From b41ac97fe0a6876edbc6fc90dfd05513ba7332ed Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Tue, 9 Apr 2024 23:53:57 -0400 Subject: [PATCH] bcachefs: Path must be locked if trans->locked && should_be_locked If path->should_be_locked is true, that means user code (of the btree API) has seen, in this transaction, something guarded by the node this path has locked, and we have to keep it locked until the end of the transaction. Assert that we're not violating this; should_be_locked should also be cleared only in _very_ special situations. Signed-off-by: Kent Overstreet --- fs/bcachefs/btree_iter.c | 1 + fs/bcachefs/btree_iter.h | 1 + fs/bcachefs/btree_locking.c | 17 +++++++++-------- 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c index 77b91dd62d95..97f3faac8067 100644 --- a/fs/bcachefs/btree_iter.c +++ b/fs/bcachefs/btree_iter.c @@ -1979,6 +1979,7 @@ struct btree *bch2_btree_iter_next_node(struct btree_trans *trans, struct btree_ /* got to end? */ if (!btree_path_node(path, path->level + 1)) { + path->should_be_locked = false; btree_path_set_level_up(trans, path); return NULL; } diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h index 7cb2c38b70c0..2cabb5f0f484 100644 --- a/fs/bcachefs/btree_iter.h +++ b/fs/bcachefs/btree_iter.h @@ -50,6 +50,7 @@ static inline void btree_path_set_dirty(struct btree_trans *trans, struct btree_path *path, enum btree_path_uptodate u) { + BUG_ON(path->should_be_locked && trans->locked && !trans->restarted); path->uptodate = max_t(unsigned, path->uptodate, u); } diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c index 2cdc9a04f3e8..2f2aed0c9916 100644 --- a/fs/bcachefs/btree_locking.c +++ b/fs/bcachefs/btree_locking.c @@ -882,14 +882,15 @@ int __bch2_trans_mutex_lock(struct btree_trans *trans, void __bch2_btree_path_verify_locks(struct btree_trans *trans, struct btree_path *path) { - /* - * A path may be uptodate and yet have nothing locked if and only if - * there is no node at path->level, which generally means we were - * iterating over all nodes and got to the end of the btree - */ - BUG_ON(path->uptodate == BTREE_ITER_UPTODATE && - btree_path_node(path, path->level) && - !path->nodes_locked); + if (!path->nodes_locked && btree_path_node(path, path->level)) { + /* + * A path may be uptodate and yet have nothing locked if and only if + * there is no node at path->level, which generally means we were + * iterating over all nodes and got to the end of the btree + */ + BUG_ON(path->uptodate == BTREE_ITER_UPTODATE); + BUG_ON(path->should_be_locked && trans->locked && !trans->restarted); + } if (!path->nodes_locked) return; -- 2.25.1