From 6bcd5089ee1302e9ad7072ca0866f0c5a1158359 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Nov 2022 16:00:42 +0100 Subject: [PATCH] nvme: don't unquiesce the admin queue in nvme_kill_queues None of the callers of nvme_kill_queues needs it to unquiesce the admin queues, as all of them already do it themselves: 1) nvme_reset_work explicit call nvme_start_admin_queue toward the beginning of the function. The extra call to nvme_start_admin_queue in nvme_reset_work this won't do anything as NVME_CTRL_ADMIN_Q_STOPPED will already be cleared. 2) nvme_remove calls nvme_dev_disable with shutdown flag set to true at the very beginning of the function if the PCIe device was not present, which is the precondition for the call to nvme_kill_queues. nvme_dev_disable already calls nvme_start_admin_queue toward the end of the function when the shutdown flag is set to true, so the admin queue is already enabled at this point. 3) nvme_remove_dead_ctrl schedules a workqueue to unbind the driver, which will end up in nvme_remove, which calls nvme_dev_disable with the shutdown flag. This case will call nvme_start_admin_queue a bit later than before. 4) apple_nvme_remove uses the same sequence as nvme_remove_dead_ctrl above. 5) nvme_remove_namespaces only calls nvme_kill_queues when the controller is in the DEAD state. That can only happen in the PCIe driver, and only from nvme_remove. See item 2) above for the conditions there. So it is safe to just remove the call to nvme_start_admin_queue in nvme_kill_queues without replacement. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20221101150050.3510-7-hch@lst.de Signed-off-by: Jens Axboe --- drivers/nvme/host/core.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 871a8ab7ec19..bb62803de5b2 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -5135,10 +5135,6 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) down_read(&ctrl->namespaces_rwsem); - /* Forcibly unquiesce queues to avoid blocking dispatch */ - if (ctrl->admin_q && !blk_queue_dying(ctrl->admin_q)) - nvme_start_admin_queue(ctrl); - list_for_each_entry(ns, &ctrl->namespaces, list) nvme_set_queue_dying(ns);