From 5c792e1b64cb5b87129f7226d610fd63465039bd Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Fri, 2 Dec 2022 12:45:37 -0500 Subject: [PATCH] bcachefs: Fix a btree iter assertion pop This fixes a (harmless) broken invariant in __bch2_btree_path_set_pos(): iterators to interior nodes should point to the first non whiteout. Signed-off-by: Kent Overstreet --- fs/bcachefs/btree_iter.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c index ecb6f27e49177..ff796a74fd2fa 100644 --- a/fs/bcachefs/btree_iter.c +++ b/fs/bcachefs/btree_iter.c @@ -1202,7 +1202,7 @@ __bch2_btree_path_set_pos(struct btree_trans *trans, struct btree_path *path, struct bpos new_pos, bool intent, int cmp) { - unsigned l = path->level; + unsigned level = path->level; EBUG_ON(trans->restarted); EBUG_ON(!path->ref); @@ -1219,10 +1219,12 @@ __bch2_btree_path_set_pos(struct btree_trans *trans, goto out; } - l = btree_path_up_until_good_node(trans, path, cmp); + level = btree_path_up_until_good_node(trans, path, cmp); - if (btree_path_node(path, l)) { - BUG_ON(!btree_node_locked(path, l)); + if (btree_path_node(path, level)) { + struct btree_path_level *l = &path->l[level]; + + BUG_ON(!btree_node_locked(path, level)); /* * We might have to skip over many keys, or just a few: try * advancing the node iterator, and if we have to skip over too @@ -1230,11 +1232,18 @@ __bch2_btree_path_set_pos(struct btree_trans *trans, * is expensive). */ if (cmp < 0 || - !btree_path_advance_to_pos(path, &path->l[l], 8)) - __btree_path_level_init(path, l); + !btree_path_advance_to_pos(path, l, 8)) + bch2_btree_node_iter_init(&l->iter, l->b, &path->pos); + + /* + * Iterators to interior nodes should always be pointed at the first non + * whiteout: + */ + if (unlikely(level)) + bch2_btree_node_iter_peek(&l->iter, l->b); } - if (l != path->level) { + if (unlikely(level != path->level)) { btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); __bch2_btree_path_unlock(trans, path); } -- 2.30.2