bcachefs: bch2_btree_path_can_relock()

With the new assertions, we shouldn't be holding locks when
trans->locked is false, thus, we shouldn't use relock when we just want
to check if we can relock.

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

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 224001d8470d69c1d756251070e9ecf1f9e85dad..7718630625ed78ebbb086a931006ce7d45328796 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -1346,6 +1346,26 @@ static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t
        __clear_bit(path, trans->paths_allocated);
 }
 
+static bool bch2_btree_path_can_relock(struct btree_trans *trans, struct btree_path *path)
+{
+       unsigned l = path->level;
+
+       do {
+               if (!btree_path_node(path, l))
+                       break;
+
+               if (!is_btree_node(path, l))
+                       return false;
+
+               if (path->l[l].lock_seq != path->l[l].b->c.lock.seq)
+                       return false;
+
+               l++;
+       } while (l < path->locks_want);
+
+       return true;
+}
+
 void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent)
 {
        struct btree_path *path = trans->paths + path_idx, *dup;
@@ -1360,10 +1380,15 @@ void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool in
        if (!dup && !(!path->preserve && !is_btree_node(path, path->level)))
                return;
 
-       if (path->should_be_locked &&
-           !trans->restarted &&
-           (!dup || !bch2_btree_path_relock_norestart(trans, dup)))
-               return;
+       if (path->should_be_locked && !trans->restarted) {
+               if (!dup)
+                       return;
+
+               if (!(trans->locked
+                     ? bch2_btree_path_relock_norestart(trans, dup)
+                     : bch2_btree_path_can_relock(trans, dup)))
+                       return;
+       }
 
        if (dup) {
                dup->preserve           |= path->preserve;