bcachefs: btree_iter->ip_allocated

In debug mode, we now track where btree iterators and paths are
initialized/allocated - helpful in tracking down btree path overflows.

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

fs/bcachefs/btree_iter.c

@@ -24,6 +24,15 @@ static inline void btree_path_list_remove(struct btree_trans *, struct btree_pat
 static inline void btree_path_list_add(struct btree_trans *, struct btree_path *,
 				       struct btree_path *);
 
+static inline unsigned long btree_iter_ip_allocated(struct btree_iter *iter)
+{
+#ifdef CONFIG_BCACHEFS_DEBUG
+	return iter->ip_allocated;
+#else
+	return 0;
+#endif
+}
+
 static struct btree_path *btree_path_alloc(struct btree_trans *, struct btree_path *);
 
 /*
@@ -1221,7 +1230,8 @@ static struct btree_path *btree_path_clone(struct btree_trans *trans, struct btr
 
 __flatten
 struct btree_path *__bch2_btree_path_make_mut(struct btree_trans *trans,
-			 struct btree_path *path, bool intent)
+			 struct btree_path *path, bool intent,
+			 unsigned long ip)
 {
 	__btree_path_put(path, intent);
 	path = btree_path_clone(trans, path, intent);
@@ -1231,15 +1241,15 @@ struct btree_path *__bch2_btree_path_make_mut(struct btree_trans *trans,
 
 struct btree_path * __must_check
 __bch2_btree_path_set_pos(struct btree_trans *trans,
-			  struct btree_path *path, struct bpos new_pos,
-			  bool intent, int cmp)
+		   struct btree_path *path, struct bpos new_pos,
+		   bool intent, unsigned long ip, int cmp)
 {
 	unsigned level = path->level;
 
 	EBUG_ON(trans->restarted);
 	EBUG_ON(!path->ref);
 
-	path = bch2_btree_path_make_mut(trans, path, intent);
+	path = bch2_btree_path_make_mut(trans, path, intent, ip);
 
 	path->pos		= new_pos;
 	trans->paths_sorted	= false;
@@ -1524,7 +1534,7 @@ static inline struct btree_path *btree_path_alloc(struct btree_trans *trans,
 struct btree_path *bch2_path_get(struct btree_trans *trans,
 				 enum btree_id btree_id, struct bpos pos,
 				 unsigned locks_want, unsigned level,
-				 unsigned flags)
+				 unsigned flags, unsigned long ip)
 {
 	struct btree_path *path, *path_pos = NULL;
 	bool cached = flags & BTREE_ITER_CACHED;
@@ -1552,7 +1562,7 @@ struct btree_path *bch2_path_get(struct btree_trans *trans,
 	    path_pos->btree_id	== btree_id &&
 	    path_pos->level	== level) {
 		__btree_path_get(path_pos, intent);
-		path = bch2_btree_path_set_pos(trans, path_pos, pos, intent);
+		path = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip);
 	} else {
 		path = btree_path_alloc(trans, path_pos);
 		path_pos = NULL;
@@ -1569,7 +1579,7 @@ struct btree_path *bch2_path_get(struct btree_trans *trans,
 		for (i = 0; i < ARRAY_SIZE(path->l); i++)
 			path->l[i].b		= ERR_PTR(-BCH_ERR_no_btree_node_init);
 #ifdef CONFIG_BCACHEFS_DEBUG
-		path->ip_allocated		= _RET_IP_;
+		path->ip_allocated		= ip;
 #endif
 		trans->paths_sorted		= false;
 	}
@@ -1651,7 +1661,8 @@ bch2_btree_iter_traverse(struct btree_iter *iter)
 
 	iter->path = bch2_btree_path_set_pos(iter->trans, iter->path,
 					btree_iter_search_key(iter),
-					iter->flags & BTREE_ITER_INTENT);
+					iter->flags & BTREE_ITER_INTENT,
+					btree_iter_ip_allocated(iter));
 
 	ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
 	if (ret)
@@ -1686,7 +1697,8 @@ struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
 	iter->k.p = iter->pos = b->key.k.p;
 
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
-					iter->flags & BTREE_ITER_INTENT);
+					iter->flags & BTREE_ITER_INTENT,
+					btree_iter_ip_allocated(iter));
 	btree_path_set_should_be_locked(iter->path);
 out:
 	bch2_btree_iter_verify_entry_exit(iter);
@@ -1740,7 +1752,8 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 		 */
 		path = iter->path =
 			bch2_btree_path_set_pos(trans, path, bpos_successor(iter->pos),
-					   iter->flags & BTREE_ITER_INTENT);
+					   iter->flags & BTREE_ITER_INTENT,
+					   btree_iter_ip_allocated(iter));
 
 		btree_path_set_level_down(trans, path, iter->min_depth);
 
@@ -1755,7 +1768,8 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 	iter->k.p = iter->pos = b->key.k.p;
 
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
-					iter->flags & BTREE_ITER_INTENT);
+					iter->flags & BTREE_ITER_INTENT,
+					btree_iter_ip_allocated(iter));
 	btree_path_set_should_be_locked(iter->path);
 	BUG_ON(iter->path->uptodate);
 out:
@@ -1907,10 +1921,12 @@ struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos
 		iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos,
 						     iter->flags & BTREE_ITER_INTENT, 0,
 						     iter->flags|BTREE_ITER_CACHED|
-						     BTREE_ITER_CACHED_NOFILL);
+						     BTREE_ITER_CACHED_NOFILL,
+						     _THIS_IP_);
 
 	iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos,
-					iter->flags & BTREE_ITER_INTENT);
+					iter->flags & BTREE_ITER_INTENT,
+					btree_iter_ip_allocated(iter));
 
 	ret =   bch2_btree_path_traverse(trans, iter->key_cache_path,
 					 iter->flags|BTREE_ITER_CACHED) ?:
@@ -1942,7 +1958,8 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
 		struct btree_path_level *l;
 
 		iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
-					iter->flags & BTREE_ITER_INTENT);
+					iter->flags & BTREE_ITER_INTENT,
+					btree_iter_ip_allocated(iter));
 
 		ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
 		if (unlikely(ret)) {
@@ -2092,7 +2109,8 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 
 			iter->update_path = bch2_btree_path_set_pos(trans,
 						iter->update_path, pos,
-						iter->flags & BTREE_ITER_INTENT);
+						iter->flags & BTREE_ITER_INTENT,
+						_THIS_IP_);
 			ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags);
 			if (unlikely(ret)) {
 				k = bkey_s_c_err(ret);
@@ -2124,7 +2142,8 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 	iter->pos = iter_pos;
 
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p,
-				iter->flags & BTREE_ITER_INTENT);
+				iter->flags & BTREE_ITER_INTENT,
+				btree_iter_ip_allocated(iter));
 
 	btree_path_set_should_be_locked(iter->path);
 out_no_locked:
@@ -2170,7 +2189,8 @@ struct bkey_s_c bch2_btree_iter_peek_all_levels(struct btree_iter *iter)
 
 	while (1) {
 		iter->path = bch2_btree_path_set_pos(trans, iter->path, iter->pos,
-					iter->flags & BTREE_ITER_INTENT);
+					iter->flags & BTREE_ITER_INTENT,
+					btree_iter_ip_allocated(iter));
 
 		ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
 		if (unlikely(ret)) {
@@ -2283,7 +2303,8 @@ struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
 
 	while (1) {
 		iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
-						iter->flags & BTREE_ITER_INTENT);
+						iter->flags & BTREE_ITER_INTENT,
+						btree_iter_ip_allocated(iter));
 
 		ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
 		if (unlikely(ret)) {
@@ -2413,7 +2434,8 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
 
 	search_key = btree_iter_search_key(iter);
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
-					iter->flags & BTREE_ITER_INTENT);
+					iter->flags & BTREE_ITER_INTENT,
+					btree_iter_ip_allocated(iter));
 
 	ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
 	if (unlikely(ret)) {
@@ -2678,7 +2700,8 @@ static inline void bch2_trans_iter_init_inlined(struct btree_trans *trans,
 			  unsigned flags)
 {
 	bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
-			       bch2_btree_iter_flags(trans, btree_id, flags));
+			       bch2_btree_iter_flags(trans, btree_id, flags),
+			       _RET_IP_);
 }
 
 void bch2_trans_iter_init_outlined(struct btree_trans *trans,
@@ -2687,7 +2710,8 @@ void bch2_trans_iter_init_outlined(struct btree_trans *trans,
 			  unsigned flags)
 {
 	bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
-			       bch2_btree_iter_flags(trans, btree_id, flags));
+			       bch2_btree_iter_flags(trans, btree_id, flags),
+			       _RET_IP_);
 }
 
 void bch2_trans_node_iter_init(struct btree_trans *trans,
@@ -2703,7 +2727,8 @@ void bch2_trans_node_iter_init(struct btree_trans *trans,
        flags |= BTREE_ITER_ALL_SNAPSHOTS;
 
 	bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth,
-			       __bch2_btree_iter_flags(trans, btree_id, flags));
+			       __bch2_btree_iter_flags(trans, btree_id, flags),
+			       _RET_IP_);
 
 	iter->min_depth	= depth;
 

fs/bcachefs/btree_iter.h

@@ -144,39 +144,40 @@ __trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
 	     _path = __trans_next_path_with_node((_trans), (_b),	\
 						 (_path)->idx + 1))
 
-struct btree_path *__bch2_btree_path_make_mut(struct btree_trans *,
-					      struct btree_path *, bool);
+struct btree_path *__bch2_btree_path_make_mut(struct btree_trans *, struct btree_path *,
+			 bool, unsigned long);
 
 static inline struct btree_path * __must_check
 bch2_btree_path_make_mut(struct btree_trans *trans,
-			 struct btree_path *path, bool intent)
+			 struct btree_path *path, bool intent,
+			 unsigned long ip)
 {
 	if (path->ref > 1 || path->preserve)
-		path = __bch2_btree_path_make_mut(trans, path, intent);
+		path = __bch2_btree_path_make_mut(trans, path, intent, ip);
 	path->should_be_locked = false;
 	return path;
 }
 
 struct btree_path * __must_check
 __bch2_btree_path_set_pos(struct btree_trans *, struct btree_path *,
-			  struct bpos, bool, int);
+			struct bpos, bool, unsigned long, int);
 
 static inline struct btree_path * __must_check
 bch2_btree_path_set_pos(struct btree_trans *trans,
 		   struct btree_path *path, struct bpos new_pos,
-		   bool intent)
+		   bool intent, unsigned long ip)
 {
 	int cmp = bpos_cmp(new_pos, path->pos);
 
 	return cmp
-		? __bch2_btree_path_set_pos(trans, path, new_pos, intent, cmp)
+		? __bch2_btree_path_set_pos(trans, path, new_pos, intent, ip, cmp)
 		: path;
 }
 
 int __must_check bch2_btree_path_traverse(struct btree_trans *,
 					  struct btree_path *, unsigned);
 struct btree_path *bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
-				 unsigned, unsigned, unsigned);
+				 unsigned, unsigned, unsigned, unsigned long);
 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 
 struct bkey_i *bch2_btree_journal_peek_slot(struct btree_trans *,
@@ -359,7 +360,8 @@ static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
 					  unsigned btree_id, struct bpos pos,
 					  unsigned locks_want,
 					  unsigned depth,
-					  unsigned flags)
+					  unsigned flags,
+					  unsigned long ip)
 {
 	memset(iter, 0, sizeof(*iter));
 	iter->trans	= trans;
@@ -369,8 +371,11 @@ static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
 	iter->pos	= pos;
 	iter->k.p	= pos;
 
+#ifdef CONFIG_BCACHEFS_DEBUG
+	iter->ip_allocated = ip;
+#endif
 	iter->path = bch2_path_get(trans, btree_id, iter->pos,
-				   locks_want, depth, flags);
+				   locks_want, depth, flags, ip);
 }
 
 void bch2_trans_iter_init_outlined(struct btree_trans *, struct btree_iter *,
@@ -384,7 +389,8 @@ static inline void bch2_trans_iter_init(struct btree_trans *trans,
 	if (__builtin_constant_p(btree_id) &&
 	    __builtin_constant_p(flags))
 		bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
-				bch2_btree_iter_flags(trans, btree_id, flags));
+				bch2_btree_iter_flags(trans, btree_id, flags),
+				_THIS_IP_);
 	else
 		bch2_trans_iter_init_outlined(trans, iter, btree_id, pos, flags);
 }

fs/bcachefs/btree_types.h

@@ -289,6 +289,9 @@ struct btree_iter {
 	/* BTREE_ITER_WITH_JOURNAL: */
 	size_t			journal_idx;
 	struct bpos		journal_pos;
+#ifdef CONFIG_BCACHEFS_DEBUG
+	unsigned long		ip_allocated;
+#endif
 };
 
 struct btree_key_cache_freelist {

fs/bcachefs/btree_update_interior.c

@@ -36,8 +36,9 @@ static struct btree_path *get_unlocked_mut_path(struct btree_trans *trans,
 	struct btree_path *path;
 
 	path = bch2_path_get(trans, btree_id, pos, level + 1, level,
-			     BTREE_ITER_NOPRESERVE|BTREE_ITER_INTENT);
-	path = bch2_btree_path_make_mut(trans, path, true);
+			     BTREE_ITER_NOPRESERVE|
+			     BTREE_ITER_INTENT, _RET_IP_);
+	path = bch2_btree_path_make_mut(trans, path, true, _RET_IP_);
 	bch2_btree_path_downgrade(trans, path);
 	__bch2_btree_path_unlock(trans, path);
 	return path;
@@ -1780,7 +1781,7 @@ int __bch2_foreground_maybe_merge(struct btree_trans *trans,
 		: bpos_successor(b->data->max_key);
 
 	sib_path = bch2_path_get(trans, path->btree_id, sib_pos,
-				 U8_MAX, level, BTREE_ITER_INTENT);
+				 U8_MAX, level, BTREE_ITER_INTENT, _THIS_IP_);
 	ret = bch2_btree_path_traverse(trans, sib_path, false);
 	if (ret)
 		goto err;
@@ -2093,7 +2094,8 @@ static int __bch2_btree_node_update_key(struct btree_trans *trans,
 		bch2_trans_copy_iter(&iter2, iter);
 
 		iter2.path = bch2_btree_path_make_mut(trans, iter2.path,
-				iter2.flags & BTREE_ITER_INTENT);
+				iter2.flags & BTREE_ITER_INTENT,
+				_THIS_IP_);
 
 		BUG_ON(iter2.path->level != b->c.level);
 		BUG_ON(!bpos_eq(iter2.path->pos, new_key->k.p));

fs/bcachefs/btree_update_leaf.c

@@ -1452,7 +1452,7 @@ static noinline int flush_new_cached_update(struct btree_trans *trans,
 	i->flags |= BTREE_TRIGGER_NORUN;
 
 	btree_path = bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
-				   BTREE_ITER_INTENT);
+				   BTREE_ITER_INTENT, _THIS_IP_);
 
 	ret = bch2_btree_path_traverse(trans, btree_path, 0);
 	if (ret)
@@ -1590,11 +1590,13 @@ int __must_check bch2_trans_update(struct btree_trans *trans, struct btree_iter
 			if (!iter->key_cache_path)
 				iter->key_cache_path =
 					bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
-						      BTREE_ITER_INTENT|BTREE_ITER_CACHED);
+						      BTREE_ITER_INTENT|
+						      BTREE_ITER_CACHED, _THIS_IP_);
 
 			iter->key_cache_path =
 				bch2_btree_path_set_pos(trans, iter->key_cache_path, path->pos,
-							iter->flags & BTREE_ITER_INTENT);
+							iter->flags & BTREE_ITER_INTENT,
+							_THIS_IP_);
 
 			ret = bch2_btree_path_traverse(trans, iter->key_cache_path,
 						       BTREE_ITER_CACHED);