bcachefs: bch2_path_get() -> btree_path_idx_t

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

fs/bcachefs/btree_iter.c

@@ -1547,7 +1547,7 @@ static inline struct btree_path *btree_path_alloc(struct btree_trans *trans,
 	return path;
 }
 
-struct btree_path *bch2_path_get(struct btree_trans *trans,
+btree_path_idx_t bch2_path_get(struct btree_trans *trans,
 			     enum btree_id btree_id, struct bpos pos,
 			     unsigned locks_want, unsigned level,
 			     unsigned flags, unsigned long ip)
@@ -1618,7 +1618,7 @@ struct btree_path *bch2_path_get(struct btree_trans *trans,
 	if (locks_want > path->locks_want)
 		bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL);
 
-	return path;
+	return path->idx;
 }
 
 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u)
@@ -1928,7 +1928,7 @@ struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos
 		return bkey_s_c_null;
 
 	if (!iter->key_cache_path)
-		iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos,
+		iter->key_cache_path = trans->paths + bch2_path_get(trans, iter->btree_id, pos,
 						     iter->flags & BTREE_ITER_INTENT, 0,
 						     iter->flags|BTREE_ITER_CACHED|
 						     BTREE_ITER_CACHED_NOFILL,

fs/bcachefs/btree_iter.h

@@ -202,7 +202,7 @@ static inline int __must_check bch2_btree_path_traverse(struct btree_trans *tran
 
 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,
+btree_path_idx_t bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
 			       unsigned, unsigned, unsigned, unsigned long);
 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 
@@ -443,7 +443,7 @@ static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
 #ifdef CONFIG_BCACHEFS_DEBUG
 	iter->ip_allocated = ip;
 #endif
-	iter->path = bch2_path_get(trans, btree_id, iter->pos,
+	iter->path = trans->paths + bch2_path_get(trans, btree_id, iter->pos,
 				   locks_want, depth, flags, ip);
 }
 

fs/bcachefs/btree_types.h

@@ -222,6 +222,8 @@ enum btree_path_uptodate {
 #define TRACK_PATH_ALLOCATED
 #endif
 
+typedef u16 btree_path_idx_t;
+
 struct btree_path {
 	u8			idx;
 	u8			sorted_idx;

fs/bcachefs/btree_update.c

@@ -344,16 +344,18 @@ static noinline int flush_new_cached_update(struct btree_trans *trans,
 					    enum btree_update_flags flags,
 					    unsigned long ip)
 {
-	struct btree_path *btree_path;
 	struct bkey k;
 	int ret;
 
-	btree_path = bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
+	btree_path_idx_t path_idx =
+		bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
 			      BTREE_ITER_INTENT, _THIS_IP_);
-	ret = bch2_btree_path_traverse(trans, btree_path, 0);
+	ret = bch2_btree_path_traverse(trans, trans->paths + path_idx, 0);
 	if (ret)
 		goto out;
 
+	struct btree_path *btree_path = trans->paths + path_idx;
+
 	/*
 	 * The old key in the insert entry might actually refer to an existing
 	 * key in the btree that has been deleted from cache and not yet
@@ -467,7 +469,7 @@ static noinline int bch2_trans_update_get_key_cache(struct btree_trans *trans,
 		int ret;
 
 		if (!iter->key_cache_path)
-			iter->key_cache_path =
+			iter->key_cache_path = trans->paths +
 				bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
 					      BTREE_ITER_INTENT|
 					      BTREE_ITER_CACHED, _THIS_IP_);

fs/bcachefs/btree_update_interior.c

@@ -36,7 +36,7 @@ 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,
+	path = trans->paths + bch2_path_get(trans, btree_id, pos, level + 1, level,
 			     BTREE_ITER_NOPRESERVE|
 			     BTREE_ITER_INTENT, _RET_IP_);
 	path = bch2_btree_path_make_mut(trans, path, true, _RET_IP_);
@@ -1795,7 +1795,7 @@ int __bch2_foreground_maybe_merge(struct btree_trans *trans,
 		? bpos_predecessor(b->data->min_key)
 		: bpos_successor(b->data->max_key);
 
-	sib_path = bch2_path_get(trans, path->btree_id, sib_pos,
+	sib_path = trans->paths + bch2_path_get(trans, path->btree_id, sib_pos,
 				 U8_MAX, level, BTREE_ITER_INTENT, _THIS_IP_);
 	ret = bch2_btree_path_traverse(trans, sib_path, false);
 	if (ret)