bcachefs: bch2_trans_relock() is trylock for lockdep

fix some spurious lockdep splats

Reported-by: syzbot+e088be3c2d5c05aaac35@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_iter.c

@@ -1007,7 +1007,7 @@ static int bch2_btree_path_traverse_all(struct btree_trans *trans)
 
 	bch2_trans_unlock(trans);
 	cond_resched();
-	trans_set_locked(trans);
+	trans_set_locked(trans, false);
 
 	if (unlikely(trans->memory_allocation_failure)) {
 		struct closure cl;
@@ -3248,7 +3248,7 @@ u32 bch2_trans_begin(struct btree_trans *trans)
 
 	trans->last_begin_ip = _RET_IP_;
 
-	trans_set_locked(trans);
+	trans_set_locked(trans, false);
 
 	if (trans->restarted) {
 		bch2_btree_path_traverse_all(trans);
@@ -3354,7 +3354,7 @@ struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx)
 	trans->srcu_idx		= srcu_read_lock(&c->btree_trans_barrier);
 	trans->srcu_lock_time	= jiffies;
 	trans->srcu_held	= true;
-	trans_set_locked(trans);
+	trans_set_locked(trans, false);
 
 	closure_init_stack_release(&trans->ref);
 	return trans;
@@ -3622,7 +3622,7 @@ int bch2_fs_btree_iter_init(struct bch_fs *c)
 #ifdef CONFIG_LOCKDEP
 	fs_reclaim_acquire(GFP_KERNEL);
 	struct btree_trans *trans = bch2_trans_get(c);
-	trans_set_locked(trans);
+	trans_set_locked(trans, false);
 	bch2_trans_put(trans);
 	fs_reclaim_release(GFP_KERNEL);
 #endif

fs/bcachefs/btree_locking.c

@@ -782,7 +782,7 @@ static inline int __bch2_trans_relock(struct btree_trans *trans, bool trace)
 			return bch2_trans_relock_fail(trans, path, &f, trace);
 	}
 
-	trans_set_locked(trans);
+	trans_set_locked(trans, true);
 out:
 	bch2_trans_verify_locks(trans);
 	return 0;

fs/bcachefs/btree_locking.h

@@ -188,10 +188,10 @@ int bch2_six_check_for_deadlock(struct six_lock *lock, void *p);
 
 /* lock: */
 
-static inline void trans_set_locked(struct btree_trans *trans)
+static inline void trans_set_locked(struct btree_trans *trans, bool try)
 {
 	if (!trans->locked) {
-		lock_acquire_exclusive(&trans->dep_map, 0, 0, NULL, _THIS_IP_);
+		lock_acquire_exclusive(&trans->dep_map, 0, try, NULL, _THIS_IP_);
 		trans->locked = true;
 		trans->last_unlock_ip = 0;