text: /*
   * 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;
  	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);
  		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)
  {
  	int ret;
  
  	ret = wait_for_completion_interruptible_timeout(&queue->cm_done,
  			msecs_to_jiffies(NVME_RDMA_CONNECT_TIMEOUT_MS) + 1);
  	if (ret < 0)
  		return ret;
  	if (ret == 0)
  		return -ETIMEDOUT;
  	WARN_ON_ONCE(queue->cm_error > 0);
  	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;
  
  	/* +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;
  
  	ctrl->ctrl.queue_count = nr_io_queues + 1;
  	if (ctrl->ctrl.queue_count < 2)
  		return 0;
  
  	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) {
  		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:
  	nvme_rdma_free_qe(ctrl->device->dev, &ctrl->async_event_sqe,
  		sizeof(struct nvme_command), DMA_TO_DEVICE);
  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)
  {
  	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
  	nvme_rdma_stop_queue(&ctrl->queues[0]);
  	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set, nvme_cancel_request,
  			&ctrl->ctrl);
  	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
  	nvme_rdma_destroy_admin_queue(ctrl, remove);
  }
  
  static void nvme_rdma_teardown_io_queues(struct nvme_rdma_ctrl *ctrl,
  		bool remove)
  {
  	if (ctrl->ctrl.queue_count > 1) {
  		nvme_stop_queues(&ctrl->ctrl);
  		nvme_rdma_stop_io_queues(ctrl);
  		blk_mq_tagset_busy_iter(&ctrl->tag_set, nvme_cancel_request,
  				&ctrl->ctrl);
  		if (remove)
  			nvme_start_queues(&ctrl->ctrl);
  		nvme_rdma_destroy_io_queues(ctrl, remove);
  	}
  }
  
  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) {
  		dev_err(ctrl->ctrl.device, "icdoff is not supported!\n");
  		goto destroy_admin;
  	}
  
  	if (!(ctrl->ctrl.sgls & (1 << 2))) {
  		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);
  	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:
  		nvme_rdma_destroy_queue_ib(queue);
  		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);
  
  	dev_warn(req->queue->ctrl->ctrl.device,
  		 "I/O %d QID %d timeout, reset controller\n",
  		 rq->tag, nvme_rdma_queue_idx(req->queue));
  
  	/* queue error recovery */
  	nvme_rdma_error_recovery(req->queue->ctrl);
  
  	/* fail with DNR on cmd timeout */
  	nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
  
  	return BLK_EH_DONE;
  }
  
  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,
  };
  
  /*
   * 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 = nvmf_ip_options_match(&ctrl->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;
  
  	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
  	if (!ctrl)
  		return ERR_PTR(-ENOMEM);
  	ctrl->ctrl.opts = opts;
  	INIT_LIST_HEAD(&ctrl->list);
  
  	if (!(opts->mask & NVMF_OPT_TRSVCID)) {
  		opts->trsvcid =
  			kstrdup(__stringify(NVME_RDMA_IP_PORT), GFP_KERNEL);
  		if (!opts->trsvcid) {
  			ret = -ENOMEM;
  			goto out_free_ctrl;
  		}
  		opts->mask |= NVMF_OPT_TRSVCID;
  	}
  
  	ret = inet_pton_with_scope(&init_net, AF_UNSPEC,
  			opts->traddr, opts->trsvcid, &ctrl->addr);
  	if (ret) {
  		pr_err("malformed address passed: %s:%s\n",
  			opts->traddr, opts->trsvcid);
  		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");
  