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From:   Daniel Wagner <dwagner@suse.de>
To:     linux-nvme@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, Hannes Reinecke <hare@suse.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        Keith Busch <kbusch@kernel.org>,
        Ming Lei <ming.lei@redhat.com>,
        Wen Xiong <wenxiong@us.ibm.com>,
        Himanshu Madhani <himanshu.madhani@oracle.com>,
        James Smart <jsmart2021@gmail.com>,
        Daniel Wagner <dwagner@suse.de>
Subject: [PATCH v7 3/3] nvme-fc: Remove freeze/unfreeze around update_nr_hw_queues
Date:   Tue, 14 Sep 2021 11:20:08 +0200
Message-Id: <20210914092008.40370-4-dwagner@suse.de>
In-Reply-To: <20210914092008.40370-1-dwagner@suse.de>
References: <20210914092008.40370-1-dwagner@suse.de>
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From: James Smart <jsmart2021@gmail.com>

Remove the freeze/unfreeze around changes to the number of hardware
queues. Study and retest has indicated there are no ios that can be
active at this point so there is nothing to freeze.

nvme-fc is draining the queues in the shutdown and error recovery path
in __nvme_fc_abort_outstanding_ios.

This patch primarily reverts 88e837ed0f1f "nvme-fc: wait for queues to
freeze before calling update_hr_hw_queues". It's not an exact revert as
it leaves the adjusting of hw queues only if the count changes.

Signed-off-by: James Smart <jsmart2021@gmail.com>
[dwagner: added explanation why no IO is pending]
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/fc.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 6ebe68396712..aa14ad963d91 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2957,9 +2957,7 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 		dev_info(ctrl->ctrl.device,
 			"reconnect: revising io queue count from %d to %d\n",
 			prior_ioq_cnt, nr_io_queues);
-		nvme_wait_freeze(&ctrl->ctrl);
 		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
-		nvme_unfreeze(&ctrl->ctrl);
 	}
 
 	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
-- 
2.29.2