diff options
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/drbd/drbd_worker.c | 48 |
1 files changed, 15 insertions, 33 deletions
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 34dde10fae48..d8f57b6305cd 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -1799,34 +1799,6 @@ void drbd_start_resync(struct drbd_device *device, enum drbd_conns side) mutex_unlock(device->state_mutex); } -/* If the resource already closed the current epoch, but we did not - * (because we have not yet seen new requests), we should send the - * corresponding barrier now. Must be checked within the same spinlock - * that is used to check for new requests. */ -static bool need_to_send_barrier(struct drbd_connection *connection) -{ - if (!connection->send.seen_any_write_yet) - return false; - - /* Skip barriers that do not contain any writes. - * This may happen during AHEAD mode. */ - if (!connection->send.current_epoch_writes) - return false; - - /* ->req_lock is held when requests are queued on - * connection->sender_work, and put into ->transfer_log. - * It is also held when ->current_tle_nr is increased. - * So either there are already new requests queued, - * and corresponding barriers will be send there. - * Or nothing new is queued yet, so the difference will be 1. - */ - if (atomic_read(&connection->current_tle_nr) != - connection->send.current_epoch_nr + 1) - return false; - - return true; -} - static bool dequeue_work_batch(struct drbd_work_queue *queue, struct list_head *work_list) { spin_lock_irq(&queue->q_lock); @@ -1885,12 +1857,22 @@ static void wait_for_work(struct drbd_connection *connection, struct list_head * spin_unlock_irq(&connection->resource->req_lock); break; } - send_barrier = need_to_send_barrier(connection); + + /* We found nothing new to do, no to-be-communicated request, + * no other work item. We may still need to close the last + * epoch. Next incoming request epoch will be connection -> + * current transfer log epoch number. If that is different + * from the epoch of the last request we communicated, it is + * safe to send the epoch separating barrier now. + */ + send_barrier = + atomic_read(&connection->current_tle_nr) != + connection->send.current_epoch_nr; spin_unlock_irq(&connection->resource->req_lock); - if (send_barrier) { - drbd_send_barrier(connection); - connection->send.current_epoch_nr++; - } + + if (send_barrier) + maybe_send_barrier(connection, + connection->send.current_epoch_nr + 1); schedule(); /* may be woken up for other things but new work, too, * e.g. if the current epoch got closed. |