bcachefs: Path must be locked if trans->locked && path->should_be_locked

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

4 files changed, 33 insertions, 23 deletions

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index bfd97d08a15a..56349265970d 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -232,7 +232,7 @@ static void bch2_btree_path_verify(struct btree_trans *trans,
 		bch2_btree_path_verify_level(trans, path, i);
 	}
 
-	bch2_btree_path_verify_locks(path);
+	bch2_btree_path_verify_locks(trans, path);
 }
 
 void bch2_trans_verify_paths(struct btree_trans *trans)
@@ -977,7 +977,7 @@ static __always_inline int btree_path_down(struct btree_trans *trans,
 	path->level = level;
 	bch2_btree_path_level_init(trans, path, b);
 
-	bch2_btree_path_verify_locks(path);
+	bch2_btree_path_verify_locks(trans, path);
 err:
 	bch2_bkey_buf_exit(&tmp, c);
 	return ret;
diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c
index 9cd496fc05a1..8b7c6508f8ed 100644
--- a/fs/bcachefs/btree_locking.c
+++ b/fs/bcachefs/btree_locking.c
@@ -620,7 +620,7 @@ bool bch2_btree_path_upgrade_nounlock(struct btree_trans *trans,
 		}
 	}
 
-	bch2_btree_path_verify_locks(path);
+	bch2_btree_path_verify_locks(trans, path);
 	return path->locks_want == new_locks_want;
 }
 
@@ -648,8 +648,10 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans,
 	path->locks_want = new_locks_want;
 
 	bool ret = btree_path_get_locks(trans, path, true, f);
-	if (ret)
-		goto out;
+	if (ret) {
+		bch2_trans_verify_locks(trans);
+		return true;
+	}
 
 	/*
 	 * XXX: this is ugly - we'd prefer to not be mucking with other
@@ -683,9 +685,8 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans,
 				btree_path_get_locks(trans, linked, true, NULL);
 			}
 	}
-out:
-	bch2_trans_verify_locks(trans);
-	return ret;
+
+	return false;
 }
 
 void __bch2_btree_path_downgrade(struct btree_trans *trans,
@@ -714,7 +715,7 @@ void __bch2_btree_path_downgrade(struct btree_trans *trans,
 		}
 	}
 
-	bch2_btree_path_verify_locks(path);
+	bch2_btree_path_verify_locks(trans, path);
 
 	trace_path_downgrade(trans, _RET_IP_, path, old_locks_want);
 }
@@ -852,16 +853,17 @@ int __bch2_trans_mutex_lock(struct btree_trans *trans,
 
 #ifdef CONFIG_BCACHEFS_DEBUG
 
-void bch2_btree_path_verify_locks(struct btree_path *path)
+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;
@@ -904,7 +906,7 @@ void bch2_trans_verify_locks(struct btree_trans *trans)
 	unsigned i;
 
 	trans_for_each_path(trans, path, i)
-		bch2_btree_path_verify_locks(path);
+		bch2_btree_path_verify_locks(trans, path);
 }
 
 #endif
diff --git a/fs/bcachefs/btree_locking.h b/fs/bcachefs/btree_locking.h
index 568d4794e562..97754cd68a57 100644
--- a/fs/bcachefs/btree_locking.h
+++ b/fs/bcachefs/btree_locking.h
@@ -14,10 +14,10 @@
 #include "six.h"
 
 #ifdef CONFIG_BCACHEFS_DEBUG
-void bch2_btree_path_verify_locks(struct btree_path *);
+void bch2_btree_path_verify_locks(struct btree_trans *, struct btree_path *);
 void bch2_trans_verify_locks(struct btree_trans *);
 #else
-static inline void bch2_btree_path_verify_locks(struct btree_path *path) {}
+static inline void bch2_btree_path_verify_locks(struct btree_trans *, struct btree_path *path) {}
 static inline void bch2_trans_verify_locks(struct btree_trans *trans) {}
 #endif
 
@@ -165,6 +165,13 @@ static inline void __bch2_btree_path_unlock(struct btree_trans *trans,
 		btree_node_unlock(trans, path, btree_path_lowest_level_locked(path));
 }
 
+static inline void bch2_btree_path_unlock_dontneed(struct btree_trans *trans,
+						   struct btree_path *path)
+{
+	path->should_be_locked = false;
+	__bch2_btree_path_unlock(trans, path);
+}
+
 /*
  * Updates the saved lock sequence number, so that bch2_btree_node_relock() will
  * succeed:
diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c
index 50790a919c52..17772094e43c 100644
--- a/fs/bcachefs/btree_update_interior.c
+++ b/fs/bcachefs/btree_update_interior.c
@@ -1611,6 +1611,7 @@ static int btree_split(struct btree_update *as, struct btree_trans *trans,
 	u64 start_time = local_clock();
 	int ret = 0;
 
+	bch2_trans_verify_locks(trans);
 	bch2_verify_btree_nr_keys(b);
 	BUG_ON(!parent && (b != btree_node_root(c, b)));
 	BUG_ON(parent && !btree_node_intent_locked(trans->paths + path, b->c.level + 1));
@@ -1749,11 +1750,11 @@ static int btree_split(struct btree_update *as, struct btree_trans *trans,
 	bch2_trans_node_add(trans, trans->paths + path1, n1);
 out:
 	if (path2) {
-		__bch2_btree_path_unlock(trans, trans->paths + path2);
+		bch2_btree_path_unlock_dontneed(trans, trans->paths + path2);
 		bch2_path_put(trans, path2, true);
 	}
 	if (path1) {
-		__bch2_btree_path_unlock(trans, trans->paths + path1);
+		bch2_btree_path_unlock_dontneed(trans, trans->paths + path1);
 		bch2_path_put(trans, path1, true);
 	}