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From:   Daniel Wagner <dwagner@suse.de>
To:     linux-nvme@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org,
        James Smart <james.smart@broadcom.com>,
        Keith Busch <kbusch@kernel.org>,
        Ming Lei <ming.lei@redhat.com>,
        Sagi Grimberg <sagi@grimberg.me>,
        Hannes Reinecke <hare@suse.de>,
        Wen Xiong <wenxiong@us.ibm.com>,
        Himanshu Madhani <himanshu.madhani@oracle.com>,
        Daniel Wagner <dwagner@suse.de>,
        James Smart <jsmart2021@gmail.com>
Subject: [PATCH v6 1/3] nvme-fc: Update hardware queues before using them
Date:   Mon, 23 Aug 2021 13:23:49 +0200
Message-Id: <20210823112351.82899-2-dwagner@suse.de>
In-Reply-To: <20210823112351.82899-1-dwagner@suse.de>
References: <20210823112351.82899-1-dwagner@suse.de>
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In case the number of hardware queues changes, we need to update the
tagset and the mapping of ctx to hctx first.

If we try to create and connect the I/O queues first, this operation
will fail (target will reject the connect call due to the wrong number
of queues) and hence we bail out of the recreate function. Then we
will to try the very same operation again, thus we don't make any
progress.

Reviewed-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/fc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 7f462af1b02a..8a903769364f 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2951,14 +2951,6 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 	if (ctrl->ctrl.queue_count == 1)
 		return 0;
 
-	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
-	if (ret)
-		goto out_free_io_queues;
-
-	ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
-	if (ret)
-		goto out_delete_hw_queues;
-
 	if (prior_ioq_cnt != nr_io_queues) {
 		dev_info(ctrl->ctrl.device,
 			"reconnect: revising io queue count from %d to %d\n",
@@ -2968,6 +2960,14 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 		nvme_unfreeze(&ctrl->ctrl);
 	}
 
+	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
+	if (ret)
+		goto out_free_io_queues;
+
+	ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
+	if (ret)
+		goto out_delete_hw_queues;
+
 	return 0;
 
 out_delete_hw_queues:
-- 
2.29.2