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 "btree_write_buffer.h"
  20 #include "buckets_waiting_for_journal.h"
  21 #include "chardev.h"
  22 #include "checksum.h"
  23 #include "clock.h"
  24 #include "compress.h"
  25 #include "debug.h"
  26 #include "disk_groups.h"
  27 #include "ec.h"
  28 #include "errcode.h"
  29 #include "error.h"
  30 #include "fs.h"
  31 #include "fs-io.h"
  32 #include "fsck.h"
  33 #include "inode.h"
  34 #include "io.h"
  35 #include "journal.h"
  36 #include "journal_reclaim.h"
  37 #include "journal_seq_blacklist.h"
  38 #include "move.h"
  39 #include "migrate.h"
  40 #include "movinggc.h"
  41 #include "nocow_locking.h"
  42 #include "quota.h"
  43 #include "rebalance.h"
  44 #include "recovery.h"
  45 #include "replicas.h"
  46 #include "subvolume.h"
  47 #include "super.h"
  48 #include "super-io.h"
  49 #include "sysfs.h"
  50 #include "counters.h"
  51
  52 #include <linux/backing-dev.h>
  53 #include <linux/blkdev.h>
  54 #include <linux/debugfs.h>
  55 #include <linux/device.h>
  56 #include <linux/idr.h>
  57 #include <linux/module.h>
  58 #include <linux/percpu.h>
  59 #include <linux/random.h>
  60 #include <linux/sysfs.h>
  61 #include <crypto/hash.h>
  62
  63 #include <trace/events/bcachefs.h>
  64
  65 MODULE_LICENSE("GPL");
  66 MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
  67
  68 #define KTYPE(type)                                                     \
  69 static const struct attribute_group type ## _group = {                  \
  70         .attrs = type ## _files                                         \
  71 };                                                                      \
  72                                                                         \
  73 static const struct attribute_group *type ## _groups[] = {              \
  74         &type ## _group,                                                \
  75         NULL                                                            \
  76 };                                                                      \
  77                                                                         \
  78 static const struct kobj_type type ## _ktype = {                        \
  79         .release        = type ## _release,                             \
  80         .sysfs_ops      = &type ## _sysfs_ops,                          \
  81         .default_groups = type ## _groups                               \
  82 }
  83
  84 static void bch2_fs_release(struct kobject *);
  85 static void bch2_dev_release(struct kobject *);
  86 static void bch2_fs_counters_release(struct kobject *k)
  87 {
  88 }
  89
  90 static void bch2_fs_internal_release(struct kobject *k)
  91 {
  92 }
  93
  94 static void bch2_fs_opts_dir_release(struct kobject *k)
  95 {
  96 }
  97
  98 static void bch2_fs_time_stats_release(struct kobject *k)
  99 {
 100 }
 101
 102 KTYPE(bch2_fs);
 103 KTYPE(bch2_fs_counters);
 104 KTYPE(bch2_fs_internal);
 105 KTYPE(bch2_fs_opts_dir);
 106 KTYPE(bch2_fs_time_stats);
 107 KTYPE(bch2_dev);
 108
 109 static struct kset *bcachefs_kset;
 110 static LIST_HEAD(bch_fs_list);
 111 static DEFINE_MUTEX(bch_fs_list_lock);
 112
 113 DECLARE_WAIT_QUEUE_HEAD(bch2_read_only_wait);
 114
 115 static void bch2_dev_free(struct bch_dev *);
 116 static int bch2_dev_alloc(struct bch_fs *, unsigned);
 117 static int bch2_dev_sysfs_online(struct bch_fs *, struct bch_dev *);
 118 static void __bch2_dev_read_only(struct bch_fs *, struct bch_dev *);
 119
 120 struct bch_fs *bch2_dev_to_fs(dev_t dev)
 121 {
 122         struct bch_fs *c;
 123         struct bch_dev *ca;
 124         unsigned i;
 125
 126         mutex_lock(&bch_fs_list_lock);
 127         rcu_read_lock();
 128
 129         list_for_each_entry(c, &bch_fs_list, list)
 130                 for_each_member_device_rcu(ca, c, i, NULL)
 131                         if (ca->disk_sb.bdev && ca->disk_sb.bdev->bd_dev == dev) {
 132                                 closure_get(&c->cl);
 133                                 goto found;
 134                         }
 135         c = NULL;
 136 found:
 137         rcu_read_unlock();
 138         mutex_unlock(&bch_fs_list_lock);
 139
 140         return c;
 141 }
 142
 143 static struct bch_fs *__bch2_uuid_to_fs(uuid_le uuid)
 144 {
 145         struct bch_fs *c;
 146
 147         lockdep_assert_held(&bch_fs_list_lock);
 148
 149         list_for_each_entry(c, &bch_fs_list, list)
 150                 if (!memcmp(&c->disk_sb.sb->uuid, &uuid, sizeof(uuid_le)))
 151                         return c;
 152
 153         return NULL;
 154 }
 155
 156 struct bch_fs *bch2_uuid_to_fs(uuid_le uuid)
 157 {
 158         struct bch_fs *c;
 159
 160         mutex_lock(&bch_fs_list_lock);
 161         c = __bch2_uuid_to_fs(uuid);
 162         if (c)
 163                 closure_get(&c->cl);
 164         mutex_unlock(&bch_fs_list_lock);
 165
 166         return c;
 167 }
 168
 169 static void bch2_dev_usage_journal_reserve(struct bch_fs *c)
 170 {
 171         struct bch_dev *ca;
 172         unsigned i, nr = 0, u64s =
 173                 ((sizeof(struct jset_entry_dev_usage) +
 174                   sizeof(struct jset_entry_dev_usage_type) * BCH_DATA_NR)) /
 175                 sizeof(u64);
 176
 177         rcu_read_lock();
 178         for_each_member_device_rcu(ca, c, i, NULL)
 179                 nr++;
 180         rcu_read_unlock();
 181
 182         bch2_journal_entry_res_resize(&c->journal,
 183                         &c->dev_usage_journal_res, u64s * nr);
 184 }
 185
 186 /* Filesystem RO/RW: */
 187
 188 /*
 189  * For startup/shutdown of RW stuff, the dependencies are:
 190  *
 191  * - foreground writes depend on copygc and rebalance (to free up space)
 192  *
 193  * - copygc and rebalance depend on mark and sweep gc (they actually probably
 194  *   don't because they either reserve ahead of time or don't block if
 195  *   allocations fail, but allocations can require mark and sweep gc to run
 196  *   because of generation number wraparound)
 197  *
 198  * - all of the above depends on the allocator threads
 199  *
 200  * - allocator depends on the journal (when it rewrites prios and gens)
 201  */
 202
 203 static void __bch2_fs_read_only(struct bch_fs *c)
 204 {
 205         struct bch_dev *ca;
 206         unsigned i, clean_passes = 0;
 207         u64 seq = 0;
 208
 209         bch2_rebalance_stop(c);
 210         bch2_copygc_stop(c);
 211         bch2_gc_thread_stop(c);
 212
 213         bch_verbose(c, "flushing journal and stopping allocators");
 214
 215         do {
 216                 clean_passes++;
 217
 218                 if (bch2_btree_interior_updates_flush(c) ||
 219                     bch2_journal_flush_all_pins(&c->journal) ||
 220                     bch2_btree_flush_all_writes(c) ||
 221                     seq != atomic64_read(&c->journal.seq)) {
 222                         seq = atomic64_read(&c->journal.seq);
 223                         clean_passes = 0;
 224                 }
 225         } while (clean_passes < 2);
 226
 227         bch_verbose(c, "flushing journal and stopping allocators complete");
 228
 229         if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
 230             !test_bit(BCH_FS_EMERGENCY_RO, &c->flags))
 231                 set_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
 232         bch2_fs_journal_stop(&c->journal);
 233
 234         /*
 235          * After stopping journal:
 236          */
 237         for_each_member_device(ca, c, i)
 238                 bch2_dev_allocator_remove(c, ca);
 239 }
 240
 241 #ifndef BCH_WRITE_REF_DEBUG
 242 static void bch2_writes_disabled(struct percpu_ref *writes)
 243 {
 244         struct bch_fs *c = container_of(writes, struct bch_fs, writes);
 245
 246         set_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
 247         wake_up(&bch2_read_only_wait);
 248 }
 249 #endif
 250
 251 void bch2_fs_read_only(struct bch_fs *c)
 252 {
 253         if (!test_bit(BCH_FS_RW, &c->flags)) {
 254                 bch2_journal_reclaim_stop(&c->journal);
 255                 return;
 256         }
 257
 258         BUG_ON(test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags));
 259
 260         /*
 261          * Block new foreground-end write operations from starting - any new
 262          * writes will return -EROFS:
 263          */
 264         set_bit(BCH_FS_GOING_RO, &c->flags);
 265 #ifndef BCH_WRITE_REF_DEBUG
 266         percpu_ref_kill(&c->writes);
 267 #else
 268         for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++)
 269                 bch2_write_ref_put(c, i);
 270 #endif
 271
 272         /*
 273          * If we're not doing an emergency shutdown, we want to wait on
 274          * outstanding writes to complete so they don't see spurious errors due
 275          * to shutting down the allocator:
 276          *
 277          * If we are doing an emergency shutdown outstanding writes may
 278          * hang until we shutdown the allocator so we don't want to wait
 279          * on outstanding writes before shutting everything down - but
 280          * we do need to wait on them before returning and signalling
 281          * that going RO is complete:
 282          */
 283         wait_event(bch2_read_only_wait,
 284                    test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags) ||
 285                    test_bit(BCH_FS_EMERGENCY_RO, &c->flags));
 286
 287         __bch2_fs_read_only(c);
 288
 289         wait_event(bch2_read_only_wait,
 290                    test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags));
 291
 292         clear_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
 293         clear_bit(BCH_FS_GOING_RO, &c->flags);
 294
 295         if (!bch2_journal_error(&c->journal) &&
 296             !test_bit(BCH_FS_ERROR, &c->flags) &&
 297             !test_bit(BCH_FS_EMERGENCY_RO, &c->flags) &&
 298             test_bit(BCH_FS_STARTED, &c->flags) &&
 299             test_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags) &&
 300             !c->opts.norecovery) {
 301                 bch_verbose(c, "marking filesystem clean");
 302                 bch2_fs_mark_clean(c);
 303         }
 304
 305         clear_bit(BCH_FS_RW, &c->flags);
 306 }
 307
 308 static void bch2_fs_read_only_work(struct work_struct *work)
 309 {
 310         struct bch_fs *c =
 311                 container_of(work, struct bch_fs, read_only_work);
 312
 313         down_write(&c->state_lock);
 314         bch2_fs_read_only(c);
 315         up_write(&c->state_lock);
 316 }
 317
 318 static void bch2_fs_read_only_async(struct bch_fs *c)
 319 {
 320         queue_work(system_long_wq, &c->read_only_work);
 321 }
 322
 323 bool bch2_fs_emergency_read_only(struct bch_fs *c)
 324 {
 325         bool ret = !test_and_set_bit(BCH_FS_EMERGENCY_RO, &c->flags);
 326
 327         bch2_journal_halt(&c->journal);
 328         bch2_fs_read_only_async(c);
 329
 330         wake_up(&bch2_read_only_wait);
 331         return ret;
 332 }
 333
 334 static int bch2_fs_read_write_late(struct bch_fs *c)
 335 {
 336         int ret;
 337
 338         ret = bch2_rebalance_start(c);
 339         if (ret) {
 340                 bch_err(c, "error starting rebalance thread");
 341                 return ret;
 342         }
 343
 344         return 0;
 345 }
 346
 347 static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 348 {
 349         struct bch_dev *ca;
 350         unsigned i;
 351         int ret;
 352
 353         if (test_bit(BCH_FS_INITIAL_GC_UNFIXED, &c->flags)) {
 354                 bch_err(c, "cannot go rw, unfixed btree errors");
 355                 return -EROFS;
 356         }
 357
 358         if (test_bit(BCH_FS_RW, &c->flags))
 359                 return 0;
 360
 361         /*
 362          * nochanges is used for fsck -n mode - we have to allow going rw
 363          * during recovery for that to work:
 364          */
 365         if (c->opts.norecovery ||
 366             (c->opts.nochanges &&
 367              (!early || c->opts.read_only)))
 368                 return -EROFS;
 369
 370         bch_info(c, "going read-write");
 371
 372         ret = bch2_fs_mark_dirty(c);
 373         if (ret)
 374                 goto err;
 375
 376         clear_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
 377
 378         /*
 379          * First journal write must be a flush write: after a clean shutdown we
 380          * don't read the journal, so the first journal write may end up
 381          * overwriting whatever was there previously, and there must always be
 382          * at least one non-flush write in the journal or recovery will fail:
 383          */
 384         set_bit(JOURNAL_NEED_FLUSH_WRITE, &c->journal.flags);
 385
 386         for_each_rw_member(ca, c, i)
 387                 bch2_dev_allocator_add(c, ca);
 388         bch2_recalc_capacity(c);
 389
 390         ret = bch2_gc_thread_start(c);
 391         if (ret) {
 392                 bch_err(c, "error starting gc thread");
 393                 return ret;
 394         }
 395
 396         ret = bch2_copygc_start(c);
 397         if (ret) {
 398                 bch_err(c, "error starting copygc thread");
 399                 return ret;
 400         }
 401
 402         if (!early) {
 403                 ret = bch2_fs_read_write_late(c);
 404                 if (ret)
 405                         goto err;
 406         }
 407
 408 #ifndef BCH_WRITE_REF_DEBUG
 409         percpu_ref_reinit(&c->writes);
 410 #else
 411         for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) {
 412                 BUG_ON(atomic_long_read(&c->writes[i]));
 413                 atomic_long_inc(&c->writes[i]);
 414         }
 415 #endif
 416         set_bit(BCH_FS_RW, &c->flags);
 417         set_bit(BCH_FS_WAS_RW, &c->flags);
 418
 419         bch2_do_discards(c);
 420         bch2_do_invalidates(c);
 421         bch2_do_stripe_deletes(c);
 422         bch2_do_pending_node_rewrites(c);
 423         return 0;
 424 err:
 425         __bch2_fs_read_only(c);
 426         return ret;
 427 }
 428
 429 int bch2_fs_read_write(struct bch_fs *c)
 430 {
 431         return __bch2_fs_read_write(c, false);
 432 }
 433
 434 int bch2_fs_read_write_early(struct bch_fs *c)
 435 {
 436         lockdep_assert_held(&c->state_lock);
 437
 438         return __bch2_fs_read_write(c, true);
 439 }
 440
 441 /* Filesystem startup/shutdown: */
 442
 443 static void __bch2_fs_free(struct bch_fs *c)
 444 {
 445         unsigned i;
 446         int cpu;
 447
 448         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 449                 bch2_time_stats_exit(&c->times[i]);
 450
 451         bch2_free_pending_node_rewrites(c);
 452         bch2_fs_counters_exit(c);
 453         bch2_fs_snapshots_exit(c);
 454         bch2_fs_quota_exit(c);
 455         bch2_fs_fsio_exit(c);
 456         bch2_fs_ec_exit(c);
 457         bch2_fs_encryption_exit(c);
 458         bch2_fs_io_exit(c);
 459         bch2_fs_buckets_waiting_for_journal_exit(c);
 460         bch2_fs_btree_interior_update_exit(c);
 461         bch2_fs_btree_iter_exit(c);
 462         bch2_fs_btree_key_cache_exit(&c->btree_key_cache);
 463         bch2_fs_btree_cache_exit(c);
 464         bch2_fs_replicas_exit(c);
 465         bch2_fs_journal_exit(&c->journal);
 466         bch2_io_clock_exit(&c->io_clock[WRITE]);
 467         bch2_io_clock_exit(&c->io_clock[READ]);
 468         bch2_fs_compress_exit(c);
 469         bch2_journal_keys_free(&c->journal_keys);
 470         bch2_journal_entries_free(c);
 471         bch2_fs_btree_write_buffer_exit(c);
 472         percpu_free_rwsem(&c->mark_lock);
 473         free_percpu(c->online_reserved);
 474
 475         if (c->btree_paths_bufs)
 476                 for_each_possible_cpu(cpu)
 477                         kfree(per_cpu_ptr(c->btree_paths_bufs, cpu)->path);
 478
 479         free_percpu(c->btree_paths_bufs);
 480         free_percpu(c->pcpu);
 481         mempool_exit(&c->large_bkey_pool);
 482         mempool_exit(&c->btree_bounce_pool);
 483         bioset_exit(&c->btree_bio);
 484         mempool_exit(&c->fill_iter);
 485 #ifndef BCH_WRITE_REF_DEBUG
 486         percpu_ref_exit(&c->writes);
 487 #endif
 488         kfree(rcu_dereference_protected(c->disk_groups, 1));
 489         kfree(c->journal_seq_blacklist_table);
 490         kfree(c->unused_inode_hints);
 491
 492         if (c->io_complete_wq)
 493                 destroy_workqueue(c->io_complete_wq);
 494         if (c->copygc_wq)
 495                 destroy_workqueue(c->copygc_wq);
 496         if (c->btree_io_complete_wq)
 497                 destroy_workqueue(c->btree_io_complete_wq);
 498         if (c->btree_update_wq)
 499                 destroy_workqueue(c->btree_update_wq);
 500
 501         bch2_free_super(&c->disk_sb);
 502         kvpfree(c, sizeof(*c));
 503         module_put(THIS_MODULE);
 504 }
 505
 506 static void bch2_fs_release(struct kobject *kobj)
 507 {
 508         struct bch_fs *c = container_of(kobj, struct bch_fs, kobj);
 509
 510         __bch2_fs_free(c);
 511 }
 512
 513 void __bch2_fs_stop(struct bch_fs *c)
 514 {
 515         struct bch_dev *ca;
 516         unsigned i;
 517
 518         bch_verbose(c, "shutting down");
 519
 520         set_bit(BCH_FS_STOPPING, &c->flags);
 521
 522         cancel_work_sync(&c->journal_seq_blacklist_gc_work);
 523
 524         down_write(&c->state_lock);
 525         bch2_fs_read_only(c);
 526         up_write(&c->state_lock);
 527
 528         for_each_member_device(ca, c, i)
 529                 if (ca->kobj.state_in_sysfs &&
 530                     ca->disk_sb.bdev)
 531                         sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
 532
 533         if (c->kobj.state_in_sysfs)
 534                 kobject_del(&c->kobj);
 535
 536         bch2_fs_debug_exit(c);
 537         bch2_fs_chardev_exit(c);
 538
 539         kobject_put(&c->counters_kobj);
 540         kobject_put(&c->time_stats);
 541         kobject_put(&c->opts_dir);
 542         kobject_put(&c->internal);
 543
 544         /* btree prefetch might have kicked off reads in the background: */
 545         bch2_btree_flush_all_reads(c);
 546
 547         for_each_member_device(ca, c, i)
 548                 cancel_work_sync(&ca->io_error_work);
 549
 550         cancel_work_sync(&c->read_only_work);
 551
 552         for (i = 0; i < c->sb.nr_devices; i++)
 553                 if (c->devs[i])
 554                         bch2_free_super(&c->devs[i]->disk_sb);
 555 }
 556
 557 void bch2_fs_free(struct bch_fs *c)
 558 {
 559         unsigned i;
 560
 561         mutex_lock(&bch_fs_list_lock);
 562         list_del(&c->list);
 563         mutex_unlock(&bch_fs_list_lock);
 564
 565         closure_sync(&c->cl);
 566         closure_debug_destroy(&c->cl);
 567
 568         for (i = 0; i < c->sb.nr_devices; i++)
 569                 if (c->devs[i])
 570                         bch2_dev_free(rcu_dereference_protected(c->devs[i], 1));
 571
 572         bch_verbose(c, "shutdown complete");
 573
 574         kobject_put(&c->kobj);
 575 }
 576
 577 void bch2_fs_stop(struct bch_fs *c)
 578 {
 579         __bch2_fs_stop(c);
 580         bch2_fs_free(c);
 581 }
 582
 583 static int bch2_fs_online(struct bch_fs *c)
 584 {
 585         struct bch_dev *ca;
 586         unsigned i;
 587         int ret = 0;
 588
 589         lockdep_assert_held(&bch_fs_list_lock);
 590
 591         if (__bch2_uuid_to_fs(c->sb.uuid)) {
 592                 bch_err(c, "filesystem UUID already open");
 593                 return -EINVAL;
 594         }
 595
 596         ret = bch2_fs_chardev_init(c);
 597         if (ret) {
 598                 bch_err(c, "error creating character device");
 599                 return ret;
 600         }
 601
 602         bch2_fs_debug_init(c);
 603
 604         ret = kobject_add(&c->kobj, NULL, "%pU", c->sb.user_uuid.b) ?:
 605             kobject_add(&c->internal, &c->kobj, "internal") ?:
 606             kobject_add(&c->opts_dir, &c->kobj, "options") ?:
 607             kobject_add(&c->time_stats, &c->kobj, "time_stats") ?:
 608             kobject_add(&c->counters_kobj, &c->kobj, "counters") ?:
 609             bch2_opts_create_sysfs_files(&c->opts_dir);
 610         if (ret) {
 611                 bch_err(c, "error creating sysfs objects");
 612                 return ret;
 613         }
 614
 615         down_write(&c->state_lock);
 616
 617         for_each_member_device(ca, c, i) {
 618                 ret = bch2_dev_sysfs_online(c, ca);
 619                 if (ret) {
 620                         bch_err(c, "error creating sysfs objects");
 621                         percpu_ref_put(&ca->ref);
 622                         goto err;
 623                 }
 624         }
 625
 626         BUG_ON(!list_empty(&c->list));
 627         list_add(&c->list, &bch_fs_list);
 628 err:
 629         up_write(&c->state_lock);
 630         return ret;
 631 }
 632
 633 static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 634 {
 635         struct bch_sb_field_members *mi;
 636         struct bch_fs *c;
 637         struct printbuf name = PRINTBUF;
 638         unsigned i, iter_size;
 639         int ret = 0;
 640
 641         pr_verbose_init(opts, "");
 642
 643         c = kvpmalloc(sizeof(struct bch_fs), GFP_KERNEL|__GFP_ZERO);
 644         if (!c) {
 645                 c = ERR_PTR(-ENOMEM);
 646                 goto out;
 647         }
 648
 649         __module_get(THIS_MODULE);
 650
 651         closure_init(&c->cl, NULL);
 652
 653         c->kobj.kset = bcachefs_kset;
 654         kobject_init(&c->kobj, &bch2_fs_ktype);
 655         kobject_init(&c->internal, &bch2_fs_internal_ktype);
 656         kobject_init(&c->opts_dir, &bch2_fs_opts_dir_ktype);
 657         kobject_init(&c->time_stats, &bch2_fs_time_stats_ktype);
 658         kobject_init(&c->counters_kobj, &bch2_fs_counters_ktype);
 659
 660         c->minor                = -1;
 661         c->disk_sb.fs_sb        = true;
 662
 663         init_rwsem(&c->state_lock);
 664         mutex_init(&c->sb_lock);
 665         mutex_init(&c->replicas_gc_lock);
 666         mutex_init(&c->btree_root_lock);
 667         INIT_WORK(&c->read_only_work, bch2_fs_read_only_work);
 668
 669         init_rwsem(&c->gc_lock);
 670         mutex_init(&c->gc_gens_lock);
 671
 672         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 673                 bch2_time_stats_init(&c->times[i]);
 674
 675         bch2_fs_copygc_init(c);
 676         bch2_fs_btree_key_cache_init_early(&c->btree_key_cache);
 677         bch2_fs_allocator_background_init(c);
 678         bch2_fs_allocator_foreground_init(c);
 679         bch2_fs_rebalance_init(c);
 680         bch2_fs_quota_init(c);
 681         bch2_fs_ec_init_early(c);
 682
 683         INIT_LIST_HEAD(&c->list);
 684
 685         mutex_init(&c->usage_scratch_lock);
 686
 687         mutex_init(&c->bio_bounce_pages_lock);
 688         mutex_init(&c->snapshot_table_lock);
 689
 690         spin_lock_init(&c->btree_write_error_lock);
 691
 692         INIT_WORK(&c->journal_seq_blacklist_gc_work,
 693                   bch2_blacklist_entries_gc);
 694
 695         INIT_LIST_HEAD(&c->journal_iters);
 696
 697         INIT_LIST_HEAD(&c->fsck_errors);
 698         mutex_init(&c->fsck_error_lock);
 699
 700         INIT_LIST_HEAD(&c->ec_stripe_head_list);
 701         mutex_init(&c->ec_stripe_head_lock);
 702
 703         INIT_LIST_HEAD(&c->ec_stripe_new_list);
 704         mutex_init(&c->ec_stripe_new_lock);
 705
 706         INIT_LIST_HEAD(&c->data_progress_list);
 707         mutex_init(&c->data_progress_lock);
 708
 709         mutex_init(&c->ec_stripes_heap_lock);
 710
 711         seqcount_init(&c->gc_pos_lock);
 712
 713         seqcount_init(&c->usage_lock);
 714
 715         sema_init(&c->io_in_flight, 128);
 716
 717         c->copy_gc_enabled              = 1;
 718         c->rebalance.enabled            = 1;
 719         c->promote_whole_extents        = true;
 720
 721         c->journal.flush_write_time     = &c->times[BCH_TIME_journal_flush_write];
 722         c->journal.noflush_write_time   = &c->times[BCH_TIME_journal_noflush_write];
 723         c->journal.blocked_time         = &c->times[BCH_TIME_blocked_journal];
 724         c->journal.flush_seq_time       = &c->times[BCH_TIME_journal_flush_seq];
 725
 726         bch2_fs_btree_cache_init_early(&c->btree_cache);
 727
 728         mutex_init(&c->sectors_available_lock);
 729
 730         ret = percpu_init_rwsem(&c->mark_lock);
 731         if (ret)
 732                 goto err;
 733
 734         mutex_lock(&c->sb_lock);
 735         ret = bch2_sb_to_fs(c, sb);
 736         mutex_unlock(&c->sb_lock);
 737
 738         if (ret)
 739                 goto err;
 740
 741         pr_uuid(&name, c->sb.user_uuid.b);
 742         strscpy(c->name, name.buf, sizeof(c->name));
 743         printbuf_exit(&name);
 744
 745         ret = name.allocation_failure ? -ENOMEM : 0;
 746         if (ret)
 747                 goto err;
 748
 749         /* Compat: */
 750         if (sb->version <= bcachefs_metadata_version_inode_v2 &&
 751             !BCH_SB_JOURNAL_FLUSH_DELAY(sb))
 752                 SET_BCH_SB_JOURNAL_FLUSH_DELAY(sb, 1000);
 753
 754         if (sb->version <= bcachefs_metadata_version_inode_v2 &&
 755             !BCH_SB_JOURNAL_RECLAIM_DELAY(sb))
 756                 SET_BCH_SB_JOURNAL_RECLAIM_DELAY(sb, 100);
 757
 758         c->opts = bch2_opts_default;
 759         ret = bch2_opts_from_sb(&c->opts, sb);
 760         if (ret)
 761                 goto err;
 762
 763         bch2_opts_apply(&c->opts, opts);
 764
 765         c->btree_key_cache_btrees |= 1U << BTREE_ID_alloc;
 766         if (c->opts.inodes_use_key_cache)
 767                 c->btree_key_cache_btrees |= 1U << BTREE_ID_inodes;
 768
 769         c->block_bits           = ilog2(block_sectors(c));
 770         c->btree_foreground_merge_threshold = BTREE_FOREGROUND_MERGE_THRESHOLD(c);
 771
 772         if (bch2_fs_init_fault("fs_alloc")) {
 773                 bch_err(c, "fs_alloc fault injected");
 774                 ret = -EFAULT;
 775                 goto err;
 776         }
 777
 778         iter_size = sizeof(struct sort_iter) +
 779                 (btree_blocks(c) + 1) * 2 *
 780                 sizeof(struct sort_iter_set);
 781
 782         c->inode_shard_bits = ilog2(roundup_pow_of_two(num_possible_cpus()));
 783
 784         if (!(c->btree_update_wq = alloc_workqueue("bcachefs",
 785                                 WQ_FREEZABLE|WQ_UNBOUND|WQ_MEM_RECLAIM, 512)) ||
 786             !(c->btree_io_complete_wq = alloc_workqueue("bcachefs_btree_io",
 787                                 WQ_FREEZABLE|WQ_MEM_RECLAIM, 1)) ||
 788             !(c->copygc_wq = alloc_workqueue("bcachefs_copygc",
 789                                 WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
 790             !(c->io_complete_wq = alloc_workqueue("bcachefs_io",
 791                                 WQ_FREEZABLE|WQ_HIGHPRI|WQ_MEM_RECLAIM, 1)) ||
 792 #ifndef BCH_WRITE_REF_DEBUG
 793             percpu_ref_init(&c->writes, bch2_writes_disabled,
 794                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
 795 #endif
 796             mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
 797             bioset_init(&c->btree_bio, 1,
 798                         max(offsetof(struct btree_read_bio, bio),
 799                             offsetof(struct btree_write_bio, wbio.bio)),
 800                         BIOSET_NEED_BVECS) ||
 801             !(c->pcpu = alloc_percpu(struct bch_fs_pcpu)) ||
 802             !(c->online_reserved = alloc_percpu(u64)) ||
 803             !(c->btree_paths_bufs = alloc_percpu(struct btree_path_buf)) ||
 804             mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
 805                                         btree_bytes(c)) ||
 806             mempool_init_kmalloc_pool(&c->large_bkey_pool, 1, 2048) ||
 807             !(c->unused_inode_hints = kcalloc(1U << c->inode_shard_bits,
 808                                               sizeof(u64), GFP_KERNEL))) {
 809                 ret = -ENOMEM;
 810                 goto err;
 811         }
 812
 813         ret = bch2_fs_counters_init(c) ?:
 814             bch2_io_clock_init(&c->io_clock[READ]) ?:
 815             bch2_io_clock_init(&c->io_clock[WRITE]) ?:
 816             bch2_fs_journal_init(&c->journal) ?:
 817             bch2_fs_replicas_init(c) ?:
 818             bch2_fs_btree_cache_init(c) ?:
 819             bch2_fs_btree_key_cache_init(&c->btree_key_cache) ?:
 820             bch2_fs_btree_iter_init(c) ?:
 821             bch2_fs_btree_interior_update_init(c) ?:
 822             bch2_fs_buckets_waiting_for_journal_init(c) ?:
 823             bch2_fs_btree_write_buffer_init(c) ?:
 824             bch2_fs_subvolumes_init(c) ?:
 825             bch2_fs_io_init(c) ?:
 826             bch2_fs_nocow_locking_init(c) ?:
 827             bch2_fs_encryption_init(c) ?:
 828             bch2_fs_compress_init(c) ?:
 829             bch2_fs_ec_init(c) ?:
 830             bch2_fs_fsio_init(c);
 831         if (ret)
 832                 goto err;
 833
 834         mi = bch2_sb_get_members(c->disk_sb.sb);
 835         for (i = 0; i < c->sb.nr_devices; i++)
 836                 if (bch2_dev_exists(c->disk_sb.sb, mi, i) &&
 837                     bch2_dev_alloc(c, i)) {
 838                         ret = -EEXIST;
 839                         goto err;
 840                 }
 841
 842         bch2_journal_entry_res_resize(&c->journal,
 843                         &c->btree_root_journal_res,
 844                         BTREE_ID_NR * (JSET_KEYS_U64s + BKEY_BTREE_PTR_U64s_MAX));
 845         bch2_dev_usage_journal_reserve(c);
 846         bch2_journal_entry_res_resize(&c->journal,
 847                         &c->clock_journal_res,
 848                         (sizeof(struct jset_entry_clock) / sizeof(u64)) * 2);
 849
 850         mutex_lock(&bch_fs_list_lock);
 851         ret = bch2_fs_online(c);
 852         mutex_unlock(&bch_fs_list_lock);
 853
 854         if (ret)
 855                 goto err;
 856 out:
 857         pr_verbose_init(opts, "ret %i", PTR_ERR_OR_ZERO(c));
 858         return c;
 859 err:
 860         bch2_fs_free(c);
 861         c = ERR_PTR(ret);
 862         goto out;
 863 }
 864
 865 noinline_for_stack
 866 static void print_mount_opts(struct bch_fs *c)
 867 {
 868         enum bch_opt_id i;
 869         struct printbuf p = PRINTBUF;
 870         bool first = true;
 871
 872         prt_printf(&p, "mounted version=%s", bch2_metadata_versions[c->sb.version]);
 873
 874         if (c->opts.read_only) {
 875                 prt_str(&p, " opts=");
 876                 first = false;
 877                 prt_printf(&p, "ro");
 878         }
 879
 880         for (i = 0; i < bch2_opts_nr; i++) {
 881                 const struct bch_option *opt = &bch2_opt_table[i];
 882                 u64 v = bch2_opt_get_by_id(&c->opts, i);
 883
 884                 if (!(opt->flags & OPT_MOUNT))
 885                         continue;
 886
 887                 if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
 888                         continue;
 889
 890                 prt_str(&p, first ? " opts=" : ",");
 891                 first = false;
 892                 bch2_opt_to_text(&p, c, c->disk_sb.sb, opt, v, OPT_SHOW_MOUNT_STYLE);
 893         }
 894
 895         bch_info(c, "%s", p.buf);
 896         printbuf_exit(&p);
 897 }
 898
 899 int bch2_fs_start(struct bch_fs *c)
 900 {
 901         struct bch_sb_field_members *mi;
 902         struct bch_dev *ca;
 903         time64_t now = ktime_get_real_seconds();
 904         unsigned i;
 905         int ret;
 906
 907         down_write(&c->state_lock);
 908
 909         BUG_ON(test_bit(BCH_FS_STARTED, &c->flags));
 910
 911         mutex_lock(&c->sb_lock);
 912
 913         for_each_online_member(ca, c, i)
 914                 bch2_sb_from_fs(c, ca);
 915
 916         mi = bch2_sb_get_members(c->disk_sb.sb);
 917         for_each_online_member(ca, c, i)
 918                 mi->members[ca->dev_idx].last_mount = cpu_to_le64(now);
 919
 920         mutex_unlock(&c->sb_lock);
 921
 922         for_each_rw_member(ca, c, i)
 923                 bch2_dev_allocator_add(c, ca);
 924         bch2_recalc_capacity(c);
 925
 926         for (i = 0; i < BCH_TRANSACTIONS_NR; i++) {
 927                 mutex_lock(&c->btree_transaction_stats[i].lock);
 928                 bch2_time_stats_init(&c->btree_transaction_stats[i].lock_hold_times);
 929                 mutex_unlock(&c->btree_transaction_stats[i].lock);
 930         }
 931
 932         ret = BCH_SB_INITIALIZED(c->disk_sb.sb)
 933                 ? bch2_fs_recovery(c)
 934                 : bch2_fs_initialize(c);
 935         if (ret)
 936                 goto err;
 937
 938         ret = bch2_opts_check_may_set(c);
 939         if (ret)
 940                 goto err;
 941
 942         if (bch2_fs_init_fault("fs_start")) {
 943                 bch_err(c, "fs_start fault injected");
 944                 ret = -EINVAL;
 945                 goto err;
 946         }
 947
 948         set_bit(BCH_FS_STARTED, &c->flags);
 949
 950         if (c->opts.read_only || c->opts.nochanges) {
 951                 bch2_fs_read_only(c);
 952         } else {
 953                 ret = !test_bit(BCH_FS_RW, &c->flags)
 954                         ? bch2_fs_read_write(c)
 955                         : bch2_fs_read_write_late(c);
 956                 if (ret)
 957                         goto err;
 958         }
 959
 960         print_mount_opts(c);
 961         ret = 0;
 962 out:
 963         up_write(&c->state_lock);
 964         return ret;
 965 err:
 966         bch_err(c, "error starting filesystem: %s", bch2_err_str(ret));
 967         goto out;
 968 }
 969
 970 static int bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
 971 {
 972         struct bch_sb_field_members *sb_mi;
 973
 974         sb_mi = bch2_sb_get_members(sb);
 975         if (!sb_mi)
 976                 return -BCH_ERR_member_info_missing;
 977
 978         if (le16_to_cpu(sb->block_size) != block_sectors(c))
 979                 return -BCH_ERR_mismatched_block_size;
 980
 981         if (le16_to_cpu(sb_mi->members[sb->dev_idx].bucket_size) <
 982             BCH_SB_BTREE_NODE_SIZE(c->disk_sb.sb))
 983                 return -BCH_ERR_bucket_size_too_small;
 984
 985         return 0;
 986 }
 987
 988 static int bch2_dev_in_fs(struct bch_sb *fs, struct bch_sb *sb)
 989 {
 990         struct bch_sb *newest =
 991                 le64_to_cpu(fs->seq) > le64_to_cpu(sb->seq) ? fs : sb;
 992         struct bch_sb_field_members *mi = bch2_sb_get_members(newest);
 993
 994         if (uuid_le_cmp(fs->uuid, sb->uuid))
 995                 return -BCH_ERR_device_not_a_member_of_filesystem;
 996
 997         if (!bch2_dev_exists(newest, mi, sb->dev_idx))
 998                 return -BCH_ERR_device_has_been_removed;
 999
1000         if (fs->block_size != sb->block_size)
1001                 return -BCH_ERR_mismatched_block_size;
1002
1003         return 0;
1004 }
1005
1006 /* Device startup/shutdown: */
1007
1008 static void bch2_dev_release(struct kobject *kobj)
1009 {
1010         struct bch_dev *ca = container_of(kobj, struct bch_dev, kobj);
1011
1012         kfree(ca);
1013 }
1014
1015 static void bch2_dev_free(struct bch_dev *ca)
1016 {
1017         cancel_work_sync(&ca->io_error_work);
1018
1019         if (ca->kobj.state_in_sysfs &&
1020             ca->disk_sb.bdev)
1021                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1022
1023         if (ca->kobj.state_in_sysfs)
1024                 kobject_del(&ca->kobj);
1025
1026         bch2_free_super(&ca->disk_sb);
1027         bch2_dev_journal_exit(ca);
1028
1029         free_percpu(ca->io_done);
1030         bioset_exit(&ca->replica_set);
1031         bch2_dev_buckets_free(ca);
1032         free_page((unsigned long) ca->sb_read_scratch);
1033
1034         bch2_time_stats_exit(&ca->io_latency[WRITE]);
1035         bch2_time_stats_exit(&ca->io_latency[READ]);
1036
1037         percpu_ref_exit(&ca->io_ref);
1038         percpu_ref_exit(&ca->ref);
1039         kobject_put(&ca->kobj);
1040 }
1041
1042 static void __bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca)
1043 {
1044
1045         lockdep_assert_held(&c->state_lock);
1046
1047         if (percpu_ref_is_zero(&ca->io_ref))
1048                 return;
1049
1050         __bch2_dev_read_only(c, ca);
1051
1052         reinit_completion(&ca->io_ref_completion);
1053         percpu_ref_kill(&ca->io_ref);
1054         wait_for_completion(&ca->io_ref_completion);
1055
1056         if (ca->kobj.state_in_sysfs) {
1057                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1058                 sysfs_remove_link(&ca->kobj, "block");
1059         }
1060
1061         bch2_free_super(&ca->disk_sb);
1062         bch2_dev_journal_exit(ca);
1063 }
1064
1065 static void bch2_dev_ref_complete(struct percpu_ref *ref)
1066 {
1067         struct bch_dev *ca = container_of(ref, struct bch_dev, ref);
1068
1069         complete(&ca->ref_completion);
1070 }
1071
1072 static void bch2_dev_io_ref_complete(struct percpu_ref *ref)
1073 {
1074         struct bch_dev *ca = container_of(ref, struct bch_dev, io_ref);
1075
1076         complete(&ca->io_ref_completion);
1077 }
1078
1079 static int bch2_dev_sysfs_online(struct bch_fs *c, struct bch_dev *ca)
1080 {
1081         int ret;
1082
1083         if (!c->kobj.state_in_sysfs)
1084                 return 0;
1085
1086         if (!ca->kobj.state_in_sysfs) {
1087                 ret = kobject_add(&ca->kobj, &c->kobj,
1088                                   "dev-%u", ca->dev_idx);
1089                 if (ret)
1090                         return ret;
1091         }
1092
1093         if (ca->disk_sb.bdev) {
1094                 struct kobject *block = bdev_kobj(ca->disk_sb.bdev);
1095
1096                 ret = sysfs_create_link(block, &ca->kobj, "bcachefs");
1097                 if (ret)
1098                         return ret;
1099
1100                 ret = sysfs_create_link(&ca->kobj, block, "block");
1101                 if (ret)
1102                         return ret;
1103         }
1104
1105         return 0;
1106 }
1107
1108 static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
1109                                         struct bch_member *member)
1110 {
1111         struct bch_dev *ca;
1112
1113         ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1114         if (!ca)
1115                 return NULL;
1116
1117         kobject_init(&ca->kobj, &bch2_dev_ktype);
1118         init_completion(&ca->ref_completion);
1119         init_completion(&ca->io_ref_completion);
1120
1121         init_rwsem(&ca->bucket_lock);
1122
1123         INIT_WORK(&ca->io_error_work, bch2_io_error_work);
1124
1125         bch2_time_stats_init(&ca->io_latency[READ]);
1126         bch2_time_stats_init(&ca->io_latency[WRITE]);
1127
1128         ca->mi = bch2_mi_to_cpu(member);
1129         ca->uuid = member->uuid;
1130
1131         ca->nr_btree_reserve = DIV_ROUND_UP(BTREE_NODE_RESERVE,
1132                              ca->mi.bucket_size / btree_sectors(c));
1133
1134         if (percpu_ref_init(&ca->ref, bch2_dev_ref_complete,
1135                             0, GFP_KERNEL) ||
1136             percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
1137                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
1138             !(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
1139             bch2_dev_buckets_alloc(c, ca) ||
1140             bioset_init(&ca->replica_set, 4,
1141                         offsetof(struct bch_write_bio, bio), 0) ||
1142             !(ca->io_done       = alloc_percpu(*ca->io_done)))
1143                 goto err;
1144
1145         return ca;
1146 err:
1147         bch2_dev_free(ca);
1148         return NULL;
1149 }
1150
1151 static void bch2_dev_attach(struct bch_fs *c, struct bch_dev *ca,
1152                             unsigned dev_idx)
1153 {
1154         ca->dev_idx = dev_idx;
1155         __set_bit(ca->dev_idx, ca->self.d);
1156         scnprintf(ca->name, sizeof(ca->name), "dev-%u", dev_idx);
1157
1158         ca->fs = c;
1159         rcu_assign_pointer(c->devs[ca->dev_idx], ca);
1160
1161         if (bch2_dev_sysfs_online(c, ca))
1162                 pr_warn("error creating sysfs objects");
1163 }
1164
1165 static int bch2_dev_alloc(struct bch_fs *c, unsigned dev_idx)
1166 {
1167         struct bch_member *member =
1168                 bch2_sb_get_members(c->disk_sb.sb)->members + dev_idx;
1169         struct bch_dev *ca = NULL;
1170         int ret = 0;
1171
1172         pr_verbose_init(c->opts, "");
1173
1174         if (bch2_fs_init_fault("dev_alloc"))
1175                 goto err;
1176
1177         ca = __bch2_dev_alloc(c, member);
1178         if (!ca)
1179                 goto err;
1180
1181         ca->fs = c;
1182
1183         bch2_dev_attach(c, ca, dev_idx);
1184 out:
1185         pr_verbose_init(c->opts, "ret %i", ret);
1186         return ret;
1187 err:
1188         if (ca)
1189                 bch2_dev_free(ca);
1190         ret = -ENOMEM;
1191         goto out;
1192 }
1193
1194 static int __bch2_dev_attach_bdev(struct bch_dev *ca, struct bch_sb_handle *sb)
1195 {
1196         unsigned ret;
1197
1198         if (bch2_dev_is_online(ca)) {
1199                 bch_err(ca, "already have device online in slot %u",
1200                         sb->sb->dev_idx);
1201                 return -BCH_ERR_device_already_online;
1202         }
1203
1204         if (get_capacity(sb->bdev->bd_disk) <
1205             ca->mi.bucket_size * ca->mi.nbuckets) {
1206                 bch_err(ca, "cannot online: device too small");
1207                 return -BCH_ERR_device_size_too_small;
1208         }
1209
1210         BUG_ON(!percpu_ref_is_zero(&ca->io_ref));
1211
1212         ret = bch2_dev_journal_init(ca, sb->sb);
1213         if (ret)
1214                 return ret;
1215
1216         /* Commit: */
1217         ca->disk_sb = *sb;
1218         if (sb->mode & FMODE_EXCL)
1219                 ca->disk_sb.bdev->bd_holder = ca;
1220         memset(sb, 0, sizeof(*sb));
1221
1222         ca->dev = ca->disk_sb.bdev->bd_dev;
1223
1224         percpu_ref_reinit(&ca->io_ref);
1225
1226         return 0;
1227 }
1228
1229 static int bch2_dev_attach_bdev(struct bch_fs *c, struct bch_sb_handle *sb)
1230 {
1231         struct bch_dev *ca;
1232         int ret;
1233
1234         lockdep_assert_held(&c->state_lock);
1235
1236         if (le64_to_cpu(sb->sb->seq) >
1237             le64_to_cpu(c->disk_sb.sb->seq))
1238                 bch2_sb_to_fs(c, sb->sb);
1239
1240         BUG_ON(sb->sb->dev_idx >= c->sb.nr_devices ||
1241                !c->devs[sb->sb->dev_idx]);
1242
1243         ca = bch_dev_locked(c, sb->sb->dev_idx);
1244
1245         ret = __bch2_dev_attach_bdev(ca, sb);
1246         if (ret)
1247                 return ret;
1248
1249         bch2_dev_sysfs_online(c, ca);
1250
1251         if (c->sb.nr_devices == 1)
1252                 snprintf(c->name, sizeof(c->name), "%pg", ca->disk_sb.bdev);
1253         snprintf(ca->name, sizeof(ca->name), "%pg", ca->disk_sb.bdev);
1254
1255         rebalance_wakeup(c);
1256         return 0;
1257 }
1258
1259 /* Device management: */
1260
1261 /*
1262  * Note: this function is also used by the error paths - when a particular
1263  * device sees an error, we call it to determine whether we can just set the
1264  * device RO, or - if this function returns false - we'll set the whole
1265  * filesystem RO:
1266  *
1267  * XXX: maybe we should be more explicit about whether we're changing state
1268  * because we got an error or what have you?
1269  */
1270 bool bch2_dev_state_allowed(struct bch_fs *c, struct bch_dev *ca,
1271                             enum bch_member_state new_state, int flags)
1272 {
1273         struct bch_devs_mask new_online_devs;
1274         struct bch_dev *ca2;
1275         int i, nr_rw = 0, required;
1276
1277         lockdep_assert_held(&c->state_lock);
1278
1279         switch (new_state) {
1280         case BCH_MEMBER_STATE_rw:
1281                 return true;
1282         case BCH_MEMBER_STATE_ro:
1283                 if (ca->mi.state != BCH_MEMBER_STATE_rw)
1284                         return true;
1285
1286                 /* do we have enough devices to write to?  */
1287                 for_each_member_device(ca2, c, i)
1288                         if (ca2 != ca)
1289                                 nr_rw += ca2->mi.state == BCH_MEMBER_STATE_rw;
1290
1291                 required = max(!(flags & BCH_FORCE_IF_METADATA_DEGRADED)
1292                                ? c->opts.metadata_replicas
1293                                : c->opts.metadata_replicas_required,
1294                                !(flags & BCH_FORCE_IF_DATA_DEGRADED)
1295                                ? c->opts.data_replicas
1296                                : c->opts.data_replicas_required);
1297
1298                 return nr_rw >= required;
1299         case BCH_MEMBER_STATE_failed:
1300         case BCH_MEMBER_STATE_spare:
1301                 if (ca->mi.state != BCH_MEMBER_STATE_rw &&
1302                     ca->mi.state != BCH_MEMBER_STATE_ro)
1303                         return true;
1304
1305                 /* do we have enough devices to read from?  */
1306                 new_online_devs = bch2_online_devs(c);
1307                 __clear_bit(ca->dev_idx, new_online_devs.d);
1308
1309                 return bch2_have_enough_devs(c, new_online_devs, flags, false);
1310         default:
1311                 BUG();
1312         }
1313 }
1314
1315 static bool bch2_fs_may_start(struct bch_fs *c)
1316 {
1317         struct bch_sb_field_members *mi;
1318         struct bch_dev *ca;
1319         unsigned i, flags = 0;
1320
1321         if (c->opts.very_degraded)
1322                 flags |= BCH_FORCE_IF_DEGRADED|BCH_FORCE_IF_LOST;
1323
1324         if (c->opts.degraded)
1325                 flags |= BCH_FORCE_IF_DEGRADED;
1326
1327         if (!c->opts.degraded &&
1328             !c->opts.very_degraded) {
1329                 mutex_lock(&c->sb_lock);
1330                 mi = bch2_sb_get_members(c->disk_sb.sb);
1331
1332                 for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
1333                         if (!bch2_dev_exists(c->disk_sb.sb, mi, i))
1334                                 continue;
1335
1336                         ca = bch_dev_locked(c, i);
1337
1338                         if (!bch2_dev_is_online(ca) &&
1339                             (ca->mi.state == BCH_MEMBER_STATE_rw ||
1340                              ca->mi.state == BCH_MEMBER_STATE_ro)) {
1341                                 mutex_unlock(&c->sb_lock);
1342                                 return false;
1343                         }
1344                 }
1345                 mutex_unlock(&c->sb_lock);
1346         }
1347
1348         return bch2_have_enough_devs(c, bch2_online_devs(c), flags, true);
1349 }
1350
1351 static void __bch2_dev_read_only(struct bch_fs *c, struct bch_dev *ca)
1352 {
1353         /*
1354          * The allocator thread itself allocates btree nodes, so stop it first:
1355          */
1356         bch2_dev_allocator_remove(c, ca);
1357         bch2_dev_journal_stop(&c->journal, ca);
1358 }
1359
1360 static void __bch2_dev_read_write(struct bch_fs *c, struct bch_dev *ca)
1361 {
1362         lockdep_assert_held(&c->state_lock);
1363
1364         BUG_ON(ca->mi.state != BCH_MEMBER_STATE_rw);
1365
1366         bch2_dev_allocator_add(c, ca);
1367         bch2_recalc_capacity(c);
1368 }
1369
1370 int __bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1371                          enum bch_member_state new_state, int flags)
1372 {
1373         struct bch_sb_field_members *mi;
1374         int ret = 0;
1375
1376         if (ca->mi.state == new_state)
1377                 return 0;
1378
1379         if (!bch2_dev_state_allowed(c, ca, new_state, flags))
1380                 return -BCH_ERR_device_state_not_allowed;
1381
1382         if (new_state != BCH_MEMBER_STATE_rw)
1383                 __bch2_dev_read_only(c, ca);
1384
1385         bch_notice(ca, "%s", bch2_member_states[new_state]);
1386
1387         mutex_lock(&c->sb_lock);
1388         mi = bch2_sb_get_members(c->disk_sb.sb);
1389         SET_BCH_MEMBER_STATE(&mi->members[ca->dev_idx], new_state);
1390         bch2_write_super(c);
1391         mutex_unlock(&c->sb_lock);
1392
1393         if (new_state == BCH_MEMBER_STATE_rw)
1394                 __bch2_dev_read_write(c, ca);
1395
1396         rebalance_wakeup(c);
1397
1398         return ret;
1399 }
1400
1401 int bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1402                        enum bch_member_state new_state, int flags)
1403 {
1404         int ret;
1405
1406         down_write(&c->state_lock);
1407         ret = __bch2_dev_set_state(c, ca, new_state, flags);
1408         up_write(&c->state_lock);
1409
1410         return ret;
1411 }
1412
1413 /* Device add/removal: */
1414
1415 static int bch2_dev_remove_alloc(struct bch_fs *c, struct bch_dev *ca)
1416 {
1417         struct bpos start       = POS(ca->dev_idx, 0);
1418         struct bpos end         = POS(ca->dev_idx, U64_MAX);
1419         int ret;
1420
1421         /*
1422          * We clear the LRU and need_discard btrees first so that we don't race
1423          * with bch2_do_invalidates() and bch2_do_discards()
1424          */
1425         ret =   bch2_btree_delete_range(c, BTREE_ID_lru, start, end,
1426                                         BTREE_TRIGGER_NORUN, NULL) ?:
1427                 bch2_btree_delete_range(c, BTREE_ID_need_discard, start, end,
1428                                         BTREE_TRIGGER_NORUN, NULL) ?:
1429                 bch2_btree_delete_range(c, BTREE_ID_freespace, start, end,
1430                                         BTREE_TRIGGER_NORUN, NULL) ?:
1431                 bch2_btree_delete_range(c, BTREE_ID_backpointers, start, end,
1432                                         BTREE_TRIGGER_NORUN, NULL) ?:
1433                 bch2_btree_delete_range(c, BTREE_ID_alloc, start, end,
1434                                         BTREE_TRIGGER_NORUN, NULL);
1435         if (ret)
1436                 bch_err(c, "error removing dev alloc info: %s", bch2_err_str(ret));
1437
1438         return ret;
1439 }
1440
1441 int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
1442 {
1443         struct bch_sb_field_members *mi;
1444         unsigned dev_idx = ca->dev_idx, data;
1445         int ret;
1446
1447         down_write(&c->state_lock);
1448
1449         /*
1450          * We consume a reference to ca->ref, regardless of whether we succeed
1451          * or fail:
1452          */
1453         percpu_ref_put(&ca->ref);
1454
1455         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1456                 bch_err(ca, "Cannot remove without losing data");
1457                 ret = -BCH_ERR_device_state_not_allowed;
1458                 goto err;
1459         }
1460
1461         __bch2_dev_read_only(c, ca);
1462
1463         ret = bch2_dev_data_drop(c, ca->dev_idx, flags);
1464         if (ret) {
1465                 bch_err(ca, "Remove failed: error dropping data: %s", bch2_err_str(ret));
1466                 goto err;
1467         }
1468
1469         ret = bch2_dev_remove_alloc(c, ca);
1470         if (ret) {
1471                 bch_err(ca, "Remove failed, error deleting alloc info");
1472                 goto err;
1473         }
1474
1475         ret = bch2_journal_flush_device_pins(&c->journal, ca->dev_idx);
1476         if (ret) {
1477                 bch_err(ca, "Remove failed: error flushing journal: %s", bch2_err_str(ret));
1478                 goto err;
1479         }
1480
1481         ret = bch2_journal_flush(&c->journal);
1482         if (ret) {
1483                 bch_err(ca, "Remove failed, journal error");
1484                 goto err;
1485         }
1486
1487         ret = bch2_replicas_gc2(c);
1488         if (ret) {
1489                 bch_err(ca, "Remove failed: error from replicas gc: %s", bch2_err_str(ret));
1490                 goto err;
1491         }
1492
1493         data = bch2_dev_has_data(c, ca);
1494         if (data) {
1495                 struct printbuf data_has = PRINTBUF;
1496
1497                 prt_bitflags(&data_has, bch2_data_types, data);
1498                 bch_err(ca, "Remove failed, still has data (%s)", data_has.buf);
1499                 printbuf_exit(&data_has);
1500                 ret = -EBUSY;
1501                 goto err;
1502         }
1503
1504         __bch2_dev_offline(c, ca);
1505
1506         mutex_lock(&c->sb_lock);
1507         rcu_assign_pointer(c->devs[ca->dev_idx], NULL);
1508         mutex_unlock(&c->sb_lock);
1509
1510         percpu_ref_kill(&ca->ref);
1511         wait_for_completion(&ca->ref_completion);
1512
1513         bch2_dev_free(ca);
1514
1515         /*
1516          * Free this device's slot in the bch_member array - all pointers to
1517          * this device must be gone:
1518          */
1519         mutex_lock(&c->sb_lock);
1520         mi = bch2_sb_get_members(c->disk_sb.sb);
1521         memset(&mi->members[dev_idx].uuid, 0, sizeof(mi->members[dev_idx].uuid));
1522
1523         bch2_write_super(c);
1524
1525         mutex_unlock(&c->sb_lock);
1526         up_write(&c->state_lock);
1527
1528         bch2_dev_usage_journal_reserve(c);
1529         return 0;
1530 err:
1531         if (ca->mi.state == BCH_MEMBER_STATE_rw &&
1532             !percpu_ref_is_zero(&ca->io_ref))
1533                 __bch2_dev_read_write(c, ca);
1534         up_write(&c->state_lock);
1535         return ret;
1536 }
1537
1538 /* Add new device to running filesystem: */
1539 int bch2_dev_add(struct bch_fs *c, const char *path)
1540 {
1541         struct bch_opts opts = bch2_opts_empty();
1542         struct bch_sb_handle sb;
1543         struct bch_dev *ca = NULL;
1544         struct bch_sb_field_members *mi;
1545         struct bch_member dev_mi;
1546         unsigned dev_idx, nr_devices, u64s;
1547         struct printbuf errbuf = PRINTBUF;
1548         struct printbuf label = PRINTBUF;
1549         int ret;
1550
1551         ret = bch2_read_super(path, &opts, &sb);
1552         if (ret) {
1553                 bch_err(c, "device add error: error reading super: %s", bch2_err_str(ret));
1554                 goto err;
1555         }
1556
1557         dev_mi = bch2_sb_get_members(sb.sb)->members[sb.sb->dev_idx];
1558
1559         if (BCH_MEMBER_GROUP(&dev_mi)) {
1560                 bch2_disk_path_to_text(&label, sb.sb, BCH_MEMBER_GROUP(&dev_mi) - 1);
1561                 if (label.allocation_failure) {
1562                         ret = -ENOMEM;
1563                         goto err;
1564                 }
1565         }
1566
1567         ret = bch2_dev_may_add(sb.sb, c);
1568         if (ret) {
1569                 bch_err(c, "device add error: %s", bch2_err_str(ret));
1570                 goto err;
1571         }
1572
1573         ca = __bch2_dev_alloc(c, &dev_mi);
1574         if (!ca) {
1575                 bch2_free_super(&sb);
1576                 ret = -ENOMEM;
1577                 goto err;
1578         }
1579
1580         bch2_dev_usage_init(ca);
1581
1582         ret = __bch2_dev_attach_bdev(ca, &sb);
1583         if (ret) {
1584                 bch2_dev_free(ca);
1585                 goto err;
1586         }
1587
1588         ret = bch2_dev_journal_alloc(ca);
1589         if (ret) {
1590                 bch_err(c, "device add error: journal alloc failed");
1591                 goto err;
1592         }
1593
1594         down_write(&c->state_lock);
1595         mutex_lock(&c->sb_lock);
1596
1597         ret = bch2_sb_from_fs(c, ca);
1598         if (ret) {
1599                 bch_err(c, "device add error: new device superblock too small");
1600                 goto err_unlock;
1601         }
1602
1603         mi = bch2_sb_get_members(ca->disk_sb.sb);
1604
1605         if (!bch2_sb_resize_members(&ca->disk_sb,
1606                                 le32_to_cpu(mi->field.u64s) +
1607                                 sizeof(dev_mi) / sizeof(u64))) {
1608                 bch_err(c, "device add error: new device superblock too small");
1609                 ret = -BCH_ERR_ENOSPC_sb_members;
1610                 goto err_unlock;
1611         }
1612
1613         if (dynamic_fault("bcachefs:add:no_slot"))
1614                 goto no_slot;
1615
1616         mi = bch2_sb_get_members(c->disk_sb.sb);
1617         for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
1618                 if (!bch2_dev_exists(c->disk_sb.sb, mi, dev_idx))
1619                         goto have_slot;
1620 no_slot:
1621         bch_err(c, "device add error: already have maximum number of devices");
1622         ret = -BCH_ERR_ENOSPC_sb_members;
1623         goto err_unlock;
1624
1625 have_slot:
1626         nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
1627         u64s = (sizeof(struct bch_sb_field_members) +
1628                 sizeof(struct bch_member) * nr_devices) / sizeof(u64);
1629
1630         mi = bch2_sb_resize_members(&c->disk_sb, u64s);
1631         if (!mi) {
1632                 bch_err(c, "device add error: no room in superblock for member info");
1633                 ret = -BCH_ERR_ENOSPC_sb_members;
1634                 goto err_unlock;
1635         }
1636
1637         /* success: */
1638
1639         mi->members[dev_idx] = dev_mi;
1640         mi->members[dev_idx].last_mount = cpu_to_le64(ktime_get_real_seconds());
1641         c->disk_sb.sb->nr_devices       = nr_devices;
1642
1643         ca->disk_sb.sb->dev_idx = dev_idx;
1644         bch2_dev_attach(c, ca, dev_idx);
1645
1646         if (BCH_MEMBER_GROUP(&dev_mi)) {
1647                 ret = __bch2_dev_group_set(c, ca, label.buf);
1648                 if (ret) {
1649                         bch_err(c, "device add error: error setting label");
1650                         goto err_unlock;
1651                 }
1652         }
1653
1654         bch2_write_super(c);
1655         mutex_unlock(&c->sb_lock);
1656
1657         bch2_dev_usage_journal_reserve(c);
1658
1659         ret = bch2_trans_mark_dev_sb(c, ca);
1660         if (ret) {
1661                 bch_err(c, "device add error: error marking new superblock: %s", bch2_err_str(ret));
1662                 goto err_late;
1663         }
1664
1665         ret = bch2_fs_freespace_init(c);
1666         if (ret) {
1667                 bch_err(c, "device add error: error initializing free space: %s", bch2_err_str(ret));
1668                 goto err_late;
1669         }
1670
1671         ca->new_fs_bucket_idx = 0;
1672
1673         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1674                 __bch2_dev_read_write(c, ca);
1675
1676         up_write(&c->state_lock);
1677         return 0;
1678
1679 err_unlock:
1680         mutex_unlock(&c->sb_lock);
1681         up_write(&c->state_lock);
1682 err:
1683         if (ca)
1684                 bch2_dev_free(ca);
1685         bch2_free_super(&sb);
1686         printbuf_exit(&label);
1687         printbuf_exit(&errbuf);
1688         return ret;
1689 err_late:
1690         up_write(&c->state_lock);
1691         ca = NULL;
1692         goto err;
1693 }
1694
1695 /* Hot add existing device to running filesystem: */
1696 int bch2_dev_online(struct bch_fs *c, const char *path)
1697 {
1698         struct bch_opts opts = bch2_opts_empty();
1699         struct bch_sb_handle sb = { NULL };
1700         struct bch_sb_field_members *mi;
1701         struct bch_dev *ca;
1702         unsigned dev_idx;
1703         int ret;
1704
1705         down_write(&c->state_lock);
1706
1707         ret = bch2_read_super(path, &opts, &sb);
1708         if (ret) {
1709                 up_write(&c->state_lock);
1710                 return ret;
1711         }
1712
1713         dev_idx = sb.sb->dev_idx;
1714
1715         ret = bch2_dev_in_fs(c->disk_sb.sb, sb.sb);
1716         if (ret) {
1717                 bch_err(c, "error bringing %s online: %s", path, bch2_err_str(ret));
1718                 goto err;
1719         }
1720
1721         ret = bch2_dev_attach_bdev(c, &sb);
1722         if (ret)
1723                 goto err;
1724
1725         ca = bch_dev_locked(c, dev_idx);
1726
1727         ret = bch2_trans_mark_dev_sb(c, ca);
1728         if (ret) {
1729                 bch_err(c, "error bringing %s online: error from bch2_trans_mark_dev_sb: %s",
1730                         path, bch2_err_str(ret));
1731                 goto err;
1732         }
1733
1734         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1735                 __bch2_dev_read_write(c, ca);
1736
1737         mutex_lock(&c->sb_lock);
1738         mi = bch2_sb_get_members(c->disk_sb.sb);
1739
1740         mi->members[ca->dev_idx].last_mount =
1741                 cpu_to_le64(ktime_get_real_seconds());
1742
1743         bch2_write_super(c);
1744         mutex_unlock(&c->sb_lock);
1745
1746         up_write(&c->state_lock);
1747         return 0;
1748 err:
1749         up_write(&c->state_lock);
1750         bch2_free_super(&sb);
1751         return ret;
1752 }
1753
1754 int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
1755 {
1756         down_write(&c->state_lock);
1757
1758         if (!bch2_dev_is_online(ca)) {
1759                 bch_err(ca, "Already offline");
1760                 up_write(&c->state_lock);
1761                 return 0;
1762         }
1763
1764         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1765                 bch_err(ca, "Cannot offline required disk");
1766                 up_write(&c->state_lock);
1767                 return -BCH_ERR_device_state_not_allowed;
1768         }
1769
1770         __bch2_dev_offline(c, ca);
1771
1772         up_write(&c->state_lock);
1773         return 0;
1774 }
1775
1776 int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
1777 {
1778         struct bch_member *mi;
1779         int ret = 0;
1780
1781         down_write(&c->state_lock);
1782
1783         if (nbuckets < ca->mi.nbuckets) {
1784                 bch_err(ca, "Cannot shrink yet");
1785                 ret = -EINVAL;
1786                 goto err;
1787         }
1788
1789         if (bch2_dev_is_online(ca) &&
1790             get_capacity(ca->disk_sb.bdev->bd_disk) <
1791             ca->mi.bucket_size * nbuckets) {
1792                 bch_err(ca, "New size larger than device");
1793                 ret = -BCH_ERR_device_size_too_small;
1794                 goto err;
1795         }
1796
1797         ret = bch2_dev_buckets_resize(c, ca, nbuckets);
1798         if (ret) {
1799                 bch_err(ca, "Resize error: %s", bch2_err_str(ret));
1800                 goto err;
1801         }
1802
1803         ret = bch2_trans_mark_dev_sb(c, ca);
1804         if (ret)
1805                 goto err;
1806
1807         mutex_lock(&c->sb_lock);
1808         mi = &bch2_sb_get_members(c->disk_sb.sb)->members[ca->dev_idx];
1809         mi->nbuckets = cpu_to_le64(nbuckets);
1810
1811         bch2_write_super(c);
1812         mutex_unlock(&c->sb_lock);
1813
1814         bch2_recalc_capacity(c);
1815 err:
1816         up_write(&c->state_lock);
1817         return ret;
1818 }
1819
1820 /* return with ref on ca->ref: */
1821 struct bch_dev *bch2_dev_lookup(struct bch_fs *c, const char *name)
1822 {
1823         struct bch_dev *ca;
1824         unsigned i;
1825
1826         rcu_read_lock();
1827         for_each_member_device_rcu(ca, c, i, NULL)
1828                 if (!strcmp(name, ca->name))
1829                         goto found;
1830         ca = ERR_PTR(-ENOENT);
1831 found:
1832         rcu_read_unlock();
1833
1834         return ca;
1835 }
1836
1837 /* Filesystem open: */
1838
1839 struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
1840                             struct bch_opts opts)
1841 {
1842         struct bch_sb_handle *sb = NULL;
1843         struct bch_fs *c = NULL;
1844         struct bch_sb_field_members *mi;
1845         unsigned i, best_sb = 0;
1846         struct printbuf errbuf = PRINTBUF;
1847         int ret = 0;
1848
1849         if (!try_module_get(THIS_MODULE))
1850                 return ERR_PTR(-ENODEV);
1851
1852         pr_verbose_init(opts, "");
1853
1854         if (!nr_devices) {
1855                 ret = -EINVAL;
1856                 goto err;
1857         }
1858
1859         sb = kcalloc(nr_devices, sizeof(*sb), GFP_KERNEL);
1860         if (!sb) {
1861                 ret = -ENOMEM;
1862                 goto err;
1863         }
1864
1865         for (i = 0; i < nr_devices; i++) {
1866                 ret = bch2_read_super(devices[i], &opts, &sb[i]);
1867                 if (ret)
1868                         goto err;
1869
1870         }
1871
1872         for (i = 1; i < nr_devices; i++)
1873                 if (le64_to_cpu(sb[i].sb->seq) >
1874                     le64_to_cpu(sb[best_sb].sb->seq))
1875                         best_sb = i;
1876
1877         mi = bch2_sb_get_members(sb[best_sb].sb);
1878
1879         i = 0;
1880         while (i < nr_devices) {
1881                 if (i != best_sb &&
1882                     !bch2_dev_exists(sb[best_sb].sb, mi, sb[i].sb->dev_idx)) {
1883                         pr_info("%pg has been removed, skipping", sb[i].bdev);
1884                         bch2_free_super(&sb[i]);
1885                         array_remove_item(sb, nr_devices, i);
1886                         continue;
1887                 }
1888
1889                 ret = bch2_dev_in_fs(sb[best_sb].sb, sb[i].sb);
1890                 if (ret)
1891                         goto err_print;
1892                 i++;
1893         }
1894
1895         c = bch2_fs_alloc(sb[best_sb].sb, opts);
1896         if (IS_ERR(c)) {
1897                 ret = PTR_ERR(c);
1898                 goto err;
1899         }
1900
1901         down_write(&c->state_lock);
1902         for (i = 0; i < nr_devices; i++) {
1903                 ret = bch2_dev_attach_bdev(c, &sb[i]);
1904                 if (ret) {
1905                         up_write(&c->state_lock);
1906                         goto err;
1907                 }
1908         }
1909         up_write(&c->state_lock);
1910
1911         if (!bch2_fs_may_start(c)) {
1912                 ret = -BCH_ERR_insufficient_devices_to_start;
1913                 goto err_print;
1914         }
1915
1916         if (!c->opts.nostart) {
1917                 ret = bch2_fs_start(c);
1918                 if (ret)
1919                         goto err;
1920         }
1921 out:
1922         kfree(sb);
1923         printbuf_exit(&errbuf);
1924         module_put(THIS_MODULE);
1925         pr_verbose_init(opts, "ret %s (%i)", bch2_err_str(PTR_ERR_OR_ZERO(c)),
1926                         PTR_ERR_OR_ZERO(c));
1927         return c;
1928 err_print:
1929         pr_err("bch_fs_open err opening %s: %s",
1930                devices[0], bch2_err_str(ret));
1931 err:
1932         if (!IS_ERR_OR_NULL(c))
1933                 bch2_fs_stop(c);
1934         if (sb)
1935                 for (i = 0; i < nr_devices; i++)
1936                         bch2_free_super(&sb[i]);
1937         c = ERR_PTR(ret);
1938         goto out;
1939 }
1940
1941 /* Global interfaces/init */
1942
1943 static void bcachefs_exit(void)
1944 {
1945         bch2_debug_exit();
1946         bch2_vfs_exit();
1947         bch2_chardev_exit();
1948         bch2_btree_key_cache_exit();
1949         if (bcachefs_kset)
1950                 kset_unregister(bcachefs_kset);
1951 }
1952
1953 static int __init bcachefs_init(void)
1954 {
1955         bch2_bkey_pack_test();
1956
1957         if (!(bcachefs_kset = kset_create_and_add("bcachefs", NULL, fs_kobj)) ||
1958             bch2_btree_key_cache_init() ||
1959             bch2_chardev_init() ||
1960             bch2_vfs_init() ||
1961             bch2_debug_init())
1962                 goto err;
1963
1964         return 0;
1965 err:
1966         bcachefs_exit();
1967         return -ENOMEM;
1968 }
1969
1970 #define BCH_DEBUG_PARAM(name, description)                      \
1971         bool bch2_##name;                                       \
1972         module_param_named(name, bch2_##name, bool, 0644);      \
1973         MODULE_PARM_DESC(name, description);
1974 BCH_DEBUG_PARAMS()
1975 #undef BCH_DEBUG_PARAM
1976
1977 unsigned bch2_metadata_version = bcachefs_metadata_version_current;
1978 module_param_named(version, bch2_metadata_version, uint, 0400);
1979
1980 module_exit(bcachefs_exit);
1981 module_init(bcachefs_init);