From ba89083e9f5d9d26f64565ec3ecb823b5bcad055 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Fri, 8 Mar 2024 19:57:22 -0500 Subject: [PATCH] bcachefs: Fix journal replay with unreadable btree roots When a btree root is unreadable, we still might be able to get some data back by replaying what's in the journal. Previously though, we got confused when journal replay would attempt to replay a key for a level that didn't exist. This adds bch2_btree_increase_depth(), so that journal replay can handle this. Signed-off-by: Kent Overstreet --- fs/bcachefs/btree_iter.c | 4 +- fs/bcachefs/btree_update_interior.c | 59 ++++++++++++++++++++++++++--- fs/bcachefs/btree_update_interior.h | 2 + fs/bcachefs/recovery.c | 11 ++++++ 4 files changed, 70 insertions(+), 6 deletions(-) diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c index 3ef338df82f5..cab2e3fa900b 100644 --- a/fs/bcachefs/btree_iter.c +++ b/fs/bcachefs/btree_iter.c @@ -1729,7 +1729,9 @@ bch2_btree_iter_traverse(struct btree_iter *iter) if (ret) return ret; - btree_path_set_should_be_locked(trans->paths + iter->path); + struct btree_path *path = btree_iter_path(trans, iter); + if (btree_path_node(path, path->level)) + btree_path_set_should_be_locked(path); return 0; } diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c index 4530b14ff2c3..7203ea8d5026 100644 --- a/fs/bcachefs/btree_update_interior.c +++ b/fs/bcachefs/btree_update_interior.c @@ -1208,10 +1208,6 @@ static void bch2_btree_set_root_inmem(struct bch_fs *c, struct btree *b) mutex_unlock(&c->btree_cache.lock); mutex_lock(&c->btree_root_lock); - BUG_ON(btree_node_root(c, b) && - (b->c.level < btree_node_root(c, b)->c.level || - !btree_node_dying(btree_node_root(c, b)))); - bch2_btree_id_root(c, b->c.btree_id)->b = b; mutex_unlock(&c->btree_root_lock); @@ -1747,7 +1743,6 @@ int bch2_btree_split_leaf(struct btree_trans *trans, unsigned flags) { /* btree_split & merge may both cause paths array to be reallocated */ - struct btree *b = path_l(trans->paths + path)->b; struct btree_update *as; unsigned l; @@ -1775,6 +1770,60 @@ int bch2_btree_split_leaf(struct btree_trans *trans, return ret; } +static void __btree_increase_depth(struct btree_update *as, struct btree_trans *trans, + btree_path_idx_t path_idx) +{ + struct bch_fs *c = as->c; + struct btree_path *path = trans->paths + path_idx; + struct btree *n, *b = bch2_btree_id_root(c, path->btree_id)->b; + + BUG_ON(!btree_node_locked(path, b->c.level)); + + n = __btree_root_alloc(as, trans, b->c.level + 1); + + bch2_btree_update_add_new_node(as, n); + six_unlock_write(&n->c.lock); + + path->locks_want++; + BUG_ON(btree_node_locked(path, n->c.level)); + six_lock_increment(&n->c.lock, SIX_LOCK_intent); + mark_btree_node_locked(trans, path, n->c.level, BTREE_NODE_INTENT_LOCKED); + bch2_btree_path_level_init(trans, path, n); + + n->sib_u64s[0] = U16_MAX; + n->sib_u64s[1] = U16_MAX; + + bch2_keylist_add(&as->parent_keys, &b->key); + btree_split_insert_keys(as, trans, path_idx, n, &as->parent_keys); + + bch2_btree_set_root(as, trans, path, n); + bch2_btree_update_get_open_buckets(as, n); + bch2_btree_node_write(c, n, SIX_LOCK_intent, 0); + bch2_trans_node_add(trans, path, n); + six_unlock_intent(&n->c.lock); + + mutex_lock(&c->btree_cache.lock); + list_add_tail(&b->list, &c->btree_cache.live); + mutex_unlock(&c->btree_cache.lock); + + bch2_trans_verify_locks(trans); +} + +int bch2_btree_increase_depth(struct btree_trans *trans, btree_path_idx_t path, unsigned flags) +{ + struct bch_fs *c = trans->c; + struct btree *b = bch2_btree_id_root(c, trans->paths[path].btree_id)->b; + struct btree_update *as = + bch2_btree_update_start(trans, trans->paths + path, + b->c.level, true, flags); + if (IS_ERR(as)) + return PTR_ERR(as); + + __btree_increase_depth(as, trans, path); + bch2_btree_update_done(as, trans); + return 0; +} + int __bch2_foreground_maybe_merge(struct btree_trans *trans, btree_path_idx_t path, unsigned level, diff --git a/fs/bcachefs/btree_update_interior.h b/fs/bcachefs/btree_update_interior.h index c593c925d1e3..3439b03719c7 100644 --- a/fs/bcachefs/btree_update_interior.h +++ b/fs/bcachefs/btree_update_interior.h @@ -119,6 +119,8 @@ struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *, int bch2_btree_split_leaf(struct btree_trans *, btree_path_idx_t, unsigned); +int bch2_btree_increase_depth(struct btree_trans *, btree_path_idx_t, unsigned); + int __bch2_foreground_maybe_merge(struct btree_trans *, btree_path_idx_t, unsigned, unsigned, enum btree_node_sibling); diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c index 1aa21adc7ee5..39271d2d63d1 100644 --- a/fs/bcachefs/recovery.c +++ b/fs/bcachefs/recovery.c @@ -124,6 +124,17 @@ static int bch2_journal_replay_key(struct btree_trans *trans, if (ret) goto out; + struct btree_path *path = btree_iter_path(trans, &iter); + if (unlikely(!btree_path_node(path, k->level))) { + bch2_trans_iter_exit(trans, &iter); + bch2_trans_node_iter_init(trans, &iter, k->btree_id, k->k->k.p, + BTREE_MAX_DEPTH, 0, iter_flags); + ret = bch2_btree_iter_traverse(&iter) ?: + bch2_btree_increase_depth(trans, iter.path, 0) ?: + -BCH_ERR_transaction_restart_nested; + goto out; + } + /* Must be checked with btree locked: */ if (k->overwritten) goto out; -- 2.20.1