Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2121 insertions, 0 deletions

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
new file mode 100644
index 000000000..55f499952
--- /dev/null
+++ b/drivers/nvme/host/rdma.c
@@ -0,0 +1,2121 @@
+/*
+ * NVMe over Fabrics RDMA host code.
+ * Copyright (c) 2015-2016 HGST, a Western Digital Company.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <rdma/mr_pool.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/atomic.h>
+#include <linux/blk-mq.h>
+#include <linux/blk-mq-rdma.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/scatterlist.h>
+#include <linux/nvme.h>
+#include <asm/unaligned.h>
+
+#include <rdma/ib_verbs.h>
+#include <rdma/rdma_cm.h>
+#include <linux/nvme-rdma.h>
+
+#include "nvme.h"
+#include "fabrics.h"
+
+
+#define NVME_RDMA_CONNECT_TIMEOUT_MS	3000		/* 3 second */
+
+#define NVME_RDMA_MAX_SEGMENTS		256
+
+#define NVME_RDMA_MAX_INLINE_SEGMENTS	4
+
+struct nvme_rdma_device {
+	struct ib_device	*dev;
+	struct ib_pd		*pd;
+	struct kref		ref;
+	struct list_head	entry;
+	unsigned int		num_inline_segments;
+};
+
+struct nvme_rdma_qe {
+	struct ib_cqe		cqe;
+	void			*data;
+	u64			dma;
+};
+
+struct nvme_rdma_queue;
+struct nvme_rdma_request {
+	struct nvme_request	req;
+	struct ib_mr		*mr;
+	struct nvme_rdma_qe	sqe;
+	union nvme_result	result;
+	__le16			status;
+	refcount_t		ref;
+	struct ib_sge		sge[1 + NVME_RDMA_MAX_INLINE_SEGMENTS];
+	u32			num_sge;
+	int			nents;
+	struct ib_reg_wr	reg_wr;
+	struct ib_cqe		reg_cqe;
+	struct nvme_rdma_queue  *queue;
+	struct sg_table		sg_table;
+	struct scatterlist	first_sgl[];
+};
+
+enum nvme_rdma_queue_flags {
+	NVME_RDMA_Q_ALLOCATED		= 0,
+	NVME_RDMA_Q_LIVE		= 1,
+	NVME_RDMA_Q_TR_READY		= 2,
+};
+
+struct nvme_rdma_queue {
+	struct nvme_rdma_qe	*rsp_ring;
+	int			queue_size;
+	size_t			cmnd_capsule_len;
+	struct nvme_rdma_ctrl	*ctrl;
+	struct nvme_rdma_device	*device;
+	struct ib_cq		*ib_cq;
+	struct ib_qp		*qp;
+
+	unsigned long		flags;
+	struct rdma_cm_id	*cm_id;
+	int			cm_error;
+	struct completion	cm_done;
+};
+
+struct nvme_rdma_ctrl {
+	/* read only in the hot path */
+	struct nvme_rdma_queue	*queues;
+
+	/* other member variables */
+	struct blk_mq_tag_set	tag_set;
+	struct work_struct	err_work;
+
+	struct nvme_rdma_qe	async_event_sqe;
+
+	struct delayed_work	reconnect_work;
+
+	struct list_head	list;
+
+	struct blk_mq_tag_set	admin_tag_set;
+	struct nvme_rdma_device	*device;
+
+	u32			max_fr_pages;
+
+	struct sockaddr_storage addr;
+	struct sockaddr_storage src_addr;
+
+	struct nvme_ctrl	ctrl;
+	struct mutex		teardown_lock;
+	bool			use_inline_data;
+};
+
+static inline struct nvme_rdma_ctrl *to_rdma_ctrl(struct nvme_ctrl *ctrl)
+{
+	return container_of(ctrl, struct nvme_rdma_ctrl, ctrl);
+}
+
+static LIST_HEAD(device_list);
+static DEFINE_MUTEX(device_list_mutex);
+
+static LIST_HEAD(nvme_rdma_ctrl_list);
+static DEFINE_MUTEX(nvme_rdma_ctrl_mutex);
+
+/*
+ * Disabling this option makes small I/O goes faster, but is fundamentally
+ * unsafe.  With it turned off we will have to register a global rkey that
+ * allows read and write access to all physical memory.
+ */
+static bool register_always = true;
+module_param(register_always, bool, 0444);
+MODULE_PARM_DESC(register_always,
+	 "Use memory registration even for contiguous memory regions");
+
+static int nvme_rdma_cm_handler(struct rdma_cm_id *cm_id,
+		struct rdma_cm_event *event);
+static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc);
+
+static const struct blk_mq_ops nvme_rdma_mq_ops;
+static const struct blk_mq_ops nvme_rdma_admin_mq_ops;
+
+/* XXX: really should move to a generic header sooner or later.. */
+static inline void put_unaligned_le24(u32 val, u8 *p)
+{
+	*p++ = val;
+	*p++ = val >> 8;
+	*p++ = val >> 16;
+}
+
+static inline int nvme_rdma_queue_idx(struct nvme_rdma_queue *queue)
+{
+	return queue - queue->ctrl->queues;
+}
+
+static inline size_t nvme_rdma_inline_data_size(struct nvme_rdma_queue *queue)
+{
+	return queue->cmnd_capsule_len - sizeof(struct nvme_command);
+}
+
+static void nvme_rdma_free_qe(struct ib_device *ibdev, struct nvme_rdma_qe *qe,
+		size_t capsule_size, enum dma_data_direction dir)
+{
+	ib_dma_unmap_single(ibdev, qe->dma, capsule_size, dir);
+	kfree(qe->data);
+}
+
+static int nvme_rdma_alloc_qe(struct ib_device *ibdev, struct nvme_rdma_qe *qe,
+		size_t capsule_size, enum dma_data_direction dir)
+{
+	qe->data = kzalloc(capsule_size, GFP_KERNEL);
+	if (!qe->data)
+		return -ENOMEM;
+
+	qe->dma = ib_dma_map_single(ibdev, qe->data, capsule_size, dir);
+	if (ib_dma_mapping_error(ibdev, qe->dma)) {
+		kfree(qe->data);
+		qe->data = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void nvme_rdma_free_ring(struct ib_device *ibdev,
+		struct nvme_rdma_qe *ring, size_t ib_queue_size,
+		size_t capsule_size, enum dma_data_direction dir)
+{
+	int i;
+
+	for (i = 0; i < ib_queue_size; i++)
+		nvme_rdma_free_qe(ibdev, &ring[i], capsule_size, dir);
+	kfree(ring);
+}
+
+static struct nvme_rdma_qe *nvme_rdma_alloc_ring(struct ib_device *ibdev,
+		size_t ib_queue_size, size_t capsule_size,
+		enum dma_data_direction dir)
+{
+	struct nvme_rdma_qe *ring;
+	int i;
+
+	ring = kcalloc(ib_queue_size, sizeof(struct nvme_rdma_qe), GFP_KERNEL);
+	if (!ring)
+		return NULL;
+
+	for (i = 0; i < ib_queue_size; i++) {
+		if (nvme_rdma_alloc_qe(ibdev, &ring[i], capsule_size, dir))
+			goto out_free_ring;
+	}
+
+	return ring;
+
+out_free_ring:
+	nvme_rdma_free_ring(ibdev, ring, i, capsule_size, dir);
+	return NULL;
+}
+
+static void nvme_rdma_qp_event(struct ib_event *event, void *context)
+{
+	pr_debug("QP event %s (%d)\n",
+		 ib_event_msg(event->event), event->event);
+
+}
+
+static int nvme_rdma_wait_for_cm(struct nvme_rdma_queue *queue)
+{
+	wait_for_completion_interruptible_timeout(&queue->cm_done,
+			msecs_to_jiffies(NVME_RDMA_CONNECT_TIMEOUT_MS) + 1);
+	return queue->cm_error;
+}
+
+static int nvme_rdma_create_qp(struct nvme_rdma_queue *queue, const int factor)
+{
+	struct nvme_rdma_device *dev = queue->device;
+	struct ib_qp_init_attr init_attr;
+	int ret;
+
+	memset(&init_attr, 0, sizeof(init_attr));
+	init_attr.event_handler = nvme_rdma_qp_event;
+	/* +1 for drain */
+	init_attr.cap.max_send_wr = factor * queue->queue_size + 1;
+	/* +1 for drain */
+	init_attr.cap.max_recv_wr = queue->queue_size + 1;
+	init_attr.cap.max_recv_sge = 1;
+	init_attr.cap.max_send_sge = 1 + dev->num_inline_segments;
+	init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
+	init_attr.qp_type = IB_QPT_RC;
+	init_attr.send_cq = queue->ib_cq;
+	init_attr.recv_cq = queue->ib_cq;
+
+	ret = rdma_create_qp(queue->cm_id, dev->pd, &init_attr);
+
+	queue->qp = queue->cm_id->qp;
+	return ret;
+}
+
+static void nvme_rdma_exit_request(struct blk_mq_tag_set *set,
+		struct request *rq, unsigned int hctx_idx)
+{
+	struct nvme_rdma_ctrl *ctrl = set->driver_data;
+	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
+	int queue_idx = (set == &ctrl->tag_set) ? hctx_idx + 1 : 0;
+	struct nvme_rdma_queue *queue = &ctrl->queues[queue_idx];
+	struct nvme_rdma_device *dev = queue->device;
+
+	nvme_rdma_free_qe(dev->dev, &req->sqe, sizeof(struct nvme_command),
+			DMA_TO_DEVICE);
+}
+
+static int nvme_rdma_init_request(struct blk_mq_tag_set *set,
+		struct request *rq, unsigned int hctx_idx,
+		unsigned int numa_node)
+{
+	struct nvme_rdma_ctrl *ctrl = set->driver_data;
+	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
+	int queue_idx = (set == &ctrl->tag_set) ? hctx_idx + 1 : 0;
+	struct nvme_rdma_queue *queue = &ctrl->queues[queue_idx];
+	struct nvme_rdma_device *dev = queue->device;
+	struct ib_device *ibdev = dev->dev;
+	int ret;
+
+	nvme_req(rq)->ctrl = &ctrl->ctrl;
+	ret = nvme_rdma_alloc_qe(ibdev, &req->sqe, sizeof(struct nvme_command),
+			DMA_TO_DEVICE);
+	if (ret)
+		return ret;
+
+	req->queue = queue;
+
+	return 0;
+}
+
+static int nvme_rdma_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+		unsigned int hctx_idx)
+{
+	struct nvme_rdma_ctrl *ctrl = data;
+	struct nvme_rdma_queue *queue = &ctrl->queues[hctx_idx + 1];
+
+	BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
+
+	hctx->driver_data = queue;
+	return 0;
+}
+
+static int nvme_rdma_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+		unsigned int hctx_idx)
+{
+	struct nvme_rdma_ctrl *ctrl = data;
+	struct nvme_rdma_queue *queue = &ctrl->queues[0];
+
+	BUG_ON(hctx_idx != 0);
+
+	hctx->driver_data = queue;
+	return 0;
+}
+
+static void nvme_rdma_free_dev(struct kref *ref)
+{
+	struct nvme_rdma_device *ndev =
+		container_of(ref, struct nvme_rdma_device, ref);
+
+	mutex_lock(&device_list_mutex);
+	list_del(&ndev->entry);
+	mutex_unlock(&device_list_mutex);
+
+	ib_dealloc_pd(ndev->pd);
+	kfree(ndev);
+}
+
+static void nvme_rdma_dev_put(struct nvme_rdma_device *dev)
+{
+	kref_put(&dev->ref, nvme_rdma_free_dev);
+}
+
+static int nvme_rdma_dev_get(struct nvme_rdma_device *dev)
+{
+	return kref_get_unless_zero(&dev->ref);
+}
+
+static struct nvme_rdma_device *
+nvme_rdma_find_get_device(struct rdma_cm_id *cm_id)
+{
+	struct nvme_rdma_device *ndev;
+
+	mutex_lock(&device_list_mutex);
+	list_for_each_entry(ndev, &device_list, entry) {
+		if (ndev->dev->node_guid == cm_id->device->node_guid &&
+		    nvme_rdma_dev_get(ndev))
+			goto out_unlock;
+	}
+
+	ndev = kzalloc(sizeof(*ndev), GFP_KERNEL);
+	if (!ndev)
+		goto out_err;
+
+	ndev->dev = cm_id->device;
+	kref_init(&ndev->ref);
+
+	ndev->pd = ib_alloc_pd(ndev->dev,
+		register_always ? 0 : IB_PD_UNSAFE_GLOBAL_RKEY);
+	if (IS_ERR(ndev->pd))
+		goto out_free_dev;
+
+	if (!(ndev->dev->attrs.device_cap_flags &
+	      IB_DEVICE_MEM_MGT_EXTENSIONS)) {
+		dev_err(&ndev->dev->dev,
+			"Memory registrations not supported.\n");
+		goto out_free_pd;
+	}
+
+	ndev->num_inline_segments = min(NVME_RDMA_MAX_INLINE_SEGMENTS,
+					ndev->dev->attrs.max_send_sge - 1);
+	list_add(&ndev->entry, &device_list);
+out_unlock:
+	mutex_unlock(&device_list_mutex);
+	return ndev;
+
+out_free_pd:
+	ib_dealloc_pd(ndev->pd);
+out_free_dev:
+	kfree(ndev);
+out_err:
+	mutex_unlock(&device_list_mutex);
+	return NULL;
+}
+
+static void nvme_rdma_destroy_queue_ib(struct nvme_rdma_queue *queue)
+{
+	struct nvme_rdma_device *dev;
+	struct ib_device *ibdev;
+
+	if (!test_and_clear_bit(NVME_RDMA_Q_TR_READY, &queue->flags))
+		return;
+
+	dev = queue->device;
+	ibdev = dev->dev;
+
+	ib_mr_pool_destroy(queue->qp, &queue->qp->rdma_mrs);
+
+	/*
+	 * The cm_id object might have been destroyed during RDMA connection
+	 * establishment error flow to avoid getting other cma events, thus
+	 * the destruction of the QP shouldn't use rdma_cm API.
+	 */
+	ib_destroy_qp(queue->qp);
+	ib_free_cq(queue->ib_cq);
+
+	nvme_rdma_free_ring(ibdev, queue->rsp_ring, queue->queue_size,
+			sizeof(struct nvme_completion), DMA_FROM_DEVICE);
+
+	nvme_rdma_dev_put(dev);
+}
+
+static int nvme_rdma_get_max_fr_pages(struct ib_device *ibdev)
+{
+	return min_t(u32, NVME_RDMA_MAX_SEGMENTS,
+		     ibdev->attrs.max_fast_reg_page_list_len);
+}
+
+static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
+{
+	struct ib_device *ibdev;
+	const int send_wr_factor = 3;			/* MR, SEND, INV */
+	const int cq_factor = send_wr_factor + 1;	/* + RECV */
+	int comp_vector, idx = nvme_rdma_queue_idx(queue);
+	int ret;
+
+	queue->device = nvme_rdma_find_get_device(queue->cm_id);
+	if (!queue->device) {
+		dev_err(queue->cm_id->device->dev.parent,
+			"no client data found!\n");
+		return -ECONNREFUSED;
+	}
+	ibdev = queue->device->dev;
+
+	/*
+	 * Spread I/O queues completion vectors according their queue index.
+	 * Admin queues can always go on completion vector 0.
+	 */
+	comp_vector = (idx == 0 ? idx : idx - 1) % ibdev->num_comp_vectors;
+
+	/* +1 for ib_stop_cq */
+	queue->ib_cq = ib_alloc_cq(ibdev, queue,
+				cq_factor * queue->queue_size + 1,
+				comp_vector, IB_POLL_SOFTIRQ);
+	if (IS_ERR(queue->ib_cq)) {
+		ret = PTR_ERR(queue->ib_cq);
+		goto out_put_dev;
+	}
+
+	ret = nvme_rdma_create_qp(queue, send_wr_factor);
+	if (ret)
+		goto out_destroy_ib_cq;
+
+	queue->rsp_ring = nvme_rdma_alloc_ring(ibdev, queue->queue_size,
+			sizeof(struct nvme_completion), DMA_FROM_DEVICE);
+	if (!queue->rsp_ring) {
+		ret = -ENOMEM;
+		goto out_destroy_qp;
+	}
+
+	ret = ib_mr_pool_init(queue->qp, &queue->qp->rdma_mrs,
+			      queue->queue_size,
+			      IB_MR_TYPE_MEM_REG,
+			      nvme_rdma_get_max_fr_pages(ibdev));
+	if (ret) {
+		dev_err(queue->ctrl->ctrl.device,
+			"failed to initialize MR pool sized %d for QID %d\n",
+			queue->queue_size, idx);
+		goto out_destroy_ring;
+	}
+
+	set_bit(NVME_RDMA_Q_TR_READY, &queue->flags);
+
+	return 0;
+
+out_destroy_ring:
+	nvme_rdma_free_ring(ibdev, queue->rsp_ring, queue->queue_size,
+			    sizeof(struct nvme_completion), DMA_FROM_DEVICE);
+out_destroy_qp:
+	rdma_destroy_qp(queue->cm_id);
+out_destroy_ib_cq:
+	ib_free_cq(queue->ib_cq);
+out_put_dev:
+	nvme_rdma_dev_put(queue->device);
+	return ret;
+}
+
+static int nvme_rdma_alloc_queue(struct nvme_rdma_ctrl *ctrl,
+		int idx, size_t queue_size)
+{
+	struct nvme_rdma_queue *queue;
+	struct sockaddr *src_addr = NULL;
+	int ret;
+
+	queue = &ctrl->queues[idx];
+	queue->ctrl = ctrl;
+	init_completion(&queue->cm_done);
+
+	if (idx > 0)
+		queue->cmnd_capsule_len = ctrl->ctrl.ioccsz * 16;
+	else
+		queue->cmnd_capsule_len = sizeof(struct nvme_command);
+
+	queue->queue_size = queue_size;
+
+	queue->cm_id = rdma_create_id(&init_net, nvme_rdma_cm_handler, queue,
+			RDMA_PS_TCP, IB_QPT_RC);
+	if (IS_ERR(queue->cm_id)) {
+		dev_info(ctrl->ctrl.device,
+			"failed to create CM ID: %ld\n", PTR_ERR(queue->cm_id));
+		return PTR_ERR(queue->cm_id);
+	}
+
+	if (ctrl->ctrl.opts->mask & NVMF_OPT_HOST_TRADDR)
+		src_addr = (struct sockaddr *)&ctrl->src_addr;
+
+	queue->cm_error = -ETIMEDOUT;
+	ret = rdma_resolve_addr(queue->cm_id, src_addr,
+			(struct sockaddr *)&ctrl->addr,
+			NVME_RDMA_CONNECT_TIMEOUT_MS);
+	if (ret) {
+		dev_info(ctrl->ctrl.device,
+			"rdma_resolve_addr failed (%d).\n", ret);
+		goto out_destroy_cm_id;
+	}
+
+	ret = nvme_rdma_wait_for_cm(queue);
+	if (ret) {
+		dev_info(ctrl->ctrl.device,
+			"rdma connection establishment failed (%d)\n", ret);
+		goto out_destroy_cm_id;
+	}
+
+	set_bit(NVME_RDMA_Q_ALLOCATED, &queue->flags);
+
+	return 0;
+
+out_destroy_cm_id:
+	rdma_destroy_id(queue->cm_id);
+	nvme_rdma_destroy_queue_ib(queue);
+	return ret;
+}
+
+static void nvme_rdma_stop_queue(struct nvme_rdma_queue *queue)
+{
+	if (!test_and_clear_bit(NVME_RDMA_Q_LIVE, &queue->flags))
+		return;
+
+	rdma_disconnect(queue->cm_id);
+	ib_drain_qp(queue->qp);
+}
+
+static void nvme_rdma_free_queue(struct nvme_rdma_queue *queue)
+{
+	if (!test_and_clear_bit(NVME_RDMA_Q_ALLOCATED, &queue->flags))
+		return;
+
+	nvme_rdma_destroy_queue_ib(queue);
+	rdma_destroy_id(queue->cm_id);
+}
+
+static void nvme_rdma_free_io_queues(struct nvme_rdma_ctrl *ctrl)
+{
+	int i;
+
+	for (i = 1; i < ctrl->ctrl.queue_count; i++)
+		nvme_rdma_free_queue(&ctrl->queues[i]);
+}
+
+static void nvme_rdma_stop_io_queues(struct nvme_rdma_ctrl *ctrl)
+{
+	int i;
+
+	for (i = 1; i < ctrl->ctrl.queue_count; i++)
+		nvme_rdma_stop_queue(&ctrl->queues[i]);
+}
+
+static int nvme_rdma_start_queue(struct nvme_rdma_ctrl *ctrl, int idx)
+{
+	int ret;
+
+	if (idx)
+		ret = nvmf_connect_io_queue(&ctrl->ctrl, idx);
+	else
+		ret = nvmf_connect_admin_queue(&ctrl->ctrl);
+
+	if (!ret)
+		set_bit(NVME_RDMA_Q_LIVE, &ctrl->queues[idx].flags);
+	else
+		dev_info(ctrl->ctrl.device,
+			"failed to connect queue: %d ret=%d\n", idx, ret);
+	return ret;
+}
+
+static int nvme_rdma_start_io_queues(struct nvme_rdma_ctrl *ctrl)
+{
+	int i, ret = 0;
+
+	for (i = 1; i < ctrl->ctrl.queue_count; i++) {
+		ret = nvme_rdma_start_queue(ctrl, i);
+		if (ret)
+			goto out_stop_queues;
+	}
+
+	return 0;
+
+out_stop_queues:
+	for (i--; i >= 1; i--)
+		nvme_rdma_stop_queue(&ctrl->queues[i]);
+	return ret;
+}
+
+static int nvme_rdma_alloc_io_queues(struct nvme_rdma_ctrl *ctrl)
+{
+	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
+	struct ib_device *ibdev = ctrl->device->dev;
+	unsigned int nr_io_queues;
+	int i, ret;
+
+	nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
+
+	/*
+	 * we map queues according to the device irq vectors for
+	 * optimal locality so we don't need more queues than
+	 * completion vectors.
+	 */
+	nr_io_queues = min_t(unsigned int, nr_io_queues,
+				ibdev->num_comp_vectors);
+
+	ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
+	if (ret)
+		return ret;
+
+	if (nr_io_queues == 0) {
+		dev_err(ctrl->ctrl.device,
+			"unable to set any I/O queues\n");
+		return -ENOMEM;
+	}
+
+	ctrl->ctrl.queue_count = nr_io_queues + 1;
+	dev_info(ctrl->ctrl.device,
+		"creating %d I/O queues.\n", nr_io_queues);
+
+	for (i = 1; i < ctrl->ctrl.queue_count; i++) {
+		ret = nvme_rdma_alloc_queue(ctrl, i,
+				ctrl->ctrl.sqsize + 1);
+		if (ret)
+			goto out_free_queues;
+	}
+
+	return 0;
+
+out_free_queues:
+	for (i--; i >= 1; i--)
+		nvme_rdma_free_queue(&ctrl->queues[i]);
+
+	return ret;
+}
+
+static void nvme_rdma_free_tagset(struct nvme_ctrl *nctrl,
+		struct blk_mq_tag_set *set)
+{
+	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
+
+	blk_mq_free_tag_set(set);
+	nvme_rdma_dev_put(ctrl->device);
+}
+
+static struct blk_mq_tag_set *nvme_rdma_alloc_tagset(struct nvme_ctrl *nctrl,
+		bool admin)
+{
+	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
+	struct blk_mq_tag_set *set;
+	int ret;
+
+	if (admin) {
+		set = &ctrl->admin_tag_set;
+		memset(set, 0, sizeof(*set));
+		set->ops = &nvme_rdma_admin_mq_ops;
+		set->queue_depth = NVME_AQ_MQ_TAG_DEPTH;
+		set->reserved_tags = 2; /* connect + keep-alive */
+		set->numa_node = NUMA_NO_NODE;
+		set->cmd_size = sizeof(struct nvme_rdma_request) +
+			SG_CHUNK_SIZE * sizeof(struct scatterlist);
+		set->driver_data = ctrl;
+		set->nr_hw_queues = 1;
+		set->timeout = ADMIN_TIMEOUT;
+		set->flags = BLK_MQ_F_NO_SCHED;
+	} else {
+		set = &ctrl->tag_set;
+		memset(set, 0, sizeof(*set));
+		set->ops = &nvme_rdma_mq_ops;
+		set->queue_depth = nctrl->sqsize + 1;
+		set->reserved_tags = 1; /* fabric connect */
+		set->numa_node = NUMA_NO_NODE;
+		set->flags = BLK_MQ_F_SHOULD_MERGE;
+		set->cmd_size = sizeof(struct nvme_rdma_request) +
+			SG_CHUNK_SIZE * sizeof(struct scatterlist);
+		set->driver_data = ctrl;
+		set->nr_hw_queues = nctrl->queue_count - 1;
+		set->timeout = NVME_IO_TIMEOUT;
+	}
+
+	ret = blk_mq_alloc_tag_set(set);
+	if (ret)
+		goto out;
+
+	/*
+	 * We need a reference on the device as long as the tag_set is alive,
+	 * as the MRs in the request structures need a valid ib_device.
+	 */
+	ret = nvme_rdma_dev_get(ctrl->device);
+	if (!ret) {
+		ret = -EINVAL;
+		goto out_free_tagset;
+	}
+
+	return set;
+
+out_free_tagset:
+	blk_mq_free_tag_set(set);
+out:
+	return ERR_PTR(ret);
+}
+
+static void nvme_rdma_destroy_admin_queue(struct nvme_rdma_ctrl *ctrl,
+		bool remove)
+{
+	if (remove) {
+		blk_cleanup_queue(ctrl->ctrl.admin_q);
+		nvme_rdma_free_tagset(&ctrl->ctrl, ctrl->ctrl.admin_tagset);
+	}
+	if (ctrl->async_event_sqe.data) {
+		cancel_work_sync(&ctrl->ctrl.async_event_work);
+		nvme_rdma_free_qe(ctrl->device->dev, &ctrl->async_event_sqe,
+				sizeof(struct nvme_command), DMA_TO_DEVICE);
+		ctrl->async_event_sqe.data = NULL;
+	}
+	nvme_rdma_free_queue(&ctrl->queues[0]);
+}
+
+static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl,
+		bool new)
+{
+	int error;
+
+	error = nvme_rdma_alloc_queue(ctrl, 0, NVME_AQ_DEPTH);
+	if (error)
+		return error;
+
+	ctrl->device = ctrl->queues[0].device;
+
+	ctrl->max_fr_pages = nvme_rdma_get_max_fr_pages(ctrl->device->dev);
+
+	error = nvme_rdma_alloc_qe(ctrl->device->dev, &ctrl->async_event_sqe,
+			sizeof(struct nvme_command), DMA_TO_DEVICE);
+	if (error)
+		goto out_free_queue;
+
+	if (new) {
+		ctrl->ctrl.admin_tagset = nvme_rdma_alloc_tagset(&ctrl->ctrl, true);
+		if (IS_ERR(ctrl->ctrl.admin_tagset)) {
+			error = PTR_ERR(ctrl->ctrl.admin_tagset);
+			goto out_free_async_qe;
+		}
+
+		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_rdma_start_queue(ctrl, 0);
+	if (error)
+		goto out_cleanup_queue;
+
+	error = ctrl->ctrl.ops->reg_read64(&ctrl->ctrl, NVME_REG_CAP,
+			&ctrl->ctrl.cap);
+	if (error) {
+		dev_err(ctrl->ctrl.device,
+			"prop_get NVME_REG_CAP failed\n");
+		goto out_stop_queue;
+	}
+
+	ctrl->ctrl.sqsize =
+		min_t(int, NVME_CAP_MQES(ctrl->ctrl.cap), ctrl->ctrl.sqsize);
+
+	error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->ctrl.cap);
+	if (error)
+		goto out_stop_queue;
+
+	ctrl->ctrl.max_hw_sectors =
+		(ctrl->max_fr_pages - 1) << (ilog2(SZ_4K) - 9);
+
+	error = nvme_init_identify(&ctrl->ctrl);
+	if (error)
+		goto out_stop_queue;
+
+	return 0;
+
+out_stop_queue:
+	nvme_rdma_stop_queue(&ctrl->queues[0]);
+out_cleanup_queue:
+	if (new)
+		blk_cleanup_queue(ctrl->ctrl.admin_q);
+out_free_tagset:
+	if (new)
+		nvme_rdma_free_tagset(&ctrl->ctrl, ctrl->ctrl.admin_tagset);
+out_free_async_qe:
+	if (ctrl->async_event_sqe.data) {
+		nvme_rdma_free_qe(ctrl->device->dev, &ctrl->async_event_sqe,
+			sizeof(struct nvme_command), DMA_TO_DEVICE);
+		ctrl->async_event_sqe.data = NULL;
+	}
+out_free_queue:
+	nvme_rdma_free_queue(&ctrl->queues[0]);
+	return error;
+}
+
+static void nvme_rdma_destroy_io_queues(struct nvme_rdma_ctrl *ctrl,
+		bool remove)
+{
+	if (remove) {
+		blk_cleanup_queue(ctrl->ctrl.connect_q);
+		nvme_rdma_free_tagset(&ctrl->ctrl, ctrl->ctrl.tagset);
+	}
+	nvme_rdma_free_io_queues(ctrl);
+}
+
+static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
+{
+	int ret;
+
+	ret = nvme_rdma_alloc_io_queues(ctrl);
+	if (ret)
+		return ret;
+
+	if (new) {
+		ctrl->ctrl.tagset = nvme_rdma_alloc_tagset(&ctrl->ctrl, false);
+		if (IS_ERR(ctrl->ctrl.tagset)) {
+			ret = PTR_ERR(ctrl->ctrl.tagset);
+			goto out_free_io_queues;
+		}
+
+		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;
+		}
+	} else {
+		blk_mq_update_nr_hw_queues(&ctrl->tag_set,
+			ctrl->ctrl.queue_count - 1);
+	}
+
+	ret = nvme_rdma_start_io_queues(ctrl);
+	if (ret)
+		goto out_cleanup_connect_q;
+
+	return 0;
+
+out_cleanup_connect_q:
+	if (new)
+		blk_cleanup_queue(ctrl->ctrl.connect_q);
+out_free_tag_set:
+	if (new)
+		nvme_rdma_free_tagset(&ctrl->ctrl, ctrl->ctrl.tagset);
+out_free_io_queues:
+	nvme_rdma_free_io_queues(ctrl);
+	return ret;
+}
+
+static void nvme_rdma_teardown_admin_queue(struct nvme_rdma_ctrl *ctrl,
+		bool remove)
+{
+	mutex_lock(&ctrl->teardown_lock);
+	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
+	nvme_rdma_stop_queue(&ctrl->queues[0]);
+	if (ctrl->ctrl.admin_tagset)
+		blk_mq_tagset_busy_iter(ctrl->ctrl.admin_tagset,
+			nvme_cancel_request, &ctrl->ctrl);
+	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
+	nvme_rdma_destroy_admin_queue(ctrl, remove);
+	mutex_unlock(&ctrl->teardown_lock);
+}
+
+static void nvme_rdma_teardown_io_queues(struct nvme_rdma_ctrl *ctrl,
+		bool remove)
+{
+	mutex_lock(&ctrl->teardown_lock);
+	if (ctrl->ctrl.queue_count > 1) {
+		nvme_stop_queues(&ctrl->ctrl);
+		nvme_rdma_stop_io_queues(ctrl);
+		if (ctrl->ctrl.tagset)
+			blk_mq_tagset_busy_iter(ctrl->ctrl.tagset,
+				nvme_cancel_request, &ctrl->ctrl);
+		if (remove)
+			nvme_start_queues(&ctrl->ctrl);
+		nvme_rdma_destroy_io_queues(ctrl, remove);
+	}
+	mutex_unlock(&ctrl->teardown_lock);
+}
+
+static void nvme_rdma_stop_ctrl(struct nvme_ctrl *nctrl)
+{
+	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
+
+	cancel_work_sync(&ctrl->err_work);
+	cancel_delayed_work_sync(&ctrl->reconnect_work);
+}
+
+static void nvme_rdma_free_ctrl(struct nvme_ctrl *nctrl)
+{
+	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
+
+	if (list_empty(&ctrl->list))
+		goto free_ctrl;
+
+	mutex_lock(&nvme_rdma_ctrl_mutex);
+	list_del(&ctrl->list);
+	mutex_unlock(&nvme_rdma_ctrl_mutex);
+
+	nvmf_free_options(nctrl->opts);
+free_ctrl:
+	kfree(ctrl->queues);
+	kfree(ctrl);
+}
+
+static void nvme_rdma_reconnect_or_remove(struct nvme_rdma_ctrl *ctrl)
+{
+	/* If we are resetting/deleting then do nothing */
+	if (ctrl->ctrl.state != NVME_CTRL_CONNECTING) {
+		WARN_ON_ONCE(ctrl->ctrl.state == NVME_CTRL_NEW ||
+			ctrl->ctrl.state == NVME_CTRL_LIVE);
+		return;
+	}
+
+	if (nvmf_should_reconnect(&ctrl->ctrl)) {
+		dev_info(ctrl->ctrl.device, "Reconnecting in %d seconds...\n",
+			ctrl->ctrl.opts->reconnect_delay);
+		queue_delayed_work(nvme_wq, &ctrl->reconnect_work,
+				ctrl->ctrl.opts->reconnect_delay * HZ);
+	} else {
+		nvme_delete_ctrl(&ctrl->ctrl);
+	}
+}
+
+static int nvme_rdma_setup_ctrl(struct nvme_rdma_ctrl *ctrl, bool new)
+{
+	int ret = -EINVAL;
+	bool changed;
+
+	ret = nvme_rdma_configure_admin_queue(ctrl, new);
+	if (ret)
+		return ret;
+
+	if (ctrl->ctrl.icdoff) {
+		ret = -EOPNOTSUPP;
+		dev_err(ctrl->ctrl.device, "icdoff is not supported!\n");
+		goto destroy_admin;
+	}
+
+	if (!(ctrl->ctrl.sgls & (1 << 2))) {
+		ret = -EOPNOTSUPP;
+		dev_err(ctrl->ctrl.device,
+			"Mandatory keyed sgls are not supported!\n");
+		goto destroy_admin;
+	}
+
+	if (ctrl->ctrl.opts->queue_size > ctrl->ctrl.sqsize + 1) {
+		dev_warn(ctrl->ctrl.device,
+			"queue_size %zu > ctrl sqsize %u, clamping down\n",
+			ctrl->ctrl.opts->queue_size, ctrl->ctrl.sqsize + 1);
+	}
+
+	if (ctrl->ctrl.sqsize + 1 > ctrl->ctrl.maxcmd) {
+		dev_warn(ctrl->ctrl.device,
+			"sqsize %u > ctrl maxcmd %u, clamping down\n",
+			ctrl->ctrl.sqsize + 1, ctrl->ctrl.maxcmd);
+		ctrl->ctrl.sqsize = ctrl->ctrl.maxcmd - 1;
+	}
+
+	if (ctrl->ctrl.sgls & (1 << 20))
+		ctrl->use_inline_data = true;
+
+	if (ctrl->ctrl.queue_count > 1) {
+		ret = nvme_rdma_configure_io_queues(ctrl, new);
+		if (ret)
+			goto destroy_admin;
+	}
+
+	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
+	if (!changed) {
+		/* state change failure is ok if we're in DELETING state */
+		WARN_ON_ONCE(ctrl->ctrl.state != NVME_CTRL_DELETING);
+		ret = -EINVAL;
+		goto destroy_io;
+	}
+
+	nvme_start_ctrl(&ctrl->ctrl);
+	return 0;
+
+destroy_io:
+	if (ctrl->ctrl.queue_count > 1)
+		nvme_rdma_destroy_io_queues(ctrl, new);
+destroy_admin:
+	nvme_rdma_stop_queue(&ctrl->queues[0]);
+	nvme_rdma_destroy_admin_queue(ctrl, new);
+	return ret;
+}
+
+static void nvme_rdma_reconnect_ctrl_work(struct work_struct *work)
+{
+	struct nvme_rdma_ctrl *ctrl = container_of(to_delayed_work(work),
+			struct nvme_rdma_ctrl, reconnect_work);
+
+	++ctrl->ctrl.nr_reconnects;
+
+	if (nvme_rdma_setup_ctrl(ctrl, false))
+		goto requeue;
+
+	dev_info(ctrl->ctrl.device, "Successfully reconnected (%d attempts)\n",
+			ctrl->ctrl.nr_reconnects);
+
+	ctrl->ctrl.nr_reconnects = 0;
+
+	return;
+
+requeue:
+	dev_info(ctrl->ctrl.device, "Failed reconnect attempt %d\n",
+			ctrl->ctrl.nr_reconnects);
+	nvme_rdma_reconnect_or_remove(ctrl);
+}
+
+static void nvme_rdma_error_recovery_work(struct work_struct *work)
+{
+	struct nvme_rdma_ctrl *ctrl = container_of(work,
+			struct nvme_rdma_ctrl, err_work);
+
+	nvme_stop_keep_alive(&ctrl->ctrl);
+	flush_work(&ctrl->ctrl.async_event_work);
+	nvme_rdma_teardown_io_queues(ctrl, false);
+	nvme_start_queues(&ctrl->ctrl);
+	nvme_rdma_teardown_admin_queue(ctrl, false);
+
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
+		/* state change failure is ok if we're in DELETING state */
+		WARN_ON_ONCE(ctrl->ctrl.state != NVME_CTRL_DELETING);
+		return;
+	}
+
+	nvme_rdma_reconnect_or_remove(ctrl);
+}
+
+static void nvme_rdma_error_recovery(struct nvme_rdma_ctrl *ctrl)
+{
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING))
+		return;
+
+	queue_work(nvme_wq, &ctrl->err_work);
+}
+
+static void nvme_rdma_wr_error(struct ib_cq *cq, struct ib_wc *wc,
+		const char *op)
+{
+	struct nvme_rdma_queue *queue = cq->cq_context;
+	struct nvme_rdma_ctrl *ctrl = queue->ctrl;
+
+	if (ctrl->ctrl.state == NVME_CTRL_LIVE)
+		dev_info(ctrl->ctrl.device,
+			     "%s for CQE 0x%p failed with status %s (%d)\n",
+			     op, wc->wr_cqe,
+			     ib_wc_status_msg(wc->status), wc->status);
+	nvme_rdma_error_recovery(ctrl);
+}
+
+static void nvme_rdma_memreg_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+	if (unlikely(wc->status != IB_WC_SUCCESS))
+		nvme_rdma_wr_error(cq, wc, "MEMREG");
+}
+
+static void nvme_rdma_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+	struct nvme_rdma_request *req =
+		container_of(wc->wr_cqe, struct nvme_rdma_request, reg_cqe);
+	struct request *rq = blk_mq_rq_from_pdu(req);
+
+	if (unlikely(wc->status != IB_WC_SUCCESS)) {
+		nvme_rdma_wr_error(cq, wc, "LOCAL_INV");
+		return;
+	}
+
+	if (refcount_dec_and_test(&req->ref))
+		nvme_end_request(rq, req->status, req->result);
+
+}
+
+static int nvme_rdma_inv_rkey(struct nvme_rdma_queue *queue,
+		struct nvme_rdma_request *req)
+{
+	struct ib_send_wr wr = {
+		.opcode		    = IB_WR_LOCAL_INV,
+		.next		    = NULL,
+		.num_sge	    = 0,
+		.send_flags	    = IB_SEND_SIGNALED,
+		.ex.invalidate_rkey = req->mr->rkey,
+	};
+
+	req->reg_cqe.done = nvme_rdma_inv_rkey_done;
+	wr.wr_cqe = &req->reg_cqe;
+
+	return ib_post_send(queue->qp, &wr, NULL);
+}
+
+static void nvme_rdma_unmap_data(struct nvme_rdma_queue *queue,
+		struct request *rq)
+{
+	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
+	struct nvme_rdma_device *dev = queue->device;
+	struct ib_device *ibdev = dev->dev;
+
+	if (!blk_rq_payload_bytes(rq))
+		return;
+
+	if (req->mr) {
+		ib_mr_pool_put(queue->qp, &queue->qp->rdma_mrs, req->mr);
+		req->mr = NULL;
+	}
+
+	ib_dma_unmap_sg(ibdev, req->sg_table.sgl,
+			req->nents, rq_data_dir(rq) ==
+				    WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+	nvme_cleanup_cmd(rq);
+	sg_free_table_chained(&req->sg_table, true);
+}
+
+static int nvme_rdma_set_sg_null(struct nvme_command *c)
+{
+	struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;
+
+	sg->addr = 0;
+	put_unaligned_le24(0, sg->length);
+	put_unaligned_le32(0, sg->key);
+	sg->type = NVME_KEY_SGL_FMT_DATA_DESC << 4;
+	return 0;
+}
+
+static int nvme_rdma_map_sg_inline(struct nvme_rdma_queue *queue,
+		struct nvme_rdma_request *req, struct nvme_command *c,
+		int count)
+{
+	struct nvme_sgl_desc *sg = &c->common.dptr.sgl;
+	struct scatterlist *sgl = req->sg_table.sgl;
+	struct ib_sge *sge = &req->sge[1];
+	u32 len = 0;
+	int i;
+
+	for (i = 0; i < count; i++, sgl++, sge++) {
+		sge->addr = sg_dma_address(sgl);
+		sge->length = sg_dma_len(sgl);
+		sge->lkey = queue->device->pd->local_dma_lkey;
+		len += sge->length;
+	}
+
+	sg->addr = cpu_to_le64(queue->ctrl->ctrl.icdoff);
+	sg->length = cpu_to_le32(len);
+	sg->type = (NVME_SGL_FMT_DATA_DESC << 4) | NVME_SGL_FMT_OFFSET;
+
+	req->num_sge += count;
+	return 0;
+}
+
+static int nvme_rdma_map_sg_single(struct nvme_rdma_queue *queue,
+		struct nvme_rdma_request *req, struct nvme_command *c)
+{
+	struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;
+
+	sg->addr = cpu_to_le64(sg_dma_address(req->sg_table.sgl));
+	put_unaligned_le24(sg_dma_len(req->sg_table.sgl), sg->length);
+	put_unaligned_le32(queue->device->pd->unsafe_global_rkey, sg->key);
+	sg->type = NVME_KEY_SGL_FMT_DATA_DESC << 4;
+	return 0;
+}
+
+static int nvme_rdma_map_sg_fr(struct nvme_rdma_queue *queue,
+		struct nvme_rdma_request *req, struct nvme_command *c,
+		int count)
+{
+	struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;
+	int nr;
+
+	req->mr = ib_mr_pool_get(queue->qp, &queue->qp->rdma_mrs);
+	if (WARN_ON_ONCE(!req->mr))
+		return -EAGAIN;
+
+	/*
+	 * Align the MR to a 4K page size to match the ctrl page size and
+	 * the block virtual boundary.
+	 */
+	nr = ib_map_mr_sg(req->mr, req->sg_table.sgl, count, NULL, SZ_4K);
+	if (unlikely(nr < count)) {
+		ib_mr_pool_put(queue->qp, &queue->qp->rdma_mrs, req->mr);
+		req->mr = NULL;
+		if (nr < 0)
+			return nr;
+		return -EINVAL;
+	}
+
+	ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
+
+	req->reg_cqe.done = nvme_rdma_memreg_done;
+	memset(&req->reg_wr, 0, sizeof(req->reg_wr));
+	req->reg_wr.wr.opcode = IB_WR_REG_MR;
+	req->reg_wr.wr.wr_cqe = &req->reg_cqe;
+	req->reg_wr.wr.num_sge = 0;
+	req->reg_wr.mr = req->mr;
+	req->reg_wr.key = req->mr->rkey;
+	req->reg_wr.access = IB_ACCESS_LOCAL_WRITE |
+			     IB_ACCESS_REMOTE_READ |
+			     IB_ACCESS_REMOTE_WRITE;
+
+	sg->addr = cpu_to_le64(req->mr->iova);
+	put_unaligned_le24(req->mr->length, sg->length);
+	put_unaligned_le32(req->mr->rkey, sg->key);
+	sg->type = (NVME_KEY_SGL_FMT_DATA_DESC << 4) |
+			NVME_SGL_FMT_INVALIDATE;
+
+	return 0;
+}
+
+static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
+		struct request *rq, struct nvme_command *c)
+{
+	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
+	struct nvme_rdma_device *dev = queue->device;
+	struct ib_device *ibdev = dev->dev;
+	int count, ret;
+
+	req->num_sge = 1;
+	refcount_set(&req->ref, 2); /* send and recv completions */
+
+	c->common.flags |= NVME_CMD_SGL_METABUF;
+
+	if (!blk_rq_payload_bytes(rq))
+		return nvme_rdma_set_sg_null(c);
+
+	req->sg_table.sgl = req->first_sgl;
+	ret = sg_alloc_table_chained(&req->sg_table,
+			blk_rq_nr_phys_segments(rq), req->sg_table.sgl);
+	if (ret)
+		return -ENOMEM;
+
+	req->nents = blk_rq_map_sg(rq->q, rq, req->sg_table.sgl);
+
+	count = ib_dma_map_sg(ibdev, req->sg_table.sgl, req->nents,
+		    rq_data_dir(rq) == WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+	if (unlikely(count <= 0)) {
+		ret = -EIO;
+		goto out_free_table;
+	}
+
+	if (count <= dev->num_inline_segments) {
+		if (rq_data_dir(rq) == WRITE && nvme_rdma_queue_idx(queue) &&
+		    queue->ctrl->use_inline_data &&
+		    blk_rq_payload_bytes(rq) <=
+				nvme_rdma_inline_data_size(queue)) {
+			ret = nvme_rdma_map_sg_inline(queue, req, c, count);
+			goto out;
+		}
+
+		if (count == 1 && dev->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY) {
+			ret = nvme_rdma_map_sg_single(queue, req, c);
+			goto out;
+		}
+	}
+
+	ret = nvme_rdma_map_sg_fr(queue, req, c, count);
+out:
+	if (unlikely(ret))
+		goto out_unmap_sg;
+
+	return 0;
+
+out_unmap_sg:
+	ib_dma_unmap_sg(ibdev, req->sg_table.sgl,
+			req->nents, rq_data_dir(rq) ==
+			WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+out_free_table:
+	sg_free_table_chained(&req->sg_table, true);
+	return ret;
+}
+
+static void nvme_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+	struct nvme_rdma_qe *qe =
+		container_of(wc->wr_cqe, struct nvme_rdma_qe, cqe);
+	struct nvme_rdma_request *req =
+		container_of(qe, struct nvme_rdma_request, sqe);
+	struct request *rq = blk_mq_rq_from_pdu(req);
+
+	if (unlikely(wc->status != IB_WC_SUCCESS)) {
+		nvme_rdma_wr_error(cq, wc, "SEND");
+		return;
+	}
+
+	if (refcount_dec_and_test(&req->ref))
+		nvme_end_request(rq, req->status, req->result);
+}
+
+static int nvme_rdma_post_send(struct nvme_rdma_queue *queue,
+		struct nvme_rdma_qe *qe, struct ib_sge *sge, u32 num_sge,
+		struct ib_send_wr *first)
+{
+	struct ib_send_wr wr;
+	int ret;
+
+	sge->addr   = qe->dma;
+	sge->length = sizeof(struct nvme_command),
+	sge->lkey   = queue->device->pd->local_dma_lkey;
+
+	wr.next       = NULL;
+	wr.wr_cqe     = &qe->cqe;
+	wr.sg_list    = sge;
+	wr.num_sge    = num_sge;
+	wr.opcode     = IB_WR_SEND;
+	wr.send_flags = IB_SEND_SIGNALED;
+
+	if (first)
+		first->next = &wr;
+	else
+		first = &wr;
+
+	ret = ib_post_send(queue->qp, first, NULL);
+	if (unlikely(ret)) {
+		dev_err(queue->ctrl->ctrl.device,
+			     "%s failed with error code %d\n", __func__, ret);
+	}
+	return ret;
+}
+
+static int nvme_rdma_post_recv(struct nvme_rdma_queue *queue,
+		struct nvme_rdma_qe *qe)
+{
+	struct ib_recv_wr wr;
+	struct ib_sge list;
+	int ret;
+
+	list.addr   = qe->dma;
+	list.length = sizeof(struct nvme_completion);
+	list.lkey   = queue->device->pd->local_dma_lkey;
+
+	qe->cqe.done = nvme_rdma_recv_done;
+
+	wr.next     = NULL;
+	wr.wr_cqe   = &qe->cqe;
+	wr.sg_list  = &list;
+	wr.num_sge  = 1;
+
+	ret = ib_post_recv(queue->qp, &wr, NULL);
+	if (unlikely(ret)) {
+		dev_err(queue->ctrl->ctrl.device,
+			"%s failed with error code %d\n", __func__, ret);
+	}
+	return ret;
+}
+
+static struct blk_mq_tags *nvme_rdma_tagset(struct nvme_rdma_queue *queue)
+{
+	u32 queue_idx = nvme_rdma_queue_idx(queue);
+
+	if (queue_idx == 0)
+		return queue->ctrl->admin_tag_set.tags[queue_idx];
+	return queue->ctrl->tag_set.tags[queue_idx - 1];
+}
+
+static void nvme_rdma_async_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+	if (unlikely(wc->status != IB_WC_SUCCESS))
+		nvme_rdma_wr_error(cq, wc, "ASYNC");
+}
+
+static void nvme_rdma_submit_async_event(struct nvme_ctrl *arg)
+{
+	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(arg);
+	struct nvme_rdma_queue *queue = &ctrl->queues[0];
+	struct ib_device *dev = queue->device->dev;
+	struct nvme_rdma_qe *sqe = &ctrl->async_event_sqe;
+	struct nvme_command *cmd = sqe->data;
+	struct ib_sge sge;
+	int ret;
+
+	ib_dma_sync_single_for_cpu(dev, sqe->dma, sizeof(*cmd), DMA_TO_DEVICE);
+
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->common.opcode = nvme_admin_async_event;
+	cmd->common.command_id = NVME_AQ_BLK_MQ_DEPTH;
+	cmd->common.flags |= NVME_CMD_SGL_METABUF;
+	nvme_rdma_set_sg_null(cmd);
+
+	sqe->cqe.done = nvme_rdma_async_done;
+
+	ib_dma_sync_single_for_device(dev, sqe->dma, sizeof(*cmd),
+			DMA_TO_DEVICE);
+
+	ret = nvme_rdma_post_send(queue, sqe, &sge, 1, NULL);
+	WARN_ON_ONCE(ret);
+}
+
+static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
+		struct nvme_completion *cqe, struct ib_wc *wc, int tag)
+{
+	struct request *rq;
+	struct nvme_rdma_request *req;
+	int ret = 0;
+
+	rq = blk_mq_tag_to_rq(nvme_rdma_tagset(queue), cqe->command_id);
+	if (!rq) {
+		dev_err(queue->ctrl->ctrl.device,
+			"tag 0x%x on QP %#x not found\n",
+			cqe->command_id, queue->qp->qp_num);
+		nvme_rdma_error_recovery(queue->ctrl);
+		return ret;
+	}
+	req = blk_mq_rq_to_pdu(rq);
+
+	req->status = cqe->status;
+	req->result = cqe->result;
+
+	if (wc->wc_flags & IB_WC_WITH_INVALIDATE) {
+		if (unlikely(wc->ex.invalidate_rkey != req->mr->rkey)) {
+			dev_err(queue->ctrl->ctrl.device,
+				"Bogus remote invalidation for rkey %#x\n",
+				req->mr->rkey);
+			nvme_rdma_error_recovery(queue->ctrl);
+		}
+	} else if (req->mr) {
+		ret = nvme_rdma_inv_rkey(queue, req);
+		if (unlikely(ret < 0)) {
+			dev_err(queue->ctrl->ctrl.device,
+				"Queueing INV WR for rkey %#x failed (%d)\n",
+				req->mr->rkey, ret);
+			nvme_rdma_error_recovery(queue->ctrl);
+		}
+		/* the local invalidation completion will end the request */
+		return 0;
+	}
+
+	if (refcount_dec_and_test(&req->ref)) {
+		if (rq->tag == tag)
+			ret = 1;
+		nvme_end_request(rq, req->status, req->result);
+	}
+
+	return ret;
+}
+
+static int __nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc, int tag)
+{
+	struct nvme_rdma_qe *qe =
+		container_of(wc->wr_cqe, struct nvme_rdma_qe, cqe);
+	struct nvme_rdma_queue *queue = cq->cq_context;
+	struct ib_device *ibdev = queue->device->dev;
+	struct nvme_completion *cqe = qe->data;
+	const size_t len = sizeof(struct nvme_completion);
+	int ret = 0;
+
+	if (unlikely(wc->status != IB_WC_SUCCESS)) {
+		nvme_rdma_wr_error(cq, wc, "RECV");
+		return 0;
+	}
+
+	ib_dma_sync_single_for_cpu(ibdev, qe->dma, len, DMA_FROM_DEVICE);
+	/*
+	 * AEN requests are special as they don't time out and can
+	 * survive any kind of queue freeze and often don't respond to
+	 * aborts.  We don't even bother to allocate a struct request
+	 * for them but rather special case them here.
+	 */
+	if (unlikely(nvme_rdma_queue_idx(queue) == 0 &&
+			cqe->command_id >= NVME_AQ_BLK_MQ_DEPTH))
+		nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
+				&cqe->result);
+	else
+		ret = nvme_rdma_process_nvme_rsp(queue, cqe, wc, tag);
+	ib_dma_sync_single_for_device(ibdev, qe->dma, len, DMA_FROM_DEVICE);
+
+	nvme_rdma_post_recv(queue, qe);
+	return ret;
+}
+
+static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+	__nvme_rdma_recv_done(cq, wc, -1);
+}
+
+static int nvme_rdma_conn_established(struct nvme_rdma_queue *queue)
+{
+	int ret, i;
+
+	for (i = 0; i < queue->queue_size; i++) {
+		ret = nvme_rdma_post_recv(queue, &queue->rsp_ring[i]);
+		if (ret)
+			goto out_destroy_queue_ib;
+	}
+
+	return 0;
+
+out_destroy_queue_ib:
+	nvme_rdma_destroy_queue_ib(queue);
+	return ret;
+}
+
+static int nvme_rdma_conn_rejected(struct nvme_rdma_queue *queue,
+		struct rdma_cm_event *ev)
+{
+	struct rdma_cm_id *cm_id = queue->cm_id;
+	int status = ev->status;
+	const char *rej_msg;
+	const struct nvme_rdma_cm_rej *rej_data;
+	u8 rej_data_len;
+
+	rej_msg = rdma_reject_msg(cm_id, status);
+	rej_data = rdma_consumer_reject_data(cm_id, ev, &rej_data_len);
+
+	if (rej_data && rej_data_len >= sizeof(u16)) {
+		u16 sts = le16_to_cpu(rej_data->sts);
+
+		dev_err(queue->ctrl->ctrl.device,
+		      "Connect rejected: status %d (%s) nvme status %d (%s).\n",
+		      status, rej_msg, sts, nvme_rdma_cm_msg(sts));
+	} else {
+		dev_err(queue->ctrl->ctrl.device,
+			"Connect rejected: status %d (%s).\n", status, rej_msg);
+	}
+
+	return -ECONNRESET;
+}
+
+static int nvme_rdma_addr_resolved(struct nvme_rdma_queue *queue)
+{
+	int ret;
+
+	ret = nvme_rdma_create_queue_ib(queue);
+	if (ret)
+		return ret;
+
+	ret = rdma_resolve_route(queue->cm_id, NVME_RDMA_CONNECT_TIMEOUT_MS);
+	if (ret) {
+		dev_err(queue->ctrl->ctrl.device,
+			"rdma_resolve_route failed (%d).\n",
+			queue->cm_error);
+		goto out_destroy_queue;
+	}
+
+	return 0;
+
+out_destroy_queue:
+	nvme_rdma_destroy_queue_ib(queue);
+	return ret;
+}
+
+static int nvme_rdma_route_resolved(struct nvme_rdma_queue *queue)
+{
+	struct nvme_rdma_ctrl *ctrl = queue->ctrl;
+	struct rdma_conn_param param = { };
+	struct nvme_rdma_cm_req priv = { };
+	int ret;
+
+	param.qp_num = queue->qp->qp_num;
+	param.flow_control = 1;
+
+	param.responder_resources = queue->device->dev->attrs.max_qp_rd_atom;
+	/* maximum retry count */
+	param.retry_count = 7;
+	param.rnr_retry_count = 7;
+	param.private_data = &priv;
+	param.private_data_len = sizeof(priv);
+
+	priv.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
+	priv.qid = cpu_to_le16(nvme_rdma_queue_idx(queue));
+	/*
+	 * set the admin queue depth to the minimum size
+	 * specified by the Fabrics standard.
+	 */
+	if (priv.qid == 0) {
+		priv.hrqsize = cpu_to_le16(NVME_AQ_DEPTH);
+		priv.hsqsize = cpu_to_le16(NVME_AQ_DEPTH - 1);
+	} else {
+		/*
+		 * current interpretation of the fabrics spec
+		 * is at minimum you make hrqsize sqsize+1, or a
+		 * 1's based representation of sqsize.
+		 */
+		priv.hrqsize = cpu_to_le16(queue->queue_size);
+		priv.hsqsize = cpu_to_le16(queue->ctrl->ctrl.sqsize);
+	}
+
+	ret = rdma_connect(queue->cm_id, &param);
+	if (ret) {
+		dev_err(ctrl->ctrl.device,
+			"rdma_connect failed (%d).\n", ret);
+		goto out_destroy_queue_ib;
+	}
+
+	return 0;
+
+out_destroy_queue_ib:
+	nvme_rdma_destroy_queue_ib(queue);
+	return ret;
+}
+
+static int nvme_rdma_cm_handler(struct rdma_cm_id *cm_id,
+		struct rdma_cm_event *ev)
+{
+	struct nvme_rdma_queue *queue = cm_id->context;
+	int cm_error = 0;
+
+	dev_dbg(queue->ctrl->ctrl.device, "%s (%d): status %d id %p\n",
+		rdma_event_msg(ev->event), ev->event,
+		ev->status, cm_id);
+
+	switch (ev->event) {
+	case RDMA_CM_EVENT_ADDR_RESOLVED:
+		cm_error = nvme_rdma_addr_resolved(queue);
+		break;
+	case RDMA_CM_EVENT_ROUTE_RESOLVED:
+		cm_error = nvme_rdma_route_resolved(queue);
+		break;
+	case RDMA_CM_EVENT_ESTABLISHED:
+		queue->cm_error = nvme_rdma_conn_established(queue);
+		/* complete cm_done regardless of success/failure */
+		complete(&queue->cm_done);
+		return 0;
+	case RDMA_CM_EVENT_REJECTED:
+		cm_error = nvme_rdma_conn_rejected(queue, ev);
+		break;
+	case RDMA_CM_EVENT_ROUTE_ERROR:
+	case RDMA_CM_EVENT_CONNECT_ERROR:
+	case RDMA_CM_EVENT_UNREACHABLE:
+		nvme_rdma_destroy_queue_ib(queue);
+		/* fall through */
+	case RDMA_CM_EVENT_ADDR_ERROR:
+		dev_dbg(queue->ctrl->ctrl.device,
+			"CM error event %d\n", ev->event);
+		cm_error = -ECONNRESET;
+		break;
+	case RDMA_CM_EVENT_DISCONNECTED:
+	case RDMA_CM_EVENT_ADDR_CHANGE:
+	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
+		dev_dbg(queue->ctrl->ctrl.device,
+			"disconnect received - connection closed\n");
+		nvme_rdma_error_recovery(queue->ctrl);
+		break;
+	case RDMA_CM_EVENT_DEVICE_REMOVAL:
+		/* device removal is handled via the ib_client API */
+		break;
+	default:
+		dev_err(queue->ctrl->ctrl.device,
+			"Unexpected RDMA CM event (%d)\n", ev->event);
+		nvme_rdma_error_recovery(queue->ctrl);
+		break;
+	}
+
+	if (cm_error) {
+		queue->cm_error = cm_error;
+		complete(&queue->cm_done);
+	}
+
+	return 0;
+}
+
+static enum blk_eh_timer_return
+nvme_rdma_timeout(struct request *rq, bool reserved)
+{
+	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
+	struct nvme_rdma_queue *queue = req->queue;
+	struct nvme_rdma_ctrl *ctrl = queue->ctrl;
+
+	dev_warn(ctrl->ctrl.device, "I/O %d QID %d timeout\n",
+		 rq->tag, nvme_rdma_queue_idx(queue));
+
+	if (ctrl->ctrl.state != NVME_CTRL_LIVE) {
+		/*
+		 * Teardown immediately if controller times out while starting
+		 * or we are already started error recovery. all outstanding
+		 * requests are completed on shutdown, so we return BLK_EH_DONE.
+		 */
+		flush_work(&ctrl->err_work);
+		nvme_rdma_teardown_io_queues(ctrl, false);
+		nvme_rdma_teardown_admin_queue(ctrl, false);
+		return BLK_EH_DONE;
+	}
+
+	dev_warn(ctrl->ctrl.device, "starting error recovery\n");
+	nvme_rdma_error_recovery(ctrl);
+
+	return BLK_EH_RESET_TIMER;
+}
+
+static blk_status_t nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
+		const struct blk_mq_queue_data *bd)
+{
+	struct nvme_ns *ns = hctx->queue->queuedata;
+	struct nvme_rdma_queue *queue = hctx->driver_data;
+	struct request *rq = bd->rq;
+	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
+	struct nvme_rdma_qe *sqe = &req->sqe;
+	struct nvme_command *c = sqe->data;
+	struct ib_device *dev;
+	bool queue_ready = test_bit(NVME_RDMA_Q_LIVE, &queue->flags);
+	blk_status_t ret;
+	int err;
+
+	WARN_ON_ONCE(rq->tag < 0);
+
+	if (!nvmf_check_ready(&queue->ctrl->ctrl, rq, queue_ready))
+		return nvmf_fail_nonready_command(&queue->ctrl->ctrl, rq);
+
+	dev = queue->device->dev;
+	ib_dma_sync_single_for_cpu(dev, sqe->dma,
+			sizeof(struct nvme_command), DMA_TO_DEVICE);
+
+	ret = nvme_setup_cmd(ns, rq, c);
+	if (ret)
+		return ret;
+
+	blk_mq_start_request(rq);
+
+	err = nvme_rdma_map_data(queue, rq, c);
+	if (unlikely(err < 0)) {
+		dev_err(queue->ctrl->ctrl.device,
+			     "Failed to map data (%d)\n", err);
+		nvme_cleanup_cmd(rq);
+		goto err;
+	}
+
+	sqe->cqe.done = nvme_rdma_send_done;
+
+	ib_dma_sync_single_for_device(dev, sqe->dma,
+			sizeof(struct nvme_command), DMA_TO_DEVICE);
+
+	err = nvme_rdma_post_send(queue, sqe, req->sge, req->num_sge,
+			req->mr ? &req->reg_wr.wr : NULL);
+	if (unlikely(err)) {
+		nvme_rdma_unmap_data(queue, rq);
+		goto err;
+	}
+
+	return BLK_STS_OK;
+err:
+	if (err == -ENOMEM || err == -EAGAIN)
+		return BLK_STS_RESOURCE;
+	return BLK_STS_IOERR;
+}
+
+static int nvme_rdma_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
+{
+	struct nvme_rdma_queue *queue = hctx->driver_data;
+	struct ib_cq *cq = queue->ib_cq;
+	struct ib_wc wc;
+	int found = 0;
+
+	while (ib_poll_cq(cq, 1, &wc) > 0) {
+		struct ib_cqe *cqe = wc.wr_cqe;
+
+		if (cqe) {
+			if (cqe->done == nvme_rdma_recv_done)
+				found |= __nvme_rdma_recv_done(cq, &wc, tag);
+			else
+				cqe->done(cq, &wc);
+		}
+	}
+
+	return found;
+}
+
+static void nvme_rdma_complete_rq(struct request *rq)
+{
+	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
+
+	nvme_rdma_unmap_data(req->queue, rq);
+	nvme_complete_rq(rq);
+}
+
+static int nvme_rdma_map_queues(struct blk_mq_tag_set *set)
+{
+	struct nvme_rdma_ctrl *ctrl = set->driver_data;
+
+	return blk_mq_rdma_map_queues(set, ctrl->device->dev, 0);
+}
+
+static const struct blk_mq_ops nvme_rdma_mq_ops = {
+	.queue_rq	= nvme_rdma_queue_rq,
+	.complete	= nvme_rdma_complete_rq,
+	.init_request	= nvme_rdma_init_request,
+	.exit_request	= nvme_rdma_exit_request,
+	.init_hctx	= nvme_rdma_init_hctx,
+	.poll		= nvme_rdma_poll,
+	.timeout	= nvme_rdma_timeout,
+	.map_queues	= nvme_rdma_map_queues,
+};
+
+static const struct blk_mq_ops nvme_rdma_admin_mq_ops = {
+	.queue_rq	= nvme_rdma_queue_rq,
+	.complete	= nvme_rdma_complete_rq,
+	.init_request	= nvme_rdma_init_request,
+	.exit_request	= nvme_rdma_exit_request,
+	.init_hctx	= nvme_rdma_init_admin_hctx,
+	.timeout	= nvme_rdma_timeout,
+};
+
+static void nvme_rdma_shutdown_ctrl(struct nvme_rdma_ctrl *ctrl, bool shutdown)
+{
+	nvme_rdma_teardown_io_queues(ctrl, shutdown);
+	if (shutdown)
+		nvme_shutdown_ctrl(&ctrl->ctrl);
+	else
+		nvme_disable_ctrl(&ctrl->ctrl, ctrl->ctrl.cap);
+	nvme_rdma_teardown_admin_queue(ctrl, shutdown);
+}
+
+static void nvme_rdma_delete_ctrl(struct nvme_ctrl *ctrl)
+{
+	nvme_rdma_shutdown_ctrl(to_rdma_ctrl(ctrl), true);
+}
+
+static void nvme_rdma_reset_ctrl_work(struct work_struct *work)
+{
+	struct nvme_rdma_ctrl *ctrl =
+		container_of(work, struct nvme_rdma_ctrl, ctrl.reset_work);
+
+	nvme_stop_ctrl(&ctrl->ctrl);
+	nvme_rdma_shutdown_ctrl(ctrl, false);
+
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
+		/* state change failure should never happen */
+		WARN_ON_ONCE(1);
+		return;
+	}
+
+	if (nvme_rdma_setup_ctrl(ctrl, false))
+		goto out_fail;
+
+	return;
+
+out_fail:
+	++ctrl->ctrl.nr_reconnects;
+	nvme_rdma_reconnect_or_remove(ctrl);
+}
+
+static const struct nvme_ctrl_ops nvme_rdma_ctrl_ops = {
+	.name			= "rdma",
+	.module			= THIS_MODULE,
+	.flags			= NVME_F_FABRICS,
+	.reg_read32		= nvmf_reg_read32,
+	.reg_read64		= nvmf_reg_read64,
+	.reg_write32		= nvmf_reg_write32,
+	.free_ctrl		= nvme_rdma_free_ctrl,
+	.submit_async_event	= nvme_rdma_submit_async_event,
+	.delete_ctrl		= nvme_rdma_delete_ctrl,
+	.get_address		= nvmf_get_address,
+	.stop_ctrl		= nvme_rdma_stop_ctrl,
+};
+
+static inline bool
+__nvme_rdma_options_match(struct nvme_rdma_ctrl *ctrl,
+	struct nvmf_ctrl_options *opts)
+{
+	char *stdport = __stringify(NVME_RDMA_IP_PORT);
+
+
+	if (!nvmf_ctlr_matches_baseopts(&ctrl->ctrl, opts) ||
+	    strcmp(opts->traddr, ctrl->ctrl.opts->traddr))
+		return false;
+
+	if (opts->mask & NVMF_OPT_TRSVCID &&
+	    ctrl->ctrl.opts->mask & NVMF_OPT_TRSVCID) {
+		if (strcmp(opts->trsvcid, ctrl->ctrl.opts->trsvcid))
+			return false;
+	} else if (opts->mask & NVMF_OPT_TRSVCID) {
+		if (strcmp(opts->trsvcid, stdport))
+			return false;
+	} else if (ctrl->ctrl.opts->mask & NVMF_OPT_TRSVCID) {
+		if (strcmp(stdport, ctrl->ctrl.opts->trsvcid))
+			return false;
+	}
+	/* else, it's a match as both have stdport. Fall to next checks */
+
+	/*
+	 * checking the local address is rough. In most cases, one
+	 * is not specified and the host port is selected by the stack.
+	 *
+	 * Assume no match if:
+	 *  local address is specified and address is not the same
+	 *  local address is not specified but remote is, or vice versa
+	 *    (admin using specific host_traddr when it matters).
+	 */
+	if (opts->mask & NVMF_OPT_HOST_TRADDR &&
+	    ctrl->ctrl.opts->mask & NVMF_OPT_HOST_TRADDR) {
+		if (strcmp(opts->host_traddr, ctrl->ctrl.opts->host_traddr))
+			return false;
+	} else if (opts->mask & NVMF_OPT_HOST_TRADDR ||
+		   ctrl->ctrl.opts->mask & NVMF_OPT_HOST_TRADDR)
+		return false;
+	/*
+	 * if neither controller had an host port specified, assume it's
+	 * a match as everything else matched.
+	 */
+
+	return true;
+}
+
+/*
+ * Fails a connection request if it matches an existing controller
+ * (association) with the same tuple:
+ * <Host NQN, Host ID, local address, remote address, remote port, SUBSYS NQN>
+ *
+ * if local address is not specified in the request, it will match an
+ * existing controller with all the other parameters the same and no
+ * local port address specified as well.
+ *
+ * The ports don't need to be compared as they are intrinsically
+ * already matched by the port pointers supplied.
+ */
+static bool
+nvme_rdma_existing_controller(struct nvmf_ctrl_options *opts)
+{
+	struct nvme_rdma_ctrl *ctrl;
+	bool found = false;
+
+	mutex_lock(&nvme_rdma_ctrl_mutex);
+	list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list) {
+		found = __nvme_rdma_options_match(ctrl, opts);
+		if (found)
+			break;
+	}
+	mutex_unlock(&nvme_rdma_ctrl_mutex);
+
+	return found;
+}
+
+static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev,
+		struct nvmf_ctrl_options *opts)
+{
+	struct nvme_rdma_ctrl *ctrl;
+	int ret;
+	bool changed;
+	char *port;
+
+	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return ERR_PTR(-ENOMEM);
+	ctrl->ctrl.opts = opts;
+	INIT_LIST_HEAD(&ctrl->list);
+	mutex_init(&ctrl->teardown_lock);
+
+	if (opts->mask & NVMF_OPT_TRSVCID)
+		port = opts->trsvcid;
+	else
+		port = __stringify(NVME_RDMA_IP_PORT);
+
+	ret = inet_pton_with_scope(&init_net, AF_UNSPEC,
+			opts->traddr, port, &ctrl->addr);
+	if (ret) {
+		pr_err("malformed address passed: %s:%s\n", opts->traddr, port);
+		goto out_free_ctrl;
+	}
+
+	if (opts->mask & NVMF_OPT_HOST_TRADDR) {
+		ret = inet_pton_with_scope(&init_net, AF_UNSPEC,
+			opts->host_traddr, NULL, &ctrl->src_addr);
+		if (ret) {
+			pr_err("malformed src address passed: %s\n",
+			       opts->host_traddr);
+			goto out_free_ctrl;
+		}
+	}
+
+	if (!opts->duplicate_connect && nvme_rdma_existing_controller(opts)) {
+		ret = -EALREADY;
+		goto out_free_ctrl;
+	}
+
+	INIT_DELAYED_WORK(&ctrl->reconnect_work,
+			nvme_rdma_reconnect_ctrl_work);
+	INIT_WORK(&ctrl->err_work, nvme_rdma_error_recovery_work);
+	INIT_WORK(&ctrl->ctrl.reset_work, nvme_rdma_reset_ctrl_work);
+
+	ctrl->ctrl.queue_count = opts->nr_io_queues + 1; /* +1 for admin queue */
+	ctrl->ctrl.sqsize = opts->queue_size - 1;
+	ctrl->ctrl.kato = opts->kato;
+
+	ret = -ENOMEM;
+	ctrl->queues = kcalloc(ctrl->ctrl.queue_count, sizeof(*ctrl->queues),
+				GFP_KERNEL);
+	if (!ctrl->queues)
+		goto out_free_ctrl;
+
+	ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_rdma_ctrl_ops,
+				0 /* no quirks, we're perfect! */);
+	if (ret)
+		goto out_kfree_queues;
+
+	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING);
+	WARN_ON_ONCE(!changed);
+
+	ret = nvme_rdma_setup_ctrl(ctrl, true);
+	if (ret)
+		goto out_uninit_ctrl;
+
+	dev_info(ctrl->ctrl.device, "new ctrl: NQN \"%s\", addr %pISpcs\n",
+		ctrl->ctrl.opts->subsysnqn, &ctrl->addr);
+
+	nvme_get_ctrl(&ctrl->ctrl);
+
+	mutex_lock(&nvme_rdma_ctrl_mutex);
+	list_add_tail(&ctrl->list, &nvme_rdma_ctrl_list);
+	mutex_unlock(&nvme_rdma_ctrl_mutex);
+
+	return &ctrl->ctrl;
+
+out_uninit_ctrl:
+	nvme_uninit_ctrl(&ctrl->ctrl);
+	nvme_put_ctrl(&ctrl->ctrl);
+	if (ret > 0)
+		ret = -EIO;
+	return ERR_PTR(ret);
+out_kfree_queues:
+	kfree(ctrl->queues);
+out_free_ctrl:
+	kfree(ctrl);
+	return ERR_PTR(ret);
+}
+
+static struct nvmf_transport_ops nvme_rdma_transport = {
+	.name		= "rdma",
+	.module		= THIS_MODULE,
+	.required_opts	= NVMF_OPT_TRADDR,
+	.allowed_opts	= NVMF_OPT_TRSVCID | NVMF_OPT_RECONNECT_DELAY |
+			  NVMF_OPT_HOST_TRADDR | NVMF_OPT_CTRL_LOSS_TMO,
+	.create_ctrl	= nvme_rdma_create_ctrl,
+};
+
+static void nvme_rdma_remove_one(struct ib_device *ib_device, void *client_data)
+{
+	struct nvme_rdma_ctrl *ctrl;
+	struct nvme_rdma_device *ndev;
+	bool found = false;
+
+	mutex_lock(&device_list_mutex);
+	list_for_each_entry(ndev, &device_list, entry) {
+		if (ndev->dev == ib_device) {
+			found = true;
+			break;
+		}
+	}
+	mutex_unlock(&device_list_mutex);
+
+	if (!found)
+		return;
+
+	/* Delete all controllers using this device */
+	mutex_lock(&nvme_rdma_ctrl_mutex);
+	list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list) {
+		if (ctrl->device->dev != ib_device)
+			continue;
+		nvme_delete_ctrl(&ctrl->ctrl);
+	}
+	mutex_unlock(&nvme_rdma_ctrl_mutex);
+
+	flush_workqueue(nvme_delete_wq);
+}
+
+static struct ib_client nvme_rdma_ib_client = {
+	.name   = "nvme_rdma",
+	.remove = nvme_rdma_remove_one
+};
+
+static int __init nvme_rdma_init_module(void)
+{
+	int ret;
+
+	ret = ib_register_client(&nvme_rdma_ib_client);
+	if (ret)
+		return ret;
+
+	ret = nvmf_register_transport(&nvme_rdma_transport);
+	if (ret)
+		goto err_unreg_client;
+
+	return 0;
+
+err_unreg_client:
+	ib_unregister_client(&nvme_rdma_ib_client);
+	return ret;
+}
+
+static void __exit nvme_rdma_cleanup_module(void)
+{
+	nvmf_unregister_transport(&nvme_rdma_transport);
+	ib_unregister_client(&nvme_rdma_ib_client);
+}
+
+module_init(nvme_rdma_init_module);
+module_exit(nvme_rdma_cleanup_module);
+
+MODULE_LICENSE("GPL v2");