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_write.h"
  29 #include "journal.h"
  30 #include "movinggc.h"
  31 #include "nocow_locking.h"
  32 #include "trace.h"
  33
  34 #include <linux/math64.h>
  35 #include <linux/rculist.h>
  36 #include <linux/rcupdate.h>
  37
  38 static void bch2_trans_mutex_lock_norelock(struct btree_trans *trans,
  39                                            struct mutex *lock)
  40 {
  41         if (!mutex_trylock(lock)) {
  42                 bch2_trans_unlock(trans);
  43                 mutex_lock(lock);
  44         }
  45 }
  46
  47 const char * const bch2_watermarks[] = {
  48 #define x(t) #t,
  49         BCH_WATERMARKS()
  50 #undef x
  51         NULL
  52 };
  53
  54 /*
  55  * Open buckets represent a bucket that's currently being allocated from.  They
  56  * serve two purposes:
  57  *
  58  *  - They track buckets that have been partially allocated, allowing for
  59  *    sub-bucket sized allocations - they're used by the sector allocator below
  60  *
  61  *  - They provide a reference to the buckets they own that mark and sweep GC
  62  *    can find, until the new allocation has a pointer to it inserted into the
  63  *    btree
  64  *
  65  * When allocating some space with the sector allocator, the allocation comes
  66  * with a reference to an open bucket - the caller is required to put that
  67  * reference _after_ doing the index update that makes its allocation reachable.
  68  */
  69
  70 void bch2_reset_alloc_cursors(struct bch_fs *c)
  71 {
  72         struct bch_dev *ca;
  73         unsigned i;
  74
  75         rcu_read_lock();
  76         for_each_member_device_rcu(ca, c, i, NULL)
  77                 ca->alloc_cursor = 0;
  78         rcu_read_unlock();
  79 }
  80
  81 static void bch2_open_bucket_hash_add(struct bch_fs *c, struct open_bucket *ob)
  82 {
  83         open_bucket_idx_t idx = ob - c->open_buckets;
  84         open_bucket_idx_t *slot = open_bucket_hashslot(c, ob->dev, ob->bucket);
  85
  86         ob->hash = *slot;
  87         *slot = idx;
  88 }
  89
  90 static void bch2_open_bucket_hash_remove(struct bch_fs *c, struct open_bucket *ob)
  91 {
  92         open_bucket_idx_t idx = ob - c->open_buckets;
  93         open_bucket_idx_t *slot = open_bucket_hashslot(c, ob->dev, ob->bucket);
  94
  95         while (*slot != idx) {
  96                 BUG_ON(!*slot);
  97                 slot = &c->open_buckets[*slot].hash;
  98         }
  99
 100         *slot = ob->hash;
 101         ob->hash = 0;
 102 }
 103
 104 void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
 105 {
 106         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
 107
 108         if (ob->ec) {
 109                 ec_stripe_new_put(c, ob->ec, STRIPE_REF_io);
 110                 return;
 111         }
 112
 113         percpu_down_read(&c->mark_lock);
 114         spin_lock(&ob->lock);
 115
 116         ob->valid = false;
 117         ob->data_type = 0;
 118
 119         spin_unlock(&ob->lock);
 120         percpu_up_read(&c->mark_lock);
 121
 122         spin_lock(&c->freelist_lock);
 123         bch2_open_bucket_hash_remove(c, ob);
 124
 125         ob->freelist = c->open_buckets_freelist;
 126         c->open_buckets_freelist = ob - c->open_buckets;
 127
 128         c->open_buckets_nr_free++;
 129         ca->nr_open_buckets--;
 130         spin_unlock(&c->freelist_lock);
 131
 132         closure_wake_up(&c->open_buckets_wait);
 133 }
 134
 135 void bch2_open_bucket_write_error(struct bch_fs *c,
 136                                   struct open_buckets *obs,
 137                                   unsigned dev)
 138 {
 139         struct open_bucket *ob;
 140         unsigned i;
 141
 142         open_bucket_for_each(c, obs, ob, i)
 143                 if (ob->dev == dev && ob->ec)
 144                         bch2_ec_bucket_cancel(c, ob);
 145 }
 146
 147 static struct open_bucket *bch2_open_bucket_alloc(struct bch_fs *c)
 148 {
 149         struct open_bucket *ob;
 150
 151         BUG_ON(!c->open_buckets_freelist || !c->open_buckets_nr_free);
 152
 153         ob = c->open_buckets + c->open_buckets_freelist;
 154         c->open_buckets_freelist = ob->freelist;
 155         atomic_set(&ob->pin, 1);
 156         ob->data_type = 0;
 157
 158         c->open_buckets_nr_free--;
 159         return ob;
 160 }
 161
 162 static void open_bucket_free_unused(struct bch_fs *c, struct open_bucket *ob)
 163 {
 164         BUG_ON(c->open_buckets_partial_nr >=
 165                ARRAY_SIZE(c->open_buckets_partial));
 166
 167         spin_lock(&c->freelist_lock);
 168         ob->on_partial_list = true;
 169         c->open_buckets_partial[c->open_buckets_partial_nr++] =
 170                 ob - c->open_buckets;
 171         spin_unlock(&c->freelist_lock);
 172
 173         closure_wake_up(&c->open_buckets_wait);
 174         closure_wake_up(&c->freelist_wait);
 175 }
 176
 177 /* _only_ for allocating the journal on a new device: */
 178 long bch2_bucket_alloc_new_fs(struct bch_dev *ca)
 179 {
 180         while (ca->new_fs_bucket_idx < ca->mi.nbuckets) {
 181                 u64 b = ca->new_fs_bucket_idx++;
 182
 183                 if (!is_superblock_bucket(ca, b) &&
 184                     (!ca->buckets_nouse || !test_bit(b, ca->buckets_nouse)))
 185                         return b;
 186         }
 187
 188         return -1;
 189 }
 190
 191 static inline unsigned open_buckets_reserved(enum bch_watermark watermark)
 192 {
 193         switch (watermark) {
 194         case BCH_WATERMARK_reclaim:
 195                 return 0;
 196         case BCH_WATERMARK_btree:
 197         case BCH_WATERMARK_btree_copygc:
 198                 return OPEN_BUCKETS_COUNT / 4;
 199         case BCH_WATERMARK_copygc:
 200                 return OPEN_BUCKETS_COUNT / 3;
 201         default:
 202                 return OPEN_BUCKETS_COUNT / 2;
 203         }
 204 }
 205
 206 static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *ca,
 207                                               u64 bucket,
 208                                               enum bch_watermark watermark,
 209                                               const struct bch_alloc_v4 *a,
 210                                               struct bucket_alloc_state *s,
 211                                               struct closure *cl)
 212 {
 213         struct open_bucket *ob;
 214
 215         if (unlikely(ca->buckets_nouse && test_bit(bucket, ca->buckets_nouse))) {
 216                 s->skipped_nouse++;
 217                 return NULL;
 218         }
 219
 220         if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {
 221                 s->skipped_open++;
 222                 return NULL;
 223         }
 224
 225         if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
 226                         c->journal.flushed_seq_ondisk, ca->dev_idx, bucket)) {
 227                 s->skipped_need_journal_commit++;
 228                 return NULL;
 229         }
 230
 231         if (bch2_bucket_nocow_is_locked(&c->nocow_locks, POS(ca->dev_idx, bucket))) {
 232                 s->skipped_nocow++;
 233                 return NULL;
 234         }
 235
 236         spin_lock(&c->freelist_lock);
 237
 238         if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(watermark))) {
 239                 if (cl)
 240                         closure_wait(&c->open_buckets_wait, cl);
 241
 242                 if (!c->blocked_allocate_open_bucket)
 243                         c->blocked_allocate_open_bucket = local_clock();
 244
 245                 spin_unlock(&c->freelist_lock);
 246                 return ERR_PTR(-BCH_ERR_open_buckets_empty);
 247         }
 248
 249         /* Recheck under lock: */
 250         if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {
 251                 spin_unlock(&c->freelist_lock);
 252                 s->skipped_open++;
 253                 return NULL;
 254         }
 255
 256         ob = bch2_open_bucket_alloc(c);
 257
 258         spin_lock(&ob->lock);
 259
 260         ob->valid       = true;
 261         ob->sectors_free = ca->mi.bucket_size;
 262         ob->dev         = ca->dev_idx;
 263         ob->gen         = a->gen;
 264         ob->bucket      = bucket;
 265         spin_unlock(&ob->lock);
 266
 267         ca->nr_open_buckets++;
 268         bch2_open_bucket_hash_add(c, ob);
 269
 270         if (c->blocked_allocate_open_bucket) {
 271                 bch2_time_stats_update(
 272                         &c->times[BCH_TIME_blocked_allocate_open_bucket],
 273                         c->blocked_allocate_open_bucket);
 274                 c->blocked_allocate_open_bucket = 0;
 275         }
 276
 277         if (c->blocked_allocate) {
 278                 bch2_time_stats_update(
 279                         &c->times[BCH_TIME_blocked_allocate],
 280                         c->blocked_allocate);
 281                 c->blocked_allocate = 0;
 282         }
 283
 284         spin_unlock(&c->freelist_lock);
 285         return ob;
 286 }
 287
 288 static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bch_dev *ca,
 289                                             enum bch_watermark watermark, u64 free_entry,
 290                                             struct bucket_alloc_state *s,
 291                                             struct bkey_s_c freespace_k,
 292                                             struct closure *cl)
 293 {
 294         struct bch_fs *c = trans->c;
 295         struct btree_iter iter = { NULL };
 296         struct bkey_s_c k;
 297         struct open_bucket *ob;
 298         struct bch_alloc_v4 a_convert;
 299         const struct bch_alloc_v4 *a;
 300         u64 b = free_entry & ~(~0ULL << 56);
 301         unsigned genbits = free_entry >> 56;
 302         struct printbuf buf = PRINTBUF;
 303         int ret;
 304
 305         if (b < ca->mi.first_bucket || b >= ca->mi.nbuckets) {
 306                 prt_printf(&buf, "freespace btree has bucket outside allowed range %u-%llu\n"
 307                        "  freespace key ",
 308                         ca->mi.first_bucket, ca->mi.nbuckets);
 309                 bch2_bkey_val_to_text(&buf, c, freespace_k);
 310                 bch2_trans_inconsistent(trans, "%s", buf.buf);
 311                 ob = ERR_PTR(-EIO);
 312                 goto err;
 313         }
 314
 315         k = bch2_bkey_get_iter(trans, &iter,
 316                                BTREE_ID_alloc, POS(ca->dev_idx, b),
 317                                BTREE_ITER_CACHED);
 318         ret = bkey_err(k);
 319         if (ret) {
 320                 ob = ERR_PTR(ret);
 321                 goto err;
 322         }
 323
 324         a = bch2_alloc_to_v4(k, &a_convert);
 325
 326         if (a->data_type != BCH_DATA_free) {
 327                 if (c->curr_recovery_pass <= BCH_RECOVERY_PASS_check_alloc_info) {
 328                         ob = NULL;
 329                         goto err;
 330                 }
 331
 332                 prt_printf(&buf, "non free bucket in freespace btree\n"
 333                        "  freespace key ");
 334                 bch2_bkey_val_to_text(&buf, c, freespace_k);
 335                 prt_printf(&buf, "\n  ");
 336                 bch2_bkey_val_to_text(&buf, c, k);
 337                 bch2_trans_inconsistent(trans, "%s", buf.buf);
 338                 ob = ERR_PTR(-EIO);
 339                 goto err;
 340         }
 341
 342         if (genbits != (alloc_freespace_genbits(*a) >> 56) &&
 343             c->curr_recovery_pass > BCH_RECOVERY_PASS_check_alloc_info) {
 344                 prt_printf(&buf, "bucket in freespace btree with wrong genbits (got %u should be %llu)\n"
 345                        "  freespace key ",
 346                        genbits, alloc_freespace_genbits(*a) >> 56);
 347                 bch2_bkey_val_to_text(&buf, c, freespace_k);
 348                 prt_printf(&buf, "\n  ");
 349                 bch2_bkey_val_to_text(&buf, c, k);
 350                 bch2_trans_inconsistent(trans, "%s", buf.buf);
 351                 ob = ERR_PTR(-EIO);
 352                 goto err;
 353         }
 354
 355         if (c->curr_recovery_pass <= BCH_RECOVERY_PASS_check_extents_to_backpointers) {
 356                 struct bch_backpointer bp;
 357                 struct bpos bp_pos = POS_MIN;
 358
 359                 ret = bch2_get_next_backpointer(trans, POS(ca->dev_idx, b), -1,
 360                                                 &bp_pos, &bp,
 361                                                 BTREE_ITER_NOPRESERVE);
 362                 if (ret) {
 363                         ob = ERR_PTR(ret);
 364                         goto err;
 365                 }
 366
 367                 if (!bkey_eq(bp_pos, POS_MAX)) {
 368                         /*
 369                          * Bucket may have data in it - we don't call
 370                          * bc2h_trans_inconnsistent() because fsck hasn't
 371                          * finished yet
 372                          */
 373                         ob = NULL;
 374                         goto err;
 375                 }
 376         }
 377
 378         ob = __try_alloc_bucket(c, ca, b, watermark, a, s, cl);
 379         if (!ob)
 380                 iter.path->preserve = false;
 381 err:
 382         if (iter.trans && iter.path)
 383                 set_btree_iter_dontneed(&iter);
 384         bch2_trans_iter_exit(trans, &iter);
 385         printbuf_exit(&buf);
 386         return ob;
 387 }
 388
 389 /*
 390  * This path is for before the freespace btree is initialized:
 391  *
 392  * If ca->new_fs_bucket_idx is nonzero, we haven't yet marked superblock &
 393  * journal buckets - journal buckets will be < ca->new_fs_bucket_idx
 394  */
 395 static noinline struct open_bucket *
 396 bch2_bucket_alloc_early(struct btree_trans *trans,
 397                         struct bch_dev *ca,
 398                         enum bch_watermark watermark,
 399                         struct bucket_alloc_state *s,
 400                         struct closure *cl)
 401 {
 402         struct btree_iter iter;
 403         struct bkey_s_c k;
 404         struct open_bucket *ob = NULL;
 405         u64 alloc_start = max_t(u64, ca->mi.first_bucket, ca->new_fs_bucket_idx);
 406         u64 alloc_cursor = max(alloc_start, READ_ONCE(ca->alloc_cursor));
 407         int ret;
 408 again:
 409         for_each_btree_key_norestart(trans, iter, BTREE_ID_alloc, POS(ca->dev_idx, alloc_cursor),
 410                            BTREE_ITER_SLOTS, k, ret) {
 411                 struct bch_alloc_v4 a_convert;
 412                 const struct bch_alloc_v4 *a;
 413
 414                 if (bkey_ge(k.k->p, POS(ca->dev_idx, ca->mi.nbuckets)))
 415                         break;
 416
 417                 if (ca->new_fs_bucket_idx &&
 418                     is_superblock_bucket(ca, k.k->p.offset))
 419                         continue;
 420
 421                 a = bch2_alloc_to_v4(k, &a_convert);
 422
 423                 if (a->data_type != BCH_DATA_free)
 424                         continue;
 425
 426                 s->buckets_seen++;
 427
 428                 ob = __try_alloc_bucket(trans->c, ca, k.k->p.offset, watermark, a, s, cl);
 429                 if (ob)
 430                         break;
 431         }
 432         bch2_trans_iter_exit(trans, &iter);
 433
 434         ca->alloc_cursor = alloc_cursor;
 435
 436         if (!ob && ret)
 437                 ob = ERR_PTR(ret);
 438
 439         if (!ob && alloc_cursor > alloc_start) {
 440                 alloc_cursor = alloc_start;
 441                 goto again;
 442         }
 443
 444         return ob;
 445 }
 446
 447 static struct open_bucket *bch2_bucket_alloc_freelist(struct btree_trans *trans,
 448                                                    struct bch_dev *ca,
 449                                                    enum bch_watermark watermark,
 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         u64 alloc_start = max_t(u64, ca->mi.first_bucket, READ_ONCE(ca->alloc_cursor));
 457         u64 alloc_cursor = alloc_start;
 458         int ret;
 459
 460         BUG_ON(ca->new_fs_bucket_idx);
 461 again:
 462         for_each_btree_key_norestart(trans, iter, BTREE_ID_freespace,
 463                                      POS(ca->dev_idx, alloc_cursor), 0, k, ret) {
 464                 if (k.k->p.inode != ca->dev_idx)
 465                         break;
 466
 467                 for (alloc_cursor = max(alloc_cursor, bkey_start_offset(k.k));
 468                      alloc_cursor < k.k->p.offset;
 469                      alloc_cursor++) {
 470                         ret = btree_trans_too_many_iters(trans);
 471                         if (ret) {
 472                                 ob = ERR_PTR(ret);
 473                                 break;
 474                         }
 475
 476                         s->buckets_seen++;
 477
 478                         ob = try_alloc_bucket(trans, ca, watermark,
 479                                               alloc_cursor, s, k, cl);
 480                         if (ob) {
 481                                 iter.path->preserve = false;
 482                                 break;
 483                         }
 484                 }
 485
 486                 if (ob || ret)
 487                         break;
 488         }
 489         bch2_trans_iter_exit(trans, &iter);
 490
 491         ca->alloc_cursor = alloc_cursor;
 492
 493         if (!ob && ret)
 494                 ob = ERR_PTR(ret);
 495
 496         if (!ob && alloc_start > ca->mi.first_bucket) {
 497                 alloc_cursor = alloc_start = ca->mi.first_bucket;
 498                 goto again;
 499         }
 500
 501         return ob;
 502 }
 503
 504 /**
 505  * bch2_bucket_alloc_trans - allocate a single bucket from a specific device
 506  * @trans:      transaction object
 507  * @ca:         device to allocate from
 508  * @watermark:  how important is this allocation?
 509  * @cl:         if not NULL, closure to be used to wait if buckets not available
 510  * @usage:      for secondarily also returning the current device usage
 511  *
 512  * Returns:     an open_bucket on success, or an ERR_PTR() on failure.
 513  */
 514 static struct open_bucket *bch2_bucket_alloc_trans(struct btree_trans *trans,
 515                                       struct bch_dev *ca,
 516                                       enum bch_watermark watermark,
 517                                       struct closure *cl,
 518                                       struct bch_dev_usage *usage)
 519 {
 520         struct bch_fs *c = trans->c;
 521         struct open_bucket *ob = NULL;
 522         bool freespace = READ_ONCE(ca->mi.freespace_initialized);
 523         u64 avail;
 524         struct bucket_alloc_state s = { 0 };
 525         bool waiting = false;
 526 again:
 527         bch2_dev_usage_read_fast(ca, usage);
 528         avail = dev_buckets_free(ca, *usage, watermark);
 529
 530         if (usage->d[BCH_DATA_need_discard].buckets > avail)
 531                 bch2_do_discards(c);
 532
 533         if (usage->d[BCH_DATA_need_gc_gens].buckets > avail)
 534                 bch2_do_gc_gens(c);
 535
 536         if (should_invalidate_buckets(ca, *usage))
 537                 bch2_do_invalidates(c);
 538
 539         if (!avail) {
 540                 if (cl && !waiting) {
 541                         closure_wait(&c->freelist_wait, cl);
 542                         waiting = true;
 543                         goto again;
 544                 }
 545
 546                 if (!c->blocked_allocate)
 547                         c->blocked_allocate = local_clock();
 548
 549                 ob = ERR_PTR(-BCH_ERR_freelist_empty);
 550                 goto err;
 551         }
 552
 553         if (waiting)
 554                 closure_wake_up(&c->freelist_wait);
 555 alloc:
 556         ob = likely(freespace)
 557                 ? bch2_bucket_alloc_freelist(trans, ca, watermark, &s, cl)
 558                 : bch2_bucket_alloc_early(trans, ca, watermark, &s, cl);
 559
 560         if (s.skipped_need_journal_commit * 2 > avail)
 561                 bch2_journal_flush_async(&c->journal, NULL);
 562
 563         if (!ob && freespace && c->curr_recovery_pass <= BCH_RECOVERY_PASS_check_alloc_info) {
 564                 freespace = false;
 565                 goto alloc;
 566         }
 567 err:
 568         if (!ob)
 569                 ob = ERR_PTR(-BCH_ERR_no_buckets_found);
 570
 571         if (!IS_ERR(ob))
 572                 trace_and_count(c, bucket_alloc, ca,
 573                                 bch2_watermarks[watermark],
 574                                 ob->bucket,
 575                                 usage->d[BCH_DATA_free].buckets,
 576                                 avail,
 577                                 bch2_copygc_wait_amount(c),
 578                                 c->copygc_wait - atomic64_read(&c->io_clock[WRITE].now),
 579                                 &s,
 580                                 cl == NULL,
 581                                 "");
 582         else if (!bch2_err_matches(PTR_ERR(ob), BCH_ERR_transaction_restart))
 583                 trace_and_count(c, bucket_alloc_fail, ca,
 584                                 bch2_watermarks[watermark],
 585                                 0,
 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 bch_watermark watermark,
 599                                       struct closure *cl)
 600 {
 601         struct bch_dev_usage usage;
 602         struct open_bucket *ob;
 603
 604         bch2_trans_do(c, NULL, NULL, 0,
 605                       PTR_ERR_OR_ZERO(ob = bch2_bucket_alloc_trans(trans, ca, watermark,
 606                                                         cl, &usage)));
 607         return ob;
 608 }
 609
 610 static int __dev_stripe_cmp(struct dev_stripe_state *stripe,
 611                             unsigned l, unsigned r)
 612 {
 613         return ((stripe->next_alloc[l] > stripe->next_alloc[r]) -
 614                 (stripe->next_alloc[l] < stripe->next_alloc[r]));
 615 }
 616
 617 #define dev_stripe_cmp(l, r) __dev_stripe_cmp(stripe, l, r)
 618
 619 struct dev_alloc_list bch2_dev_alloc_list(struct bch_fs *c,
 620                                           struct dev_stripe_state *stripe,
 621                                           struct bch_devs_mask *devs)
 622 {
 623         struct dev_alloc_list ret = { .nr = 0 };
 624         unsigned i;
 625
 626         for_each_set_bit(i, devs->d, BCH_SB_MEMBERS_MAX)
 627                 ret.devs[ret.nr++] = i;
 628
 629         bubble_sort(ret.devs, ret.nr, dev_stripe_cmp);
 630         return ret;
 631 }
 632
 633 static inline void bch2_dev_stripe_increment_inlined(struct bch_dev *ca,
 634                                struct dev_stripe_state *stripe,
 635                                struct bch_dev_usage *usage)
 636 {
 637         u64 *v = stripe->next_alloc + ca->dev_idx;
 638         u64 free_space = dev_buckets_available(ca, BCH_WATERMARK_normal);
 639         u64 free_space_inv = free_space
 640                 ? div64_u64(1ULL << 48, free_space)
 641                 : 1ULL << 48;
 642         u64 scale = *v / 4;
 643
 644         if (*v + free_space_inv >= *v)
 645                 *v += free_space_inv;
 646         else
 647                 *v = U64_MAX;
 648
 649         for (v = stripe->next_alloc;
 650              v < stripe->next_alloc + ARRAY_SIZE(stripe->next_alloc); v++)
 651                 *v = *v < scale ? 0 : *v - scale;
 652 }
 653
 654 void bch2_dev_stripe_increment(struct bch_dev *ca,
 655                                struct dev_stripe_state *stripe)
 656 {
 657         struct bch_dev_usage usage;
 658
 659         bch2_dev_usage_read_fast(ca, &usage);
 660         bch2_dev_stripe_increment_inlined(ca, stripe, &usage);
 661 }
 662
 663 static int add_new_bucket(struct bch_fs *c,
 664                            struct open_buckets *ptrs,
 665                            struct bch_devs_mask *devs_may_alloc,
 666                            unsigned nr_replicas,
 667                            unsigned *nr_effective,
 668                            bool *have_cache,
 669                            unsigned flags,
 670                            struct open_bucket *ob)
 671 {
 672         unsigned durability =
 673                 bch_dev_bkey_exists(c, ob->dev)->mi.durability;
 674
 675         BUG_ON(*nr_effective >= nr_replicas);
 676         BUG_ON(flags & BCH_WRITE_ONLY_SPECIFIED_DEVS);
 677
 678         __clear_bit(ob->dev, devs_may_alloc->d);
 679         *nr_effective   += (flags & BCH_WRITE_ONLY_SPECIFIED_DEVS)
 680                 ? durability : 1;
 681         *have_cache     |= !durability;
 682
 683         ob_push(c, ptrs, ob);
 684
 685         if (*nr_effective >= nr_replicas)
 686                 return 1;
 687         if (ob->ec)
 688                 return 1;
 689         return 0;
 690 }
 691
 692 int bch2_bucket_alloc_set_trans(struct btree_trans *trans,
 693                       struct open_buckets *ptrs,
 694                       struct dev_stripe_state *stripe,
 695                       struct bch_devs_mask *devs_may_alloc,
 696                       unsigned nr_replicas,
 697                       unsigned *nr_effective,
 698                       bool *have_cache,
 699                       unsigned flags,
 700                       enum bch_data_type data_type,
 701                       enum bch_watermark watermark,
 702                       struct closure *cl)
 703 {
 704         struct bch_fs *c = trans->c;
 705         struct dev_alloc_list devs_sorted =
 706                 bch2_dev_alloc_list(c, stripe, devs_may_alloc);
 707         unsigned dev;
 708         struct bch_dev *ca;
 709         int ret = -BCH_ERR_insufficient_devices;
 710         unsigned i;
 711
 712         BUG_ON(*nr_effective >= nr_replicas);
 713
 714         for (i = 0; i < devs_sorted.nr; i++) {
 715                 struct bch_dev_usage usage;
 716                 struct open_bucket *ob;
 717
 718                 dev = devs_sorted.devs[i];
 719
 720                 rcu_read_lock();
 721                 ca = rcu_dereference(c->devs[dev]);
 722                 if (ca)
 723                         percpu_ref_get(&ca->ref);
 724                 rcu_read_unlock();
 725
 726                 if (!ca)
 727                         continue;
 728
 729                 if (!ca->mi.durability && *have_cache) {
 730                         percpu_ref_put(&ca->ref);
 731                         continue;
 732                 }
 733
 734                 ob = bch2_bucket_alloc_trans(trans, ca, watermark, cl, &usage);
 735                 if (!IS_ERR(ob))
 736                         bch2_dev_stripe_increment_inlined(ca, stripe, &usage);
 737                 percpu_ref_put(&ca->ref);
 738
 739                 if (IS_ERR(ob)) {
 740                         ret = PTR_ERR(ob);
 741                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart) || cl)
 742                                 break;
 743                         continue;
 744                 }
 745
 746                 ob->data_type = data_type;
 747
 748                 if (add_new_bucket(c, ptrs, devs_may_alloc,
 749                                    nr_replicas, nr_effective,
 750                                    have_cache, flags, ob)) {
 751                         ret = 0;
 752                         break;
 753                 }
 754         }
 755
 756         return ret;
 757 }
 758
 759 /* Allocate from stripes: */
 760
 761 /*
 762  * if we can't allocate a new stripe because there are already too many
 763  * partially filled stripes, force allocating from an existing stripe even when
 764  * it's to a device we don't want:
 765  */
 766
 767 static int bucket_alloc_from_stripe(struct btree_trans *trans,
 768                          struct open_buckets *ptrs,
 769                          struct write_point *wp,
 770                          struct bch_devs_mask *devs_may_alloc,
 771                          u16 target,
 772                          unsigned nr_replicas,
 773                          unsigned *nr_effective,
 774                          bool *have_cache,
 775                          enum bch_watermark watermark,
 776                          unsigned flags,
 777                          struct closure *cl)
 778 {
 779         struct bch_fs *c = trans->c;
 780         struct dev_alloc_list devs_sorted;
 781         struct ec_stripe_head *h;
 782         struct open_bucket *ob;
 783         unsigned i, ec_idx;
 784         int ret = 0;
 785
 786         if (nr_replicas < 2)
 787                 return 0;
 788
 789         if (ec_open_bucket(c, ptrs))
 790                 return 0;
 791
 792         h = bch2_ec_stripe_head_get(trans, target, 0, nr_replicas - 1, watermark, cl);
 793         if (IS_ERR(h))
 794                 return PTR_ERR(h);
 795         if (!h)
 796                 return 0;
 797
 798         devs_sorted = bch2_dev_alloc_list(c, &wp->stripe, devs_may_alloc);
 799
 800         for (i = 0; i < devs_sorted.nr; i++)
 801                 for (ec_idx = 0; ec_idx < h->s->nr_data; ec_idx++) {
 802                         if (!h->s->blocks[ec_idx])
 803                                 continue;
 804
 805                         ob = c->open_buckets + h->s->blocks[ec_idx];
 806                         if (ob->dev == devs_sorted.devs[i] &&
 807                             !test_and_set_bit(ec_idx, h->s->blocks_allocated))
 808                                 goto got_bucket;
 809                 }
 810         goto out_put_head;
 811 got_bucket:
 812         ob->ec_idx      = ec_idx;
 813         ob->ec          = h->s;
 814         ec_stripe_new_get(h->s, STRIPE_REF_io);
 815
 816         ret = add_new_bucket(c, ptrs, devs_may_alloc,
 817                              nr_replicas, nr_effective,
 818                              have_cache, flags, ob);
 819 out_put_head:
 820         bch2_ec_stripe_head_put(c, h);
 821         return ret;
 822 }
 823
 824 /* Sector allocator */
 825
 826 static bool want_bucket(struct bch_fs *c,
 827                         struct write_point *wp,
 828                         struct bch_devs_mask *devs_may_alloc,
 829                         bool *have_cache, bool ec,
 830                         struct open_bucket *ob)
 831 {
 832         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
 833
 834         if (!test_bit(ob->dev, devs_may_alloc->d))
 835                 return false;
 836
 837         if (ob->data_type != wp->data_type)
 838                 return false;
 839
 840         if (!ca->mi.durability &&
 841             (wp->data_type == BCH_DATA_btree || ec || *have_cache))
 842                 return false;
 843
 844         if (ec != (ob->ec != NULL))
 845                 return false;
 846
 847         return true;
 848 }
 849
 850 static int bucket_alloc_set_writepoint(struct bch_fs *c,
 851                                        struct open_buckets *ptrs,
 852                                        struct write_point *wp,
 853                                        struct bch_devs_mask *devs_may_alloc,
 854                                        unsigned nr_replicas,
 855                                        unsigned *nr_effective,
 856                                        bool *have_cache,
 857                                        bool ec, unsigned flags)
 858 {
 859         struct open_buckets ptrs_skip = { .nr = 0 };
 860         struct open_bucket *ob;
 861         unsigned i;
 862         int ret = 0;
 863
 864         open_bucket_for_each(c, &wp->ptrs, ob, i) {
 865                 if (!ret && want_bucket(c, wp, devs_may_alloc,
 866                                         have_cache, ec, ob))
 867                         ret = add_new_bucket(c, ptrs, devs_may_alloc,
 868                                        nr_replicas, nr_effective,
 869                                        have_cache, flags, ob);
 870                 else
 871                         ob_push(c, &ptrs_skip, ob);
 872         }
 873         wp->ptrs = ptrs_skip;
 874
 875         return ret;
 876 }
 877
 878 static int bucket_alloc_set_partial(struct bch_fs *c,
 879                                     struct open_buckets *ptrs,
 880                                     struct write_point *wp,
 881                                     struct bch_devs_mask *devs_may_alloc,
 882                                     unsigned nr_replicas,
 883                                     unsigned *nr_effective,
 884                                     bool *have_cache, bool ec,
 885                                     enum bch_watermark watermark,
 886                                     unsigned flags)
 887 {
 888         int i, ret = 0;
 889
 890         if (!c->open_buckets_partial_nr)
 891                 return 0;
 892
 893         spin_lock(&c->freelist_lock);
 894
 895         if (!c->open_buckets_partial_nr)
 896                 goto unlock;
 897
 898         for (i = c->open_buckets_partial_nr - 1; i >= 0; --i) {
 899                 struct open_bucket *ob = c->open_buckets + c->open_buckets_partial[i];
 900
 901                 if (want_bucket(c, wp, devs_may_alloc, have_cache, ec, ob)) {
 902                         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
 903                         struct bch_dev_usage usage;
 904                         u64 avail;
 905
 906                         bch2_dev_usage_read_fast(ca, &usage);
 907                         avail = dev_buckets_free(ca, usage, watermark);
 908                         if (!avail)
 909                                 continue;
 910
 911                         array_remove_item(c->open_buckets_partial,
 912                                           c->open_buckets_partial_nr,
 913                                           i);
 914                         ob->on_partial_list = false;
 915
 916                         ret = add_new_bucket(c, ptrs, devs_may_alloc,
 917                                              nr_replicas, nr_effective,
 918                                              have_cache, flags, ob);
 919                         if (ret)
 920                                 break;
 921                 }
 922         }
 923 unlock:
 924         spin_unlock(&c->freelist_lock);
 925         return ret;
 926 }
 927
 928 static int __open_bucket_add_buckets(struct btree_trans *trans,
 929                         struct open_buckets *ptrs,
 930                         struct write_point *wp,
 931                         struct bch_devs_list *devs_have,
 932                         u16 target,
 933                         bool erasure_code,
 934                         unsigned nr_replicas,
 935                         unsigned *nr_effective,
 936                         bool *have_cache,
 937                         enum bch_watermark watermark,
 938                         unsigned flags,
 939                         struct closure *_cl)
 940 {
 941         struct bch_fs *c = trans->c;
 942         struct bch_devs_mask devs;
 943         struct open_bucket *ob;
 944         struct closure *cl = NULL;
 945         unsigned i;
 946         int ret;
 947
 948         devs = target_rw_devs(c, wp->data_type, target);
 949
 950         /* Don't allocate from devices we already have pointers to: */
 951         for (i = 0; i < devs_have->nr; i++)
 952                 __clear_bit(devs_have->devs[i], devs.d);
 953
 954         open_bucket_for_each(c, ptrs, ob, i)
 955                 __clear_bit(ob->dev, devs.d);
 956
 957         if (erasure_code && ec_open_bucket(c, ptrs))
 958                 return 0;
 959
 960         ret = bucket_alloc_set_writepoint(c, ptrs, wp, &devs,
 961                                  nr_replicas, nr_effective,
 962                                  have_cache, erasure_code, flags);
 963         if (ret)
 964                 return ret;
 965
 966         ret = bucket_alloc_set_partial(c, ptrs, wp, &devs,
 967                                  nr_replicas, nr_effective,
 968                                  have_cache, erasure_code, watermark, flags);
 969         if (ret)
 970                 return ret;
 971
 972         if (erasure_code) {
 973                 ret = bucket_alloc_from_stripe(trans, ptrs, wp, &devs,
 974                                          target,
 975                                          nr_replicas, nr_effective,
 976                                          have_cache,
 977                                          watermark, flags, _cl);
 978         } else {
 979 retry_blocking:
 980                 /*
 981                  * Try nonblocking first, so that if one device is full we'll try from
 982                  * other devices:
 983                  */
 984                 ret = bch2_bucket_alloc_set_trans(trans, ptrs, &wp->stripe, &devs,
 985                                         nr_replicas, nr_effective, have_cache,
 986                                         flags, wp->data_type, watermark, cl);
 987                 if (ret &&
 988                     !bch2_err_matches(ret, BCH_ERR_transaction_restart) &&
 989                     !bch2_err_matches(ret, BCH_ERR_insufficient_devices) &&
 990                     !cl && _cl) {
 991                         cl = _cl;
 992                         goto retry_blocking;
 993                 }
 994         }
 995
 996         return ret;
 997 }
 998
 999 static int open_bucket_add_buckets(struct btree_trans *trans,
1000                         struct open_buckets *ptrs,
1001                         struct write_point *wp,
1002                         struct bch_devs_list *devs_have,
1003                         u16 target,
1004                         unsigned erasure_code,
1005                         unsigned nr_replicas,
1006                         unsigned *nr_effective,
1007                         bool *have_cache,
1008                         enum bch_watermark watermark,
1009                         unsigned flags,
1010                         struct closure *cl)
1011 {
1012         int ret;
1013
1014         if (erasure_code) {
1015                 ret = __open_bucket_add_buckets(trans, ptrs, wp,
1016                                 devs_have, target, erasure_code,
1017                                 nr_replicas, nr_effective, have_cache,
1018                                 watermark, flags, cl);
1019                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
1020                     bch2_err_matches(ret, BCH_ERR_operation_blocked) ||
1021                     bch2_err_matches(ret, BCH_ERR_freelist_empty) ||
1022                     bch2_err_matches(ret, BCH_ERR_open_buckets_empty))
1023                         return ret;
1024                 if (*nr_effective >= nr_replicas)
1025                         return 0;
1026         }
1027
1028         ret = __open_bucket_add_buckets(trans, ptrs, wp,
1029                         devs_have, target, false,
1030                         nr_replicas, nr_effective, have_cache,
1031                         watermark, flags, cl);
1032         return ret < 0 ? ret : 0;
1033 }
1034
1035 /**
1036  * should_drop_bucket - check if this is open_bucket should go away
1037  * @ob:         open_bucket to predicate on
1038  * @c:          filesystem handle
1039  * @ca:         if set, we're killing buckets for a particular device
1040  * @ec:         if true, we're shutting down erasure coding and killing all ec
1041  *              open_buckets
1042  *              otherwise, return true
1043  * Returns: true if we should kill this open_bucket
1044  *
1045  * We're killing open_buckets because we're shutting down a device, erasure
1046  * coding, or the entire filesystem - check if this open_bucket matches:
1047  */
1048 static bool should_drop_bucket(struct open_bucket *ob, struct bch_fs *c,
1049                                struct bch_dev *ca, bool ec)
1050 {
1051         if (ec) {
1052                 return ob->ec != NULL;
1053         } else if (ca) {
1054                 bool drop = ob->dev == ca->dev_idx;
1055                 struct open_bucket *ob2;
1056                 unsigned i;
1057
1058                 if (!drop && ob->ec) {
1059                         unsigned nr_blocks;
1060
1061                         mutex_lock(&ob->ec->lock);
1062                         nr_blocks = bkey_i_to_stripe(&ob->ec->new_stripe.key)->v.nr_blocks;
1063
1064                         for (i = 0; i < nr_blocks; i++) {
1065                                 if (!ob->ec->blocks[i])
1066                                         continue;
1067
1068                                 ob2 = c->open_buckets + ob->ec->blocks[i];
1069                                 drop |= ob2->dev == ca->dev_idx;
1070                         }
1071                         mutex_unlock(&ob->ec->lock);
1072                 }
1073
1074                 return drop;
1075         } else {
1076                 return true;
1077         }
1078 }
1079
1080 static void bch2_writepoint_stop(struct bch_fs *c, struct bch_dev *ca,
1081                                  bool ec, struct write_point *wp)
1082 {
1083         struct open_buckets ptrs = { .nr = 0 };
1084         struct open_bucket *ob;
1085         unsigned i;
1086
1087         mutex_lock(&wp->lock);
1088         open_bucket_for_each(c, &wp->ptrs, ob, i)
1089                 if (should_drop_bucket(ob, c, ca, ec))
1090                         bch2_open_bucket_put(c, ob);
1091                 else
1092                         ob_push(c, &ptrs, ob);
1093         wp->ptrs = ptrs;
1094         mutex_unlock(&wp->lock);
1095 }
1096
1097 void bch2_open_buckets_stop(struct bch_fs *c, struct bch_dev *ca,
1098                             bool ec)
1099 {
1100         unsigned i;
1101
1102         /* Next, close write points that point to this device... */
1103         for (i = 0; i < ARRAY_SIZE(c->write_points); i++)
1104                 bch2_writepoint_stop(c, ca, ec, &c->write_points[i]);
1105
1106         bch2_writepoint_stop(c, ca, ec, &c->copygc_write_point);
1107         bch2_writepoint_stop(c, ca, ec, &c->rebalance_write_point);
1108         bch2_writepoint_stop(c, ca, ec, &c->btree_write_point);
1109
1110         mutex_lock(&c->btree_reserve_cache_lock);
1111         while (c->btree_reserve_cache_nr) {
1112                 struct btree_alloc *a =
1113                         &c->btree_reserve_cache[--c->btree_reserve_cache_nr];
1114
1115                 bch2_open_buckets_put(c, &a->ob);
1116         }
1117         mutex_unlock(&c->btree_reserve_cache_lock);
1118
1119         spin_lock(&c->freelist_lock);
1120         i = 0;
1121         while (i < c->open_buckets_partial_nr) {
1122                 struct open_bucket *ob =
1123                         c->open_buckets + c->open_buckets_partial[i];
1124
1125                 if (should_drop_bucket(ob, c, ca, ec)) {
1126                         --c->open_buckets_partial_nr;
1127                         swap(c->open_buckets_partial[i],
1128                              c->open_buckets_partial[c->open_buckets_partial_nr]);
1129                         ob->on_partial_list = false;
1130                         spin_unlock(&c->freelist_lock);
1131                         bch2_open_bucket_put(c, ob);
1132                         spin_lock(&c->freelist_lock);
1133                 } else {
1134                         i++;
1135                 }
1136         }
1137         spin_unlock(&c->freelist_lock);
1138
1139         bch2_ec_stop_dev(c, ca);
1140 }
1141
1142 static inline struct hlist_head *writepoint_hash(struct bch_fs *c,
1143                                                  unsigned long write_point)
1144 {
1145         unsigned hash =
1146                 hash_long(write_point, ilog2(ARRAY_SIZE(c->write_points_hash)));
1147
1148         return &c->write_points_hash[hash];
1149 }
1150
1151 static struct write_point *__writepoint_find(struct hlist_head *head,
1152                                              unsigned long write_point)
1153 {
1154         struct write_point *wp;
1155
1156         rcu_read_lock();
1157         hlist_for_each_entry_rcu(wp, head, node)
1158                 if (wp->write_point == write_point)
1159                         goto out;
1160         wp = NULL;
1161 out:
1162         rcu_read_unlock();
1163         return wp;
1164 }
1165
1166 static inline bool too_many_writepoints(struct bch_fs *c, unsigned factor)
1167 {
1168         u64 stranded    = c->write_points_nr * c->bucket_size_max;
1169         u64 free        = bch2_fs_usage_read_short(c).free;
1170
1171         return stranded * factor > free;
1172 }
1173
1174 static bool try_increase_writepoints(struct bch_fs *c)
1175 {
1176         struct write_point *wp;
1177
1178         if (c->write_points_nr == ARRAY_SIZE(c->write_points) ||
1179             too_many_writepoints(c, 32))
1180                 return false;
1181
1182         wp = c->write_points + c->write_points_nr++;
1183         hlist_add_head_rcu(&wp->node, writepoint_hash(c, wp->write_point));
1184         return true;
1185 }
1186
1187 static bool try_decrease_writepoints(struct btree_trans *trans, unsigned old_nr)
1188 {
1189         struct bch_fs *c = trans->c;
1190         struct write_point *wp;
1191         struct open_bucket *ob;
1192         unsigned i;
1193
1194         mutex_lock(&c->write_points_hash_lock);
1195         if (c->write_points_nr < old_nr) {
1196                 mutex_unlock(&c->write_points_hash_lock);
1197                 return true;
1198         }
1199
1200         if (c->write_points_nr == 1 ||
1201             !too_many_writepoints(c, 8)) {
1202                 mutex_unlock(&c->write_points_hash_lock);
1203                 return false;
1204         }
1205
1206         wp = c->write_points + --c->write_points_nr;
1207
1208         hlist_del_rcu(&wp->node);
1209         mutex_unlock(&c->write_points_hash_lock);
1210
1211         bch2_trans_mutex_lock_norelock(trans, &wp->lock);
1212         open_bucket_for_each(c, &wp->ptrs, ob, i)
1213                 open_bucket_free_unused(c, ob);
1214         wp->ptrs.nr = 0;
1215         mutex_unlock(&wp->lock);
1216         return true;
1217 }
1218
1219 static struct write_point *writepoint_find(struct btree_trans *trans,
1220                                            unsigned long write_point)
1221 {
1222         struct bch_fs *c = trans->c;
1223         struct write_point *wp, *oldest;
1224         struct hlist_head *head;
1225
1226         if (!(write_point & 1UL)) {
1227                 wp = (struct write_point *) write_point;
1228                 bch2_trans_mutex_lock_norelock(trans, &wp->lock);
1229                 return wp;
1230         }
1231
1232         head = writepoint_hash(c, write_point);
1233 restart_find:
1234         wp = __writepoint_find(head, write_point);
1235         if (wp) {
1236 lock_wp:
1237                 bch2_trans_mutex_lock_norelock(trans, &wp->lock);
1238                 if (wp->write_point == write_point)
1239                         goto out;
1240                 mutex_unlock(&wp->lock);
1241                 goto restart_find;
1242         }
1243 restart_find_oldest:
1244         oldest = NULL;
1245         for (wp = c->write_points;
1246              wp < c->write_points + c->write_points_nr; wp++)
1247                 if (!oldest || time_before64(wp->last_used, oldest->last_used))
1248                         oldest = wp;
1249
1250         bch2_trans_mutex_lock_norelock(trans, &oldest->lock);
1251         bch2_trans_mutex_lock_norelock(trans, &c->write_points_hash_lock);
1252         if (oldest >= c->write_points + c->write_points_nr ||
1253             try_increase_writepoints(c)) {
1254                 mutex_unlock(&c->write_points_hash_lock);
1255                 mutex_unlock(&oldest->lock);
1256                 goto restart_find_oldest;
1257         }
1258
1259         wp = __writepoint_find(head, write_point);
1260         if (wp && wp != oldest) {
1261                 mutex_unlock(&c->write_points_hash_lock);
1262                 mutex_unlock(&oldest->lock);
1263                 goto lock_wp;
1264         }
1265
1266         wp = oldest;
1267         hlist_del_rcu(&wp->node);
1268         wp->write_point = write_point;
1269         hlist_add_head_rcu(&wp->node, head);
1270         mutex_unlock(&c->write_points_hash_lock);
1271 out:
1272         wp->last_used = local_clock();
1273         return wp;
1274 }
1275
1276 /*
1277  * Get us an open_bucket we can allocate from, return with it locked:
1278  */
1279 int bch2_alloc_sectors_start_trans(struct btree_trans *trans,
1280                              unsigned target,
1281                              unsigned erasure_code,
1282                              struct write_point_specifier write_point,
1283                              struct bch_devs_list *devs_have,
1284                              unsigned nr_replicas,
1285                              unsigned nr_replicas_required,
1286                              enum bch_watermark watermark,
1287                              unsigned flags,
1288                              struct closure *cl,
1289                              struct write_point **wp_ret)
1290 {
1291         struct bch_fs *c = trans->c;
1292         struct write_point *wp;
1293         struct open_bucket *ob;
1294         struct open_buckets ptrs;
1295         unsigned nr_effective, write_points_nr;
1296         bool have_cache;
1297         int ret;
1298         int i;
1299
1300         BUG_ON(flags & BCH_WRITE_ONLY_SPECIFIED_DEVS);
1301
1302         BUG_ON(!nr_replicas || !nr_replicas_required);
1303 retry:
1304         ptrs.nr         = 0;
1305         nr_effective    = 0;
1306         write_points_nr = c->write_points_nr;
1307         have_cache      = false;
1308
1309         *wp_ret = wp = writepoint_find(trans, write_point.v);
1310
1311         /* metadata may not allocate on cache devices: */
1312         if (wp->data_type != BCH_DATA_user)
1313                 have_cache = true;
1314
1315         if (target && !(flags & BCH_WRITE_ONLY_SPECIFIED_DEVS)) {
1316                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1317                                               target, erasure_code,
1318                                               nr_replicas, &nr_effective,
1319                                               &have_cache, watermark,
1320                                               flags, NULL);
1321                 if (!ret ||
1322                     bch2_err_matches(ret, BCH_ERR_transaction_restart))
1323                         goto alloc_done;
1324
1325                 /* Don't retry from all devices if we're out of open buckets: */
1326                 if (bch2_err_matches(ret, BCH_ERR_open_buckets_empty))
1327                         goto allocate_blocking;
1328
1329                 /*
1330                  * Only try to allocate cache (durability = 0 devices) from the
1331                  * specified target:
1332                  */
1333                 have_cache = true;
1334
1335                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1336                                               0, erasure_code,
1337                                               nr_replicas, &nr_effective,
1338                                               &have_cache, watermark,
1339                                               flags, cl);
1340         } else {
1341 allocate_blocking:
1342                 ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
1343                                               target, erasure_code,
1344                                               nr_replicas, &nr_effective,
1345                                               &have_cache, watermark,
1346                                               flags, cl);
1347         }
1348 alloc_done:
1349         BUG_ON(!ret && nr_effective < nr_replicas);
1350
1351         if (erasure_code && !ec_open_bucket(c, &ptrs))
1352                 pr_debug("failed to get ec bucket: ret %u", ret);
1353
1354         if (ret == -BCH_ERR_insufficient_devices &&
1355             nr_effective >= nr_replicas_required)
1356                 ret = 0;
1357
1358         if (ret)
1359                 goto err;
1360
1361         /* Free buckets we didn't use: */
1362         open_bucket_for_each(c, &wp->ptrs, ob, i)
1363                 open_bucket_free_unused(c, ob);
1364
1365         wp->ptrs = ptrs;
1366
1367         wp->sectors_free = UINT_MAX;
1368
1369         open_bucket_for_each(c, &wp->ptrs, ob, i)
1370                 wp->sectors_free = min(wp->sectors_free, ob->sectors_free);
1371
1372         BUG_ON(!wp->sectors_free || wp->sectors_free == UINT_MAX);
1373
1374         return 0;
1375 err:
1376         open_bucket_for_each(c, &wp->ptrs, ob, i)
1377                 if (ptrs.nr < ARRAY_SIZE(ptrs.v))
1378                         ob_push(c, &ptrs, ob);
1379                 else
1380                         open_bucket_free_unused(c, ob);
1381         wp->ptrs = ptrs;
1382
1383         mutex_unlock(&wp->lock);
1384
1385         if (bch2_err_matches(ret, BCH_ERR_freelist_empty) &&
1386             try_decrease_writepoints(trans, write_points_nr))
1387                 goto retry;
1388
1389         if (bch2_err_matches(ret, BCH_ERR_open_buckets_empty) ||
1390             bch2_err_matches(ret, BCH_ERR_freelist_empty))
1391                 return cl
1392                         ? -BCH_ERR_bucket_alloc_blocked
1393                         : -BCH_ERR_ENOSPC_bucket_alloc;
1394
1395         return ret;
1396 }
1397
1398 struct bch_extent_ptr bch2_ob_ptr(struct bch_fs *c, struct open_bucket *ob)
1399 {
1400         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
1401
1402         return (struct bch_extent_ptr) {
1403                 .type   = 1 << BCH_EXTENT_ENTRY_ptr,
1404                 .gen    = ob->gen,
1405                 .dev    = ob->dev,
1406                 .offset = bucket_to_sector(ca, ob->bucket) +
1407                         ca->mi.bucket_size -
1408                         ob->sectors_free,
1409         };
1410 }
1411
1412 void bch2_alloc_sectors_append_ptrs(struct bch_fs *c, struct write_point *wp,
1413                                     struct bkey_i *k, unsigned sectors,
1414                                     bool cached)
1415 {
1416         bch2_alloc_sectors_append_ptrs_inlined(c, wp, k, sectors, cached);
1417 }
1418
1419 /*
1420  * Append pointers to the space we just allocated to @k, and mark @sectors space
1421  * as allocated out of @ob
1422  */
1423 void bch2_alloc_sectors_done(struct bch_fs *c, struct write_point *wp)
1424 {
1425         bch2_alloc_sectors_done_inlined(c, wp);
1426 }
1427
1428 static inline void writepoint_init(struct write_point *wp,
1429                                    enum bch_data_type type)
1430 {
1431         mutex_init(&wp->lock);
1432         wp->data_type = type;
1433
1434         INIT_WORK(&wp->index_update_work, bch2_write_point_do_index_updates);
1435         INIT_LIST_HEAD(&wp->writes);
1436         spin_lock_init(&wp->writes_lock);
1437 }
1438
1439 void bch2_fs_allocator_foreground_init(struct bch_fs *c)
1440 {
1441         struct open_bucket *ob;
1442         struct write_point *wp;
1443
1444         mutex_init(&c->write_points_hash_lock);
1445         c->write_points_nr = ARRAY_SIZE(c->write_points);
1446
1447         /* open bucket 0 is a sentinal NULL: */
1448         spin_lock_init(&c->open_buckets[0].lock);
1449
1450         for (ob = c->open_buckets + 1;
1451              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); ob++) {
1452                 spin_lock_init(&ob->lock);
1453                 c->open_buckets_nr_free++;
1454
1455                 ob->freelist = c->open_buckets_freelist;
1456                 c->open_buckets_freelist = ob - c->open_buckets;
1457         }
1458
1459         writepoint_init(&c->btree_write_point,          BCH_DATA_btree);
1460         writepoint_init(&c->rebalance_write_point,      BCH_DATA_user);
1461         writepoint_init(&c->copygc_write_point,         BCH_DATA_user);
1462
1463         for (wp = c->write_points;
1464              wp < c->write_points + c->write_points_nr; wp++) {
1465                 writepoint_init(wp, BCH_DATA_user);
1466
1467                 wp->last_used   = local_clock();
1468                 wp->write_point = (unsigned long) wp;
1469                 hlist_add_head_rcu(&wp->node,
1470                                    writepoint_hash(c, wp->write_point));
1471         }
1472 }
1473
1474 static void bch2_open_bucket_to_text(struct printbuf *out, struct bch_fs *c, struct open_bucket *ob)
1475 {
1476         struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
1477         unsigned data_type = ob->data_type;
1478         barrier(); /* READ_ONCE() doesn't work on bitfields */
1479
1480         prt_printf(out, "%zu ref %u %s %u:%llu gen %u allocated %u/%u",
1481                    ob - c->open_buckets,
1482                    atomic_read(&ob->pin),
1483                    data_type < BCH_DATA_NR ? bch2_data_types[data_type] : "invalid data type",
1484                    ob->dev, ob->bucket, ob->gen,
1485                    ca->mi.bucket_size - ob->sectors_free, ca->mi.bucket_size);
1486         if (ob->ec)
1487                 prt_printf(out, " ec idx %llu", ob->ec->idx);
1488         if (ob->on_partial_list)
1489                 prt_str(out, " partial");
1490         prt_newline(out);
1491 }
1492
1493 void bch2_open_buckets_to_text(struct printbuf *out, struct bch_fs *c)
1494 {
1495         struct open_bucket *ob;
1496
1497         out->atomic++;
1498
1499         for (ob = c->open_buckets;
1500              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets);
1501              ob++) {
1502                 spin_lock(&ob->lock);
1503                 if (ob->valid && !ob->on_partial_list)
1504                         bch2_open_bucket_to_text(out, c, ob);
1505                 spin_unlock(&ob->lock);
1506         }
1507
1508         --out->atomic;
1509 }
1510
1511 void bch2_open_buckets_partial_to_text(struct printbuf *out, struct bch_fs *c)
1512 {
1513         unsigned i;
1514
1515         out->atomic++;
1516         spin_lock(&c->freelist_lock);
1517
1518         for (i = 0; i < c->open_buckets_partial_nr; i++)
1519                 bch2_open_bucket_to_text(out, c,
1520                                 c->open_buckets + c->open_buckets_partial[i]);
1521
1522         spin_unlock(&c->freelist_lock);
1523         --out->atomic;
1524 }
1525
1526 static const char * const bch2_write_point_states[] = {
1527 #define x(n)    #n,
1528         WRITE_POINT_STATES()
1529 #undef x
1530         NULL
1531 };
1532
1533 static void bch2_write_point_to_text(struct printbuf *out, struct bch_fs *c,
1534                                      struct write_point *wp)
1535 {
1536         struct open_bucket *ob;
1537         unsigned i;
1538
1539         prt_printf(out, "%lu: ", wp->write_point);
1540         prt_human_readable_u64(out, wp->sectors_allocated);
1541
1542         prt_printf(out, " last wrote: ");
1543         bch2_pr_time_units(out, sched_clock() - wp->last_used);
1544
1545         for (i = 0; i < WRITE_POINT_STATE_NR; i++) {
1546                 prt_printf(out, " %s: ", bch2_write_point_states[i]);
1547                 bch2_pr_time_units(out, wp->time[i]);
1548         }
1549
1550         prt_newline(out);
1551
1552         printbuf_indent_add(out, 2);
1553         open_bucket_for_each(c, &wp->ptrs, ob, i)
1554                 bch2_open_bucket_to_text(out, c, ob);
1555         printbuf_indent_sub(out, 2);
1556 }
1557
1558 void bch2_write_points_to_text(struct printbuf *out, struct bch_fs *c)
1559 {
1560         struct write_point *wp;
1561
1562         prt_str(out, "Foreground write points\n");
1563         for (wp = c->write_points;
1564              wp < c->write_points + ARRAY_SIZE(c->write_points);
1565              wp++)
1566                 bch2_write_point_to_text(out, c, wp);
1567
1568         prt_str(out, "Copygc write point\n");
1569         bch2_write_point_to_text(out, c, &c->copygc_write_point);
1570
1571         prt_str(out, "Rebalance write point\n");
1572         bch2_write_point_to_text(out, c, &c->rebalance_write_point);
1573
1574         prt_str(out, "Btree write point\n");
1575         bch2_write_point_to_text(out, c, &c->btree_write_point);
1576 }