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_journal_iter.h"
  17 #include "btree_key_cache.h"
  18 #include "btree_update_interior.h"
  19 #include "btree_io.h"
  20 #include "btree_write_buffer.h"
  21 #include "buckets_waiting_for_journal.h"
  22 #include "chardev.h"
  23 #include "checksum.h"
  24 #include "clock.h"
  25 #include "compress.h"
  26 #include "counters.h"
  27 #include "debug.h"
  28 #include "disk_groups.h"
  29 #include "ec.h"
  30 #include "errcode.h"
  31 #include "error.h"
  32 #include "fs.h"
  33 #include "fs-io.h"
  34 #include "fs-io-buffered.h"
  35 #include "fs-io-direct.h"
  36 #include "fsck.h"
  37 #include "inode.h"
  38 #include "io.h"
  39 #include "journal.h"
  40 #include "journal_reclaim.h"
  41 #include "journal_seq_blacklist.h"
  42 #include "move.h"
  43 #include "migrate.h"
  44 #include "movinggc.h"
  45 #include "nocow_locking.h"
  46 #include "quota.h"
  47 #include "rebalance.h"
  48 #include "recovery.h"
  49 #include "replicas.h"
  50 #include "sb-clean.h"
  51 #include "snapshot.h"
  52 #include "subvolume.h"
  53 #include "super.h"
  54 #include "super-io.h"
  55 #include "sysfs.h"
  56 #include "trace.h"
  57
  58 #include <linux/backing-dev.h>
  59 #include <linux/blkdev.h>
  60 #include <linux/debugfs.h>
  61 #include <linux/device.h>
  62 #include <linux/idr.h>
  63 #include <linux/module.h>
  64 #include <linux/percpu.h>
  65 #include <linux/random.h>
  66 #include <linux/sysfs.h>
  67 #include <crypto/hash.h>
  68
  69 MODULE_LICENSE("GPL");
  70 MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
  71
  72 #define KTYPE(type)                                                     \
  73 static const struct attribute_group type ## _group = {                  \
  74         .attrs = type ## _files                                         \
  75 };                                                                      \
  76                                                                         \
  77 static const struct attribute_group *type ## _groups[] = {              \
  78         &type ## _group,                                                \
  79         NULL                                                            \
  80 };                                                                      \
  81                                                                         \
  82 static const struct kobj_type type ## _ktype = {                        \
  83         .release        = type ## _release,                             \
  84         .sysfs_ops      = &type ## _sysfs_ops,                          \
  85         .default_groups = type ## _groups                               \
  86 }
  87
  88 static void bch2_fs_release(struct kobject *);
  89 static void bch2_dev_release(struct kobject *);
  90 static void bch2_fs_counters_release(struct kobject *k)
  91 {
  92 }
  93
  94 static void bch2_fs_internal_release(struct kobject *k)
  95 {
  96 }
  97
  98 static void bch2_fs_opts_dir_release(struct kobject *k)
  99 {
 100 }
 101
 102 static void bch2_fs_time_stats_release(struct kobject *k)
 103 {
 104 }
 105
 106 KTYPE(bch2_fs);
 107 KTYPE(bch2_fs_counters);
 108 KTYPE(bch2_fs_internal);
 109 KTYPE(bch2_fs_opts_dir);
 110 KTYPE(bch2_fs_time_stats);
 111 KTYPE(bch2_dev);
 112
 113 static struct kset *bcachefs_kset;
 114 static LIST_HEAD(bch_fs_list);
 115 static DEFINE_MUTEX(bch_fs_list_lock);
 116
 117 DECLARE_WAIT_QUEUE_HEAD(bch2_read_only_wait);
 118
 119 static void bch2_dev_free(struct bch_dev *);
 120 static int bch2_dev_alloc(struct bch_fs *, unsigned);
 121 static int bch2_dev_sysfs_online(struct bch_fs *, struct bch_dev *);
 122 static void __bch2_dev_read_only(struct bch_fs *, struct bch_dev *);
 123
 124 struct bch_fs *bch2_dev_to_fs(dev_t dev)
 125 {
 126         struct bch_fs *c;
 127         struct bch_dev *ca;
 128         unsigned i;
 129
 130         mutex_lock(&bch_fs_list_lock);
 131         rcu_read_lock();
 132
 133         list_for_each_entry(c, &bch_fs_list, list)
 134                 for_each_member_device_rcu(ca, c, i, NULL)
 135                         if (ca->disk_sb.bdev && ca->disk_sb.bdev->bd_dev == dev) {
 136                                 closure_get(&c->cl);
 137                                 goto found;
 138                         }
 139         c = NULL;
 140 found:
 141         rcu_read_unlock();
 142         mutex_unlock(&bch_fs_list_lock);
 143
 144         return c;
 145 }
 146
 147 static struct bch_fs *__bch2_uuid_to_fs(__uuid_t uuid)
 148 {
 149         struct bch_fs *c;
 150
 151         lockdep_assert_held(&bch_fs_list_lock);
 152
 153         list_for_each_entry(c, &bch_fs_list, list)
 154                 if (!memcmp(&c->disk_sb.sb->uuid, &uuid, sizeof(uuid)))
 155                         return c;
 156
 157         return NULL;
 158 }
 159
 160 struct bch_fs *bch2_uuid_to_fs(__uuid_t uuid)
 161 {
 162         struct bch_fs *c;
 163
 164         mutex_lock(&bch_fs_list_lock);
 165         c = __bch2_uuid_to_fs(uuid);
 166         if (c)
 167                 closure_get(&c->cl);
 168         mutex_unlock(&bch_fs_list_lock);
 169
 170         return c;
 171 }
 172
 173 static void bch2_dev_usage_journal_reserve(struct bch_fs *c)
 174 {
 175         struct bch_dev *ca;
 176         unsigned i, nr = 0, u64s =
 177                 ((sizeof(struct jset_entry_dev_usage) +
 178                   sizeof(struct jset_entry_dev_usage_type) * BCH_DATA_NR)) /
 179                 sizeof(u64);
 180
 181         rcu_read_lock();
 182         for_each_member_device_rcu(ca, c, i, NULL)
 183                 nr++;
 184         rcu_read_unlock();
 185
 186         bch2_journal_entry_res_resize(&c->journal,
 187                         &c->dev_usage_journal_res, u64s * nr);
 188 }
 189
 190 /* Filesystem RO/RW: */
 191
 192 /*
 193  * For startup/shutdown of RW stuff, the dependencies are:
 194  *
 195  * - foreground writes depend on copygc and rebalance (to free up space)
 196  *
 197  * - copygc and rebalance depend on mark and sweep gc (they actually probably
 198  *   don't because they either reserve ahead of time or don't block if
 199  *   allocations fail, but allocations can require mark and sweep gc to run
 200  *   because of generation number wraparound)
 201  *
 202  * - all of the above depends on the allocator threads
 203  *
 204  * - allocator depends on the journal (when it rewrites prios and gens)
 205  */
 206
 207 static void __bch2_fs_read_only(struct bch_fs *c)
 208 {
 209         struct bch_dev *ca;
 210         unsigned i, clean_passes = 0;
 211         u64 seq = 0;
 212
 213         bch2_fs_ec_stop(c);
 214         bch2_open_buckets_stop(c, NULL, true);
 215         bch2_rebalance_stop(c);
 216         bch2_copygc_stop(c);
 217         bch2_gc_thread_stop(c);
 218         bch2_fs_ec_flush(c);
 219
 220         bch_verbose(c, "flushing journal and stopping allocators, journal seq %llu",
 221                     journal_cur_seq(&c->journal));
 222
 223         do {
 224                 clean_passes++;
 225
 226                 if (bch2_btree_interior_updates_flush(c) ||
 227                     bch2_journal_flush_all_pins(&c->journal) ||
 228                     bch2_btree_flush_all_writes(c) ||
 229                     seq != atomic64_read(&c->journal.seq)) {
 230                         seq = atomic64_read(&c->journal.seq);
 231                         clean_passes = 0;
 232                 }
 233         } while (clean_passes < 2);
 234
 235         bch_verbose(c, "flushing journal and stopping allocators complete, journal seq %llu",
 236                     journal_cur_seq(&c->journal));
 237
 238         if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
 239             !test_bit(BCH_FS_EMERGENCY_RO, &c->flags))
 240                 set_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
 241         bch2_fs_journal_stop(&c->journal);
 242
 243         /*
 244          * After stopping journal:
 245          */
 246         for_each_member_device(ca, c, i)
 247                 bch2_dev_allocator_remove(c, ca);
 248 }
 249
 250 #ifndef BCH_WRITE_REF_DEBUG
 251 static void bch2_writes_disabled(struct percpu_ref *writes)
 252 {
 253         struct bch_fs *c = container_of(writes, struct bch_fs, writes);
 254
 255         set_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
 256         wake_up(&bch2_read_only_wait);
 257 }
 258 #endif
 259
 260 void bch2_fs_read_only(struct bch_fs *c)
 261 {
 262         if (!test_bit(BCH_FS_RW, &c->flags)) {
 263                 bch2_journal_reclaim_stop(&c->journal);
 264                 return;
 265         }
 266
 267         BUG_ON(test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags));
 268
 269         /*
 270          * Block new foreground-end write operations from starting - any new
 271          * writes will return -EROFS:
 272          */
 273         set_bit(BCH_FS_GOING_RO, &c->flags);
 274 #ifndef BCH_WRITE_REF_DEBUG
 275         percpu_ref_kill(&c->writes);
 276 #else
 277         for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++)
 278                 bch2_write_ref_put(c, i);
 279 #endif
 280
 281         /*
 282          * If we're not doing an emergency shutdown, we want to wait on
 283          * outstanding writes to complete so they don't see spurious errors due
 284          * to shutting down the allocator:
 285          *
 286          * If we are doing an emergency shutdown outstanding writes may
 287          * hang until we shutdown the allocator so we don't want to wait
 288          * on outstanding writes before shutting everything down - but
 289          * we do need to wait on them before returning and signalling
 290          * that going RO is complete:
 291          */
 292         wait_event(bch2_read_only_wait,
 293                    test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags) ||
 294                    test_bit(BCH_FS_EMERGENCY_RO, &c->flags));
 295
 296         __bch2_fs_read_only(c);
 297
 298         wait_event(bch2_read_only_wait,
 299                    test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags));
 300
 301         clear_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
 302         clear_bit(BCH_FS_GOING_RO, &c->flags);
 303
 304         if (!bch2_journal_error(&c->journal) &&
 305             !test_bit(BCH_FS_ERROR, &c->flags) &&
 306             !test_bit(BCH_FS_EMERGENCY_RO, &c->flags) &&
 307             test_bit(BCH_FS_STARTED, &c->flags) &&
 308             test_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags) &&
 309             !c->opts.norecovery) {
 310                 BUG_ON(c->journal.last_empty_seq != journal_cur_seq(&c->journal));
 311                 BUG_ON(atomic_read(&c->btree_cache.dirty));
 312                 BUG_ON(atomic_long_read(&c->btree_key_cache.nr_dirty));
 313                 BUG_ON(c->btree_write_buffer.state.nr);
 314
 315                 bch_verbose(c, "marking filesystem clean");
 316                 bch2_fs_mark_clean(c);
 317         }
 318
 319         clear_bit(BCH_FS_RW, &c->flags);
 320 }
 321
 322 static void bch2_fs_read_only_work(struct work_struct *work)
 323 {
 324         struct bch_fs *c =
 325                 container_of(work, struct bch_fs, read_only_work);
 326
 327         down_write(&c->state_lock);
 328         bch2_fs_read_only(c);
 329         up_write(&c->state_lock);
 330 }
 331
 332 static void bch2_fs_read_only_async(struct bch_fs *c)
 333 {
 334         queue_work(system_long_wq, &c->read_only_work);
 335 }
 336
 337 bool bch2_fs_emergency_read_only(struct bch_fs *c)
 338 {
 339         bool ret = !test_and_set_bit(BCH_FS_EMERGENCY_RO, &c->flags);
 340
 341         bch2_journal_halt(&c->journal);
 342         bch2_fs_read_only_async(c);
 343
 344         wake_up(&bch2_read_only_wait);
 345         return ret;
 346 }
 347
 348 static int bch2_fs_read_write_late(struct bch_fs *c)
 349 {
 350         int ret;
 351
 352         /*
 353          * Data move operations can't run until after check_snapshots has
 354          * completed, and bch2_snapshot_is_ancestor() is available.
 355          *
 356          * Ideally we'd start copygc/rebalance earlier instead of waiting for
 357          * all of recovery/fsck to complete:
 358          */
 359         ret = bch2_copygc_start(c);
 360         if (ret) {
 361                 bch_err(c, "error starting copygc thread");
 362                 return ret;
 363         }
 364
 365         ret = bch2_rebalance_start(c);
 366         if (ret) {
 367                 bch_err(c, "error starting rebalance thread");
 368                 return ret;
 369         }
 370
 371         return 0;
 372 }
 373
 374 static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 375 {
 376         struct bch_dev *ca;
 377         unsigned i;
 378         int ret;
 379
 380         if (test_bit(BCH_FS_INITIAL_GC_UNFIXED, &c->flags)) {
 381                 bch_err(c, "cannot go rw, unfixed btree errors");
 382                 return -BCH_ERR_erofs_unfixed_errors;
 383         }
 384
 385         if (test_bit(BCH_FS_RW, &c->flags))
 386                 return 0;
 387
 388         if (c->opts.norecovery)
 389                 return -BCH_ERR_erofs_norecovery;
 390
 391         /*
 392          * nochanges is used for fsck -n mode - we have to allow going rw
 393          * during recovery for that to work:
 394          */
 395         if (c->opts.nochanges && (!early || c->opts.read_only))
 396                 return -BCH_ERR_erofs_nochanges;
 397
 398         bch_info(c, "going read-write");
 399
 400         ret = bch2_fs_mark_dirty(c);
 401         if (ret)
 402                 goto err;
 403
 404         clear_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
 405
 406         /*
 407          * First journal write must be a flush write: after a clean shutdown we
 408          * don't read the journal, so the first journal write may end up
 409          * overwriting whatever was there previously, and there must always be
 410          * at least one non-flush write in the journal or recovery will fail:
 411          */
 412         set_bit(JOURNAL_NEED_FLUSH_WRITE, &c->journal.flags);
 413
 414         for_each_rw_member(ca, c, i)
 415                 bch2_dev_allocator_add(c, ca);
 416         bch2_recalc_capacity(c);
 417
 418         ret = bch2_gc_thread_start(c);
 419         if (ret) {
 420                 bch_err(c, "error starting gc thread");
 421                 return ret;
 422         }
 423
 424         if (!early) {
 425                 ret = bch2_fs_read_write_late(c);
 426                 if (ret)
 427                         goto err;
 428         }
 429
 430 #ifndef BCH_WRITE_REF_DEBUG
 431         percpu_ref_reinit(&c->writes);
 432 #else
 433         for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) {
 434                 BUG_ON(atomic_long_read(&c->writes[i]));
 435                 atomic_long_inc(&c->writes[i]);
 436         }
 437 #endif
 438         set_bit(BCH_FS_RW, &c->flags);
 439         set_bit(BCH_FS_WAS_RW, &c->flags);
 440
 441         bch2_do_discards(c);
 442         bch2_do_invalidates(c);
 443         bch2_do_stripe_deletes(c);
 444         bch2_do_pending_node_rewrites(c);
 445         return 0;
 446 err:
 447         __bch2_fs_read_only(c);
 448         return ret;
 449 }
 450
 451 int bch2_fs_read_write(struct bch_fs *c)
 452 {
 453         return __bch2_fs_read_write(c, false);
 454 }
 455
 456 int bch2_fs_read_write_early(struct bch_fs *c)
 457 {
 458         lockdep_assert_held(&c->state_lock);
 459
 460         return __bch2_fs_read_write(c, true);
 461 }
 462
 463 /* Filesystem startup/shutdown: */
 464
 465 static void __bch2_fs_free(struct bch_fs *c)
 466 {
 467         unsigned i;
 468         int cpu;
 469
 470         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 471                 bch2_time_stats_exit(&c->times[i]);
 472
 473         bch2_free_pending_node_rewrites(c);
 474         bch2_fs_counters_exit(c);
 475         bch2_fs_snapshots_exit(c);
 476         bch2_fs_quota_exit(c);
 477         bch2_fs_fs_io_direct_exit(c);
 478         bch2_fs_fs_io_buffered_exit(c);
 479         bch2_fs_fsio_exit(c);
 480         bch2_fs_ec_exit(c);
 481         bch2_fs_encryption_exit(c);
 482         bch2_fs_io_exit(c);
 483         bch2_fs_buckets_waiting_for_journal_exit(c);
 484         bch2_fs_btree_interior_update_exit(c);
 485         bch2_fs_btree_iter_exit(c);
 486         bch2_fs_btree_key_cache_exit(&c->btree_key_cache);
 487         bch2_fs_btree_cache_exit(c);
 488         bch2_fs_replicas_exit(c);
 489         bch2_fs_journal_exit(&c->journal);
 490         bch2_io_clock_exit(&c->io_clock[WRITE]);
 491         bch2_io_clock_exit(&c->io_clock[READ]);
 492         bch2_fs_compress_exit(c);
 493         bch2_journal_keys_free(&c->journal_keys);
 494         bch2_journal_entries_free(c);
 495         bch2_fs_btree_write_buffer_exit(c);
 496         percpu_free_rwsem(&c->mark_lock);
 497         free_percpu(c->online_reserved);
 498
 499         if (c->btree_paths_bufs)
 500                 for_each_possible_cpu(cpu)
 501                         kfree(per_cpu_ptr(c->btree_paths_bufs, cpu)->path);
 502
 503         darray_exit(&c->btree_roots_extra);
 504         free_percpu(c->btree_paths_bufs);
 505         free_percpu(c->pcpu);
 506         mempool_exit(&c->large_bkey_pool);
 507         mempool_exit(&c->btree_bounce_pool);
 508         bioset_exit(&c->btree_bio);
 509         mempool_exit(&c->fill_iter);
 510 #ifndef BCH_WRITE_REF_DEBUG
 511         percpu_ref_exit(&c->writes);
 512 #endif
 513         kfree(rcu_dereference_protected(c->disk_groups, 1));
 514         kfree(c->journal_seq_blacklist_table);
 515         kfree(c->unused_inode_hints);
 516
 517         if (c->write_ref_wq)
 518                 destroy_workqueue(c->write_ref_wq);
 519         if (c->io_complete_wq)
 520                 destroy_workqueue(c->io_complete_wq);
 521         if (c->copygc_wq)
 522                 destroy_workqueue(c->copygc_wq);
 523         if (c->btree_io_complete_wq)
 524                 destroy_workqueue(c->btree_io_complete_wq);
 525         if (c->btree_update_wq)
 526                 destroy_workqueue(c->btree_update_wq);
 527
 528         bch2_free_super(&c->disk_sb);
 529         kvpfree(c, sizeof(*c));
 530         module_put(THIS_MODULE);
 531 }
 532
 533 static void bch2_fs_release(struct kobject *kobj)
 534 {
 535         struct bch_fs *c = container_of(kobj, struct bch_fs, kobj);
 536
 537         __bch2_fs_free(c);
 538 }
 539
 540 void __bch2_fs_stop(struct bch_fs *c)
 541 {
 542         struct bch_dev *ca;
 543         unsigned i;
 544
 545         bch_verbose(c, "shutting down");
 546
 547         set_bit(BCH_FS_STOPPING, &c->flags);
 548
 549         cancel_work_sync(&c->journal_seq_blacklist_gc_work);
 550
 551         down_write(&c->state_lock);
 552         bch2_fs_read_only(c);
 553         up_write(&c->state_lock);
 554
 555         for_each_member_device(ca, c, i)
 556                 if (ca->kobj.state_in_sysfs &&
 557                     ca->disk_sb.bdev)
 558                         sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
 559
 560         if (c->kobj.state_in_sysfs)
 561                 kobject_del(&c->kobj);
 562
 563         bch2_fs_debug_exit(c);
 564         bch2_fs_chardev_exit(c);
 565
 566         kobject_put(&c->counters_kobj);
 567         kobject_put(&c->time_stats);
 568         kobject_put(&c->opts_dir);
 569         kobject_put(&c->internal);
 570
 571         /* btree prefetch might have kicked off reads in the background: */
 572         bch2_btree_flush_all_reads(c);
 573
 574         for_each_member_device(ca, c, i)
 575                 cancel_work_sync(&ca->io_error_work);
 576
 577         cancel_work_sync(&c->read_only_work);
 578 }
 579
 580 void bch2_fs_free(struct bch_fs *c)
 581 {
 582         unsigned i;
 583
 584         mutex_lock(&bch_fs_list_lock);
 585         list_del(&c->list);
 586         mutex_unlock(&bch_fs_list_lock);
 587
 588         closure_sync(&c->cl);
 589         closure_debug_destroy(&c->cl);
 590
 591         for (i = 0; i < c->sb.nr_devices; i++) {
 592                 struct bch_dev *ca = rcu_dereference_protected(c->devs[i], true);
 593
 594                 if (ca) {
 595                         bch2_free_super(&ca->disk_sb);
 596                         bch2_dev_free(ca);
 597                 }
 598         }
 599
 600         bch_verbose(c, "shutdown complete");
 601
 602         kobject_put(&c->kobj);
 603 }
 604
 605 void bch2_fs_stop(struct bch_fs *c)
 606 {
 607         __bch2_fs_stop(c);
 608         bch2_fs_free(c);
 609 }
 610
 611 static int bch2_fs_online(struct bch_fs *c)
 612 {
 613         struct bch_dev *ca;
 614         unsigned i;
 615         int ret = 0;
 616
 617         lockdep_assert_held(&bch_fs_list_lock);
 618
 619         if (__bch2_uuid_to_fs(c->sb.uuid)) {
 620                 bch_err(c, "filesystem UUID already open");
 621                 return -EINVAL;
 622         }
 623
 624         ret = bch2_fs_chardev_init(c);
 625         if (ret) {
 626                 bch_err(c, "error creating character device");
 627                 return ret;
 628         }
 629
 630         bch2_fs_debug_init(c);
 631
 632         ret = kobject_add(&c->kobj, NULL, "%pU", c->sb.user_uuid.b) ?:
 633             kobject_add(&c->internal, &c->kobj, "internal") ?:
 634             kobject_add(&c->opts_dir, &c->kobj, "options") ?:
 635             kobject_add(&c->time_stats, &c->kobj, "time_stats") ?:
 636             kobject_add(&c->counters_kobj, &c->kobj, "counters") ?:
 637             bch2_opts_create_sysfs_files(&c->opts_dir);
 638         if (ret) {
 639                 bch_err(c, "error creating sysfs objects");
 640                 return ret;
 641         }
 642
 643         down_write(&c->state_lock);
 644
 645         for_each_member_device(ca, c, i) {
 646                 ret = bch2_dev_sysfs_online(c, ca);
 647                 if (ret) {
 648                         bch_err(c, "error creating sysfs objects");
 649                         percpu_ref_put(&ca->ref);
 650                         goto err;
 651                 }
 652         }
 653
 654         BUG_ON(!list_empty(&c->list));
 655         list_add(&c->list, &bch_fs_list);
 656 err:
 657         up_write(&c->state_lock);
 658         return ret;
 659 }
 660
 661 static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 662 {
 663         struct bch_sb_field_members *mi;
 664         struct bch_fs *c;
 665         struct printbuf name = PRINTBUF;
 666         unsigned i, iter_size;
 667         int ret = 0;
 668
 669         c = kvpmalloc(sizeof(struct bch_fs), GFP_KERNEL|__GFP_ZERO);
 670         if (!c) {
 671                 c = ERR_PTR(-BCH_ERR_ENOMEM_fs_alloc);
 672                 goto out;
 673         }
 674
 675         __module_get(THIS_MODULE);
 676
 677         closure_init(&c->cl, NULL);
 678
 679         c->kobj.kset = bcachefs_kset;
 680         kobject_init(&c->kobj, &bch2_fs_ktype);
 681         kobject_init(&c->internal, &bch2_fs_internal_ktype);
 682         kobject_init(&c->opts_dir, &bch2_fs_opts_dir_ktype);
 683         kobject_init(&c->time_stats, &bch2_fs_time_stats_ktype);
 684         kobject_init(&c->counters_kobj, &bch2_fs_counters_ktype);
 685
 686         c->minor                = -1;
 687         c->disk_sb.fs_sb        = true;
 688
 689         init_rwsem(&c->state_lock);
 690         mutex_init(&c->sb_lock);
 691         mutex_init(&c->replicas_gc_lock);
 692         mutex_init(&c->btree_root_lock);
 693         INIT_WORK(&c->read_only_work, bch2_fs_read_only_work);
 694
 695         init_rwsem(&c->gc_lock);
 696         mutex_init(&c->gc_gens_lock);
 697
 698         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 699                 bch2_time_stats_init(&c->times[i]);
 700
 701         bch2_fs_copygc_init(c);
 702         bch2_fs_btree_key_cache_init_early(&c->btree_key_cache);
 703         bch2_fs_btree_interior_update_init_early(c);
 704         bch2_fs_allocator_background_init(c);
 705         bch2_fs_allocator_foreground_init(c);
 706         bch2_fs_rebalance_init(c);
 707         bch2_fs_quota_init(c);
 708         bch2_fs_ec_init_early(c);
 709         bch2_fs_move_init(c);
 710
 711         INIT_LIST_HEAD(&c->list);
 712
 713         mutex_init(&c->usage_scratch_lock);
 714
 715         mutex_init(&c->bio_bounce_pages_lock);
 716         mutex_init(&c->snapshot_table_lock);
 717
 718         spin_lock_init(&c->btree_write_error_lock);
 719
 720         INIT_WORK(&c->journal_seq_blacklist_gc_work,
 721                   bch2_blacklist_entries_gc);
 722
 723         INIT_LIST_HEAD(&c->journal_iters);
 724
 725         INIT_LIST_HEAD(&c->fsck_errors);
 726         mutex_init(&c->fsck_error_lock);
 727
 728         seqcount_init(&c->gc_pos_lock);
 729
 730         seqcount_init(&c->usage_lock);
 731
 732         sema_init(&c->io_in_flight, 128);
 733
 734         INIT_LIST_HEAD(&c->vfs_inodes_list);
 735         mutex_init(&c->vfs_inodes_lock);
 736
 737         c->copy_gc_enabled              = 1;
 738         c->rebalance.enabled            = 1;
 739         c->promote_whole_extents        = true;
 740
 741         c->journal.flush_write_time     = &c->times[BCH_TIME_journal_flush_write];
 742         c->journal.noflush_write_time   = &c->times[BCH_TIME_journal_noflush_write];
 743         c->journal.blocked_time         = &c->times[BCH_TIME_blocked_journal];
 744         c->journal.flush_seq_time       = &c->times[BCH_TIME_journal_flush_seq];
 745
 746         bch2_fs_btree_cache_init_early(&c->btree_cache);
 747
 748         mutex_init(&c->sectors_available_lock);
 749
 750         ret = percpu_init_rwsem(&c->mark_lock);
 751         if (ret)
 752                 goto err;
 753
 754         mutex_lock(&c->sb_lock);
 755         ret = bch2_sb_to_fs(c, sb);
 756         mutex_unlock(&c->sb_lock);
 757
 758         if (ret)
 759                 goto err;
 760
 761         pr_uuid(&name, c->sb.user_uuid.b);
 762         strscpy(c->name, name.buf, sizeof(c->name));
 763         printbuf_exit(&name);
 764
 765         ret = name.allocation_failure ? -BCH_ERR_ENOMEM_fs_name_alloc : 0;
 766         if (ret)
 767                 goto err;
 768
 769         /* Compat: */
 770         if (le16_to_cpu(sb->version) <= bcachefs_metadata_version_inode_v2 &&
 771             !BCH_SB_JOURNAL_FLUSH_DELAY(sb))
 772                 SET_BCH_SB_JOURNAL_FLUSH_DELAY(sb, 1000);
 773
 774         if (le16_to_cpu(sb->version) <= bcachefs_metadata_version_inode_v2 &&
 775             !BCH_SB_JOURNAL_RECLAIM_DELAY(sb))
 776                 SET_BCH_SB_JOURNAL_RECLAIM_DELAY(sb, 100);
 777
 778         c->opts = bch2_opts_default;
 779         ret = bch2_opts_from_sb(&c->opts, sb);
 780         if (ret)
 781                 goto err;
 782
 783         bch2_opts_apply(&c->opts, opts);
 784
 785         c->btree_key_cache_btrees |= 1U << BTREE_ID_alloc;
 786         if (c->opts.inodes_use_key_cache)
 787                 c->btree_key_cache_btrees |= 1U << BTREE_ID_inodes;
 788
 789         c->block_bits           = ilog2(block_sectors(c));
 790         c->btree_foreground_merge_threshold = BTREE_FOREGROUND_MERGE_THRESHOLD(c);
 791
 792         if (bch2_fs_init_fault("fs_alloc")) {
 793                 bch_err(c, "fs_alloc fault injected");
 794                 ret = -EFAULT;
 795                 goto err;
 796         }
 797
 798         iter_size = sizeof(struct sort_iter) +
 799                 (btree_blocks(c) + 1) * 2 *
 800                 sizeof(struct sort_iter_set);
 801
 802         c->inode_shard_bits = ilog2(roundup_pow_of_two(num_possible_cpus()));
 803
 804         if (!(c->btree_update_wq = alloc_workqueue("bcachefs",
 805                                 WQ_FREEZABLE|WQ_UNBOUND|WQ_MEM_RECLAIM, 512)) ||
 806             !(c->btree_io_complete_wq = alloc_workqueue("bcachefs_btree_io",
 807                                 WQ_FREEZABLE|WQ_MEM_RECLAIM, 1)) ||
 808             !(c->copygc_wq = alloc_workqueue("bcachefs_copygc",
 809                                 WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
 810             !(c->io_complete_wq = alloc_workqueue("bcachefs_io",
 811                                 WQ_FREEZABLE|WQ_HIGHPRI|WQ_MEM_RECLAIM, 1)) ||
 812             !(c->write_ref_wq = alloc_workqueue("bcachefs_write_ref",
 813                                 WQ_FREEZABLE, 0)) ||
 814 #ifndef BCH_WRITE_REF_DEBUG
 815             percpu_ref_init(&c->writes, bch2_writes_disabled,
 816                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
 817 #endif
 818             mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
 819             bioset_init(&c->btree_bio, 1,
 820                         max(offsetof(struct btree_read_bio, bio),
 821                             offsetof(struct btree_write_bio, wbio.bio)),
 822                         BIOSET_NEED_BVECS) ||
 823             !(c->pcpu = alloc_percpu(struct bch_fs_pcpu)) ||
 824             !(c->online_reserved = alloc_percpu(u64)) ||
 825             !(c->btree_paths_bufs = alloc_percpu(struct btree_path_buf)) ||
 826             mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
 827                                         btree_bytes(c)) ||
 828             mempool_init_kmalloc_pool(&c->large_bkey_pool, 1, 2048) ||
 829             !(c->unused_inode_hints = kcalloc(1U << c->inode_shard_bits,
 830                                               sizeof(u64), GFP_KERNEL))) {
 831                 ret = -BCH_ERR_ENOMEM_fs_other_alloc;
 832                 goto err;
 833         }
 834
 835         ret = bch2_fs_counters_init(c) ?:
 836             bch2_io_clock_init(&c->io_clock[READ]) ?:
 837             bch2_io_clock_init(&c->io_clock[WRITE]) ?:
 838             bch2_fs_journal_init(&c->journal) ?:
 839             bch2_fs_replicas_init(c) ?:
 840             bch2_fs_btree_cache_init(c) ?:
 841             bch2_fs_btree_key_cache_init(&c->btree_key_cache) ?:
 842             bch2_fs_btree_iter_init(c) ?:
 843             bch2_fs_btree_interior_update_init(c) ?:
 844             bch2_fs_buckets_waiting_for_journal_init(c) ?:
 845             bch2_fs_btree_write_buffer_init(c) ?:
 846             bch2_fs_subvolumes_init(c) ?:
 847             bch2_fs_io_init(c) ?:
 848             bch2_fs_nocow_locking_init(c) ?:
 849             bch2_fs_encryption_init(c) ?:
 850             bch2_fs_compress_init(c) ?:
 851             bch2_fs_ec_init(c) ?:
 852             bch2_fs_fsio_init(c) ?:
 853             bch2_fs_fs_io_buffered_init(c);
 854             bch2_fs_fs_io_direct_init(c);
 855         if (ret)
 856                 goto err;
 857
 858         mi = bch2_sb_get_members(c->disk_sb.sb);
 859         for (i = 0; i < c->sb.nr_devices; i++)
 860                 if (bch2_dev_exists(c->disk_sb.sb, mi, i) &&
 861                     bch2_dev_alloc(c, i)) {
 862                         ret = -EEXIST;
 863                         goto err;
 864                 }
 865
 866         bch2_journal_entry_res_resize(&c->journal,
 867                         &c->btree_root_journal_res,
 868                         BTREE_ID_NR * (JSET_KEYS_U64s + BKEY_BTREE_PTR_U64s_MAX));
 869         bch2_dev_usage_journal_reserve(c);
 870         bch2_journal_entry_res_resize(&c->journal,
 871                         &c->clock_journal_res,
 872                         (sizeof(struct jset_entry_clock) / sizeof(u64)) * 2);
 873
 874         mutex_lock(&bch_fs_list_lock);
 875         ret = bch2_fs_online(c);
 876         mutex_unlock(&bch_fs_list_lock);
 877
 878         if (ret)
 879                 goto err;
 880 out:
 881         return c;
 882 err:
 883         bch2_fs_free(c);
 884         c = ERR_PTR(ret);
 885         goto out;
 886 }
 887
 888 noinline_for_stack
 889 static void print_mount_opts(struct bch_fs *c)
 890 {
 891         enum bch_opt_id i;
 892         struct printbuf p = PRINTBUF;
 893         bool first = true;
 894
 895         prt_str(&p, "mounting version ");
 896         bch2_version_to_text(&p, c->sb.version);
 897
 898         if (c->opts.read_only) {
 899                 prt_str(&p, " opts=");
 900                 first = false;
 901                 prt_printf(&p, "ro");
 902         }
 903
 904         for (i = 0; i < bch2_opts_nr; i++) {
 905                 const struct bch_option *opt = &bch2_opt_table[i];
 906                 u64 v = bch2_opt_get_by_id(&c->opts, i);
 907
 908                 if (!(opt->flags & OPT_MOUNT))
 909                         continue;
 910
 911                 if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
 912                         continue;
 913
 914                 prt_str(&p, first ? " opts=" : ",");
 915                 first = false;
 916                 bch2_opt_to_text(&p, c, c->disk_sb.sb, opt, v, OPT_SHOW_MOUNT_STYLE);
 917         }
 918
 919         bch_info(c, "%s", p.buf);
 920         printbuf_exit(&p);
 921 }
 922
 923 int bch2_fs_start(struct bch_fs *c)
 924 {
 925         struct bch_sb_field_members *mi;
 926         struct bch_dev *ca;
 927         time64_t now = ktime_get_real_seconds();
 928         unsigned i;
 929         int ret;
 930
 931         print_mount_opts(c);
 932
 933         down_write(&c->state_lock);
 934
 935         BUG_ON(test_bit(BCH_FS_STARTED, &c->flags));
 936
 937         mutex_lock(&c->sb_lock);
 938
 939         for_each_online_member(ca, c, i)
 940                 bch2_sb_from_fs(c, ca);
 941
 942         mi = bch2_sb_get_members(c->disk_sb.sb);
 943         for_each_online_member(ca, c, i)
 944                 mi->members[ca->dev_idx].last_mount = cpu_to_le64(now);
 945
 946         mutex_unlock(&c->sb_lock);
 947
 948         for_each_rw_member(ca, c, i)
 949                 bch2_dev_allocator_add(c, ca);
 950         bch2_recalc_capacity(c);
 951
 952         for (i = 0; i < BCH_TRANSACTIONS_NR; i++) {
 953                 mutex_lock(&c->btree_transaction_stats[i].lock);
 954                 bch2_time_stats_init(&c->btree_transaction_stats[i].lock_hold_times);
 955                 mutex_unlock(&c->btree_transaction_stats[i].lock);
 956         }
 957
 958         ret = BCH_SB_INITIALIZED(c->disk_sb.sb)
 959                 ? bch2_fs_recovery(c)
 960                 : bch2_fs_initialize(c);
 961         if (ret)
 962                 goto err;
 963
 964         ret = bch2_opts_check_may_set(c);
 965         if (ret)
 966                 goto err;
 967
 968         if (bch2_fs_init_fault("fs_start")) {
 969                 bch_err(c, "fs_start fault injected");
 970                 ret = -EINVAL;
 971                 goto err;
 972         }
 973
 974         set_bit(BCH_FS_STARTED, &c->flags);
 975
 976         if (c->opts.read_only || c->opts.nochanges) {
 977                 bch2_fs_read_only(c);
 978         } else {
 979                 ret = !test_bit(BCH_FS_RW, &c->flags)
 980                         ? bch2_fs_read_write(c)
 981                         : bch2_fs_read_write_late(c);
 982                 if (ret)
 983                         goto err;
 984         }
 985
 986         ret = 0;
 987 out:
 988         up_write(&c->state_lock);
 989         return ret;
 990 err:
 991         bch_err(c, "error starting filesystem: %s", bch2_err_str(ret));
 992         goto out;
 993 }
 994
 995 static int bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
 996 {
 997         struct bch_sb_field_members *sb_mi;
 998
 999         sb_mi = bch2_sb_get_members(sb);
1000         if (!sb_mi)
1001                 return -BCH_ERR_member_info_missing;
1002
1003         if (le16_to_cpu(sb->block_size) != block_sectors(c))
1004                 return -BCH_ERR_mismatched_block_size;
1005
1006         if (le16_to_cpu(sb_mi->members[sb->dev_idx].bucket_size) <
1007             BCH_SB_BTREE_NODE_SIZE(c->disk_sb.sb))
1008                 return -BCH_ERR_bucket_size_too_small;
1009
1010         return 0;
1011 }
1012
1013 static int bch2_dev_in_fs(struct bch_sb *fs, struct bch_sb *sb)
1014 {
1015         struct bch_sb *newest =
1016                 le64_to_cpu(fs->seq) > le64_to_cpu(sb->seq) ? fs : sb;
1017         struct bch_sb_field_members *mi = bch2_sb_get_members(newest);
1018
1019         if (!uuid_equal(&fs->uuid, &sb->uuid))
1020                 return -BCH_ERR_device_not_a_member_of_filesystem;
1021
1022         if (!bch2_dev_exists(newest, mi, sb->dev_idx))
1023                 return -BCH_ERR_device_has_been_removed;
1024
1025         if (fs->block_size != sb->block_size)
1026                 return -BCH_ERR_mismatched_block_size;
1027
1028         return 0;
1029 }
1030
1031 /* Device startup/shutdown: */
1032
1033 static void bch2_dev_release(struct kobject *kobj)
1034 {
1035         struct bch_dev *ca = container_of(kobj, struct bch_dev, kobj);
1036
1037         kfree(ca);
1038 }
1039
1040 static void bch2_dev_free(struct bch_dev *ca)
1041 {
1042         cancel_work_sync(&ca->io_error_work);
1043
1044         if (ca->kobj.state_in_sysfs &&
1045             ca->disk_sb.bdev)
1046                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1047
1048         if (ca->kobj.state_in_sysfs)
1049                 kobject_del(&ca->kobj);
1050
1051         bch2_free_super(&ca->disk_sb);
1052         bch2_dev_journal_exit(ca);
1053
1054         free_percpu(ca->io_done);
1055         bioset_exit(&ca->replica_set);
1056         bch2_dev_buckets_free(ca);
1057         free_page((unsigned long) ca->sb_read_scratch);
1058
1059         bch2_time_stats_exit(&ca->io_latency[WRITE]);
1060         bch2_time_stats_exit(&ca->io_latency[READ]);
1061
1062         percpu_ref_exit(&ca->io_ref);
1063         percpu_ref_exit(&ca->ref);
1064         kobject_put(&ca->kobj);
1065 }
1066
1067 static void __bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca)
1068 {
1069
1070         lockdep_assert_held(&c->state_lock);
1071
1072         if (percpu_ref_is_zero(&ca->io_ref))
1073                 return;
1074
1075         __bch2_dev_read_only(c, ca);
1076
1077         reinit_completion(&ca->io_ref_completion);
1078         percpu_ref_kill(&ca->io_ref);
1079         wait_for_completion(&ca->io_ref_completion);
1080
1081         if (ca->kobj.state_in_sysfs) {
1082                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1083                 sysfs_remove_link(&ca->kobj, "block");
1084         }
1085
1086         bch2_free_super(&ca->disk_sb);
1087         bch2_dev_journal_exit(ca);
1088 }
1089
1090 static void bch2_dev_ref_complete(struct percpu_ref *ref)
1091 {
1092         struct bch_dev *ca = container_of(ref, struct bch_dev, ref);
1093
1094         complete(&ca->ref_completion);
1095 }
1096
1097 static void bch2_dev_io_ref_complete(struct percpu_ref *ref)
1098 {
1099         struct bch_dev *ca = container_of(ref, struct bch_dev, io_ref);
1100
1101         complete(&ca->io_ref_completion);
1102 }
1103
1104 static int bch2_dev_sysfs_online(struct bch_fs *c, struct bch_dev *ca)
1105 {
1106         int ret;
1107
1108         if (!c->kobj.state_in_sysfs)
1109                 return 0;
1110
1111         if (!ca->kobj.state_in_sysfs) {
1112                 ret = kobject_add(&ca->kobj, &c->kobj,
1113                                   "dev-%u", ca->dev_idx);
1114                 if (ret)
1115                         return ret;
1116         }
1117
1118         if (ca->disk_sb.bdev) {
1119                 struct kobject *block = bdev_kobj(ca->disk_sb.bdev);
1120
1121                 ret = sysfs_create_link(block, &ca->kobj, "bcachefs");
1122                 if (ret)
1123                         return ret;
1124
1125                 ret = sysfs_create_link(&ca->kobj, block, "block");
1126                 if (ret)
1127                         return ret;
1128         }
1129
1130         return 0;
1131 }
1132
1133 static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
1134                                         struct bch_member *member)
1135 {
1136         struct bch_dev *ca;
1137
1138         ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1139         if (!ca)
1140                 return NULL;
1141
1142         kobject_init(&ca->kobj, &bch2_dev_ktype);
1143         init_completion(&ca->ref_completion);
1144         init_completion(&ca->io_ref_completion);
1145
1146         init_rwsem(&ca->bucket_lock);
1147
1148         INIT_WORK(&ca->io_error_work, bch2_io_error_work);
1149
1150         bch2_time_stats_init(&ca->io_latency[READ]);
1151         bch2_time_stats_init(&ca->io_latency[WRITE]);
1152
1153         ca->mi = bch2_mi_to_cpu(member);
1154         ca->uuid = member->uuid;
1155
1156         ca->nr_btree_reserve = DIV_ROUND_UP(BTREE_NODE_RESERVE,
1157                              ca->mi.bucket_size / btree_sectors(c));
1158
1159         if (percpu_ref_init(&ca->ref, bch2_dev_ref_complete,
1160                             0, GFP_KERNEL) ||
1161             percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
1162                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
1163             !(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
1164             bch2_dev_buckets_alloc(c, ca) ||
1165             bioset_init(&ca->replica_set, 4,
1166                         offsetof(struct bch_write_bio, bio), 0) ||
1167             !(ca->io_done       = alloc_percpu(*ca->io_done)))
1168                 goto err;
1169
1170         return ca;
1171 err:
1172         bch2_dev_free(ca);
1173         return NULL;
1174 }
1175
1176 static void bch2_dev_attach(struct bch_fs *c, struct bch_dev *ca,
1177                             unsigned dev_idx)
1178 {
1179         ca->dev_idx = dev_idx;
1180         __set_bit(ca->dev_idx, ca->self.d);
1181         scnprintf(ca->name, sizeof(ca->name), "dev-%u", dev_idx);
1182
1183         ca->fs = c;
1184         rcu_assign_pointer(c->devs[ca->dev_idx], ca);
1185
1186         if (bch2_dev_sysfs_online(c, ca))
1187                 pr_warn("error creating sysfs objects");
1188 }
1189
1190 static int bch2_dev_alloc(struct bch_fs *c, unsigned dev_idx)
1191 {
1192         struct bch_member *member =
1193                 bch2_sb_get_members(c->disk_sb.sb)->members + dev_idx;
1194         struct bch_dev *ca = NULL;
1195         int ret = 0;
1196
1197         if (bch2_fs_init_fault("dev_alloc"))
1198                 goto err;
1199
1200         ca = __bch2_dev_alloc(c, member);
1201         if (!ca)
1202                 goto err;
1203
1204         ca->fs = c;
1205
1206         bch2_dev_attach(c, ca, dev_idx);
1207         return ret;
1208 err:
1209         if (ca)
1210                 bch2_dev_free(ca);
1211         return -BCH_ERR_ENOMEM_dev_alloc;
1212 }
1213
1214 static int __bch2_dev_attach_bdev(struct bch_dev *ca, struct bch_sb_handle *sb)
1215 {
1216         unsigned ret;
1217
1218         if (bch2_dev_is_online(ca)) {
1219                 bch_err(ca, "already have device online in slot %u",
1220                         sb->sb->dev_idx);
1221                 return -BCH_ERR_device_already_online;
1222         }
1223
1224         if (get_capacity(sb->bdev->bd_disk) <
1225             ca->mi.bucket_size * ca->mi.nbuckets) {
1226                 bch_err(ca, "cannot online: device too small");
1227                 return -BCH_ERR_device_size_too_small;
1228         }
1229
1230         BUG_ON(!percpu_ref_is_zero(&ca->io_ref));
1231
1232         ret = bch2_dev_journal_init(ca, sb->sb);
1233         if (ret)
1234                 return ret;
1235
1236         /* Commit: */
1237         ca->disk_sb = *sb;
1238         if (sb->mode & FMODE_EXCL)
1239                 ca->disk_sb.bdev->bd_holder = ca;
1240         memset(sb, 0, sizeof(*sb));
1241
1242         ca->dev = ca->disk_sb.bdev->bd_dev;
1243
1244         percpu_ref_reinit(&ca->io_ref);
1245
1246         return 0;
1247 }
1248
1249 static int bch2_dev_attach_bdev(struct bch_fs *c, struct bch_sb_handle *sb)
1250 {
1251         struct bch_dev *ca;
1252         int ret;
1253
1254         lockdep_assert_held(&c->state_lock);
1255
1256         if (le64_to_cpu(sb->sb->seq) >
1257             le64_to_cpu(c->disk_sb.sb->seq))
1258                 bch2_sb_to_fs(c, sb->sb);
1259
1260         BUG_ON(sb->sb->dev_idx >= c->sb.nr_devices ||
1261                !c->devs[sb->sb->dev_idx]);
1262
1263         ca = bch_dev_locked(c, sb->sb->dev_idx);
1264
1265         ret = __bch2_dev_attach_bdev(ca, sb);
1266         if (ret)
1267                 return ret;
1268
1269         bch2_dev_sysfs_online(c, ca);
1270
1271         if (c->sb.nr_devices == 1)
1272                 snprintf(c->name, sizeof(c->name), "%pg", ca->disk_sb.bdev);
1273         snprintf(ca->name, sizeof(ca->name), "%pg", ca->disk_sb.bdev);
1274
1275         rebalance_wakeup(c);
1276         return 0;
1277 }
1278
1279 /* Device management: */
1280
1281 /*
1282  * Note: this function is also used by the error paths - when a particular
1283  * device sees an error, we call it to determine whether we can just set the
1284  * device RO, or - if this function returns false - we'll set the whole
1285  * filesystem RO:
1286  *
1287  * XXX: maybe we should be more explicit about whether we're changing state
1288  * because we got an error or what have you?
1289  */
1290 bool bch2_dev_state_allowed(struct bch_fs *c, struct bch_dev *ca,
1291                             enum bch_member_state new_state, int flags)
1292 {
1293         struct bch_devs_mask new_online_devs;
1294         struct bch_dev *ca2;
1295         int i, nr_rw = 0, required;
1296
1297         lockdep_assert_held(&c->state_lock);
1298
1299         switch (new_state) {
1300         case BCH_MEMBER_STATE_rw:
1301                 return true;
1302         case BCH_MEMBER_STATE_ro:
1303                 if (ca->mi.state != BCH_MEMBER_STATE_rw)
1304                         return true;
1305
1306                 /* do we have enough devices to write to?  */
1307                 for_each_member_device(ca2, c, i)
1308                         if (ca2 != ca)
1309                                 nr_rw += ca2->mi.state == BCH_MEMBER_STATE_rw;
1310
1311                 required = max(!(flags & BCH_FORCE_IF_METADATA_DEGRADED)
1312                                ? c->opts.metadata_replicas
1313                                : c->opts.metadata_replicas_required,
1314                                !(flags & BCH_FORCE_IF_DATA_DEGRADED)
1315                                ? c->opts.data_replicas
1316                                : c->opts.data_replicas_required);
1317
1318                 return nr_rw >= required;
1319         case BCH_MEMBER_STATE_failed:
1320         case BCH_MEMBER_STATE_spare:
1321                 if (ca->mi.state != BCH_MEMBER_STATE_rw &&
1322                     ca->mi.state != BCH_MEMBER_STATE_ro)
1323                         return true;
1324
1325                 /* do we have enough devices to read from?  */
1326                 new_online_devs = bch2_online_devs(c);
1327                 __clear_bit(ca->dev_idx, new_online_devs.d);
1328
1329                 return bch2_have_enough_devs(c, new_online_devs, flags, false);
1330         default:
1331                 BUG();
1332         }
1333 }
1334
1335 static bool bch2_fs_may_start(struct bch_fs *c)
1336 {
1337         struct bch_sb_field_members *mi;
1338         struct bch_dev *ca;
1339         unsigned i, flags = 0;
1340
1341         if (c->opts.very_degraded)
1342                 flags |= BCH_FORCE_IF_DEGRADED|BCH_FORCE_IF_LOST;
1343
1344         if (c->opts.degraded)
1345                 flags |= BCH_FORCE_IF_DEGRADED;
1346
1347         if (!c->opts.degraded &&
1348             !c->opts.very_degraded) {
1349                 mutex_lock(&c->sb_lock);
1350                 mi = bch2_sb_get_members(c->disk_sb.sb);
1351
1352                 for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
1353                         if (!bch2_dev_exists(c->disk_sb.sb, mi, i))
1354                                 continue;
1355
1356                         ca = bch_dev_locked(c, i);
1357
1358                         if (!bch2_dev_is_online(ca) &&
1359                             (ca->mi.state == BCH_MEMBER_STATE_rw ||
1360                              ca->mi.state == BCH_MEMBER_STATE_ro)) {
1361                                 mutex_unlock(&c->sb_lock);
1362                                 return false;
1363                         }
1364                 }
1365                 mutex_unlock(&c->sb_lock);
1366         }
1367
1368         return bch2_have_enough_devs(c, bch2_online_devs(c), flags, true);
1369 }
1370
1371 static void __bch2_dev_read_only(struct bch_fs *c, struct bch_dev *ca)
1372 {
1373         /*
1374          * The allocator thread itself allocates btree nodes, so stop it first:
1375          */
1376         bch2_dev_allocator_remove(c, ca);
1377         bch2_dev_journal_stop(&c->journal, ca);
1378 }
1379
1380 static void __bch2_dev_read_write(struct bch_fs *c, struct bch_dev *ca)
1381 {
1382         lockdep_assert_held(&c->state_lock);
1383
1384         BUG_ON(ca->mi.state != BCH_MEMBER_STATE_rw);
1385
1386         bch2_dev_allocator_add(c, ca);
1387         bch2_recalc_capacity(c);
1388 }
1389
1390 int __bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1391                          enum bch_member_state new_state, int flags)
1392 {
1393         struct bch_sb_field_members *mi;
1394         int ret = 0;
1395
1396         if (ca->mi.state == new_state)
1397                 return 0;
1398
1399         if (!bch2_dev_state_allowed(c, ca, new_state, flags))
1400                 return -BCH_ERR_device_state_not_allowed;
1401
1402         if (new_state != BCH_MEMBER_STATE_rw)
1403                 __bch2_dev_read_only(c, ca);
1404
1405         bch_notice(ca, "%s", bch2_member_states[new_state]);
1406
1407         mutex_lock(&c->sb_lock);
1408         mi = bch2_sb_get_members(c->disk_sb.sb);
1409         SET_BCH_MEMBER_STATE(&mi->members[ca->dev_idx], new_state);
1410         bch2_write_super(c);
1411         mutex_unlock(&c->sb_lock);
1412
1413         if (new_state == BCH_MEMBER_STATE_rw)
1414                 __bch2_dev_read_write(c, ca);
1415
1416         rebalance_wakeup(c);
1417
1418         return ret;
1419 }
1420
1421 int bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1422                        enum bch_member_state new_state, int flags)
1423 {
1424         int ret;
1425
1426         down_write(&c->state_lock);
1427         ret = __bch2_dev_set_state(c, ca, new_state, flags);
1428         up_write(&c->state_lock);
1429
1430         return ret;
1431 }
1432
1433 /* Device add/removal: */
1434
1435 static int bch2_dev_remove_alloc(struct bch_fs *c, struct bch_dev *ca)
1436 {
1437         struct bpos start       = POS(ca->dev_idx, 0);
1438         struct bpos end         = POS(ca->dev_idx, U64_MAX);
1439         int ret;
1440
1441         /*
1442          * We clear the LRU and need_discard btrees first so that we don't race
1443          * with bch2_do_invalidates() and bch2_do_discards()
1444          */
1445         ret =   bch2_btree_delete_range(c, BTREE_ID_lru, start, end,
1446                                         BTREE_TRIGGER_NORUN, NULL) ?:
1447                 bch2_btree_delete_range(c, BTREE_ID_need_discard, start, end,
1448                                         BTREE_TRIGGER_NORUN, NULL) ?:
1449                 bch2_btree_delete_range(c, BTREE_ID_freespace, start, end,
1450                                         BTREE_TRIGGER_NORUN, NULL) ?:
1451                 bch2_btree_delete_range(c, BTREE_ID_backpointers, start, end,
1452                                         BTREE_TRIGGER_NORUN, NULL) ?:
1453                 bch2_btree_delete_range(c, BTREE_ID_alloc, start, end,
1454                                         BTREE_TRIGGER_NORUN, NULL) ?:
1455                 bch2_btree_delete_range(c, BTREE_ID_bucket_gens, start, end,
1456                                         BTREE_TRIGGER_NORUN, NULL);
1457         if (ret)
1458                 bch_err(c, "error removing dev alloc info: %s", bch2_err_str(ret));
1459
1460         return ret;
1461 }
1462
1463 int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
1464 {
1465         struct bch_sb_field_members *mi;
1466         unsigned dev_idx = ca->dev_idx, data;
1467         int ret;
1468
1469         down_write(&c->state_lock);
1470
1471         /*
1472          * We consume a reference to ca->ref, regardless of whether we succeed
1473          * or fail:
1474          */
1475         percpu_ref_put(&ca->ref);
1476
1477         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1478                 bch_err(ca, "Cannot remove without losing data");
1479                 ret = -BCH_ERR_device_state_not_allowed;
1480                 goto err;
1481         }
1482
1483         __bch2_dev_read_only(c, ca);
1484
1485         ret = bch2_dev_data_drop(c, ca->dev_idx, flags);
1486         if (ret) {
1487                 bch_err(ca, "Remove failed: error dropping data: %s", bch2_err_str(ret));
1488                 goto err;
1489         }
1490
1491         ret = bch2_dev_remove_alloc(c, ca);
1492         if (ret) {
1493                 bch_err(ca, "Remove failed, error deleting alloc info");
1494                 goto err;
1495         }
1496
1497         ret = bch2_journal_flush_device_pins(&c->journal, ca->dev_idx);
1498         if (ret) {
1499                 bch_err(ca, "Remove failed: error flushing journal: %s", bch2_err_str(ret));
1500                 goto err;
1501         }
1502
1503         ret = bch2_journal_flush(&c->journal);
1504         if (ret) {
1505                 bch_err(ca, "Remove failed, journal error");
1506                 goto err;
1507         }
1508
1509         ret = bch2_replicas_gc2(c);
1510         if (ret) {
1511                 bch_err(ca, "Remove failed: error from replicas gc: %s", bch2_err_str(ret));
1512                 goto err;
1513         }
1514
1515         data = bch2_dev_has_data(c, ca);
1516         if (data) {
1517                 struct printbuf data_has = PRINTBUF;
1518
1519                 prt_bitflags(&data_has, bch2_data_types, data);
1520                 bch_err(ca, "Remove failed, still has data (%s)", data_has.buf);
1521                 printbuf_exit(&data_has);
1522                 ret = -EBUSY;
1523                 goto err;
1524         }
1525
1526         __bch2_dev_offline(c, ca);
1527
1528         mutex_lock(&c->sb_lock);
1529         rcu_assign_pointer(c->devs[ca->dev_idx], NULL);
1530         mutex_unlock(&c->sb_lock);
1531
1532         percpu_ref_kill(&ca->ref);
1533         wait_for_completion(&ca->ref_completion);
1534
1535         bch2_dev_free(ca);
1536
1537         /*
1538          * At this point the device object has been removed in-core, but the
1539          * on-disk journal might still refer to the device index via sb device
1540          * usage entries. Recovery fails if it sees usage information for an
1541          * invalid device. Flush journal pins to push the back of the journal
1542          * past now invalid device index references before we update the
1543          * superblock, but after the device object has been removed so any
1544          * further journal writes elide usage info for the device.
1545          */
1546         bch2_journal_flush_all_pins(&c->journal);
1547
1548         /*
1549          * Free this device's slot in the bch_member array - all pointers to
1550          * this device must be gone:
1551          */
1552         mutex_lock(&c->sb_lock);
1553         mi = bch2_sb_get_members(c->disk_sb.sb);
1554         memset(&mi->members[dev_idx].uuid, 0, sizeof(mi->members[dev_idx].uuid));
1555
1556         bch2_write_super(c);
1557
1558         mutex_unlock(&c->sb_lock);
1559         up_write(&c->state_lock);
1560
1561         bch2_dev_usage_journal_reserve(c);
1562         return 0;
1563 err:
1564         if (ca->mi.state == BCH_MEMBER_STATE_rw &&
1565             !percpu_ref_is_zero(&ca->io_ref))
1566                 __bch2_dev_read_write(c, ca);
1567         up_write(&c->state_lock);
1568         return ret;
1569 }
1570
1571 /* Add new device to running filesystem: */
1572 int bch2_dev_add(struct bch_fs *c, const char *path)
1573 {
1574         struct bch_opts opts = bch2_opts_empty();
1575         struct bch_sb_handle sb;
1576         struct bch_dev *ca = NULL;
1577         struct bch_sb_field_members *mi;
1578         struct bch_member dev_mi;
1579         unsigned dev_idx, nr_devices, u64s;
1580         struct printbuf errbuf = PRINTBUF;
1581         struct printbuf label = PRINTBUF;
1582         int ret;
1583
1584         ret = bch2_read_super(path, &opts, &sb);
1585         if (ret) {
1586                 bch_err(c, "device add error: error reading super: %s", bch2_err_str(ret));
1587                 goto err;
1588         }
1589
1590         dev_mi = bch2_sb_get_members(sb.sb)->members[sb.sb->dev_idx];
1591
1592         if (BCH_MEMBER_GROUP(&dev_mi)) {
1593                 bch2_disk_path_to_text(&label, sb.sb, BCH_MEMBER_GROUP(&dev_mi) - 1);
1594                 if (label.allocation_failure) {
1595                         ret = -ENOMEM;
1596                         goto err;
1597                 }
1598         }
1599
1600         ret = bch2_dev_may_add(sb.sb, c);
1601         if (ret) {
1602                 bch_err(c, "device add error: %s", bch2_err_str(ret));
1603                 goto err;
1604         }
1605
1606         ca = __bch2_dev_alloc(c, &dev_mi);
1607         if (!ca) {
1608                 bch2_free_super(&sb);
1609                 ret = -ENOMEM;
1610                 goto err;
1611         }
1612
1613         bch2_dev_usage_init(ca);
1614
1615         ret = __bch2_dev_attach_bdev(ca, &sb);
1616         if (ret) {
1617                 bch2_dev_free(ca);
1618                 goto err;
1619         }
1620
1621         ret = bch2_dev_journal_alloc(ca);
1622         if (ret) {
1623                 bch_err(c, "device add error: journal alloc failed");
1624                 goto err;
1625         }
1626
1627         down_write(&c->state_lock);
1628         mutex_lock(&c->sb_lock);
1629
1630         ret = bch2_sb_from_fs(c, ca);
1631         if (ret) {
1632                 bch_err(c, "device add error: new device superblock too small");
1633                 goto err_unlock;
1634         }
1635
1636         mi = bch2_sb_get_members(ca->disk_sb.sb);
1637
1638         if (!bch2_sb_resize_members(&ca->disk_sb,
1639                                 le32_to_cpu(mi->field.u64s) +
1640                                 sizeof(dev_mi) / sizeof(u64))) {
1641                 bch_err(c, "device add error: new device superblock too small");
1642                 ret = -BCH_ERR_ENOSPC_sb_members;
1643                 goto err_unlock;
1644         }
1645
1646         if (dynamic_fault("bcachefs:add:no_slot"))
1647                 goto no_slot;
1648
1649         mi = bch2_sb_get_members(c->disk_sb.sb);
1650         for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
1651                 if (!bch2_dev_exists(c->disk_sb.sb, mi, dev_idx))
1652                         goto have_slot;
1653 no_slot:
1654         bch_err(c, "device add error: already have maximum number of devices");
1655         ret = -BCH_ERR_ENOSPC_sb_members;
1656         goto err_unlock;
1657
1658 have_slot:
1659         nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
1660         u64s = (sizeof(struct bch_sb_field_members) +
1661                 sizeof(struct bch_member) * nr_devices) / sizeof(u64);
1662
1663         mi = bch2_sb_resize_members(&c->disk_sb, u64s);
1664         if (!mi) {
1665                 bch_err(c, "device add error: no room in superblock for member info");
1666                 ret = -BCH_ERR_ENOSPC_sb_members;
1667                 goto err_unlock;
1668         }
1669
1670         /* success: */
1671
1672         mi->members[dev_idx] = dev_mi;
1673         mi->members[dev_idx].last_mount = cpu_to_le64(ktime_get_real_seconds());
1674         c->disk_sb.sb->nr_devices       = nr_devices;
1675
1676         ca->disk_sb.sb->dev_idx = dev_idx;
1677         bch2_dev_attach(c, ca, dev_idx);
1678
1679         if (BCH_MEMBER_GROUP(&dev_mi)) {
1680                 ret = __bch2_dev_group_set(c, ca, label.buf);
1681                 if (ret) {
1682                         bch_err(c, "device add error: error setting label");
1683                         goto err_unlock;
1684                 }
1685         }
1686
1687         bch2_write_super(c);
1688         mutex_unlock(&c->sb_lock);
1689
1690         bch2_dev_usage_journal_reserve(c);
1691
1692         ret = bch2_trans_mark_dev_sb(c, ca);
1693         if (ret) {
1694                 bch_err(c, "device add error: error marking new superblock: %s", bch2_err_str(ret));
1695                 goto err_late;
1696         }
1697
1698         ret = bch2_fs_freespace_init(c);
1699         if (ret) {
1700                 bch_err(c, "device add error: error initializing free space: %s", bch2_err_str(ret));
1701                 goto err_late;
1702         }
1703
1704         ca->new_fs_bucket_idx = 0;
1705
1706         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1707                 __bch2_dev_read_write(c, ca);
1708
1709         up_write(&c->state_lock);
1710         return 0;
1711
1712 err_unlock:
1713         mutex_unlock(&c->sb_lock);
1714         up_write(&c->state_lock);
1715 err:
1716         if (ca)
1717                 bch2_dev_free(ca);
1718         bch2_free_super(&sb);
1719         printbuf_exit(&label);
1720         printbuf_exit(&errbuf);
1721         return ret;
1722 err_late:
1723         up_write(&c->state_lock);
1724         ca = NULL;
1725         goto err;
1726 }
1727
1728 /* Hot add existing device to running filesystem: */
1729 int bch2_dev_online(struct bch_fs *c, const char *path)
1730 {
1731         struct bch_opts opts = bch2_opts_empty();
1732         struct bch_sb_handle sb = { NULL };
1733         struct bch_sb_field_members *mi;
1734         struct bch_dev *ca;
1735         unsigned dev_idx;
1736         int ret;
1737
1738         down_write(&c->state_lock);
1739
1740         ret = bch2_read_super(path, &opts, &sb);
1741         if (ret) {
1742                 up_write(&c->state_lock);
1743                 return ret;
1744         }
1745
1746         dev_idx = sb.sb->dev_idx;
1747
1748         ret = bch2_dev_in_fs(c->disk_sb.sb, sb.sb);
1749         if (ret) {
1750                 bch_err(c, "error bringing %s online: %s", path, bch2_err_str(ret));
1751                 goto err;
1752         }
1753
1754         ret = bch2_dev_attach_bdev(c, &sb);
1755         if (ret)
1756                 goto err;
1757
1758         ca = bch_dev_locked(c, dev_idx);
1759
1760         ret = bch2_trans_mark_dev_sb(c, ca);
1761         if (ret) {
1762                 bch_err(c, "error bringing %s online: error from bch2_trans_mark_dev_sb: %s",
1763                         path, bch2_err_str(ret));
1764                 goto err;
1765         }
1766
1767         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1768                 __bch2_dev_read_write(c, ca);
1769
1770         mutex_lock(&c->sb_lock);
1771         mi = bch2_sb_get_members(c->disk_sb.sb);
1772
1773         mi->members[ca->dev_idx].last_mount =
1774                 cpu_to_le64(ktime_get_real_seconds());
1775
1776         bch2_write_super(c);
1777         mutex_unlock(&c->sb_lock);
1778
1779         ret = bch2_fs_freespace_init(c);
1780         if (ret)
1781                 bch_err(c, "device add error: error initializing free space: %s", bch2_err_str(ret));
1782
1783         up_write(&c->state_lock);
1784         return 0;
1785 err:
1786         up_write(&c->state_lock);
1787         bch2_free_super(&sb);
1788         return ret;
1789 }
1790
1791 int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
1792 {
1793         down_write(&c->state_lock);
1794
1795         if (!bch2_dev_is_online(ca)) {
1796                 bch_err(ca, "Already offline");
1797                 up_write(&c->state_lock);
1798                 return 0;
1799         }
1800
1801         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1802                 bch_err(ca, "Cannot offline required disk");
1803                 up_write(&c->state_lock);
1804                 return -BCH_ERR_device_state_not_allowed;
1805         }
1806
1807         __bch2_dev_offline(c, ca);
1808
1809         up_write(&c->state_lock);
1810         return 0;
1811 }
1812
1813 int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
1814 {
1815         struct bch_member *mi;
1816         int ret = 0;
1817
1818         down_write(&c->state_lock);
1819
1820         if (nbuckets < ca->mi.nbuckets) {
1821                 bch_err(ca, "Cannot shrink yet");
1822                 ret = -EINVAL;
1823                 goto err;
1824         }
1825
1826         if (bch2_dev_is_online(ca) &&
1827             get_capacity(ca->disk_sb.bdev->bd_disk) <
1828             ca->mi.bucket_size * nbuckets) {
1829                 bch_err(ca, "New size larger than device");
1830                 ret = -BCH_ERR_device_size_too_small;
1831                 goto err;
1832         }
1833
1834         ret = bch2_dev_buckets_resize(c, ca, nbuckets);
1835         if (ret) {
1836                 bch_err(ca, "Resize error: %s", bch2_err_str(ret));
1837                 goto err;
1838         }
1839
1840         ret = bch2_trans_mark_dev_sb(c, ca);
1841         if (ret)
1842                 goto err;
1843
1844         mutex_lock(&c->sb_lock);
1845         mi = &bch2_sb_get_members(c->disk_sb.sb)->members[ca->dev_idx];
1846         mi->nbuckets = cpu_to_le64(nbuckets);
1847
1848         bch2_write_super(c);
1849         mutex_unlock(&c->sb_lock);
1850
1851         bch2_recalc_capacity(c);
1852 err:
1853         up_write(&c->state_lock);
1854         return ret;
1855 }
1856
1857 /* return with ref on ca->ref: */
1858 struct bch_dev *bch2_dev_lookup(struct bch_fs *c, const char *name)
1859 {
1860         struct bch_dev *ca;
1861         unsigned i;
1862
1863         rcu_read_lock();
1864         for_each_member_device_rcu(ca, c, i, NULL)
1865                 if (!strcmp(name, ca->name))
1866                         goto found;
1867         ca = ERR_PTR(-BCH_ERR_ENOENT_dev_not_found);
1868 found:
1869         rcu_read_unlock();
1870
1871         return ca;
1872 }
1873
1874 /* Filesystem open: */
1875
1876 struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
1877                             struct bch_opts opts)
1878 {
1879         struct bch_sb_handle *sb = NULL;
1880         struct bch_fs *c = NULL;
1881         struct bch_sb_field_members *mi;
1882         unsigned i, best_sb = 0;
1883         struct printbuf errbuf = PRINTBUF;
1884         int ret = 0;
1885
1886         if (!try_module_get(THIS_MODULE))
1887                 return ERR_PTR(-ENODEV);
1888
1889         if (!nr_devices) {
1890                 ret = -EINVAL;
1891                 goto err;
1892         }
1893
1894         sb = kcalloc(nr_devices, sizeof(*sb), GFP_KERNEL);
1895         if (!sb) {
1896                 ret = -ENOMEM;
1897                 goto err;
1898         }
1899
1900         for (i = 0; i < nr_devices; i++) {
1901                 ret = bch2_read_super(devices[i], &opts, &sb[i]);
1902                 if (ret)
1903                         goto err;
1904
1905         }
1906
1907         for (i = 1; i < nr_devices; i++)
1908                 if (le64_to_cpu(sb[i].sb->seq) >
1909                     le64_to_cpu(sb[best_sb].sb->seq))
1910                         best_sb = i;
1911
1912         mi = bch2_sb_get_members(sb[best_sb].sb);
1913
1914         i = 0;
1915         while (i < nr_devices) {
1916                 if (i != best_sb &&
1917                     !bch2_dev_exists(sb[best_sb].sb, mi, sb[i].sb->dev_idx)) {
1918                         pr_info("%pg has been removed, skipping", sb[i].bdev);
1919                         bch2_free_super(&sb[i]);
1920                         array_remove_item(sb, nr_devices, i);
1921                         continue;
1922                 }
1923
1924                 ret = bch2_dev_in_fs(sb[best_sb].sb, sb[i].sb);
1925                 if (ret)
1926                         goto err_print;
1927                 i++;
1928         }
1929
1930         c = bch2_fs_alloc(sb[best_sb].sb, opts);
1931         if (IS_ERR(c)) {
1932                 ret = PTR_ERR(c);
1933                 goto err;
1934         }
1935
1936         down_write(&c->state_lock);
1937         for (i = 0; i < nr_devices; i++) {
1938                 ret = bch2_dev_attach_bdev(c, &sb[i]);
1939                 if (ret) {
1940                         up_write(&c->state_lock);
1941                         goto err;
1942                 }
1943         }
1944         up_write(&c->state_lock);
1945
1946         if (!bch2_fs_may_start(c)) {
1947                 ret = -BCH_ERR_insufficient_devices_to_start;
1948                 goto err_print;
1949         }
1950
1951         if (!c->opts.nostart) {
1952                 ret = bch2_fs_start(c);
1953                 if (ret)
1954                         goto err;
1955         }
1956 out:
1957         kfree(sb);
1958         printbuf_exit(&errbuf);
1959         module_put(THIS_MODULE);
1960         return c;
1961 err_print:
1962         pr_err("bch_fs_open err opening %s: %s",
1963                devices[0], bch2_err_str(ret));
1964 err:
1965         if (!IS_ERR_OR_NULL(c))
1966                 bch2_fs_stop(c);
1967         if (sb)
1968                 for (i = 0; i < nr_devices; i++)
1969                         bch2_free_super(&sb[i]);
1970         c = ERR_PTR(ret);
1971         goto out;
1972 }
1973
1974 /* Global interfaces/init */
1975
1976 static void bcachefs_exit(void)
1977 {
1978         bch2_debug_exit();
1979         bch2_vfs_exit();
1980         bch2_chardev_exit();
1981         bch2_btree_key_cache_exit();
1982         if (bcachefs_kset)
1983                 kset_unregister(bcachefs_kset);
1984 }
1985
1986 static int __init bcachefs_init(void)
1987 {
1988         bch2_bkey_pack_test();
1989
1990         if (!(bcachefs_kset = kset_create_and_add("bcachefs", NULL, fs_kobj)) ||
1991             bch2_btree_key_cache_init() ||
1992             bch2_chardev_init() ||
1993             bch2_vfs_init() ||
1994             bch2_debug_init())
1995                 goto err;
1996
1997         return 0;
1998 err:
1999         bcachefs_exit();
2000         return -ENOMEM;
2001 }
2002
2003 #define BCH_DEBUG_PARAM(name, description)                      \
2004         bool bch2_##name;                                       \
2005         module_param_named(name, bch2_##name, bool, 0644);      \
2006         MODULE_PARM_DESC(name, description);
2007 BCH_DEBUG_PARAMS()
2008 #undef BCH_DEBUG_PARAM
2009
2010 __maybe_unused
2011 static unsigned bch2_metadata_version = bcachefs_metadata_version_current;
2012 module_param_named(version, bch2_metadata_version, uint, 0400);
2013
2014 module_exit(bcachefs_exit);
2015 module_init(bcachefs_init);