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   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 "trace.h"
  60
  61#include <linux/backing-dev.h>
  62#include <linux/blkdev.h>
  63#include <linux/debugfs.h>
  64#include <linux/device.h>
  65#include <linux/idr.h>
  66#include <linux/module.h>
  67#include <linux/percpu.h>
  68#include <linux/random.h>
  69#include <linux/sysfs.h>
  70#include <crypto/hash.h>
  71
  72MODULE_LICENSE("GPL");
  73MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
  74MODULE_DESCRIPTION("bcachefs filesystem");
  75MODULE_SOFTDEP("pre: crc32c");
  76MODULE_SOFTDEP("pre: crc64");
  77MODULE_SOFTDEP("pre: sha256");
  78MODULE_SOFTDEP("pre: chacha20");
  79MODULE_SOFTDEP("pre: poly1305");
  80MODULE_SOFTDEP("pre: xxhash");
  81
  82const char * const bch2_fs_flag_strs[] = {
  83#define x(n)		#n,
  84	BCH_FS_FLAGS()
  85#undef x
  86	NULL
  87};
  88
  89void __bch2_print(struct bch_fs *c, const char *fmt, ...)
  90{
  91	struct stdio_redirect *stdio = bch2_fs_stdio_redirect(c);
  92
  93	va_list args;
  94	va_start(args, fmt);
  95	if (likely(!stdio)) {
  96		vprintk(fmt, args);
  97	} else {
  98		unsigned long flags;
  99
 100		if (fmt[0] == KERN_SOH[0])
 101			fmt += 2;
 102
 103		spin_lock_irqsave(&stdio->output_lock, flags);
 104		prt_vprintf(&stdio->output_buf, fmt, args);
 105		spin_unlock_irqrestore(&stdio->output_lock, flags);
 106
 107		wake_up(&stdio->output_wait);
 108	}
 109	va_end(args);
 110}
 111
 112#define KTYPE(type)							\
 113static const struct attribute_group type ## _group = {			\
 114	.attrs = type ## _files						\
 115};									\
 116									\
 117static const struct attribute_group *type ## _groups[] = {		\
 118	&type ## _group,						\
 119	NULL								\
 120};									\
 121									\
 122static const struct kobj_type type ## _ktype = {			\
 123	.release	= type ## _release,				\
 124	.sysfs_ops	= &type ## _sysfs_ops,				\
 125	.default_groups = type ## _groups				\
 126}
 127
 128static void bch2_fs_release(struct kobject *);
 129static void bch2_dev_release(struct kobject *);
 130static void bch2_fs_counters_release(struct kobject *k)
 131{
 132}
 133
 134static void bch2_fs_internal_release(struct kobject *k)
 135{
 136}
 137
 138static void bch2_fs_opts_dir_release(struct kobject *k)
 139{
 140}
 141
 142static void bch2_fs_time_stats_release(struct kobject *k)
 143{
 144}
 145
 146KTYPE(bch2_fs);
 147KTYPE(bch2_fs_counters);
 148KTYPE(bch2_fs_internal);
 149KTYPE(bch2_fs_opts_dir);
 150KTYPE(bch2_fs_time_stats);
 151KTYPE(bch2_dev);
 152
 153static struct kset *bcachefs_kset;
 154static LIST_HEAD(bch_fs_list);
 155static DEFINE_MUTEX(bch_fs_list_lock);
 156
 157DECLARE_WAIT_QUEUE_HEAD(bch2_read_only_wait);
 158
 159static void bch2_dev_free(struct bch_dev *);
 160static int bch2_dev_alloc(struct bch_fs *, unsigned);
 161static int bch2_dev_sysfs_online(struct bch_fs *, struct bch_dev *);
 162static void __bch2_dev_read_only(struct bch_fs *, struct bch_dev *);
 163
 164struct bch_fs *bch2_dev_to_fs(dev_t dev)
 165{
 166	struct bch_fs *c;
 167
 168	mutex_lock(&bch_fs_list_lock);
 169	rcu_read_lock();
 170
 171	list_for_each_entry(c, &bch_fs_list, list)
 172		for_each_member_device_rcu(c, ca, NULL)
 173			if (ca->disk_sb.bdev && ca->disk_sb.bdev->bd_dev == dev) {
 174				closure_get(&c->cl);
 175				goto found;
 176			}
 177	c = NULL;
 178found:
 179	rcu_read_unlock();
 180	mutex_unlock(&bch_fs_list_lock);
 181
 182	return c;
 183}
 184
 185static struct bch_fs *__bch2_uuid_to_fs(__uuid_t uuid)
 186{
 187	struct bch_fs *c;
 188
 189	lockdep_assert_held(&bch_fs_list_lock);
 190
 191	list_for_each_entry(c, &bch_fs_list, list)
 192		if (!memcmp(&c->disk_sb.sb->uuid, &uuid, sizeof(uuid)))
 193			return c;
 194
 195	return NULL;
 196}
 197
 198struct bch_fs *bch2_uuid_to_fs(__uuid_t uuid)
 199{
 200	struct bch_fs *c;
 201
 202	mutex_lock(&bch_fs_list_lock);
 203	c = __bch2_uuid_to_fs(uuid);
 204	if (c)
 205		closure_get(&c->cl);
 206	mutex_unlock(&bch_fs_list_lock);
 207
 208	return c;
 209}
 210
 211static void bch2_dev_usage_journal_reserve(struct bch_fs *c)
 212{
 213	unsigned nr = 0, u64s =
 214		((sizeof(struct jset_entry_dev_usage) +
 215		  sizeof(struct jset_entry_dev_usage_type) * BCH_DATA_NR)) /
 216		sizeof(u64);
 217
 218	rcu_read_lock();
 219	for_each_member_device_rcu(c, ca, NULL)
 220		nr++;
 221	rcu_read_unlock();
 222
 223	bch2_journal_entry_res_resize(&c->journal,
 224			&c->dev_usage_journal_res, u64s * nr);
 225}
 226
 227/* Filesystem RO/RW: */
 228
 229/*
 230 * For startup/shutdown of RW stuff, the dependencies are:
 231 *
 232 * - foreground writes depend on copygc and rebalance (to free up space)
 233 *
 234 * - copygc and rebalance depend on mark and sweep gc (they actually probably
 235 *   don't because they either reserve ahead of time or don't block if
 236 *   allocations fail, but allocations can require mark and sweep gc to run
 237 *   because of generation number wraparound)
 238 *
 239 * - all of the above depends on the allocator threads
 240 *
 241 * - allocator depends on the journal (when it rewrites prios and gens)
 242 */
 243
 244static void __bch2_fs_read_only(struct bch_fs *c)
 245{
 246	unsigned clean_passes = 0;
 247	u64 seq = 0;
 248
 249	bch2_fs_ec_stop(c);
 250	bch2_open_buckets_stop(c, NULL, true);
 251	bch2_rebalance_stop(c);
 252	bch2_copygc_stop(c);
 253	bch2_gc_thread_stop(c);
 254	bch2_fs_ec_flush(c);
 255
 256	bch_verbose(c, "flushing journal and stopping allocators, journal seq %llu",
 257		    journal_cur_seq(&c->journal));
 258
 259	do {
 260		clean_passes++;
 261
 262		if (bch2_btree_interior_updates_flush(c) ||
 263		    bch2_journal_flush_all_pins(&c->journal) ||
 264		    bch2_btree_flush_all_writes(c) ||
 265		    seq != atomic64_read(&c->journal.seq)) {
 266			seq = atomic64_read(&c->journal.seq);
 267			clean_passes = 0;
 268		}
 269	} while (clean_passes < 2);
 270
 271	bch_verbose(c, "flushing journal and stopping allocators complete, journal seq %llu",
 272		    journal_cur_seq(&c->journal));
 273
 274	if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
 275	    !test_bit(BCH_FS_emergency_ro, &c->flags))
 276		set_bit(BCH_FS_clean_shutdown, &c->flags);
 277	bch2_fs_journal_stop(&c->journal);
 278
 279	/*
 280	 * After stopping journal:
 281	 */
 282	for_each_member_device(c, ca)
 283		bch2_dev_allocator_remove(c, ca);
 284}
 285
 286#ifndef BCH_WRITE_REF_DEBUG
 287static void bch2_writes_disabled(struct percpu_ref *writes)
 288{
 289	struct bch_fs *c = container_of(writes, struct bch_fs, writes);
 290
 291	set_bit(BCH_FS_write_disable_complete, &c->flags);
 292	wake_up(&bch2_read_only_wait);
 293}
 294#endif
 295
 296void bch2_fs_read_only(struct bch_fs *c)
 297{
 298	if (!test_bit(BCH_FS_rw, &c->flags)) {
 299		bch2_journal_reclaim_stop(&c->journal);
 300		return;
 301	}
 302
 303	BUG_ON(test_bit(BCH_FS_write_disable_complete, &c->flags));
 304
 305	bch_verbose(c, "going read-only");
 306
 307	/*
 308	 * Block new foreground-end write operations from starting - any new
 309	 * writes will return -EROFS:
 310	 */
 311	set_bit(BCH_FS_going_ro, &c->flags);
 312#ifndef BCH_WRITE_REF_DEBUG
 313	percpu_ref_kill(&c->writes);
 314#else
 315	for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++)
 316		bch2_write_ref_put(c, i);
 317#endif
 318
 319	/*
 320	 * If we're not doing an emergency shutdown, we want to wait on
 321	 * outstanding writes to complete so they don't see spurious errors due
 322	 * to shutting down the allocator:
 323	 *
 324	 * If we are doing an emergency shutdown outstanding writes may
 325	 * hang until we shutdown the allocator so we don't want to wait
 326	 * on outstanding writes before shutting everything down - but
 327	 * we do need to wait on them before returning and signalling
 328	 * that going RO is complete:
 329	 */
 330	wait_event(bch2_read_only_wait,
 331		   test_bit(BCH_FS_write_disable_complete, &c->flags) ||
 332		   test_bit(BCH_FS_emergency_ro, &c->flags));
 333
 334	bool writes_disabled = test_bit(BCH_FS_write_disable_complete, &c->flags);
 335	if (writes_disabled)
 336		bch_verbose(c, "finished waiting for writes to stop");
 337
 338	__bch2_fs_read_only(c);
 339
 340	wait_event(bch2_read_only_wait,
 341		   test_bit(BCH_FS_write_disable_complete, &c->flags));
 342
 343	if (!writes_disabled)
 344		bch_verbose(c, "finished waiting for writes to stop");
 345
 346	clear_bit(BCH_FS_write_disable_complete, &c->flags);
 347	clear_bit(BCH_FS_going_ro, &c->flags);
 348	clear_bit(BCH_FS_rw, &c->flags);
 349
 350	if (!bch2_journal_error(&c->journal) &&
 351	    !test_bit(BCH_FS_error, &c->flags) &&
 352	    !test_bit(BCH_FS_emergency_ro, &c->flags) &&
 353	    test_bit(BCH_FS_started, &c->flags) &&
 354	    test_bit(BCH_FS_clean_shutdown, &c->flags) &&
 355	    !c->opts.norecovery) {
 356		BUG_ON(c->journal.last_empty_seq != journal_cur_seq(&c->journal));
 357		BUG_ON(atomic_read(&c->btree_cache.dirty));
 358		BUG_ON(atomic_long_read(&c->btree_key_cache.nr_dirty));
 359		BUG_ON(c->btree_write_buffer.inc.keys.nr);
 360		BUG_ON(c->btree_write_buffer.flushing.keys.nr);
 361
 362		bch_verbose(c, "marking filesystem clean");
 363		bch2_fs_mark_clean(c);
 364	} else {
 365		bch_verbose(c, "done going read-only, filesystem not clean");
 366	}
 367}
 368
 369static void bch2_fs_read_only_work(struct work_struct *work)
 370{
 371	struct bch_fs *c =
 372		container_of(work, struct bch_fs, read_only_work);
 373
 374	down_write(&c->state_lock);
 375	bch2_fs_read_only(c);
 376	up_write(&c->state_lock);
 377}
 378
 379static void bch2_fs_read_only_async(struct bch_fs *c)
 380{
 381	queue_work(system_long_wq, &c->read_only_work);
 382}
 383
 384bool bch2_fs_emergency_read_only(struct bch_fs *c)
 385{
 386	bool ret = !test_and_set_bit(BCH_FS_emergency_ro, &c->flags);
 387
 388	bch2_journal_halt(&c->journal);
 389	bch2_fs_read_only_async(c);
 390
 391	wake_up(&bch2_read_only_wait);
 392	return ret;
 393}
 394
 395static int bch2_fs_read_write_late(struct bch_fs *c)
 396{
 397	int ret;
 398
 399	/*
 400	 * Data move operations can't run until after check_snapshots has
 401	 * completed, and bch2_snapshot_is_ancestor() is available.
 402	 *
 403	 * Ideally we'd start copygc/rebalance earlier instead of waiting for
 404	 * all of recovery/fsck to complete:
 405	 */
 406	ret = bch2_copygc_start(c);
 407	if (ret) {
 408		bch_err(c, "error starting copygc thread");
 409		return ret;
 410	}
 411
 412	ret = bch2_rebalance_start(c);
 413	if (ret) {
 414		bch_err(c, "error starting rebalance thread");
 415		return ret;
 416	}
 417
 418	return 0;
 419}
 420
 421static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 422{
 423	int ret;
 424
 425	if (test_bit(BCH_FS_initial_gc_unfixed, &c->flags)) {
 426		bch_err(c, "cannot go rw, unfixed btree errors");
 427		return -BCH_ERR_erofs_unfixed_errors;
 428	}
 429
 430	if (test_bit(BCH_FS_rw, &c->flags))
 431		return 0;
 432
 433	bch_info(c, "going read-write");
 434
 435	ret = bch2_sb_members_v2_init(c);
 436	if (ret)
 437		goto err;
 438
 439	ret = bch2_fs_mark_dirty(c);
 440	if (ret)
 441		goto err;
 442
 443	clear_bit(BCH_FS_clean_shutdown, &c->flags);
 444
 445	/*
 446	 * First journal write must be a flush write: after a clean shutdown we
 447	 * don't read the journal, so the first journal write may end up
 448	 * overwriting whatever was there previously, and there must always be
 449	 * at least one non-flush write in the journal or recovery will fail:
 450	 */
 451	set_bit(JOURNAL_NEED_FLUSH_WRITE, &c->journal.flags);
 452
 453	for_each_rw_member(c, ca)
 454		bch2_dev_allocator_add(c, ca);
 455	bch2_recalc_capacity(c);
 456
 457	set_bit(BCH_FS_rw, &c->flags);
 458	set_bit(BCH_FS_was_rw, &c->flags);
 459
 460#ifndef BCH_WRITE_REF_DEBUG
 461	percpu_ref_reinit(&c->writes);
 462#else
 463	for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) {
 464		BUG_ON(atomic_long_read(&c->writes[i]));
 465		atomic_long_inc(&c->writes[i]);
 466	}
 467#endif
 468
 469	ret = bch2_gc_thread_start(c);
 470	if (ret) {
 471		bch_err(c, "error starting gc thread");
 472		return ret;
 473	}
 474
 475	ret = bch2_journal_reclaim_start(&c->journal);
 476	if (ret)
 477		goto err;
 478
 479	if (!early) {
 480		ret = bch2_fs_read_write_late(c);
 481		if (ret)
 482			goto err;
 483	}
 484
 485	bch2_do_discards(c);
 486	bch2_do_invalidates(c);
 487	bch2_do_stripe_deletes(c);
 488	bch2_do_pending_node_rewrites(c);
 489	return 0;
 490err:
 491	if (test_bit(BCH_FS_rw, &c->flags))
 492		bch2_fs_read_only(c);
 493	else
 494		__bch2_fs_read_only(c);
 495	return ret;
 496}
 497
 498int bch2_fs_read_write(struct bch_fs *c)
 499{
 500	if (c->opts.norecovery)
 501		return -BCH_ERR_erofs_norecovery;
 502
 503	if (c->opts.nochanges)
 504		return -BCH_ERR_erofs_nochanges;
 505
 506	return __bch2_fs_read_write(c, false);
 507}
 508
 509int bch2_fs_read_write_early(struct bch_fs *c)
 510{
 511	lockdep_assert_held(&c->state_lock);
 512
 513	return __bch2_fs_read_write(c, true);
 514}
 515
 516/* Filesystem startup/shutdown: */
 517
 518static void __bch2_fs_free(struct bch_fs *c)
 519{
 520	unsigned i;
 521
 522	for (i = 0; i < BCH_TIME_STAT_NR; i++)
 523		bch2_time_stats_exit(&c->times[i]);
 524
 525	bch2_free_pending_node_rewrites(c);
 526	bch2_fs_sb_errors_exit(c);
 527	bch2_fs_counters_exit(c);
 528	bch2_fs_snapshots_exit(c);
 529	bch2_fs_quota_exit(c);
 530	bch2_fs_fs_io_direct_exit(c);
 531	bch2_fs_fs_io_buffered_exit(c);
 532	bch2_fs_fsio_exit(c);
 533	bch2_fs_ec_exit(c);
 534	bch2_fs_encryption_exit(c);
 535	bch2_fs_nocow_locking_exit(c);
 536	bch2_fs_io_write_exit(c);
 537	bch2_fs_io_read_exit(c);
 538	bch2_fs_buckets_waiting_for_journal_exit(c);
 539	bch2_fs_btree_interior_update_exit(c);
 540	bch2_fs_btree_iter_exit(c);
 541	bch2_fs_btree_key_cache_exit(&c->btree_key_cache);
 542	bch2_fs_btree_cache_exit(c);
 543	bch2_fs_replicas_exit(c);
 544	bch2_fs_journal_exit(&c->journal);
 545	bch2_io_clock_exit(&c->io_clock[WRITE]);
 546	bch2_io_clock_exit(&c->io_clock[READ]);
 547	bch2_fs_compress_exit(c);
 548	bch2_journal_keys_put_initial(c);
 549	BUG_ON(atomic_read(&c->journal_keys.ref));
 550	bch2_fs_btree_write_buffer_exit(c);
 551	percpu_free_rwsem(&c->mark_lock);
 552	free_percpu(c->online_reserved);
 553
 554	darray_exit(&c->btree_roots_extra);
 555	free_percpu(c->pcpu);
 556	mempool_exit(&c->large_bkey_pool);
 557	mempool_exit(&c->btree_bounce_pool);
 558	bioset_exit(&c->btree_bio);
 559	mempool_exit(&c->fill_iter);
 560#ifndef BCH_WRITE_REF_DEBUG
 561	percpu_ref_exit(&c->writes);
 562#endif
 563	kfree(rcu_dereference_protected(c->disk_groups, 1));
 564	kfree(c->journal_seq_blacklist_table);
 565	kfree(c->unused_inode_hints);
 566
 567	if (c->write_ref_wq)
 568		destroy_workqueue(c->write_ref_wq);
 569	if (c->io_complete_wq)
 570		destroy_workqueue(c->io_complete_wq);
 571	if (c->copygc_wq)
 572		destroy_workqueue(c->copygc_wq);
 573	if (c->btree_io_complete_wq)
 574		destroy_workqueue(c->btree_io_complete_wq);
 575	if (c->btree_update_wq)
 576		destroy_workqueue(c->btree_update_wq);
 577
 578	bch2_free_super(&c->disk_sb);
 579	kvpfree(c, sizeof(*c));
 580	module_put(THIS_MODULE);
 581}
 582
 583static void bch2_fs_release(struct kobject *kobj)
 584{
 585	struct bch_fs *c = container_of(kobj, struct bch_fs, kobj);
 586
 587	__bch2_fs_free(c);
 588}
 589
 590void __bch2_fs_stop(struct bch_fs *c)
 591{
 592	bch_verbose(c, "shutting down");
 593
 594	set_bit(BCH_FS_stopping, &c->flags);
 595
 596	cancel_work_sync(&c->journal_seq_blacklist_gc_work);
 597
 598	down_write(&c->state_lock);
 599	bch2_fs_read_only(c);
 600	up_write(&c->state_lock);
 601
 602	for_each_member_device(c, ca)
 603		if (ca->kobj.state_in_sysfs &&
 604		    ca->disk_sb.bdev)
 605			sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
 606
 607	if (c->kobj.state_in_sysfs)
 608		kobject_del(&c->kobj);
 609
 610	bch2_fs_debug_exit(c);
 611	bch2_fs_chardev_exit(c);
 612
 613	bch2_ro_ref_put(c);
 614	wait_event(c->ro_ref_wait, !refcount_read(&c->ro_ref));
 615
 616	kobject_put(&c->counters_kobj);
 617	kobject_put(&c->time_stats);
 618	kobject_put(&c->opts_dir);
 619	kobject_put(&c->internal);
 620
 621	/* btree prefetch might have kicked off reads in the background: */
 622	bch2_btree_flush_all_reads(c);
 623
 624	for_each_member_device(c, ca)
 625		cancel_work_sync(&ca->io_error_work);
 626
 627	cancel_work_sync(&c->read_only_work);
 628}
 629
 630void bch2_fs_free(struct bch_fs *c)
 631{
 632	unsigned i;
 633
 634	mutex_lock(&bch_fs_list_lock);
 635	list_del(&c->list);
 636	mutex_unlock(&bch_fs_list_lock);
 637
 638	closure_sync(&c->cl);
 639	closure_debug_destroy(&c->cl);
 640
 641	for (i = 0; i < c->sb.nr_devices; i++) {
 642		struct bch_dev *ca = rcu_dereference_protected(c->devs[i], true);
 643
 644		if (ca) {
 645			bch2_free_super(&ca->disk_sb);
 646			bch2_dev_free(ca);
 647		}
 648	}
 649
 650	bch_verbose(c, "shutdown complete");
 651
 652	kobject_put(&c->kobj);
 653}
 654
 655void bch2_fs_stop(struct bch_fs *c)
 656{
 657	__bch2_fs_stop(c);
 658	bch2_fs_free(c);
 659}
 660
 661static int bch2_fs_online(struct bch_fs *c)
 662{
 663	int ret = 0;
 664
 665	lockdep_assert_held(&bch_fs_list_lock);
 666
 667	if (__bch2_uuid_to_fs(c->sb.uuid)) {
 668		bch_err(c, "filesystem UUID already open");
 669		return -EINVAL;
 670	}
 671
 672	ret = bch2_fs_chardev_init(c);
 673	if (ret) {
 674		bch_err(c, "error creating character device");
 675		return ret;
 676	}
 677
 678	bch2_fs_debug_init(c);
 679
 680	ret = kobject_add(&c->kobj, NULL, "%pU", c->sb.user_uuid.b) ?:
 681	    kobject_add(&c->internal, &c->kobj, "internal") ?:
 682	    kobject_add(&c->opts_dir, &c->kobj, "options") ?:
 683#ifndef CONFIG_BCACHEFS_NO_LATENCY_ACCT
 684	    kobject_add(&c->time_stats, &c->kobj, "time_stats") ?:
 685#endif
 686	    kobject_add(&c->counters_kobj, &c->kobj, "counters") ?:
 687	    bch2_opts_create_sysfs_files(&c->opts_dir);
 688	if (ret) {
 689		bch_err(c, "error creating sysfs objects");
 690		return ret;
 691	}
 692
 693	down_write(&c->state_lock);
 694
 695	for_each_member_device(c, ca) {
 696		ret = bch2_dev_sysfs_online(c, ca);
 697		if (ret) {
 698			bch_err(c, "error creating sysfs objects");
 699			percpu_ref_put(&ca->ref);
 700			goto err;
 701		}
 702	}
 703
 704	BUG_ON(!list_empty(&c->list));
 705	list_add(&c->list, &bch_fs_list);
 706err:
 707	up_write(&c->state_lock);
 708	return ret;
 709}
 710
 711static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 712{
 713	struct bch_fs *c;
 714	struct printbuf name = PRINTBUF;
 715	unsigned i, iter_size;
 716	int ret = 0;
 717
 718	c = kvpmalloc(sizeof(struct bch_fs), GFP_KERNEL|__GFP_ZERO);
 719	if (!c) {
 720		c = ERR_PTR(-BCH_ERR_ENOMEM_fs_alloc);
 721		goto out;
 722	}
 723
 724	c->stdio = (void *)(unsigned long) opts.stdio;
 725
 726	__module_get(THIS_MODULE);
 727
 728	closure_init(&c->cl, NULL);
 729
 730	c->kobj.kset = bcachefs_kset;
 731	kobject_init(&c->kobj, &bch2_fs_ktype);
 732	kobject_init(&c->internal, &bch2_fs_internal_ktype);
 733	kobject_init(&c->opts_dir, &bch2_fs_opts_dir_ktype);
 734	kobject_init(&c->time_stats, &bch2_fs_time_stats_ktype);
 735	kobject_init(&c->counters_kobj, &bch2_fs_counters_ktype);
 736
 737	c->minor		= -1;
 738	c->disk_sb.fs_sb	= true;
 739
 740	init_rwsem(&c->state_lock);
 741	mutex_init(&c->sb_lock);
 742	mutex_init(&c->replicas_gc_lock);
 743	mutex_init(&c->btree_root_lock);
 744	INIT_WORK(&c->read_only_work, bch2_fs_read_only_work);
 745
 746	refcount_set(&c->ro_ref, 1);
 747	init_waitqueue_head(&c->ro_ref_wait);
 748	sema_init(&c->online_fsck_mutex, 1);
 749
 750	init_rwsem(&c->gc_lock);
 751	mutex_init(&c->gc_gens_lock);
 752	atomic_set(&c->journal_keys.ref, 1);
 753	c->journal_keys.initial_ref_held = true;
 754
 755	for (i = 0; i < BCH_TIME_STAT_NR; i++)
 756		bch2_time_stats_init(&c->times[i]);
 757
 758	bch2_fs_copygc_init(c);
 759	bch2_fs_btree_key_cache_init_early(&c->btree_key_cache);
 760	bch2_fs_btree_iter_init_early(c);
 761	bch2_fs_btree_interior_update_init_early(c);
 762	bch2_fs_allocator_background_init(c);
 763	bch2_fs_allocator_foreground_init(c);
 764	bch2_fs_rebalance_init(c);
 765	bch2_fs_quota_init(c);
 766	bch2_fs_ec_init_early(c);
 767	bch2_fs_move_init(c);
 768	bch2_fs_sb_errors_init_early(c);
 769
 770	INIT_LIST_HEAD(&c->list);
 771
 772	mutex_init(&c->usage_scratch_lock);
 773
 774	mutex_init(&c->bio_bounce_pages_lock);
 775	mutex_init(&c->snapshot_table_lock);
 776	init_rwsem(&c->snapshot_create_lock);
 777
 778	spin_lock_init(&c->btree_write_error_lock);
 779
 780	INIT_WORK(&c->journal_seq_blacklist_gc_work,
 781		  bch2_blacklist_entries_gc);
 782
 783	INIT_LIST_HEAD(&c->journal_iters);
 784
 785	INIT_LIST_HEAD(&c->fsck_error_msgs);
 786	mutex_init(&c->fsck_error_msgs_lock);
 787
 788	seqcount_init(&c->gc_pos_lock);
 789
 790	seqcount_init(&c->usage_lock);
 791
 792	sema_init(&c->io_in_flight, 128);
 793
 794	INIT_LIST_HEAD(&c->vfs_inodes_list);
 795	mutex_init(&c->vfs_inodes_lock);
 796
 797	c->copy_gc_enabled		= 1;
 798	c->rebalance.enabled		= 1;
 799	c->promote_whole_extents	= true;
 800
 801	c->journal.flush_write_time	= &c->times[BCH_TIME_journal_flush_write];
 802	c->journal.noflush_write_time	= &c->times[BCH_TIME_journal_noflush_write];
 803	c->journal.flush_seq_time	= &c->times[BCH_TIME_journal_flush_seq];
 804
 805	bch2_fs_btree_cache_init_early(&c->btree_cache);
 806
 807	mutex_init(&c->sectors_available_lock);
 808
 809	ret = percpu_init_rwsem(&c->mark_lock);
 810	if (ret)
 811		goto err;
 812
 813	mutex_lock(&c->sb_lock);
 814	ret = bch2_sb_to_fs(c, sb);
 815	mutex_unlock(&c->sb_lock);
 816
 817	if (ret)
 818		goto err;
 819
 820	pr_uuid(&name, c->sb.user_uuid.b);
 821	strscpy(c->name, name.buf, sizeof(c->name));
 822	printbuf_exit(&name);
 823
 824	ret = name.allocation_failure ? -BCH_ERR_ENOMEM_fs_name_alloc : 0;
 825	if (ret)
 826		goto err;
 827
 828	/* Compat: */
 829	if (le16_to_cpu(sb->version) <= bcachefs_metadata_version_inode_v2 &&
 830	    !BCH_SB_JOURNAL_FLUSH_DELAY(sb))
 831		SET_BCH_SB_JOURNAL_FLUSH_DELAY(sb, 1000);
 832
 833	if (le16_to_cpu(sb->version) <= bcachefs_metadata_version_inode_v2 &&
 834	    !BCH_SB_JOURNAL_RECLAIM_DELAY(sb))
 835		SET_BCH_SB_JOURNAL_RECLAIM_DELAY(sb, 100);
 836
 837	c->opts = bch2_opts_default;
 838	ret = bch2_opts_from_sb(&c->opts, sb);
 839	if (ret)
 840		goto err;
 841
 842	bch2_opts_apply(&c->opts, opts);
 843
 844	c->btree_key_cache_btrees |= 1U << BTREE_ID_alloc;
 845	if (c->opts.inodes_use_key_cache)
 846		c->btree_key_cache_btrees |= 1U << BTREE_ID_inodes;
 847	c->btree_key_cache_btrees |= 1U << BTREE_ID_logged_ops;
 848
 849	c->block_bits		= ilog2(block_sectors(c));
 850	c->btree_foreground_merge_threshold = BTREE_FOREGROUND_MERGE_THRESHOLD(c);
 851
 852	if (bch2_fs_init_fault("fs_alloc")) {
 853		bch_err(c, "fs_alloc fault injected");
 854		ret = -EFAULT;
 855		goto err;
 856	}
 857
 858	iter_size = sizeof(struct sort_iter) +
 859		(btree_blocks(c) + 1) * 2 *
 860		sizeof(struct sort_iter_set);
 861
 862	c->inode_shard_bits = ilog2(roundup_pow_of_two(num_possible_cpus()));
 863
 864	if (!(c->btree_update_wq = alloc_workqueue("bcachefs",
 865				WQ_FREEZABLE|WQ_UNBOUND|WQ_MEM_RECLAIM, 512)) ||
 866	    !(c->btree_io_complete_wq = alloc_workqueue("bcachefs_btree_io",
 867				WQ_FREEZABLE|WQ_MEM_RECLAIM, 1)) ||
 868	    !(c->copygc_wq = alloc_workqueue("bcachefs_copygc",
 869				WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
 870	    !(c->io_complete_wq = alloc_workqueue("bcachefs_io",
 871				WQ_FREEZABLE|WQ_HIGHPRI|WQ_MEM_RECLAIM, 512)) ||
 872	    !(c->write_ref_wq = alloc_workqueue("bcachefs_write_ref",
 873				WQ_FREEZABLE, 0)) ||
 874#ifndef BCH_WRITE_REF_DEBUG
 875	    percpu_ref_init(&c->writes, bch2_writes_disabled,
 876			    PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
 877#endif
 878	    mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
 879	    bioset_init(&c->btree_bio, 1,
 880			max(offsetof(struct btree_read_bio, bio),
 881			    offsetof(struct btree_write_bio, wbio.bio)),
 882			BIOSET_NEED_BVECS) ||
 883	    !(c->pcpu = alloc_percpu(struct bch_fs_pcpu)) ||
 884	    !(c->online_reserved = alloc_percpu(u64)) ||
 885	    mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
 886					c->opts.btree_node_size) ||
 887	    mempool_init_kmalloc_pool(&c->large_bkey_pool, 1, 2048) ||
 888	    !(c->unused_inode_hints = kcalloc(1U << c->inode_shard_bits,
 889					      sizeof(u64), GFP_KERNEL))) {
 890		ret = -BCH_ERR_ENOMEM_fs_other_alloc;
 891		goto err;
 892	}
 893
 894	ret = bch2_fs_counters_init(c) ?:
 895	    bch2_fs_sb_errors_init(c) ?:
 896	    bch2_io_clock_init(&c->io_clock[READ]) ?:
 897	    bch2_io_clock_init(&c->io_clock[WRITE]) ?:
 898	    bch2_fs_journal_init(&c->journal) ?:
 899	    bch2_fs_replicas_init(c) ?:
 900	    bch2_fs_btree_cache_init(c) ?:
 901	    bch2_fs_btree_key_cache_init(&c->btree_key_cache) ?:
 902	    bch2_fs_btree_iter_init(c) ?:
 903	    bch2_fs_btree_interior_update_init(c) ?:
 904	    bch2_fs_buckets_waiting_for_journal_init(c) ?:
 905	    bch2_fs_btree_write_buffer_init(c) ?:
 906	    bch2_fs_subvolumes_init(c) ?:
 907	    bch2_fs_io_read_init(c) ?:
 908	    bch2_fs_io_write_init(c) ?:
 909	    bch2_fs_nocow_locking_init(c) ?:
 910	    bch2_fs_encryption_init(c) ?:
 911	    bch2_fs_compress_init(c) ?:
 912	    bch2_fs_ec_init(c) ?:
 913	    bch2_fs_fsio_init(c) ?:
 914	    bch2_fs_fs_io_buffered_init(c) ?:
 915	    bch2_fs_fs_io_direct_init(c);
 916	if (ret)
 917		goto err;
 918
 919	for (i = 0; i < c->sb.nr_devices; i++)
 920		if (bch2_dev_exists(c->disk_sb.sb, i) &&
 921		    bch2_dev_alloc(c, i)) {
 922			ret = -EEXIST;
 923			goto err;
 924		}
 925
 926	bch2_journal_entry_res_resize(&c->journal,
 927			&c->btree_root_journal_res,
 928			BTREE_ID_NR * (JSET_KEYS_U64s + BKEY_BTREE_PTR_U64s_MAX));
 929	bch2_dev_usage_journal_reserve(c);
 930	bch2_journal_entry_res_resize(&c->journal,
 931			&c->clock_journal_res,
 932			(sizeof(struct jset_entry_clock) / sizeof(u64)) * 2);
 933
 934	mutex_lock(&bch_fs_list_lock);
 935	ret = bch2_fs_online(c);
 936	mutex_unlock(&bch_fs_list_lock);
 937
 938	if (ret)
 939		goto err;
 940out:
 941	return c;
 942err:
 943	bch2_fs_free(c);
 944	c = ERR_PTR(ret);
 945	goto out;
 946}
 947
 948noinline_for_stack
 949static void print_mount_opts(struct bch_fs *c)
 950{
 951	enum bch_opt_id i;
 952	struct printbuf p = PRINTBUF;
 953	bool first = true;
 954
 955	prt_str(&p, "mounting version ");
 956	bch2_version_to_text(&p, c->sb.version);
 957
 958	if (c->opts.read_only) {
 959		prt_str(&p, " opts=");
 960		first = false;
 961		prt_printf(&p, "ro");
 962	}
 963
 964	for (i = 0; i < bch2_opts_nr; i++) {
 965		const struct bch_option *opt = &bch2_opt_table[i];
 966		u64 v = bch2_opt_get_by_id(&c->opts, i);
 967
 968		if (!(opt->flags & OPT_MOUNT))
 969			continue;
 970
 971		if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
 972			continue;
 973
 974		prt_str(&p, first ? " opts=" : ",");
 975		first = false;
 976		bch2_opt_to_text(&p, c, c->disk_sb.sb, opt, v, OPT_SHOW_MOUNT_STYLE);
 977	}
 978
 979	bch_info(c, "%s", p.buf);
 980	printbuf_exit(&p);
 981}
 982
 983int bch2_fs_start(struct bch_fs *c)
 984{
 985	time64_t now = ktime_get_real_seconds();
 986	int ret;
 987
 988	print_mount_opts(c);
 989
 990	down_write(&c->state_lock);
 991
 992	BUG_ON(test_bit(BCH_FS_started, &c->flags));
 993
 994	mutex_lock(&c->sb_lock);
 995
 996	ret = bch2_sb_members_v2_init(c);
 997	if (ret) {
 998		mutex_unlock(&c->sb_lock);
 999		goto err;
1000	}
1001
1002	for_each_online_member(c, ca)
1003		bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx)->last_mount = cpu_to_le64(now);
1004
1005	mutex_unlock(&c->sb_lock);
1006
1007	for_each_rw_member(c, ca)
1008		bch2_dev_allocator_add(c, ca);
1009	bch2_recalc_capacity(c);
1010
1011	ret = BCH_SB_INITIALIZED(c->disk_sb.sb)
1012		? bch2_fs_recovery(c)
1013		: bch2_fs_initialize(c);
1014	if (ret)
1015		goto err;
1016
1017	ret = bch2_opts_check_may_set(c);
1018	if (ret)
1019		goto err;
1020
1021	if (bch2_fs_init_fault("fs_start")) {
1022		bch_err(c, "fs_start fault injected");
1023		ret = -EINVAL;
1024		goto err;
1025	}
1026
1027	set_bit(BCH_FS_started, &c->flags);
1028
1029	if (c->opts.read_only) {
1030		bch2_fs_read_only(c);
1031	} else {
1032		ret = !test_bit(BCH_FS_rw, &c->flags)
1033			? bch2_fs_read_write(c)
1034			: bch2_fs_read_write_late(c);
1035		if (ret)
1036			goto err;
1037	}
1038
1039	ret = 0;
1040err:
1041	if (ret)
1042		bch_err_msg(c, ret, "starting filesystem");
1043	else
1044		bch_verbose(c, "done starting filesystem");
1045	up_write(&c->state_lock);
1046	return ret;
1047}
1048
1049static int bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
1050{
1051	struct bch_member m = bch2_sb_member_get(sb, sb->dev_idx);
1052
1053	if (le16_to_cpu(sb->block_size) != block_sectors(c))
1054		return -BCH_ERR_mismatched_block_size;
1055
1056	if (le16_to_cpu(m.bucket_size) <
1057	    BCH_SB_BTREE_NODE_SIZE(c->disk_sb.sb))
1058		return -BCH_ERR_bucket_size_too_small;
1059
1060	return 0;
1061}
1062
1063static int bch2_dev_in_fs(struct bch_sb_handle *fs,
1064			  struct bch_sb_handle *sb)
1065{
1066	if (fs == sb)
1067		return 0;
1068
1069	if (!uuid_equal(&fs->sb->uuid, &sb->sb->uuid))
1070		return -BCH_ERR_device_not_a_member_of_filesystem;
1071
1072	if (!bch2_dev_exists(fs->sb, sb->sb->dev_idx))
1073		return -BCH_ERR_device_has_been_removed;
1074
1075	if (fs->sb->block_size != sb->sb->block_size)
1076		return -BCH_ERR_mismatched_block_size;
1077
1078	if (le16_to_cpu(fs->sb->version) < bcachefs_metadata_version_member_seq ||
1079	    le16_to_cpu(sb->sb->version) < bcachefs_metadata_version_member_seq)
1080		return 0;
1081
1082	if (fs->sb->seq == sb->sb->seq &&
1083	    fs->sb->write_time != sb->sb->write_time) {
1084		struct printbuf buf = PRINTBUF;
1085
1086		prt_str(&buf, "Split brain detected between ");
1087		prt_bdevname(&buf, sb->bdev);
1088		prt_str(&buf, " and ");
1089		prt_bdevname(&buf, fs->bdev);
1090		prt_char(&buf, ':');
1091		prt_newline(&buf);
1092		prt_printf(&buf, "seq=%llu but write_time different, got", le64_to_cpu(sb->sb->seq));
1093		prt_newline(&buf);
1094
1095		prt_bdevname(&buf, fs->bdev);
1096		prt_char(&buf, ' ');
1097		bch2_prt_datetime(&buf, le64_to_cpu(fs->sb->write_time));;
1098		prt_newline(&buf);
1099
1100		prt_bdevname(&buf, sb->bdev);
1101		prt_char(&buf, ' ');
1102		bch2_prt_datetime(&buf, le64_to_cpu(sb->sb->write_time));;
1103		prt_newline(&buf);
1104
1105		prt_printf(&buf, "Not using older sb");
1106
1107		pr_err("%s", buf.buf);
1108		printbuf_exit(&buf);
1109		return -BCH_ERR_device_splitbrain;
1110	}
1111
1112	struct bch_member m = bch2_sb_member_get(fs->sb, sb->sb->dev_idx);
1113	u64 seq_from_fs		= le64_to_cpu(m.seq);
1114	u64 seq_from_member	= le64_to_cpu(sb->sb->seq);
1115
1116	if (seq_from_fs && seq_from_fs < seq_from_member) {
1117		struct printbuf buf = PRINTBUF;
1118
1119		prt_str(&buf, "Split brain detected between ");
1120		prt_bdevname(&buf, sb->bdev);
1121		prt_str(&buf, " and ");
1122		prt_bdevname(&buf, fs->bdev);
1123		prt_char(&buf, ':');
1124		prt_newline(&buf);
1125
1126		prt_bdevname(&buf, fs->bdev);
1127		prt_str(&buf, "believes seq of ");
1128		prt_bdevname(&buf, sb->bdev);
1129		prt_printf(&buf, " to be %llu, but ", seq_from_fs);
1130		prt_bdevname(&buf, sb->bdev);
1131		prt_printf(&buf, " has %llu\n", seq_from_member);
1132		prt_str(&buf, "Not using ");
1133		prt_bdevname(&buf, sb->bdev);
1134
1135		pr_err("%s", buf.buf);
1136		printbuf_exit(&buf);
1137		return -BCH_ERR_device_splitbrain;
1138	}
1139
1140	return 0;
1141}
1142
1143/* Device startup/shutdown: */
1144
1145static void bch2_dev_release(struct kobject *kobj)
1146{
1147	struct bch_dev *ca = container_of(kobj, struct bch_dev, kobj);
1148
1149	kfree(ca);
1150}
1151
1152static void bch2_dev_free(struct bch_dev *ca)
1153{
1154	cancel_work_sync(&ca->io_error_work);
1155
1156	if (ca->kobj.state_in_sysfs &&
1157	    ca->disk_sb.bdev)
1158		sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1159
1160	if (ca->kobj.state_in_sysfs)
1161		kobject_del(&ca->kobj);
1162
1163	bch2_free_super(&ca->disk_sb);
1164	bch2_dev_journal_exit(ca);
1165
1166	free_percpu(ca->io_done);
1167	bioset_exit(&ca->replica_set);
1168	bch2_dev_buckets_free(ca);
1169	free_page((unsigned long) ca->sb_read_scratch);
1170
1171	bch2_time_stats_exit(&ca->io_latency[WRITE]);
1172	bch2_time_stats_exit(&ca->io_latency[READ]);
1173
1174	percpu_ref_exit(&ca->io_ref);
1175	percpu_ref_exit(&ca->ref);
1176	kobject_put(&ca->kobj);
1177}
1178
1179static void __bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca)
1180{
1181
1182	lockdep_assert_held(&c->state_lock);
1183
1184	if (percpu_ref_is_zero(&ca->io_ref))
1185		return;
1186
1187	__bch2_dev_read_only(c, ca);
1188
1189	reinit_completion(&ca->io_ref_completion);
1190	percpu_ref_kill(&ca->io_ref);
1191	wait_for_completion(&ca->io_ref_completion);
1192
1193	if (ca->kobj.state_in_sysfs) {
1194		sysfs_remove_link(bdev_kobj(ca->disk_sb.bdev), "bcachefs");
1195		sysfs_remove_link(&ca->kobj, "block");
1196	}
1197
1198	bch2_free_super(&ca->disk_sb);
1199	bch2_dev_journal_exit(ca);
1200}
1201
1202static void bch2_dev_ref_complete(struct percpu_ref *ref)
1203{
1204	struct bch_dev *ca = container_of(ref, struct bch_dev, ref);
1205
1206	complete(&ca->ref_completion);
1207}
1208
1209static void bch2_dev_io_ref_complete(struct percpu_ref *ref)
1210{
1211	struct bch_dev *ca = container_of(ref, struct bch_dev, io_ref);
1212
1213	complete(&ca->io_ref_completion);
1214}
1215
1216static int bch2_dev_sysfs_online(struct bch_fs *c, struct bch_dev *ca)
1217{
1218	int ret;
1219
1220	if (!c->kobj.state_in_sysfs)
1221		return 0;
1222
1223	if (!ca->kobj.state_in_sysfs) {
1224		ret = kobject_add(&ca->kobj, &c->kobj,
1225				  "dev-%u", ca->dev_idx);
1226		if (ret)
1227			return ret;
1228	}
1229
1230	if (ca->disk_sb.bdev) {
1231		struct kobject *block = bdev_kobj(ca->disk_sb.bdev);
1232
1233		ret = sysfs_create_link(block, &ca->kobj, "bcachefs");
1234		if (ret)
1235			return ret;
1236
1237		ret = sysfs_create_link(&ca->kobj, block, "block");
1238		if (ret)
1239			return ret;
1240	}
1241
1242	return 0;
1243}
1244
1245static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
1246					struct bch_member *member)
1247{
1248	struct bch_dev *ca;
1249	unsigned i;
1250
1251	ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1252	if (!ca)
1253		return NULL;
1254
1255	kobject_init(&ca->kobj, &bch2_dev_ktype);
1256	init_completion(&ca->ref_completion);
1257	init_completion(&ca->io_ref_completion);
1258
1259	init_rwsem(&ca->bucket_lock);
1260
1261	INIT_WORK(&ca->io_error_work, bch2_io_error_work);
1262
1263	bch2_time_stats_init(&ca->io_latency[READ]);
1264	bch2_time_stats_init(&ca->io_latency[WRITE]);
1265
1266	ca->mi = bch2_mi_to_cpu(member);
1267
1268	for (i = 0; i < ARRAY_SIZE(member->errors); i++)
1269		atomic64_set(&ca->errors[i], le64_to_cpu(member->errors[i]));
1270
1271	ca->uuid = member->uuid;
1272
1273	ca->nr_btree_reserve = DIV_ROUND_UP(BTREE_NODE_RESERVE,
1274			     ca->mi.bucket_size / btree_sectors(c));
1275
1276	if (percpu_ref_init(&ca->ref, bch2_dev_ref_complete,
1277			    0, GFP_KERNEL) ||
1278	    percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
1279			    PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
1280	    !(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
1281	    bch2_dev_buckets_alloc(c, ca) ||
1282	    bioset_init(&ca->replica_set, 4,
1283			offsetof(struct bch_write_bio, bio), 0) ||
1284	    !(ca->io_done	= alloc_percpu(*ca->io_done)))
1285		goto err;
1286
1287	return ca;
1288err:
1289	bch2_dev_free(ca);
1290	return NULL;
1291}
1292
1293static void bch2_dev_attach(struct bch_fs *c, struct bch_dev *ca,
1294			    unsigned dev_idx)
1295{
1296	ca->dev_idx = dev_idx;
1297	__set_bit(ca->dev_idx, ca->self.d);
1298	scnprintf(ca->name, sizeof(ca->name), "dev-%u", dev_idx);
1299
1300	ca->fs = c;
1301	rcu_assign_pointer(c->devs[ca->dev_idx], ca);
1302
1303	if (bch2_dev_sysfs_online(c, ca))
1304		pr_warn("error creating sysfs objects");
1305}
1306
1307static int bch2_dev_alloc(struct bch_fs *c, unsigned dev_idx)
1308{
1309	struct bch_member member = bch2_sb_member_get(c->disk_sb.sb, dev_idx);
1310	struct bch_dev *ca = NULL;
1311	int ret = 0;
1312
1313	if (bch2_fs_init_fault("dev_alloc"))
1314		goto err;
1315
1316	ca = __bch2_dev_alloc(c, &member);
1317	if (!ca)
1318		goto err;
1319
1320	ca->fs = c;
1321
1322	bch2_dev_attach(c, ca, dev_idx);
1323	return ret;
1324err:
1325	if (ca)
1326		bch2_dev_free(ca);
1327	return -BCH_ERR_ENOMEM_dev_alloc;
1328}
1329
1330static int __bch2_dev_attach_bdev(struct bch_dev *ca, struct bch_sb_handle *sb)
1331{
1332	unsigned ret;
1333
1334	if (bch2_dev_is_online(ca)) {
1335		bch_err(ca, "already have device online in slot %u",
1336			sb->sb->dev_idx);
1337		return -BCH_ERR_device_already_online;
1338	}
1339
1340	if (get_capacity(sb->bdev->bd_disk) <
1341	    ca->mi.bucket_size * ca->mi.nbuckets) {
1342		bch_err(ca, "cannot online: device too small");
1343		return -BCH_ERR_device_size_too_small;
1344	}
1345
1346	BUG_ON(!percpu_ref_is_zero(&ca->io_ref));
1347
1348	ret = bch2_dev_journal_init(ca, sb->sb);
1349	if (ret)
1350		return ret;
1351
1352	/* Commit: */
1353	ca->disk_sb = *sb;
1354	memset(sb, 0, sizeof(*sb));
1355
1356	ca->dev = ca->disk_sb.bdev->bd_dev;
1357
1358	percpu_ref_reinit(&ca->io_ref);
1359
1360	return 0;
1361}
1362
1363static int bch2_dev_attach_bdev(struct bch_fs *c, struct bch_sb_handle *sb)
1364{
1365	struct bch_dev *ca;
1366	int ret;
1367
1368	lockdep_assert_held(&c->state_lock);
1369
1370	if (le64_to_cpu(sb->sb->seq) >
1371	    le64_to_cpu(c->disk_sb.sb->seq))
1372		bch2_sb_to_fs(c, sb->sb);
1373
1374	BUG_ON(sb->sb->dev_idx >= c->sb.nr_devices ||
1375	       !c->devs[sb->sb->dev_idx]);
1376
1377	ca = bch_dev_locked(c, sb->sb->dev_idx);
1378
1379	ret = __bch2_dev_attach_bdev(ca, sb);
1380	if (ret)
1381		return ret;
1382
1383	bch2_dev_sysfs_online(c, ca);
1384
1385	struct printbuf name = PRINTBUF;
1386	prt_bdevname(&name, ca->disk_sb.bdev);
1387
1388	if (c->sb.nr_devices == 1)
1389		strscpy(c->name, name.buf, sizeof(c->name));
1390	strscpy(ca->name, name.buf, sizeof(ca->name));
1391
1392	printbuf_exit(&name);
1393
1394	rebalance_wakeup(c);
1395	return 0;
1396}
1397
1398/* Device management: */
1399
1400/*
1401 * Note: this function is also used by the error paths - when a particular
1402 * device sees an error, we call it to determine whether we can just set the
1403 * device RO, or - if this function returns false - we'll set the whole
1404 * filesystem RO:
1405 *
1406 * XXX: maybe we should be more explicit about whether we're changing state
1407 * because we got an error or what have you?
1408 */
1409bool bch2_dev_state_allowed(struct bch_fs *c, struct bch_dev *ca,
1410			    enum bch_member_state new_state, int flags)
1411{
1412	struct bch_devs_mask new_online_devs;
1413	int nr_rw = 0, required;
1414
1415	lockdep_assert_held(&c->state_lock);
1416
1417	switch (new_state) {
1418	case BCH_MEMBER_STATE_rw:
1419		return true;
1420	case BCH_MEMBER_STATE_ro:
1421		if (ca->mi.state != BCH_MEMBER_STATE_rw)
1422			return true;
1423
1424		/* do we have enough devices to write to?  */
1425		for_each_member_device(c, ca2)
1426			if (ca2 != ca)
1427				nr_rw += ca2->mi.state == BCH_MEMBER_STATE_rw;
1428
1429		required = max(!(flags & BCH_FORCE_IF_METADATA_DEGRADED)
1430			       ? c->opts.metadata_replicas
1431			       : metadata_replicas_required(c),
1432			       !(flags & BCH_FORCE_IF_DATA_DEGRADED)
1433			       ? c->opts.data_replicas
1434			       : data_replicas_required(c));
1435
1436		return nr_rw >= required;
1437	case BCH_MEMBER_STATE_failed:
1438	case BCH_MEMBER_STATE_spare:
1439		if (ca->mi.state != BCH_MEMBER_STATE_rw &&
1440		    ca->mi.state != BCH_MEMBER_STATE_ro)
1441			return true;
1442
1443		/* do we have enough devices to read from?  */
1444		new_online_devs = bch2_online_devs(c);
1445		__clear_bit(ca->dev_idx, new_online_devs.d);
1446
1447		return bch2_have_enough_devs(c, new_online_devs, flags, false);
1448	default:
1449		BUG();
1450	}
1451}
1452
1453static bool bch2_fs_may_start(struct bch_fs *c)
1454{
1455	struct bch_dev *ca;
1456	unsigned i, flags = 0;
1457
1458	if (c->opts.very_degraded)
1459		flags |= BCH_FORCE_IF_DEGRADED|BCH_FORCE_IF_LOST;
1460
1461	if (c->opts.degraded)
1462		flags |= BCH_FORCE_IF_DEGRADED;
1463
1464	if (!c->opts.degraded &&
1465	    !c->opts.very_degraded) {
1466		mutex_lock(&c->sb_lock);
1467
1468		for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
1469			if (!bch2_dev_exists(c->disk_sb.sb, i))
1470				continue;
1471
1472			ca = bch_dev_locked(c, i);
1473
1474			if (!bch2_dev_is_online(ca) &&
1475			    (ca->mi.state == BCH_MEMBER_STATE_rw ||
1476			     ca->mi.state == BCH_MEMBER_STATE_ro)) {
1477				mutex_unlock(&c->sb_lock);
1478				return false;
1479			}
1480		}
1481		mutex_unlock(&c->sb_lock);
1482	}
1483
1484	return bch2_have_enough_devs(c, bch2_online_devs(c), flags, true);
1485}
1486
1487static void __bch2_dev_read_only(struct bch_fs *c, struct bch_dev *ca)
1488{
1489	/*
1490	 * The allocator thread itself allocates btree nodes, so stop it first:
1491	 */
1492	bch2_dev_allocator_remove(c, ca);
1493	bch2_dev_journal_stop(&c->journal, ca);
1494}
1495
1496static void __bch2_dev_read_write(struct bch_fs *c, struct bch_dev *ca)
1497{
1498	lockdep_assert_held(&c->state_lock);
1499
1500	BUG_ON(ca->mi.state != BCH_MEMBER_STATE_rw);
1501
1502	bch2_dev_allocator_add(c, ca);
1503	bch2_recalc_capacity(c);
1504}
1505
1506int __bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1507			 enum bch_member_state new_state, int flags)
1508{
1509	struct bch_member *m;
1510	int ret = 0;
1511
1512	if (ca->mi.state == new_state)
1513		return 0;
1514
1515	if (!bch2_dev_state_allowed(c, ca, new_state, flags))
1516		return -BCH_ERR_device_state_not_allowed;
1517
1518	if (new_state != BCH_MEMBER_STATE_rw)
1519		__bch2_dev_read_only(c, ca);
1520
1521	bch_notice(ca, "%s", bch2_member_states[new_state]);
1522
1523	mutex_lock(&c->sb_lock);
1524	m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
1525	SET_BCH_MEMBER_STATE(m, new_state);
1526	bch2_write_super(c);
1527	mutex_unlock(&c->sb_lock);
1528
1529	if (new_state == BCH_MEMBER_STATE_rw)
1530		__bch2_dev_read_write(c, ca);
1531
1532	rebalance_wakeup(c);
1533
1534	return ret;
1535}
1536
1537int bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
1538		       enum bch_member_state new_state, int flags)
1539{
1540	int ret;
1541
1542	down_write(&c->state_lock);
1543	ret = __bch2_dev_set_state(c, ca, new_state, flags);
1544	up_write(&c->state_lock);
1545
1546	return ret;
1547}
1548
1549/* Device add/removal: */
1550
1551static int bch2_dev_remove_alloc(struct bch_fs *c, struct bch_dev *ca)
1552{
1553	struct bpos start	= POS(ca->dev_idx, 0);
1554	struct bpos end		= POS(ca->dev_idx, U64_MAX);
1555	int ret;
1556
1557	/*
1558	 * We clear the LRU and need_discard btrees first so that we don't race
1559	 * with bch2_do_invalidates() and bch2_do_discards()
1560	 */
1561	ret =   bch2_btree_delete_range(c, BTREE_ID_lru, start, end,
1562					BTREE_TRIGGER_NORUN, NULL) ?:
1563		bch2_btree_delete_range(c, BTREE_ID_need_discard, start, end,
1564					BTREE_TRIGGER_NORUN, NULL) ?:
1565		bch2_btree_delete_range(c, BTREE_ID_freespace, start, end,
1566					BTREE_TRIGGER_NORUN, NULL) ?:
1567		bch2_btree_delete_range(c, BTREE_ID_backpointers, start, end,
1568					BTREE_TRIGGER_NORUN, NULL) ?:
1569		bch2_btree_delete_range(c, BTREE_ID_alloc, start, end,
1570					BTREE_TRIGGER_NORUN, NULL) ?:
1571		bch2_btree_delete_range(c, BTREE_ID_bucket_gens, start, end,
1572					BTREE_TRIGGER_NORUN, NULL);
1573	bch_err_msg(c, ret, "removing dev alloc info");
1574	return ret;
1575}
1576
1577int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
1578{
1579	struct bch_member *m;
1580	unsigned dev_idx = ca->dev_idx, data;
1581	int ret;
1582
1583	down_write(&c->state_lock);
1584
1585	/*
1586	 * We consume a reference to ca->ref, regardless of whether we succeed
1587	 * or fail:
1588	 */
1589	percpu_ref_put(&ca->ref);
1590
1591	if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1592		bch_err(ca, "Cannot remove without losing data");
1593		ret = -BCH_ERR_device_state_not_allowed;
1594		goto err;
1595	}
1596
1597	__bch2_dev_read_only(c, ca);
1598
1599	ret = bch2_dev_data_drop(c, ca->dev_idx, flags);
1600	bch_err_msg(ca, ret, "dropping data");
1601	if (ret)
1602		goto err;
1603
1604	ret = bch2_dev_remove_alloc(c, ca);
1605	bch_err_msg(ca, ret, "deleting alloc info");
1606	if (ret)
1607		goto err;
1608
1609	ret = bch2_journal_flush_device_pins(&c->journal, ca->dev_idx);
1610	bch_err_msg(ca, ret, "flushing journal");
1611	if (ret)
1612		goto err;
1613
1614	ret = bch2_journal_flush(&c->journal);
1615	bch_err(ca, "journal error");
1616	if (ret)
1617		goto err;
1618
1619	ret = bch2_replicas_gc2(c);
1620	bch_err_msg(ca, ret, "in replicas_gc2()");
1621	if (ret)
1622		goto err;
1623
1624	data = bch2_dev_has_data(c, ca);
1625	if (data) {
1626		struct printbuf data_has = PRINTBUF;
1627
1628		prt_bitflags(&data_has, __bch2_data_types, data);
1629		bch_err(ca, "Remove failed, still has data (%s)", data_has.buf);
1630		printbuf_exit(&data_has);
1631		ret = -EBUSY;
1632		goto err;
1633	}
1634
1635	__bch2_dev_offline(c, ca);
1636
1637	mutex_lock(&c->sb_lock);
1638	rcu_assign_pointer(c->devs[ca->dev_idx], NULL);
1639	mutex_unlock(&c->sb_lock);
1640
1641	percpu_ref_kill(&ca->ref);
1642	wait_for_completion(&ca->ref_completion);
1643
1644	bch2_dev_free(ca);
1645
1646	/*
1647	 * At this point the device object has been removed in-core, but the
1648	 * on-disk journal might still refer to the device index via sb device
1649	 * usage entries. Recovery fails if it sees usage information for an
1650	 * invalid device. Flush journal pins to push the back of the journal
1651	 * past now invalid device index references before we update the
1652	 * superblock, but after the device object has been removed so any
1653	 * further journal writes elide usage info for the device.
1654	 */
1655	bch2_journal_flush_all_pins(&c->journal);
1656
1657	/*
1658	 * Free this device's slot in the bch_member array - all pointers to
1659	 * this device must be gone:
1660	 */
1661	mutex_lock(&c->sb_lock);
1662	m = bch2_members_v2_get_mut(c->disk_sb.sb, dev_idx);
1663	memset(&m->uuid, 0, sizeof(m->uuid));
1664
1665	bch2_write_super(c);
1666
1667	mutex_unlock(&c->sb_lock);
1668	up_write(&c->state_lock);
1669
1670	bch2_dev_usage_journal_reserve(c);
1671	return 0;
1672err:
1673	if (ca->mi.state == BCH_MEMBER_STATE_rw &&
1674	    !percpu_ref_is_zero(&ca->io_ref))
1675		__bch2_dev_read_write(c, ca);
1676	up_write(&c->state_lock);
1677	return ret;
1678}
1679
1680/* Add new device to running filesystem: */
1681int bch2_dev_add(struct bch_fs *c, const char *path)
1682{
1683	struct bch_opts opts = bch2_opts_empty();
1684	struct bch_sb_handle sb;
1685	struct bch_dev *ca = NULL;
1686	struct bch_sb_field_members_v2 *mi;
1687	struct bch_member dev_mi;
1688	unsigned dev_idx, nr_devices, u64s;
1689	struct printbuf errbuf = PRINTBUF;
1690	struct printbuf label = PRINTBUF;
1691	int ret;
1692
1693	ret = bch2_read_super(path, &opts, &sb);
1694	bch_err_msg(c, ret, "reading super");
1695	if (ret)
1696		goto err;
1697
1698	dev_mi = bch2_sb_member_get(sb.sb, sb.sb->dev_idx);
1699
1700	if (BCH_MEMBER_GROUP(&dev_mi)) {
1701		bch2_disk_path_to_text_sb(&label, sb.sb, BCH_MEMBER_GROUP(&dev_mi) - 1);
1702		if (label.allocation_failure) {
1703			ret = -ENOMEM;
1704			goto err;
1705		}
1706	}
1707
1708	ret = bch2_dev_may_add(sb.sb, c);
1709	if (ret)
1710		goto err;
1711
1712	ca = __bch2_dev_alloc(c, &dev_mi);
1713	if (!ca) {
1714		ret = -ENOMEM;
1715		goto err;
1716	}
1717
1718	bch2_dev_usage_init(ca);
1719
1720	ret = __bch2_dev_attach_bdev(ca, &sb);
1721	if (ret)
1722		goto err;
1723
1724	ret = bch2_dev_journal_alloc(ca);
1725	bch_err_msg(c, ret, "allocating journal");
1726	if (ret)
1727		goto err;
1728
1729	down_write(&c->state_lock);
1730	mutex_lock(&c->sb_lock);
1731
1732	ret = bch2_sb_from_fs(c, ca);
1733	bch_err_msg(c, ret, "setting up new superblock");
1734	if (ret)
1735		goto err_unlock;
1736
1737	if (dynamic_fault("bcachefs:add:no_slot"))
1738		goto no_slot;
1739
1740	for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
1741		if (!bch2_dev_exists(c->disk_sb.sb, dev_idx))
1742			goto have_slot;
1743no_slot:
1744	ret = -BCH_ERR_ENOSPC_sb_members;
1745	bch_err_msg(c, ret, "setting up new superblock");
1746	goto err_unlock;
1747
1748have_slot:
1749	nr_devices = max_t(unsigned, dev_idx + 1, c->sb.nr_devices);
1750
1751	mi = bch2_sb_field_get(c->disk_sb.sb, members_v2);
1752	u64s = DIV_ROUND_UP(sizeof(struct bch_sb_field_members_v2) +
1753			    le16_to_cpu(mi->member_bytes) * nr_devices, sizeof(u64));
1754
1755	mi = bch2_sb_field_resize(&c->disk_sb, members_v2, u64s);
1756	if (!mi) {
1757		ret = -BCH_ERR_ENOSPC_sb_members;
1758		bch_err_msg(c, ret, "setting up new superblock");
1759		goto err_unlock;
1760	}
1761	struct bch_member *m = bch2_members_v2_get_mut(c->disk_sb.sb, dev_idx);
1762
1763	/* success: */
1764
1765	*m = dev_mi;
1766	m->last_mount = cpu_to_le64(ktime_get_real_seconds());
1767	c->disk_sb.sb->nr_devices	= nr_devices;
1768
1769	ca->disk_sb.sb->dev_idx	= dev_idx;
1770	bch2_dev_attach(c, ca, dev_idx);
1771
1772	if (BCH_MEMBER_GROUP(&dev_mi)) {
1773		ret = __bch2_dev_group_set(c, ca, label.buf);
1774		bch_err_msg(c, ret, "creating new label");
1775		if (ret)
1776			goto err_unlock;
1777	}
1778
1779	bch2_write_super(c);
1780	mutex_unlock(&c->sb_lock);
1781
1782	bch2_dev_usage_journal_reserve(c);
1783
1784	ret = bch2_trans_mark_dev_sb(c, ca);
1785	bch_err_msg(ca, ret, "marking new superblock");
1786	if (ret)
1787		goto err_late;
1788
1789	ret = bch2_fs_freespace_init(c);
1790	bch_err_msg(ca, ret, "initializing free space");
1791	if (ret)
1792		goto err_late;
1793
1794	ca->new_fs_bucket_idx = 0;
1795
1796	if (ca->mi.state == BCH_MEMBER_STATE_rw)
1797		__bch2_dev_read_write(c, ca);
1798
1799	up_write(&c->state_lock);
1800	return 0;
1801
1802err_unlock:
1803	mutex_unlock(&c->sb_lock);
1804	up_write(&c->state_lock);
1805err:
1806	if (ca)
1807		bch2_dev_free(ca);
1808	bch2_free_super(&sb);
1809	printbuf_exit(&label);
1810	printbuf_exit(&errbuf);
1811	bch_err_fn(c, ret);
1812	return ret;
1813err_late:
1814	up_write(&c->state_lock);
1815	ca = NULL;
1816	goto err;
1817}
1818
1819/* Hot add existing device to running filesystem: */
1820int bch2_dev_online(struct bch_fs *c, const char *path)
1821{
1822	struct bch_opts opts = bch2_opts_empty();
1823	struct bch_sb_handle sb = { NULL };
1824	struct bch_dev *ca;
1825	unsigned dev_idx;
1826	int ret;
1827
1828	down_write(&c->state_lock);
1829
1830	ret = bch2_read_super(path, &opts, &sb);
1831	if (ret) {
1832		up_write(&c->state_lock);
1833		return ret;
1834	}
1835
1836	dev_idx = sb.sb->dev_idx;
1837
1838	ret = bch2_dev_in_fs(&c->disk_sb, &sb);
1839	bch_err_msg(c, ret, "bringing %s online", path);
1840	if (ret)
1841		goto err;
1842
1843	ret = bch2_dev_attach_bdev(c, &sb);
1844	if (ret)
1845		goto err;
1846
1847	ca = bch_dev_locked(c, dev_idx);
1848
1849	ret = bch2_trans_mark_dev_sb(c, ca);
1850	bch_err_msg(c, ret, "bringing %s online: error from bch2_trans_mark_dev_sb", path);
1851	if (ret)
1852		goto err;
1853
1854	if (ca->mi.state == BCH_MEMBER_STATE_rw)
1855		__bch2_dev_read_write(c, ca);
1856
1857	if (!ca->mi.freespace_initialized) {
1858		ret = bch2_dev_freespace_init(c, ca, 0, ca->mi.nbuckets);
1859		bch_err_msg(ca, ret, "initializing free space");
1860		if (ret)
1861			goto err;
1862	}
1863
1864	if (!ca->journal.nr) {
1865		ret = bch2_dev_journal_alloc(ca);
1866		bch_err_msg(ca, ret, "allocating journal");
1867		if (ret)
1868			goto err;
1869	}
1870
1871	mutex_lock(&c->sb_lock);
1872	bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx)->last_mount =
1873		cpu_to_le64(ktime_get_real_seconds());
1874	bch2_write_super(c);
1875	mutex_unlock(&c->sb_lock);
1876
1877	up_write(&c->state_lock);
1878	return 0;
1879err:
1880	up_write(&c->state_lock);
1881	bch2_free_super(&sb);
1882	return ret;
1883}
1884
1885int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
1886{
1887	down_write(&c->state_lock);
1888
1889	if (!bch2_dev_is_online(ca)) {
1890		bch_err(ca, "Already offline");
1891		up_write(&c->state_lock);
1892		return 0;
1893	}
1894
1895	if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
1896		bch_err(ca, "Cannot offline required disk");
1897		up_write(&c->state_lock);
1898		return -BCH_ERR_device_state_not_allowed;
1899	}
1900
1901	__bch2_dev_offline(c, ca);
1902
1903	up_write(&c->state_lock);
1904	return 0;
1905}
1906
1907int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
1908{
1909	struct bch_member *m;
1910	u64 old_nbuckets;
1911	int ret = 0;
1912
1913	down_write(&c->state_lock);
1914	old_nbuckets = ca->mi.nbuckets;
1915
1916	if (nbuckets < ca->mi.nbuckets) {
1917		bch_err(ca, "Cannot shrink yet");
1918		ret = -EINVAL;
1919		goto err;
1920	}
1921
1922	if (bch2_dev_is_online(ca) &&
1923	    get_capacity(ca->disk_sb.bdev->bd_disk) <
1924	    ca->mi.bucket_size * nbuckets) {
1925		bch_err(ca, "New size larger than device");
1926		ret = -BCH_ERR_device_size_too_small;
1927		goto err;
1928	}
1929
1930	ret = bch2_dev_buckets_resize(c, ca, nbuckets);
1931	bch_err_msg(ca, ret, "resizing buckets");
1932	if (ret)
1933		goto err;
1934
1935	ret = bch2_trans_mark_dev_sb(c, ca);
1936	if (ret)
1937		goto err;
1938
1939	mutex_lock(&c->sb_lock);
1940	m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
1941	m->nbuckets = cpu_to_le64(nbuckets);
1942
1943	bch2_write_super(c);
1944	mutex_unlock(&c->sb_lock);
1945
1946	if (ca->mi.freespace_initialized) {
1947		ret = bch2_dev_freespace_init(c, ca, old_nbuckets, nbuckets);
1948		if (ret)
1949			goto err;
1950
1951		/*
1952		 * XXX: this is all wrong transactionally - we'll be able to do
1953		 * this correctly after the disk space accounting rewrite
1954		 */
1955		ca->usage_base->d[BCH_DATA_free].buckets += nbuckets - old_nbuckets;
1956	}
1957
1958	bch2_recalc_capacity(c);
1959err:
1960	up_write(&c->state_lock);
1961	return ret;
1962}
1963
1964/* return with ref on ca->ref: */
1965struct bch_dev *bch2_dev_lookup(struct bch_fs *c, const char *name)
1966{
1967	rcu_read_lock();
1968	for_each_member_device_rcu(c, ca, NULL)
1969		if (!strcmp(name, ca->name)) {
1970			rcu_read_unlock();
1971			return ca;
1972		}
1973	rcu_read_unlock();
1974	return ERR_PTR(-BCH_ERR_ENOENT_dev_not_found);
1975}
1976
1977/* Filesystem open: */
1978
1979static inline int sb_cmp(struct bch_sb *l, struct bch_sb *r)
1980{
1981	return  cmp_int(le64_to_cpu(l->seq), le64_to_cpu(r->seq)) ?:
1982		cmp_int(le64_to_cpu(l->write_time), le64_to_cpu(r->write_time));
1983}
1984
1985struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
1986			    struct bch_opts opts)
1987{
1988	DARRAY(struct bch_sb_handle) sbs = { 0 };
1989	struct bch_fs *c = NULL;
1990	struct bch_sb_handle *best = NULL;
1991	struct printbuf errbuf = PRINTBUF;
1992	int ret = 0;
1993
1994	if (!try_module_get(THIS_MODULE))
1995		return ERR_PTR(-ENODEV);
1996
1997	if (!nr_devices) {
1998		ret = -EINVAL;
1999		goto err;
2000	}
2001
2002	ret = darray_make_room(&sbs, nr_devices);
2003	if (ret)
2004		goto err;
2005
2006	for (unsigned i = 0; i < nr_devices; i++) {
2007		struct bch_sb_handle sb = { NULL };
2008
2009		ret = bch2_read_super(devices[i], &opts, &sb);
2010		if (ret)
2011			goto err;
2012
2013		BUG_ON(darray_push(&sbs, sb));
2014	}
2015
2016	if (opts.nochanges && !opts.read_only) {
2017		ret = -BCH_ERR_erofs_nochanges;
2018		goto err_print;
2019	}
2020
2021	darray_for_each(sbs, sb)
2022		if (!best || sb_cmp(sb->sb, best->sb) > 0)
2023			best = sb;
2024
2025	darray_for_each_reverse(sbs, sb) {
2026		ret = bch2_dev_in_fs(best, sb);
2027
2028		if (ret == -BCH_ERR_device_has_been_removed ||
2029		    ret == -BCH_ERR_device_splitbrain) {
2030			bch2_free_super(sb);
2031			darray_remove_item(&sbs, sb);
2032			best -= best > sb;
2033			ret = 0;
2034			continue;
2035		}
2036
2037		if (ret)
2038			goto err_print;
2039	}
2040
2041	c = bch2_fs_alloc(best->sb, opts);
2042	ret = PTR_ERR_OR_ZERO(c);
2043	if (ret)
2044		goto err;
2045
2046	down_write(&c->state_lock);
2047	darray_for_each(sbs, sb) {
2048		ret = bch2_dev_attach_bdev(c, sb);
2049		if (ret) {
2050			up_write(&c->state_lock);
2051			goto err;
2052		}
2053	}
2054	up_write(&c->state_lock);
2055
2056	if (!bch2_fs_may_start(c)) {
2057		ret = -BCH_ERR_insufficient_devices_to_start;
2058		goto err_print;
2059	}
2060
2061	if (!c->opts.nostart) {
2062		ret = bch2_fs_start(c);
2063		if (ret)
2064			goto err;
2065	}
2066out:
2067	darray_for_each(sbs, sb)
2068		bch2_free_super(sb);
2069	darray_exit(&sbs);
2070	printbuf_exit(&errbuf);
2071	module_put(THIS_MODULE);
2072	return c;
2073err_print:
2074	pr_err("bch_fs_open err opening %s: %s",
2075	       devices[0], bch2_err_str(ret));
2076err:
2077	if (!IS_ERR_OR_NULL(c))
2078		bch2_fs_stop(c);
2079	c = ERR_PTR(ret);
2080	goto out;
2081}
2082
2083/* Global interfaces/init */
2084
2085static void bcachefs_exit(void)
2086{
2087	bch2_debug_exit();
2088	bch2_vfs_exit();
2089	bch2_chardev_exit();
2090	bch2_btree_key_cache_exit();
2091	if (bcachefs_kset)
2092		kset_unregister(bcachefs_kset);
2093}
2094
2095static int __init bcachefs_init(void)
2096{
2097	bch2_bkey_pack_test();
2098
2099	if (!(bcachefs_kset = kset_create_and_add("bcachefs", NULL, fs_kobj)) ||
2100	    bch2_btree_key_cache_init() ||
2101	    bch2_chardev_init() ||
2102	    bch2_vfs_init() ||
2103	    bch2_debug_init())
2104		goto err;
2105
2106	return 0;
2107err:
2108	bcachefs_exit();
2109	return -ENOMEM;
2110}
2111
2112#define BCH_DEBUG_PARAM(name, description)			\
2113	bool bch2_##name;					\
2114	module_param_named(name, bch2_##name, bool, 0644);	\
2115	MODULE_PARM_DESC(name, description);
2116BCH_DEBUG_PARAMS()
2117#undef BCH_DEBUG_PARAM
2118
2119__maybe_unused
2120static unsigned bch2_metadata_version = bcachefs_metadata_version_current;
2121module_param_named(version, bch2_metadata_version, uint, 0400);
2122
2123module_exit(bcachefs_exit);
2124module_init(bcachefs_init);