bcachefs: More drop_locks_do() conversions

Using drop_locks_do() ensures that every unlock() is paired with a
relock(), with proper error checking.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_iter.c

@@ -2892,9 +2892,7 @@ u32 bch2_trans_begin(struct btree_trans *trans)
 	if (!trans->restarted &&
 	    (need_resched() ||
 	     now - trans->last_begin_time > BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS)) {
-		bch2_trans_unlock(trans);
-		cond_resched();
-		bch2_trans_relock(trans);
+		drop_locks_do(trans, (cond_resched(), 0));
 		now = local_clock();
 	}
 	trans->last_begin_time = now;

fs/bcachefs/btree_update_interior.c

@@ -1126,23 +1126,19 @@ bch2_btree_update_start(struct btree_trans *trans, struct btree_path *path,
 				      BTREE_UPDATE_JOURNAL_RES,
 				      journal_flags|JOURNAL_RES_GET_NONBLOCK);
 	if (ret) {
-		bch2_trans_unlock(trans);
-
 		if (flags & BTREE_INSERT_JOURNAL_RECLAIM) {
 			ret = -BCH_ERR_journal_reclaim_would_deadlock;
 			goto err;
 		}
 
-		ret = bch2_journal_preres_get(&c->journal, &as->journal_preres,
+		ret = drop_locks_do(trans,
+			bch2_journal_preres_get(&c->journal, &as->journal_preres,
 					      BTREE_UPDATE_JOURNAL_RES,
-					      journal_flags);
-		if (ret) {
+					      journal_flags));
+		if (ret == -BCH_ERR_journal_preres_get_blocked) {
 			trace_and_count(c, trans_restart_journal_preres_get, trans, _RET_IP_, journal_flags);
 			ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_journal_preres_get);
-			goto err;
 		}
-
-		ret = bch2_trans_relock(trans);
 		if (ret)
 			goto err;
 	}

fs/bcachefs/btree_update_leaf.c

@@ -947,34 +947,20 @@ int bch2_trans_commit_error(struct btree_trans *trans, unsigned flags,
 			trace_and_count(c, trans_restart_btree_node_split, trans, trace_ip, i->path);
 		break;
 	case -BCH_ERR_btree_insert_need_mark_replicas:
-		bch2_trans_unlock(trans);
-
-		ret = bch2_replicas_delta_list_mark(c, trans->fs_usage_deltas);
-		if (ret)
-			break;
-
-		ret = bch2_trans_relock(trans);
-		if (ret)
-			trace_and_count(c, trans_restart_mark_replicas, trans, trace_ip);
+		ret = drop_locks_do(trans,
+			bch2_replicas_delta_list_mark(c, trans->fs_usage_deltas));
 		break;
 	case -BCH_ERR_journal_res_get_blocked:
-		bch2_trans_unlock(trans);
-
 		if ((flags & BTREE_INSERT_JOURNAL_RECLAIM) &&
 		    !(flags & JOURNAL_WATERMARK_reserved)) {
 			ret = -BCH_ERR_journal_reclaim_would_deadlock;
 			break;
 		}
 
-		ret = bch2_trans_journal_res_get(trans,
+		ret = drop_locks_do(trans,
+			bch2_trans_journal_res_get(trans,
 					(flags & JOURNAL_WATERMARK_MASK)|
-					JOURNAL_RES_GET_CHECK);
-		if (ret)
-			break;
-
-		ret = bch2_trans_relock(trans);
-		if (ret)
-			trace_and_count(c, trans_restart_journal_res_get, trans, trace_ip);
+					JOURNAL_RES_GET_CHECK));
 		break;
 	case -BCH_ERR_btree_insert_need_journal_reclaim:
 		bch2_trans_unlock(trans);
@@ -987,8 +973,6 @@ int bch2_trans_commit_error(struct btree_trans *trans, unsigned flags,
 			break;
 
 		ret = bch2_trans_relock(trans);
-		if (ret)
-			trace_and_count(c, trans_restart_journal_reclaim, trans, trace_ip);
 		break;
 	case -BCH_ERR_btree_insert_need_flush_buffer: {
 		struct btree_write_buffer *wb = &c->btree_write_buffer;
@@ -996,20 +980,20 @@ int bch2_trans_commit_error(struct btree_trans *trans, unsigned flags,
 		ret = 0;
 
 		if (wb->state.nr > wb->size * 3 / 4) {
-			bch2_trans_reset_updates(trans);
 			bch2_trans_unlock(trans);
-
 			mutex_lock(&wb->flush_lock);
 
-			if (wb->state.nr > wb->size * 3 / 4)
+			if (wb->state.nr > wb->size * 3 / 4) {
+				bch2_trans_begin(trans);
 				ret = __bch2_btree_write_buffer_flush(trans,
 						flags|BTREE_INSERT_NOCHECK_RW, true);
-			else
+				if (!ret) {
+					trace_and_count(c, trans_restart_write_buffer_flush, trans, _THIS_IP_);
+					ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_write_buffer_flush);
+				}
+			} else {
 				mutex_unlock(&wb->flush_lock);
-
-			if (!ret) {
-				trace_and_count(c, trans_restart_write_buffer_flush, trans, _THIS_IP_);
-				ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_write_buffer_flush);
+				ret = bch2_trans_relock(trans);
 			}
 		}
 		break;

fs/bcachefs/trace.h

@@ -905,13 +905,6 @@ DEFINE_EVENT(transaction_event,	trans_blocked_journal_reclaim,
 	TP_ARGS(trans, caller_ip)
 );
 
-DEFINE_EVENT(transaction_event,	trans_restart_journal_res_get,
-	TP_PROTO(struct btree_trans *trans,
-		 unsigned long caller_ip),
-	TP_ARGS(trans, caller_ip)
-);
-
-
 TRACE_EVENT(trans_restart_journal_preres_get,
 	TP_PROTO(struct btree_trans *trans,
 		 unsigned long caller_ip,
@@ -935,12 +928,6 @@ TRACE_EVENT(trans_restart_journal_preres_get,
 		  __entry->flags)
 );
 
-DEFINE_EVENT(transaction_event,	trans_restart_journal_reclaim,
-	TP_PROTO(struct btree_trans *trans,
-		 unsigned long caller_ip),
-	TP_ARGS(trans, caller_ip)
-);
-
 DEFINE_EVENT(transaction_event,	trans_restart_fault_inject,
 	TP_PROTO(struct btree_trans *trans,
 		 unsigned long caller_ip),
@@ -953,12 +940,6 @@ DEFINE_EVENT(transaction_event,	trans_traverse_all,
 	TP_ARGS(trans, caller_ip)
 );
 
-DEFINE_EVENT(transaction_event,	trans_restart_mark_replicas,
-	TP_PROTO(struct btree_trans *trans,
-		 unsigned long caller_ip),
-	TP_ARGS(trans, caller_ip)
-);
-
 DEFINE_EVENT(transaction_event,	trans_restart_key_cache_raced,
 	TP_PROTO(struct btree_trans *trans,
 		 unsigned long caller_ip),