[PATCH 5/5] nvme-rdma: add a NVMe over Fabrics RDMA host driver

Sagi Grimberg sagi at lightbits.io
Tue Jun 7 05:00:53 PDT 2016


We forgot to CC Linux-rdma, CC'ing...

On 07/06/16 00:23, Christoph Hellwig wrote:
> This patch implements the RDMA host (initiator in SCSI speak) driver.  It
> can be used to connect to remote NVMe over Fabrics controllers over
> Infiniband, RoCE or iWarp, and uses the existing NVMe core driver as well
> a the new fabrics library.
>
> To connect to all NVMe over Fabrics controller reachable on a given taget
> port using RDMA/CM use the following command:
>
> 	nvme connect-all -t rdma -a $IPADDR
>
> This requires the latest version of nvme-cli with Fabrics support.
>
> Signed-off-by: Jay Freyensee <james.p.freyensee at intel.com>
> Signed-off-by: Ming Lin <ming.l at ssi.samsung.com>
> Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>   drivers/nvme/host/Kconfig  |   16 +
>   drivers/nvme/host/Makefile |    3 +
>   drivers/nvme/host/rdma.c   | 2009 ++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 2028 insertions(+)
>   create mode 100644 drivers/nvme/host/rdma.c
>
> diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig
> index 3397651..db39d53 100644
> --- a/drivers/nvme/host/Kconfig
> +++ b/drivers/nvme/host/Kconfig
> @@ -27,3 +27,19 @@ config BLK_DEV_NVME_SCSI
>
>   config NVME_FABRICS
>   	tristate
> +
> +config NVME_RDMA
> +	tristate "NVM Express over Fabrics RDMA host driver"
> +	depends on INFINIBAND
> +	depends on BLK_DEV_NVME
> +	select NVME_FABRICS
> +	select SG_POOL
> +	help
> +	  This provides support for the NVMe over Fabrics protocol using
> +	  the RDMA (Infiniband, RoCE, iWarp) transport.  This allows you
> +	  to use remote block devices exported using the NVMe protocol set.
> +
> +	  To configure a NVMe over Fabrics controller use the nvme-cli tool
> +	  from https://github.com/linux-nvme/nvme-cli.
> +
> +	  If unsure, say N.
> diff --git a/drivers/nvme/host/Makefile b/drivers/nvme/host/Makefile
> index 5f8648f..47abcec 100644
> --- a/drivers/nvme/host/Makefile
> +++ b/drivers/nvme/host/Makefile
> @@ -1,6 +1,7 @@
>   obj-$(CONFIG_NVME_CORE)			+= nvme-core.o
>   obj-$(CONFIG_BLK_DEV_NVME)		+= nvme.o
>   obj-$(CONFIG_NVME_FABRICS)		+= nvme-fabrics.o
> +obj-$(CONFIG_NVME_RDMA)			+= nvme-rdma.o
>
>   nvme-core-y				:= core.o
>   nvme-core-$(CONFIG_BLK_DEV_NVME_SCSI)	+= scsi.o
> @@ -9,3 +10,5 @@ nvme-core-$(CONFIG_NVM)			+= lightnvm.o
>   nvme-y					+= pci.o
>
>   nvme-fabrics-y				+= fabrics.o
> +
> +nvme-rdma-y				+= rdma.o
> diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
> new file mode 100644
> index 0000000..4edc912
> --- /dev/null
> +++ b/drivers/nvme/host/rdma.c
> @@ -0,0 +1,2009 @@
> +/*
> + * 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/delay.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/string.h>
> +#include <linux/jiffies.h>
> +#include <linux/atomic.h>
> +#include <linux/blk-mq.h>
> +#include <linux/types.h>
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/scatterlist.h>
> +#include <linux/nvme.h>
> +#include <linux/t10-pi.h>
> +#include <asm/unaligned.h>
> +
> +#include <rdma/ib_verbs.h>
> +#include <rdma/rdma_cm.h>
> +#include <rdma/ib_cm.h>
> +#include <linux/nvme-rdma.h>
> +
> +#include "nvme.h"
> +#include "fabrics.h"
> +
> +
> +#define NVME_RDMA_CONNECT_TIMEOUT_MS	1000		/* 1 second */
> +
> +#define NVME_RDMA_MAX_SEGMENT_SIZE	0xffffff	/* 24-bit SGL field */
> +
> +#define NVME_RDMA_MAX_SEGMENTS		256
> +
> +#define NVME_RDMA_MAX_INLINE_SEGMENTS	1
> +
> +#define NVME_RDMA_MAX_PAGES_PER_MR	512
> +
> +#define NVME_RDMA_DEF_RECONNECT_DELAY	20
> +
> +/*
> + * We handle AEN commands ourselves and don't even let the
> + * block layer know about them.
> + */
> +#define NVME_RDMA_NR_AEN_COMMANDS      1
> +#define NVME_RDMA_AQ_BLKMQ_DEPTH       \
> +	(NVMF_AQ_DEPTH - NVME_RDMA_NR_AEN_COMMANDS)
> +
> +struct nvme_rdma_device {
> +	struct ib_device       *dev;
> +	struct ib_pd	       *pd;
> +	struct ib_mr	       *mr;
> +	struct kref		ref;
> +	struct list_head	entry;
> +};
> +
> +struct nvme_rdma_qe {
> +	struct ib_cqe		cqe;
> +	void			*data;
> +	u64			dma;
> +};
> +
> +struct nvme_rdma_queue;
> +struct nvme_rdma_request {
> +	struct ib_mr		*mr;
> +	struct nvme_rdma_qe	sqe;
> +	struct ib_sge		sge[1 + NVME_RDMA_MAX_INLINE_SEGMENTS];
> +	u32			num_sge;
> +	int			nents;
> +	bool			inline_data;
> +	bool			need_inval;
> +	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_CONNECTED = (1 << 0),
> +};
> +
> +struct nvme_rdma_queue {
> +	struct nvme_rdma_qe	*rsp_ring;
> +	u8			sig_count;
> +	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 and written in the hot path */
> +	spinlock_t		lock;
> +
> +	/* read only in the hot path */
> +	struct nvme_rdma_queue	*queues;
> +	u32			queue_count;
> +
> +	/* other member variables */
> +	unsigned short		tl_retry_count;
> +	struct blk_mq_tag_set	tag_set;
> +	struct work_struct	delete_work;
> +	struct work_struct	reset_work;
> +	struct work_struct	err_work;
> +
> +	struct nvme_rdma_qe	async_event_sqe;
> +
> +	int			reconnect_delay;
> +	struct delayed_work	reconnect_work;
> +
> +	struct list_head	list;
> +
> +	struct blk_mq_tag_set	admin_tag_set;
> +	struct nvme_rdma_device	*device;
> +
> +	u64			cap;
> +	u32			max_fr_pages;
> +
> +	union {
> +		struct sockaddr addr;
> +		struct sockaddr_in addr_in;
> +	};
> +
> +	struct nvme_ctrl	ctrl;
> +};
> +
> +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);
> +
> +static struct workqueue_struct *nvme_rdma_wq;
> +
> +/*
> + * 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 int __nvme_rdma_del_ctrl(struct nvme_rdma_ctrl *ctrl);
> +
> +/* 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 %d\n", 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 + NVME_RDMA_MAX_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 int nvme_rdma_reinit_request(void *data, struct request *rq)
> +{
> +	struct nvme_rdma_ctrl *ctrl = data;
> +	struct nvme_rdma_device *dev = ctrl->device;
> +	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
> +	int ret = 0;
> +
> +	if (!req->need_inval)
> +		goto out;
> +
> +	ib_dereg_mr(req->mr);
> +
> +	req->mr = ib_alloc_mr(dev->pd, IB_MR_TYPE_MEM_REG,
> +			ctrl->max_fr_pages);
> +	if (IS_ERR(req->mr)) {
> +		req->mr = NULL;
> +		ret = PTR_ERR(req->mr);
> +	}
> +
> +	req->need_inval = false;
> +
> +out:
> +	return ret;
> +}
> +
> +static void __nvme_rdma_exit_request(struct nvme_rdma_ctrl *ctrl,
> +		struct request *rq, unsigned int queue_idx)
> +{
> +	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
> +	struct nvme_rdma_queue *queue = &ctrl->queues[queue_idx];
> +	struct nvme_rdma_device *dev = queue->device;
> +
> +	if (req->mr)
> +		ib_dereg_mr(req->mr);
> +
> +	nvme_rdma_free_qe(dev->dev, &req->sqe, sizeof(struct nvme_command),
> +			DMA_TO_DEVICE);
> +}
> +
> +static void nvme_rdma_exit_request(void *data, struct request *rq,
> +				unsigned int hctx_idx, unsigned int rq_idx)
> +{
> +	return __nvme_rdma_exit_request(data, rq, hctx_idx + 1);
> +}
> +
> +static void nvme_rdma_exit_admin_request(void *data, struct request *rq,
> +				unsigned int hctx_idx, unsigned int rq_idx)
> +{
> +	return __nvme_rdma_exit_request(data, rq, 0);
> +}
> +
> +static int __nvme_rdma_init_request(struct nvme_rdma_ctrl *ctrl,
> +		struct request *rq, unsigned int queue_idx)
> +{
> +	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
> +	struct nvme_rdma_queue *queue = &ctrl->queues[queue_idx];
> +	struct nvme_rdma_device *dev = queue->device;
> +	struct ib_device *ibdev = dev->dev;
> +	int ret;
> +
> +	BUG_ON(queue_idx >= ctrl->queue_count);
> +
> +	ret = nvme_rdma_alloc_qe(ibdev, &req->sqe, sizeof(struct nvme_command),
> +			DMA_TO_DEVICE);
> +	if (ret)
> +		return ret;
> +
> +	req->mr = ib_alloc_mr(dev->pd, IB_MR_TYPE_MEM_REG,
> +			ctrl->max_fr_pages);
> +	if (IS_ERR(req->mr)) {
> +		ret = PTR_ERR(req->mr);
> +		goto out_free_qe;
> +	}
> +
> +	req->queue = queue;
> +
> +	return 0;
> +
> +out_free_qe:
> +	nvme_rdma_free_qe(dev->dev, &req->sqe, sizeof(struct nvme_command),
> +			DMA_TO_DEVICE);
> +	return -ENOMEM;
> +}
> +
> +static int nvme_rdma_init_request(void *data, struct request *rq,
> +				unsigned int hctx_idx, unsigned int rq_idx,
> +				unsigned int numa_node)
> +{
> +	return __nvme_rdma_init_request(data, rq, hctx_idx + 1);
> +}
> +
> +static int nvme_rdma_init_admin_request(void *data, struct request *rq,
> +				unsigned int hctx_idx, unsigned int rq_idx,
> +				unsigned int numa_node)
> +{
> +	return __nvme_rdma_init_request(data, rq, 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->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);
> +
> +	if (!register_always)
> +		ib_dereg_mr(ndev->mr);
> +	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);
> +	if (IS_ERR(ndev->pd))
> +		goto out_free_dev;
> +
> +	if (!register_always) {
> +		ndev->mr = ib_get_dma_mr(ndev->pd,
> +					    IB_ACCESS_LOCAL_WRITE |
> +					    IB_ACCESS_REMOTE_READ |
> +					    IB_ACCESS_REMOTE_WRITE);
> +		if (IS_ERR(ndev->mr))
> +			goto out_free_pd;
> +	}
> +
> +	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_mr;
> +	}
> +
> +	list_add(&ndev->entry, &device_list);
> +out_unlock:
> +	mutex_unlock(&device_list_mutex);
> +	return ndev;
> +
> +out_free_mr:
> +	if (!register_always)
> +		ib_dereg_mr(ndev->mr);
> +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 = queue->device;
> +	struct ib_device *ibdev = dev->dev;
> +
> +	rdma_destroy_qp(queue->cm_id);
> +	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_create_queue_ib(struct nvme_rdma_queue *queue,
> +		struct nvme_rdma_device *dev)
> +{
> +	struct ib_device *ibdev = dev->dev;
> +	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 = dev;
> +
> +	/*
> +	 * The admin queue is barely used once the controller is live, so don't
> +	 * bother to spread it out.
> +	 */
> +	if (idx == 0)
> +		comp_vector = 0;
> +	else
> +		comp_vector = idx % ibdev->num_comp_vectors;
> +
> +
> +	/* +1 for ib_stop_cq */
> +	queue->ib_cq = ib_alloc_cq(dev->dev, 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;
> +	}
> +
> +	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;
> +	}
> +
> +	return 0;
> +
> +out_destroy_qp:
> +	ib_destroy_qp(queue->qp);
> +out_destroy_ib_cq:
> +	ib_free_cq(queue->ib_cq);
> +out:
> +	return ret;
> +}
> +
> +static int nvme_rdma_init_queue(struct nvme_rdma_ctrl *ctrl,
> +		int idx, size_t queue_size)
> +{
> +	struct nvme_rdma_queue *queue;
> +	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);
> +	}
> +
> +	queue->cm_error = -ETIMEDOUT;
> +	ret = rdma_resolve_addr(queue->cm_id, NULL, &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_resolve_addr wait failed (%d).\n", ret);
> +		goto out_destroy_cm_id;
> +	}
> +
> +	set_bit(NVME_RDMA_Q_CONNECTED, &queue->flags);
> +
> +	return 0;
> +
> +out_destroy_cm_id:
> +	rdma_destroy_id(queue->cm_id);
> +	return ret;
> +}
> +
> +static void nvme_rdma_free_queue(struct nvme_rdma_queue *queue)
> +{
> +	if (!test_and_clear_bit(NVME_RDMA_Q_CONNECTED, &queue->flags))
> +		return;
> +
> +	rdma_disconnect(queue->cm_id);
> +	ib_drain_qp(queue->qp);
> +	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->queue_count; i++)
> +		nvme_rdma_free_queue(&ctrl->queues[i]);
> +}
> +
> +static int nvme_rdma_connect_io_queues(struct nvme_rdma_ctrl *ctrl)
> +{
> +	int i, ret = 0;
> +
> +	for (i = 1; i < ctrl->queue_count; i++) {
> +		ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
> +		if (ret)
> +			break;
> +	}
> +
> +	return ret;
> +}
> +
> +static int nvme_rdma_init_io_queues(struct nvme_rdma_ctrl *ctrl)
> +{
> +	int i, ret;
> +
> +	for (i = 1; i < ctrl->queue_count; i++) {
> +		ret = nvme_rdma_init_queue(ctrl, i, ctrl->ctrl.sqsize);
> +		if (ret) {
> +			dev_info(ctrl->ctrl.device,
> +				"failed to initialize i/o queue: %d\n", ret);
> +			goto out_free_queues;
> +		}
> +	}
> +
> +	return 0;
> +
> +out_free_queues:
> +	for (; i >= 1; i--)
> +		nvme_rdma_free_queue(&ctrl->queues[i]);
> +
> +	return ret;
> +}
> +
> +static void nvme_rdma_destroy_admin_queue(struct nvme_rdma_ctrl *ctrl)
> +{
> +	nvme_rdma_free_qe(ctrl->queues[0].device->dev, &ctrl->async_event_sqe,
> +			sizeof(struct nvme_command), DMA_TO_DEVICE);
> +	nvme_rdma_free_queue(&ctrl->queues[0]);
> +	blk_cleanup_queue(ctrl->ctrl.admin_q);
> +	blk_mq_free_tag_set(&ctrl->admin_tag_set);
> +	nvme_rdma_dev_put(ctrl->device);
> +}
> +
> +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);
> +
> +	if (ctrl->ctrl.tagset) {
> +		blk_cleanup_queue(ctrl->ctrl.connect_q);
> +		blk_mq_free_tag_set(&ctrl->tag_set);
> +		nvme_rdma_dev_put(ctrl->device);
> +	}
> +	kfree(ctrl->queues);
> +	nvmf_free_options(nctrl->opts);
> +free_ctrl:
> +	kfree(ctrl);
> +}
> +
> +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);
> +	bool changed;
> +	int ret;
> +
> +	if (ctrl->queue_count > 1) {
> +		nvme_rdma_free_io_queues(ctrl);
> +
> +		ret = blk_mq_reinit_tagset(&ctrl->tag_set);
> +		if (ret)
> +			goto requeue;
> +	}
> +
> +	nvme_rdma_free_queue(&ctrl->queues[0]);
> +
> +	ret = blk_mq_reinit_tagset(&ctrl->admin_tag_set);
> +	if (ret)
> +		goto requeue;
> +
> +	ret = nvme_rdma_init_queue(ctrl, 0, NVMF_AQ_DEPTH);
> +	if (ret)
> +		goto requeue;
> +
> +	blk_mq_start_stopped_hw_queues(ctrl->ctrl.admin_q, true);
> +
> +	ret = nvmf_connect_admin_queue(&ctrl->ctrl);
> +	if (ret)
> +		goto stop_admin_q;
> +
> +	ret = nvme_enable_ctrl(&ctrl->ctrl, ctrl->cap);
> +	if (ret)
> +		goto stop_admin_q;
> +
> +	nvme_start_keep_alive(&ctrl->ctrl);
> +
> +	if (ctrl->queue_count > 1) {
> +		ret = nvme_rdma_init_io_queues(ctrl);
> +		if (ret)
> +			goto stop_admin_q;
> +
> +		ret = nvme_rdma_connect_io_queues(ctrl);
> +		if (ret)
> +			goto stop_admin_q;
> +	}
> +
> +	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
> +	WARN_ON_ONCE(!changed);
> +
> +	if (ctrl->queue_count > 1)
> +		nvme_start_queues(&ctrl->ctrl);
> +
> +	dev_info(ctrl->ctrl.device, "Successfully reconnected\n");
> +
> +	return;
> +
> +stop_admin_q:
> +	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
> +requeue:
> +	/* Make sure we are not resetting/deleting */
> +	if (ctrl->ctrl.state == NVME_CTRL_RECONNECTING) {
> +		dev_info(ctrl->ctrl.device,
> +			"Failed reconnect attempt, requeueing...\n");
> +		queue_delayed_work(nvme_rdma_wq, &ctrl->reconnect_work,
> +					ctrl->reconnect_delay * HZ);
> +	}
> +}
> +
> +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);
> +	if (ctrl->queue_count > 1)
> +		nvme_stop_queues(&ctrl->ctrl);
> +	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
> +
> +	/* We must take care of fastfail/requeue all our inflight requests */
> +	if (ctrl->queue_count > 1)
> +		blk_mq_tagset_busy_iter(&ctrl->tag_set,
> +					nvme_cancel_request, &ctrl->ctrl);
> +	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
> +				nvme_cancel_request, &ctrl->ctrl);
> +
> +	dev_info(ctrl->ctrl.device, "reconnecting in %d seconds\n",
> +		ctrl->reconnect_delay);
> +
> +	queue_delayed_work(nvme_rdma_wq, &ctrl->reconnect_work,
> +				ctrl->reconnect_delay * HZ);
> +}
> +
> +static void nvme_rdma_error_recovery(struct nvme_rdma_ctrl *ctrl)
> +{
> +	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RECONNECTING))
> +		return;
> +
> +	queue_work(nvme_rdma_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)
> +{
> +	if (unlikely(wc->status != IB_WC_SUCCESS))
> +		nvme_rdma_wr_error(cq, wc, "LOCAL_INV");
> +}
> +
> +static int nvme_rdma_inv_rkey(struct nvme_rdma_queue *queue,
> +		struct nvme_rdma_request *req)
> +{
> +	struct ib_send_wr *bad_wr;
> +	struct ib_send_wr wr = {
> +		.opcode		    = IB_WR_LOCAL_INV,
> +		.next		    = NULL,
> +		.num_sge	    = 0,
> +		.send_flags	    = 0,
> +		.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, &bad_wr);
> +}
> +
> +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_ctrl *ctrl = queue->ctrl;
> +	struct nvme_rdma_device *dev = queue->device;
> +	struct ib_device *ibdev = dev->dev;
> +	int res;
> +
> +	if (!blk_rq_bytes(rq))
> +		return;
> +
> +	if (req->need_inval) {
> +		res = nvme_rdma_inv_rkey(queue, req);
> +		if (res < 0) {
> +			dev_err(ctrl->ctrl.device,
> +				"Queueing INV WR for rkey %#x failed (%d)\n",
> +				req->mr->rkey, res);
> +			nvme_rdma_error_recovery(queue->ctrl);
> +		}
> +	}
> +
> +	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)
> +{
> +	struct nvme_sgl_desc *sg = &c->common.dptr.sgl;
> +
> +	req->sge[1].addr = sg_dma_address(req->sg_table.sgl);
> +	req->sge[1].length = sg_dma_len(req->sg_table.sgl);
> +	req->sge[1].lkey = queue->device->pd->local_dma_lkey;
> +
> +	sg->addr = cpu_to_le64(queue->ctrl->ctrl.icdoff);
> +	sg->length = cpu_to_le32(sg_dma_len(req->sg_table.sgl));
> +	sg->type = (NVME_SGL_FMT_DATA_DESC << 4) | NVME_SGL_FMT_OFFSET;
> +
> +	req->inline_data = true;
> +	req->num_sge++;
> +	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->mr->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;
> +
> +	nr = ib_map_mr_sg(req->mr, req->sg_table.sgl, count, NULL, PAGE_SIZE);
> +	if (nr < count) {
> +		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;
> +
> +	req->need_inval = true;
> +
> +	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, unsigned int map_len,
> +		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 nents, count;
> +	int ret;
> +
> +	req->num_sge = 1;
> +	req->inline_data = false;
> +	req->need_inval = false;
> +
> +	c->common.flags |= NVME_CMD_SGL_METABUF;
> +
> +	if (!blk_rq_bytes(rq))
> +		return nvme_rdma_set_sg_null(c);
> +
> +	req->sg_table.sgl = req->first_sgl;
> +	ret = sg_alloc_table_chained(&req->sg_table, rq->nr_phys_segments,
> +				req->sg_table.sgl);
> +	if (ret)
> +		return -ENOMEM;
> +
> +	nents = blk_rq_map_sg(rq->q, rq, req->sg_table.sgl);
> +	BUG_ON(nents > rq->nr_phys_segments);
> +	req->nents = nents;
> +
> +	count = ib_dma_map_sg(ibdev, req->sg_table.sgl, nents,
> +		    rq_data_dir(rq) == WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
> +	if (unlikely(count <= 0)) {
> +		sg_free_table_chained(&req->sg_table, true);
> +		return -EIO;
> +	}
> +
> +	if (count == 1) {
> +		if (rq_data_dir(rq) == WRITE &&
> +		    map_len <= nvme_rdma_inline_data_size(queue) &&
> +		    nvme_rdma_queue_idx(queue))
> +			return nvme_rdma_map_sg_inline(queue, req, c);
> +
> +		if (!register_always)
> +			return nvme_rdma_map_sg_single(queue, req, c);
> +	}
> +
> +	return nvme_rdma_map_sg_fr(queue, req, c, count);
> +}
> +
> +static void nvme_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
> +{
> +	if (unlikely(wc->status != IB_WC_SUCCESS))
> +		nvme_rdma_wr_error(cq, wc, "SEND");
> +}
> +
> +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, bool flush)
> +{
> +	struct ib_send_wr wr, *bad_wr;
> +	int ret;
> +
> +	sge->addr   = qe->dma;
> +	sge->length = sizeof(struct nvme_command),
> +	sge->lkey   = queue->device->pd->local_dma_lkey;
> +
> +	qe->cqe.done = nvme_rdma_send_done;
> +
> +	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 = 0;
> +
> +	/*
> +	 * Unsignalled send completions are another giant desaster in the
> +	 * IB Verbs spec:  If we don't regularly post signalled sends
> +	 * the send queue will fill up and only a QP reset will rescue us.
> +	 * Would have been way to obvious to handle this in hardware or
> +	 * at least the RDMA stack..
> +	 *
> +	 * This messy and racy code sniplet is copy and pasted from the iSER
> +	 * initiator, and the magic '32' comes from there as well.
> +	 *
> +	 * Always signal the flushes. The magic request used for the flush
> +	 * sequencer is not allocated in our driver's tagset and it's
> +	 * triggered to be freed by blk_cleanup_queue(). So we need to
> +	 * always mark it as signaled to ensure that the "wr_cqe", which is
> +	 * embeded in request's payload, is not freed when __ib_process_cq()
> +	 * calls wr_cqe->done().
> +	 */
> +	if ((++queue->sig_count % 32) == 0 || flush)
> +		wr.send_flags |= IB_SEND_SIGNALED;
> +
> +	if (first)
> +		first->next = ≀
> +	else
> +		first = ≀
> +
> +	ret = ib_post_send(queue->qp, first, &bad_wr);
> +	if (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, *bad_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, &bad_wr);
> +	if (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_submit_async_event(struct nvme_ctrl *arg, int aer_idx)
> +{
> +	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;
> +
> +	if (WARN_ON_ONCE(aer_idx != 0))
> +		return;
> +
> +	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_RDMA_AQ_BLKMQ_DEPTH;
> +	nvme_rdma_set_sg_null(cmd);
> +
> +	ib_dma_sync_single_for_device(dev, sqe->dma, sizeof(*cmd),
> +			DMA_TO_DEVICE);
> +
> +	ret = nvme_rdma_post_send(queue, sqe, &sge, 1, NULL, false);
> +	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)
> +{
> +	u16 status = le16_to_cpu(cqe->status);
> +	struct request *rq;
> +	struct nvme_rdma_request *req;
> +	int ret = 0;
> +
> +	status >>= 1;
> +
> +	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);
> +
> +	if (rq->cmd_type == REQ_TYPE_DRV_PRIV && rq->special)
> +		memcpy(rq->special, cqe, sizeof(*cqe));
> +
> +	if (rq->tag == tag)
> +		ret = 1;
> +
> +	if ((wc->wc_flags & IB_WC_WITH_INVALIDATE) &&
> +	    wc->ex.invalidate_rkey == req->mr->rkey)
> +		req->need_inval = false;
> +
> +	blk_mq_complete_request(rq, status);
> +
> +	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_RDMA_AQ_BLKMQ_DEPTH))
> +		nvme_complete_async_event(&queue->ctrl->ctrl, cqe);
> +	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)
> +{
> +	if (ev->status == IB_CM_REJ_CONSUMER_DEFINED) {
> +		struct nvme_rdma_cm_rej *rej =
> +			(struct nvme_rdma_cm_rej *)ev->param.conn.private_data;
> +
> +		dev_err(queue->ctrl->ctrl.device,
> +			"Connect rejected, status %d.", le16_to_cpu(rej->sts));
> +		/* XXX: Think of something clever to do here... */
> +	} else {
> +		dev_err(queue->ctrl->ctrl.device,
> +			"Connect rejected, no private data.\n");
> +	}
> +
> +	return -ECONNRESET;
> +}
> +
> +static int nvme_rdma_addr_resolved(struct nvme_rdma_queue *queue)
> +{
> +	struct nvme_rdma_device *dev;
> +	int ret;
> +
> +	dev = nvme_rdma_find_get_device(queue->cm_id);
> +	if (!dev) {
> +		dev_err(queue->cm_id->device->dma_device,
> +			"no client data found!\n");
> +		return -ECONNREFUSED;
> +	}
> +
> +	ret = nvme_rdma_create_queue_ib(queue, dev);
> +	if (ret) {
> +		nvme_rdma_dev_put(dev);
> +		goto out;
> +	}
> +
> +	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);
> +out:
> +	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;
> +	/* rdma_cm will clamp down to max QP retry count (7) */
> +	param.retry_count = ctrl->tl_retry_count;
> +	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));
> +	priv.hrqsize = cpu_to_le16(queue->queue_size);
> +	priv.hsqsize = cpu_to_le16(queue->queue_size);
> +
> +	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;
> +}
> +
> +/**
> + * nvme_rdma_device_unplug() - Handle RDMA device unplug
> + * @queue:      Queue that owns the cm_id that caught the event
> + *
> + * DEVICE_REMOVAL event notifies us that the RDMA device is about
> + * to unplug so we should take care of destroying our RDMA resources.
> + * This event will be generated for each allocated cm_id.
> + *
> + * In our case, the RDMA resources are managed per controller and not
> + * only per queue. So the way we handle this is we trigger an implicit
> + * controller deletion upon the first DEVICE_REMOVAL event we see, and
> + * hold the event inflight until the controller deletion is completed.
> + *
> + * One exception that we need to handle is the destruction of the cm_id
> + * that caught the event. Since we hold the callout until the controller
> + * deletion is completed, we'll deadlock if the controller deletion will
> + * call rdma_destroy_id on this queue's cm_id. Thus, we claim ownership
> + * of destroying this queue before-hand, destroy the queue resources
> + * after the controller deletion completed with the exception of destroying
> + * the cm_id implicitely by returning a non-zero rc to the callout.
> + */
> +static int nvme_rdma_device_unplug(struct nvme_rdma_queue *queue)
> +{
> +	struct nvme_rdma_ctrl *ctrl = queue->ctrl;
> +	int ret, ctrl_deleted = 0;
> +
> +	/* First disable the queue so ctrl delete won't free it */
> +	if (!test_and_clear_bit(NVME_RDMA_Q_CONNECTED, &queue->flags))
> +		goto out;
> +
> +	/* delete the controller */
> +	ret = __nvme_rdma_del_ctrl(ctrl);
> +	if (!ret) {
> +		dev_warn(ctrl->ctrl.device,
> +			"Got rdma device removal event, deleting ctrl\n");
> +		flush_work(&ctrl->delete_work);
> +
> +		/* Return non-zero so the cm_id will destroy implicitly */
> +		ctrl_deleted = 1;
> +
> +		/* Free this queue ourselves */
> +		rdma_disconnect(queue->cm_id);
> +		ib_drain_qp(queue->qp);
> +		nvme_rdma_destroy_queue_ib(queue);
> +	}
> +
> +out:
> +	return ctrl_deleted;
> +}
> +
> +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_ADDR_ERROR:
> +	case RDMA_CM_EVENT_ROUTE_ERROR:
> +	case RDMA_CM_EVENT_CONNECT_ERROR:
> +	case RDMA_CM_EVENT_UNREACHABLE:
> +		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:
> +		/* return 1 means impliciy CM ID destroy */
> +		return nvme_rdma_device_unplug(queue);
> +	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);
> +
> +	/* queue error recovery */
> +	nvme_rdma_error_recovery(req->queue->ctrl);
> +
> +	/* fail with DNR on cmd timeout */
> +	rq->errors = NVME_SC_ABORT_REQ | NVME_SC_DNR;
> +
> +	return BLK_EH_HANDLED;
> +}
> +
> +static int 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;
> +	bool flush = false;
> +	struct ib_device *dev;
> +	unsigned int map_len;
> +	int ret;
> +
> +	WARN_ON_ONCE(rq->tag < 0);
> +
> +	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;
> +
> +	c->common.command_id = rq->tag;
> +	blk_mq_start_request(rq);
> +
> +	map_len = nvme_map_len(rq);
> +	ret = nvme_rdma_map_data(queue, rq, map_len, c);
> +	if (ret < 0) {
> +		dev_err(queue->ctrl->ctrl.device,
> +			     "Failed to map data (%d)\n", ret);
> +		nvme_cleanup_cmd(rq);
> +		goto err;
> +	}
> +
> +	ib_dma_sync_single_for_device(dev, sqe->dma,
> +			sizeof(struct nvme_command), DMA_TO_DEVICE);
> +
> +	if (rq->cmd_type == REQ_TYPE_FS && (rq->cmd_flags & REQ_FLUSH))
> +		flush = true;
> +	ret = nvme_rdma_post_send(queue, sqe, req->sge, req->num_sge,
> +			req->need_inval ? &req->reg_wr.wr : NULL, flush);
> +	if (ret) {
> +		nvme_rdma_unmap_data(queue, rq);
> +		goto err;
> +	}
> +
> +	return BLK_MQ_RQ_QUEUE_OK;
> +err:
> +	return (ret == -ENOMEM || ret == -EAGAIN) ?
> +		BLK_MQ_RQ_QUEUE_BUSY : BLK_MQ_RQ_QUEUE_ERROR;
> +}
> +
> +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;
> +
> +	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
> +	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);
> +	struct nvme_rdma_queue *queue = req->queue;
> +	int error = 0;
> +
> +	nvme_rdma_unmap_data(queue, rq);
> +
> +	if (unlikely(rq->errors)) {
> +		if (nvme_req_needs_retry(rq, rq->errors)) {
> +			nvme_requeue_req(rq);
> +			return;
> +		}
> +
> +		if (rq->cmd_type == REQ_TYPE_DRV_PRIV)
> +			error = rq->errors;
> +		else
> +			error = nvme_error_status(rq->errors);
> +	}
> +
> +	blk_mq_end_request(rq, error);
> +}
> +
> +static struct blk_mq_ops nvme_rdma_mq_ops = {
> +	.queue_rq	= nvme_rdma_queue_rq,
> +	.complete	= nvme_rdma_complete_rq,
> +	.map_queue	= blk_mq_map_queue,
> +	.init_request	= nvme_rdma_init_request,
> +	.exit_request	= nvme_rdma_exit_request,
> +	.reinit_request	= nvme_rdma_reinit_request,
> +	.init_hctx	= nvme_rdma_init_hctx,
> +	.poll		= nvme_rdma_poll,
> +	.timeout	= nvme_rdma_timeout,
> +};
> +
> +static struct blk_mq_ops nvme_rdma_admin_mq_ops = {
> +	.queue_rq	= nvme_rdma_queue_rq,
> +	.complete	= nvme_rdma_complete_rq,
> +	.map_queue	= blk_mq_map_queue,
> +	.init_request	= nvme_rdma_init_admin_request,
> +	.exit_request	= nvme_rdma_exit_admin_request,
> +	.reinit_request	= nvme_rdma_reinit_request,
> +	.init_hctx	= nvme_rdma_init_admin_hctx,
> +	.timeout	= nvme_rdma_timeout,
> +};
> +
> +static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl)
> +{
> +	int error;
> +
> +	error = nvme_rdma_init_queue(ctrl, 0, NVMF_AQ_DEPTH);
> +	if (error)
> +		return error;
> +
> +	ctrl->device = ctrl->queues[0].device;
> +
> +	/*
> +	 * 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.
> +	 */
> +	error = -EINVAL;
> +	if (!nvme_rdma_dev_get(ctrl->device))
> +		goto out_free_queue;
> +
> +	ctrl->max_fr_pages = min_t(u32, NVME_RDMA_MAX_SEGMENTS,
> +		ctrl->device->dev->attrs.max_fast_reg_page_list_len);
> +
> +	memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
> +	ctrl->admin_tag_set.ops = &nvme_rdma_admin_mq_ops;
> +	ctrl->admin_tag_set.queue_depth = NVME_RDMA_AQ_BLKMQ_DEPTH;
> +	ctrl->admin_tag_set.reserved_tags = 2; /* connect + keep-alive */
> +	ctrl->admin_tag_set.numa_node = NUMA_NO_NODE;
> +	ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_rdma_request) +
> +		SG_CHUNK_SIZE * sizeof(struct scatterlist);
> +	ctrl->admin_tag_set.driver_data = ctrl;
> +	ctrl->admin_tag_set.nr_hw_queues = 1;
> +	ctrl->admin_tag_set.timeout = ADMIN_TIMEOUT;
> +
> +	error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
> +	if (error)
> +		goto out_put_dev;
> +
> +	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 = nvmf_connect_admin_queue(&ctrl->ctrl);
> +	if (error)
> +		goto out_cleanup_queue;
> +
> +	error = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->cap);
> +	if (error) {
> +		dev_err(ctrl->ctrl.device,
> +			"prop_get NVME_REG_CAP failed\n");
> +		goto out_cleanup_queue;
> +	}
> +
> +	ctrl->ctrl.sqsize =
> +		min_t(int, NVME_CAP_MQES(ctrl->cap) + 1, ctrl->ctrl.sqsize);
> +
> +	error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->cap);
> +	if (error)
> +		goto out_cleanup_queue;
> +
> +	ctrl->ctrl.max_hw_sectors =
> +		(ctrl->max_fr_pages - 1) << (PAGE_SHIFT - 9);
> +
> +	error = nvme_init_identify(&ctrl->ctrl);
> +	if (error)
> +		goto out_cleanup_queue;
> +
> +	nvme_start_keep_alive(&ctrl->ctrl);
> +
> +	error = nvme_rdma_alloc_qe(ctrl->queues[0].device->dev,
> +			&ctrl->async_event_sqe, sizeof(struct nvme_command),
> +			DMA_TO_DEVICE);
> +	if (error)
> +		goto out_cleanup_queue;
> +
> +	return 0;
> +
> +out_cleanup_queue:
> +	blk_cleanup_queue(ctrl->ctrl.admin_q);
> +out_free_tagset:
> +	blk_mq_free_tag_set(&ctrl->admin_tag_set);
> +out_put_dev:
> +	nvme_rdma_dev_put(ctrl->device);
> +out_free_queue:
> +	nvme_rdma_free_queue(&ctrl->queues[0]);
> +	return error;
> +}
> +
> +static void nvme_rdma_shutdown_ctrl(struct nvme_rdma_ctrl *ctrl)
> +{
> +	nvme_stop_keep_alive(&ctrl->ctrl);
> +	cancel_work_sync(&ctrl->err_work);
> +	cancel_delayed_work_sync(&ctrl->reconnect_work);
> +
> +	if (ctrl->queue_count > 1) {
> +		nvme_stop_queues(&ctrl->ctrl);
> +		blk_mq_tagset_busy_iter(&ctrl->tag_set,
> +					nvme_cancel_request, &ctrl->ctrl);
> +		nvme_rdma_free_io_queues(ctrl);
> +	}
> +
> +	if (ctrl->ctrl.state == NVME_CTRL_LIVE)
> +		nvme_shutdown_ctrl(&ctrl->ctrl);
> +
> +	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
> +	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
> +				nvme_cancel_request, &ctrl->ctrl);
> +	nvme_rdma_destroy_admin_queue(ctrl);
> +}
> +
> +static void nvme_rdma_del_ctrl_work(struct work_struct *work)
> +{
> +	struct nvme_rdma_ctrl *ctrl = container_of(work,
> +				struct nvme_rdma_ctrl, delete_work);
> +
> +	nvme_remove_namespaces(&ctrl->ctrl);
> +	nvme_rdma_shutdown_ctrl(ctrl);
> +	nvme_uninit_ctrl(&ctrl->ctrl);
> +	nvme_put_ctrl(&ctrl->ctrl);
> +}
> +
> +static int __nvme_rdma_del_ctrl(struct nvme_rdma_ctrl *ctrl)
> +{
> +	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING))
> +		return -EBUSY;
> +
> +	if (!queue_work(nvme_rdma_wq, &ctrl->delete_work))
> +		return -EBUSY;
> +
> +	return 0;
> +}
> +
> +static int nvme_rdma_del_ctrl(struct nvme_ctrl *nctrl)
> +{
> +	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
> +	int ret;
> +
> +	ret = __nvme_rdma_del_ctrl(ctrl);
> +	if (ret)
> +		return ret;
> +
> +	flush_work(&ctrl->delete_work);
> +
> +	return 0;
> +}
> +
> +static void nvme_rdma_remove_ctrl_work(struct work_struct *work)
> +{
> +	struct nvme_rdma_ctrl *ctrl = container_of(work,
> +				struct nvme_rdma_ctrl, delete_work);
> +
> +	nvme_remove_namespaces(&ctrl->ctrl);
> +	nvme_uninit_ctrl(&ctrl->ctrl);
> +	nvme_put_ctrl(&ctrl->ctrl);
> +}
> +
> +static void nvme_rdma_reset_ctrl_work(struct work_struct *work)
> +{
> +	struct nvme_rdma_ctrl *ctrl = container_of(work,
> +					struct nvme_rdma_ctrl, reset_work);
> +	int ret;
> +	bool changed;
> +
> +	nvme_rdma_shutdown_ctrl(ctrl);
> +
> +	ret = nvme_rdma_configure_admin_queue(ctrl);
> +	if (ret) {
> +		/* ctrl is already shutdown, just remove the ctrl */
> +		INIT_WORK(&ctrl->delete_work, nvme_rdma_remove_ctrl_work);
> +		goto del_dead_ctrl;
> +	}
> +
> +	if (ctrl->queue_count > 1) {
> +		ret = blk_mq_reinit_tagset(&ctrl->tag_set);
> +		if (ret)
> +			goto del_dead_ctrl;
> +
> +		ret = nvme_rdma_init_io_queues(ctrl);
> +		if (ret)
> +			goto del_dead_ctrl;
> +
> +		ret = nvme_rdma_connect_io_queues(ctrl);
> +		if (ret)
> +			goto del_dead_ctrl;
> +	}
> +
> +	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
> +	WARN_ON_ONCE(!changed);
> +
> +	if (ctrl->queue_count > 1) {
> +		nvme_start_queues(&ctrl->ctrl);
> +		nvme_queue_scan(&ctrl->ctrl);
> +	}
> +
> +	return;
> +
> +del_dead_ctrl:
> +	/* Deleting this dead controller... */
> +	dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
> +	WARN_ON(!queue_work(nvme_rdma_wq, &ctrl->delete_work));
> +}
> +
> +static int nvme_rdma_reset_ctrl(struct nvme_ctrl *nctrl)
> +{
> +	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
> +
> +	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING))
> +		return -EBUSY;
> +
> +	if (!queue_work(nvme_rdma_wq, &ctrl->reset_work))
> +		return -EBUSY;
> +
> +	flush_work(&ctrl->reset_work);
> +
> +	return 0;
> +}
> +
> +static const struct nvme_ctrl_ops nvme_rdma_ctrl_ops = {
> +	.name			= "rdma",
> +	.module			= THIS_MODULE,
> +	.is_fabrics		= true,
> +	.reg_read32		= nvmf_reg_read32,
> +	.reg_read64		= nvmf_reg_read64,
> +	.reg_write32		= nvmf_reg_write32,
> +	.reset_ctrl		= nvme_rdma_reset_ctrl,
> +	.free_ctrl		= nvme_rdma_free_ctrl,
> +	.submit_async_event	= nvme_rdma_submit_async_event,
> +	.delete_ctrl		= nvme_rdma_del_ctrl,
> +	.get_subsysnqn		= nvmf_get_subsysnqn,
> +	.get_address		= nvmf_get_address,
> +};
> +
> +static int nvme_rdma_create_io_queues(struct nvme_rdma_ctrl *ctrl)
> +{
> +	struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
> +	int ret;
> +
> +	ret = nvme_set_queue_count(&ctrl->ctrl, &opts->nr_io_queues);
> +	if (ret)
> +		return ret;
> +
> +	ctrl->queue_count = opts->nr_io_queues + 1;
> +	if (ctrl->queue_count < 2)
> +		return 0;
> +
> +	dev_info(ctrl->ctrl.device,
> +		"creating %d I/O queues.\n", opts->nr_io_queues);
> +
> +	ret = nvme_rdma_init_io_queues(ctrl);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * 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 = -EINVAL;
> +	if (!nvme_rdma_dev_get(ctrl->device))
> +		goto out_free_io_queues;
> +
> +	memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
> +	ctrl->tag_set.ops = &nvme_rdma_mq_ops;
> +	ctrl->tag_set.queue_depth = ctrl->ctrl.sqsize;
> +	ctrl->tag_set.reserved_tags = 1; /* fabric connect */
> +	ctrl->tag_set.numa_node = NUMA_NO_NODE;
> +	ctrl->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
> +	ctrl->tag_set.cmd_size = sizeof(struct nvme_rdma_request) +
> +		SG_CHUNK_SIZE * sizeof(struct scatterlist);
> +	ctrl->tag_set.driver_data = ctrl;
> +	ctrl->tag_set.nr_hw_queues = ctrl->queue_count - 1;
> +	ctrl->tag_set.timeout = NVME_IO_TIMEOUT;
> +
> +	ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
> +	if (ret)
> +		goto out_put_dev;
> +	ctrl->ctrl.tagset = &ctrl->tag_set;
> +
> +	ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
> +	if (IS_ERR(ctrl->ctrl.connect_q)) {
> +		ret = PTR_ERR(ctrl->ctrl.connect_q);
> +		goto out_free_tag_set;
> +	}
> +
> +	ret = nvme_rdma_connect_io_queues(ctrl);
> +	if (ret)
> +		goto out_cleanup_connect_q;
> +
> +	return 0;
> +
> +out_cleanup_connect_q:
> +	nvme_stop_keep_alive(&ctrl->ctrl);
> +	blk_cleanup_queue(ctrl->ctrl.connect_q);
> +out_free_tag_set:
> +	blk_mq_free_tag_set(&ctrl->tag_set);
> +out_put_dev:
> +	nvme_rdma_dev_put(ctrl->device);
> +out_free_io_queues:
> +	nvme_rdma_free_io_queues(ctrl);
> +	return ret;
> +}
> +
> +static int nvme_rdma_parse_ipaddr(struct sockaddr_in *in_addr, char *p)
> +{
> +	u8 *addr = (u8 *)&in_addr->sin_addr.s_addr;
> +	size_t buflen = strlen(p);
> +
> +	/* XXX: handle IPv6 addresses */
> +
> +	if (buflen > INET_ADDRSTRLEN)
> +		return -EINVAL;
> +	if (in4_pton(p, buflen, addr, '\0', NULL) == 0)
> +		return -EINVAL;
> +	in_addr->sin_family = AF_INET;
> +	return 0;
> +}
> +
> +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);
> +
> +	ret = nvme_rdma_parse_ipaddr(&ctrl->addr_in, opts->traddr);
> +	if (ret) {
> +		pr_err("malformed IP address passed: %s\n", opts->traddr);
> +		goto out_free_ctrl;
> +	}
> +
> +	if (opts->mask & NVMF_OPT_TRSVCID) {
> +		u16 port;
> +
> +		ret = kstrtou16(opts->trsvcid, 0, &port);
> +		if (ret)
> +			goto out_free_ctrl;
> +
> +		ctrl->addr_in.sin_port = cpu_to_be16(port);
> +	} else {
> +		ctrl->addr_in.sin_port = cpu_to_be16(NVME_RDMA_IP_PORT);
> +	}
> +
> +	ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_rdma_ctrl_ops,
> +				0 /* no quirks, we're perfect! */);
> +	if (ret)
> +		goto out_free_ctrl;
> +
> +	ctrl->reconnect_delay = opts->reconnect_delay;
> +	INIT_DELAYED_WORK(&ctrl->reconnect_work,
> +			nvme_rdma_reconnect_ctrl_work);
> +	INIT_WORK(&ctrl->err_work, nvme_rdma_error_recovery_work);
> +	INIT_WORK(&ctrl->delete_work, nvme_rdma_del_ctrl_work);
> +	INIT_WORK(&ctrl->reset_work, nvme_rdma_reset_ctrl_work);
> +	spin_lock_init(&ctrl->lock);
> +
> +	ctrl->queue_count = opts->nr_io_queues + 1; /* +1 for admin queue */
> +	ctrl->ctrl.sqsize = opts->queue_size;
> +	ctrl->tl_retry_count = opts->tl_retry_count;
> +	ctrl->ctrl.kato = opts->kato;
> +
> +	ret = -ENOMEM;
> +	ctrl->queues = kcalloc(ctrl->queue_count, sizeof(*ctrl->queues),
> +				GFP_KERNEL);
> +	if (!ctrl->queues)
> +		goto out_uninit_ctrl;
> +
> +	ret = nvme_rdma_configure_admin_queue(ctrl);
> +	if (ret)
> +		goto out_kfree_queues;
> +
> +	/* sanity check icdoff */
> +	if (ctrl->ctrl.icdoff) {
> +		dev_err(ctrl->ctrl.device, "icdoff is not supported!\n");
> +		goto out_remove_admin_queue;
> +	}
> +
> +	/* sanity check keyed sgls */
> +	if (!(ctrl->ctrl.sgls & (1 << 20))) {
> +		dev_err(ctrl->ctrl.device, "Mandatory keyed sgls are not support\n");
> +		goto out_remove_admin_queue;
> +	}
> +
> +	if (opts->queue_size > ctrl->ctrl.maxcmd) {
> +		/* warn if maxcmd is lower than queue_size */
> +		dev_warn(ctrl->ctrl.device,
> +			"queue_size %zu > ctrl maxcmd %u, clamping down\n",
> +			opts->queue_size, ctrl->ctrl.maxcmd);
> +		opts->queue_size = ctrl->ctrl.maxcmd;
> +	}
> +
> +	if (opts->nr_io_queues) {
> +		ret = nvme_rdma_create_io_queues(ctrl);
> +		if (ret)
> +			goto out_remove_admin_queue;
> +	}
> +
> +	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
> +	WARN_ON_ONCE(!changed);
> +
> +	dev_info(ctrl->ctrl.device, "new ctrl: NQN \"%s\", addr %pISp\n",
> +		ctrl->ctrl.opts->subsysnqn, &ctrl->addr);
> +
> +	kref_get(&ctrl->ctrl.kref);
> +
> +	mutex_lock(&nvme_rdma_ctrl_mutex);
> +	list_add_tail(&ctrl->list, &nvme_rdma_ctrl_list);
> +	mutex_unlock(&nvme_rdma_ctrl_mutex);
> +
> +	if (opts->nr_io_queues) {
> +		nvme_queue_scan(&ctrl->ctrl);
> +		nvme_queue_async_events(&ctrl->ctrl);
> +	}
> +
> +	return &ctrl->ctrl;
> +
> +out_remove_admin_queue:
> +	nvme_rdma_destroy_admin_queue(ctrl);
> +out_kfree_queues:
> +	kfree(ctrl->queues);
> +out_uninit_ctrl:
> +	nvme_uninit_ctrl(&ctrl->ctrl);
> +	nvme_put_ctrl(&ctrl->ctrl);
> +	if (ret > 0)
> +		ret = -EIO;
> +	return ERR_PTR(ret);
> +out_free_ctrl:
> +	kfree(ctrl);
> +	return ERR_PTR(ret);
> +}
> +
> +static struct nvmf_transport_ops nvme_rdma_transport = {
> +	.name		= "rdma",
> +	.required_opts	= NVMF_OPT_TRADDR,
> +	.allowed_opts	= NVMF_OPT_TRSVCID | NVMF_OPT_TL_RETRY_COUNT |
> +			  NVMF_OPT_RECONNECT_DELAY,
> +	.create_ctrl	= nvme_rdma_create_ctrl,
> +};
> +
> +static int __init nvme_rdma_init_module(void)
> +{
> +	nvme_rdma_wq = create_workqueue("nvme_rdma_wq");
> +	if (!nvme_rdma_wq)
> +		return -ENOMEM;
> +
> +	nvmf_register_transport(&nvme_rdma_transport);
> +	return 0;
> +}
> +
> +static void __exit nvme_rdma_cleanup_module(void)
> +{
> +	struct nvme_rdma_ctrl *ctrl;
> +
> +	nvmf_unregister_transport(&nvme_rdma_transport);
> +
> +	mutex_lock(&nvme_rdma_ctrl_mutex);
> +	list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list)
> +		__nvme_rdma_del_ctrl(ctrl);
> +	mutex_unlock(&nvme_rdma_ctrl_mutex);
> +
> +	destroy_workqueue(nvme_rdma_wq);
> +}
> +
> +module_init(nvme_rdma_init_module);
> +module_exit(nvme_rdma_cleanup_module);
> +
> +MODULE_LICENSE("GPL v2");
>



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