git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/super.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * bcachefs setup/teardown code, and some metadata io - read a superblock and
   4  * figure out what to do with it.
   5  *
   6  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
   7  * Copyright 2012 Google, Inc.
   8  */
   9
  10 #include "bcachefs.h"
  11 #include "alloc_background.h"
  12 #include "alloc_foreground.h"
  13 #include "bkey_sort.h"
  14 #include "btree_cache.h"
  15 #include "btree_gc.h"
  16 #include "btree_key_cache.h"
  17 #include "btree_update_interior.h"
  18 #include "btree_io.h"
  19 #include "buckets_waiting_for_journal.h"
  20 #include "chardev.h"
  21 #include "checksum.h"
  22 #include "clock.h"
  23 #include "compress.h"
  24 #include "debug.h"
  25 #include "disk_groups.h"
  26 #include "ec.h"
  27 #include "error.h"
  28 #include "fs.h"
  29 #include "fs-io.h"
  30 #include "fsck.h"
  31 #include "inode.h"
  32 #include "io.h"
  33 #include "journal.h"
  34 #include "journal_reclaim.h"
  35 #include "journal_seq_blacklist.h"
  36 #include "move.h"
  37 #include "migrate.h"
  38 #include "movinggc.h"
  39 #include "quota.h"
  40 #include "rebalance.h"
  41 #include "recovery.h"
  42 #include "replicas.h"
  43 #include "subvolume.h"
  44 #include "super.h"
  45 #include "super-io.h"
  46 #include "sysfs.h"
  47 #include "counters.h"
  48
  49 #include <linux/backing-dev.h>
  50 #include <linux/blkdev.h>
  51 #include <linux/debugfs.h>
  52 #include <linux/device.h>
  53 #include <linux/idr.h>
  54 #include <linux/module.h>
  55 #include <linux/percpu.h>
  56 #include <linux/pretty-printers.h>
  57 #include <linux/random.h>
  58 #include <linux/sysfs.h>
  59 #include <crypto/hash.h>
  60
  61 #include <trace/events/bcachefs.h>
  62
  63 MODULE_LICENSE("GPL");
  64 MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
  65
  66 #define KTYPE(type)                                                     \
  67 static const struct attribute_group type ## _group = {                  \
  68         .attrs = type ## _files                                         \
  69 };                                                                      \
  70                                                                         \
  71 static const struct attribute_group *type ## _groups[] = {              \
  72         &type ## _group,                                                \
  73         NULL                                                            \
  74 };                                                                      \
  75                                                                         \
  76 static const struct kobj_type type ## _ktype = {                        \
  77         .release        = type ## _release,                             \
  78         .sysfs_ops      = &type ## _sysfs_ops,                          \
  79         .default_groups = type ## _groups                               \
  80 }
  81
  82 static void bch2_fs_release(struct kobject *);
  83 static void bch2_dev_release(struct kobject *);
  84 static void bch2_fs_counters_release(struct kobject *k)
  85 {
  86 }
  87
  88 static void bch2_fs_internal_release(struct kobject *k)
  89 {
  90 }
  91
  92 static void bch2_fs_opts_dir_release(struct kobject *k)
  93 {
  94 }
  95
  96 static void bch2_fs_time_stats_release(struct kobject *k)
  97 {
  98 }
  99
 100 KTYPE(bch2_fs);
 101 KTYPE(bch2_fs_counters);
 102 KTYPE(bch2_fs_internal);
 103 KTYPE(bch2_fs_opts_dir);
 104 KTYPE(bch2_fs_time_stats);
 105 KTYPE(bch2_dev);
 106
 107 static struct kset *bcachefs_kset;
 108 static LIST_HEAD(bch_fs_list);
 109 static DEFINE_MUTEX(bch_fs_list_lock);
 110
 111 static DECLARE_WAIT_QUEUE_HEAD(bch_read_only_wait);
 112
 113 static void bch2_dev_free(struct bch_dev *);
 114 static int bch2_dev_alloc(struct bch_fs *, unsigned);
 115 static int bch2_dev_sysfs_online(struct bch_fs *, struct bch_dev *);
 116 static void __bch2_dev_read_only(struct bch_fs *, struct bch_dev *);
 117
 118 struct bch_fs *bch2_dev_to_fs(dev_t dev)
 119 {
 120         struct bch_fs *c;
 121         struct bch_dev *ca;
 122         unsigned i;
 123
 124         mutex_lock(&bch_fs_list_lock);
 125         rcu_read_lock();
 126
 127         list_for_each_entry(c, &bch_fs_list, list)
 128                 for_each_member_device_rcu(ca, c, i, NULL)
 129                         if (ca->disk_sb.bdev && ca->disk_sb.bdev->bd_dev == dev) {
 130                                 closure_get(&c->cl);
 131                                 goto found;
 132                         }
 133         c = NULL;
 134 found:
 135         rcu_read_unlock();
 136         mutex_unlock(&bch_fs_list_lock);
 137
 138         return c;
 139 }
 140
 141 static struct bch_fs *__bch2_uuid_to_fs(uuid_le uuid)
 142 {
 143         struct bch_fs *c;
 144
 145         lockdep_assert_held(&bch_fs_list_lock);
 146
 147         list_for_each_entry(c, &bch_fs_list, list)
 148                 if (!memcmp(&c->disk_sb.sb->uuid, &uuid, sizeof(uuid_le)))
 149                         return c;
 150
 151         return NULL;
 152 }
 153
 154 struct bch_fs *bch2_uuid_to_fs(uuid_le uuid)
 155 {
 156         struct bch_fs *c;
 157
 158         mutex_lock(&bch_fs_list_lock);
 159         c = __bch2_uuid_to_fs(uuid);
 160         if (c)
 161                 closure_get(&c->cl);
 162         mutex_unlock(&bch_fs_list_lock);
 163
 164         return c;
 165 }
 166
 167 static void bch2_dev_usage_journal_reserve(struct bch_fs *c)
 168 {
 169         struct bch_dev *ca;
 170         unsigned i, nr = 0, u64s =
 171                 ((sizeof(struct jset_entry_dev_usage) +
 172                   sizeof(struct jset_entry_dev_usage_type) * BCH_DATA_NR)) /
 173                 sizeof(u64);
 174
 175         rcu_read_lock();
 176         for_each_member_device_rcu(ca, c, i, NULL)
 177                 nr++;
 178         rcu_read_unlock();
 179
 180         bch2_journal_entry_res_resize(&c->journal,
 181                         &c->dev_usage_journal_res, u64s * nr);
 182 }
 183
 184 /* Filesystem RO/RW: */
 185
 186 /*
 187  * For startup/shutdown of RW stuff, the dependencies are:
 188  *
 189  * - foreground writes depend on copygc and rebalance (to free up space)
 190  *
 191  * - copygc and rebalance depend on mark and sweep gc (they actually probably
 192  *   don't because they either reserve ahead of time or don't block if
 193  *   allocations fail, but allocations can require mark and sweep gc to run
 194  *   because of generation number wraparound)
 195  *
 196  * - all of the above depends on the allocator threads
 197  *
 198  * - allocator depends on the journal (when it rewrites prios and gens)
 199  */
 200
 201 static void __bch2_fs_read_only(struct bch_fs *c)
 202 {
 203         struct bch_dev *ca;
 204         unsigned i, clean_passes = 0;
 205         u64 seq = 0;
 206
 207         bch2_rebalance_stop(c);
 208         bch2_copygc_stop(c);
 209         bch2_gc_thread_stop(c);
 210
 211         bch_verbose(c, "flushing journal and stopping allocators");
 212
 213         do {
 214                 clean_passes++;
 215
 216                 if (bch2_btree_interior_updates_flush(c) ||
 217                     bch2_journal_flush_all_pins(&c->journal) ||
 218                     bch2_btree_flush_all_writes(c) ||
 219                     seq != atomic64_read(&c->journal.seq)) {
 220                         seq = atomic64_read(&c->journal.seq);
 221                         clean_passes = 0;
 222                 }
 223         } while (clean_passes < 2);
 224
 225         bch_verbose(c, "flushing journal and stopping allocators complete");
 226
 227         if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
 228             !test_bit(BCH_FS_EMERGENCY_RO, &c->flags))
 229                 set_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
 230         bch2_fs_journal_stop(&c->journal);
 231
 232         /*
 233          * After stopping journal:
 234          */
 235         for_each_member_device(ca, c, i)
 236                 bch2_dev_allocator_remove(c, ca);
 237 }
 238
 239 static void bch2_writes_disabled(struct percpu_ref *writes)
 240 {
 241         struct bch_fs *c = container_of(writes, struct bch_fs, writes);
 242
 243         set_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
 244         wake_up(&bch_read_only_wait);
 245 }
 246
 247 void bch2_fs_read_only(struct bch_fs *c)
 248 {
 249         if (!test_bit(BCH_FS_RW, &c->flags)) {
 250                 bch2_journal_reclaim_stop(&c->journal);
 251                 return;
 252         }
 253
 254         BUG_ON(test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags));
 255
 256         /*
 257          * Block new foreground-end write operations from starting - any new
 258          * writes will return -EROFS:
 259          */
 260         percpu_ref_kill(&c->writes);
 261
 262         cancel_work_sync(&c->ec_stripe_delete_work);
 263
 264         /*
 265          * If we're not doing an emergency shutdown, we want to wait on
 266          * outstanding writes to complete so they don't see spurious errors due
 267          * to shutting down the allocator:
 268          *
 269          * If we are doing an emergency shutdown outstanding writes may
 270          * hang until we shutdown the allocator so we don't want to wait
 271          * on outstanding writes before shutting everything down - but
 272          * we do need to wait on them before returning and signalling
 273          * that going RO is complete:
 274          */
 275         wait_event(bch_read_only_wait,
 276                    test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags) ||
 277                    test_bit(BCH_FS_EMERGENCY_RO, &c->flags));
 278
 279         __bch2_fs_read_only(c);
 280
 281         wait_event(bch_read_only_wait,
 282                    test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags));
 283
 284         clear_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
 285
 286         if (!bch2_journal_error(&c->journal) &&
 287             !test_bit(BCH_FS_ERROR, &c->flags) &&
 288             !test_bit(BCH_FS_EMERGENCY_RO, &c->flags) &&
 289             test_bit(BCH_FS_STARTED, &c->flags) &&
 290             test_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags) &&
 291             !c->opts.norecovery) {
 292                 bch_verbose(c, "marking filesystem clean");
 293                 bch2_fs_mark_clean(c);
 294         }
 295
 296         clear_bit(BCH_FS_RW, &c->flags);
 297 }
 298
 299 static void bch2_fs_read_only_work(struct work_struct *work)
 300 {
 301         struct bch_fs *c =
 302                 container_of(work, struct bch_fs, read_only_work);
 303
 304         down_write(&c->state_lock);
 305         bch2_fs_read_only(c);
 306         up_write(&c->state_lock);
 307 }
 308
 309 static void bch2_fs_read_only_async(struct bch_fs *c)
 310 {
 311         queue_work(system_long_wq, &c->read_only_work);
 312 }
 313
 314 bool bch2_fs_emergency_read_only(struct bch_fs *c)
 315 {
 316         bool ret = !test_and_set_bit(BCH_FS_EMERGENCY_RO, &c->flags);
 317
 318         bch2_journal_halt(&c->journal);
 319         bch2_fs_read_only_async(c);
 320
 321         wake_up(&bch_read_only_wait);
 322         return ret;
 323 }
 324
 325 static int bch2_fs_read_write_late(struct bch_fs *c)
 326 {
 327         int ret;
 328
 329         ret = bch2_gc_thread_start(c);
 330         if (ret) {
 331                 bch_err(c, "error starting gc thread");
 332                 return ret;
 333         }
 334
 335         ret = bch2_copygc_start(c);
 336         if (ret) {
 337                 bch_err(c, "error starting copygc thread");
 338                 return ret;
 339         }
 340
 341         ret = bch2_rebalance_start(c);
 342         if (ret) {
 343                 bch_err(c, "error starting rebalance thread");
 344                 return ret;
 345         }
 346
 347         schedule_work(&c->ec_stripe_delete_work);
 348
 349         return 0;
 350 }
 351
 352 static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 353 {
 354         struct bch_dev *ca;
 355         unsigned i;
 356         int ret;
 357
 358         if (test_bit(BCH_FS_INITIAL_GC_UNFIXED, &c->flags)) {
 359                 bch_err(c, "cannot go rw, unfixed btree errors");
 360                 return -EROFS;
 361         }
 362
 363         if (test_bit(BCH_FS_RW, &c->flags))
 364                 return 0;
 365
 366         /*
 367          * nochanges is used for fsck -n mode - we have to allow going rw
 368          * during recovery for that to work:
 369          */
 370         if (c->opts.norecovery ||
 371             (c->opts.nochanges &&
 372              (!early || c->opts.read_only)))
 373                 return -EROFS;
 374
 375         bch_info(c, "going read-write");
 376
 377         ret = bch2_fs_mark_dirty(c);
 378         if (ret)
 379                 goto err;
 380
 381         clear_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
 382
 383         for_each_rw_member(ca, c, i)
 384                 bch2_dev_allocator_add(c, ca);
 385         bch2_recalc_capacity(c);
 386
 387         bch2_do_discards(c);
 388         bch2_do_invalidates(c);
 389
 390         if (!early) {
 391                 ret = bch2_fs_read_write_late(c);
 392                 if (ret)
 393                         goto err;
 394         }
 395
 396         percpu_ref_reinit(&c->writes);
 397         set_bit(BCH_FS_RW, &c->flags);
 398         set_bit(BCH_FS_WAS_RW, &c->flags);
 399         return 0;
 400 err:
 401         __bch2_fs_read_only(c);
 402         return ret;
 403 }
 404
 405 int bch2_fs_read_write(struct bch_fs *c)
 406 {
 407         return __bch2_fs_read_write(c, false);
 408 }
 409
 410 int bch2_fs_read_write_early(struct bch_fs *c)
 411 {
 412         lockdep_assert_held(&c->state_lock);
 413
 414         return __bch2_fs_read_write(c, true);
 415 }
 416
 417 /* Filesystem startup/shutdown: */
 418
 419 static void __bch2_fs_free(struct bch_fs *c)
 420 {
 421         unsigned i;
 422         int cpu;
 423
 424         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 425                 bch2_time_stats_exit(&c->times[i]);
 426
 427         bch2_fs_counters_exit(c);
 428         bch2_fs_snapshots_exit(c);
 429         bch2_fs_quota_exit(c);
 430         bch2_fs_fsio_exit(c);
 431         bch2_fs_ec_exit(c);
 432         bch2_fs_encryption_exit(c);
 433         bch2_fs_io_exit(c);
 434         bch2_fs_buckets_waiting_for_journal_exit(c);
 435         bch2_fs_btree_interior_update_exit(c);
 436         bch2_fs_btree_iter_exit(c);
 437         bch2_fs_btree_key_cache_exit(&c->btree_key_cache);
 438         bch2_fs_btree_cache_exit(c);
 439         bch2_fs_replicas_exit(c);
 440         bch2_fs_journal_exit(&c->journal);
 441         bch2_io_clock_exit(&c->io_clock[WRITE]);
 442         bch2_io_clock_exit(&c->io_clock[READ]);
 443         bch2_fs_compress_exit(c);
 444         bch2_journal_keys_free(&c->journal_keys);
 445         bch2_journal_entries_free(c);
 446         percpu_free_rwsem(&c->mark_lock);
 447
 448         if (c->btree_paths_bufs)
 449                 for_each_possible_cpu(cpu)
 450                         kfree(per_cpu_ptr(c->btree_paths_bufs, cpu)->path);
 451
 452         free_percpu(c->online_reserved);
 453         free_percpu(c->btree_paths_bufs);
 454         free_percpu(c->pcpu);
 455         mempool_exit(&c->large_bkey_pool);
 456         mempool_exit(&c->btree_bounce_pool);
 457         bioset_exit(&c->btree_bio);
 458         mempool_exit(&c->fill_iter);
 459         percpu_ref_exit(&c->writes);
 460         kfree(rcu_dereference_protected(c->disk_groups, 1));
 461         kfree(c->journal_seq_blacklist_table);
 462         kfree(c->unused_inode_hints);
 463         free_heap(&c->copygc_heap);
 464
 465         if (c->io_complete_wq )
 466                 destroy_workqueue(c->io_complete_wq );
 467         if (c->copygc_wq)
 468                 destroy_workqueue(c->copygc_wq);
 469         if (c->btree_io_complete_wq)
 470                 destroy_workqueue(c->btree_io_complete_wq);
 471         if (c->btree_update_wq)
 472                 destroy_workqueue(c->btree_update_wq);
 473
 474         bch2_free_super(&c->disk_sb);
 475         kvpfree(c, sizeof(*c));
 476         module_put(THIS_MODULE);
 477 }
 478
 479 static void bch2_fs_release(struct kobject *kobj)
 480 {
 481         struct bch_fs *c = container_of(kobj, struct bch_fs, kobj);
 482
 483         __bch2_fs_free(c);
 484 }
 485
 486 void __bch2_fs_stop(struct bch_fs *c)
 487 {
 488         struct bch_dev *ca;
 489         unsigned i;
 490
 491         bch_verbose(c, "shutting down");
 492
 493         set_bit(BCH_FS_STOPPING, &c->flags);
 494
 495         cancel_work_sync(&c->journal_seq_blacklist_gc_work);
 496
 497         down_write(&c->state_lock);
 498         bch2_fs_read_only(c);
 499         up_write(&c->state_lock);
 500
 501         for_each_member_device(ca, c, i)
 502                 if (ca->kobj.state_in_sysfs &&
 503                     ca->disk_sb.bdev)
 504                         sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
 505
 506         if (c->kobj.state_in_sysfs)
 507                 kobject_del(&c->kobj);
 508
 509         bch2_fs_debug_exit(c);
 510         bch2_fs_chardev_exit(c);
 511
 512         kobject_put(&c->counters_kobj);
 513         kobject_put(&c->time_stats);
 514         kobject_put(&c->opts_dir);
 515         kobject_put(&c->internal);
 516
 517         /* btree prefetch might have kicked off reads in the background: */
 518         bch2_btree_flush_all_reads(c);
 519
 520         for_each_member_device(ca, c, i)
 521                 cancel_work_sync(&ca->io_error_work);
 522
 523         cancel_work_sync(&c->read_only_work);
 524
 525         for (i = 0; i < c->sb.nr_devices; i++)
 526                 if (c->devs[i])
 527                         bch2_free_super(&c->devs[i]->disk_sb);
 528 }
 529
 530 void bch2_fs_free(struct bch_fs *c)
 531 {
 532         unsigned i;
 533
 534         mutex_lock(&bch_fs_list_lock);
 535         list_del(&c->list);
 536         mutex_unlock(&bch_fs_list_lock);
 537
 538         closure_sync(&c->cl);
 539         closure_debug_destroy(&c->cl);
 540
 541         for (i = 0; i < c->sb.nr_devices; i++)
 542                 if (c->devs[i])
 543                         bch2_dev_free(rcu_dereference_protected(c->devs[i], 1));
 544
 545         bch_verbose(c, "shutdown complete");
 546
 547         kobject_put(&c->kobj);
 548 }
 549
 550 void bch2_fs_stop(struct bch_fs *c)
 551 {
 552         __bch2_fs_stop(c);
 553         bch2_fs_free(c);
 554 }
 555
 556 static int bch2_fs_online(struct bch_fs *c)
 557 {
 558         struct bch_dev *ca;
 559         unsigned i;
 560         int ret = 0;
 561
 562         lockdep_assert_held(&bch_fs_list_lock);
 563
 564         if (__bch2_uuid_to_fs(c->sb.uuid)) {
 565                 bch_err(c, "filesystem UUID already open");
 566                 return -EINVAL;
 567         }
 568
 569         ret = bch2_fs_chardev_init(c);
 570         if (ret) {
 571                 bch_err(c, "error creating character device");
 572                 return ret;
 573         }
 574
 575         bch2_fs_debug_init(c);
 576
 577         ret = kobject_add(&c->kobj, NULL, "%pU", c->sb.user_uuid.b) ?:
 578             kobject_add(&c->internal, &c->kobj, "internal") ?:
 579             kobject_add(&c->opts_dir, &c->kobj, "options") ?:
 580             kobject_add(&c->time_stats, &c->kobj, "time_stats") ?:
 581             kobject_add(&c->counters_kobj, &c->kobj, "counters") ?:
 582             bch2_opts_create_sysfs_files(&c->opts_dir);
 583         if (ret) {
 584                 bch_err(c, "error creating sysfs objects");
 585                 return ret;
 586         }
 587
 588         down_write(&c->state_lock);
 589
 590         for_each_member_device(ca, c, i) {
 591                 ret = bch2_dev_sysfs_online(c, ca);
 592                 if (ret) {
 593                         bch_err(c, "error creating sysfs objects");
 594                         percpu_ref_put(&ca->ref);
 595                         goto err;
 596                 }
 597         }
 598
 599         BUG_ON(!list_empty(&c->list));
 600         list_add(&c->list, &bch_fs_list);
 601 err:
 602         up_write(&c->state_lock);
 603         return ret;
 604 }
 605
 606 static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 607 {
 608         struct bch_sb_field_members *mi;
 609         struct bch_fs *c;
 610         struct printbuf name = PRINTBUF;
 611         unsigned i, iter_size;
 612         int ret = 0;
 613
 614         pr_verbose_init(opts, "");
 615
 616         c = kvpmalloc(sizeof(struct bch_fs), GFP_KERNEL|__GFP_ZERO);
 617         if (!c) {
 618                 c = ERR_PTR(-ENOMEM);
 619                 goto out;
 620         }
 621
 622         __module_get(THIS_MODULE);
 623
 624         closure_init(&c->cl, NULL);
 625
 626         c->kobj.kset = bcachefs_kset;
 627         kobject_init(&c->kobj, &bch2_fs_ktype);
 628         kobject_init(&c->internal, &bch2_fs_internal_ktype);
 629         kobject_init(&c->opts_dir, &bch2_fs_opts_dir_ktype);
 630         kobject_init(&c->time_stats, &bch2_fs_time_stats_ktype);
 631         kobject_init(&c->counters_kobj, &bch2_fs_counters_ktype);
 632
 633         c->minor                = -1;
 634         c->disk_sb.fs_sb        = true;
 635
 636         init_rwsem(&c->state_lock);
 637         mutex_init(&c->sb_lock);
 638         mutex_init(&c->replicas_gc_lock);
 639         mutex_init(&c->btree_root_lock);
 640         INIT_WORK(&c->read_only_work, bch2_fs_read_only_work);
 641
 642         init_rwsem(&c->gc_lock);
 643         mutex_init(&c->gc_gens_lock);
 644
 645         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 646                 bch2_time_stats_init(&c->times[i]);
 647
 648         bch2_fs_copygc_init(c);
 649         bch2_fs_btree_key_cache_init_early(&c->btree_key_cache);
 650         bch2_fs_allocator_background_init(c);
 651         bch2_fs_allocator_foreground_init(c);
 652         bch2_fs_rebalance_init(c);
 653         bch2_fs_quota_init(c);
 654         bch2_fs_ec_init_early(c);
 655
 656         INIT_LIST_HEAD(&c->list);
 657
 658         mutex_init(&c->usage_scratch_lock);
 659
 660         mutex_init(&c->bio_bounce_pages_lock);
 661         mutex_init(&c->snapshot_table_lock);
 662
 663         spin_lock_init(&c->btree_write_error_lock);
 664
 665         INIT_WORK(&c->journal_seq_blacklist_gc_work,
 666                   bch2_blacklist_entries_gc);
 667
 668         INIT_LIST_HEAD(&c->journal_iters);
 669
 670         INIT_LIST_HEAD(&c->fsck_errors);
 671         mutex_init(&c->fsck_error_lock);
 672
 673         INIT_LIST_HEAD(&c->ec_stripe_head_list);
 674         mutex_init(&c->ec_stripe_head_lock);
 675
 676         INIT_LIST_HEAD(&c->ec_stripe_new_list);
 677         mutex_init(&c->ec_stripe_new_lock);
 678
 679         INIT_LIST_HEAD(&c->data_progress_list);
 680         mutex_init(&c->data_progress_lock);
 681
 682         spin_lock_init(&c->ec_stripes_heap_lock);
 683
 684         seqcount_init(&c->gc_pos_lock);
 685
 686         seqcount_init(&c->usage_lock);
 687
 688         sema_init(&c->io_in_flight, 64);
 689
 690         c->copy_gc_enabled              = 1;
 691         c->rebalance.enabled            = 1;
 692         c->promote_whole_extents        = true;
 693
 694         c->journal.flush_write_time     = &c->times[BCH_TIME_journal_flush_write];
 695         c->journal.noflush_write_time   = &c->times[BCH_TIME_journal_noflush_write];
 696         c->journal.blocked_time         = &c->times[BCH_TIME_blocked_journal];
 697         c->journal.flush_seq_time       = &c->times[BCH_TIME_journal_flush_seq];
 698
 699         bch2_fs_btree_cache_init_early(&c->btree_cache);
 700
 701         mutex_init(&c->sectors_available_lock);
 702
 703         ret = percpu_init_rwsem(&c->mark_lock);
 704         if (ret)
 705                 goto err;
 706
 707         mutex_lock(&c->sb_lock);
 708         ret = bch2_sb_to_fs(c, sb);
 709         mutex_unlock(&c->sb_lock);
 710
 711         if (ret)
 712                 goto err;
 713
 714         pr_uuid(&name, c->sb.user_uuid.b);
 715         strlcpy(c->name, name.buf, sizeof(c->name));
 716         printbuf_exit(&name);
 717
 718         ret = name.allocation_failure ? -ENOMEM : 0;
 719         if (ret)
 720                 goto err;
 721
 722         /* Compat: */
 723         if (sb->version <= bcachefs_metadata_version_inode_v2 &&
 724             !BCH_SB_JOURNAL_FLUSH_DELAY(sb))
 725                 SET_BCH_SB_JOURNAL_FLUSH_DELAY(sb, 1000);
 726
 727         if (sb->version <= bcachefs_metadata_version_inode_v2 &&
 728             !BCH_SB_JOURNAL_RECLAIM_DELAY(sb))
 729                 SET_BCH_SB_JOURNAL_RECLAIM_DELAY(sb, 100);
 730
 731         c->opts = bch2_opts_default;
 732         ret = bch2_opts_from_sb(&c->opts, sb);
 733         if (ret)
 734                 goto err;
 735
 736         bch2_opts_apply(&c->opts, opts);
 737
 738         /* key cache currently disabled for inodes, because of snapshots: */
 739         c->opts.inodes_use_key_cache = 0;
 740
 741         c->btree_key_cache_btrees |= 1U << BTREE_ID_alloc;
 742         if (c->opts.inodes_use_key_cache)
 743                 c->btree_key_cache_btrees |= 1U << BTREE_ID_inodes;
 744
 745         c->block_bits           = ilog2(block_sectors(c));
 746         c->btree_foreground_merge_threshold = BTREE_FOREGROUND_MERGE_THRESHOLD(c);
 747
 748         if (bch2_fs_init_fault("fs_alloc")) {
 749                 bch_err(c, "fs_alloc fault injected");
 750                 ret = -EFAULT;
 751                 goto err;
 752         }
 753
 754         iter_size = sizeof(struct sort_iter) +
 755                 (btree_blocks(c) + 1) * 2 *
 756                 sizeof(struct sort_iter_set);
 757
 758         c->inode_shard_bits = ilog2(roundup_pow_of_two(num_possible_cpus()));
 759
 760         if (!(c->btree_update_wq = alloc_workqueue("bcachefs",
 761                                 WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
 762             !(c->btree_io_complete_wq = alloc_workqueue("bcachefs_btree_io",
 763                                 WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
 764             !(c->copygc_wq = alloc_workqueue("bcachefs_copygc",
 765                                 WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
 766             !(c->io_complete_wq = alloc_workqueue("bcachefs_io",
 767                                 WQ_FREEZABLE|WQ_HIGHPRI|WQ_MEM_RECLAIM, 1)) ||
 768             percpu_ref_init(&c->writes, bch2_writes_disabled,
 769                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
 770             mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
 771             bioset_init(&c->btree_bio, 1,
 772                         max(offsetof(struct btree_read_bio, bio),
 773                             offsetof(struct btree_write_bio, wbio.bio)),
 774                         BIOSET_NEED_BVECS) ||
 775             !(c->pcpu = alloc_percpu(struct bch_fs_pcpu)) ||
 776             !(c->btree_paths_bufs = alloc_percpu(struct btree_path_buf)) ||
 777             !(c->online_reserved = alloc_percpu(u64)) ||
 778             mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
 779                                         btree_bytes(c)) ||
 780             mempool_init_kmalloc_pool(&c->large_bkey_pool, 1, 2048) ||
 781             !(c->unused_inode_hints = kcalloc(1U << c->inode_shard_bits,
 782                                               sizeof(u64), GFP_KERNEL))) {
 783                 ret = -ENOMEM;
 784                 goto err;
 785         }
 786
 787         ret = bch2_io_clock_init(&c->io_clock[READ]) ?:
 788             bch2_io_clock_init(&c->io_clock[WRITE]) ?:
 789             bch2_fs_journal_init(&c->journal) ?:
 790             bch2_fs_replicas_init(c) ?:
 791             bch2_fs_btree_cache_init(c) ?:
 792             bch2_fs_btree_key_cache_init(&c->btree_key_cache) ?:
 793             bch2_fs_btree_iter_init(c) ?:
 794             bch2_fs_btree_interior_update_init(c) ?:
 795             bch2_fs_buckets_waiting_for_journal_init(c) ?:
 796             bch2_fs_subvolumes_init(c) ?:
 797             bch2_fs_io_init(c) ?:
 798             bch2_fs_encryption_init(c) ?:
 799             bch2_fs_compress_init(c) ?:
 800             bch2_fs_ec_init(c) ?:
 801             bch2_fs_fsio_init(c) ?:
 802             bch2_fs_counters_init(c);
 803         if (ret)
 804                 goto err;
 805
 806         mi = bch2_sb_get_members(c->disk_sb.sb);
 807         for (i = 0; i < c->sb.nr_devices; i++)
 808                 if (bch2_dev_exists(c->disk_sb.sb, mi, i) &&
 809                     bch2_dev_alloc(c, i)) {
 810                         ret = -EEXIST;
 811                         goto err;
 812                 }
 813
 814         bch2_journal_entry_res_resize(&c->journal,
 815                         &c->btree_root_journal_res,
 816                         BTREE_ID_NR * (JSET_KEYS_U64s + BKEY_BTREE_PTR_U64s_MAX));
 817         bch2_dev_usage_journal_reserve(c);
 818         bch2_journal_entry_res_resize(&c->journal,
 819                         &c->clock_journal_res,
 820                         (sizeof(struct jset_entry_clock) / sizeof(u64)) * 2);
 821
 822         mutex_lock(&bch_fs_list_lock);
 823         ret = bch2_fs_online(c);
 824         mutex_unlock(&bch_fs_list_lock);
 825
 826         if (ret)
 827                 goto err;
 828 out:
 829         pr_verbose_init(opts, "ret %i", PTR_ERR_OR_ZERO(c));
 830         return c;
 831 err:
 832         bch2_fs_free(c);
 833         c = ERR_PTR(ret);
 834         goto out;
 835 }
 836
 837 noinline_for_stack
 838 static void print_mount_opts(struct bch_fs *c)
 839 {
 840         enum bch_opt_id i;
 841         struct printbuf p = PRINTBUF;
 842         bool first = true;
 843
 844         if (c->opts.read_only) {
 845                 prt_printf(&p, "ro");
 846                 first = false;
 847         }
 848
 849         for (i = 0; i < bch2_opts_nr; i++) {
 850                 const struct bch_option *opt = &bch2_opt_table[i];
 851                 u64 v = bch2_opt_get_by_id(&c->opts, i);
 852
 853                 if (!(opt->flags & OPT_MOUNT))
 854                         continue;
 855
 856                 if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
 857                         continue;
 858
 859                 if (!first)
 860                         prt_printf(&p, ",");
 861                 first = false;
 862                 bch2_opt_to_text(&p, c, c->disk_sb.sb, opt, v, OPT_SHOW_MOUNT_STYLE);
 863         }
 864
 865         if (!p.pos)
 866                 prt_printf(&p, "(null)");
 867
 868         bch_info(c, "mounted version=%s opts=%s", bch2_metadata_versions[c->sb.version], p.buf);
 869         printbuf_exit(&p);
 870 }
 871
 872 int bch2_fs_start(struct bch_fs *c)
 873 {
 874         struct bch_sb_field_members *mi;
 875         struct bch_dev *ca;
 876         time64_t now = ktime_get_real_seconds();
 877         unsigned i;
 878         int ret = -EINVAL;
 879
 880         down_write(&c->state_lock);
 881
 882         BUG_ON(test_bit(BCH_FS_STARTED, &c->flags));
 883
 884         mutex_lock(&c->sb_lock);
 885
 886         for_each_online_member(ca, c, i)
 887                 bch2_sb_from_fs(c, ca);
 888
 889         mi = bch2_sb_get_members(c->disk_sb.sb);
 890         for_each_online_member(ca, c, i)
 891                 mi->members[ca->dev_idx].last_mount = cpu_to_le64(now);
 892
 893         mutex_unlock(&c->sb_lock);
 894
 895         for_each_rw_member(ca, c, i)
 896                 bch2_dev_allocator_add(c, ca);
 897         bch2_recalc_capacity(c);
 898
 899         ret = BCH_SB_INITIALIZED(c->disk_sb.sb)
 900                 ? bch2_fs_recovery(c)
 901                 : bch2_fs_initialize(c);
 902         if (ret)
 903                 goto err;
 904
 905         ret = bch2_opts_check_may_set(c);
 906         if (ret)
 907                 goto err;
 908
 909         ret = -EINVAL;
 910         if (bch2_fs_init_fault("fs_start")) {
 911                 bch_err(c, "fs_start fault injected");
 912                 goto err;
 913         }
 914
 915         set_bit(BCH_FS_STARTED, &c->flags);
 916
 917         if (c->opts.read_only || c->opts.nochanges) {
 918                 bch2_fs_read_only(c);
 919         } else {
 920                 ret = !test_bit(BCH_FS_RW, &c->flags)
 921                         ? bch2_fs_read_write(c)
 922                         : bch2_fs_read_write_late(c);
 923                 if (ret)
 924                         goto err;
 925         }
 926
 927         print_mount_opts(c);
 928         ret = 0;
 929 out:
 930         up_write(&c->state_lock);
 931         return ret;
 932 err:
 933         switch (ret) {
 934         case BCH_FSCK_ERRORS_NOT_FIXED:
 935                 bch_err(c, "filesystem contains errors: please report this to the developers");
 936                 pr_cont("mount with -o fix_errors to repair\n");
 937                 break;
 938         case BCH_FSCK_REPAIR_UNIMPLEMENTED:
 939                 bch_err(c, "filesystem contains errors: please report this to the developers");
 940                 pr_cont("repair unimplemented: inform the developers so that it can be added\n");
 941                 break;
 942         case BCH_FSCK_REPAIR_IMPOSSIBLE:
 943                 bch_err(c, "filesystem contains errors, but repair impossible");
 944                 break;
 945         case BCH_FSCK_UNKNOWN_VERSION:
 946                 bch_err(c, "unknown metadata version");
 947                 break;
 948         case -ENOMEM:
 949                 bch_err(c, "cannot allocate memory");
 950                 break;
 951         case -EIO:
 952                 bch_err(c, "IO error");
 953                 break;
 954         }
 955
 956         if (ret >= 0)
 957                 ret = -EIO;
 958         goto out;
 959 }
 960
 961 static const char *bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
 962 {
 963         struct bch_sb_field_members *sb_mi;
 964
 965         sb_mi = bch2_sb_get_members(sb);
 966         if (!sb_mi)
 967                 return "Invalid superblock: member info area missing";
 968
 969         if (le16_to_cpu(sb->block_size) != block_sectors(c))
 970                 return "mismatched block size";
 971
 972         if (le16_to_cpu(sb_mi->members[sb->dev_idx].bucket_size) <
 973             BCH_SB_BTREE_NODE_SIZE(c->disk_sb.sb))
 974                 return "new cache bucket size is too small";
 975
 976         return NULL;
 977 }
 978
 979 static const char *bch2_dev_in_fs(struct bch_sb *fs, struct bch_sb *sb)
 980 {
 981         struct bch_sb *newest =
 982                 le64_to_cpu(fs->seq) > le64_to_cpu(sb->seq) ? fs : sb;
 983         struct bch_sb_field_members *mi = bch2_sb_get_members(newest);
 984
 985         if (uuid_le_cmp(fs->uuid, sb->uuid))
 986                 return "device not a member of filesystem";
 987
 988         if (!bch2_dev_exists(newest, mi, sb->dev_idx))
 989                 return "device has been removed";
 990
 991         if (fs->block_size != sb->block_size)
 992                 return "mismatched block size";
 993
 994         return NULL;
 995 }
 996
 997 /* Device startup/shutdown: */
 998
 999 static void bch2_dev_release(struct kobject *kobj)
1000 {
1001         struct bch_dev *ca = container_of(kobj, struct bch_dev, kobj);
1002
1003         kfree(ca);
1004 }
1005
1006 static void bch2_dev_free(struct bch_dev *ca)
1007 {
1008         cancel_work_sync(&ca->io_error_work);
1009
1010         if (ca->kobj.state_in_sysfs &&
1011             ca->disk_sb.bdev)
1012                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1013
1014         if (ca->kobj.state_in_sysfs)
1015                 kobject_del(&ca->kobj);
1016
1017         bch2_free_super(&ca->disk_sb);
1018         bch2_dev_journal_exit(ca);
1019
1020         free_percpu(ca->io_done);
1021         bioset_exit(&ca->replica_set);
1022         bch2_dev_buckets_free(ca);
1023         free_page((unsigned long) ca->sb_read_scratch);
1024
1025         bch2_time_stats_exit(&ca->io_latency[WRITE]);
1026         bch2_time_stats_exit(&ca->io_latency[READ]);
1027
1028         percpu_ref_exit(&ca->io_ref);
1029         percpu_ref_exit(&ca->ref);
1030         kobject_put(&ca->kobj);
1031 }
1032
1033 static void __bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca)
1034 {
1035
1036         lockdep_assert_held(&c->state_lock);
1037
1038         if (percpu_ref_is_zero(&ca->io_ref))
1039                 return;
1040
1041         __bch2_dev_read_only(c, ca);
1042
1043         reinit_completion(&ca->io_ref_completion);
1044         percpu_ref_kill(&ca->io_ref);
1045         wait_for_completion(&ca->io_ref_completion);
1046
1047         if (ca->kobj.state_in_sysfs) {
1048                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1049                 sysfs_remove_link(&ca->kobj, "block");
1050         }
1051
1052         bch2_free_super(&ca->disk_sb);
1053         bch2_dev_journal_exit(ca);
1054 }
1055
1056 static void bch2_dev_ref_complete(struct percpu_ref *ref)
1057 {
1058         struct bch_dev *ca = container_of(ref, struct bch_dev, ref);
1059
1060         complete(&ca->ref_completion);
1061 }
1062
1063 static void bch2_dev_io_ref_complete(struct percpu_ref *ref)
1064 {
1065         struct bch_dev *ca = container_of(ref, struct bch_dev, io_ref);
1066
1067         complete(&ca->io_ref_completion);
1068 }
1069
1070 static int bch2_dev_sysfs_online(struct bch_fs *c, struct bch_dev *ca)
1071 {
1072         int ret;
1073
1074         if (!c->kobj.state_in_sysfs)
1075                 return 0;
1076
1077         if (!ca->kobj.state_in_sysfs) {
1078                 ret = kobject_add(&ca->kobj, &c->kobj,
1079                                   "dev-%u", ca->dev_idx);
1080                 if (ret)
1081                         return ret;
1082         }
1083
1084         if (ca->disk_sb.bdev) {
1085                 struct kobject *block = bdev_kobj(ca->disk_sb.bdev);
1086
1087                 ret = sysfs_create_link(block, &ca->kobj, "bcachefs");
1088                 if (ret)
1089                         return ret;
1090
1091                 ret = sysfs_create_link(&ca->kobj, block, "block");
1092                 if (ret)
1093                         return ret;
1094         }
1095
1096         return 0;
1097 }
1098
1099 static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
1100                                         struct bch_member *member)
1101 {
1102         struct bch_dev *ca;
1103
1104         ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1105         if (!ca)
1106                 return NULL;
1107
1108         kobject_init(&ca->kobj, &bch2_dev_ktype);
1109         init_completion(&ca->ref_completion);
1110         init_completion(&ca->io_ref_completion);
1111
1112         init_rwsem(&ca->bucket_lock);
1113
1114         INIT_WORK(&ca->io_error_work, bch2_io_error_work);
1115
1116         bch2_time_stats_init(&ca->io_latency[READ]);
1117         bch2_time_stats_init(&ca->io_latency[WRITE]);
1118
1119         ca->mi = bch2_mi_to_cpu(member);
1120         ca->uuid = member->uuid;
1121
1122         ca->nr_btree_reserve = DIV_ROUND_UP(BTREE_NODE_RESERVE,
1123                              ca->mi.bucket_size / btree_sectors(c));
1124
1125         if (percpu_ref_init(&ca->ref, bch2_dev_ref_complete,
1126                             0, GFP_KERNEL) ||
1127             percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
1128                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
1129             !(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
1130             bch2_dev_buckets_alloc(c, ca) ||
1131             bioset_init(&ca->replica_set, 4,
1132                         offsetof(struct bch_write_bio, bio), 0) ||
1133             !(ca->io_done       = alloc_percpu(*ca->io_done)))
1134                 goto err;
1135
1136         return ca;
1137 err:
1138         bch2_dev_free(ca);
1139         return NULL;
1140 }
1141
1142 static void bch2_dev_attach(struct bch_fs *c, struct bch_dev *ca,
1143                             unsigned dev_idx)
1144 {
1145         ca->dev_idx = dev_idx;
1146         __set_bit(ca->dev_idx, ca->self.d);
1147         scnprintf(ca->name, sizeof(ca->name), "dev-%u", dev_idx);
1148
1149         ca->fs = c;
1150         rcu_assign_pointer(c->devs[ca->dev_idx], ca);
1151
1152         if (bch2_dev_sysfs_online(c, ca))
1153                 pr_warn("error creating sysfs objects");
1154 }
1155
1156 static int bch2_dev_alloc(struct bch_fs *c, unsigned dev_idx)
1157 {
1158         struct bch_member *member =
1159                 bch2_sb_get_members(c->disk_sb.sb)->members + dev_idx;
1160         struct bch_dev *ca = NULL;
1161         int ret = 0;
1162
1163         pr_verbose_init(c->opts, "");
1164
1165         if (bch2_fs_init_fault("dev_alloc"))
1166                 goto err;
1167
1168         ca = __bch2_dev_alloc(c, member);
1169         if (!ca)
1170                 goto err;
1171
1172         ca->fs = c;
1173
1174         bch2_dev_attach(c, ca, dev_idx);
1175 out:
1176         pr_verbose_init(c->opts, "ret %i", ret);
1177         return ret;
1178 err:
1179         if (ca)
1180                 bch2_dev_free(ca);
1181         ret = -ENOMEM;
1182         goto out;
1183 }
1184
1185 static int __bch2_dev_attach_bdev(struct bch_dev *ca, struct bch_sb_handle *sb)
1186 {
1187         unsigned ret;
1188
1189         if (bch2_dev_is_online(ca)) {
1190                 bch_err(ca, "already have device online in slot %u",
1191                         sb->sb->dev_idx);
1192                 return -EINVAL;
1193         }
1194
1195         if (get_capacity(sb->bdev->bd_disk) <
1196             ca->mi.bucket_size * ca->mi.nbuckets) {
1197                 bch_err(ca, "cannot online: device too small");
1198                 return -EINVAL;
1199         }
1200
1201         BUG_ON(!percpu_ref_is_zero(&ca->io_ref));
1202
1203         if (get_capacity(sb->bdev->bd_disk) <
1204             ca->mi.bucket_size * ca->mi.nbuckets) {
1205                 bch_err(ca, "device too small");
1206                 return -EINVAL;
1207         }
1208
1209         ret = bch2_dev_journal_init(ca, sb->sb);
1210         if (ret)
1211                 return ret;
1212
1213         /* Commit: */
1214         ca->disk_sb = *sb;
1215         if (sb->mode & FMODE_EXCL)
1216                 ca->disk_sb.bdev->bd_holder = ca;
1217         memset(sb, 0, sizeof(*sb));
1218
1219         ca->dev = ca->disk_sb.bdev->bd_dev;
1220
1221         percpu_ref_reinit(&ca->io_ref);
1222
1223         return 0;
1224 }
1225
1226 static int bch2_dev_attach_bdev(struct bch_fs *c, struct bch_sb_handle *sb)
1227 {
1228         struct bch_dev *ca;
1229         int ret;
1230
1231         lockdep_assert_held(&c->state_lock);
1232
1233         if (le64_to_cpu(sb->sb->seq) >
1234             le64_to_cpu(c->disk_sb.sb->seq))
1235                 bch2_sb_to_fs(c, sb->sb);
1236
1237         BUG_ON(sb->sb->dev_idx >= c->sb.nr_devices ||
1238                !c->devs[sb->sb->dev_idx]);
1239
1240         ca = bch_dev_locked(c, sb->sb->dev_idx);
1241
1242         ret = __bch2_dev_attach_bdev(ca, sb);
1243         if (ret)
1244                 return ret;
1245
1246         bch2_dev_sysfs_online(c, ca);
1247
1248         if (c->sb.nr_devices == 1)
1249                 bdevname(ca->disk_sb.bdev, c->name);
1250         bdevname(ca->disk_sb.bdev, ca->name);
1251
1252         rebalance_wakeup(c);
1253         return 0;
1254 }
1255
1256 /* Device management: */
1257
1258 /*
1259  * Note: this function is also used by the error paths - when a particular
1260  * device sees an error, we call it to determine whether we can just set the
1261  * device RO, or - if this function returns false - we'll set the whole
1262  * filesystem RO:
1263  *
1264  * XXX: maybe we should be more explicit about whether we're changing state
1265  * because we got an error or what have you?
1266  */
1267 bool bch2_dev_state_allowed(struct bch_fs *c, struct bch_dev *ca,
1268                             enum bch_member_state new_state, int flags)
1269 {
1270         struct bch_devs_mask new_online_devs;
1271         struct bch_dev *ca2;
1272         int i, nr_rw = 0, required;
1273
1274         lockdep_assert_held(&c->state_lock);
1275
1276         switch (new_state) {
1277         case BCH_MEMBER_STATE_rw:
1278                 return true;
1279         case BCH_MEMBER_STATE_ro:
1280                 if (ca->mi.state != BCH_MEMBER_STATE_rw)
1281                         return true;
1282
1283                 /* do we have enough devices to write to?  */
1284                 for_each_member_device(ca2, c, i)
1285                         if (ca2 != ca)
1286                                 nr_rw += ca2->mi.state == BCH_MEMBER_STATE_rw;
1287
1288                 required = max(!(flags & BCH_FORCE_IF_METADATA_DEGRADED)
1289                                ? c->opts.metadata_replicas
1290                                : c->opts.metadata_replicas_required,
1291                                !(flags & BCH_FORCE_IF_DATA_DEGRADED)
1292                                ? c->opts.data_replicas
1293                                : c->opts.data_replicas_required);
1294
1295                 return nr_rw >= required;
1296         case BCH_MEMBER_STATE_failed:
1297         case BCH_MEMBER_STATE_spare:
1298                 if (ca->mi.state != BCH_MEMBER_STATE_rw &&
1299                     ca->mi.state != BCH_MEMBER_STATE_ro)
1300                         return true;
1301
1302                 /* do we have enough devices to read from?  */
1303                 new_online_devs = bch2_online_devs(c);
1304                 __clear_bit(ca->dev_idx, new_online_devs.d);
1305
1306                 return bch2_have_enough_devs(c, new_online_devs, flags, false);
1307         default:
1308                 BUG();
1309         }
1310 }
1311
1312 static bool bch2_fs_may_start(struct bch_fs *c)
1313 {
1314         struct bch_sb_field_members *mi;
1315         struct bch_dev *ca;
1316         unsigned i, flags = 0;
1317
1318         if (c->opts.very_degraded)
1319                 flags |= BCH_FORCE_IF_DEGRADED|BCH_FORCE_IF_LOST;
1320
1321         if (c->opts.degraded)
1322                 flags |= BCH_FORCE_IF_DEGRADED;
1323
1324         if (!c->opts.degraded &&
1325             !c->opts.very_degraded) {
1326                 mutex_lock(&c->sb_lock);
1327                 mi = bch2_sb_get_members(c->disk_sb.sb);
1328
1329                 for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
1330                         if (!bch2_dev_exists(c->disk_sb.sb, mi, i))
1331                                 continue;
1332
1333                         ca = bch_dev_locked(c, i);
1334
1335                         if (!bch2_dev_is_online(ca) &&
1336                             (ca->mi.state == BCH_MEMBER_STATE_rw ||
1337                              ca->mi.state == BCH_MEMBER_STATE_ro)) {
1338                                 mutex_unlock(&c->sb_lock);
1339                                 return false;
1340                         }
1341                 }
1342                 mutex_unlock(&c->sb_lock);
1343         }
1344
1345         return bch2_have_enough_devs(c, bch2_online_devs(c), flags, true);
1346 }
1347
1348 static void __bch2_dev_read_only(struct bch_fs *c, struct bch_dev *ca)
1349 {
1350         /*
1351          * Device going read only means the copygc reserve get smaller, so we
1352          * don't want that happening while copygc is in progress:
1353          */
1354         bch2_copygc_stop(c);
1355
1356         /*
1357          * The allocator thread itself allocates btree nodes, so stop it first:
1358          */
1359         bch2_dev_allocator_remove(c, ca);
1360         bch2_dev_journal_stop(&c->journal, ca);
1361
1362         bch2_copygc_start(c);
1363 }
1364
1365 static void __bch2_dev_read_write(struct bch_fs *c, struct bch_dev *ca)
1366 {
1367         lockdep_assert_held(&c->state_lock);
1368
1369         BUG_ON(ca->mi.state != BCH_MEMBER_STATE_rw);
1370
1371         bch2_dev_allocator_add(c, ca);
1372         bch2_recalc_capacity(c);
1373 }
1374
1375 int __bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1376                          enum bch_member_state new_state, int flags)
1377 {
1378         struct bch_sb_field_members *mi;
1379         int ret = 0;
1380
1381         if (ca->mi.state == new_state)
1382                 return 0;
1383
1384         if (!bch2_dev_state_allowed(c, ca, new_state, flags))
1385                 return -EINVAL;
1386
1387         if (new_state != BCH_MEMBER_STATE_rw)
1388                 __bch2_dev_read_only(c, ca);
1389
1390         bch_notice(ca, "%s", bch2_member_states[new_state]);
1391
1392         mutex_lock(&c->sb_lock);
1393         mi = bch2_sb_get_members(c->disk_sb.sb);
1394         SET_BCH_MEMBER_STATE(&mi->members[ca->dev_idx], new_state);
1395         bch2_write_super(c);
1396         mutex_unlock(&c->sb_lock);
1397
1398         if (new_state == BCH_MEMBER_STATE_rw)
1399                 __bch2_dev_read_write(c, ca);
1400
1401         rebalance_wakeup(c);
1402
1403         return ret;
1404 }
1405
1406 int bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1407                        enum bch_member_state new_state, int flags)
1408 {
1409         int ret;
1410
1411         down_write(&c->state_lock);
1412         ret = __bch2_dev_set_state(c, ca, new_state, flags);
1413         up_write(&c->state_lock);
1414
1415         return ret;
1416 }
1417
1418 /* Device add/removal: */
1419
1420 static int bch2_dev_remove_alloc(struct bch_fs *c, struct bch_dev *ca)
1421 {
1422         struct bpos start       = POS(ca->dev_idx, 0);
1423         struct bpos end         = POS(ca->dev_idx, U64_MAX);
1424         int ret;
1425
1426         /*
1427          * We clear the LRU and need_discard btrees first so that we don't race
1428          * with bch2_do_invalidates() and bch2_do_discards()
1429          */
1430         ret =   bch2_btree_delete_range(c, BTREE_ID_lru, start, end,
1431                                         BTREE_TRIGGER_NORUN, NULL) ?:
1432                 bch2_btree_delete_range(c, BTREE_ID_need_discard, start, end,
1433                                         BTREE_TRIGGER_NORUN, NULL) ?:
1434                 bch2_btree_delete_range(c, BTREE_ID_freespace, start, end,
1435                                         BTREE_TRIGGER_NORUN, NULL) ?:
1436                 bch2_btree_delete_range(c, BTREE_ID_backpointers, start, end,
1437                                         BTREE_TRIGGER_NORUN, NULL) ?:
1438                 bch2_btree_delete_range(c, BTREE_ID_alloc, start, end,
1439                                         BTREE_TRIGGER_NORUN, NULL);
1440         if (ret)
1441                 bch_err(c, "error %i removing dev alloc info", ret);
1442
1443         return ret;
1444 }
1445
1446 int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
1447 {
1448         struct bch_sb_field_members *mi;
1449         unsigned dev_idx = ca->dev_idx, data;
1450         int ret = -EINVAL;
1451
1452         down_write(&c->state_lock);
1453
1454         /*
1455          * We consume a reference to ca->ref, regardless of whether we succeed
1456          * or fail:
1457          */
1458         percpu_ref_put(&ca->ref);
1459
1460         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1461                 bch_err(ca, "Cannot remove without losing data");
1462                 goto err;
1463         }
1464
1465         __bch2_dev_read_only(c, ca);
1466
1467         ret = bch2_dev_data_drop(c, ca->dev_idx, flags);
1468         if (ret) {
1469                 bch_err(ca, "Remove failed: error %i dropping data", ret);
1470                 goto err;
1471         }
1472
1473         ret = bch2_dev_remove_alloc(c, ca);
1474         if (ret) {
1475                 bch_err(ca, "Remove failed, error deleting alloc info");
1476                 goto err;
1477         }
1478
1479         ret = bch2_journal_flush_device_pins(&c->journal, ca->dev_idx);
1480         if (ret) {
1481                 bch_err(ca, "Remove failed: error %i flushing journal", ret);
1482                 goto err;
1483         }
1484
1485         ret = bch2_journal_flush(&c->journal);
1486         if (ret) {
1487                 bch_err(ca, "Remove failed, journal error");
1488                 goto err;
1489         }
1490
1491         ret = bch2_replicas_gc2(c);
1492         if (ret) {
1493                 bch_err(ca, "Remove failed: error %i from replicas gc", ret);
1494                 goto err;
1495         }
1496
1497         data = bch2_dev_has_data(c, ca);
1498         if (data) {
1499                 struct printbuf data_has = PRINTBUF;
1500
1501                 prt_bitflags(&data_has, bch2_data_types, data);
1502                 bch_err(ca, "Remove failed, still has data (%s)", data_has.buf);
1503                 printbuf_exit(&data_has);
1504                 ret = -EBUSY;
1505                 goto err;
1506         }
1507
1508         __bch2_dev_offline(c, ca);
1509
1510         mutex_lock(&c->sb_lock);
1511         rcu_assign_pointer(c->devs[ca->dev_idx], NULL);
1512         mutex_unlock(&c->sb_lock);
1513
1514         percpu_ref_kill(&ca->ref);
1515         wait_for_completion(&ca->ref_completion);
1516
1517         bch2_dev_free(ca);
1518
1519         /*
1520          * Free this device's slot in the bch_member array - all pointers to
1521          * this device must be gone:
1522          */
1523         mutex_lock(&c->sb_lock);
1524         mi = bch2_sb_get_members(c->disk_sb.sb);
1525         memset(&mi->members[dev_idx].uuid, 0, sizeof(mi->members[dev_idx].uuid));
1526
1527         bch2_write_super(c);
1528
1529         mutex_unlock(&c->sb_lock);
1530         up_write(&c->state_lock);
1531
1532         bch2_dev_usage_journal_reserve(c);
1533         return 0;
1534 err:
1535         if (ca->mi.state == BCH_MEMBER_STATE_rw &&
1536             !percpu_ref_is_zero(&ca->io_ref))
1537                 __bch2_dev_read_write(c, ca);
1538         up_write(&c->state_lock);
1539         return ret;
1540 }
1541
1542 /* Add new device to running filesystem: */
1543 int bch2_dev_add(struct bch_fs *c, const char *path)
1544 {
1545         struct bch_opts opts = bch2_opts_empty();
1546         struct bch_sb_handle sb;
1547         const char *err;
1548         struct bch_dev *ca = NULL;
1549         struct bch_sb_field_members *mi;
1550         struct bch_member dev_mi;
1551         unsigned dev_idx, nr_devices, u64s;
1552         struct printbuf errbuf = PRINTBUF;
1553         int ret;
1554
1555         ret = bch2_read_super(path, &opts, &sb);
1556         if (ret) {
1557                 bch_err(c, "device add error: error reading super: %i", ret);
1558                 goto err;
1559         }
1560
1561         dev_mi = bch2_sb_get_members(sb.sb)->members[sb.sb->dev_idx];
1562
1563         err = bch2_dev_may_add(sb.sb, c);
1564         if (err) {
1565                 bch_err(c, "device add error: %s", err);
1566                 ret = -EINVAL;
1567                 goto err;
1568         }
1569
1570         ca = __bch2_dev_alloc(c, &dev_mi);
1571         if (!ca) {
1572                 bch2_free_super(&sb);
1573                 ret = -ENOMEM;
1574                 goto err;
1575         }
1576
1577         bch2_dev_usage_init(ca);
1578
1579         ret = __bch2_dev_attach_bdev(ca, &sb);
1580         if (ret) {
1581                 bch2_dev_free(ca);
1582                 goto err;
1583         }
1584
1585         ret = bch2_dev_journal_alloc(ca);
1586         if (ret) {
1587                 bch_err(c, "device add error: journal alloc failed");
1588                 goto err;
1589         }
1590
1591         down_write(&c->state_lock);
1592         mutex_lock(&c->sb_lock);
1593
1594         ret = bch2_sb_from_fs(c, ca);
1595         if (ret) {
1596                 bch_err(c, "device add error: new device superblock too small");
1597                 goto err_unlock;
1598         }
1599
1600         mi = bch2_sb_get_members(ca->disk_sb.sb);
1601
1602         if (!bch2_sb_resize_members(&ca->disk_sb,
1603                                 le32_to_cpu(mi->field.u64s) +
1604                                 sizeof(dev_mi) / sizeof(u64))) {
1605                 bch_err(c, "device add error: new device superblock too small");
1606                 ret = -ENOSPC;
1607                 goto err_unlock;
1608         }
1609
1610         if (dynamic_fault("bcachefs:add:no_slot"))
1611                 goto no_slot;
1612
1613         mi = bch2_sb_get_members(c->disk_sb.sb);
1614         for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
1615                 if (!bch2_dev_exists(c->disk_sb.sb, mi, dev_idx))
1616                         goto have_slot;
1617 no_slot:
1618         bch_err(c, "device add error: already have maximum number of devices");
1619         ret = -ENOSPC;
1620         goto err_unlock;
1621
1622 have_slot:
1623         nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
1624         u64s = (sizeof(struct bch_sb_field_members) +
1625                 sizeof(struct bch_member) * nr_devices) / sizeof(u64);
1626
1627         mi = bch2_sb_resize_members(&c->disk_sb, u64s);
1628         if (!mi) {
1629                 bch_err(c, "device add error: no room in superblock for member info");
1630                 ret = -ENOSPC;
1631                 goto err_unlock;
1632         }
1633
1634         /* success: */
1635
1636         mi->members[dev_idx] = dev_mi;
1637         mi->members[dev_idx].last_mount = cpu_to_le64(ktime_get_real_seconds());
1638         c->disk_sb.sb->nr_devices       = nr_devices;
1639
1640         ca->disk_sb.sb->dev_idx = dev_idx;
1641         bch2_dev_attach(c, ca, dev_idx);
1642
1643         bch2_write_super(c);
1644         mutex_unlock(&c->sb_lock);
1645
1646         bch2_dev_usage_journal_reserve(c);
1647
1648         ret = bch2_trans_mark_dev_sb(c, ca);
1649         if (ret) {
1650                 bch_err(c, "device add error: error marking new superblock: %i", ret);
1651                 goto err_late;
1652         }
1653
1654         ret = bch2_fs_freespace_init(c);
1655         if (ret) {
1656                 bch_err(c, "device add error: error initializing free space: %i", ret);
1657                 goto err_late;
1658         }
1659
1660         ca->new_fs_bucket_idx = 0;
1661
1662         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1663                 __bch2_dev_read_write(c, ca);
1664
1665         up_write(&c->state_lock);
1666         return 0;
1667
1668 err_unlock:
1669         mutex_unlock(&c->sb_lock);
1670         up_write(&c->state_lock);
1671 err:
1672         if (ca)
1673                 bch2_dev_free(ca);
1674         bch2_free_super(&sb);
1675         printbuf_exit(&errbuf);
1676         return ret;
1677 err_late:
1678         up_write(&c->state_lock);
1679         ca = NULL;
1680         goto err;
1681 }
1682
1683 /* Hot add existing device to running filesystem: */
1684 int bch2_dev_online(struct bch_fs *c, const char *path)
1685 {
1686         struct bch_opts opts = bch2_opts_empty();
1687         struct bch_sb_handle sb = { NULL };
1688         struct bch_sb_field_members *mi;
1689         struct bch_dev *ca;
1690         unsigned dev_idx;
1691         const char *err;
1692         int ret;
1693
1694         down_write(&c->state_lock);
1695
1696         ret = bch2_read_super(path, &opts, &sb);
1697         if (ret) {
1698                 up_write(&c->state_lock);
1699                 return ret;
1700         }
1701
1702         dev_idx = sb.sb->dev_idx;
1703
1704         err = bch2_dev_in_fs(c->disk_sb.sb, sb.sb);
1705         if (err) {
1706                 bch_err(c, "error bringing %s online: %s", path, err);
1707                 goto err;
1708         }
1709
1710         ret = bch2_dev_attach_bdev(c, &sb);
1711         if (ret)
1712                 goto err;
1713
1714         ca = bch_dev_locked(c, dev_idx);
1715
1716         ret = bch2_trans_mark_dev_sb(c, ca);
1717         if (ret) {
1718                 bch_err(c, "error bringing %s online: error %i from bch2_trans_mark_dev_sb",
1719                         path, ret);
1720                 goto err;
1721         }
1722
1723         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1724                 __bch2_dev_read_write(c, ca);
1725
1726         mutex_lock(&c->sb_lock);
1727         mi = bch2_sb_get_members(c->disk_sb.sb);
1728
1729         mi->members[ca->dev_idx].last_mount =
1730                 cpu_to_le64(ktime_get_real_seconds());
1731
1732         bch2_write_super(c);
1733         mutex_unlock(&c->sb_lock);
1734
1735         up_write(&c->state_lock);
1736         return 0;
1737 err:
1738         up_write(&c->state_lock);
1739         bch2_free_super(&sb);
1740         return -EINVAL;
1741 }
1742
1743 int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
1744 {
1745         down_write(&c->state_lock);
1746
1747         if (!bch2_dev_is_online(ca)) {
1748                 bch_err(ca, "Already offline");
1749                 up_write(&c->state_lock);
1750                 return 0;
1751         }
1752
1753         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1754                 bch_err(ca, "Cannot offline required disk");
1755                 up_write(&c->state_lock);
1756                 return -EINVAL;
1757         }
1758
1759         __bch2_dev_offline(c, ca);
1760
1761         up_write(&c->state_lock);
1762         return 0;
1763 }
1764
1765 int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
1766 {
1767         struct bch_member *mi;
1768         int ret = 0;
1769
1770         down_write(&c->state_lock);
1771
1772         if (nbuckets < ca->mi.nbuckets) {
1773                 bch_err(ca, "Cannot shrink yet");
1774                 ret = -EINVAL;
1775                 goto err;
1776         }
1777
1778         if (bch2_dev_is_online(ca) &&
1779             get_capacity(ca->disk_sb.bdev->bd_disk) <
1780             ca->mi.bucket_size * nbuckets) {
1781                 bch_err(ca, "New size larger than device");
1782                 ret = -EINVAL;
1783                 goto err;
1784         }
1785
1786         ret = bch2_dev_buckets_resize(c, ca, nbuckets);
1787         if (ret) {
1788                 bch_err(ca, "Resize error: %i", ret);
1789                 goto err;
1790         }
1791
1792         ret = bch2_trans_mark_dev_sb(c, ca);
1793         if (ret) {
1794                 goto err;
1795         }
1796
1797         mutex_lock(&c->sb_lock);
1798         mi = &bch2_sb_get_members(c->disk_sb.sb)->members[ca->dev_idx];
1799         mi->nbuckets = cpu_to_le64(nbuckets);
1800
1801         bch2_write_super(c);
1802         mutex_unlock(&c->sb_lock);
1803
1804         bch2_recalc_capacity(c);
1805 err:
1806         up_write(&c->state_lock);
1807         return ret;
1808 }
1809
1810 /* return with ref on ca->ref: */
1811 struct bch_dev *bch2_dev_lookup(struct bch_fs *c, const char *name)
1812 {
1813         struct bch_dev *ca;
1814         unsigned i;
1815
1816         rcu_read_lock();
1817         for_each_member_device_rcu(ca, c, i, NULL)
1818                 if (!strcmp(name, ca->name))
1819                         goto found;
1820         ca = ERR_PTR(-ENOENT);
1821 found:
1822         rcu_read_unlock();
1823
1824         return ca;
1825 }
1826
1827 /* Filesystem open: */
1828
1829 struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
1830                             struct bch_opts opts)
1831 {
1832         struct bch_sb_handle *sb = NULL;
1833         struct bch_fs *c = NULL;
1834         struct bch_sb_field_members *mi;
1835         unsigned i, best_sb = 0;
1836         const char *err;
1837         struct printbuf errbuf = PRINTBUF;
1838         int ret = 0;
1839
1840         if (!try_module_get(THIS_MODULE))
1841                 return ERR_PTR(-ENODEV);
1842
1843         pr_verbose_init(opts, "");
1844
1845         if (!nr_devices) {
1846                 ret = -EINVAL;
1847                 goto err;
1848         }
1849
1850         sb = kcalloc(nr_devices, sizeof(*sb), GFP_KERNEL);
1851         if (!sb) {
1852                 ret = -ENOMEM;
1853                 goto err;
1854         }
1855
1856         for (i = 0; i < nr_devices; i++) {
1857                 ret = bch2_read_super(devices[i], &opts, &sb[i]);
1858                 if (ret)
1859                         goto err;
1860
1861         }
1862
1863         for (i = 1; i < nr_devices; i++)
1864                 if (le64_to_cpu(sb[i].sb->seq) >
1865                     le64_to_cpu(sb[best_sb].sb->seq))
1866                         best_sb = i;
1867
1868         mi = bch2_sb_get_members(sb[best_sb].sb);
1869
1870         i = 0;
1871         while (i < nr_devices) {
1872                 if (i != best_sb &&
1873                     !bch2_dev_exists(sb[best_sb].sb, mi, sb[i].sb->dev_idx)) {
1874                         char buf[BDEVNAME_SIZE];
1875                         pr_info("%s has been removed, skipping",
1876                                 bdevname(sb[i].bdev, buf));
1877                         bch2_free_super(&sb[i]);
1878                         array_remove_item(sb, nr_devices, i);
1879                         continue;
1880                 }
1881
1882                 err = bch2_dev_in_fs(sb[best_sb].sb, sb[i].sb);
1883                 if (err)
1884                         goto err_print;
1885                 i++;
1886         }
1887
1888         c = bch2_fs_alloc(sb[best_sb].sb, opts);
1889         if (IS_ERR(c)) {
1890                 ret = PTR_ERR(c);
1891                 goto err;
1892         }
1893
1894         down_write(&c->state_lock);
1895         for (i = 0; i < nr_devices; i++) {
1896                 ret = bch2_dev_attach_bdev(c, &sb[i]);
1897                 if (ret) {
1898                         up_write(&c->state_lock);
1899                         goto err;
1900                 }
1901         }
1902         up_write(&c->state_lock);
1903
1904         err = "insufficient devices";
1905         if (!bch2_fs_may_start(c))
1906                 goto err_print;
1907
1908         if (!c->opts.nostart) {
1909                 ret = bch2_fs_start(c);
1910                 if (ret)
1911                         goto err;
1912         }
1913 out:
1914         kfree(sb);
1915         printbuf_exit(&errbuf);
1916         module_put(THIS_MODULE);
1917         pr_verbose_init(opts, "ret %i", PTR_ERR_OR_ZERO(c));
1918         return c;
1919 err_print:
1920         pr_err("bch_fs_open err opening %s: %s",
1921                devices[0], err);
1922         ret = -EINVAL;
1923 err:
1924         if (!IS_ERR_OR_NULL(c))
1925                 bch2_fs_stop(c);
1926         if (sb)
1927                 for (i = 0; i < nr_devices; i++)
1928                         bch2_free_super(&sb[i]);
1929         c = ERR_PTR(ret);
1930         goto out;
1931 }
1932
1933 /* Global interfaces/init */
1934
1935 static void bcachefs_exit(void)
1936 {
1937         bch2_debug_exit();
1938         bch2_vfs_exit();
1939         bch2_chardev_exit();
1940         bch2_btree_key_cache_exit();
1941         if (bcachefs_kset)
1942                 kset_unregister(bcachefs_kset);
1943 }
1944
1945 static int __init bcachefs_init(void)
1946 {
1947         bch2_bkey_pack_test();
1948
1949         if (!(bcachefs_kset = kset_create_and_add("bcachefs", NULL, fs_kobj)) ||
1950             bch2_btree_key_cache_init() ||
1951             bch2_chardev_init() ||
1952             bch2_vfs_init() ||
1953             bch2_debug_init())
1954                 goto err;
1955
1956         return 0;
1957 err:
1958         bcachefs_exit();
1959         return -ENOMEM;
1960 }
1961
1962 #define BCH_DEBUG_PARAM(name, description)                      \
1963         bool bch2_##name;                                       \
1964         module_param_named(name, bch2_##name, bool, 0644);      \
1965         MODULE_PARM_DESC(name, description);
1966 BCH_DEBUG_PARAMS()
1967 #undef BCH_DEBUG_PARAM
1968
1969 module_exit(bcachefs_exit);
1970 module_init(bcachefs_init);