]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/super.c
Update bcachefs sources to fd6fb298aa bcachefs: Make sure hash info gets initialized...
[bcachefs-tools-debian] / libbcachefs / super.c
index 71fc231d380c190b41b2ea6135c594cc517a7f6a..066a72a2f57261ff5f003c2b0929708f6c1ea1cb 100644 (file)
@@ -16,6 +16,7 @@
 #include "btree_key_cache.h"
 #include "btree_update_interior.h"
 #include "btree_io.h"
+#include "btree_write_buffer.h"
 #include "buckets_waiting_for_journal.h"
 #include "chardev.h"
 #include "checksum.h"
@@ -24,6 +25,7 @@
 #include "debug.h"
 #include "disk_groups.h"
 #include "ec.h"
+#include "errcode.h"
 #include "error.h"
 #include "fs.h"
 #include "fs-io.h"
@@ -36,6 +38,7 @@
 #include "move.h"
 #include "migrate.h"
 #include "movinggc.h"
+#include "nocow_locking.h"
 #include "quota.h"
 #include "rebalance.h"
 #include "recovery.h"
@@ -53,7 +56,6 @@
 #include <linux/idr.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
-#include <linux/pretty-printers.h>
 #include <linux/random.h>
 #include <linux/sysfs.h>
 #include <crypto/hash.h>
@@ -108,7 +110,7 @@ static struct kset *bcachefs_kset;
 static LIST_HEAD(bch_fs_list);
 static DEFINE_MUTEX(bch_fs_list_lock);
 
-static DECLARE_WAIT_QUEUE_HEAD(bch_read_only_wait);
+DECLARE_WAIT_QUEUE_HEAD(bch2_read_only_wait);
 
 static void bch2_dev_free(struct bch_dev *);
 static int bch2_dev_alloc(struct bch_fs *, unsigned);
@@ -204,11 +206,15 @@ static void __bch2_fs_read_only(struct bch_fs *c)
        unsigned i, clean_passes = 0;
        u64 seq = 0;
 
+       bch2_fs_ec_stop(c);
+       bch2_open_buckets_stop(c, NULL, true);
        bch2_rebalance_stop(c);
        bch2_copygc_stop(c);
        bch2_gc_thread_stop(c);
+       bch2_fs_ec_flush(c);
 
-       bch_verbose(c, "flushing journal and stopping allocators");
+       bch_verbose(c, "flushing journal and stopping allocators, journal seq %llu",
+                   journal_cur_seq(&c->journal));
 
        do {
                clean_passes++;
@@ -222,7 +228,8 @@ static void __bch2_fs_read_only(struct bch_fs *c)
                }
        } while (clean_passes < 2);
 
-       bch_verbose(c, "flushing journal and stopping allocators complete");
+       bch_verbose(c, "flushing journal and stopping allocators complete, journal seq %llu",
+                   journal_cur_seq(&c->journal));
 
        if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
            !test_bit(BCH_FS_EMERGENCY_RO, &c->flags))
@@ -236,13 +243,15 @@ static void __bch2_fs_read_only(struct bch_fs *c)
                bch2_dev_allocator_remove(c, ca);
 }
 
+#ifndef BCH_WRITE_REF_DEBUG
 static void bch2_writes_disabled(struct percpu_ref *writes)
 {
        struct bch_fs *c = container_of(writes, struct bch_fs, writes);
 
        set_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
-       wake_up(&bch_read_only_wait);
+       wake_up(&bch2_read_only_wait);
 }
+#endif
 
 void bch2_fs_read_only(struct bch_fs *c)
 {
@@ -257,9 +266,13 @@ void bch2_fs_read_only(struct bch_fs *c)
         * Block new foreground-end write operations from starting - any new
         * writes will return -EROFS:
         */
+       set_bit(BCH_FS_GOING_RO, &c->flags);
+#ifndef BCH_WRITE_REF_DEBUG
        percpu_ref_kill(&c->writes);
-
-       cancel_work_sync(&c->ec_stripe_delete_work);
+#else
+       for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++)
+               bch2_write_ref_put(c, i);
+#endif
 
        /*
         * If we're not doing an emergency shutdown, we want to wait on
@@ -272,16 +285,17 @@ void bch2_fs_read_only(struct bch_fs *c)
         * we do need to wait on them before returning and signalling
         * that going RO is complete:
         */
-       wait_event(bch_read_only_wait,
+       wait_event(bch2_read_only_wait,
                   test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags) ||
                   test_bit(BCH_FS_EMERGENCY_RO, &c->flags));
 
        __bch2_fs_read_only(c);
 
-       wait_event(bch_read_only_wait,
+       wait_event(bch2_read_only_wait,
                   test_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags));
 
        clear_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags);
+       clear_bit(BCH_FS_GOING_RO, &c->flags);
 
        if (!bch2_journal_error(&c->journal) &&
            !test_bit(BCH_FS_ERROR, &c->flags) &&
@@ -318,7 +332,7 @@ bool bch2_fs_emergency_read_only(struct bch_fs *c)
        bch2_journal_halt(&c->journal);
        bch2_fs_read_only_async(c);
 
-       wake_up(&bch_read_only_wait);
+       wake_up(&bch2_read_only_wait);
        return ret;
 }
 
@@ -326,26 +340,12 @@ static int bch2_fs_read_write_late(struct bch_fs *c)
 {
        int ret;
 
-       ret = bch2_gc_thread_start(c);
-       if (ret) {
-               bch_err(c, "error starting gc thread");
-               return ret;
-       }
-
-       ret = bch2_copygc_start(c);
-       if (ret) {
-               bch_err(c, "error starting copygc thread");
-               return ret;
-       }
-
        ret = bch2_rebalance_start(c);
        if (ret) {
                bch_err(c, "error starting rebalance thread");
                return ret;
        }
 
-       schedule_work(&c->ec_stripe_delete_work);
-
        return 0;
 }
 
@@ -380,12 +380,29 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 
        clear_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags);
 
+       /*
+        * First journal write must be a flush write: after a clean shutdown we
+        * don't read the journal, so the first journal write may end up
+        * overwriting whatever was there previously, and there must always be
+        * at least one non-flush write in the journal or recovery will fail:
+        */
+       set_bit(JOURNAL_NEED_FLUSH_WRITE, &c->journal.flags);
+
        for_each_rw_member(ca, c, i)
                bch2_dev_allocator_add(c, ca);
        bch2_recalc_capacity(c);
 
-       bch2_do_discards(c);
-       bch2_do_invalidates(c);
+       ret = bch2_gc_thread_start(c);
+       if (ret) {
+               bch_err(c, "error starting gc thread");
+               return ret;
+       }
+
+       ret = bch2_copygc_start(c);
+       if (ret) {
+               bch_err(c, "error starting copygc thread");
+               return ret;
+       }
 
        if (!early) {
                ret = bch2_fs_read_write_late(c);
@@ -393,9 +410,21 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
                        goto err;
        }
 
+#ifndef BCH_WRITE_REF_DEBUG
        percpu_ref_reinit(&c->writes);
+#else
+       for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) {
+               BUG_ON(atomic_long_read(&c->writes[i]));
+               atomic_long_inc(&c->writes[i]);
+       }
+#endif
        set_bit(BCH_FS_RW, &c->flags);
        set_bit(BCH_FS_WAS_RW, &c->flags);
+
+       bch2_do_discards(c);
+       bch2_do_invalidates(c);
+       bch2_do_stripe_deletes(c);
+       bch2_do_pending_node_rewrites(c);
        return 0;
 err:
        __bch2_fs_read_only(c);
@@ -424,6 +453,7 @@ static void __bch2_fs_free(struct bch_fs *c)
        for (i = 0; i < BCH_TIME_STAT_NR; i++)
                bch2_time_stats_exit(&c->times[i]);
 
+       bch2_free_pending_node_rewrites(c);
        bch2_fs_counters_exit(c);
        bch2_fs_snapshots_exit(c);
        bch2_fs_quota_exit(c);
@@ -443,27 +473,31 @@ static void __bch2_fs_free(struct bch_fs *c)
        bch2_fs_compress_exit(c);
        bch2_journal_keys_free(&c->journal_keys);
        bch2_journal_entries_free(c);
+       bch2_fs_btree_write_buffer_exit(c);
        percpu_free_rwsem(&c->mark_lock);
+       free_percpu(c->online_reserved);
 
        if (c->btree_paths_bufs)
                for_each_possible_cpu(cpu)
                        kfree(per_cpu_ptr(c->btree_paths_bufs, cpu)->path);
 
-       free_percpu(c->online_reserved);
        free_percpu(c->btree_paths_bufs);
        free_percpu(c->pcpu);
        mempool_exit(&c->large_bkey_pool);
        mempool_exit(&c->btree_bounce_pool);
        bioset_exit(&c->btree_bio);
        mempool_exit(&c->fill_iter);
+#ifndef BCH_WRITE_REF_DEBUG
        percpu_ref_exit(&c->writes);
+#endif
        kfree(rcu_dereference_protected(c->disk_groups, 1));
        kfree(c->journal_seq_blacklist_table);
        kfree(c->unused_inode_hints);
-       free_heap(&c->copygc_heap);
 
-       if (c->io_complete_wq )
-               destroy_workqueue(c->io_complete_wq );
+       if (c->write_ref_wq)
+               destroy_workqueue(c->write_ref_wq);
+       if (c->io_complete_wq)
+               destroy_workqueue(c->io_complete_wq);
        if (c->copygc_wq)
                destroy_workqueue(c->copygc_wq);
        if (c->btree_io_complete_wq)
@@ -615,7 +649,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 
        c = kvpmalloc(sizeof(struct bch_fs), GFP_KERNEL|__GFP_ZERO);
        if (!c) {
-               c = ERR_PTR(-ENOMEM);
+               c = ERR_PTR(-BCH_ERR_ENOMEM_fs_alloc);
                goto out;
        }
 
@@ -652,6 +686,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
        bch2_fs_rebalance_init(c);
        bch2_fs_quota_init(c);
        bch2_fs_ec_init_early(c);
+       bch2_fs_move_init(c);
 
        INIT_LIST_HEAD(&c->list);
 
@@ -670,22 +705,14 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
        INIT_LIST_HEAD(&c->fsck_errors);
        mutex_init(&c->fsck_error_lock);
 
-       INIT_LIST_HEAD(&c->ec_stripe_head_list);
-       mutex_init(&c->ec_stripe_head_lock);
-
-       INIT_LIST_HEAD(&c->ec_stripe_new_list);
-       mutex_init(&c->ec_stripe_new_lock);
-
-       INIT_LIST_HEAD(&c->data_progress_list);
-       mutex_init(&c->data_progress_lock);
-
-       spin_lock_init(&c->ec_stripes_heap_lock);
-
        seqcount_init(&c->gc_pos_lock);
 
        seqcount_init(&c->usage_lock);
 
-       sema_init(&c->io_in_flight, 64);
+       sema_init(&c->io_in_flight, 128);
+
+       INIT_LIST_HEAD(&c->vfs_inodes_list);
+       mutex_init(&c->vfs_inodes_lock);
 
        c->copy_gc_enabled              = 1;
        c->rebalance.enabled            = 1;
@@ -712,10 +739,10 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
                goto err;
 
        pr_uuid(&name, c->sb.user_uuid.b);
-       strlcpy(c->name, name.buf, sizeof(c->name));
+       strscpy(c->name, name.buf, sizeof(c->name));
        printbuf_exit(&name);
 
-       ret = name.allocation_failure ? -ENOMEM : 0;
+       ret = name.allocation_failure ? -BCH_ERR_ENOMEM_fs_name_alloc : 0;
        if (ret)
                goto err;
 
@@ -735,9 +762,6 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 
        bch2_opts_apply(&c->opts, opts);
 
-       /* key cache currently disabled for inodes, because of snapshots: */
-       c->opts.inodes_use_key_cache = 0;
-
        c->btree_key_cache_btrees |= 1U << BTREE_ID_alloc;
        if (c->opts.inodes_use_key_cache)
                c->btree_key_cache_btrees |= 1U << BTREE_ID_inodes;
@@ -758,33 +782,38 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
        c->inode_shard_bits = ilog2(roundup_pow_of_two(num_possible_cpus()));
 
        if (!(c->btree_update_wq = alloc_workqueue("bcachefs",
-                               WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
+                               WQ_FREEZABLE|WQ_UNBOUND|WQ_MEM_RECLAIM, 512)) ||
            !(c->btree_io_complete_wq = alloc_workqueue("bcachefs_btree_io",
-                               WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
+                               WQ_FREEZABLE|WQ_MEM_RECLAIM, 1)) ||
            !(c->copygc_wq = alloc_workqueue("bcachefs_copygc",
                                WQ_FREEZABLE|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 1)) ||
            !(c->io_complete_wq = alloc_workqueue("bcachefs_io",
                                WQ_FREEZABLE|WQ_HIGHPRI|WQ_MEM_RECLAIM, 1)) ||
+           !(c->write_ref_wq = alloc_workqueue("bcachefs_write_ref",
+                               WQ_FREEZABLE, 0)) ||
+#ifndef BCH_WRITE_REF_DEBUG
            percpu_ref_init(&c->writes, bch2_writes_disabled,
                            PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
+#endif
            mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
            bioset_init(&c->btree_bio, 1,
                        max(offsetof(struct btree_read_bio, bio),
                            offsetof(struct btree_write_bio, wbio.bio)),
                        BIOSET_NEED_BVECS) ||
            !(c->pcpu = alloc_percpu(struct bch_fs_pcpu)) ||
-           !(c->btree_paths_bufs = alloc_percpu(struct btree_path_buf)) ||
            !(c->online_reserved = alloc_percpu(u64)) ||
+           !(c->btree_paths_bufs = alloc_percpu(struct btree_path_buf)) ||
            mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
                                        btree_bytes(c)) ||
            mempool_init_kmalloc_pool(&c->large_bkey_pool, 1, 2048) ||
            !(c->unused_inode_hints = kcalloc(1U << c->inode_shard_bits,
                                              sizeof(u64), GFP_KERNEL))) {
-               ret = -ENOMEM;
+               ret = -BCH_ERR_ENOMEM_fs_other_alloc;
                goto err;
        }
 
-       ret = bch2_io_clock_init(&c->io_clock[READ]) ?:
+       ret = bch2_fs_counters_init(c) ?:
+           bch2_io_clock_init(&c->io_clock[READ]) ?:
            bch2_io_clock_init(&c->io_clock[WRITE]) ?:
            bch2_fs_journal_init(&c->journal) ?:
            bch2_fs_replicas_init(c) ?:
@@ -793,13 +822,14 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
            bch2_fs_btree_iter_init(c) ?:
            bch2_fs_btree_interior_update_init(c) ?:
            bch2_fs_buckets_waiting_for_journal_init(c) ?:
+           bch2_fs_btree_write_buffer_init(c) ?:
            bch2_fs_subvolumes_init(c) ?:
            bch2_fs_io_init(c) ?:
+           bch2_fs_nocow_locking_init(c) ?:
            bch2_fs_encryption_init(c) ?:
            bch2_fs_compress_init(c) ?:
            bch2_fs_ec_init(c) ?:
-           bch2_fs_fsio_init(c) ?:
-           bch2_fs_counters_init(c);
+           bch2_fs_fsio_init(c);
        if (ret)
                goto err;
 
@@ -841,9 +871,12 @@ static void print_mount_opts(struct bch_fs *c)
        struct printbuf p = PRINTBUF;
        bool first = true;
 
+       prt_printf(&p, "mounted version=%s", bch2_metadata_versions[c->sb.version]);
+
        if (c->opts.read_only) {
-               prt_printf(&p, "ro");
+               prt_str(&p, " opts=");
                first = false;
+               prt_printf(&p, "ro");
        }
 
        for (i = 0; i < bch2_opts_nr; i++) {
@@ -856,16 +889,12 @@ static void print_mount_opts(struct bch_fs *c)
                if (v == bch2_opt_get_by_id(&bch2_opts_default, i))
                        continue;
 
-               if (!first)
-                       prt_printf(&p, ",");
+               prt_str(&p, first ? " opts=" : ",");
                first = false;
                bch2_opt_to_text(&p, c, c->disk_sb.sb, opt, v, OPT_SHOW_MOUNT_STYLE);
        }
 
-       if (!p.pos)
-               prt_printf(&p, "(null)");
-
-       bch_info(c, "mounted version=%s opts=%s", bch2_metadata_versions[c->sb.version], p.buf);
+       bch_info(c, "%s", p.buf);
        printbuf_exit(&p);
 }
 
@@ -875,7 +904,7 @@ int bch2_fs_start(struct bch_fs *c)
        struct bch_dev *ca;
        time64_t now = ktime_get_real_seconds();
        unsigned i;
-       int ret = -EINVAL;
+       int ret;
 
        down_write(&c->state_lock);
 
@@ -896,6 +925,12 @@ int bch2_fs_start(struct bch_fs *c)
                bch2_dev_allocator_add(c, ca);
        bch2_recalc_capacity(c);
 
+       for (i = 0; i < BCH_TRANSACTIONS_NR; i++) {
+               mutex_lock(&c->btree_transaction_stats[i].lock);
+               bch2_time_stats_init(&c->btree_transaction_stats[i].lock_hold_times);
+               mutex_unlock(&c->btree_transaction_stats[i].lock);
+       }
+
        ret = BCH_SB_INITIALIZED(c->disk_sb.sb)
                ? bch2_fs_recovery(c)
                : bch2_fs_initialize(c);
@@ -906,9 +941,9 @@ int bch2_fs_start(struct bch_fs *c)
        if (ret)
                goto err;
 
-       ret = -EINVAL;
        if (bch2_fs_init_fault("fs_start")) {
                bch_err(c, "fs_start fault injected");
+               ret = -EINVAL;
                goto err;
        }
 
@@ -930,68 +965,44 @@ out:
        up_write(&c->state_lock);
        return ret;
 err:
-       switch (ret) {
-       case BCH_FSCK_ERRORS_NOT_FIXED:
-               bch_err(c, "filesystem contains errors: please report this to the developers");
-               pr_cont("mount with -o fix_errors to repair\n");
-               break;
-       case BCH_FSCK_REPAIR_UNIMPLEMENTED:
-               bch_err(c, "filesystem contains errors: please report this to the developers");
-               pr_cont("repair unimplemented: inform the developers so that it can be added\n");
-               break;
-       case BCH_FSCK_REPAIR_IMPOSSIBLE:
-               bch_err(c, "filesystem contains errors, but repair impossible");
-               break;
-       case BCH_FSCK_UNKNOWN_VERSION:
-               bch_err(c, "unknown metadata version");
-               break;
-       case -ENOMEM:
-               bch_err(c, "cannot allocate memory");
-               break;
-       case -EIO:
-               bch_err(c, "IO error");
-               break;
-       }
-
-       if (ret >= 0)
-               ret = -EIO;
+       bch_err(c, "error starting filesystem: %s", bch2_err_str(ret));
        goto out;
 }
 
-static const char *bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
+static int bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
 {
        struct bch_sb_field_members *sb_mi;
 
        sb_mi = bch2_sb_get_members(sb);
        if (!sb_mi)
-               return "Invalid superblock: member info area missing";
+               return -BCH_ERR_member_info_missing;
 
        if (le16_to_cpu(sb->block_size) != block_sectors(c))
-               return "mismatched block size";
+               return -BCH_ERR_mismatched_block_size;
 
        if (le16_to_cpu(sb_mi->members[sb->dev_idx].bucket_size) <
            BCH_SB_BTREE_NODE_SIZE(c->disk_sb.sb))
-               return "new cache bucket size is too small";
+               return -BCH_ERR_bucket_size_too_small;
 
-       return NULL;
+       return 0;
 }
 
-static const char *bch2_dev_in_fs(struct bch_sb *fs, struct bch_sb *sb)
+static int bch2_dev_in_fs(struct bch_sb *fs, struct bch_sb *sb)
 {
        struct bch_sb *newest =
                le64_to_cpu(fs->seq) > le64_to_cpu(sb->seq) ? fs : sb;
        struct bch_sb_field_members *mi = bch2_sb_get_members(newest);
 
        if (uuid_le_cmp(fs->uuid, sb->uuid))
-               return "device not a member of filesystem";
+               return -BCH_ERR_device_not_a_member_of_filesystem;
 
        if (!bch2_dev_exists(newest, mi, sb->dev_idx))
-               return "device has been removed";
+               return -BCH_ERR_device_has_been_removed;
 
        if (fs->block_size != sb->block_size)
-               return "mismatched block size";
+               return -BCH_ERR_mismatched_block_size;
 
-       return NULL;
+       return 0;
 }
 
 /* Device startup/shutdown: */
@@ -1178,7 +1189,7 @@ out:
 err:
        if (ca)
                bch2_dev_free(ca);
-       ret = -ENOMEM;
+       ret = -BCH_ERR_ENOMEM_dev_alloc;
        goto out;
 }
 
@@ -1189,23 +1200,17 @@ static int __bch2_dev_attach_bdev(struct bch_dev *ca, struct bch_sb_handle *sb)
        if (bch2_dev_is_online(ca)) {
                bch_err(ca, "already have device online in slot %u",
                        sb->sb->dev_idx);
-               return -EINVAL;
+               return -BCH_ERR_device_already_online;
        }
 
        if (get_capacity(sb->bdev->bd_disk) <
            ca->mi.bucket_size * ca->mi.nbuckets) {
                bch_err(ca, "cannot online: device too small");
-               return -EINVAL;
+               return -BCH_ERR_device_size_too_small;
        }
 
        BUG_ON(!percpu_ref_is_zero(&ca->io_ref));
 
-       if (get_capacity(sb->bdev->bd_disk) <
-           ca->mi.bucket_size * ca->mi.nbuckets) {
-               bch_err(ca, "device too small");
-               return -EINVAL;
-       }
-
        ret = bch2_dev_journal_init(ca, sb->sb);
        if (ret)
                return ret;
@@ -1246,8 +1251,8 @@ static int bch2_dev_attach_bdev(struct bch_fs *c, struct bch_sb_handle *sb)
        bch2_dev_sysfs_online(c, ca);
 
        if (c->sb.nr_devices == 1)
-               bdevname(ca->disk_sb.bdev, c->name);
-       bdevname(ca->disk_sb.bdev, ca->name);
+               snprintf(c->name, sizeof(c->name), "%pg", ca->disk_sb.bdev);
+       snprintf(ca->name, sizeof(ca->name), "%pg", ca->disk_sb.bdev);
 
        rebalance_wakeup(c);
        return 0;
@@ -1347,19 +1352,11 @@ static bool bch2_fs_may_start(struct bch_fs *c)
 
 static void __bch2_dev_read_only(struct bch_fs *c, struct bch_dev *ca)
 {
-       /*
-        * Device going read only means the copygc reserve get smaller, so we
-        * don't want that happening while copygc is in progress:
-        */
-       bch2_copygc_stop(c);
-
        /*
         * The allocator thread itself allocates btree nodes, so stop it first:
         */
        bch2_dev_allocator_remove(c, ca);
        bch2_dev_journal_stop(&c->journal, ca);
-
-       bch2_copygc_start(c);
 }
 
 static void __bch2_dev_read_write(struct bch_fs *c, struct bch_dev *ca)
@@ -1382,7 +1379,7 @@ int __bch2_dev_set_state(struct bch_fs *c, struct bch_dev *ca,
                return 0;
 
        if (!bch2_dev_state_allowed(c, ca, new_state, flags))
-               return -EINVAL;
+               return -BCH_ERR_device_state_not_allowed;
 
        if (new_state != BCH_MEMBER_STATE_rw)
                __bch2_dev_read_only(c, ca);
@@ -1433,10 +1430,14 @@ static int bch2_dev_remove_alloc(struct bch_fs *c, struct bch_dev *ca)
                                        BTREE_TRIGGER_NORUN, NULL) ?:
                bch2_btree_delete_range(c, BTREE_ID_freespace, start, end,
                                        BTREE_TRIGGER_NORUN, NULL) ?:
+               bch2_btree_delete_range(c, BTREE_ID_backpointers, start, end,
+                                       BTREE_TRIGGER_NORUN, NULL) ?:
                bch2_btree_delete_range(c, BTREE_ID_alloc, start, end,
+                                       BTREE_TRIGGER_NORUN, NULL) ?:
+               bch2_btree_delete_range(c, BTREE_ID_bucket_gens, start, end,
                                        BTREE_TRIGGER_NORUN, NULL);
        if (ret)
-               bch_err(c, "error %i removing dev alloc info", ret);
+               bch_err(c, "error removing dev alloc info: %s", bch2_err_str(ret));
 
        return ret;
 }
@@ -1445,7 +1446,7 @@ int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
 {
        struct bch_sb_field_members *mi;
        unsigned dev_idx = ca->dev_idx, data;
-       int ret = -EINVAL;
+       int ret;
 
        down_write(&c->state_lock);
 
@@ -1457,6 +1458,7 @@ int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
 
        if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
                bch_err(ca, "Cannot remove without losing data");
+               ret = -BCH_ERR_device_state_not_allowed;
                goto err;
        }
 
@@ -1464,7 +1466,7 @@ int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
 
        ret = bch2_dev_data_drop(c, ca->dev_idx, flags);
        if (ret) {
-               bch_err(ca, "Remove failed: error %i dropping data", ret);
+               bch_err(ca, "Remove failed: error dropping data: %s", bch2_err_str(ret));
                goto err;
        }
 
@@ -1476,7 +1478,7 @@ int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
 
        ret = bch2_journal_flush_device_pins(&c->journal, ca->dev_idx);
        if (ret) {
-               bch_err(ca, "Remove failed: error %i flushing journal", ret);
+               bch_err(ca, "Remove failed: error flushing journal: %s", bch2_err_str(ret));
                goto err;
        }
 
@@ -1488,7 +1490,7 @@ int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
 
        ret = bch2_replicas_gc2(c);
        if (ret) {
-               bch_err(ca, "Remove failed: error %i from replicas gc", ret);
+               bch_err(ca, "Remove failed: error from replicas gc: %s", bch2_err_str(ret));
                goto err;
        }
 
@@ -1542,26 +1544,33 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
 {
        struct bch_opts opts = bch2_opts_empty();
        struct bch_sb_handle sb;
-       const char *err;
        struct bch_dev *ca = NULL;
        struct bch_sb_field_members *mi;
        struct bch_member dev_mi;
        unsigned dev_idx, nr_devices, u64s;
        struct printbuf errbuf = PRINTBUF;
+       struct printbuf label = PRINTBUF;
        int ret;
 
        ret = bch2_read_super(path, &opts, &sb);
        if (ret) {
-               bch_err(c, "device add error: error reading super: %i", ret);
+               bch_err(c, "device add error: error reading super: %s", bch2_err_str(ret));
                goto err;
        }
 
        dev_mi = bch2_sb_get_members(sb.sb)->members[sb.sb->dev_idx];
 
-       err = bch2_dev_may_add(sb.sb, c);
-       if (err) {
-               bch_err(c, "device add error: %s", err);
-               ret = -EINVAL;
+       if (BCH_MEMBER_GROUP(&dev_mi)) {
+               bch2_disk_path_to_text(&label, sb.sb, BCH_MEMBER_GROUP(&dev_mi) - 1);
+               if (label.allocation_failure) {
+                       ret = -ENOMEM;
+                       goto err;
+               }
+       }
+
+       ret = bch2_dev_may_add(sb.sb, c);
+       if (ret) {
+               bch_err(c, "device add error: %s", bch2_err_str(ret));
                goto err;
        }
 
@@ -1601,7 +1610,7 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
                                le32_to_cpu(mi->field.u64s) +
                                sizeof(dev_mi) / sizeof(u64))) {
                bch_err(c, "device add error: new device superblock too small");
-               ret = -ENOSPC;
+               ret = -BCH_ERR_ENOSPC_sb_members;
                goto err_unlock;
        }
 
@@ -1614,7 +1623,7 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
                        goto have_slot;
 no_slot:
        bch_err(c, "device add error: already have maximum number of devices");
-       ret = -ENOSPC;
+       ret = -BCH_ERR_ENOSPC_sb_members;
        goto err_unlock;
 
 have_slot:
@@ -1625,7 +1634,7 @@ have_slot:
        mi = bch2_sb_resize_members(&c->disk_sb, u64s);
        if (!mi) {
                bch_err(c, "device add error: no room in superblock for member info");
-               ret = -ENOSPC;
+               ret = -BCH_ERR_ENOSPC_sb_members;
                goto err_unlock;
        }
 
@@ -1638,6 +1647,14 @@ have_slot:
        ca->disk_sb.sb->dev_idx = dev_idx;
        bch2_dev_attach(c, ca, dev_idx);
 
+       if (BCH_MEMBER_GROUP(&dev_mi)) {
+               ret = __bch2_dev_group_set(c, ca, label.buf);
+               if (ret) {
+                       bch_err(c, "device add error: error setting label");
+                       goto err_unlock;
+               }
+       }
+
        bch2_write_super(c);
        mutex_unlock(&c->sb_lock);
 
@@ -1645,13 +1662,13 @@ have_slot:
 
        ret = bch2_trans_mark_dev_sb(c, ca);
        if (ret) {
-               bch_err(c, "device add error: error marking new superblock: %i", ret);
+               bch_err(c, "device add error: error marking new superblock: %s", bch2_err_str(ret));
                goto err_late;
        }
 
        ret = bch2_fs_freespace_init(c);
        if (ret) {
-               bch_err(c, "device add error: error initializing free space: %i", ret);
+               bch_err(c, "device add error: error initializing free space: %s", bch2_err_str(ret));
                goto err_late;
        }
 
@@ -1670,6 +1687,7 @@ err:
        if (ca)
                bch2_dev_free(ca);
        bch2_free_super(&sb);
+       printbuf_exit(&label);
        printbuf_exit(&errbuf);
        return ret;
 err_late:
@@ -1686,7 +1704,6 @@ int bch2_dev_online(struct bch_fs *c, const char *path)
        struct bch_sb_field_members *mi;
        struct bch_dev *ca;
        unsigned dev_idx;
-       const char *err;
        int ret;
 
        down_write(&c->state_lock);
@@ -1699,9 +1716,9 @@ int bch2_dev_online(struct bch_fs *c, const char *path)
 
        dev_idx = sb.sb->dev_idx;
 
-       err = bch2_dev_in_fs(c->disk_sb.sb, sb.sb);
-       if (err) {
-               bch_err(c, "error bringing %s online: %s", path, err);
+       ret = bch2_dev_in_fs(c->disk_sb.sb, sb.sb);
+       if (ret) {
+               bch_err(c, "error bringing %s online: %s", path, bch2_err_str(ret));
                goto err;
        }
 
@@ -1713,8 +1730,8 @@ int bch2_dev_online(struct bch_fs *c, const char *path)
 
        ret = bch2_trans_mark_dev_sb(c, ca);
        if (ret) {
-               bch_err(c, "error bringing %s online: error %i from bch2_trans_mark_dev_sb",
-                       path, ret);
+               bch_err(c, "error bringing %s online: error from bch2_trans_mark_dev_sb: %s",
+                       path, bch2_err_str(ret));
                goto err;
        }
 
@@ -1730,12 +1747,16 @@ int bch2_dev_online(struct bch_fs *c, const char *path)
        bch2_write_super(c);
        mutex_unlock(&c->sb_lock);
 
+       ret = bch2_fs_freespace_init(c);
+       if (ret)
+               bch_err(c, "device add error: error initializing free space: %s", bch2_err_str(ret));
+
        up_write(&c->state_lock);
        return 0;
 err:
        up_write(&c->state_lock);
        bch2_free_super(&sb);
-       return -EINVAL;
+       return ret;
 }
 
 int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
@@ -1751,7 +1772,7 @@ int bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca, int flags)
        if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
                bch_err(ca, "Cannot offline required disk");
                up_write(&c->state_lock);
-               return -EINVAL;
+               return -BCH_ERR_device_state_not_allowed;
        }
 
        __bch2_dev_offline(c, ca);
@@ -1777,20 +1798,19 @@ int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
            get_capacity(ca->disk_sb.bdev->bd_disk) <
            ca->mi.bucket_size * nbuckets) {
                bch_err(ca, "New size larger than device");
-               ret = -EINVAL;
+               ret = -BCH_ERR_device_size_too_small;
                goto err;
        }
 
        ret = bch2_dev_buckets_resize(c, ca, nbuckets);
        if (ret) {
-               bch_err(ca, "Resize error: %i", ret);
+               bch_err(ca, "Resize error: %s", bch2_err_str(ret));
                goto err;
        }
 
        ret = bch2_trans_mark_dev_sb(c, ca);
-       if (ret) {
+       if (ret)
                goto err;
-       }
 
        mutex_lock(&c->sb_lock);
        mi = &bch2_sb_get_members(c->disk_sb.sb)->members[ca->dev_idx];
@@ -1831,7 +1851,6 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
        struct bch_fs *c = NULL;
        struct bch_sb_field_members *mi;
        unsigned i, best_sb = 0;
-       const char *err;
        struct printbuf errbuf = PRINTBUF;
        int ret = 0;
 
@@ -1869,16 +1888,14 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
        while (i < nr_devices) {
                if (i != best_sb &&
                    !bch2_dev_exists(sb[best_sb].sb, mi, sb[i].sb->dev_idx)) {
-                       char buf[BDEVNAME_SIZE];
-                       pr_info("%s has been removed, skipping",
-                               bdevname(sb[i].bdev, buf));
+                       pr_info("%pg has been removed, skipping", sb[i].bdev);
                        bch2_free_super(&sb[i]);
                        array_remove_item(sb, nr_devices, i);
                        continue;
                }
 
-               err = bch2_dev_in_fs(sb[best_sb].sb, sb[i].sb);
-               if (err)
+               ret = bch2_dev_in_fs(sb[best_sb].sb, sb[i].sb);
+               if (ret)
                        goto err_print;
                i++;
        }
@@ -1899,9 +1916,10 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
        }
        up_write(&c->state_lock);
 
-       err = "insufficient devices";
-       if (!bch2_fs_may_start(c))
+       if (!bch2_fs_may_start(c)) {
+               ret = -BCH_ERR_insufficient_devices_to_start;
                goto err_print;
+       }
 
        if (!c->opts.nostart) {
                ret = bch2_fs_start(c);
@@ -1912,12 +1930,12 @@ out:
        kfree(sb);
        printbuf_exit(&errbuf);
        module_put(THIS_MODULE);
-       pr_verbose_init(opts, "ret %i", PTR_ERR_OR_ZERO(c));
+       pr_verbose_init(opts, "ret %s (%i)", bch2_err_str(PTR_ERR_OR_ZERO(c)),
+                       PTR_ERR_OR_ZERO(c));
        return c;
 err_print:
        pr_err("bch_fs_open err opening %s: %s",
-              devices[0], err);
-       ret = -EINVAL;
+              devices[0], bch2_err_str(ret));
 err:
        if (!IS_ERR_OR_NULL(c))
                bch2_fs_stop(c);
@@ -1964,5 +1982,8 @@ err:
 BCH_DEBUG_PARAMS()
 #undef BCH_DEBUG_PARAM
 
+unsigned bch2_metadata_version = bcachefs_metadata_version_current;
+module_param_named(version, bch2_metadata_version, uint, 0400);
+
 module_exit(bcachefs_exit);
 module_init(bcachefs_init);