]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/recovery.c
Update bcachefs sources to 386f00b639 bcachefs: Snapshot creation, deletion
[bcachefs-tools-debian] / libbcachefs / recovery.c
index f8efeb36420618ed8c5ac8f101416fbca09db9c3..64e0b542e7791d53cf0a0b5323e00e3e79656800 100644 (file)
 #include "journal_io.h"
 #include "journal_reclaim.h"
 #include "journal_seq_blacklist.h"
+#include "move.h"
 #include "quota.h"
 #include "recovery.h"
 #include "replicas.h"
+#include "subvolume.h"
 #include "super-io.h"
 
 #include <linux/sort.h>
@@ -38,6 +40,20 @@ static void drop_alloc_keys(struct journal_keys *keys)
        keys->nr = dst;
 }
 
+/*
+ * Btree node pointers have a field to stack a pointer to the in memory btree
+ * node; we need to zero out this field when reading in btree nodes, or when
+ * reading in keys from the journal:
+ */
+static void zero_out_btree_mem_ptr(struct journal_keys *keys)
+{
+       struct journal_key *i;
+
+       for (i = keys->d; i < keys->d + keys->nr; i++)
+               if (i->k->k.type == KEY_TYPE_btree_ptr_v2)
+                       bkey_i_to_btree_ptr_v2(i->k)->v.mem_ptr = 0;
+}
+
 /* iterate over keys read from the journal: */
 
 static int __journal_key_cmp(enum btree_id     l_btree_id,
@@ -47,14 +63,14 @@ static int __journal_key_cmp(enum btree_id  l_btree_id,
 {
        return (cmp_int(l_btree_id,     r->btree_id) ?:
                cmp_int(l_level,        r->level) ?:
-               bkey_cmp(l_pos, r->k->k.p));
+               bpos_cmp(l_pos, r->k->k.p));
 }
 
 static int journal_key_cmp(struct journal_key *l, struct journal_key *r)
 {
        return (cmp_int(l->btree_id,    r->btree_id) ?:
                cmp_int(l->level,       r->level) ?:
-               bkey_cmp(l->k->k.p,     r->k->k.p));
+               bpos_cmp(l->k->k.p,     r->k->k.p));
 }
 
 static size_t journal_key_search(struct journal_keys *journal_keys,
@@ -89,7 +105,7 @@ static void journal_iter_fix(struct bch_fs *c, struct journal_iter *iter, unsign
        if (iter->idx > idx ||
            (iter->idx == idx &&
             biter->last &&
-            bkey_cmp(n->k.p, biter->unpacked.p) <= 0))
+            bpos_cmp(n->k.p, biter->unpacked.p) <= 0))
                iter->idx++;
 }
 
@@ -237,7 +253,7 @@ struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *
                        bkey_i_to_s_c(bch2_journal_iter_peek(&iter->journal));
 
                if (btree_k.k && journal_k.k) {
-                       int cmp = bkey_cmp(btree_k.k->p, journal_k.k->p);
+                       int cmp = bpos_cmp(btree_k.k->p, journal_k.k->p);
 
                        if (!cmp)
                                bch2_journal_iter_advance_btree(iter);
@@ -255,7 +271,7 @@ struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *
                ret = iter->last == journal ? journal_k : btree_k;
 
                if (iter->b &&
-                   bkey_cmp(ret.k->p, iter->b->data->max_key) > 0) {
+                   bpos_cmp(ret.k->p, iter->b->data->max_key) > 0) {
                        iter->journal.idx = iter->journal.keys->nr;
                        iter->last = none;
                        return bkey_s_c_null;
@@ -311,7 +327,7 @@ static void btree_and_journal_iter_prefetch(struct bch_fs *c, struct btree *b,
               (k = bch2_btree_and_journal_iter_peek(&iter)).k) {
                bch2_bkey_buf_reassemble(&tmp, c, k);
 
-               bch2_btree_node_prefetch(c, NULL, tmp.k,
+               bch2_btree_node_prefetch(c, NULL, NULL, tmp.k,
                                        b->c.btree_id, b->c.level - 1);
 
                bch2_btree_and_journal_iter_advance(&iter);
@@ -322,9 +338,7 @@ static void btree_and_journal_iter_prefetch(struct bch_fs *c, struct btree *b,
 }
 
 static int bch2_btree_and_journal_walk_recurse(struct bch_fs *c, struct btree *b,
-                               struct journal_keys *journal_keys,
                                enum btree_id btree_id,
-                               btree_walk_node_fn node_fn,
                                btree_walk_key_fn key_fn)
 {
        struct btree_and_journal_iter iter;
@@ -337,15 +351,9 @@ static int bch2_btree_and_journal_walk_recurse(struct bch_fs *c, struct btree *b
        bch2_btree_and_journal_iter_init_node_iter(&iter, c, b);
 
        while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
-               ret = key_fn(c, btree_id, b->c.level, k);
-               if (ret)
-                       break;
-
                if (b->c.level) {
                        bch2_bkey_buf_reassemble(&tmp, c, k);
 
-                       bch2_btree_and_journal_iter_advance(&iter);
-
                        child = bch2_btree_node_get_noiter(c, tmp.k,
                                                b->c.btree_id, b->c.level - 1,
                                                false);
@@ -356,16 +364,17 @@ static int bch2_btree_and_journal_walk_recurse(struct bch_fs *c, struct btree *b
 
                        btree_and_journal_iter_prefetch(c, b, iter);
 
-                       ret   = (node_fn ? node_fn(c, b) : 0) ?:
-                               bch2_btree_and_journal_walk_recurse(c, child,
-                                       journal_keys, btree_id, node_fn, key_fn);
+                       ret = bch2_btree_and_journal_walk_recurse(c, child,
+                                       btree_id, key_fn);
                        six_unlock_read(&child->c.lock);
-
-                       if (ret)
-                               break;
                } else {
-                       bch2_btree_and_journal_iter_advance(&iter);
+                       ret = key_fn(c, k);
                }
+
+               if (ret)
+                       break;
+
+               bch2_btree_and_journal_iter_advance(&iter);
        }
 
        bch2_btree_and_journal_iter_exit(&iter);
@@ -373,9 +382,7 @@ static int bch2_btree_and_journal_walk_recurse(struct bch_fs *c, struct btree *b
        return ret;
 }
 
-int bch2_btree_and_journal_walk(struct bch_fs *c, struct journal_keys *journal_keys,
-                               enum btree_id btree_id,
-                               btree_walk_node_fn node_fn,
+int bch2_btree_and_journal_walk(struct bch_fs *c, enum btree_id btree_id,
                                btree_walk_key_fn key_fn)
 {
        struct btree *b = c->btree_roots[btree_id].b;
@@ -385,10 +392,7 @@ int bch2_btree_and_journal_walk(struct bch_fs *c, struct journal_keys *journal_k
                return 0;
 
        six_lock_read(&b->c.lock, NULL, NULL);
-       ret   = (node_fn ? node_fn(c, b) : 0) ?:
-               bch2_btree_and_journal_walk_recurse(c, b, journal_keys, btree_id,
-                                                   node_fn, key_fn) ?:
-               key_fn(c, btree_id, b->c.level + 1, bkey_i_to_s_c(&b->key));
+       ret = bch2_btree_and_journal_walk_recurse(c, b, btree_id, key_fn);
        six_unlock_read(&b->c.lock);
 
        return ret;
@@ -418,7 +422,7 @@ static int journal_sort_key_cmp(const void *_l, const void *_r)
 
        return  cmp_int(l->btree_id,    r->btree_id) ?:
                cmp_int(l->level,       r->level) ?:
-               bkey_cmp(l->k->k.p, r->k->k.p) ?:
+               bpos_cmp(l->k->k.p, r->k->k.p) ?:
                cmp_int(l->journal_seq, r->journal_seq) ?:
                cmp_int(l->journal_offset, r->journal_offset);
 }
@@ -489,7 +493,7 @@ static struct journal_keys journal_keys_sort(struct list_head *journal_entries)
                while (src + 1 < keys.d + keys.nr &&
                       src[0].btree_id  == src[1].btree_id &&
                       src[0].level     == src[1].level &&
-                      !bkey_cmp(src[0].k->k.p, src[1].k->k.p))
+                      !bpos_cmp(src[0].k->k.p, src[1].k->k.p))
                        src++;
 
                *dst++ = *src++;
@@ -515,24 +519,16 @@ static int __bch2_journal_replay_key(struct btree_trans *trans,
                                     enum btree_id id, unsigned level,
                                     struct bkey_i *k)
 {
-       struct btree_iter *iter;
+       struct btree_iter iter;
        int ret;
 
-       iter = bch2_trans_get_node_iter(trans, id, k->k.p,
-                                       BTREE_MAX_DEPTH, level,
-                                       BTREE_ITER_INTENT);
-
-       /*
-        * iter->flags & BTREE_ITER_IS_EXTENTS triggers the update path to run
-        * extent_handle_overwrites() and extent_update_to_keys() - but we don't
-        * want that here, journal replay is supposed to treat extents like
-        * regular keys:
-        */
-       BUG_ON(iter->flags & BTREE_ITER_IS_EXTENTS);
-
-       ret   = bch2_btree_iter_traverse(iter) ?:
-               bch2_trans_update(trans, iter, k, BTREE_TRIGGER_NORUN);
-       bch2_trans_iter_put(trans, iter);
+       bch2_trans_node_iter_init(trans, &iter, id, k->k.p,
+                                 BTREE_MAX_DEPTH, level,
+                                 BTREE_ITER_INTENT|
+                                 BTREE_ITER_NOT_EXTENTS);
+       ret   = bch2_btree_iter_traverse(&iter) ?:
+               bch2_trans_update(trans, &iter, k, BTREE_TRIGGER_NORUN);
+       bch2_trans_iter_exit(trans, &iter);
        return ret;
 }
 
@@ -550,15 +546,16 @@ static int bch2_journal_replay_key(struct bch_fs *c, struct journal_key *k)
 
 static int __bch2_alloc_replay_key(struct btree_trans *trans, struct bkey_i *k)
 {
-       struct btree_iter *iter;
+       struct btree_iter iter;
        int ret;
 
-       iter = bch2_trans_get_iter(trans, BTREE_ID_alloc, k->k.p,
-                                  BTREE_ITER_CACHED|
-                                  BTREE_ITER_CACHED_NOFILL|
-                                  BTREE_ITER_INTENT);
-       ret = bch2_trans_update(trans, iter, k, BTREE_TRIGGER_NORUN);
-       bch2_trans_iter_put(trans, iter);
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, k->k.p,
+                            BTREE_ITER_CACHED|
+                            BTREE_ITER_CACHED_NOFILL|
+                            BTREE_ITER_INTENT);
+       ret   = bch2_btree_iter_traverse(&iter) ?:
+               bch2_trans_update(trans, &iter, k, BTREE_TRIGGER_NORUN);
+       bch2_trans_iter_exit(trans, &iter);
        return ret;
 }
 
@@ -580,7 +577,7 @@ static int journal_sort_seq_cmp(const void *_l, const void *_r)
        return  cmp_int(r->level,       l->level) ?:
                cmp_int(l->journal_seq, r->journal_seq) ?:
                cmp_int(l->btree_id,    r->btree_id) ?:
-               bkey_cmp(l->k->k.p,     r->k->k.p);
+               bpos_cmp(l->k->k.p,     r->k->k.p);
 }
 
 static int bch2_journal_replay(struct bch_fs *c,
@@ -727,7 +724,7 @@ static int journal_replay_entry_early(struct bch_fs *c,
        case BCH_JSET_ENTRY_dev_usage: {
                struct jset_entry_dev_usage *u =
                        container_of(entry, struct jset_entry_dev_usage, entry);
-               struct bch_dev *ca = bch_dev_bkey_exists(c, u->dev);
+               struct bch_dev *ca = bch_dev_bkey_exists(c, le32_to_cpu(u->dev));
                unsigned bytes = jset_u64s(le16_to_cpu(entry->u64s)) * sizeof(u64);
                unsigned nr_types = (bytes - sizeof(struct jset_entry_dev_usage)) /
                        sizeof(struct jset_entry_dev_usage_type);
@@ -736,7 +733,7 @@ static int journal_replay_entry_early(struct bch_fs *c,
                ca->usage_base->buckets_ec              = le64_to_cpu(u->buckets_ec);
                ca->usage_base->buckets_unavailable     = le64_to_cpu(u->buckets_unavailable);
 
-               for (i = 0; i < nr_types; i++) {
+               for (i = 0; i < min_t(unsigned, nr_types, BCH_DATA_NR); i++) {
                        ca->usage_base->d[i].buckets    = le64_to_cpu(u->d[i].buckets);
                        ca->usage_base->d[i].sectors    = le64_to_cpu(u->d[i].sectors);
                        ca->usage_base->d[i].fragmented = le64_to_cpu(u->d[i].fragmented);
@@ -766,7 +763,7 @@ static int journal_replay_entry_early(struct bch_fs *c,
                struct jset_entry_clock *clock =
                        container_of(entry, struct jset_entry_clock, entry);
 
-               atomic64_set(&c->io_clock[clock->rw].now, clock->time);
+               atomic64_set(&c->io_clock[clock->rw].now, le64_to_cpu(clock->time));
        }
        }
 
@@ -934,7 +931,7 @@ static int read_btree_roots(struct bch_fs *c)
 
                if (i == BTREE_ID_alloc &&
                    c->opts.reconstruct_alloc) {
-                       c->sb.compat &= ~(1ULL << BCH_COMPAT_FEAT_ALLOC_INFO);
+                       c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                        continue;
                }
 
@@ -944,7 +941,7 @@ static int read_btree_roots(struct bch_fs *c)
                                   "invalid btree root %s",
                                   bch2_btree_ids[i]);
                        if (i == BTREE_ID_alloc)
-                               c->sb.compat &= ~(1ULL << BCH_COMPAT_FEAT_ALLOC_INFO);
+                               c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                }
 
                ret = bch2_btree_root_read(c, i, &r->key, r->level);
@@ -954,7 +951,7 @@ static int read_btree_roots(struct bch_fs *c)
                                   "error reading btree root %s",
                                   bch2_btree_ids[i]);
                        if (i == BTREE_ID_alloc)
-                               c->sb.compat &= ~(1ULL << BCH_COMPAT_FEAT_ALLOC_INFO);
+                               c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                }
        }
 
@@ -965,6 +962,81 @@ fsck_err:
        return ret;
 }
 
+static int bch2_fs_initialize_subvolumes(struct bch_fs *c)
+{
+       struct bkey_i_snapshot  root_snapshot;
+       struct bkey_i_subvolume root_volume;
+       int ret;
+
+       bkey_snapshot_init(&root_snapshot.k_i);
+       root_snapshot.k.p.offset = U32_MAX;
+       root_snapshot.v.flags   = 0;
+       root_snapshot.v.parent  = 0;
+       root_snapshot.v.subvol  = BCACHEFS_ROOT_SUBVOL;
+       root_snapshot.v.pad     = 0;
+       SET_BCH_SNAPSHOT_SUBVOL(&root_snapshot.v, true);
+
+       ret = bch2_btree_insert(c, BTREE_ID_snapshots,
+                               &root_snapshot.k_i,
+                               NULL, NULL, 0);
+       if (ret)
+               return ret;
+
+
+       bkey_subvolume_init(&root_volume.k_i);
+       root_volume.k.p.offset = BCACHEFS_ROOT_SUBVOL;
+       root_volume.v.flags     = 0;
+       root_volume.v.snapshot  = cpu_to_le32(U32_MAX);
+       root_volume.v.inode     = cpu_to_le64(BCACHEFS_ROOT_INO);
+
+       ret = bch2_btree_insert(c, BTREE_ID_subvolumes,
+                               &root_volume.k_i,
+                               NULL, NULL, 0);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static int bch2_fs_upgrade_for_subvolumes(struct btree_trans *trans)
+{
+       struct bch_fs *c = trans->c;
+       struct btree_iter iter;
+       struct bkey_s_c k;
+       struct bch_inode_unpacked inode;
+       struct bkey_inode_buf *packed;
+       int ret;
+
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_inodes,
+                            POS(0, BCACHEFS_ROOT_INO), 0);
+       k = bch2_btree_iter_peek_slot(&iter);
+       ret = bkey_err(k);
+       if (ret)
+               goto err;
+
+       if (k.k->type != KEY_TYPE_inode) {
+               bch_err(c, "root inode not found");
+               ret = -ENOENT;
+               goto err;
+       }
+
+       ret = bch2_inode_unpack(bkey_s_c_to_inode(k), &inode);
+       BUG_ON(ret);
+
+       inode.bi_subvol = BCACHEFS_ROOT_SUBVOL;
+
+       packed = bch2_trans_kmalloc(trans, sizeof(*packed));
+       ret = PTR_ERR_OR_ZERO(packed);
+       if (ret)
+               goto err;
+
+       bch2_inode_pack(c, packed, &inode);
+       ret = bch2_trans_update(trans, &iter, &packed->inode.k_i, 0);
+err:
+       bch2_trans_iter_exit(trans, &iter);
+       return ret;
+}
+
 int bch2_fs_recovery(struct bch_fs *c)
 {
        const char *err = "cannot allocate memory";
@@ -972,7 +1044,7 @@ int bch2_fs_recovery(struct bch_fs *c)
        struct jset *last_journal_entry = NULL;
        u64 blacklist_seq, journal_seq;
        bool write_sb = false;
-       int ret;
+       int ret = 0;
 
        if (c->sb.clean)
                clean = read_superblock_clean(c);
@@ -997,6 +1069,13 @@ int bch2_fs_recovery(struct bch_fs *c)
                goto err;
        }
 
+       if (!(c->sb.compat & (1ULL << BCH_COMPAT_bformat_overflow_done))) {
+               bch_err(c, "filesystem may have incompatible bkey formats; run fsck from the compat branch to fix");
+               ret = -EINVAL;
+               goto err;
+
+       }
+
        if (!(c->sb.features & (1ULL << BCH_FEATURE_alloc_v2))) {
                bch_info(c, "alloc_v2 feature bit not set, fsck required");
                c->opts.fsck = true;
@@ -1009,6 +1088,19 @@ int bch2_fs_recovery(struct bch_fs *c)
                set_bit(BCH_FS_REBUILD_REPLICAS, &c->flags);
        }
 
+       if (c->sb.version < bcachefs_metadata_version_inode_backpointers) {
+               bch_info(c, "version prior to inode backpointers, upgrade and fsck required");
+               c->opts.version_upgrade = true;
+               c->opts.fsck            = true;
+               c->opts.fix_errors      = FSCK_OPT_YES;
+       } else if (c->sb.version < bcachefs_metadata_version_btree_ptr_sectors_written) {
+               bch_info(c, "version prior to btree_ptr_sectors_written, upgrade required");
+               c->opts.version_upgrade = true;
+       } else if (c->sb.version < bcachefs_metadata_version_snapshot) {
+               bch_info(c, "filesystem version is prior to snapshot field - upgrading");
+               c->opts.version_upgrade = true;
+       }
+
        ret = bch2_blacklist_table_initialize(c);
        if (ret) {
                bch_err(c, "error initializing blacklist table");
@@ -1033,7 +1125,7 @@ int bch2_fs_recovery(struct bch_fs *c)
                                        last_journal_entry &&
                                        !journal_entry_empty(last_journal_entry), c,
                                "filesystem marked clean but journal not empty")) {
-                       c->sb.compat &= ~(1ULL << BCH_COMPAT_FEAT_ALLOC_INFO);
+                       c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                        SET_BCH_SB_CLEAN(c->disk_sb.sb, false);
                        c->sb.clean = false;
                }
@@ -1067,10 +1159,12 @@ use_clean:
        }
 
        if (c->opts.reconstruct_alloc) {
-               c->sb.compat &= ~(1ULL << BCH_COMPAT_FEAT_ALLOC_INFO);
+               c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                drop_alloc_keys(&c->journal_keys);
        }
 
+       zero_out_btree_mem_ptr(&c->journal_keys);
+
        ret = journal_replay_early(c, clean, &c->journal_entries);
        if (ret)
                goto err;
@@ -1105,14 +1199,14 @@ use_clean:
 
        bch_verbose(c, "starting alloc read");
        err = "error reading allocation information";
-       ret = bch2_alloc_read(c, &c->journal_keys);
+       ret = bch2_alloc_read(c);
        if (ret)
                goto err;
        bch_verbose(c, "alloc read done");
 
        bch_verbose(c, "starting stripes_read");
        err = "error reading stripes";
-       ret = bch2_stripes_read(c, &c->journal_keys);
+       ret = bch2_stripes_read(c);
        if (ret)
                goto err;
        bch_verbose(c, "stripes_read done");
@@ -1120,12 +1214,14 @@ use_clean:
        set_bit(BCH_FS_ALLOC_READ_DONE, &c->flags);
 
        if (c->opts.fsck ||
-           !(c->sb.compat & (1ULL << BCH_COMPAT_FEAT_ALLOC_INFO)) ||
-           !(c->sb.compat & (1ULL << BCH_COMPAT_FEAT_ALLOC_METADATA)) ||
+           !(c->sb.compat & (1ULL << BCH_COMPAT_alloc_info)) ||
+           !(c->sb.compat & (1ULL << BCH_COMPAT_alloc_metadata)) ||
            test_bit(BCH_FS_REBUILD_REPLICAS, &c->flags)) {
+               bool metadata_only = c->opts.norecovery;
+
                bch_info(c, "starting mark and sweep");
                err = "error in mark and sweep";
-               ret = bch2_gc(c, true);
+               ret = bch2_gc(c, true, metadata_only);
                if (ret)
                        goto err;
                bch_verbose(c, "mark and sweep done");
@@ -1171,23 +1267,27 @@ use_clean:
                bch_verbose(c, "alloc write done");
        }
 
-       if (!c->sb.clean) {
-               if (!(c->sb.features & (1 << BCH_FEATURE_atomic_nlink))) {
-                       bch_info(c, "checking inode link counts");
-                       err = "error in recovery";
-                       ret = bch2_fsck_inode_nlink(c);
-                       if (ret)
-                               goto err;
-                       bch_verbose(c, "check inodes done");
+       if (c->sb.version < bcachefs_metadata_version_snapshot) {
+               err = "error creating root snapshot node";
+               ret = bch2_fs_initialize_subvolumes(c);
+               if (ret)
+                       goto err;
+       }
 
-               } else {
-                       bch_verbose(c, "checking for deleted inodes");
-                       err = "error in recovery";
-                       ret = bch2_fsck_walk_inodes_only(c);
-                       if (ret)
-                               goto err;
-                       bch_verbose(c, "check inodes done");
-               }
+       bch_verbose(c, "reading snapshots table");
+       err = "error reading snapshots table";
+       ret = bch2_fs_snapshots_start(c);
+       if (ret)
+               goto err;
+       bch_verbose(c, "reading snapshots done");
+
+       if (c->sb.version < bcachefs_metadata_version_snapshot) {
+               /* set bi_subvol on root inode */
+               err = "error upgrade root inode for subvolumes";
+               ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_LAZY_RW,
+                                   bch2_fs_upgrade_for_subvolumes(&trans));
+               if (ret)
+                       goto err;
        }
 
        if (c->opts.fsck) {
@@ -1197,6 +1297,13 @@ use_clean:
                if (ret)
                        goto err;
                bch_verbose(c, "fsck done");
+       } else if (!c->sb.clean) {
+               bch_verbose(c, "checking for deleted inodes");
+               err = "error in recovery";
+               ret = bch2_fsck_walk_inodes_only(c);
+               if (ret)
+                       goto err;
+               bch_verbose(c, "check inodes done");
        }
 
        if (enabled_qtypes(c)) {
@@ -1207,16 +1314,40 @@ use_clean:
                bch_verbose(c, "quotas done");
        }
 
+       if (!(c->sb.compat & (1ULL << BCH_COMPAT_extents_above_btree_updates_done)) ||
+           !(c->sb.compat & (1ULL << BCH_COMPAT_bformat_overflow_done))) {
+               struct bch_move_stats stats;
+
+               bch_move_stats_init(&stats, "recovery");
+
+               bch_info(c, "scanning for old btree nodes");
+               ret = bch2_fs_read_write(c);
+               if (ret)
+                       goto err;
+
+               ret = bch2_scan_old_btree_nodes(c, &stats);
+               if (ret)
+                       goto err;
+               bch_info(c, "scanning for old btree nodes done");
+       }
+
        mutex_lock(&c->sb_lock);
+       if (c->opts.version_upgrade) {
+               c->disk_sb.sb->version = cpu_to_le16(bcachefs_metadata_version_current);
+               c->disk_sb.sb->features[0] |= cpu_to_le64(BCH_SB_FEATURES_ALL);
+               write_sb = true;
+       }
+
        if (!test_bit(BCH_FS_ERROR, &c->flags)) {
-               c->disk_sb.sb->compat[0] |= 1ULL << BCH_COMPAT_FEAT_ALLOC_INFO;
+               c->disk_sb.sb->compat[0] |= cpu_to_le64(1ULL << BCH_COMPAT_alloc_info);
                write_sb = true;
        }
 
        if (c->opts.fsck &&
-           !test_bit(BCH_FS_ERROR, &c->flags)) {
-               c->disk_sb.sb->features[0] |= 1ULL << BCH_FEATURE_atomic_nlink;
+           !test_bit(BCH_FS_ERROR, &c->flags) &&
+           !test_bit(BCH_FS_ERRORS_NOT_FIXED, &c->flags)) {
                SET_BCH_SB_HAS_ERRORS(c->disk_sb.sb, 0);
+               SET_BCH_SB_HAS_TOPOLOGY_ERRORS(c->disk_sb.sb, 0);
                write_sb = true;
        }
 
@@ -1227,10 +1358,9 @@ use_clean:
        if (c->journal_seq_blacklist_table &&
            c->journal_seq_blacklist_table->nr > 128)
                queue_work(system_long_wq, &c->journal_seq_blacklist_gc_work);
-out:
+
        ret = 0;
-err:
-fsck_err:
+out:
        set_bit(BCH_FS_FSCK_DONE, &c->flags);
        bch2_flush_fsck_errs(c);
 
@@ -1244,6 +1374,10 @@ fsck_err:
        else
                bch_verbose(c, "ret %i", ret);
        return ret;
+err:
+fsck_err:
+       bch2_fs_emergency_read_only(c);
+       goto out;
 }
 
 int bch2_fs_initialize(struct bch_fs *c)
@@ -1260,6 +1394,15 @@ int bch2_fs_initialize(struct bch_fs *c)
        bch_notice(c, "initializing new filesystem");
 
        mutex_lock(&c->sb_lock);
+       c->disk_sb.sb->compat[0] |= cpu_to_le64(1ULL << BCH_COMPAT_extents_above_btree_updates_done);
+       c->disk_sb.sb->compat[0] |= cpu_to_le64(1ULL << BCH_COMPAT_bformat_overflow_done);
+
+       if (c->opts.version_upgrade) {
+               c->disk_sb.sb->version = cpu_to_le16(bcachefs_metadata_version_current);
+               c->disk_sb.sb->features[0] |= cpu_to_le64(BCH_SB_FEATURES_ALL);
+               bch2_write_super(c);
+       }
+
        for_each_online_member(ca, c, i)
                bch2_mark_dev_superblock(c, ca, 0);
        mutex_unlock(&c->sb_lock);
@@ -1298,15 +1441,33 @@ int bch2_fs_initialize(struct bch_fs *c)
         * Write out the superblock and journal buckets, now that we can do
         * btree updates
         */
-       err = "error writing alloc info";
-       ret = bch2_alloc_write(c, 0);
+       err = "error marking superblock and journal";
+       for_each_member_device(ca, c, i) {
+               ret = bch2_trans_mark_dev_sb(c, ca);
+               if (ret) {
+                       percpu_ref_put(&ca->ref);
+                       goto err;
+               }
+       }
+
+       err = "error creating root snapshot node";
+       ret = bch2_fs_initialize_subvolumes(c);
+       if (ret)
+               goto err;
+
+       bch_verbose(c, "reading snapshots table");
+       err = "error reading snapshots table";
+       ret = bch2_fs_snapshots_start(c);
        if (ret)
                goto err;
+       bch_verbose(c, "reading snapshots done");
 
        bch2_inode_init(c, &root_inode, 0, 0,
                        S_IFDIR|S_IRWXU|S_IRUGO|S_IXUGO, 0, NULL);
-       root_inode.bi_inum = BCACHEFS_ROOT_INO;
+       root_inode.bi_inum      = BCACHEFS_ROOT_INO;
+       root_inode.bi_subvol    = BCACHEFS_ROOT_SUBVOL;
        bch2_inode_pack(c, &packed_inode, &root_inode);
+       packed_inode.inode.k.p.snapshot = U32_MAX;
 
        err = "error creating root directory";
        ret = bch2_btree_insert(c, BTREE_ID_inodes,
@@ -1319,11 +1480,12 @@ int bch2_fs_initialize(struct bch_fs *c)
 
        err = "error creating lost+found";
        ret = bch2_trans_do(c, NULL, NULL, 0,
-               bch2_create_trans(&trans, BCACHEFS_ROOT_INO,
+               bch2_create_trans(&trans,
+                                 BCACHEFS_ROOT_SUBVOL_INUM,
                                  &root_inode, &lostfound_inode,
                                  &lostfound,
                                  0, 0, S_IFDIR|0700, 0,
-                                 NULL, NULL));
+                                 NULL, NULL, (subvol_inum) { 0 }, 0));
        if (ret) {
                bch_err(c, "error creating lost+found");
                goto err;