bcachefs: bch2_trans_in_restart_error()

This replaces various BUG_ON() assertions with panics that tell us where
the restart was done and the restart type.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_iter.c

@@ -1224,7 +1224,7 @@ __bch2_btree_path_set_pos(struct btree_trans *trans,
 {
 	unsigned level = path->level;
 
-	EBUG_ON(trans->restarted);
+	bch2_trans_verify_not_in_restart(trans);
 	EBUG_ON(!path->ref);
 
 	path = bch2_btree_path_make_mut(trans, path, intent, ip);
@@ -1353,6 +1353,20 @@ static void bch2_path_put_nokeep(struct btree_trans *trans, struct btree_path *p
 	__bch2_path_free(trans, path);
 }
 
+void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count)
+{
+	panic("trans->restart_count %u, should be %u, last restarted by %pS\n",
+	      trans->restart_count, restart_count,
+	      (void *) trans->last_restarted_ip);
+}
+
+void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans)
+{
+	panic("in transaction restart: %s, last restarted by %pS\n",
+	      bch2_err_str(trans->restarted),
+	      (void *) trans->last_restarted_ip);
+}
+
 noinline __cold
 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans)
 {
@@ -1519,7 +1533,7 @@ struct btree_path *bch2_path_get(struct btree_trans *trans,
 	bool intent = flags & BTREE_ITER_INTENT;
 	int i;
 
-	EBUG_ON(trans->restarted);
+	bch2_trans_verify_not_in_restart(trans);
 	bch2_trans_verify_locks(trans);
 
 	btree_trans_sort_paths(trans);
@@ -1695,7 +1709,7 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 	struct btree *b = NULL;
 	int ret;
 
-	BUG_ON(trans->restarted);
+	bch2_trans_verify_not_in_restart(trans);
 	EBUG_ON(iter->path->cached);
 	bch2_btree_iter_verify(iter);
 
@@ -2833,14 +2847,6 @@ u32 bch2_trans_begin(struct btree_trans *trans)
 	return trans->restart_count;
 }
 
-void bch2_trans_verify_not_restarted(struct btree_trans *trans, u32 restart_count)
-{
-	if (trans_was_restarted(trans, restart_count))
-		panic("trans->restart_count %u, should be %u, last restarted by %pS\n",
-		      trans->restart_count, restart_count,
-		      (void *) trans->last_restarted_ip);
-}
-
 static void bch2_trans_alloc_paths(struct btree_trans *trans, struct bch_fs *c)
 {
 	size_t paths_bytes	= sizeof(struct btree_path) * BTREE_ITER_MAX;

fs/bcachefs/btree_iter.h

@@ -227,7 +227,22 @@ static inline bool trans_was_restarted(struct btree_trans *trans, u32 restart_co
 	return restart_count != trans->restart_count;
 }
 
-void bch2_trans_verify_not_restarted(struct btree_trans *, u32);
+void __noreturn bch2_trans_restart_error(struct btree_trans *, u32);
+
+static inline void bch2_trans_verify_not_restarted(struct btree_trans *trans,
+						   u32 restart_count)
+{
+	if (trans_was_restarted(trans, restart_count))
+		bch2_trans_restart_error(trans, restart_count);
+}
+
+void __noreturn bch2_trans_in_restart_error(struct btree_trans *);
+
+static inline void bch2_trans_verify_not_in_restart(struct btree_trans *trans)
+{
+	if (trans->restarted)
+		bch2_trans_in_restart_error(trans);
+}
 
 __always_inline
 static inline int btree_trans_restart_nounlock(struct btree_trans *trans, int err)

fs/bcachefs/btree_update_leaf.c

@@ -1098,7 +1098,7 @@ int __bch2_trans_commit(struct btree_trans *trans)
 			goto err;
 	}
 retry:
-	EBUG_ON(trans->restarted);
+	bch2_trans_verify_not_in_restart(trans);
 	memset(&trans->journal_res, 0, sizeof(trans->journal_res));
 
 	ret = do_bch2_trans_commit(trans, &i, _RET_IP_);