fs/bcachefs/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 "debug.h"
  27 #include "disk_groups.h"
  28 #include "ec.h"
  29 #include "errcode.h"
  30 #include "error.h"
  31 #include "fs.h"
  32 #include "fs-io.h"
  33 #include "fs-io-buffered.h"
  34 #include "fs-io-direct.h"
  35 #include "fsck.h"
  36 #include "inode.h"
  37 #include "io_read.h"
  38 #include "io_write.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 "sb-counters.h"
  52 #include "sb-errors.h"
  53 #include "sb-members.h"
  54 #include "snapshot.h"
  55 #include "subvolume.h"
  56 #include "super.h"
  57 #include "super-io.h"
  58 #include "sysfs.h"
  59 #include "thread_with_file.h"
  60 #include "trace.h"
  61
  62 #include <linux/backing-dev.h>
  63 #include <linux/blkdev.h>
  64 #include <linux/debugfs.h>
  65 #include <linux/device.h>
  66 #include <linux/idr.h>
  67 #include <linux/module.h>
  68 #include <linux/percpu.h>
  69 #include <linux/random.h>
  70 #include <linux/sysfs.h>
  71 #include <crypto/hash.h>
  72
  73 MODULE_LICENSE("GPL");
  74 MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
  75 MODULE_DESCRIPTION("bcachefs filesystem");
  76 MODULE_SOFTDEP("pre: crc32c");
  77 MODULE_SOFTDEP("pre: crc64");
  78 MODULE_SOFTDEP("pre: sha256");
  79 MODULE_SOFTDEP("pre: chacha20");
  80 MODULE_SOFTDEP("pre: poly1305");
  81 MODULE_SOFTDEP("pre: xxhash");
  82
  83 const char * const bch2_fs_flag_strs[] = {
  84 #define x(n)            #n,
  85         BCH_FS_FLAGS()
  86 #undef x
  87         NULL
  88 };
  89
  90 __printf(2, 0)
  91 static void bch2_print_maybe_redirect(struct stdio_redirect *stdio, const char *fmt, va_list args)
  92 {
  93 #ifdef __KERNEL__
  94         if (unlikely(stdio)) {
  95                 if (fmt[0] == KERN_SOH[0])
  96                         fmt += 2;
  97
  98                 bch2_stdio_redirect_vprintf(stdio, true, fmt, args);
  99                 return;
 100         }
 101 #endif
 102         vprintk(fmt, args);
 103 }
 104
 105 void bch2_print_opts(struct bch_opts *opts, const char *fmt, ...)
 106 {
 107         struct stdio_redirect *stdio = (void *)(unsigned long)opts->stdio;
 108
 109         va_list args;
 110         va_start(args, fmt);
 111         bch2_print_maybe_redirect(stdio, fmt, args);
 112         va_end(args);
 113 }
 114
 115 void __bch2_print(struct bch_fs *c, const char *fmt, ...)
 116 {
 117         struct stdio_redirect *stdio = bch2_fs_stdio_redirect(c);
 118
 119         va_list args;
 120         va_start(args, fmt);
 121         bch2_print_maybe_redirect(stdio, fmt, args);
 122         va_end(args);
 123 }
 124
 125 #define KTYPE(type)                                                     \
 126 static const struct attribute_group type ## _group = {                  \
 127         .attrs = type ## _files                                         \
 128 };                                                                      \
 129                                                                         \
 130 static const struct attribute_group *type ## _groups[] = {              \
 131         &type ## _group,                                                \
 132         NULL                                                            \
 133 };                                                                      \
 134                                                                         \
 135 static const struct kobj_type type ## _ktype = {                        \
 136         .release        = type ## _release,                             \
 137         .sysfs_ops      = &type ## _sysfs_ops,                          \
 138         .default_groups = type ## _groups                               \
 139 }
 140
 141 static void bch2_fs_release(struct kobject *);
 142 static void bch2_dev_release(struct kobject *);
 143 static void bch2_fs_counters_release(struct kobject *k)
 144 {
 145 }
 146
 147 static void bch2_fs_internal_release(struct kobject *k)
 148 {
 149 }
 150
 151 static void bch2_fs_opts_dir_release(struct kobject *k)
 152 {
 153 }
 154
 155 static void bch2_fs_time_stats_release(struct kobject *k)
 156 {
 157 }
 158
 159 KTYPE(bch2_fs);
 160 KTYPE(bch2_fs_counters);
 161 KTYPE(bch2_fs_internal);
 162 KTYPE(bch2_fs_opts_dir);
 163 KTYPE(bch2_fs_time_stats);
 164 KTYPE(bch2_dev);
 165
 166 static struct kset *bcachefs_kset;
 167 static LIST_HEAD(bch_fs_list);
 168 static DEFINE_MUTEX(bch_fs_list_lock);
 169
 170 DECLARE_WAIT_QUEUE_HEAD(bch2_read_only_wait);
 171
 172 static void bch2_dev_free(struct bch_dev *);
 173 static int bch2_dev_alloc(struct bch_fs *, unsigned);
 174 static int bch2_dev_sysfs_online(struct bch_fs *, struct bch_dev *);
 175 static void __bch2_dev_read_only(struct bch_fs *, struct bch_dev *);
 176
 177 struct bch_fs *bch2_dev_to_fs(dev_t dev)
 178 {
 179         struct bch_fs *c;
 180
 181         mutex_lock(&bch_fs_list_lock);
 182         rcu_read_lock();
 183
 184         list_for_each_entry(c, &bch_fs_list, list)
 185                 for_each_member_device_rcu(c, ca, NULL)
 186                         if (ca->disk_sb.bdev && ca->disk_sb.bdev->bd_dev == dev) {
 187                                 closure_get(&c->cl);
 188                                 goto found;
 189                         }
 190         c = NULL;
 191 found:
 192         rcu_read_unlock();
 193         mutex_unlock(&bch_fs_list_lock);
 194
 195         return c;
 196 }
 197
 198 static struct bch_fs *__bch2_uuid_to_fs(__uuid_t uuid)
 199 {
 200         struct bch_fs *c;
 201
 202         lockdep_assert_held(&bch_fs_list_lock);
 203
 204         list_for_each_entry(c, &bch_fs_list, list)
 205                 if (!memcmp(&c->disk_sb.sb->uuid, &uuid, sizeof(uuid)))
 206                         return c;
 207
 208         return NULL;
 209 }
 210
 211 struct bch_fs *bch2_uuid_to_fs(__uuid_t uuid)
 212 {
 213         struct bch_fs *c;
 214
 215         mutex_lock(&bch_fs_list_lock);
 216         c = __bch2_uuid_to_fs(uuid);
 217         if (c)
 218                 closure_get(&c->cl);
 219         mutex_unlock(&bch_fs_list_lock);
 220
 221         return c;
 222 }
 223
 224 static void bch2_dev_usage_journal_reserve(struct bch_fs *c)
 225 {
 226         unsigned nr = 0, u64s =
 227                 ((sizeof(struct jset_entry_dev_usage) +
 228                   sizeof(struct jset_entry_dev_usage_type) * BCH_DATA_NR)) /
 229                 sizeof(u64);
 230
 231         rcu_read_lock();
 232         for_each_member_device_rcu(c, ca, NULL)
 233                 nr++;
 234         rcu_read_unlock();
 235
 236         bch2_journal_entry_res_resize(&c->journal,
 237                         &c->dev_usage_journal_res, u64s * nr);
 238 }
 239
 240 /* Filesystem RO/RW: */
 241
 242 /*
 243  * For startup/shutdown of RW stuff, the dependencies are:
 244  *
 245  * - foreground writes depend on copygc and rebalance (to free up space)
 246  *
 247  * - copygc and rebalance depend on mark and sweep gc (they actually probably
 248  *   don't because they either reserve ahead of time or don't block if
 249  *   allocations fail, but allocations can require mark and sweep gc to run
 250  *   because of generation number wraparound)
 251  *
 252  * - all of the above depends on the allocator threads
 253  *
 254  * - allocator depends on the journal (when it rewrites prios and gens)
 255  */
 256
 257 static void __bch2_fs_read_only(struct bch_fs *c)
 258 {
 259         unsigned clean_passes = 0;
 260         u64 seq = 0;
 261
 262         bch2_fs_ec_stop(c);
 263         bch2_open_buckets_stop(c, NULL, true);
 264         bch2_rebalance_stop(c);
 265         bch2_copygc_stop(c);
 266         bch2_gc_thread_stop(c);
 267         bch2_fs_ec_flush(c);
 268
 269         bch_verbose(c, "flushing journal and stopping allocators, journal seq %llu",
 270                     journal_cur_seq(&c->journal));
 271
 272         do {
 273                 clean_passes++;
 274
 275                 if (bch2_btree_interior_updates_flush(c) ||
 276                     bch2_journal_flush_all_pins(&c->journal) ||
 277                     bch2_btree_flush_all_writes(c) ||
 278                     seq != atomic64_read(&c->journal.seq)) {
 279                         seq = atomic64_read(&c->journal.seq);
 280                         clean_passes = 0;
 281                 }
 282         } while (clean_passes < 2);
 283
 284         bch_verbose(c, "flushing journal and stopping allocators complete, journal seq %llu",
 285                     journal_cur_seq(&c->journal));
 286
 287         if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
 288             !test_bit(BCH_FS_emergency_ro, &c->flags))
 289                 set_bit(BCH_FS_clean_shutdown, &c->flags);
 290         bch2_fs_journal_stop(&c->journal);
 291
 292         /*
 293          * After stopping journal:
 294          */
 295         for_each_member_device(c, ca)
 296                 bch2_dev_allocator_remove(c, ca);
 297 }
 298
 299 #ifndef BCH_WRITE_REF_DEBUG
 300 static void bch2_writes_disabled(struct percpu_ref *writes)
 301 {
 302         struct bch_fs *c = container_of(writes, struct bch_fs, writes);
 303
 304         set_bit(BCH_FS_write_disable_complete, &c->flags);
 305         wake_up(&bch2_read_only_wait);
 306 }
 307 #endif
 308
 309 void bch2_fs_read_only(struct bch_fs *c)
 310 {
 311         if (!test_bit(BCH_FS_rw, &c->flags)) {
 312                 bch2_journal_reclaim_stop(&c->journal);
 313                 return;
 314         }
 315
 316         BUG_ON(test_bit(BCH_FS_write_disable_complete, &c->flags));
 317
 318         bch_verbose(c, "going read-only");
 319
 320         /*
 321          * Block new foreground-end write operations from starting - any new
 322          * writes will return -EROFS:
 323          */
 324         set_bit(BCH_FS_going_ro, &c->flags);
 325 #ifndef BCH_WRITE_REF_DEBUG
 326         percpu_ref_kill(&c->writes);
 327 #else
 328         for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++)
 329                 bch2_write_ref_put(c, i);
 330 #endif
 331
 332         /*
 333          * If we're not doing an emergency shutdown, we want to wait on
 334          * outstanding writes to complete so they don't see spurious errors due
 335          * to shutting down the allocator:
 336          *
 337          * If we are doing an emergency shutdown outstanding writes may
 338          * hang until we shutdown the allocator so we don't want to wait
 339          * on outstanding writes before shutting everything down - but
 340          * we do need to wait on them before returning and signalling
 341          * that going RO is complete:
 342          */
 343         wait_event(bch2_read_only_wait,
 344                    test_bit(BCH_FS_write_disable_complete, &c->flags) ||
 345                    test_bit(BCH_FS_emergency_ro, &c->flags));
 346
 347         bool writes_disabled = test_bit(BCH_FS_write_disable_complete, &c->flags);
 348         if (writes_disabled)
 349                 bch_verbose(c, "finished waiting for writes to stop");
 350
 351         __bch2_fs_read_only(c);
 352
 353         wait_event(bch2_read_only_wait,
 354                    test_bit(BCH_FS_write_disable_complete, &c->flags));
 355
 356         if (!writes_disabled)
 357                 bch_verbose(c, "finished waiting for writes to stop");
 358
 359         clear_bit(BCH_FS_write_disable_complete, &c->flags);
 360         clear_bit(BCH_FS_going_ro, &c->flags);
 361         clear_bit(BCH_FS_rw, &c->flags);
 362
 363         if (!bch2_journal_error(&c->journal) &&
 364             !test_bit(BCH_FS_error, &c->flags) &&
 365             !test_bit(BCH_FS_emergency_ro, &c->flags) &&
 366             test_bit(BCH_FS_started, &c->flags) &&
 367             test_bit(BCH_FS_clean_shutdown, &c->flags) &&
 368             !c->opts.norecovery) {
 369                 BUG_ON(c->journal.last_empty_seq != journal_cur_seq(&c->journal));
 370                 BUG_ON(atomic_read(&c->btree_cache.dirty));
 371                 BUG_ON(atomic_long_read(&c->btree_key_cache.nr_dirty));
 372                 BUG_ON(c->btree_write_buffer.inc.keys.nr);
 373                 BUG_ON(c->btree_write_buffer.flushing.keys.nr);
 374
 375                 bch_verbose(c, "marking filesystem clean");
 376                 bch2_fs_mark_clean(c);
 377         } else {
 378                 bch_verbose(c, "done going read-only, filesystem not clean");
 379         }
 380 }
 381
 382 static void bch2_fs_read_only_work(struct work_struct *work)
 383 {
 384         struct bch_fs *c =
 385                 container_of(work, struct bch_fs, read_only_work);
 386
 387         down_write(&c->state_lock);
 388         bch2_fs_read_only(c);
 389         up_write(&c->state_lock);
 390 }
 391
 392 static void bch2_fs_read_only_async(struct bch_fs *c)
 393 {
 394         queue_work(system_long_wq, &c->read_only_work);
 395 }
 396
 397 bool bch2_fs_emergency_read_only(struct bch_fs *c)
 398 {
 399         bool ret = !test_and_set_bit(BCH_FS_emergency_ro, &c->flags);
 400
 401         bch2_journal_halt(&c->journal);
 402         bch2_fs_read_only_async(c);
 403
 404         wake_up(&bch2_read_only_wait);
 405         return ret;
 406 }
 407
 408 static int bch2_fs_read_write_late(struct bch_fs *c)
 409 {
 410         int ret;
 411
 412         /*
 413          * Data move operations can't run until after check_snapshots has
 414          * completed, and bch2_snapshot_is_ancestor() is available.
 415          *
 416          * Ideally we'd start copygc/rebalance earlier instead of waiting for
 417          * all of recovery/fsck to complete:
 418          */
 419         ret = bch2_copygc_start(c);
 420         if (ret) {
 421                 bch_err(c, "error starting copygc thread");
 422                 return ret;
 423         }
 424
 425         ret = bch2_rebalance_start(c);
 426         if (ret) {
 427                 bch_err(c, "error starting rebalance thread");
 428                 return ret;
 429         }
 430
 431         return 0;
 432 }
 433
 434 static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 435 {
 436         int ret;
 437
 438         if (test_bit(BCH_FS_initial_gc_unfixed, &c->flags)) {
 439                 bch_err(c, "cannot go rw, unfixed btree errors");
 440                 return -BCH_ERR_erofs_unfixed_errors;
 441         }
 442
 443         if (test_bit(BCH_FS_rw, &c->flags))
 444                 return 0;
 445
 446         bch_info(c, "going read-write");
 447
 448         ret = bch2_sb_members_v2_init(c);
 449         if (ret)
 450                 goto err;
 451
 452         ret = bch2_fs_mark_dirty(c);
 453         if (ret)
 454                 goto err;
 455
 456         clear_bit(BCH_FS_clean_shutdown, &c->flags);
 457
 458         /*
 459          * First journal write must be a flush write: after a clean shutdown we
 460          * don't read the journal, so the first journal write may end up
 461          * overwriting whatever was there previously, and there must always be
 462          * at least one non-flush write in the journal or recovery will fail:
 463          */
 464         set_bit(JOURNAL_NEED_FLUSH_WRITE, &c->journal.flags);
 465
 466         for_each_rw_member(c, ca)
 467                 bch2_dev_allocator_add(c, ca);
 468         bch2_recalc_capacity(c);
 469
 470         set_bit(BCH_FS_rw, &c->flags);
 471         set_bit(BCH_FS_was_rw, &c->flags);
 472
 473 #ifndef BCH_WRITE_REF_DEBUG
 474         percpu_ref_reinit(&c->writes);
 475 #else
 476         for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) {
 477                 BUG_ON(atomic_long_read(&c->writes[i]));
 478                 atomic_long_inc(&c->writes[i]);
 479         }
 480 #endif
 481
 482         ret = bch2_gc_thread_start(c);
 483         if (ret) {
 484                 bch_err(c, "error starting gc thread");
 485                 return ret;
 486         }
 487
 488         ret = bch2_journal_reclaim_start(&c->journal);
 489         if (ret)
 490                 goto err;
 491
 492         if (!early) {
 493                 ret = bch2_fs_read_write_late(c);
 494                 if (ret)
 495                         goto err;
 496         }
 497
 498         bch2_do_discards(c);
 499         bch2_do_invalidates(c);
 500         bch2_do_stripe_deletes(c);
 501         bch2_do_pending_node_rewrites(c);
 502         return 0;
 503 err:
 504         if (test_bit(BCH_FS_rw, &c->flags))
 505                 bch2_fs_read_only(c);
 506         else
 507                 __bch2_fs_read_only(c);
 508         return ret;
 509 }
 510
 511 int bch2_fs_read_write(struct bch_fs *c)
 512 {
 513         if (c->opts.norecovery)
 514                 return -BCH_ERR_erofs_norecovery;
 515
 516         if (c->opts.nochanges)
 517                 return -BCH_ERR_erofs_nochanges;
 518
 519         return __bch2_fs_read_write(c, false);
 520 }
 521
 522 int bch2_fs_read_write_early(struct bch_fs *c)
 523 {
 524         lockdep_assert_held(&c->state_lock);
 525
 526         return __bch2_fs_read_write(c, true);
 527 }
 528
 529 /* Filesystem startup/shutdown: */
 530
 531 static void __bch2_fs_free(struct bch_fs *c)
 532 {
 533         unsigned i;
 534
 535         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 536                 bch2_time_stats_exit(&c->times[i]);
 537
 538         bch2_free_pending_node_rewrites(c);
 539         bch2_fs_sb_errors_exit(c);
 540         bch2_fs_counters_exit(c);
 541         bch2_fs_snapshots_exit(c);
 542         bch2_fs_quota_exit(c);
 543         bch2_fs_fs_io_direct_exit(c);
 544         bch2_fs_fs_io_buffered_exit(c);
 545         bch2_fs_fsio_exit(c);
 546         bch2_fs_ec_exit(c);
 547         bch2_fs_encryption_exit(c);
 548         bch2_fs_nocow_locking_exit(c);
 549         bch2_fs_io_write_exit(c);
 550         bch2_fs_io_read_exit(c);
 551         bch2_fs_buckets_waiting_for_journal_exit(c);
 552         bch2_fs_btree_interior_update_exit(c);
 553         bch2_fs_btree_iter_exit(c);
 554         bch2_fs_btree_key_cache_exit(&c->btree_key_cache);
 555         bch2_fs_btree_cache_exit(c);
 556         bch2_fs_replicas_exit(c);
 557         bch2_fs_journal_exit(&c->journal);
 558         bch2_io_clock_exit(&c->io_clock[WRITE]);
 559         bch2_io_clock_exit(&c->io_clock[READ]);
 560         bch2_fs_compress_exit(c);
 561         bch2_journal_keys_put_initial(c);
 562         BUG_ON(atomic_read(&c->journal_keys.ref));
 563         bch2_fs_btree_write_buffer_exit(c);
 564         percpu_free_rwsem(&c->mark_lock);
 565         free_percpu(c->online_reserved);
 566
 567         darray_exit(&c->btree_roots_extra);
 568         free_percpu(c->pcpu);
 569         mempool_exit(&c->large_bkey_pool);
 570         mempool_exit(&c->btree_bounce_pool);
 571         bioset_exit(&c->btree_bio);
 572         mempool_exit(&c->fill_iter);
 573 #ifndef BCH_WRITE_REF_DEBUG
 574         percpu_ref_exit(&c->writes);
 575 #endif
 576         kfree(rcu_dereference_protected(c->disk_groups, 1));
 577         kfree(c->journal_seq_blacklist_table);
 578         kfree(c->unused_inode_hints);
 579
 580         if (c->write_ref_wq)
 581                 destroy_workqueue(c->write_ref_wq);
 582         if (c->io_complete_wq)
 583                 destroy_workqueue(c->io_complete_wq);
 584         if (c->copygc_wq)
 585                 destroy_workqueue(c->copygc_wq);
 586         if (c->btree_io_complete_wq)
 587                 destroy_workqueue(c->btree_io_complete_wq);
 588         if (c->btree_update_wq)
 589                 destroy_workqueue(c->btree_update_wq);
 590
 591         bch2_free_super(&c->disk_sb);
 592         kvfree(c);
 593         module_put(THIS_MODULE);
 594 }
 595
 596 static void bch2_fs_release(struct kobject *kobj)
 597 {
 598         struct bch_fs *c = container_of(kobj, struct bch_fs, kobj);
 599
 600         __bch2_fs_free(c);
 601 }
 602
 603 void __bch2_fs_stop(struct bch_fs *c)
 604 {
 605         bch_verbose(c, "shutting down");
 606
 607         set_bit(BCH_FS_stopping, &c->flags);
 608
 609         cancel_work_sync(&c->journal_seq_blacklist_gc_work);
 610
 611         down_write(&c->state_lock);
 612         bch2_fs_read_only(c);
 613         up_write(&c->state_lock);
 614
 615         for_each_member_device(c, ca)
 616                 if (ca->kobj.state_in_sysfs &&
 617                     ca->disk_sb.bdev)
 618                         sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
 619
 620         if (c->kobj.state_in_sysfs)
 621                 kobject_del(&c->kobj);
 622
 623         bch2_fs_debug_exit(c);
 624         bch2_fs_chardev_exit(c);
 625
 626         bch2_ro_ref_put(c);
 627         wait_event(c->ro_ref_wait, !refcount_read(&c->ro_ref));
 628
 629         kobject_put(&c->counters_kobj);
 630         kobject_put(&c->time_stats);
 631         kobject_put(&c->opts_dir);
 632         kobject_put(&c->internal);
 633
 634         /* btree prefetch might have kicked off reads in the background: */
 635         bch2_btree_flush_all_reads(c);
 636
 637         for_each_member_device(c, ca)
 638                 cancel_work_sync(&ca->io_error_work);
 639
 640         cancel_work_sync(&c->read_only_work);
 641 }
 642
 643 void bch2_fs_free(struct bch_fs *c)
 644 {
 645         unsigned i;
 646
 647         mutex_lock(&bch_fs_list_lock);
 648         list_del(&c->list);
 649         mutex_unlock(&bch_fs_list_lock);
 650
 651         closure_sync(&c->cl);
 652         closure_debug_destroy(&c->cl);
 653
 654         for (i = 0; i < c->sb.nr_devices; i++) {
 655                 struct bch_dev *ca = rcu_dereference_protected(c->devs[i], true);
 656
 657                 if (ca) {
 658                         bch2_free_super(&ca->disk_sb);
 659                         bch2_dev_free(ca);
 660                 }
 661         }
 662
 663         bch_verbose(c, "shutdown complete");
 664
 665         kobject_put(&c->kobj);
 666 }
 667
 668 void bch2_fs_stop(struct bch_fs *c)
 669 {
 670         __bch2_fs_stop(c);
 671         bch2_fs_free(c);
 672 }
 673
 674 static int bch2_fs_online(struct bch_fs *c)
 675 {
 676         int ret = 0;
 677
 678         lockdep_assert_held(&bch_fs_list_lock);
 679
 680         if (__bch2_uuid_to_fs(c->sb.uuid)) {
 681                 bch_err(c, "filesystem UUID already open");
 682                 return -EINVAL;
 683         }
 684
 685         ret = bch2_fs_chardev_init(c);
 686         if (ret) {
 687                 bch_err(c, "error creating character device");
 688                 return ret;
 689         }
 690
 691         bch2_fs_debug_init(c);
 692
 693         ret = kobject_add(&c->kobj, NULL, "%pU", c->sb.user_uuid.b) ?:
 694             kobject_add(&c->internal, &c->kobj, "internal") ?:
 695             kobject_add(&c->opts_dir, &c->kobj, "options") ?:
 696 #ifndef CONFIG_BCACHEFS_NO_LATENCY_ACCT
 697             kobject_add(&c->time_stats, &c->kobj, "time_stats") ?:
 698 #endif
 699             kobject_add(&c->counters_kobj, &c->kobj, "counters") ?:
 700             bch2_opts_create_sysfs_files(&c->opts_dir);
 701         if (ret) {
 702                 bch_err(c, "error creating sysfs objects");
 703                 return ret;
 704         }
 705
 706         down_write(&c->state_lock);
 707
 708         for_each_member_device(c, ca) {
 709                 ret = bch2_dev_sysfs_online(c, ca);
 710                 if (ret) {
 711                         bch_err(c, "error creating sysfs objects");
 712                         percpu_ref_put(&ca->ref);
 713                         goto err;
 714                 }
 715         }
 716
 717         BUG_ON(!list_empty(&c->list));
 718         list_add(&c->list, &bch_fs_list);
 719 err:
 720         up_write(&c->state_lock);
 721         return ret;
 722 }
 723
 724 static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 725 {
 726         struct bch_fs *c;
 727         struct printbuf name = PRINTBUF;
 728         unsigned i, iter_size;
 729         int ret = 0;
 730
 731         c = kvmalloc(sizeof(struct bch_fs), GFP_KERNEL|__GFP_ZERO);
 732         if (!c) {
 733                 c = ERR_PTR(-BCH_ERR_ENOMEM_fs_alloc);
 734                 goto out;
 735         }
 736
 737         c->stdio = (void *)(unsigned long) opts.stdio;
 738
 739         __module_get(THIS_MODULE);
 740
 741         closure_init(&c->cl, NULL);
 742
 743         c->kobj.kset = bcachefs_kset;
 744         kobject_init(&c->kobj, &bch2_fs_ktype);
 745         kobject_init(&c->internal, &bch2_fs_internal_ktype);
 746         kobject_init(&c->opts_dir, &bch2_fs_opts_dir_ktype);
 747         kobject_init(&c->time_stats, &bch2_fs_time_stats_ktype);
 748         kobject_init(&c->counters_kobj, &bch2_fs_counters_ktype);
 749
 750         c->minor                = -1;
 751         c->disk_sb.fs_sb        = true;
 752
 753         init_rwsem(&c->state_lock);
 754         mutex_init(&c->sb_lock);
 755         mutex_init(&c->replicas_gc_lock);
 756         mutex_init(&c->btree_root_lock);
 757         INIT_WORK(&c->read_only_work, bch2_fs_read_only_work);
 758
 759         refcount_set(&c->ro_ref, 1);
 760         init_waitqueue_head(&c->ro_ref_wait);
 761         sema_init(&c->online_fsck_mutex, 1);
 762
 763         init_rwsem(&c->gc_lock);
 764         mutex_init(&c->gc_gens_lock);
 765         atomic_set(&c->journal_keys.ref, 1);
 766         c->journal_keys.initial_ref_held = true;
 767
 768         for (i = 0; i < BCH_TIME_STAT_NR; i++)
 769                 bch2_time_stats_init(&c->times[i]);
 770
 771         bch2_fs_copygc_init(c);
 772         bch2_fs_btree_key_cache_init_early(&c->btree_key_cache);
 773         bch2_fs_btree_iter_init_early(c);
 774         bch2_fs_btree_interior_update_init_early(c);
 775         bch2_fs_allocator_background_init(c);
 776         bch2_fs_allocator_foreground_init(c);
 777         bch2_fs_rebalance_init(c);
 778         bch2_fs_quota_init(c);
 779         bch2_fs_ec_init_early(c);
 780         bch2_fs_move_init(c);
 781         bch2_fs_sb_errors_init_early(c);
 782
 783         INIT_LIST_HEAD(&c->list);
 784
 785         mutex_init(&c->usage_scratch_lock);
 786
 787         mutex_init(&c->bio_bounce_pages_lock);
 788         mutex_init(&c->snapshot_table_lock);
 789         init_rwsem(&c->snapshot_create_lock);
 790
 791         spin_lock_init(&c->btree_write_error_lock);
 792
 793         INIT_WORK(&c->journal_seq_blacklist_gc_work,
 794                   bch2_blacklist_entries_gc);
 795
 796         INIT_LIST_HEAD(&c->journal_iters);
 797
 798         INIT_LIST_HEAD(&c->fsck_error_msgs);
 799         mutex_init(&c->fsck_error_msgs_lock);
 800
 801         seqcount_init(&c->gc_pos_lock);
 802
 803         seqcount_init(&c->usage_lock);
 804
 805         sema_init(&c->io_in_flight, 128);
 806
 807         INIT_LIST_HEAD(&c->vfs_inodes_list);
 808         mutex_init(&c->vfs_inodes_lock);
 809
 810         c->copy_gc_enabled              = 1;
 811         c->rebalance.enabled            = 1;
 812         c->promote_whole_extents        = true;
 813
 814         c->journal.flush_write_time     = &c->times[BCH_TIME_journal_flush_write];
 815         c->journal.noflush_write_time   = &c->times[BCH_TIME_journal_noflush_write];
 816         c->journal.flush_seq_time       = &c->times[BCH_TIME_journal_flush_seq];
 817
 818         bch2_fs_btree_cache_init_early(&c->btree_cache);
 819
 820         mutex_init(&c->sectors_available_lock);
 821
 822         ret = percpu_init_rwsem(&c->mark_lock);
 823         if (ret)
 824                 goto err;
 825
 826         mutex_lock(&c->sb_lock);
 827         ret = bch2_sb_to_fs(c, sb);
 828         mutex_unlock(&c->sb_lock);
 829
 830         if (ret)
 831                 goto err;
 832
 833         pr_uuid(&name, c->sb.user_uuid.b);
 834         ret = name.allocation_failure ? -BCH_ERR_ENOMEM_fs_name_alloc : 0;
 835         if (ret)
 836                 goto err;
 837
 838         strscpy(c->name, name.buf, sizeof(c->name));
 839         printbuf_exit(&name);
 840
 841         /* Compat: */
 842         if (le16_to_cpu(sb->version) <= bcachefs_metadata_version_inode_v2 &&
 843             !BCH_SB_JOURNAL_FLUSH_DELAY(sb))
 844                 SET_BCH_SB_JOURNAL_FLUSH_DELAY(sb, 1000);
 845
 846         if (le16_to_cpu(sb->version) <= bcachefs_metadata_version_inode_v2 &&
 847             !BCH_SB_JOURNAL_RECLAIM_DELAY(sb))
 848                 SET_BCH_SB_JOURNAL_RECLAIM_DELAY(sb, 100);
 849
 850         c->opts = bch2_opts_default;
 851         ret = bch2_opts_from_sb(&c->opts, sb);
 852         if (ret)
 853                 goto err;
 854
 855         bch2_opts_apply(&c->opts, opts);
 856
 857         c->btree_key_cache_btrees |= 1U << BTREE_ID_alloc;
 858         if (c->opts.inodes_use_key_cache)
 859                 c->btree_key_cache_btrees |= 1U << BTREE_ID_inodes;
 860         c->btree_key_cache_btrees |= 1U << BTREE_ID_logged_ops;
 861
 862         c->block_bits           = ilog2(block_sectors(c));
 863         c->btree_foreground_merge_threshold = BTREE_FOREGROUND_MERGE_THRESHOLD(c);
 864
 865         if (bch2_fs_init_fault("fs_alloc")) {
 866                 bch_err(c, "fs_alloc fault injected");
 867                 ret = -EFAULT;
 868                 goto err;
 869         }
 870
 871         iter_size = sizeof(struct sort_iter) +
 872                 (btree_blocks(c) + 1) * 2 *
 873                 sizeof(struct sort_iter_set);
 874
 875         c->inode_shard_bits = ilog2(roundup_pow_of_two(num_possible_cpus()));
 876
 877         if (!(c->btree_update_wq = alloc_workqueue("bcachefs",
 878                                 WQ_HIGHPRI|WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_UNBOUND, 512)) ||
 879             !(c->btree_io_complete_wq = alloc_workqueue("bcachefs_btree_io",
 880                                 WQ_HIGHPRI|WQ_FREEZABLE|WQ_MEM_RECLAIM, 1)) ||
 881             !(c->copygc_wq = alloc_workqueue("bcachefs_copygc",
 882                                 WQ_HIGHPRI|WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
 883             !(c->io_complete_wq = alloc_workqueue("bcachefs_io",
 884                                 WQ_HIGHPRI|WQ_FREEZABLE|WQ_MEM_RECLAIM, 512)) ||
 885             !(c->write_ref_wq = alloc_workqueue("bcachefs_write_ref",
 886                                 WQ_FREEZABLE, 0)) ||
 887 #ifndef BCH_WRITE_REF_DEBUG
 888             percpu_ref_init(&c->writes, bch2_writes_disabled,
 889                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
 890 #endif
 891             mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
 892             bioset_init(&c->btree_bio, 1,
 893                         max(offsetof(struct btree_read_bio, bio),
 894                             offsetof(struct btree_write_bio, wbio.bio)),
 895                         BIOSET_NEED_BVECS) ||
 896             !(c->pcpu = alloc_percpu(struct bch_fs_pcpu)) ||
 897             !(c->online_reserved = alloc_percpu(u64)) ||
 898             mempool_init_kvmalloc_pool(&c->btree_bounce_pool, 1,
 899                                        c->opts.btree_node_size) ||
 900             mempool_init_kmalloc_pool(&c->large_bkey_pool, 1, 2048) ||
 901             !(c->unused_inode_hints = kcalloc(1U << c->inode_shard_bits,
 902                                               sizeof(u64), GFP_KERNEL))) {
 903                 ret = -BCH_ERR_ENOMEM_fs_other_alloc;
 904                 goto err;
 905         }
 906
 907         ret = bch2_fs_counters_init(c) ?:
 908             bch2_fs_sb_errors_init(c) ?:
 909             bch2_io_clock_init(&c->io_clock[READ]) ?:
 910             bch2_io_clock_init(&c->io_clock[WRITE]) ?:
 911             bch2_fs_journal_init(&c->journal) ?:
 912             bch2_fs_replicas_init(c) ?:
 913             bch2_fs_btree_cache_init(c) ?:
 914             bch2_fs_btree_key_cache_init(&c->btree_key_cache) ?:
 915             bch2_fs_btree_iter_init(c) ?:
 916             bch2_fs_btree_interior_update_init(c) ?:
 917             bch2_fs_buckets_waiting_for_journal_init(c) ?:
 918             bch2_fs_btree_write_buffer_init(c) ?:
 919             bch2_fs_subvolumes_init(c) ?:
 920             bch2_fs_io_read_init(c) ?:
 921             bch2_fs_io_write_init(c) ?:
 922             bch2_fs_nocow_locking_init(c) ?:
 923             bch2_fs_encryption_init(c) ?:
 924             bch2_fs_compress_init(c) ?:
 925             bch2_fs_ec_init(c) ?:
 926             bch2_fs_fsio_init(c) ?:
 927             bch2_fs_fs_io_buffered_init(c) ?:
 928             bch2_fs_fs_io_direct_init(c);
 929         if (ret)
 930                 goto err;
 931
 932         for (i = 0; i < c->sb.nr_devices; i++)
 933                 if (bch2_dev_exists(c->disk_sb.sb, i) &&
 934                     bch2_dev_alloc(c, i)) {
 935                         ret = -EEXIST;
 936                         goto err;
 937                 }
 938
 939         bch2_journal_entry_res_resize(&c->journal,
 940                         &c->btree_root_journal_res,
 941                         BTREE_ID_NR * (JSET_KEYS_U64s + BKEY_BTREE_PTR_U64s_MAX));
 942         bch2_dev_usage_journal_reserve(c);
 943         bch2_journal_entry_res_resize(&c->journal,
 944                         &c->clock_journal_res,
 945                         (sizeof(struct jset_entry_clock) / sizeof(u64)) * 2);
 946
 947         mutex_lock(&bch_fs_list_lock);
 948         ret = bch2_fs_online(c);
 949         mutex_unlock(&bch_fs_list_lock);
 950
 951         if (ret)
 952                 goto err;
 953 out:
 954         return c;
 955 err:
 956         bch2_fs_free(c);
 957         c = ERR_PTR(ret);
 958         goto out;
 959 }
 960
 961 noinline_for_stack
 962 static void print_mount_opts(struct bch_fs *c)
 963 {
 964         enum bch_opt_id i;
 965         struct printbuf p = PRINTBUF;
 966         bool first = true;
 967
 968         prt_str(&p, "mounting version ");
 969         bch2_version_to_text(&p, c->sb.version);
 970
 971         if (c->opts.read_only) {
 972                 prt_str(&p, " opts=");
 973                 first = false;
 974                 prt_printf(&p, "ro");
 975         }
 976
 977         for (i = 0; i < bch2_opts_nr; i++) {
 978                 const struct bch_option *opt = &bch2_opt_table[i];
 979                 u64 v = bch2_opt_get_by_id(&c->opts, i);
 980
 981                 if (!(opt->flags & OPT_MOUNT))
 982                         continue;
 983
 984                 if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
 985                         continue;
 986
 987                 prt_str(&p, first ? " opts=" : ",");
 988                 first = false;
 989                 bch2_opt_to_text(&p, c, c->disk_sb.sb, opt, v, OPT_SHOW_MOUNT_STYLE);
 990         }
 991
 992         bch_info(c, "%s", p.buf);
 993         printbuf_exit(&p);
 994 }
 995
 996 int bch2_fs_start(struct bch_fs *c)
 997 {
 998         time64_t now = ktime_get_real_seconds();
 999         int ret;
1000
1001         print_mount_opts(c);
1002
1003         down_write(&c->state_lock);
1004
1005         BUG_ON(test_bit(BCH_FS_started, &c->flags));
1006
1007         mutex_lock(&c->sb_lock);
1008
1009         ret = bch2_sb_members_v2_init(c);
1010         if (ret) {
1011                 mutex_unlock(&c->sb_lock);
1012                 goto err;
1013         }
1014
1015         for_each_online_member(c, ca)
1016                 bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx)->last_mount = cpu_to_le64(now);
1017
1018         mutex_unlock(&c->sb_lock);
1019
1020         for_each_rw_member(c, ca)
1021                 bch2_dev_allocator_add(c, ca);
1022         bch2_recalc_capacity(c);
1023
1024         ret = BCH_SB_INITIALIZED(c->disk_sb.sb)
1025                 ? bch2_fs_recovery(c)
1026                 : bch2_fs_initialize(c);
1027         if (ret)
1028                 goto err;
1029
1030         ret = bch2_opts_check_may_set(c);
1031         if (ret)
1032                 goto err;
1033
1034         if (bch2_fs_init_fault("fs_start")) {
1035                 bch_err(c, "fs_start fault injected");
1036                 ret = -EINVAL;
1037                 goto err;
1038         }
1039
1040         set_bit(BCH_FS_started, &c->flags);
1041
1042         if (c->opts.read_only) {
1043                 bch2_fs_read_only(c);
1044         } else {
1045                 ret = !test_bit(BCH_FS_rw, &c->flags)
1046                         ? bch2_fs_read_write(c)
1047                         : bch2_fs_read_write_late(c);
1048                 if (ret)
1049                         goto err;
1050         }
1051
1052         ret = 0;
1053 err:
1054         if (ret)
1055                 bch_err_msg(c, ret, "starting filesystem");
1056         else
1057                 bch_verbose(c, "done starting filesystem");
1058         up_write(&c->state_lock);
1059         return ret;
1060 }
1061
1062 static int bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
1063 {
1064         struct bch_member m = bch2_sb_member_get(sb, sb->dev_idx);
1065
1066         if (le16_to_cpu(sb->block_size) != block_sectors(c))
1067                 return -BCH_ERR_mismatched_block_size;
1068
1069         if (le16_to_cpu(m.bucket_size) <
1070             BCH_SB_BTREE_NODE_SIZE(c->disk_sb.sb))
1071                 return -BCH_ERR_bucket_size_too_small;
1072
1073         return 0;
1074 }
1075
1076 static int bch2_dev_in_fs(struct bch_sb_handle *fs,
1077                           struct bch_sb_handle *sb,
1078                           struct bch_opts *opts)
1079 {
1080         if (fs == sb)
1081                 return 0;
1082
1083         if (!uuid_equal(&fs->sb->uuid, &sb->sb->uuid))
1084                 return -BCH_ERR_device_not_a_member_of_filesystem;
1085
1086         if (!bch2_dev_exists(fs->sb, sb->sb->dev_idx))
1087                 return -BCH_ERR_device_has_been_removed;
1088
1089         if (fs->sb->block_size != sb->sb->block_size)
1090                 return -BCH_ERR_mismatched_block_size;
1091
1092         if (le16_to_cpu(fs->sb->version) < bcachefs_metadata_version_member_seq ||
1093             le16_to_cpu(sb->sb->version) < bcachefs_metadata_version_member_seq)
1094                 return 0;
1095
1096         if (fs->sb->seq == sb->sb->seq &&
1097             fs->sb->write_time != sb->sb->write_time) {
1098                 struct printbuf buf = PRINTBUF;
1099
1100                 prt_str(&buf, "Split brain detected between ");
1101                 prt_bdevname(&buf, sb->bdev);
1102                 prt_str(&buf, " and ");
1103                 prt_bdevname(&buf, fs->bdev);
1104                 prt_char(&buf, ':');
1105                 prt_newline(&buf);
1106                 prt_printf(&buf, "seq=%llu but write_time different, got", le64_to_cpu(sb->sb->seq));
1107                 prt_newline(&buf);
1108
1109                 prt_bdevname(&buf, fs->bdev);
1110                 prt_char(&buf, ' ');
1111                 bch2_prt_datetime(&buf, le64_to_cpu(fs->sb->write_time));;
1112                 prt_newline(&buf);
1113
1114                 prt_bdevname(&buf, sb->bdev);
1115                 prt_char(&buf, ' ');
1116                 bch2_prt_datetime(&buf, le64_to_cpu(sb->sb->write_time));;
1117                 prt_newline(&buf);
1118
1119                 if (!opts->no_splitbrain_check)
1120                         prt_printf(&buf, "Not using older sb");
1121
1122                 pr_err("%s", buf.buf);
1123                 printbuf_exit(&buf);
1124
1125                 if (!opts->no_splitbrain_check)
1126                         return -BCH_ERR_device_splitbrain;
1127         }
1128
1129         struct bch_member m = bch2_sb_member_get(fs->sb, sb->sb->dev_idx);
1130         u64 seq_from_fs         = le64_to_cpu(m.seq);
1131         u64 seq_from_member     = le64_to_cpu(sb->sb->seq);
1132
1133         if (seq_from_fs && seq_from_fs < seq_from_member) {
1134                 struct printbuf buf = PRINTBUF;
1135
1136                 prt_str(&buf, "Split brain detected between ");
1137                 prt_bdevname(&buf, sb->bdev);
1138                 prt_str(&buf, " and ");
1139                 prt_bdevname(&buf, fs->bdev);
1140                 prt_char(&buf, ':');
1141                 prt_newline(&buf);
1142
1143                 prt_bdevname(&buf, fs->bdev);
1144                 prt_str(&buf, " believes seq of ");
1145                 prt_bdevname(&buf, sb->bdev);
1146                 prt_printf(&buf, " to be %llu, but ", seq_from_fs);
1147                 prt_bdevname(&buf, sb->bdev);
1148                 prt_printf(&buf, " has %llu\n", seq_from_member);
1149
1150                 if (!opts->no_splitbrain_check) {
1151                         prt_str(&buf, "Not using ");
1152                         prt_bdevname(&buf, sb->bdev);
1153                 }
1154
1155                 pr_err("%s", buf.buf);
1156                 printbuf_exit(&buf);
1157
1158                 if (!opts->no_splitbrain_check)
1159                         return -BCH_ERR_device_splitbrain;
1160         }
1161
1162         return 0;
1163 }
1164
1165 /* Device startup/shutdown: */
1166
1167 static void bch2_dev_release(struct kobject *kobj)
1168 {
1169         struct bch_dev *ca = container_of(kobj, struct bch_dev, kobj);
1170
1171         kfree(ca);
1172 }
1173
1174 static void bch2_dev_free(struct bch_dev *ca)
1175 {
1176         cancel_work_sync(&ca->io_error_work);
1177
1178         if (ca->kobj.state_in_sysfs &&
1179             ca->disk_sb.bdev)
1180                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1181
1182         if (ca->kobj.state_in_sysfs)
1183                 kobject_del(&ca->kobj);
1184
1185         bch2_free_super(&ca->disk_sb);
1186         bch2_dev_journal_exit(ca);
1187
1188         free_percpu(ca->io_done);
1189         bioset_exit(&ca->replica_set);
1190         bch2_dev_buckets_free(ca);
1191         free_page((unsigned long) ca->sb_read_scratch);
1192
1193         bch2_time_stats_quantiles_exit(&ca->io_latency[WRITE]);
1194         bch2_time_stats_quantiles_exit(&ca->io_latency[READ]);
1195
1196         percpu_ref_exit(&ca->io_ref);
1197         percpu_ref_exit(&ca->ref);
1198         kobject_put(&ca->kobj);
1199 }
1200
1201 static void __bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca)
1202 {
1203
1204         lockdep_assert_held(&c->state_lock);
1205
1206         if (percpu_ref_is_zero(&ca->io_ref))
1207                 return;
1208
1209         __bch2_dev_read_only(c, ca);
1210
1211         reinit_completion(&ca->io_ref_completion);
1212         percpu_ref_kill(&ca->io_ref);
1213         wait_for_completion(&ca->io_ref_completion);
1214
1215         if (ca->kobj.state_in_sysfs) {
1216                 sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1217                 sysfs_remove_link(&ca->kobj, "block");
1218         }
1219
1220         bch2_free_super(&ca->disk_sb);
1221         bch2_dev_journal_exit(ca);
1222 }
1223
1224 static void bch2_dev_ref_complete(struct percpu_ref *ref)
1225 {
1226         struct bch_dev *ca = container_of(ref, struct bch_dev, ref);
1227
1228         complete(&ca->ref_completion);
1229 }
1230
1231 static void bch2_dev_io_ref_complete(struct percpu_ref *ref)
1232 {
1233         struct bch_dev *ca = container_of(ref, struct bch_dev, io_ref);
1234
1235         complete(&ca->io_ref_completion);
1236 }
1237
1238 static int bch2_dev_sysfs_online(struct bch_fs *c, struct bch_dev *ca)
1239 {
1240         int ret;
1241
1242         if (!c->kobj.state_in_sysfs)
1243                 return 0;
1244
1245         if (!ca->kobj.state_in_sysfs) {
1246                 ret = kobject_add(&ca->kobj, &c->kobj,
1247                                   "dev-%u", ca->dev_idx);
1248                 if (ret)
1249                         return ret;
1250         }
1251
1252         if (ca->disk_sb.bdev) {
1253                 struct kobject *block = bdev_kobj(ca->disk_sb.bdev);
1254
1255                 ret = sysfs_create_link(block, &ca->kobj, "bcachefs");
1256                 if (ret)
1257                         return ret;
1258
1259                 ret = sysfs_create_link(&ca->kobj, block, "block");
1260                 if (ret)
1261                         return ret;
1262         }
1263
1264         return 0;
1265 }
1266
1267 static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
1268                                         struct bch_member *member)
1269 {
1270         struct bch_dev *ca;
1271         unsigned i;
1272
1273         ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1274         if (!ca)
1275                 return NULL;
1276
1277         kobject_init(&ca->kobj, &bch2_dev_ktype);
1278         init_completion(&ca->ref_completion);
1279         init_completion(&ca->io_ref_completion);
1280
1281         init_rwsem(&ca->bucket_lock);
1282
1283         INIT_WORK(&ca->io_error_work, bch2_io_error_work);
1284
1285         bch2_time_stats_quantiles_init(&ca->io_latency[READ]);
1286         bch2_time_stats_quantiles_init(&ca->io_latency[WRITE]);
1287
1288         ca->mi = bch2_mi_to_cpu(member);
1289
1290         for (i = 0; i < ARRAY_SIZE(member->errors); i++)
1291                 atomic64_set(&ca->errors[i], le64_to_cpu(member->errors[i]));
1292
1293         ca->uuid = member->uuid;
1294
1295         ca->nr_btree_reserve = DIV_ROUND_UP(BTREE_NODE_RESERVE,
1296                              ca->mi.bucket_size / btree_sectors(c));
1297
1298         if (percpu_ref_init(&ca->ref, bch2_dev_ref_complete,
1299                             0, GFP_KERNEL) ||
1300             percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
1301                             PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
1302             !(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
1303             bch2_dev_buckets_alloc(c, ca) ||
1304             bioset_init(&ca->replica_set, 4,
1305                         offsetof(struct bch_write_bio, bio), 0) ||
1306             !(ca->io_done       = alloc_percpu(*ca->io_done)))
1307                 goto err;
1308
1309         return ca;
1310 err:
1311         bch2_dev_free(ca);
1312         return NULL;
1313 }
1314
1315 static void bch2_dev_attach(struct bch_fs *c, struct bch_dev *ca,
1316                             unsigned dev_idx)
1317 {
1318         ca->dev_idx = dev_idx;
1319         __set_bit(ca->dev_idx, ca->self.d);
1320         scnprintf(ca->name, sizeof(ca->name), "dev-%u", dev_idx);
1321
1322         ca->fs = c;
1323         rcu_assign_pointer(c->devs[ca->dev_idx], ca);
1324
1325         if (bch2_dev_sysfs_online(c, ca))
1326                 pr_warn("error creating sysfs objects");
1327 }
1328
1329 static int bch2_dev_alloc(struct bch_fs *c, unsigned dev_idx)
1330 {
1331         struct bch_member member = bch2_sb_member_get(c->disk_sb.sb, dev_idx);
1332         struct bch_dev *ca = NULL;
1333         int ret = 0;
1334
1335         if (bch2_fs_init_fault("dev_alloc"))
1336                 goto err;
1337
1338         ca = __bch2_dev_alloc(c, &member);
1339         if (!ca)
1340                 goto err;
1341
1342         ca->fs = c;
1343
1344         bch2_dev_attach(c, ca, dev_idx);
1345         return ret;
1346 err:
1347         if (ca)
1348                 bch2_dev_free(ca);
1349         return -BCH_ERR_ENOMEM_dev_alloc;
1350 }
1351
1352 static int __bch2_dev_attach_bdev(struct bch_dev *ca, struct bch_sb_handle *sb)
1353 {
1354         unsigned ret;
1355
1356         if (bch2_dev_is_online(ca)) {
1357                 bch_err(ca, "already have device online in slot %u",
1358                         sb->sb->dev_idx);
1359                 return -BCH_ERR_device_already_online;
1360         }
1361
1362         if (get_capacity(sb->bdev->bd_disk) <
1363             ca->mi.bucket_size * ca->mi.nbuckets) {
1364                 bch_err(ca, "cannot online: device too small");
1365                 return -BCH_ERR_device_size_too_small;
1366         }
1367
1368         BUG_ON(!percpu_ref_is_zero(&ca->io_ref));
1369
1370         ret = bch2_dev_journal_init(ca, sb->sb);
1371         if (ret)
1372                 return ret;
1373
1374         /* Commit: */
1375         ca->disk_sb = *sb;
1376         memset(sb, 0, sizeof(*sb));
1377
1378         ca->dev = ca->disk_sb.bdev->bd_dev;
1379
1380         percpu_ref_reinit(&ca->io_ref);
1381
1382         return 0;
1383 }
1384
1385 static int bch2_dev_attach_bdev(struct bch_fs *c, struct bch_sb_handle *sb)
1386 {
1387         struct bch_dev *ca;
1388         int ret;
1389
1390         lockdep_assert_held(&c->state_lock);
1391
1392         if (le64_to_cpu(sb->sb->seq) >
1393             le64_to_cpu(c->disk_sb.sb->seq))
1394                 bch2_sb_to_fs(c, sb->sb);
1395
1396         BUG_ON(sb->sb->dev_idx >= c->sb.nr_devices ||
1397                !c->devs[sb->sb->dev_idx]);
1398
1399         ca = bch_dev_locked(c, sb->sb->dev_idx);
1400
1401         ret = __bch2_dev_attach_bdev(ca, sb);
1402         if (ret)
1403                 return ret;
1404
1405         bch2_dev_sysfs_online(c, ca);
1406
1407         struct printbuf name = PRINTBUF;
1408         prt_bdevname(&name, ca->disk_sb.bdev);
1409
1410         if (c->sb.nr_devices == 1)
1411                 strscpy(c->name, name.buf, sizeof(c->name));
1412         strscpy(ca->name, name.buf, sizeof(ca->name));
1413
1414         printbuf_exit(&name);
1415
1416         rebalance_wakeup(c);
1417         return 0;
1418 }
1419
1420 /* Device management: */
1421
1422 /*
1423  * Note: this function is also used by the error paths - when a particular
1424  * device sees an error, we call it to determine whether we can just set the
1425  * device RO, or - if this function returns false - we'll set the whole
1426  * filesystem RO:
1427  *
1428  * XXX: maybe we should be more explicit about whether we're changing state
1429  * because we got an error or what have you?
1430  */
1431 bool bch2_dev_state_allowed(struct bch_fs *c, struct bch_dev *ca,
1432                             enum bch_member_state new_state, int flags)
1433 {
1434         struct bch_devs_mask new_online_devs;
1435         int nr_rw = 0, required;
1436
1437         lockdep_assert_held(&c->state_lock);
1438
1439         switch (new_state) {
1440         case BCH_MEMBER_STATE_rw:
1441                 return true;
1442         case BCH_MEMBER_STATE_ro:
1443                 if (ca->mi.state != BCH_MEMBER_STATE_rw)
1444                         return true;
1445
1446                 /* do we have enough devices to write to?  */
1447                 for_each_member_device(c, ca2)
1448                         if (ca2 != ca)
1449                                 nr_rw += ca2->mi.state == BCH_MEMBER_STATE_rw;
1450
1451                 required = max(!(flags & BCH_FORCE_IF_METADATA_DEGRADED)
1452                                ? c->opts.metadata_replicas
1453                                : metadata_replicas_required(c),
1454                                !(flags & BCH_FORCE_IF_DATA_DEGRADED)
1455                                ? c->opts.data_replicas
1456                                : data_replicas_required(c));
1457
1458                 return nr_rw >= required;
1459         case BCH_MEMBER_STATE_failed:
1460         case BCH_MEMBER_STATE_spare:
1461                 if (ca->mi.state != BCH_MEMBER_STATE_rw &&
1462                     ca->mi.state != BCH_MEMBER_STATE_ro)
1463                         return true;
1464
1465                 /* do we have enough devices to read from?  */
1466                 new_online_devs = bch2_online_devs(c);
1467                 __clear_bit(ca->dev_idx, new_online_devs.d);
1468
1469                 return bch2_have_enough_devs(c, new_online_devs, flags, false);
1470         default:
1471                 BUG();
1472         }
1473 }
1474
1475 static bool bch2_fs_may_start(struct bch_fs *c)
1476 {
1477         struct bch_dev *ca;
1478         unsigned i, flags = 0;
1479
1480         if (c->opts.very_degraded)
1481                 flags |= BCH_FORCE_IF_DEGRADED|BCH_FORCE_IF_LOST;
1482
1483         if (c->opts.degraded)
1484                 flags |= BCH_FORCE_IF_DEGRADED;
1485
1486         if (!c->opts.degraded &&
1487             !c->opts.very_degraded) {
1488                 mutex_lock(&c->sb_lock);
1489
1490                 for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
1491                         if (!bch2_dev_exists(c->disk_sb.sb, i))
1492                                 continue;
1493
1494                         ca = bch_dev_locked(c, i);
1495
1496                         if (!bch2_dev_is_online(ca) &&
1497                             (ca->mi.state == BCH_MEMBER_STATE_rw ||
1498                              ca->mi.state == BCH_MEMBER_STATE_ro)) {
1499                                 mutex_unlock(&c->sb_lock);
1500                                 return false;
1501                         }
1502                 }
1503                 mutex_unlock(&c->sb_lock);
1504         }
1505
1506         return bch2_have_enough_devs(c, bch2_online_devs(c), flags, true);
1507 }
1508
1509 static void __bch2_dev_read_only(struct bch_fs *c, struct bch_dev *ca)
1510 {
1511         /*
1512          * The allocator thread itself allocates btree nodes, so stop it first:
1513          */
1514         bch2_dev_allocator_remove(c, ca);
1515         bch2_dev_journal_stop(&c->journal, ca);
1516 }
1517
1518 static void __bch2_dev_read_write(struct bch_fs *c, struct bch_dev *ca)
1519 {
1520         lockdep_assert_held(&c->state_lock);
1521
1522         BUG_ON(ca->mi.state != BCH_MEMBER_STATE_rw);
1523
1524         bch2_dev_allocator_add(c, ca);
1525         bch2_recalc_capacity(c);
1526 }
1527
1528 int __bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1529                          enum bch_member_state new_state, int flags)
1530 {
1531         struct bch_member *m;
1532         int ret = 0;
1533
1534         if (ca->mi.state == new_state)
1535                 return 0;
1536
1537         if (!bch2_dev_state_allowed(c, ca, new_state, flags))
1538                 return -BCH_ERR_device_state_not_allowed;
1539
1540         if (new_state != BCH_MEMBER_STATE_rw)
1541                 __bch2_dev_read_only(c, ca);
1542
1543         bch_notice(ca, "%s", bch2_member_states[new_state]);
1544
1545         mutex_lock(&c->sb_lock);
1546         m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
1547         SET_BCH_MEMBER_STATE(m, new_state);
1548         bch2_write_super(c);
1549         mutex_unlock(&c->sb_lock);
1550
1551         if (new_state == BCH_MEMBER_STATE_rw)
1552                 __bch2_dev_read_write(c, ca);
1553
1554         rebalance_wakeup(c);
1555
1556         return ret;
1557 }
1558
1559 int bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1560                        enum bch_member_state new_state, int flags)
1561 {
1562         int ret;
1563
1564         down_write(&c->state_lock);
1565         ret = __bch2_dev_set_state(c, ca, new_state, flags);
1566         up_write(&c->state_lock);
1567
1568         return ret;
1569 }
1570
1571 /* Device add/removal: */
1572
1573 static int bch2_dev_remove_alloc(struct bch_fs *c, struct bch_dev *ca)
1574 {
1575         struct bpos start       = POS(ca->dev_idx, 0);
1576         struct bpos end         = POS(ca->dev_idx, U64_MAX);
1577         int ret;
1578
1579         /*
1580          * We clear the LRU and need_discard btrees first so that we don't race
1581          * with bch2_do_invalidates() and bch2_do_discards()
1582          */
1583         ret =   bch2_btree_delete_range(c, BTREE_ID_lru, start, end,
1584                                         BTREE_TRIGGER_NORUN, NULL) ?:
1585                 bch2_btree_delete_range(c, BTREE_ID_need_discard, start, end,
1586                                         BTREE_TRIGGER_NORUN, NULL) ?:
1587                 bch2_btree_delete_range(c, BTREE_ID_freespace, start, end,
1588                                         BTREE_TRIGGER_NORUN, NULL) ?:
1589                 bch2_btree_delete_range(c, BTREE_ID_backpointers, start, end,
1590                                         BTREE_TRIGGER_NORUN, NULL) ?:
1591                 bch2_btree_delete_range(c, BTREE_ID_alloc, start, end,
1592                                         BTREE_TRIGGER_NORUN, NULL) ?:
1593                 bch2_btree_delete_range(c, BTREE_ID_bucket_gens, start, end,
1594                                         BTREE_TRIGGER_NORUN, NULL);
1595         bch_err_msg(c, ret, "removing dev alloc info");
1596         return ret;
1597 }
1598
1599 int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
1600 {
1601         struct bch_member *m;
1602         unsigned dev_idx = ca->dev_idx, data;
1603         int ret;
1604
1605         down_write(&c->state_lock);
1606
1607         /*
1608          * We consume a reference to ca->ref, regardless of whether we succeed
1609          * or fail:
1610          */
1611         percpu_ref_put(&ca->ref);
1612
1613         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1614                 bch_err(ca, "Cannot remove without losing data");
1615                 ret = -BCH_ERR_device_state_not_allowed;
1616                 goto err;
1617         }
1618
1619         __bch2_dev_read_only(c, ca);
1620
1621         ret = bch2_dev_data_drop(c, ca->dev_idx, flags);
1622         bch_err_msg(ca, ret, "bch2_dev_data_drop()");
1623         if (ret)
1624                 goto err;
1625
1626         ret = bch2_dev_remove_alloc(c, ca);
1627         bch_err_msg(ca, ret, "bch2_dev_remove_alloc()");
1628         if (ret)
1629                 goto err;
1630
1631         ret = bch2_journal_flush_device_pins(&c->journal, ca->dev_idx);
1632         bch_err_msg(ca, ret, "bch2_journal_flush_device_pins()");
1633         if (ret)
1634                 goto err;
1635
1636         ret = bch2_journal_flush(&c->journal);
1637         bch_err_msg(ca, ret, "bch2_journal_flush()");
1638         if (ret)
1639                 goto err;
1640
1641         ret = bch2_replicas_gc2(c);
1642         bch_err_msg(ca, ret, "bch2_replicas_gc2()");
1643         if (ret)
1644                 goto err;
1645
1646         data = bch2_dev_has_data(c, ca);
1647         if (data) {
1648                 struct printbuf data_has = PRINTBUF;
1649
1650                 prt_bitflags(&data_has, __bch2_data_types, data);
1651                 bch_err(ca, "Remove failed, still has data (%s)", data_has.buf);
1652                 printbuf_exit(&data_has);
1653                 ret = -EBUSY;
1654                 goto err;
1655         }
1656
1657         __bch2_dev_offline(c, ca);
1658
1659         mutex_lock(&c->sb_lock);
1660         rcu_assign_pointer(c->devs[ca->dev_idx], NULL);
1661         mutex_unlock(&c->sb_lock);
1662
1663         percpu_ref_kill(&ca->ref);
1664         wait_for_completion(&ca->ref_completion);
1665
1666         bch2_dev_free(ca);
1667
1668         /*
1669          * At this point the device object has been removed in-core, but the
1670          * on-disk journal might still refer to the device index via sb device
1671          * usage entries. Recovery fails if it sees usage information for an
1672          * invalid device. Flush journal pins to push the back of the journal
1673          * past now invalid device index references before we update the
1674          * superblock, but after the device object has been removed so any
1675          * further journal writes elide usage info for the device.
1676          */
1677         bch2_journal_flush_all_pins(&c->journal);
1678
1679         /*
1680          * Free this device's slot in the bch_member array - all pointers to
1681          * this device must be gone:
1682          */
1683         mutex_lock(&c->sb_lock);
1684         m = bch2_members_v2_get_mut(c->disk_sb.sb, dev_idx);
1685         memset(&m->uuid, 0, sizeof(m->uuid));
1686
1687         bch2_write_super(c);
1688
1689         mutex_unlock(&c->sb_lock);
1690         up_write(&c->state_lock);
1691
1692         bch2_dev_usage_journal_reserve(c);
1693         return 0;
1694 err:
1695         if (ca->mi.state == BCH_MEMBER_STATE_rw &&
1696             !percpu_ref_is_zero(&ca->io_ref))
1697                 __bch2_dev_read_write(c, ca);
1698         up_write(&c->state_lock);
1699         return ret;
1700 }
1701
1702 /* Add new device to running filesystem: */
1703 int bch2_dev_add(struct bch_fs *c, const char *path)
1704 {
1705         struct bch_opts opts = bch2_opts_empty();
1706         struct bch_sb_handle sb;
1707         struct bch_dev *ca = NULL;
1708         struct bch_sb_field_members_v2 *mi;
1709         struct bch_member dev_mi;
1710         unsigned dev_idx, nr_devices, u64s;
1711         struct printbuf errbuf = PRINTBUF;
1712         struct printbuf label = PRINTBUF;
1713         int ret;
1714
1715         ret = bch2_read_super(path, &opts, &sb);
1716         bch_err_msg(c, ret, "reading super");
1717         if (ret)
1718                 goto err;
1719
1720         dev_mi = bch2_sb_member_get(sb.sb, sb.sb->dev_idx);
1721
1722         if (BCH_MEMBER_GROUP(&dev_mi)) {
1723                 bch2_disk_path_to_text_sb(&label, sb.sb, BCH_MEMBER_GROUP(&dev_mi) - 1);
1724                 if (label.allocation_failure) {
1725                         ret = -ENOMEM;
1726                         goto err;
1727                 }
1728         }
1729
1730         ret = bch2_dev_may_add(sb.sb, c);
1731         if (ret)
1732                 goto err;
1733
1734         ca = __bch2_dev_alloc(c, &dev_mi);
1735         if (!ca) {
1736                 ret = -ENOMEM;
1737                 goto err;
1738         }
1739
1740         bch2_dev_usage_init(ca);
1741
1742         ret = __bch2_dev_attach_bdev(ca, &sb);
1743         if (ret)
1744                 goto err;
1745
1746         ret = bch2_dev_journal_alloc(ca);
1747         bch_err_msg(c, ret, "allocating journal");
1748         if (ret)
1749                 goto err;
1750
1751         down_write(&c->state_lock);
1752         mutex_lock(&c->sb_lock);
1753
1754         ret = bch2_sb_from_fs(c, ca);
1755         bch_err_msg(c, ret, "setting up new superblock");
1756         if (ret)
1757                 goto err_unlock;
1758
1759         if (dynamic_fault("bcachefs:add:no_slot"))
1760                 goto no_slot;
1761
1762         for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
1763                 if (!bch2_dev_exists(c->disk_sb.sb, dev_idx))
1764                         goto have_slot;
1765 no_slot:
1766         ret = -BCH_ERR_ENOSPC_sb_members;
1767         bch_err_msg(c, ret, "setting up new superblock");
1768         goto err_unlock;
1769
1770 have_slot:
1771         nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
1772
1773         mi = bch2_sb_field_get(c->disk_sb.sb, members_v2);
1774         u64s = DIV_ROUND_UP(sizeof(struct bch_sb_field_members_v2) +
1775                             le16_to_cpu(mi->member_bytes) * nr_devices, sizeof(u64));
1776
1777         mi = bch2_sb_field_resize(&c->disk_sb, members_v2, u64s);
1778         if (!mi) {
1779                 ret = -BCH_ERR_ENOSPC_sb_members;
1780                 bch_err_msg(c, ret, "setting up new superblock");
1781                 goto err_unlock;
1782         }
1783         struct bch_member *m = bch2_members_v2_get_mut(c->disk_sb.sb, dev_idx);
1784
1785         /* success: */
1786
1787         *m = dev_mi;
1788         m->last_mount = cpu_to_le64(ktime_get_real_seconds());
1789         c->disk_sb.sb->nr_devices       = nr_devices;
1790
1791         ca->disk_sb.sb->dev_idx = dev_idx;
1792         bch2_dev_attach(c, ca, dev_idx);
1793
1794         if (BCH_MEMBER_GROUP(&dev_mi)) {
1795                 ret = __bch2_dev_group_set(c, ca, label.buf);
1796                 bch_err_msg(c, ret, "creating new label");
1797                 if (ret)
1798                         goto err_unlock;
1799         }
1800
1801         bch2_write_super(c);
1802         mutex_unlock(&c->sb_lock);
1803
1804         bch2_dev_usage_journal_reserve(c);
1805
1806         ret = bch2_trans_mark_dev_sb(c, ca);
1807         bch_err_msg(ca, ret, "marking new superblock");
1808         if (ret)
1809                 goto err_late;
1810
1811         ret = bch2_fs_freespace_init(c);
1812         bch_err_msg(ca, ret, "initializing free space");
1813         if (ret)
1814                 goto err_late;
1815
1816         ca->new_fs_bucket_idx = 0;
1817
1818         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1819                 __bch2_dev_read_write(c, ca);
1820
1821         up_write(&c->state_lock);
1822         return 0;
1823
1824 err_unlock:
1825         mutex_unlock(&c->sb_lock);
1826         up_write(&c->state_lock);
1827 err:
1828         if (ca)
1829                 bch2_dev_free(ca);
1830         bch2_free_super(&sb);
1831         printbuf_exit(&label);
1832         printbuf_exit(&errbuf);
1833         bch_err_fn(c, ret);
1834         return ret;
1835 err_late:
1836         up_write(&c->state_lock);
1837         ca = NULL;
1838         goto err;
1839 }
1840
1841 /* Hot add existing device to running filesystem: */
1842 int bch2_dev_online(struct bch_fs *c, const char *path)
1843 {
1844         struct bch_opts opts = bch2_opts_empty();
1845         struct bch_sb_handle sb = { NULL };
1846         struct bch_dev *ca;
1847         unsigned dev_idx;
1848         int ret;
1849
1850         down_write(&c->state_lock);
1851
1852         ret = bch2_read_super(path, &opts, &sb);
1853         if (ret) {
1854                 up_write(&c->state_lock);
1855                 return ret;
1856         }
1857
1858         dev_idx = sb.sb->dev_idx;
1859
1860         ret = bch2_dev_in_fs(&c->disk_sb, &sb, &c->opts);
1861         bch_err_msg(c, ret, "bringing %s online", path);
1862         if (ret)
1863                 goto err;
1864
1865         ret = bch2_dev_attach_bdev(c, &sb);
1866         if (ret)
1867                 goto err;
1868
1869         ca = bch_dev_locked(c, dev_idx);
1870
1871         ret = bch2_trans_mark_dev_sb(c, ca);
1872         bch_err_msg(c, ret, "bringing %s online: error from bch2_trans_mark_dev_sb", path);
1873         if (ret)
1874                 goto err;
1875
1876         if (ca->mi.state == BCH_MEMBER_STATE_rw)
1877                 __bch2_dev_read_write(c, ca);
1878
1879         if (!ca->mi.freespace_initialized) {
1880                 ret = bch2_dev_freespace_init(c, ca, 0, ca->mi.nbuckets);
1881                 bch_err_msg(ca, ret, "initializing free space");
1882                 if (ret)
1883                         goto err;
1884         }
1885
1886         if (!ca->journal.nr) {
1887                 ret = bch2_dev_journal_alloc(ca);
1888                 bch_err_msg(ca, ret, "allocating journal");
1889                 if (ret)
1890                         goto err;
1891         }
1892
1893         mutex_lock(&c->sb_lock);
1894         bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx)->last_mount =
1895                 cpu_to_le64(ktime_get_real_seconds());
1896         bch2_write_super(c);
1897         mutex_unlock(&c->sb_lock);
1898
1899         up_write(&c->state_lock);
1900         return 0;
1901 err:
1902         up_write(&c->state_lock);
1903         bch2_free_super(&sb);
1904         return ret;
1905 }
1906
1907 int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
1908 {
1909         down_write(&c->state_lock);
1910
1911         if (!bch2_dev_is_online(ca)) {
1912                 bch_err(ca, "Already offline");
1913                 up_write(&c->state_lock);
1914                 return 0;
1915         }
1916
1917         if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1918                 bch_err(ca, "Cannot offline required disk");
1919                 up_write(&c->state_lock);
1920                 return -BCH_ERR_device_state_not_allowed;
1921         }
1922
1923         __bch2_dev_offline(c, ca);
1924
1925         up_write(&c->state_lock);
1926         return 0;
1927 }
1928
1929 int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
1930 {
1931         struct bch_member *m;
1932         u64 old_nbuckets;
1933         int ret = 0;
1934
1935         down_write(&c->state_lock);
1936         old_nbuckets = ca->mi.nbuckets;
1937
1938         if (nbuckets < ca->mi.nbuckets) {
1939                 bch_err(ca, "Cannot shrink yet");
1940                 ret = -EINVAL;
1941                 goto err;
1942         }
1943
1944         if (bch2_dev_is_online(ca) &&
1945             get_capacity(ca->disk_sb.bdev->bd_disk) <
1946             ca->mi.bucket_size * nbuckets) {
1947                 bch_err(ca, "New size larger than device");
1948                 ret = -BCH_ERR_device_size_too_small;
1949                 goto err;
1950         }
1951
1952         ret = bch2_dev_buckets_resize(c, ca, nbuckets);
1953         bch_err_msg(ca, ret, "resizing buckets");
1954         if (ret)
1955                 goto err;
1956
1957         ret = bch2_trans_mark_dev_sb(c, ca);
1958         if (ret)
1959                 goto err;
1960
1961         mutex_lock(&c->sb_lock);
1962         m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
1963         m->nbuckets = cpu_to_le64(nbuckets);
1964
1965         bch2_write_super(c);
1966         mutex_unlock(&c->sb_lock);
1967
1968         if (ca->mi.freespace_initialized) {
1969                 ret = bch2_dev_freespace_init(c, ca, old_nbuckets, nbuckets);
1970                 if (ret)
1971                         goto err;
1972
1973                 /*
1974                  * XXX: this is all wrong transactionally - we'll be able to do
1975                  * this correctly after the disk space accounting rewrite
1976                  */
1977                 ca->usage_base->d[BCH_DATA_free].buckets += nbuckets - old_nbuckets;
1978         }
1979
1980         bch2_recalc_capacity(c);
1981 err:
1982         up_write(&c->state_lock);
1983         return ret;
1984 }
1985
1986 /* return with ref on ca->ref: */
1987 struct bch_dev *bch2_dev_lookup(struct bch_fs *c, const char *name)
1988 {
1989         rcu_read_lock();
1990         for_each_member_device_rcu(c, ca, NULL)
1991                 if (!strcmp(name, ca->name)) {
1992                         rcu_read_unlock();
1993                         return ca;
1994                 }
1995         rcu_read_unlock();
1996         return ERR_PTR(-BCH_ERR_ENOENT_dev_not_found);
1997 }
1998
1999 /* Filesystem open: */
2000
2001 static inline int sb_cmp(struct bch_sb *l, struct bch_sb *r)
2002 {
2003         return  cmp_int(le64_to_cpu(l->seq), le64_to_cpu(r->seq)) ?:
2004                 cmp_int(le64_to_cpu(l->write_time), le64_to_cpu(r->write_time));
2005 }
2006
2007 struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
2008                             struct bch_opts opts)
2009 {
2010         DARRAY(struct bch_sb_handle) sbs = { 0 };
2011         struct bch_fs *c = NULL;
2012         struct bch_sb_handle *best = NULL;
2013         struct printbuf errbuf = PRINTBUF;
2014         int ret = 0;
2015
2016         if (!try_module_get(THIS_MODULE))
2017                 return ERR_PTR(-ENODEV);
2018
2019         if (!nr_devices) {
2020                 ret = -EINVAL;
2021                 goto err;
2022         }
2023
2024         ret = darray_make_room(&sbs, nr_devices);
2025         if (ret)
2026                 goto err;
2027
2028         for (unsigned i = 0; i < nr_devices; i++) {
2029                 struct bch_sb_handle sb = { NULL };
2030
2031                 ret = bch2_read_super(devices[i], &opts, &sb);
2032                 if (ret)
2033                         goto err;
2034
2035                 BUG_ON(darray_push(&sbs, sb));
2036         }
2037
2038         if (opts.nochanges && !opts.read_only) {
2039                 ret = -BCH_ERR_erofs_nochanges;
2040                 goto err_print;
2041         }
2042
2043         darray_for_each(sbs, sb)
2044                 if (!best || sb_cmp(sb->sb, best->sb) > 0)
2045                         best = sb;
2046
2047         darray_for_each_reverse(sbs, sb) {
2048                 ret = bch2_dev_in_fs(best, sb, &opts);
2049
2050                 if (ret == -BCH_ERR_device_has_been_removed ||
2051                     ret == -BCH_ERR_device_splitbrain) {
2052                         bch2_free_super(sb);
2053                         darray_remove_item(&sbs, sb);
2054                         best -= best > sb;
2055                         ret = 0;
2056                         continue;
2057                 }
2058
2059                 if (ret)
2060                         goto err_print;
2061         }
2062
2063         c = bch2_fs_alloc(best->sb, opts);
2064         ret = PTR_ERR_OR_ZERO(c);
2065         if (ret)
2066                 goto err;
2067
2068         down_write(&c->state_lock);
2069         darray_for_each(sbs, sb) {
2070                 ret = bch2_dev_attach_bdev(c, sb);
2071                 if (ret) {
2072                         up_write(&c->state_lock);
2073                         goto err;
2074                 }
2075         }
2076         up_write(&c->state_lock);
2077
2078         if (!bch2_fs_may_start(c)) {
2079                 ret = -BCH_ERR_insufficient_devices_to_start;
2080                 goto err_print;
2081         }
2082
2083         if (!c->opts.nostart) {
2084                 ret = bch2_fs_start(c);
2085                 if (ret)
2086                         goto err;
2087         }
2088 out:
2089         darray_for_each(sbs, sb)
2090                 bch2_free_super(sb);
2091         darray_exit(&sbs);
2092         printbuf_exit(&errbuf);
2093         module_put(THIS_MODULE);
2094         return c;
2095 err_print:
2096         pr_err("bch_fs_open err opening %s: %s",
2097                devices[0], bch2_err_str(ret));
2098 err:
2099         if (!IS_ERR_OR_NULL(c))
2100                 bch2_fs_stop(c);
2101         c = ERR_PTR(ret);
2102         goto out;
2103 }
2104
2105 /* Global interfaces/init */
2106
2107 static void bcachefs_exit(void)
2108 {
2109         bch2_debug_exit();
2110         bch2_vfs_exit();
2111         bch2_chardev_exit();
2112         bch2_btree_key_cache_exit();
2113         if (bcachefs_kset)
2114                 kset_unregister(bcachefs_kset);
2115 }
2116
2117 static int __init bcachefs_init(void)
2118 {
2119         bch2_bkey_pack_test();
2120
2121         if (!(bcachefs_kset = kset_create_and_add("bcachefs", NULL, fs_kobj)) ||
2122             bch2_btree_key_cache_init() ||
2123             bch2_chardev_init() ||
2124             bch2_vfs_init() ||
2125             bch2_debug_init())
2126                 goto err;
2127
2128         return 0;
2129 err:
2130         bcachefs_exit();
2131         return -ENOMEM;
2132 }
2133
2134 #define BCH_DEBUG_PARAM(name, description)                      \
2135         bool bch2_##name;                                       \
2136         module_param_named(name, bch2_##name, bool, 0644);      \
2137         MODULE_PARM_DESC(name, description);
2138 BCH_DEBUG_PARAMS()
2139 #undef BCH_DEBUG_PARAM
2140
2141 __maybe_unused
2142 static unsigned bch2_metadata_version = bcachefs_metadata_version_current;
2143 module_param_named(version, bch2_metadata_version, uint, 0400);
2144
2145 module_exit(bcachefs_exit);
2146 module_init(bcachefs_init);