[PATCH 0/5] nvme_fc: add ctlr reset support and abort fixes

[PATCH 0/5] nvme_fc: add ctlr reset support and abort fixes

[jsmart2021]

From: James Smart <jsmart2021@gmail.com>

This patch set primarily is to add support for controller reset.
It reorganizes the connect and teardown paths for cleaner support.
It also addresses some things that weren't there prior - aborts of link
services as well as aens.  Also fixes a few bugs.

James Smart (5):
  nvme_fc: Move LS's to rport
  nvme_fc: Add ls aborts on remote port teardown
  nvme_fc: fix command id check
  nvme_fc: add aen abort to teardown
  nvme_fc: add controller reset support

 drivers/nvme/host/fc.c | 1233 ++++++++++++++++++++++++++++++++----------------
 1 file changed, 834 insertions(+), 399 deletions(-)

-- 
2.9.3

[PATCH 1/5] nvme_fc: Move LS's to rport

[jsmart2021]

From: James Smart <jsmart2021@gmail.com>

Link LS's on the remoteport rather than the controller. LS's are
between nport's. Makes more sense, especially on async teardown where
the controller is torn down regardless of the LS (LS is more of a notifier
to the target of the teardown), to have them on the remoteport.

While revising ls send/done routines, issues were seen relative to
refcounting and cleanup, especially in async path. Reworked these code
paths.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
 drivers/nvme/host/fc.c | 119 +++++++++++++++++++++++++++----------------------
 1 file changed, 65 insertions(+), 54 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 5aefccf..2013713 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -64,13 +64,13 @@ struct nvme_fc_queue {
 struct nvmefc_ls_req_op {
 	struct nvmefc_ls_req	ls_req;
 
-	struct nvme_fc_ctrl	*ctrl;
+	struct nvme_fc_rport	*rport;
 	struct nvme_fc_queue	*queue;
 	struct request		*rq;
 
 	int			ls_error;
 	struct completion	ls_done;
-	struct list_head	lsreq_list;	/* ctrl->ls_req_list */
+	struct list_head	lsreq_list;	/* rport->ls_req_list */
 	bool			req_queued;
 };
 
@@ -120,6 +120,9 @@ struct nvme_fc_rport {
 
 	struct list_head		endp_list; /* for lport->endp_list */
 	struct list_head		ctrl_list;
+	struct list_head		ls_req_list;
+	struct device			*dev;	/* physical device for dma */
+	struct nvme_fc_lport		*lport;
 	spinlock_t			lock;
 	struct kref			ref;
 } __aligned(sizeof(u64));	/* alignment for other things alloc'd with */
@@ -144,7 +147,6 @@ struct nvme_fc_ctrl {
 	u64			cap;
 
 	struct list_head	ctrl_list;	/* rport->ctrl_list */
-	struct list_head	ls_req_list;
 
 	struct blk_mq_tag_set	admin_tag_set;
 	struct blk_mq_tag_set	tag_set;
@@ -419,9 +421,12 @@ nvme_fc_register_remoteport(struct nvme_fc_local_port *localport,
 
 	INIT_LIST_HEAD(&newrec->endp_list);
 	INIT_LIST_HEAD(&newrec->ctrl_list);
+	INIT_LIST_HEAD(&newrec->ls_req_list);
 	kref_init(&newrec->ref);
 	spin_lock_init(&newrec->lock);
 	newrec->remoteport.localport = &lport->localport;
+	newrec->dev = lport->dev;
+	newrec->lport = lport;
 	newrec->remoteport.private = &newrec[1];
 	newrec->remoteport.port_role = pinfo->port_role;
 	newrec->remoteport.node_name = pinfo->node_name;
@@ -444,7 +449,6 @@ nvme_fc_register_remoteport(struct nvme_fc_local_port *localport,
 out_reghost_failed:
 	*portptr = NULL;
 	return ret;
-
 }
 EXPORT_SYMBOL_GPL(nvme_fc_register_remoteport);
 
@@ -624,16 +628,16 @@ static int nvme_fc_ctrl_get(struct nvme_fc_ctrl *);
 
 
 static void
-__nvme_fc_finish_ls_req(struct nvme_fc_ctrl *ctrl,
-		struct nvmefc_ls_req_op *lsop)
+__nvme_fc_finish_ls_req(struct nvmefc_ls_req_op *lsop)
 {
+	struct nvme_fc_rport *rport = lsop->rport;
 	struct nvmefc_ls_req *lsreq = &lsop->ls_req;
 	unsigned long flags;
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	spin_lock_irqsave(&rport->lock, flags);
 
 	if (!lsop->req_queued) {
-		spin_unlock_irqrestore(&ctrl->lock, flags);
+		spin_unlock_irqrestore(&rport->lock, flags);
 		return;
 	}
 
@@ -641,56 +645,71 @@ __nvme_fc_finish_ls_req(struct nvme_fc_ctrl *ctrl,
 
 	lsop->req_queued = false;
 
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	spin_unlock_irqrestore(&rport->lock, flags);
 
-	fc_dma_unmap_single(ctrl->dev, lsreq->rqstdma,
+	fc_dma_unmap_single(rport->dev, lsreq->rqstdma,
 				  (lsreq->rqstlen + lsreq->rsplen),
 				  DMA_BIDIRECTIONAL);
 
-	nvme_fc_ctrl_put(ctrl);
+	nvme_fc_rport_put(rport);
 }
 
 static int
-__nvme_fc_send_ls_req(struct nvme_fc_ctrl *ctrl,
+__nvme_fc_send_ls_req(struct nvme_fc_rport *rport,
 		struct nvmefc_ls_req_op *lsop,
 		void (*done)(struct nvmefc_ls_req *req, int status))
 {
 	struct nvmefc_ls_req *lsreq = &lsop->ls_req;
 	unsigned long flags;
-	int ret;
+	int ret = 0;
 
-	if (!nvme_fc_ctrl_get(ctrl))
+	if (rport->remoteport.port_state != FC_OBJSTATE_ONLINE)
+		return -ECONNREFUSED;
+
+	if (!nvme_fc_rport_get(rport))
 		return -ESHUTDOWN;
 
 	lsreq->done = done;
-	lsop->ctrl = ctrl;
+	lsop->rport = rport;
 	lsop->req_queued = false;
 	INIT_LIST_HEAD(&lsop->lsreq_list);
 	init_completion(&lsop->ls_done);
 
-	lsreq->rqstdma = fc_dma_map_single(ctrl->dev, lsreq->rqstaddr,
+	lsreq->rqstdma = fc_dma_map_single(rport->dev, lsreq->rqstaddr,
 				  lsreq->rqstlen + lsreq->rsplen,
 				  DMA_BIDIRECTIONAL);
-	if (fc_dma_mapping_error(ctrl->dev, lsreq->rqstdma)) {
-		nvme_fc_ctrl_put(ctrl);
-		dev_err(ctrl->dev,
-			"els request command failed EFAULT.\n");
-		return -EFAULT;
+	if (fc_dma_mapping_error(rport->dev, lsreq->rqstdma)) {
+		ret = -EFAULT;
+		goto out_putrport;
 	}
 	lsreq->rspdma = lsreq->rqstdma + lsreq->rqstlen;
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	spin_lock_irqsave(&rport->lock, flags);
 
-	list_add_tail(&lsop->lsreq_list, &ctrl->ls_req_list);
+	list_add_tail(&lsop->lsreq_list, &rport->ls_req_list);
 
 	lsop->req_queued = true;
 
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	spin_unlock_irqrestore(&rport->lock, flags);
 
-	ret = ctrl->lport->ops->ls_req(&ctrl->lport->localport,
-					&ctrl->rport->remoteport, lsreq);
+	ret = rport->lport->ops->ls_req(&rport->lport->localport,
+					&rport->remoteport, lsreq);
 	if (ret)
-		lsop->ls_error = ret;
+		goto out_unlink;
+
+	return 0;
+
+out_unlink:
+	lsop->ls_error = ret;
+	spin_lock_irqsave(&rport->lock, flags);
+	lsop->req_queued = false;
+	list_del(&lsop->lsreq_list);
+	spin_unlock_irqrestore(&rport->lock, flags);
+	fc_dma_unmap_single(rport->dev, lsreq->rqstdma,
+				  (lsreq->rqstlen + lsreq->rsplen),
+				  DMA_BIDIRECTIONAL);
+out_putrport:
+	nvme_fc_rport_put(rport);
 
 	return ret;
 }
@@ -705,15 +724,15 @@ nvme_fc_send_ls_req_done(struct nvmefc_ls_req *lsreq, int status)
 }
 
 static int
-nvme_fc_send_ls_req(struct nvme_fc_ctrl *ctrl, struct nvmefc_ls_req_op *lsop)
+nvme_fc_send_ls_req(struct nvme_fc_rport *rport, struct nvmefc_ls_req_op *lsop)
 {
 	struct nvmefc_ls_req *lsreq = &lsop->ls_req;
 	struct fcnvme_ls_rjt *rjt = lsreq->rspaddr;
 	int ret;
 
-	ret = __nvme_fc_send_ls_req(ctrl, lsop, nvme_fc_send_ls_req_done);
+	ret = __nvme_fc_send_ls_req(rport, lsop, nvme_fc_send_ls_req_done);
 
-	if (!ret)
+	if (!ret) {
 		/*
 		 * No timeout/not interruptible as we need the struct
 		 * to exist until the lldd calls us back. Thus mandate
@@ -722,14 +741,14 @@ nvme_fc_send_ls_req(struct nvme_fc_ctrl *ctrl, struct nvmefc_ls_req_op *lsop)
 		 */
 		wait_for_completion(&lsop->ls_done);
 
-	__nvme_fc_finish_ls_req(ctrl, lsop);
+		__nvme_fc_finish_ls_req(lsop);
 
-	if (ret) {
-		dev_err(ctrl->dev,
-			"ls request command failed (%d).\n", ret);
-		return ret;
+		ret = lsop->ls_error;
 	}
 
+	if (ret)
+		return ret;
+
 	/* ACC or RJT payload ? */
 	if (rjt->w0.ls_cmd == FCNVME_LS_RJT)
 		return -ENXIO;
@@ -737,19 +756,14 @@ nvme_fc_send_ls_req(struct nvme_fc_ctrl *ctrl, struct nvmefc_ls_req_op *lsop)
 	return 0;
 }
 
-static void
-nvme_fc_send_ls_req_async(struct nvme_fc_ctrl *ctrl,
+static int
+nvme_fc_send_ls_req_async(struct nvme_fc_rport *rport,
 		struct nvmefc_ls_req_op *lsop,
 		void (*done)(struct nvmefc_ls_req *req, int status))
 {
-	int ret;
-
-	ret = __nvme_fc_send_ls_req(ctrl, lsop, done);
-
 	/* don't wait for completion */
 
-	if (ret)
-		done(&lsop->ls_req, ret);
+	return __nvme_fc_send_ls_req(rport, lsop, done);
 }
 
 /* Validation Error indexes into the string table below */
@@ -839,7 +853,7 @@ nvme_fc_connect_admin_queue(struct nvme_fc_ctrl *ctrl,
 	lsreq->rsplen = sizeof(*assoc_acc);
 	lsreq->timeout = NVME_FC_CONNECT_TIMEOUT_SEC;
 
-	ret = nvme_fc_send_ls_req(ctrl, lsop);
+	ret = nvme_fc_send_ls_req(ctrl->rport, lsop);
 	if (ret)
 		goto out_free_buffer;
 
@@ -947,7 +961,7 @@ nvme_fc_connect_queue(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 	lsreq->rsplen = sizeof(*conn_acc);
 	lsreq->timeout = NVME_FC_CONNECT_TIMEOUT_SEC;
 
-	ret = nvme_fc_send_ls_req(ctrl, lsop);
+	ret = nvme_fc_send_ls_req(ctrl->rport, lsop);
 	if (ret)
 		goto out_free_buffer;
 
@@ -998,14 +1012,8 @@ static void
 nvme_fc_disconnect_assoc_done(struct nvmefc_ls_req *lsreq, int status)
 {
 	struct nvmefc_ls_req_op *lsop = ls_req_to_lsop(lsreq);
-	struct nvme_fc_ctrl *ctrl = lsop->ctrl;
-
-	__nvme_fc_finish_ls_req(ctrl, lsop);
 
-	if (status)
-		dev_err(ctrl->dev,
-			"disconnect assoc ls request command failed (%d).\n",
-			status);
+	__nvme_fc_finish_ls_req(lsop);
 
 	/* fc-nvme iniator doesn't care about success or failure of cmd */
 
@@ -1036,6 +1044,7 @@ nvme_fc_xmt_disconnect_assoc(struct nvme_fc_ctrl *ctrl)
 	struct fcnvme_ls_disconnect_acc *discon_acc;
 	struct nvmefc_ls_req_op *lsop;
 	struct nvmefc_ls_req *lsreq;
+	int ret;
 
 	lsop = kzalloc((sizeof(*lsop) +
 			 ctrl->lport->ops->lsrqst_priv_sz +
@@ -1078,7 +1087,10 @@ nvme_fc_xmt_disconnect_assoc(struct nvme_fc_ctrl *ctrl)
 	lsreq->rsplen = sizeof(*discon_acc);
 	lsreq->timeout = NVME_FC_CONNECT_TIMEOUT_SEC;
 
-	nvme_fc_send_ls_req_async(ctrl, lsop, nvme_fc_disconnect_assoc_done);
+	ret = nvme_fc_send_ls_req_async(ctrl->rport, lsop,
+				nvme_fc_disconnect_assoc_done);
+	if (ret)
+		kfree(lsop);
 
 	/* only meaningful part to terminating the association */
 	ctrl->association_id = 0;
@@ -2316,7 +2328,6 @@ __nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
 	ctrl->ctrl.opts = opts;
 	INIT_LIST_HEAD(&ctrl->ctrl_list);
-	INIT_LIST_HEAD(&ctrl->ls_req_list);
 	ctrl->lport = lport;
 	ctrl->rport = rport;
 	ctrl->dev = lport->dev;
-- 
2.9.3

[PATCH 2/5] nvme_fc: Add ls aborts on remote port teardown

[jsmart2021]

From: James Smart <jsmart2021@gmail.com>

remoteport teardown never aborted the LS opertions. Add support.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
 drivers/nvme/host/fc.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 2013713..46594f1 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -61,12 +61,19 @@ struct nvme_fc_queue {
 	unsigned long		flags;
 } __aligned(sizeof(u64));	/* alignment for other things alloc'd with */
 
+enum nvme_fcop_flags {
+	FCOP_FLAGS_TERMIO	= (1 << 0),
+	FCOP_FLAGS_RELEASED	= (1 << 1),
+	FCOP_FLAGS_COMPLETE	= (1 << 2),
+};
+
 struct nvmefc_ls_req_op {
 	struct nvmefc_ls_req	ls_req;
 
 	struct nvme_fc_rport	*rport;
 	struct nvme_fc_queue	*queue;
 	struct request		*rq;
+	u32			flags;
 
 	int			ls_error;
 	struct completion	ls_done;
@@ -491,6 +498,30 @@ nvme_fc_rport_get(struct nvme_fc_rport *rport)
 	return kref_get_unless_zero(&rport->ref);
 }
 
+static int
+nvme_fc_abort_lsops(struct nvme_fc_rport *rport)
+{
+	struct nvmefc_ls_req_op *lsop;
+	unsigned long flags;
+
+restart:
+	spin_lock_irqsave(&rport->lock, flags);
+
+	list_for_each_entry(lsop, &rport->ls_req_list, lsreq_list) {
+		if (!(lsop->flags & FCOP_FLAGS_TERMIO)) {
+			lsop->flags |= FCOP_FLAGS_TERMIO;
+			spin_unlock_irqrestore(&rport->lock, flags);
+			rport->lport->ops->ls_abort(&rport->lport->localport,
+						&rport->remoteport,
+						&lsop->ls_req);
+			goto restart;
+		}
+	}
+	spin_unlock_irqrestore(&rport->lock, flags);
+
+	return 0;
+}
+
 /**
  * nvme_fc_unregister_remoteport - transport entry point called by an
  *                              LLDD to deregister/remove a previously
@@ -526,6 +557,8 @@ nvme_fc_unregister_remoteport(struct nvme_fc_remote_port *portptr)
 
 	spin_unlock_irqrestore(&rport->lock, flags);
 
+	nvme_fc_abort_lsops(rport);
+
 	nvme_fc_rport_put(rport);
 	return 0;
 }
-- 
2.9.3

[PATCH 3/5] nvme_fc: fix command id check

[jsmart2021]

From: James Smart <jsmart2021@gmail.com>

The code validates the command_id in the response to the original
sqe command. But prior code was using the rq->rqno as the sqe command
id. The core layer overwrites what the transport set there originally.

Use the actual sqe content.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
 drivers/nvme/host/fc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 46594f1..d5fc2da 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1192,6 +1192,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 	struct nvme_fc_ctrl *ctrl = op->ctrl;
 	struct nvme_fc_queue *queue = op->queue;
 	struct nvme_completion *cqe = &op->rsp_iu.cqe;
+	struct nvme_command *sqe = &op->cmd_iu.sqe;
 	u16 status = NVME_SC_SUCCESS;
 
 	/*
@@ -1273,7 +1274,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 			     be32_to_cpu(op->rsp_iu.xfrd_len) !=
 					freq->transferred_length ||
 			     op->rsp_iu.status_code ||
-			     op->rqno != le16_to_cpu(cqe->command_id))) {
+			     sqe->common.command_id != cqe->command_id)) {
 			status = NVME_SC_FC_TRANSPORT_ERROR;
 			goto done;
 		}
-- 
2.9.3

[PATCH 4/5] nvme_fc: add aen abort to teardown

[jsmart2021]

From: James Smart <jsmart2021@gmail.com>

Add abort support for aens. Commonized the op abort to apply to aen or
real ios (caused some reorg/routine movement). Abort path sets termination
flag in prep for next patch that will be watching i/o abort completion
before proceeding with controller teardown.

Now that we're aborting aens, the "exit" code that simply cleared out
their context no longer applies.

Also clarified how we detect an AEN vs a normal io - by a flag, not
by whether a rq exists or the a rqno is out of range.

Note: saw some interesting cases where if the queues are stopped and
we're waiting for the aborts, the core layer can call the complete_rq
callback for the io. So the io completion synchronizes link side completion
with possible blk layer completion under error.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
 drivers/nvme/host/fc.c | 192 +++++++++++++++++++++++++++++++++++--------------
 1 file changed, 140 insertions(+), 52 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index d5fc2da..9ea1f2a 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -65,6 +65,7 @@ enum nvme_fcop_flags {
 	FCOP_FLAGS_TERMIO	= (1 << 0),
 	FCOP_FLAGS_RELEASED	= (1 << 1),
 	FCOP_FLAGS_COMPLETE	= (1 << 2),
+	FCOP_FLAGS_AEN		= (1 << 3),
 };
 
 struct nvmefc_ls_req_op {
@@ -86,6 +87,7 @@ enum nvme_fcpop_state {
 	FCPOP_STATE_IDLE	= 1,
 	FCPOP_STATE_ACTIVE	= 2,
 	FCPOP_STATE_ABORTED	= 3,
+	FCPOP_STATE_COMPLETE	= 4,
 };
 
 struct nvme_fc_fcp_op {
@@ -104,6 +106,7 @@ struct nvme_fc_fcp_op {
 	struct request		*rq;
 
 	atomic_t		state;
+	u32			flags;
 	u32			rqno;
 	u32			nents;
 
@@ -1132,6 +1135,7 @@ nvme_fc_xmt_disconnect_assoc(struct nvme_fc_ctrl *ctrl)
 
 /* *********************** NVME Ctrl Routines **************************** */
 
+static void __nvme_fc_final_op_cleanup(struct request *rq);
 
 static int
 nvme_fc_reinit_request(void *data, struct request *rq)
@@ -1169,20 +1173,74 @@ nvme_fc_exit_request(void *data, struct request *rq,
 	return __nvme_fc_exit_request(data, op);
 }
 
+static int
+__nvme_fc_abort_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_fcp_op *op)
+{
+	int state;
+
+	state = atomic_xchg(&op->state, FCPOP_STATE_ABORTED);
+	if (state != FCPOP_STATE_ACTIVE) {
+		atomic_set(&op->state, state);
+		return -ECANCELED;
+	}
+
+	ctrl->lport->ops->fcp_abort(&ctrl->lport->localport,
+					&ctrl->rport->remoteport,
+					op->queue->lldd_handle,
+					&op->fcp_req);
+
+	return 0;
+}
+
 static void
-nvme_fc_exit_aen_ops(struct nvme_fc_ctrl *ctrl)
+nvme_fc_abort_aen_ops(struct nvme_fc_ctrl *ctrl)
 {
 	struct nvme_fc_fcp_op *aen_op = ctrl->aen_ops;
-	int i;
+	unsigned long flags;
+	int i, ret;
 
 	for (i = 0; i < NVME_FC_NR_AEN_COMMANDS; i++, aen_op++) {
-		if (atomic_read(&aen_op->state) == FCPOP_STATE_UNINIT)
+		if (atomic_read(&aen_op->state) != FCPOP_STATE_ACTIVE)
 			continue;
-		__nvme_fc_exit_request(ctrl, aen_op);
-		nvme_fc_ctrl_put(ctrl);
+
+		spin_lock_irqsave(&ctrl->lock, flags);
+		aen_op->flags |= FCOP_FLAGS_TERMIO;
+		spin_unlock_irqrestore(&ctrl->lock, flags);
+
+		ret = __nvme_fc_abort_op(ctrl, aen_op);
+		if (ret) {
+			/*
+			 * if __nvme_fc_abort_op failed the io wasn't
+			 * active. Thus this call path is running in
+			 * parallel to the io complete. Treat as non-error.
+			 */
+
+			/* back out the flags/counters */
+			spin_lock_irqsave(&ctrl->lock, flags);
+			aen_op->flags &= ~FCOP_FLAGS_TERMIO;
+			spin_unlock_irqrestore(&ctrl->lock, flags);
+			return;
+		}
 	}
 }
 
+static inline int
+__nvme_fc_fcpop_chk_teardowns(struct nvme_fc_ctrl *ctrl,
+		struct nvme_fc_fcp_op *op)
+{
+	unsigned long flags;
+	bool complete_rq = false;
+
+	spin_lock_irqsave(&ctrl->lock, flags);
+	if (op->flags & FCOP_FLAGS_RELEASED)
+		complete_rq = true;
+	else
+		op->flags |= FCOP_FLAGS_COMPLETE;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
+	return complete_rq;
+}
+
 void
 nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 {
@@ -1194,6 +1252,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 	struct nvme_completion *cqe = &op->rsp_iu.cqe;
 	struct nvme_command *sqe = &op->cmd_iu.sqe;
 	u16 status = NVME_SC_SUCCESS;
+	bool complete_rq;
 
 	/*
 	 * WARNING:
@@ -1288,14 +1347,26 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 	}
 
 done:
-	if (!queue->qnum && op->rqno >= AEN_CMDID_BASE) {
+	if (op->flags & FCOP_FLAGS_AEN) {
 		nvme_complete_async_event(&queue->ctrl->ctrl, status,
 					&op->nreq.result);
+		complete_rq = __nvme_fc_fcpop_chk_teardowns(ctrl, op);
+		atomic_set(&op->state, FCPOP_STATE_IDLE);
+		op->flags = FCOP_FLAGS_AEN;	/* clear other flags */
 		nvme_fc_ctrl_put(ctrl);
 		return;
 	}
 
-	blk_mq_complete_request(rq, status);
+	complete_rq = __nvme_fc_fcpop_chk_teardowns(ctrl, op);
+	if (!complete_rq) {
+		if (unlikely(op->flags & FCOP_FLAGS_TERMIO)) {
+			status = NVME_SC_ABORT_REQ;
+			if (blk_queue_dying(rq->q))
+				status |= NVME_SC_DNR;
+		}
+		blk_mq_complete_request(rq, status);
+	} else
+		__nvme_fc_final_op_cleanup(rq);
 }
 
 static int
@@ -1388,8 +1459,11 @@ nvme_fc_init_aen_ops(struct nvme_fc_ctrl *ctrl)
 		if (ret)
 			return ret;
 
+		aen_op->flags = FCOP_FLAGS_AEN;
+
 		memset(sqe, 0, sizeof(*sqe));
 		sqe->common.opcode = nvme_admin_async_event;
+		/* Note: core layer may overwrite the sqe.command_id value */
 		sqe->common.command_id = AEN_CMDID_BASE + i;
 	}
 	return 0;
@@ -1644,34 +1718,12 @@ nvme_fc_free_nvme_ctrl(struct nvme_ctrl *nctrl)
 			nvme_fc_free_io_queues(ctrl);
 		}
 
-		nvme_fc_exit_aen_ops(ctrl);
-
 		nvme_fc_destroy_admin_queue(ctrl);
 	}
 
 	nvme_fc_ctrl_put(ctrl);
 }
 
-
-static int
-__nvme_fc_abort_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_fcp_op *op)
-{
-	int state;
-
-	state = atomic_xchg(&op->state, FCPOP_STATE_ABORTED);
-	if (state != FCPOP_STATE_ACTIVE) {
-		atomic_set(&op->state, state);
-		return -ECANCELED; /* fail */
-	}
-
-	ctrl->lport->ops->fcp_abort(&ctrl->lport->localport,
-					&ctrl->rport->remoteport,
-					op->queue->lldd_handle,
-					&op->fcp_req);
-
-	return 0;
-}
-
 enum blk_eh_timer_return
 nvme_fc_timeout(struct request *rq, bool reserved)
 {
@@ -1830,10 +1882,7 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 	sqe->rw.dptr.sgl.length = cpu_to_le32(data_len);
 	sqe->rw.dptr.sgl.addr = 0;
 
-	/* odd that we set the command_id - should come from nvme-fabrics */
-	WARN_ON_ONCE(sqe->common.command_id != cpu_to_le16(op->rqno));
-
-	if (op->rq) {				/* skipped on aens */
+	if (!(op->flags & FCOP_FLAGS_AEN)) {
 		ret = nvme_fc_map_data(ctrl, op->rq, op);
 		if (ret < 0) {
 			dev_err(queue->ctrl->ctrl.device,
@@ -1850,7 +1899,7 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 
 	atomic_set(&op->state, FCPOP_STATE_ACTIVE);
 
-	if (op->rq)
+	if (!(op->flags & FCOP_FLAGS_AEN))
 		blk_mq_start_request(op->rq);
 
 	ret = ctrl->lport->ops->fcp_io(&ctrl->lport->localport,
@@ -1967,13 +2016,15 @@ nvme_fc_submit_async_event(struct nvme_ctrl *arg, int aer_idx)
 }
 
 static void
-nvme_fc_complete_rq(struct request *rq)
+__nvme_fc_final_op_cleanup(struct request *rq)
 {
 	struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(rq);
 	struct nvme_fc_ctrl *ctrl = op->ctrl;
-	int error = 0, state;
+	int error = 0;
 
-	state = atomic_xchg(&op->state, FCPOP_STATE_IDLE);
+	atomic_set(&op->state, FCPOP_STATE_IDLE);
+	op->flags &= ~(FCOP_FLAGS_TERMIO | FCOP_FLAGS_RELEASED |
+			FCOP_FLAGS_COMPLETE);
 
 	nvme_cleanup_cmd(rq);
 
@@ -1996,6 +2047,33 @@ nvme_fc_complete_rq(struct request *rq)
 	blk_mq_end_request(rq, error);
 }
 
+static void
+nvme_fc_complete_rq(struct request *rq)
+{
+	struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(rq);
+	struct nvme_fc_ctrl *ctrl = op->ctrl;
+	unsigned long flags;
+	bool completed = false;
+
+	/*
+	 * the core layer, on controller resets after calling
+	 * nvme_shutdown_ctrl(), calls complete_rq without our
+	 * calling blk_mq_complete_request(), thus there may still
+	 * be live i/o outstanding with the LLDD. Means transport has
+	 * to track complete calls vs fcpio_done calls to know what
+	 * path to take on completes and dones.
+	 */
+	spin_lock_irqsave(&ctrl->lock, flags);
+	if (op->flags & FCOP_FLAGS_COMPLETE)
+		completed = true;
+	else
+		op->flags |= FCOP_FLAGS_RELEASED;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
+	if (completed)
+		__nvme_fc_final_op_cleanup(rq);
+}
+
 static struct blk_mq_ops nvme_fc_mq_ops = {
 	.queue_rq	= nvme_fc_queue_rq,
 	.complete	= nvme_fc_complete_rq,
@@ -2119,25 +2197,32 @@ nvme_fc_terminate_exchange(struct request *req, void *data, bool reserved)
 	struct nvme_ctrl *nctrl = data;
 	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl);
 	struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(req);
-int status;
+	unsigned long flags;
+	int status;
 
 	if (!blk_mq_request_started(req))
 		return;
 
-	/* this performs an ABTS-LS on the FC exchange for the io */
+	spin_lock_irqsave(&ctrl->lock, flags);
+	op->flags |= FCOP_FLAGS_TERMIO;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
 	status = __nvme_fc_abort_op(ctrl, op);
-	/*
-	 * if __nvme_fc_abort_op failed: io wasn't active to abort
-	 * consider it done. Assume completion path already completing
-	 * in parallel
-	 */
-	if (status)
-		/* io wasn't active to abort consider it done */
-		/* assume completion path already completing in parallel */
+	if (status) {
+		/*
+		 * if __nvme_fc_abort_op failed the io wasn't
+		 * active. Thus this call path is running in
+		 * parallel to the io complete. Treat as non-error.
+		 */
+
+		/* back out the flags/counters */
+		spin_lock_irqsave(&ctrl->lock, flags);
+		op->flags &= ~FCOP_FLAGS_TERMIO;
+		spin_unlock_irqrestore(&ctrl->lock, flags);
 		return;
+	}
 }
 
-
 /*
  * This routine stops operation of the controller. Admin and IO queues
  * are stopped, outstanding ios on them terminated, and the nvme ctrl
@@ -2175,6 +2260,9 @@ nvme_fc_shutdown_ctrl(struct nvme_fc_ctrl *ctrl)
 	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
 	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 				nvme_fc_terminate_exchange, &ctrl->ctrl);
+
+	/* kill the aens as they are a separate path */
+	nvme_fc_abort_aen_ops(ctrl);
 }
 
 /*
@@ -2420,12 +2508,12 @@ __nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
 	ret = nvme_fc_init_aen_ops(ctrl);
 	if (ret)
-		goto out_exit_aen_ops;
+		goto out_stop_keep_alive;
 
 	if (ctrl->queue_count > 1) {
 		ret = nvme_fc_create_io_queues(ctrl);
 		if (ret)
-			goto out_exit_aen_ops;
+			goto out_stop_keep_alive;
 	}
 
 	spin_lock_irqsave(&ctrl->lock, flags);
@@ -2452,8 +2540,8 @@ __nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
 	return &ctrl->ctrl;
 
-out_exit_aen_ops:
-	nvme_fc_exit_aen_ops(ctrl);
+out_stop_keep_alive:
+	nvme_stop_keep_alive(&ctrl->ctrl);
 out_remove_admin_queue:
 	/* send a Disconnect(association) LS to fc-nvme target */
 	nvme_fc_xmt_disconnect_assoc(ctrl);
-- 
2.9.3

[PATCH 5/5] nvme_fc: add controller reset support

[jsmart2021]

From: James Smart <jsmart2021@gmail.com>

This patch actually does quite a few things.  When looking to add
controller reset support, the organization modeled after rdma was
very fragmented. rdma duplicates the reset and teardown paths and does
different things to the block layer on the two paths. The code to build
up the controller is also duplicated between the initial creation and
the reset/error recovery paths. So I decided to make this sane.

I reorganized the controller creation and teardown so that there is a
connect path and a disconnect path.  Initial creation obviously uses
the connect path.  Controller teardown will use the disconnect path,
followed last access code. Controller reset will use the disconnect
path to stop operation, and then the connect path to re-establish
the controller.

Along the way, several things were fixed
- aens were not properly set up. They are allocated differently from
  the per-request structure on the blk queues.
- aens were oddly torn down. the prior patch corrected to abort, but
  we still need to dma unmap and free relative elements.
- missed a few ref counting points: in aen completion and on i/o's
  that fail
- controller initial create failure paths were still confused vs teardown
  before converting to ref counting vs after we convert to refcounting.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
 drivers/nvme/host/fc.c | 1050 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 676 insertions(+), 374 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 9ea1f2a..3c02540 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -19,6 +19,7 @@
 #include <linux/parser.h>
 #include <uapi/scsi/fc/fc_fs.h>
 #include <uapi/scsi/fc/fc_els.h>
+#include <linux/delay.h>
 
 #include "nvme.h"
 #include "fabrics.h"
@@ -44,6 +45,8 @@ enum nvme_fc_queue_flags {
 
 #define NVMEFC_QUEUE_DELAY	3		/* ms units */
 
+#define NVME_FC_MAX_CONNECT_ATTEMPTS	1
+
 struct nvme_fc_queue {
 	struct nvme_fc_ctrl	*ctrl;
 	struct device		*dev;
@@ -137,19 +140,17 @@ struct nvme_fc_rport {
 	struct kref			ref;
 } __aligned(sizeof(u64));	/* alignment for other things alloc'd with */
 
-enum nvme_fcctrl_state {
-	FCCTRL_INIT		= 0,
-	FCCTRL_ACTIVE		= 1,
+enum nvme_fcctrl_flags {
+	FCCTRL_TERMIO		= (1 << 0),
 };
 
 struct nvme_fc_ctrl {
 	spinlock_t		lock;
 	struct nvme_fc_queue	*queues;
-	u32			queue_count;
-
 	struct device		*dev;
 	struct nvme_fc_lport	*lport;
 	struct nvme_fc_rport	*rport;
+	u32			queue_count;
 	u32			cnum;
 
 	u64			association_id;
@@ -162,8 +163,14 @@ struct nvme_fc_ctrl {
 	struct blk_mq_tag_set	tag_set;
 
 	struct work_struct	delete_work;
+	struct work_struct	reset_work;
+	struct delayed_work	connect_work;
+	int			reconnect_delay;
+	int			connect_attempts;
+
 	struct kref		ref;
-	int			state;
+	u32			flags;
+	u32			iocnt;
 
 	struct nvme_fc_fcp_op	aen_ops[NVME_FC_NR_AEN_COMMANDS];
 
@@ -1204,7 +1211,10 @@ nvme_fc_abort_aen_ops(struct nvme_fc_ctrl *ctrl)
 			continue;
 
 		spin_lock_irqsave(&ctrl->lock, flags);
-		aen_op->flags |= FCOP_FLAGS_TERMIO;
+		if (ctrl->flags & FCCTRL_TERMIO) {
+			ctrl->iocnt++;
+			aen_op->flags |= FCOP_FLAGS_TERMIO;
+		}
 		spin_unlock_irqrestore(&ctrl->lock, flags);
 
 		ret = __nvme_fc_abort_op(ctrl, aen_op);
@@ -1217,6 +1227,8 @@ nvme_fc_abort_aen_ops(struct nvme_fc_ctrl *ctrl)
 
 			/* back out the flags/counters */
 			spin_lock_irqsave(&ctrl->lock, flags);
+			if (ctrl->flags & FCCTRL_TERMIO)
+				ctrl->iocnt--;
 			aen_op->flags &= ~FCOP_FLAGS_TERMIO;
 			spin_unlock_irqrestore(&ctrl->lock, flags);
 			return;
@@ -1232,6 +1244,10 @@ __nvme_fc_fcpop_chk_teardowns(struct nvme_fc_ctrl *ctrl,
 	bool complete_rq = false;
 
 	spin_lock_irqsave(&ctrl->lock, flags);
+	if (unlikely(op->flags & FCOP_FLAGS_TERMIO)) {
+		if (ctrl->flags & FCCTRL_TERMIO)
+			ctrl->iocnt--;
+	}
 	if (op->flags & FCOP_FLAGS_RELEASED)
 		complete_rq = true;
 	else
@@ -1447,19 +1463,29 @@ nvme_fc_init_aen_ops(struct nvme_fc_ctrl *ctrl)
 	struct nvme_fc_fcp_op *aen_op;
 	struct nvme_fc_cmd_iu *cmdiu;
 	struct nvme_command *sqe;
+	void *private;
 	int i, ret;
 
 	aen_op = ctrl->aen_ops;
 	for (i = 0; i < NVME_FC_NR_AEN_COMMANDS; i++, aen_op++) {
+		private = kzalloc(ctrl->lport->ops->fcprqst_priv_sz,
+						GFP_KERNEL);
+		if (!private)
+			return -ENOMEM;
+
 		cmdiu = &aen_op->cmd_iu;
 		sqe = &cmdiu->sqe;
 		ret = __nvme_fc_init_request(ctrl, &ctrl->queues[0],
 				aen_op, (struct request *)NULL,
 				(AEN_CMDID_BASE + i));
-		if (ret)
+		if (ret) {
+			kfree(private);
 			return ret;
+		}
 
 		aen_op->flags = FCOP_FLAGS_AEN;
+		aen_op->fcp_req.first_sgl = NULL; /* no sg list */
+		aen_op->fcp_req.private = private;
 
 		memset(sqe, 0, sizeof(*sqe));
 		sqe->common.opcode = nvme_admin_async_event;
@@ -1469,6 +1495,23 @@ nvme_fc_init_aen_ops(struct nvme_fc_ctrl *ctrl)
 	return 0;
 }
 
+static void
+nvme_fc_term_aen_ops(struct nvme_fc_ctrl *ctrl)
+{
+	struct nvme_fc_fcp_op *aen_op;
+	int i;
+
+	aen_op = ctrl->aen_ops;
+	for (i = 0; i < NVME_FC_NR_AEN_COMMANDS; i++, aen_op++) {
+		if (!aen_op->fcp_req.private)
+			continue;
+
+		__nvme_fc_exit_request(ctrl, aen_op);
+
+		kfree(aen_op->fcp_req.private);
+		aen_op->fcp_req.private = NULL;
+	}
+}
 
 static inline void
 __nvme_fc_init_hctx(struct blk_mq_hw_ctx *hctx, struct nvme_fc_ctrl *ctrl,
@@ -1568,15 +1611,6 @@ __nvme_fc_delete_hw_queue(struct nvme_fc_ctrl *ctrl,
 }
 
 static void
-nvme_fc_destroy_admin_queue(struct nvme_fc_ctrl *ctrl)
-{
-	__nvme_fc_delete_hw_queue(ctrl, &ctrl->queues[0], 0);
-	blk_cleanup_queue(ctrl->ctrl.admin_q);
-	blk_mq_free_tag_set(&ctrl->admin_tag_set);
-	nvme_fc_free_queue(&ctrl->queues[0]);
-}
-
-static void
 nvme_fc_free_io_queues(struct nvme_fc_ctrl *ctrl)
 {
 	int i;
@@ -1663,17 +1697,24 @@ nvme_fc_ctrl_free(struct kref *ref)
 		container_of(ref, struct nvme_fc_ctrl, ref);
 	unsigned long flags;
 
-	if (ctrl->state != FCCTRL_INIT) {
-		/* remove from rport list */
-		spin_lock_irqsave(&ctrl->rport->lock, flags);
-		list_del(&ctrl->ctrl_list);
-		spin_unlock_irqrestore(&ctrl->rport->lock, flags);
+	if (ctrl->ctrl.tagset) {
+		blk_cleanup_queue(ctrl->ctrl.connect_q);
+		blk_mq_free_tag_set(&ctrl->tag_set);
 	}
 
+	/* remove from rport list */
+	spin_lock_irqsave(&ctrl->rport->lock, flags);
+	list_del(&ctrl->ctrl_list);
+	spin_unlock_irqrestore(&ctrl->rport->lock, flags);
+
+	blk_cleanup_queue(ctrl->ctrl.admin_q);
+	blk_mq_free_tag_set(&ctrl->admin_tag_set);
+
+	kfree(ctrl->queues);
+
 	put_device(ctrl->dev);
 	nvme_fc_rport_put(ctrl->rport);
 
-	kfree(ctrl->queues);
 	ida_simple_remove(&nvme_fc_ctrl_cnt, ctrl->cnum);
 	nvmf_free_options(ctrl->ctrl.opts);
 	kfree(ctrl);
@@ -1696,32 +1737,35 @@ nvme_fc_ctrl_get(struct nvme_fc_ctrl *ctrl)
  * controller. Called after last nvme_put_ctrl() call
  */
 static void
-nvme_fc_free_nvme_ctrl(struct nvme_ctrl *nctrl)
+nvme_fc_nvme_ctrl_freed(struct nvme_ctrl *nctrl)
 {
 	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl);
 
 	WARN_ON(nctrl != &ctrl->ctrl);
 
-	/*
-	 * Tear down the association, which will generate link
-	 * traffic to terminate connections
-	 */
-
-	if (ctrl->state != FCCTRL_INIT) {
-		/* send a Disconnect(association) LS to fc-nvme target */
-		nvme_fc_xmt_disconnect_assoc(ctrl);
+	nvme_fc_ctrl_put(ctrl);
+}
 
-		if (ctrl->ctrl.tagset) {
-			blk_cleanup_queue(ctrl->ctrl.connect_q);
-			blk_mq_free_tag_set(&ctrl->tag_set);
-			nvme_fc_delete_hw_io_queues(ctrl);
-			nvme_fc_free_io_queues(ctrl);
-		}
+static void
+nvme_fc_error_recovery(struct nvme_fc_ctrl *ctrl, char *errmsg)
+{
+	dev_warn(ctrl->ctrl.device,
+		"NVME-FC{%d}: transport association error detected: %s\n",
+		ctrl->cnum, errmsg);
+	dev_info(ctrl->ctrl.device,
+		"NVME-FC{%d}: resetting controller\n", ctrl->cnum);
 
-		nvme_fc_destroy_admin_queue(ctrl);
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RECONNECTING)) {
+		dev_err(ctrl->ctrl.device,
+			"NVME-FC{%d}: error_recovery: Couldn't change state "
+			"to RECONNECTING\n", ctrl->cnum);
+		return;
 	}
 
-	nvme_fc_ctrl_put(ctrl);
+	if (!queue_work(nvme_fc_wq, &ctrl->reset_work))
+		dev_err(ctrl->ctrl.device,
+			"NVME-FC{%d}: error_recovery: Failed to schedule "
+			"reset work\n", ctrl->cnum);
 }
 
 enum blk_eh_timer_return
@@ -1740,11 +1784,13 @@ nvme_fc_timeout(struct request *rq, bool reserved)
 		return BLK_EH_HANDLED;
 
 	/*
-	 * TODO: force a controller reset
-	 *   when that happens, queues will be torn down and outstanding
-	 *   ios will be terminated, and the above abort, on a single io
-	 *   will no longer be needed.
+	 * we can't individually ABTS an io without affecting the queue,
+	 * thus killing the queue, adn thus the association.
+	 * So resolve by performing a controller reset, which will stop
+	 * the host/io stack, terminate the association on the link,
+	 * and recreate an association on the link.
 	 */
+	nvme_fc_error_recovery(ctrl, "io timeout error");
 
 	return BLK_EH_HANDLED;
 }
@@ -1838,6 +1884,13 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 	u32 csn;
 	int ret;
 
+	/*
+	 * before attempting to send the io, check to see if we believe
+	 * the target device is present
+	 */
+	if (ctrl->rport->remoteport.port_state != FC_OBJSTATE_ONLINE)
+		return BLK_MQ_RQ_QUEUE_ERROR;
+
 	if (!nvme_fc_ctrl_get(ctrl))
 		return BLK_MQ_RQ_QUEUE_ERROR;
 
@@ -1885,8 +1938,6 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 	if (!(op->flags & FCOP_FLAGS_AEN)) {
 		ret = nvme_fc_map_data(ctrl, op->rq, op);
 		if (ret < 0) {
-			dev_err(queue->ctrl->ctrl.device,
-			     "Failed to map data (%d)\n", ret);
 			nvme_cleanup_cmd(op->rq);
 			nvme_fc_ctrl_put(ctrl);
 			return (ret == -ENOMEM || ret == -EAGAIN) ?
@@ -1907,9 +1958,6 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 					queue->lldd_handle, &op->fcp_req);
 
 	if (ret) {
-		dev_err(ctrl->dev,
-			"Send nvme command failed - lldd returned %d.\n", ret);
-
 		if (op->rq) {			/* normal request */
 			nvme_fc_unmap_data(ctrl, op->rq, op);
 			nvme_cleanup_cmd(op->rq);
@@ -1979,12 +2027,8 @@ nvme_fc_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
 	struct nvme_fc_fcp_op *op;
 
 	req = blk_mq_tag_to_rq(nvme_fc_tagset(queue), tag);
-	if (!req) {
-		dev_err(queue->ctrl->ctrl.device,
-			 "tag 0x%x on QNum %#x not found\n",
-			tag, queue->qnum);
+	if (!req)
 		return 0;
-	}
 
 	op = blk_mq_rq_to_pdu(req);
 
@@ -2001,11 +2045,21 @@ nvme_fc_submit_async_event(struct nvme_ctrl *arg, int aer_idx)
 {
 	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(arg);
 	struct nvme_fc_fcp_op *aen_op;
+	unsigned long flags;
+	bool terminating = false;
 	int ret;
 
 	if (aer_idx > NVME_FC_NR_AEN_COMMANDS)
 		return;
 
+	spin_lock_irqsave(&ctrl->lock, flags);
+	if (ctrl->flags & FCCTRL_TERMIO)
+		terminating = true;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
+	if (terminating)
+		return;
+
 	aen_op = &ctrl->aen_ops[aer_idx];
 
 	ret = nvme_fc_start_fcp_op(ctrl, aen_op->queue, aen_op, 0,
@@ -2033,6 +2087,7 @@ __nvme_fc_final_op_cleanup(struct request *rq)
 	if (unlikely(rq->errors)) {
 		if (nvme_req_needs_retry(rq, rq->errors)) {
 			nvme_requeue_req(rq);
+			nvme_fc_ctrl_put(ctrl);
 			return;
 		}
 
@@ -2074,110 +2129,6 @@ nvme_fc_complete_rq(struct request *rq)
 		__nvme_fc_final_op_cleanup(rq);
 }
 
-static struct blk_mq_ops nvme_fc_mq_ops = {
-	.queue_rq	= nvme_fc_queue_rq,
-	.complete	= nvme_fc_complete_rq,
-	.init_request	= nvme_fc_init_request,
-	.exit_request	= nvme_fc_exit_request,
-	.reinit_request	= nvme_fc_reinit_request,
-	.init_hctx	= nvme_fc_init_hctx,
-	.poll		= nvme_fc_poll,
-	.timeout	= nvme_fc_timeout,
-};
-
-static struct blk_mq_ops nvme_fc_admin_mq_ops = {
-	.queue_rq	= nvme_fc_queue_rq,
-	.complete	= nvme_fc_complete_rq,
-	.init_request	= nvme_fc_init_admin_request,
-	.exit_request	= nvme_fc_exit_request,
-	.reinit_request	= nvme_fc_reinit_request,
-	.init_hctx	= nvme_fc_init_admin_hctx,
-	.timeout	= nvme_fc_timeout,
-};
-
-static int
-nvme_fc_configure_admin_queue(struct nvme_fc_ctrl *ctrl)
-{
-	u32 segs;
-	int error;
-
-	nvme_fc_init_queue(ctrl, 0, NVME_FC_AQ_BLKMQ_DEPTH);
-
-	error = nvme_fc_connect_admin_queue(ctrl, &ctrl->queues[0],
-				NVME_FC_AQ_BLKMQ_DEPTH,
-				(NVME_FC_AQ_BLKMQ_DEPTH / 4));
-	if (error)
-		return error;
-
-	memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
-	ctrl->admin_tag_set.ops = &nvme_fc_admin_mq_ops;
-	ctrl->admin_tag_set.queue_depth = NVME_FC_AQ_BLKMQ_DEPTH;
-	ctrl->admin_tag_set.reserved_tags = 2; /* fabric connect + Keep-Alive */
-	ctrl->admin_tag_set.numa_node = NUMA_NO_NODE;
-	ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_fc_fcp_op) +
-					(SG_CHUNK_SIZE *
-						sizeof(struct scatterlist)) +
-					ctrl->lport->ops->fcprqst_priv_sz;
-	ctrl->admin_tag_set.driver_data = ctrl;
-	ctrl->admin_tag_set.nr_hw_queues = 1;
-	ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
-
-	error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
-	if (error)
-		goto out_free_queue;
-
-	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;
-	}
-
-	error = __nvme_fc_create_hw_queue(ctrl, &ctrl->queues[0], 0,
-				NVME_FC_AQ_BLKMQ_DEPTH);
-	if (error)
-		goto out_cleanup_queue;
-
-	error = nvmf_connect_admin_queue(&ctrl->ctrl);
-	if (error)
-		goto out_delete_hw_queue;
-
-	error = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->cap);
-	if (error) {
-		dev_err(ctrl->ctrl.device,
-			"prop_get NVME_REG_CAP failed\n");
-		goto out_delete_hw_queue;
-	}
-
-	ctrl->ctrl.sqsize =
-		min_t(int, NVME_CAP_MQES(ctrl->cap) + 1, ctrl->ctrl.sqsize);
-
-	error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->cap);
-	if (error)
-		goto out_delete_hw_queue;
-
-	segs = min_t(u32, NVME_FC_MAX_SEGMENTS,
-			ctrl->lport->ops->max_sgl_segments);
-	ctrl->ctrl.max_hw_sectors = (segs - 1) << (PAGE_SHIFT - 9);
-
-	error = nvme_init_identify(&ctrl->ctrl);
-	if (error)
-		goto out_delete_hw_queue;
-
-	nvme_start_keep_alive(&ctrl->ctrl);
-
-	return 0;
-
-out_delete_hw_queue:
-	__nvme_fc_delete_hw_queue(ctrl, &ctrl->queues[0], 0);
-out_cleanup_queue:
-	blk_cleanup_queue(ctrl->ctrl.admin_q);
-out_free_tagset:
-	blk_mq_free_tag_set(&ctrl->admin_tag_set);
-out_free_queue:
-	nvme_fc_free_queue(&ctrl->queues[0]);
-	return error;
-}
-
 /*
  * This routine is used by the transport when it needs to find active
  * io on a queue that is to be terminated. The transport uses
@@ -2204,7 +2155,10 @@ nvme_fc_terminate_exchange(struct request *req, void *data, bool reserved)
 		return;
 
 	spin_lock_irqsave(&ctrl->lock, flags);
-	op->flags |= FCOP_FLAGS_TERMIO;
+	if (ctrl->flags & FCCTRL_TERMIO) {
+		ctrl->iocnt++;
+		op->flags |= FCOP_FLAGS_TERMIO;
+	}
 	spin_unlock_irqrestore(&ctrl->lock, flags);
 
 	status = __nvme_fc_abort_op(ctrl, op);
@@ -2217,144 +2171,101 @@ nvme_fc_terminate_exchange(struct request *req, void *data, bool reserved)
 
 		/* back out the flags/counters */
 		spin_lock_irqsave(&ctrl->lock, flags);
+		if (ctrl->flags & FCCTRL_TERMIO)
+			ctrl->iocnt--;
 		op->flags &= ~FCOP_FLAGS_TERMIO;
 		spin_unlock_irqrestore(&ctrl->lock, flags);
 		return;
 	}
 }
 
-/*
- * This routine stops operation of the controller. Admin and IO queues
- * are stopped, outstanding ios on them terminated, and the nvme ctrl
- * is shutdown.
- */
-static void
-nvme_fc_shutdown_ctrl(struct nvme_fc_ctrl *ctrl)
-{
-	/*
-	 * If io queues are present, stop them and terminate all outstanding
-	 * ios on them. As FC allocates FC exchange for each io, the
-	 * transport must contact the LLDD to terminate the exchange,
-	 * thus releasing the FC exchange. We use blk_mq_tagset_busy_itr()
-	 * to tell us what io's are busy and invoke a transport routine
-	 * to kill them with the LLDD.  After terminating the exchange
-	 * the LLDD will call the transport's normal io done path, but it
-	 * will have an aborted status. The done path will return the
-	 * io requests back to the block layer as part of normal completions
-	 * (but with error status).
-	 */
-	if (ctrl->queue_count > 1) {
-		nvme_stop_queues(&ctrl->ctrl);
-		blk_mq_tagset_busy_iter(&ctrl->tag_set,
-				nvme_fc_terminate_exchange, &ctrl->ctrl);
-	}
-
-	if (ctrl->ctrl.state == NVME_CTRL_LIVE)
-		nvme_shutdown_ctrl(&ctrl->ctrl);
-
-	/*
-	 * now clean up the admin queue. Same thing as above.
-	 * use blk_mq_tagset_busy_itr() and the transport routine to
-	 * terminate the exchanges.
-	 */
-	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
-	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
-				nvme_fc_terminate_exchange, &ctrl->ctrl);
 
-	/* kill the aens as they are a separate path */
-	nvme_fc_abort_aen_ops(ctrl);
-}
+static struct blk_mq_ops nvme_fc_mq_ops = {
+	.queue_rq	= nvme_fc_queue_rq,
+	.complete	= nvme_fc_complete_rq,
+	.init_request	= nvme_fc_init_request,
+	.exit_request	= nvme_fc_exit_request,
+	.reinit_request	= nvme_fc_reinit_request,
+	.init_hctx	= nvme_fc_init_hctx,
+	.poll		= nvme_fc_poll,
+	.timeout	= nvme_fc_timeout,
+};
 
-/*
- * Called to teardown an association.
- * May be called with association fully in place or partially in place.
- */
-static void
-__nvme_fc_remove_ctrl(struct nvme_fc_ctrl *ctrl)
+static int
+nvme_fc_create_io_queues(struct nvme_fc_ctrl *ctrl)
 {
-	nvme_stop_keep_alive(&ctrl->ctrl);
+	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
+	int ret;
 
-	/* stop and terminate ios on admin and io queues */
-	nvme_fc_shutdown_ctrl(ctrl);
+	ret = nvme_set_queue_count(&ctrl->ctrl, &opts->nr_io_queues);
+	if (ret) {
+		dev_info(ctrl->ctrl.device,
+			"set_queue_count failed: %d\n", ret);
+		return ret;
+	}
 
-	/*
-	 * tear down the controller
-	 * This will result in the last reference on the nvme ctrl to
-	 * expire, calling the transport nvme_fc_free_nvme_ctrl() callback.
-	 * From there, the transport will tear down it's logical queues and
-	 * association.
-	 */
-	nvme_uninit_ctrl(&ctrl->ctrl);
+	ctrl->queue_count = opts->nr_io_queues + 1;
+	if (!opts->nr_io_queues)
+		return 0;
 
-	nvme_put_ctrl(&ctrl->ctrl);
-}
+	dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n",
+			opts->nr_io_queues);
 
-static void
-nvme_fc_del_ctrl_work(struct work_struct *work)
-{
-	struct nvme_fc_ctrl *ctrl =
-			container_of(work, struct nvme_fc_ctrl, delete_work);
+	nvme_fc_init_io_queues(ctrl);
 
-	__nvme_fc_remove_ctrl(ctrl);
-}
+	memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
+	ctrl->tag_set.ops = &nvme_fc_mq_ops;
+	ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
+	ctrl->tag_set.reserved_tags = 1; /* fabric connect */
+	ctrl->tag_set.numa_node = NUMA_NO_NODE;
+	ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+	ctrl->tag_set.cmd_size = sizeof(struct nvme_fc_fcp_op) +
+					(SG_CHUNK_SIZE *
+						sizeof(struct scatterlist)) +
+					ctrl->lport->ops->fcprqst_priv_sz;
+	ctrl->tag_set.driver_data = ctrl;
+	ctrl->tag_set.nr_hw_queues = ctrl->queue_count - 1;
+	ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
 
-static int
-__nvme_fc_del_ctrl(struct nvme_fc_ctrl *ctrl)
-{
-	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING))
-		return -EBUSY;
+	ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
+	if (ret)
+		return ret;
 
-	if (!queue_work(nvme_fc_wq, &ctrl->delete_work))
-		return -EBUSY;
+	ctrl->ctrl.tagset = &ctrl->tag_set;
 
-	return 0;
-}
+	ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
+	if (IS_ERR(ctrl->ctrl.connect_q)) {
+		ret = PTR_ERR(ctrl->ctrl.connect_q);
+		goto out_free_tag_set;
+	}
 
-/*
- * Request from nvme core layer to delete the controller
- */
-static int
-nvme_fc_del_nvme_ctrl(struct nvme_ctrl *nctrl)
-{
-	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl);
-	struct nvme_fc_rport *rport = ctrl->rport;
-	unsigned long flags;
-	int ret;
-
-	spin_lock_irqsave(&rport->lock, flags);
-	ret = __nvme_fc_del_ctrl(ctrl);
-	spin_unlock_irqrestore(&rport->lock, flags);
+	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.opts->queue_size);
 	if (ret)
-		return ret;
+		goto out_cleanup_blk_queue;
 
-	flush_work(&ctrl->delete_work);
+	ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.opts->queue_size);
+	if (ret)
+		goto out_delete_hw_queues;
 
 	return 0;
-}
 
-static int
-nvme_fc_reset_nvme_ctrl(struct nvme_ctrl *nctrl)
-{
-	return -EIO;
-}
+out_delete_hw_queues:
+	nvme_fc_delete_hw_io_queues(ctrl);
+out_cleanup_blk_queue:
+	nvme_stop_keep_alive(&ctrl->ctrl);
+	blk_cleanup_queue(ctrl->ctrl.connect_q);
+out_free_tag_set:
+	blk_mq_free_tag_set(&ctrl->tag_set);
+	nvme_fc_free_io_queues(ctrl);
 
-static const struct nvme_ctrl_ops nvme_fc_ctrl_ops = {
-	.name			= "fc",
-	.module			= THIS_MODULE,
-	.is_fabrics		= true,
-	.reg_read32		= nvmf_reg_read32,
-	.reg_read64		= nvmf_reg_read64,
-	.reg_write32		= nvmf_reg_write32,
-	.reset_ctrl		= nvme_fc_reset_nvme_ctrl,
-	.free_ctrl		= nvme_fc_free_nvme_ctrl,
-	.submit_async_event	= nvme_fc_submit_async_event,
-	.delete_ctrl		= nvme_fc_del_nvme_ctrl,
-	.get_subsysnqn		= nvmf_get_subsysnqn,
-	.get_address		= nvmf_get_address,
-};
+	/* force put free routine to ignore io queues */
+	ctrl->ctrl.tagset = NULL;
+
+	return ret;
+}
 
 static int
-nvme_fc_create_io_queues(struct nvme_fc_ctrl *ctrl)
+nvme_fc_reinit_io_queues(struct nvme_fc_ctrl *ctrl)
 {
 	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
 	int ret;
@@ -2366,44 +2277,22 @@ nvme_fc_create_io_queues(struct nvme_fc_ctrl *ctrl)
 		return ret;
 	}
 
-	ctrl->queue_count = opts->nr_io_queues + 1;
-	if (!opts->nr_io_queues)
+	/* check for io queues existing */
+	if (ctrl->queue_count == 1)
 		return 0;
 
-	dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n",
+	dev_info(ctrl->ctrl.device, "Recreating %d I/O queues.\n",
 			opts->nr_io_queues);
 
 	nvme_fc_init_io_queues(ctrl);
 
-	memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
-	ctrl->tag_set.ops = &nvme_fc_mq_ops;
-	ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
-	ctrl->tag_set.reserved_tags = 1; /* fabric connect */
-	ctrl->tag_set.numa_node = NUMA_NO_NODE;
-	ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
-	ctrl->tag_set.cmd_size = sizeof(struct nvme_fc_fcp_op) +
-					(SG_CHUNK_SIZE *
-						sizeof(struct scatterlist)) +
-					ctrl->lport->ops->fcprqst_priv_sz;
-	ctrl->tag_set.driver_data = ctrl;
-	ctrl->tag_set.nr_hw_queues = ctrl->queue_count - 1;
-	ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
-
-	ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
+	ret = blk_mq_reinit_tagset(&ctrl->tag_set);
 	if (ret)
-		return ret;
-
-	ctrl->ctrl.tagset = &ctrl->tag_set;
-
-	ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
-	if (IS_ERR(ctrl->ctrl.connect_q)) {
-		ret = PTR_ERR(ctrl->ctrl.connect_q);
-		goto out_free_tag_set;
-	}
+		goto out_free_io_queues;
 
 	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.opts->queue_size);
 	if (ret)
-		goto out_cleanup_blk_queue;
+		goto out_free_io_queues;
 
 	ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.opts->queue_size);
 	if (ret)
@@ -2413,28 +2302,440 @@ nvme_fc_create_io_queues(struct nvme_fc_ctrl *ctrl)
 
 out_delete_hw_queues:
 	nvme_fc_delete_hw_io_queues(ctrl);
-out_cleanup_blk_queue:
-	nvme_stop_keep_alive(&ctrl->ctrl);
-	blk_cleanup_queue(ctrl->ctrl.connect_q);
-out_free_tag_set:
-	blk_mq_free_tag_set(&ctrl->tag_set);
+out_free_io_queues:
 	nvme_fc_free_io_queues(ctrl);
+	return ret;
+}
 
-	/* force put free routine to ignore io queues */
-	ctrl->ctrl.tagset = NULL;
+/*
+ * This routine restarts the controller on the host side, and
+ * on the link side, recreates the controller association.
+ */
+static int
+nvme_fc_create_association(struct nvme_fc_ctrl *ctrl)
+{
+	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
+	u32 segs;
+	int ret;
+	bool changed;
+
+	ctrl->connect_attempts++;
+
+	/*
+	 * Create the admin queue
+	 */
+
+	nvme_fc_init_queue(ctrl, 0, NVME_FC_AQ_BLKMQ_DEPTH);
+
+	ret = __nvme_fc_create_hw_queue(ctrl, &ctrl->queues[0], 0,
+				NVME_FC_AQ_BLKMQ_DEPTH);
+	if (ret)
+		goto out_free_queue;
+
+	ret = nvme_fc_connect_admin_queue(ctrl, &ctrl->queues[0],
+				NVME_FC_AQ_BLKMQ_DEPTH,
+				(NVME_FC_AQ_BLKMQ_DEPTH / 4));
+	if (ret)
+		goto out_delete_hw_queue;
+
+	if (ctrl->ctrl.state != NVME_CTRL_NEW)
+		blk_mq_start_stopped_hw_queues(ctrl->ctrl.admin_q, true);
+
+	ret = nvmf_connect_admin_queue(&ctrl->ctrl);
+	if (ret)
+		goto out_disconnect_admin_queue;
+
+	/*
+	 * Check controller capabilities
+	 *
+	 * todo:- add code to check if ctrl attributes changed from
+	 * prior connection values
+	 */
+
+	ret = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->cap);
+	if (ret) {
+		dev_err(ctrl->ctrl.device,
+			"prop_get NVME_REG_CAP failed\n");
+		goto out_disconnect_admin_queue;
+	}
+
+	ctrl->ctrl.sqsize =
+		min_t(int, NVME_CAP_MQES(ctrl->cap) + 1, ctrl->ctrl.sqsize);
+
+	ret = nvme_enable_ctrl(&ctrl->ctrl, ctrl->cap);
+	if (ret)
+		goto out_disconnect_admin_queue;
+
+	segs = min_t(u32, NVME_FC_MAX_SEGMENTS,
+			ctrl->lport->ops->max_sgl_segments);
+	ctrl->ctrl.max_hw_sectors = (segs - 1) << (PAGE_SHIFT - 9);
+
+	ret = nvme_init_identify(&ctrl->ctrl);
+	if (ret)
+		goto out_disconnect_admin_queue;
+
+	/* sanity checks */
+
+	/* FC-NVME does not have other data in the capsule */
+	if (ctrl->ctrl.icdoff) {
+		dev_err(ctrl->ctrl.device, "icdoff %d is not supported!\n",
+				ctrl->ctrl.icdoff);
+		goto out_disconnect_admin_queue;
+	}
+
+	nvme_start_keep_alive(&ctrl->ctrl);
+
+	/* FC-NVME supports normal SGL Data Block Descriptors */
+
+	if (opts->queue_size > ctrl->ctrl.maxcmd) {
+		/* warn if maxcmd is lower than queue_size */
+		dev_warn(ctrl->ctrl.device,
+			"queue_size %zu > ctrl maxcmd %u, reducing "
+			"to queue_size\n",
+			opts->queue_size, ctrl->ctrl.maxcmd);
+		opts->queue_size = ctrl->ctrl.maxcmd;
+	}
+
+	ret = nvme_fc_init_aen_ops(ctrl);
+	if (ret)
+		goto out_term_aen_ops;
+
+	/*
+	 * Create the io queues
+	 */
+
+	if (ctrl->queue_count > 1) {
+		if (ctrl->ctrl.state == NVME_CTRL_NEW)
+			ret = nvme_fc_create_io_queues(ctrl);
+		else
+			ret = nvme_fc_reinit_io_queues(ctrl);
+		if (ret)
+			goto out_term_aen_ops;
+	}
+
+	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
+	WARN_ON_ONCE(!changed);
+
+	ctrl->connect_attempts = 0;
+
+	kref_get(&ctrl->ctrl.kref);
+
+	if (ctrl->queue_count > 1) {
+		nvme_start_queues(&ctrl->ctrl);
+		nvme_queue_scan(&ctrl->ctrl);
+		nvme_queue_async_events(&ctrl->ctrl);
+	}
+
+	return 0;	/* Success */
+
+out_term_aen_ops:
+	nvme_fc_term_aen_ops(ctrl);
+	nvme_stop_keep_alive(&ctrl->ctrl);
+out_disconnect_admin_queue:
+	/* send a Disconnect(association) LS to fc-nvme target */
+	nvme_fc_xmt_disconnect_assoc(ctrl);
+out_delete_hw_queue:
+	__nvme_fc_delete_hw_queue(ctrl, &ctrl->queues[0], 0);
+out_free_queue:
+	nvme_fc_free_queue(&ctrl->queues[0]);
 
 	return ret;
 }
 
+/*
+ * This routine stops operation of the controller on the host side.
+ * On the host os stack side: Admin and IO queues are stopped,
+ *   outstanding ios on them terminated via FC ABTS.
+ * On the link side: the association is terminated.
+ */
+static void
+nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
+{
+	unsigned long flags;
+
+	nvme_stop_keep_alive(&ctrl->ctrl);
+
+	spin_lock_irqsave(&ctrl->lock, flags);
+	ctrl->flags |= FCCTRL_TERMIO;
+	ctrl->iocnt = 0;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
+	/*
+	 * If io queues are present, stop them and terminate all outstanding
+	 * ios on them. As FC allocates FC exchange for each io, the
+	 * transport must contact the LLDD to terminate the exchange,
+	 * thus releasing the FC exchange. We use blk_mq_tagset_busy_itr()
+	 * to tell us what io's are busy and invoke a transport routine
+	 * to kill them with the LLDD.  After terminating the exchange
+	 * the LLDD will call the transport's normal io done path, but it
+	 * will have an aborted status. The done path will return the
+	 * io requests back to the block layer as part of normal completions
+	 * (but with error status).
+	 */
+	if (ctrl->queue_count > 1) {
+		nvme_stop_queues(&ctrl->ctrl);
+		blk_mq_tagset_busy_iter(&ctrl->tag_set,
+				nvme_fc_terminate_exchange, &ctrl->ctrl);
+	}
+
+	/*
+	 * Other transports, which don't have link-level contexts bound
+	 * to sqe's, would try to gracefully shutdown the controller by
+	 * writing the registers for shutdown and polling (call
+	 * nvme_shutdown_ctrl()). Given a bunch of i/o was potentially
+	 * just aborted and we will wait on those contexts, and given
+	 * there was no indication of how live the controlelr is on the
+	 * link, don't send more io to create more contexts for the
+	 * shutdown. Let the controller fail via keepalive failure if
+	 * its still present.
+	 */
+
+	/*
+	 * clean up the admin queue. Same thing as above.
+	 * use blk_mq_tagset_busy_itr() and the transport routine to
+	 * terminate the exchanges.
+	 */
+	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
+	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
+				nvme_fc_terminate_exchange, &ctrl->ctrl);
+
+	/* kill the aens as they are a separate path */
+	nvme_fc_abort_aen_ops(ctrl);
+
+	/* wait for all io that had to be aborted */
+	spin_lock_irqsave(&ctrl->lock, flags);
+	while (ctrl->iocnt) {
+		spin_unlock_irqrestore(&ctrl->lock, flags);
+		msleep(1000);
+		spin_lock_irqsave(&ctrl->lock, flags);
+	}
+	ctrl->flags &= ~FCCTRL_TERMIO;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
+	nvme_fc_term_aen_ops(ctrl);
+
+	/*
+	 * send a Disconnect(association) LS to fc-nvme target
+	 * Note: could have been sent at top of process, but
+	 * cleaner on link traffic if after the aborts complete.
+	 * Note: if association doesn't exist, association_id will be 0
+	 */
+	if (ctrl->association_id)
+		nvme_fc_xmt_disconnect_assoc(ctrl);
+
+	if (ctrl->ctrl.tagset) {
+		nvme_fc_delete_hw_io_queues(ctrl);
+		nvme_fc_free_io_queues(ctrl);
+	}
+
+	__nvme_fc_delete_hw_queue(ctrl, &ctrl->queues[0], 0);
+	nvme_fc_free_queue(&ctrl->queues[0]);
+}
+
+static void
+nvme_fc_delete_ctrl_work(struct work_struct *work)
+{
+	struct nvme_fc_ctrl *ctrl =
+		container_of(work, struct nvme_fc_ctrl, delete_work);
+
+	cancel_work_sync(&ctrl->reset_work);
+	cancel_delayed_work_sync(&ctrl->connect_work);
+
+	/*
+	 * kill the association on the link side.  this will block
+	 * waiting for io to terminate
+	 */
+	nvme_fc_delete_association(ctrl);
+
+	/*
+	 * tear down the controller
+	 * This will result in the last reference on the nvme ctrl to
+	 * expire, calling the transport nvme_fc_nvme_ctrl_freed() callback.
+	 * From there, the transport will tear down it's logical queues and
+	 * association.
+	 */
+	nvme_uninit_ctrl(&ctrl->ctrl);
+
+	nvme_put_ctrl(&ctrl->ctrl);
+}
+
+static int
+__nvme_fc_del_ctrl(struct nvme_fc_ctrl *ctrl)
+{
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING))
+		return -EBUSY;
+
+	if (!queue_work(nvme_fc_wq, &ctrl->delete_work))
+		return -EBUSY;
+
+	return 0;
+}
+
+/*
+ * Request from nvme core layer to delete the controller
+ */
+static int
+nvme_fc_del_nvme_ctrl(struct nvme_ctrl *nctrl)
+{
+	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl);
+	int ret;
+
+	if (!kref_get_unless_zero(&ctrl->ctrl.kref))
+		return -EBUSY;
+
+	ret = __nvme_fc_del_ctrl(ctrl);
+
+	if (!ret)
+		flush_workqueue(nvme_fc_wq);
+
+	nvme_put_ctrl(&ctrl->ctrl);
+
+	return ret;
+}
+
+static void
+nvme_fc_reset_ctrl_work(struct work_struct *work)
+{
+	struct nvme_fc_ctrl *ctrl =
+			container_of(work, struct nvme_fc_ctrl, reset_work);
+	int ret;
+
+	/* will block will waiting for io to terminate */
+	nvme_fc_delete_association(ctrl);
+
+	ret = nvme_fc_create_association(ctrl);
+	if (ret) {
+		dev_warn(ctrl->ctrl.device,
+			"NVME-FC{%d}: reset: Reconnect attempt failed (%d)\n",
+			ctrl->cnum, ret);
+		if (ctrl->connect_attempts >= NVME_FC_MAX_CONNECT_ATTEMPTS) {
+			dev_warn(ctrl->ctrl.device,
+				"NVME-FC{%d}: Max reconnect attempts (%d) "
+				"reached. Removing controller\n",
+				ctrl->cnum, ctrl->connect_attempts);
+
+			if (!nvme_change_ctrl_state(&ctrl->ctrl,
+				NVME_CTRL_DELETING)) {
+				dev_err(ctrl->ctrl.device,
+					"NVME-FC{%d}: failed to change state "
+					"to DELETING\n", ctrl->cnum);
+				return;
+			}
+
+			WARN_ON(!queue_work(nvme_fc_wq, &ctrl->delete_work));
+			return;
+		}
+
+		dev_warn(ctrl->ctrl.device,
+			"NVME-FC{%d}: Reconnect attempt in %d seconds.\n",
+			ctrl->cnum, ctrl->reconnect_delay);
+		queue_delayed_work(nvme_fc_wq, &ctrl->connect_work,
+				ctrl->reconnect_delay * HZ);
+	} else
+		dev_info(ctrl->ctrl.device,
+			"NVME-FC{%d}: controller reset complete\n", ctrl->cnum);
+}
+
+/*
+ * called by the nvme core layer, for sysfs interface that requests
+ * a reset of the nvme controller
+ */
+static int
+nvme_fc_reset_nvme_ctrl(struct nvme_ctrl *nctrl)
+{
+	struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl);
+
+	dev_warn(ctrl->ctrl.device,
+		"NVME-FC{%d}: admin requested controller reset\n", ctrl->cnum);
+
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING))
+		return -EBUSY;
+
+	if (!queue_work(nvme_fc_wq, &ctrl->reset_work))
+		return -EBUSY;
+
+	flush_work(&ctrl->reset_work);
+
+	return 0;
+}
+
+static const struct nvme_ctrl_ops nvme_fc_ctrl_ops = {
+	.name			= "fc",
+	.module			= THIS_MODULE,
+	.is_fabrics		= true,
+	.reg_read32		= nvmf_reg_read32,
+	.reg_read64		= nvmf_reg_read64,
+	.reg_write32		= nvmf_reg_write32,
+	.reset_ctrl		= nvme_fc_reset_nvme_ctrl,
+	.free_ctrl		= nvme_fc_nvme_ctrl_freed,
+	.submit_async_event	= nvme_fc_submit_async_event,
+	.delete_ctrl		= nvme_fc_del_nvme_ctrl,
+	.get_subsysnqn		= nvmf_get_subsysnqn,
+	.get_address		= nvmf_get_address,
+};
+
+static void
+nvme_fc_connect_ctrl_work(struct work_struct *work)
+{
+	int ret;
+
+	struct nvme_fc_ctrl *ctrl =
+			container_of(to_delayed_work(work),
+				struct nvme_fc_ctrl, connect_work);
+
+	ret = nvme_fc_create_association(ctrl);
+	if (ret) {
+		dev_warn(ctrl->ctrl.device,
+			"NVME-FC{%d}: Reconnect attempt failed (%d)\n",
+			ctrl->cnum, ret);
+		if (ctrl->connect_attempts >= NVME_FC_MAX_CONNECT_ATTEMPTS) {
+			dev_warn(ctrl->ctrl.device,
+				"NVME-FC{%d}: Max reconnect attempts (%d) "
+				"reached. Removing controller\n",
+				ctrl->cnum, ctrl->connect_attempts);
+
+			if (!nvme_change_ctrl_state(&ctrl->ctrl,
+				NVME_CTRL_DELETING)) {
+				dev_err(ctrl->ctrl.device,
+					"NVME-FC{%d}: failed to change state "
+					"to DELETING\n", ctrl->cnum);
+				return;
+			}
+
+			WARN_ON(!queue_work(nvme_fc_wq, &ctrl->delete_work));
+			return;
+		}
+
+		dev_warn(ctrl->ctrl.device,
+			"NVME-FC{%d}: Reconnect attempt in %d seconds.\n",
+			ctrl->cnum, ctrl->reconnect_delay);
+		queue_delayed_work(nvme_fc_wq, &ctrl->connect_work,
+				ctrl->reconnect_delay * HZ);
+	} else
+		dev_info(ctrl->ctrl.device,
+			"NVME-FC{%d}: controller reconnect complete\n",
+			ctrl->cnum);
+}
+
+
+static struct blk_mq_ops nvme_fc_admin_mq_ops = {
+	.queue_rq	= nvme_fc_queue_rq,
+	.complete	= nvme_fc_complete_rq,
+	.init_request	= nvme_fc_init_admin_request,
+	.exit_request	= nvme_fc_exit_request,
+	.reinit_request	= nvme_fc_reinit_request,
+	.init_hctx	= nvme_fc_init_admin_hctx,
+	.timeout	= nvme_fc_timeout,
+};
+
 
 static struct nvme_ctrl *
-__nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
+nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 	struct nvme_fc_lport *lport, struct nvme_fc_rport *rport)
 {
 	struct nvme_fc_ctrl *ctrl;
 	unsigned long flags;
 	int ret, idx;
-	bool changed;
 
 	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 	if (!ctrl) {
@@ -2453,17 +2754,15 @@ __nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 	ctrl->lport = lport;
 	ctrl->rport = rport;
 	ctrl->dev = lport->dev;
-	ctrl->state = FCCTRL_INIT;
 	ctrl->cnum = idx;
 
-	ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_fc_ctrl_ops, 0);
-	if (ret)
-		goto out_free_ida;
-
 	get_device(ctrl->dev);
 	kref_init(&ctrl->ref);
 
-	INIT_WORK(&ctrl->delete_work, nvme_fc_del_ctrl_work);
+	INIT_WORK(&ctrl->delete_work, nvme_fc_delete_ctrl_work);
+	INIT_WORK(&ctrl->reset_work, nvme_fc_reset_ctrl_work);
+	INIT_DELAYED_WORK(&ctrl->connect_work, nvme_fc_connect_ctrl_work);
+	ctrl->reconnect_delay = opts->reconnect_delay;
 	spin_lock_init(&ctrl->lock);
 
 	/* io queue count */
@@ -2480,87 +2779,86 @@ __nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 	ctrl->queues = kcalloc(ctrl->queue_count, sizeof(struct nvme_fc_queue),
 				GFP_KERNEL);
 	if (!ctrl->queues)
-		goto out_uninit_ctrl;
-
-	ret = nvme_fc_configure_admin_queue(ctrl);
-	if (ret)
-		goto out_uninit_ctrl;
-
-	/* sanity checks */
-
-	/* FC-NVME does not have other data in the capsule */
-	if (ctrl->ctrl.icdoff) {
-		dev_err(ctrl->ctrl.device, "icdoff %d is not supported!\n",
-				ctrl->ctrl.icdoff);
-		goto out_remove_admin_queue;
-	}
-
-	/* FC-NVME supports normal SGL Data Block Descriptors */
+		goto out_free_ida;
 
-	if (opts->queue_size > ctrl->ctrl.maxcmd) {
-		/* warn if maxcmd is lower than queue_size */
-		dev_warn(ctrl->ctrl.device,
-			"queue_size %zu > ctrl maxcmd %u, reducing "
-			"to queue_size\n",
-			opts->queue_size, ctrl->ctrl.maxcmd);
-		opts->queue_size = ctrl->ctrl.maxcmd;
-	}
+	memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
+	ctrl->admin_tag_set.ops = &nvme_fc_admin_mq_ops;
+	ctrl->admin_tag_set.queue_depth = NVME_FC_AQ_BLKMQ_DEPTH;
+	ctrl->admin_tag_set.reserved_tags = 2; /* fabric connect + Keep-Alive */
+	ctrl->admin_tag_set.numa_node = NUMA_NO_NODE;
+	ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_fc_fcp_op) +
+					(SG_CHUNK_SIZE *
+						sizeof(struct scatterlist)) +
+					ctrl->lport->ops->fcprqst_priv_sz;
+	ctrl->admin_tag_set.driver_data = ctrl;
+	ctrl->admin_tag_set.nr_hw_queues = 1;
+	ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
 
-	ret = nvme_fc_init_aen_ops(ctrl);
+	ret = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
 	if (ret)
-		goto out_stop_keep_alive;
+		goto out_free_queues;
 
-	if (ctrl->queue_count > 1) {
-		ret = nvme_fc_create_io_queues(ctrl);
-		if (ret)
-			goto out_stop_keep_alive;
+	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;
 	}
 
-	spin_lock_irqsave(&ctrl->lock, flags);
-	ctrl->state = FCCTRL_ACTIVE;
-	spin_unlock_irqrestore(&ctrl->lock, flags);
-
-	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
-	WARN_ON_ONCE(!changed);
+	/*
+	 * Would have been nice to init io queues tag set as well.
+	 * However, we require interaction from the controller
+	 * for max io queue count before we can do so.
+	 * Defer this to the connect path.
+	 */
 
-	dev_info(ctrl->ctrl.device,
-		"NVME-FC{%d}: new ctrl: NQN \"%s\"\n",
-		ctrl->cnum, ctrl->ctrl.opts->subsysnqn);
+	ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_fc_ctrl_ops, 0);
+	if (ret)
+		goto out_cleanup_admin_q;
 
-	kref_get(&ctrl->ctrl.kref);
+	/* at this point, teardown path changes to ref counting on nvme ctrl */
 
 	spin_lock_irqsave(&rport->lock, flags);
 	list_add_tail(&ctrl->ctrl_list, &rport->ctrl_list);
 	spin_unlock_irqrestore(&rport->lock, flags);
 
-	if (opts->nr_io_queues) {
-		nvme_queue_scan(&ctrl->ctrl);
-		nvme_queue_async_events(&ctrl->ctrl);
+	ret = nvme_fc_create_association(ctrl);
+	if (ret) {
+		/* initiate nvme ctrl ref counting teardown */
+		nvme_uninit_ctrl(&ctrl->ctrl);
+		nvme_put_ctrl(&ctrl->ctrl);
+
+		/* as we're past the point where we transition to the ref
+		 * counting teardown path, if we return a bad pointer here,
+		 * the calling routine, thinking it's prior to the
+		 * transition, will do an rport put. Since the teardown
+		 * path also does a rport put, we do an extra get here to
+		 * so proper order/teardown happens.
+		 */
+		nvme_fc_rport_get(rport);
+
+		if (ret > 0)
+			ret = -EIO;
+		return ERR_PTR(ret);
 	}
 
-	return &ctrl->ctrl;
+	dev_info(ctrl->ctrl.device,
+		"NVME-FC{%d}: new ctrl: NQN \"%s\"\n",
+		ctrl->cnum, ctrl->ctrl.opts->subsysnqn);
 
-out_stop_keep_alive:
-	nvme_stop_keep_alive(&ctrl->ctrl);
-out_remove_admin_queue:
-	/* send a Disconnect(association) LS to fc-nvme target */
-	nvme_fc_xmt_disconnect_assoc(ctrl);
-	nvme_stop_keep_alive(&ctrl->ctrl);
-	nvme_fc_destroy_admin_queue(ctrl);
-out_uninit_ctrl:
-	nvme_uninit_ctrl(&ctrl->ctrl);
-	nvme_put_ctrl(&ctrl->ctrl);
-	if (ret > 0)
-		ret = -EIO;
-	/* exit via here will follow ctlr ref point callbacks to free */
-	return ERR_PTR(ret);
+	return &ctrl->ctrl;
 
+out_cleanup_admin_q:
+	blk_cleanup_queue(ctrl->ctrl.admin_q);
+out_free_admin_tag_set:
+	blk_mq_free_tag_set(&ctrl->admin_tag_set);
+out_free_queues:
+	kfree(ctrl->queues);
 out_free_ida:
+	put_device(ctrl->dev);
 	ida_simple_remove(&nvme_fc_ctrl_cnt, ctrl->cnum);
 out_free_ctrl:
 	kfree(ctrl);
 out_fail:
-	nvme_fc_rport_put(rport);
 	/* exit via here doesn't follow ctlr ref points */
 	return ERR_PTR(ret);
 }
@@ -2632,6 +2930,7 @@ nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts)
 {
 	struct nvme_fc_lport *lport;
 	struct nvme_fc_rport *rport;
+	struct nvme_ctrl *ctrl;
 	struct nvmet_fc_traddr laddr = { 0L, 0L };
 	struct nvmet_fc_traddr raddr = { 0L, 0L };
 	unsigned long flags;
@@ -2663,7 +2962,10 @@ nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts)
 
 			spin_unlock_irqrestore(&nvme_fc_lock, flags);
 
-			return __nvme_fc_create_ctrl(dev, opts, lport, rport);
+			ctrl = nvme_fc_init_ctrl(dev, opts, lport, rport);
+			if (IS_ERR(ctrl))
+				nvme_fc_rport_put(rport);
+			return ctrl;
 		}
 	}
 	spin_unlock_irqrestore(&nvme_fc_lock, flags);
-- 
2.9.3