read_lock();
 993         hlist_for_each_entry_rcu(wp, head, node)
 994                 if (wp->write_point == write_point)
 995                         goto out;
 996         wp = NULL;
 997 out:
 998         rcu_read_unlock();
 999         return wp;
1000 }
1001
1002 static inline bool too_many_writepoints(struct bch_fs *c, unsigned factor)
1003 {
1004         u64 stranded    = c->write_points_nr * c->bucket_size_max;
1005         u64 free        = bch2_fs_usage_read_short(c).free;
1006
1007         return stranded * factor > free;
1008 }
1009
1010 static bool try_increase_writepoints(struct bch_fs *c)
1011 {
1012         struct write_point *wp;
1013
1014         if (c->write_points_nr == ARRAY_SIZE(c->write_points) ||
1015             too_many_writepoints(c, 32))
1016                 return false;
1017
1018         wp = c->write_points + c->write_points_nr++;
1019         hlist_add_head_rcu(&wp->node, writepoint_hash(c, wp->write_point));
1020         return true;
1021 }
1022
1023 static bool try_decrease_writepoints(struct bch_fs *c,
1024                                      unsigned old_nr)
1025 {
1026         struct write_point *wp;
1027
1028         mutex_lock(&c->write_points_hash_lock);
1029         if (c->write_points_nr < old_nr) {
1030                 mutex_unlock(&c->write_points_hash_lock);
1031                 return true;
1032         }
1033
1034         if (c->write_points_nr == 1 ||
1035             !too_many_writepoints(c, 8)) {
1036                 mutex_unlock(&c->write_points_hash_lock);
1037                 return false;
1038         }
1039
1040         wp = c->write_points + --c->write_points_nr;
1041
1042         hlist_del_rcu(&wp->node);
1043         mutex_unlock(&c->write_points_hash_lock);
1044
1045         bch2_writepoint_stop(c, NULL, wp);
1046         return true;
1047 }
1048
1049 static void bch2_trans_mutex_lock(struct btree_trans *trans,
1050                                   struct mutex *lock)
1051 {
1052         if (!mutex_trylock(lock)) {
1053                 bch2_trans_unlock(trans);
1054                 mutex_lock(lock);
1055         }
1056 }
1057
1058 static struct write_point *writepoint_find(struct btree_trans *trans,
1059                                            unsigned long write_point)
1060 {
1061         struct bch_fs *c = trans->c;
1062         struct write_point *wp, *oldest;
1063         struct hlist_head *head;
1064
1065         if (!(write_point & 1UL)) {
1066                 wp = (struct write_point *) write_point;
1067                 bch2_trans_mutex_lock(trans, &wp->lock);
1068                 return wp;
1069         }
1070
1071         head = writepoint_hash(c, write_point);
1072 restart_find:
1073         wp = __writepoint_find(head, write_point);
1074         if (wp) {
1075 lock_wp:
1076                 bch2_trans_mutex_lock(trans, &wp->lock);
1077                 if (wp->write_point == write_point)
1078                         goto out;
1079                 mutex_unlock(&wp->lock);
1080                 goto restart_find;
1081         }
1082 restart_find_oldest:
1083         oldest = NULL;
1084         for (wp = c->write_points;
1085              wp < c->write_points + c->write_points_nr; wp++)
1086                 if (!oldest || time_before64(wp->last_used, oldest->last_used))
1087                         oldest = wp;
1088
1089         bch2_trans_mutex_lock(trans, &oldest->lock);
1090         bch2_trans_mutex_lock(trans, &c->write_points_hash_lock);
1091         if (oldest >= c->write_points + c->write_points_nr ||
1092             try_increase_writepoints(c)) {
1093                 mutex_unlock(&c->write_points_hash_lock);
1094                 mutex_unlock(&oldest->lock);
1095                 goto restart_find_oldest;
1096         }
1097
1098         wp = __writepoint_find(head, write_point);
1099         if (wp && wp != oldest) {
1100                 mutex_unlock(&c->write_points_hash_lock);
1101                 mutex_unlock(&oldest->lock);
1102                 goto lock_wp;
1103         }
1104
1105         wp = oldest;
1106         hlist_del_rcu(&wp->node);
1107         wp->write_point = write_point;
1108         hlist_add_head_rcu(&wp->node, head);
1109         mutex_unlock(&c->write_points_hash_lock);
1110 out:
1111         wp->last_used = local_clock();
1112         return wp;
1113 }
1114
1115 /*
1116  * Get us an open_bucket we can allocate from, return with it locked:
1117  */
1118 int bch2_alloc_sectors_start_trans(struct btree_trans *trans,
1119                                    unsigned target,
1120                                    unsigned erasure_code,
1121                                    struct write_point_specifier write_point,
1122                                    struct bch_devs_list *devs_have,
1123                                    unsigned nr_replicas,
1124                                    unsigned nr_replicas_required,
1125                                    enum alloc_reserve reserve,
1126                                    unsigned flags,
1127                                    struct closure *cl,
1128                                    struct write_point **wp_ret)
1129 {
1130         struct bch_fs *c = trans->c;
1131         struct write_point *wp;
1132         struct open_bucket *ob;
1133         struct open_buckets ptrs;
1134         unsigned nr_effective, write_points_nr;
1135         unsigned ob_flags = 0;
1136         bool have_cache;
1137         int ret;
1138         int i;
1139
1140         if (!(flags & BCH_WRITE_ONLY_SPECIFIED_DEVS))
1141                 ob_flags |= BUCKET_ALLOC_USE_DURABILITY;
1142
1143         BUG_ON(!nr_replicas || !nr_replicas_required);
1144 retry:
1145         ptrs.nr         = 0;
1146         nr_effective    = 0;
1147         write_points_nr = c->write_points_nr;
1148         have_cache      = false;
1149
1150         *wp_ret = wp = writepoint_find(trans, write_point.v);
1151
1152         if (wp->data_type == BCH_DATA_user)
1153                 ob_flags |= BUCKET_MAY_ALLOC_PARTIAL;
1154
1155         /* metadata may not allocate on cache devices: */
1156         if (wp->data_type != BCH_DATA_user)
1157                 have_cache = true;
1158
1159         if (!target || (flags & BCH_WRITE_ONLY_SPECIFIED_DEVS)) {
1160                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1161                                               target, erasure_code,
1162                                               nr_replicas, &nr_effective,
1163                                               &have_cache, reserve,
1164                                               ob_flags, cl);
1165         } else {
1166                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1167                                               target, erasure_code,
1168                                               nr_replicas, &nr_effective,
1169                                               &have_cache, reserve,
1170                                               ob_flags, NULL);
1171                 if (!ret ||
1172                     bch2_err_matches(ret, BCH_ERR_transaction_restart))
1173                         goto alloc_done;
1174
1175                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1176                                               0, erasure_code,
1177                                               nr_replicas, &nr_effective,
1178                                               &have_cache, reserve,
1179                                               ob_flags, cl);
1180         }
1181 alloc_done:
1182         BUG_ON(!ret && nr_effective < nr_replicas);
1183
1184         if (erasure_code && !ec_open_bucket(c, &ptrs))
1185                 pr_debug("failed to get ec bucket: ret %u", ret);
1186
1187         if (ret == -BCH_ERR_insufficient_devices &&
1188             nr_effective >= nr_replicas_required)
1189                 ret = 0;
1190
1191         if (ret)
1192                 goto err;
1193
1194         /* Free buckets we didn't use: */
1195         open_bucket_for_each(c, &wp->ptrs, ob, i)
1196                 open_bucket_free_unused(c, wp, ob);
1197
1198         wp->ptrs = ptrs;
1199
1200         wp->sectors_free = UINT_MAX;
1201
1202         open_bucket_for_each(c, &wp->ptrs, ob, i)
1203                 wp->sectors_free = min(wp->sectors_free, ob->sectors_free);
1204
1205         BUG_ON(!wp->sectors_free || wp->sectors_free == UINT_MAX);
1206
1207         return 0;
1208 err:
1209         open_bucket_for_each(c, &wp->ptrs, ob, i)
1210                 if (ptrs.nr < ARRAY_SIZE(ptrs.v))
1211                         ob_push(c, &ptrs, ob);
1212                 else
1213                         open_bucket_free_unused(c, wp, ob);
1214         wp->ptrs = ptrs;
1215
1216         mutex_unlock(&wp->lock);
1217
1218         if (bch2_err_matches(ret, BCH_ERR_freelist_empty) &&
1219             try_decrease_writepoints(c, write_points_nr))
1220                 goto retry;
1221
1222         if (bch2_err_matches(ret, BCH_ERR_open_buckets_empty) ||
1223             bch2_err_matches(ret, BCH_ERR_freelist_empty))
1224                 return cl
1225                         ? -EAGAIN
1226                         : -BCH_ERR_ENOSPC_bucket_alloc;
1227
1228         if (bch2_err_matches(ret, BCH_ERR_insufficient_devices))
1229                 return -EROFS;
1230
1231         return ret;
1232 }
1233
1234 struct bch_extent_ptr bch2_ob_ptr(struct bch_fs *c, struct open_bucket *ob)
1235 {
1236         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
1237
1238         return (struct bch_extent_ptr) {
1239                 .type   = 1 << BCH_EXTENT_ENTRY_ptr,
1240                 .gen    = ob->gen,
1241                 .dev    = ob->dev,
1242                 .offset = bucket_to_sector(ca, ob->bucket) +
1243                         ca->mi.bucket_size -
1244                         ob->sectors_free,
1245         };
1246 }
1247
1248 /*
1249  * Append pointers to the space we just allocated to @k, and mark @sectors space
1250  * as allocated out of @ob
1251  */
1252 void bch2_alloc_sectors_append_ptrs(struct bch_fs *c, struct write_point *wp,
1253                                     struct bkey_i *k, unsigned sectors,
1254                                     bool cached)
1255
1256 {
1257         struct open_bucket *ob;
1258         unsigned i;
1259
1260         BUG_ON(sectors > wp->sectors_free);
1261         wp->sectors_free -= sectors;
1262
1263         open_bucket_for_each(c, &wp->ptrs, ob, i) {
1264                 struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
1265                 struct bch_extent_ptr ptr = bch2_ob_ptr(c, ob);
1266
1267                 ptr.cached = cached ||
1268                         (!ca->mi.durability &&
1269                          wp->data_type == BCH_DATA_user);
1270
1271                 bch2_bkey_append_ptr(k, ptr);
1272
1273                 BUG_ON(sectors > ob->sectors_free);
1274                 ob->sectors_free -= sectors;
1275         }
1276 }
1277
1278 /*
1279  * Append pointers to the space we just allocated to @k, and mark @sectors space
1280  * as allocated out of @ob
1281  */
1282 void bch2_alloc_sectors_done(struct bch_fs *c, struct write_point *wp)
1283 {
1284         struct open_buckets ptrs = { .nr = 0 }, keep = { .nr = 0 };
1285         struct open_bucket *ob;
1286         unsigned i;
1287
1288         open_bucket_for_each(c, &wp->ptrs, ob, i)
1289                 ob_push(c, !ob->sectors_free ? &ptrs : &keep, ob);
1290         wp->ptrs = keep;
1291
1292         mutex_unlock(&wp->lock);
1293
1294         bch2_open_buckets_put(c, &ptrs);
1295 }
1296
1297 static inline void writepoint_init(struct write_point *wp,
1298                                    enum bch_data_type type)
1299 {
1300         mutex_init(&wp->lock);
1301         wp->data_type = type;
1302
1303         INIT_WORK(&wp->index_update_work, bch2_write_point_do_index_updates);
1304         INIT_LIST_HEAD(&wp->writes);
1305         spin_lock_init(&wp->writes_lock);
1306 }
1307
1308 void bch2_fs_allocator_foreground_init(struct bch_fs *c)
1309 {
1310         struct open_bucket *ob;
1311         struct write_point *wp;
1312
1313         mutex_init(&c->write_points_hash_lock);
1314         c->write_points_nr = ARRAY_SIZE(c->write_points);
1315
1316         /* open bucket 0 is a sentinal NULL: */
1317         spin_lock_init(&c->open_buckets[0].lock);
1318
1319         for (ob = c->open_buckets + 1;
1320              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); ob++) {
1321                 spin_lock_init(&ob->lock);
1322                 c->open_buckets_nr_free++;
1323
1324                 ob->freelist = c->open_buckets_freelist;
1325                 c->open_buckets_freelist = ob - c->open_buckets;
1326         }
1327
1328         writepoint_init(&c->btree_write_point,          BCH_DATA_btree);
1329         writepoint_init(&c->rebalance_write_point,      BCH_DATA_user);
1330         writepoint_init(&c->copygc_write_point,         BCH_DATA_user);
1331
1332         for (wp = c->write_points;
1333              wp < c->write_points + c->write_points_nr; wp++) {
1334                 writepoint_init(wp, BCH_DATA_user);
1335
1336                 wp->last_used   = local_clock();
1337                 wp->write_point = (unsigned long) wp;
1338                 hlist_add_head_rcu(&wp->node,
1339                                    writepoint_hash(c, wp->write_point));
1340         }
1341 }
1342
1343 void bch2_open_buckets_to_text(struct printbuf *out, struct bch_fs *c)
1344 {
1345         struct open_bucket *ob;
1346
1347         for (ob = c->open_buckets;
1348              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets);
1349              ob++) {
1350                 spin_lock(&ob->lock);
1351                 if (ob->valid && !ob->on_partial_list) {
1352                         prt_printf(out, "%zu ref %u type %s %u:%llu:%u\n",
1353                                ob - c->open_buckets,
1354                                atomic_read(&ob->pin),
1355                                bch2_data_types[ob->data_type],
1356                                ob->dev, ob->bucket, ob->gen);
1357                 }
1358                 spin_unlock(&ob->lock);
1359         }
1360 }