From: Sagi Grimberg <sagi@grimberg.me>
Date: Fri, 2 Aug 2019 19:33:59 -0700
Subject: [PATCH] nvme: make fabrics command run on a separate request queue
Patch-mainline: v5.4-rc1
Git-commit: e7832cb48a654cd12b2bc9181b2f0ad49d526ac6
References: bsc#1181161

We have a fundamental issue that fabric commands use the admin_q.
The reason is, that admin-connect, register reads and writes and
admin commands cannot be guaranteed ordering while we are running
controller resets.

For example, when we reset a controller we perform:
1. disable the controller
2. teardown the admin queue
3. re-establish the admin queue
4. enable the controller

In order to perform (3), we need to unquiesce the admin queue, however
we may have some admin commands that are already pending on the
quiesced admin_q and will immediate execute when we unquiesce it before
we execute (4). The host must not send admin commands to the controller
before enabling the controller.

To fix this, we have the fabric commands (admin connect and property
get/set, but not I/O queue connect) use a separate fabrics_q and make
sure to quiesce the admin_q before we disable the controller, and
unquiesce it only after we enable the controller.

This fixes the error prints from nvmet in a controller reset storm test:
kernel: nvmet: got cmd 6 while CC.EN == 0 on qid = 0
Which indicate that the host is sending an admin command when the
controller is not enabled.

Reviewed-by:  James Smart <james.smart@broadcom.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
 drivers/nvme/host/fabrics.c |  8 ++++----
 drivers/nvme/host/fc.c      | 15 ++++++++++++---
 drivers/nvme/host/nvme.h    |  1 +
 drivers/nvme/host/rdma.c    | 19 +++++++++++++++++--
 drivers/nvme/host/tcp.c     | 19 +++++++++++++++++--
 drivers/nvme/target/loop.c  | 16 +++++++++++++---
 6 files changed, 64 insertions(+), 14 deletions(-)

--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -158,7 +158,7 @@ int nvmf_reg_read32(struct nvme_ctrl *ct
 	cmd.prop_get.fctype = nvme_fabrics_type_property_get;
 	cmd.prop_get.offset = cpu_to_le32(off);
 
-	ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, &res, NULL, 0, 0,
+	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, &res, NULL, 0, 0,
 			NVME_QID_ANY, 0, 0);
 
 	if (ret >= 0)
@@ -205,7 +205,7 @@ int nvmf_reg_read64(struct nvme_ctrl *ct
 	cmd.prop_get.attrib = 1;
 	cmd.prop_get.offset = cpu_to_le32(off);
 
-	ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, &res, NULL, 0, 0,
+	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, &res, NULL, 0, 0,
 			NVME_QID_ANY, 0, 0);
 
 	if (ret >= 0)
@@ -251,7 +251,7 @@ int nvmf_reg_write32(struct nvme_ctrl *c
 	cmd.prop_set.offset = cpu_to_le32(off);
 	cmd.prop_set.value = cpu_to_le64(val);
 
-	ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, NULL, NULL, 0, 0,
+	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, NULL, NULL, 0, 0,
 			NVME_QID_ANY, 0, 0);
 	if (unlikely(ret))
 		dev_err(ctrl->device,
@@ -404,7 +404,7 @@ int nvmf_connect_admin_queue(struct nvme
 	strncpy(data->subsysnqn, ctrl->opts->subsysnqn, NVMF_NQN_SIZE);
 	strncpy(data->hostnqn, ctrl->opts->host->nqn, NVMF_NQN_SIZE);
 
-	ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, &res,
+	ret = __nvme_submit_sync_cmd(ctrl->fabrics_q, &cmd, &res,
 			data, sizeof(*data), 0, NVME_QID_ANY, 1,
 			BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
 	if (ret) {
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2018,6 +2018,7 @@ nvme_fc_ctrl_free(struct kref *ref)
 
 	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 	blk_cleanup_queue(ctrl->ctrl.admin_q);
+	blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 	blk_mq_free_tag_set(&ctrl->admin_tag_set);
 
 	kfree(ctrl->queues);
@@ -2650,8 +2651,6 @@ nvme_fc_create_association(struct nvme_f
 	if (ret)
 		goto out_delete_hw_queue;
 
-	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
-
 	ret = nvmf_connect_admin_queue(&ctrl->ctrl);
 	if (ret)
 		goto out_disconnect_admin_queue;
@@ -2682,6 +2681,8 @@ nvme_fc_create_association(struct nvme_f
 	ctrl->ctrl.max_hw_sectors =
 		(ctrl->lport->ops->max_sgl_segments - 1) << (PAGE_SHIFT - 9);
 
+	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
+
 	ret = nvme_init_identify(&ctrl->ctrl);
 	if (ret)
 		goto out_disconnect_admin_queue;
@@ -3125,10 +3126,16 @@ nvme_fc_init_ctrl(struct device *dev, st
 		goto out_free_queues;
 	ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 
+	ctrl->ctrl.fabrics_q = blk_mq_init_queue(&ctrl->admin_tag_set);
+	if (IS_ERR(ctrl->ctrl.fabrics_q)) {
+		ret = PTR_ERR(ctrl->ctrl.fabrics_q);
+		goto out_free_admin_tag_set;
+	}
+
 	ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 	if (IS_ERR(ctrl->ctrl.admin_q)) {
 		ret = PTR_ERR(ctrl->ctrl.admin_q);
-		goto out_free_admin_tag_set;
+		goto out_cleanup_fabrics_q;
 	}
 
 	/*
@@ -3200,6 +3207,8 @@ fail_ctrl:
 
 out_cleanup_admin_q:
 	blk_cleanup_queue(ctrl->ctrl.admin_q);
+out_cleanup_fabrics_q:
+	blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 out_free_admin_tag_set:
 	blk_mq_free_tag_set(&ctrl->admin_tag_set);
 out_free_queues:
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -158,6 +158,7 @@ struct nvme_ctrl {
 	const struct nvme_ctrl_ops *ops;
 	struct request_queue *admin_q;
 	struct request_queue *connect_q;
+	struct request_queue *fabrics_q;
 	struct device *dev;
 	int instance;
 	int numa_node;
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -721,6 +721,7 @@ static void nvme_rdma_destroy_admin_queu
 {
 	if (remove) {
 		blk_cleanup_queue(ctrl->ctrl.admin_q);
+		blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 		blk_mq_free_tag_set(ctrl->ctrl.admin_tagset);
 	}
 	if (ctrl->async_event_sqe.data) {
@@ -762,10 +763,16 @@ static int nvme_rdma_configure_admin_que
 			goto out_free_async_qe;
 		}
 
+		ctrl->ctrl.fabrics_q = blk_mq_init_queue(&ctrl->admin_tag_set);
+		if (IS_ERR(ctrl->ctrl.fabrics_q)) {
+			error = PTR_ERR(ctrl->ctrl.fabrics_q);
+			goto out_free_tagset;
+		}
+
 		ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 		if (IS_ERR(ctrl->ctrl.admin_q)) {
 			error = PTR_ERR(ctrl->ctrl.admin_q);
-			goto out_free_tagset;
+			goto out_cleanup_fabrics_q;
 		}
 	}
 
@@ -791,6 +798,8 @@ static int nvme_rdma_configure_admin_que
 	ctrl->ctrl.max_hw_sectors =
 		(ctrl->max_fr_pages - 1) << (ilog2(SZ_4K) - 9);
 
+	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
+
 	error = nvme_init_identify(&ctrl->ctrl);
 	if (error)
 		goto out_stop_queue;
@@ -802,6 +811,9 @@ out_stop_queue:
 out_cleanup_queue:
 	if (new)
 		blk_cleanup_queue(ctrl->ctrl.admin_q);
+out_cleanup_fabrics_q:
+	if (new)
+		blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 out_free_tagset:
 	if (new)
 		blk_mq_free_tag_set(ctrl->ctrl.admin_tagset);
@@ -876,7 +888,8 @@ static void nvme_rdma_teardown_admin_que
 			nvme_cancel_request, &ctrl->ctrl);
 		blk_mq_tagset_wait_completed_request(ctrl->ctrl.admin_tagset);
 	}
-	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
+	if (remove)
+		blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 	nvme_rdma_destroy_admin_queue(ctrl, remove);
 }
 
@@ -1035,6 +1048,7 @@ static void nvme_rdma_error_recovery_wor
 	nvme_rdma_teardown_io_queues(ctrl, false);
 	nvme_start_queues(&ctrl->ctrl);
 	nvme_rdma_teardown_admin_queue(ctrl, false);
+	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 
 	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
 		/* state change failure is ok if we're in DELETING state */
@@ -1827,6 +1841,7 @@ static const struct blk_mq_ops nvme_rdma
 static void nvme_rdma_shutdown_ctrl(struct nvme_rdma_ctrl *ctrl, bool shutdown)
 {
 	nvme_rdma_teardown_io_queues(ctrl, shutdown);
+	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 	if (shutdown)
 		nvme_shutdown_ctrl(&ctrl->ctrl);
 	else
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1636,6 +1636,7 @@ static void nvme_tcp_destroy_admin_queue
 	if (remove) {
 		free_opal_dev(ctrl->opal_dev);
 		blk_cleanup_queue(ctrl->admin_q);
+		blk_cleanup_queue(ctrl->fabrics_q);
 		blk_mq_free_tag_set(ctrl->admin_tagset);
 	}
 	nvme_tcp_free_admin_queue(ctrl);
@@ -1656,10 +1657,16 @@ static int nvme_tcp_configure_admin_queu
 			goto out_free_queue;
 		}
 
+		ctrl->fabrics_q = blk_mq_init_queue(ctrl->admin_tagset);
+		if (IS_ERR(ctrl->fabrics_q)) {
+			error = PTR_ERR(ctrl->fabrics_q);
+			goto out_free_tagset;
+		}
+
 		ctrl->admin_q = blk_mq_init_queue(ctrl->admin_tagset);
 		if (IS_ERR(ctrl->admin_q)) {
 			error = PTR_ERR(ctrl->admin_q);
-			goto out_free_tagset;
+			goto out_cleanup_fabrics_q;
 		}
 	}
 
@@ -1680,6 +1687,8 @@ static int nvme_tcp_configure_admin_queu
 	if (error)
 		goto out_stop_queue;
 
+	blk_mq_unquiesce_queue(ctrl->admin_q);
+
 	error = nvme_init_identify(ctrl);
 	if (error)
 		goto out_stop_queue;
@@ -1691,6 +1700,9 @@ out_stop_queue:
 out_cleanup_queue:
 	if (new)
 		blk_cleanup_queue(ctrl->admin_q);
+out_cleanup_fabrics_q:
+	if (new)
+		blk_cleanup_queue(ctrl->fabrics_q);
 out_free_tagset:
 	if (new)
 		blk_mq_free_tag_set(ctrl->admin_tagset);
@@ -1709,7 +1721,8 @@ static void nvme_tcp_teardown_admin_queu
 			nvme_cancel_request, ctrl);
 		blk_mq_tagset_wait_completed_request(ctrl->admin_tagset);
 	}
-	blk_mq_unquiesce_queue(ctrl->admin_q);
+	if (remove)
+		blk_mq_unquiesce_queue(ctrl->admin_q);
 	nvme_tcp_destroy_admin_queue(ctrl, remove);
 }
 
@@ -1836,6 +1849,7 @@ static void nvme_tcp_error_recovery_work
 	/* unquiesce to fail fast pending requests */
 	nvme_start_queues(ctrl);
 	nvme_tcp_teardown_admin_queue(ctrl, false);
+	blk_mq_unquiesce_queue(ctrl->admin_q);
 
 	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_CONNECTING)) {
 		/* state change failure is ok if we're in DELETING state */
@@ -1849,6 +1863,7 @@ static void nvme_tcp_error_recovery_work
 static void nvme_tcp_teardown_ctrl(struct nvme_ctrl *ctrl, bool shutdown)
 {
 	nvme_tcp_teardown_io_queues(ctrl, shutdown);
+	blk_mq_quiesce_queue(ctrl->admin_q);
 	if (shutdown)
 		nvme_shutdown_ctrl(ctrl);
 	else
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -277,6 +277,7 @@ static void nvme_loop_destroy_admin_queu
 	clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
 	nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
 	blk_cleanup_queue(ctrl->ctrl.admin_q);
+	blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 	blk_mq_free_tag_set(&ctrl->admin_tag_set);
 }
 
@@ -381,10 +382,16 @@ static int nvme_loop_configure_admin_que
 		goto out_free_sq;
 	ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
 
+	ctrl->ctrl.fabrics_q = blk_mq_init_queue(&ctrl->admin_tag_set);
+	if (IS_ERR(ctrl->ctrl.fabrics_q)) {
+		error = PTR_ERR(ctrl->ctrl.fabrics_q);
+		goto out_free_tagset;
+	}
+
 	ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
 	if (IS_ERR(ctrl->ctrl.admin_q)) {
 		error = PTR_ERR(ctrl->ctrl.admin_q);
-		goto out_free_tagset;
+		goto out_cleanup_fabrics_q;
 	}
 
 	error = nvmf_connect_admin_queue(&ctrl->ctrl);
@@ -410,6 +417,8 @@ static int nvme_loop_configure_admin_que
 	ctrl->ctrl.max_hw_sectors =
 		(NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
 
+	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
+
 	error = nvme_init_identify(&ctrl->ctrl);
 	if (error)
 		goto out_cleanup_queue;
@@ -418,6 +427,8 @@ static int nvme_loop_configure_admin_que
 
 out_cleanup_queue:
 	blk_cleanup_queue(ctrl->ctrl.admin_q);
+out_cleanup_fabrics_q:
+	blk_cleanup_queue(ctrl->ctrl.fabrics_q);
 out_free_tagset:
 	blk_mq_free_tag_set(&ctrl->admin_tag_set);
 out_free_sq:
@@ -435,14 +446,13 @@ static void nvme_loop_shutdown_ctrl(stru
 		nvme_loop_destroy_io_queues(ctrl);
 	}
 
+	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 	if (ctrl->ctrl.state == NVME_CTRL_LIVE)
 		nvme_shutdown_ctrl(&ctrl->ctrl);
 
-	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 				nvme_cancel_request, &ctrl->ctrl);
 	blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set);
-	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 	nvme_loop_destroy_admin_queue(ctrl);
 }