Re: [PATCH 4/5] nvmet-rdma: add a NVMe over Fabrics RDMA target driver

Sagi Grimberg
2016-06-07T12:00:39Z

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

On 07/06/16 00:23, Christoph Hellwig wrote:
> This patch implements the RDMA transport for the NVMe over Fabrics target,
> which allows exporting NVMe over Fabrics functionality over RDMA fabrics
> (Infiniband, RoCE, iWARP).
>
> All NVMe logic is in the generic target and this module just provides a
> small glue between it and the generic code in the RDMA subsystem.
>
> Signed-off-by: Armen Baloyan <armenx.baloyan@intel.com>,
> Signed-off-by: Jay Freyensee <james.p.freyensee@intel.com>
> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> drivers/nvme/target/Kconfig | 10 +
> drivers/nvme/target/Makefile | 2 +
> drivers/nvme/target/rdma.c | 1404 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1416 insertions(+)
> create mode 100644 drivers/nvme/target/rdma.c
>
> diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
> index b77ce43..6aa7be0 100644
> --- a/drivers/nvme/target/Kconfig
> +++ b/drivers/nvme/target/Kconfig
> @@ -24,3 +24,13 @@ config NVME_TARGET_LOOP
> to test NVMe host and target side features.
>
> If unsure, say N.
> +
> +config NVME_TARGET_RDMA
> + tristate "NVMe over Fabrics RDMA target support"
> + depends on INFINIBAND
> + select NVME_TARGET
> + help
> + This enables the NVMe RDMA target support, which allows exporting NVMe
> + devices over RDMA.
> +
> + If unsure, say N.
> diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
> index e49ba60..b7a0623 100644
> --- a/drivers/nvme/target/Makefile
> +++ b/drivers/nvme/target/Makefile
> @@ -1,7 +1,9 @@
>
> obj-$(CONFIG_NVME_TARGET) += nvmet.o
> obj-$(CONFIG_NVME_TARGET_LOOP) += nvme-loop.o
> +obj-$(CONFIG_NVME_TARGET_RDMA) += nvmet-rdma.o
>
> nvmet-y += core.o configfs.o admin-cmd.o io-cmd.o fabrics-cmd.o \
> discovery.o
> nvme-loop-y += loop.o
> +nvmet-rdma-y += rdma.o
> diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
> new file mode 100644
> index 0000000..fccb01d
> --- /dev/null
> +++ b/drivers/nvme/target/rdma.c
> @@ -0,0 +1,1404 @@
> +/*
> + * NVMe over Fabrics RDMA target.
> + * 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/atomic.h>
> +#include <linux/ctype.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/nvme.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/wait.h>
> +#include <linux/inet.h>
> +#include <asm/unaligned.h>
> +
> +#include <rdma/ib_verbs.h>
> +#include <rdma/rdma_cm.h>
> +#include <rdma/rw.h>
> +
> +#include <linux/nvme-rdma.h>
> +#include "nvmet.h"
> +
> +/*
> + * We allow up to a page of inline data to go with the SQE
> + */
> +#define NVMET_RDMA_INLINE_DATA_SIZE PAGE_SIZE
> +
> +struct nvmet_rdma_cmd {
> + struct ib_sge sge[2];
> + struct ib_cqe cqe;
> + struct ib_recv_wr wr;
> + struct scatterlist inline_sg;
> + struct page *inline_page;
> + struct nvme_command *nvme_cmd;
> + struct nvmet_rdma_queue *queue;
> +};
> +
> +enum {
> + NVMET_RDMA_REQ_INLINE_DATA = (1 << 0),
> + NVMET_RDMA_REQ_INVALIDATE_RKEY = (1 << 1),
> +};
> +
> +struct nvmet_rdma_rsp {
> + struct ib_sge send_sge;
> + struct ib_cqe send_cqe;
> + struct ib_send_wr send_wr;
> +
> + struct nvmet_rdma_cmd *cmd;
> + struct nvmet_rdma_queue *queue;
> +
> + struct ib_cqe read_cqe;
> + struct rdma_rw_ctx rw;
> +
> + struct nvmet_req req;
> +
> + u8 n_rdma;
> + u32 flags;
> + u32 invalidate_rkey;
> +
> + struct list_head wait_list;
> + struct list_head free_list;
> +};
> +
> +enum nvmet_rdma_queue_state {
> + NVMET_RDMA_Q_CONNECTING,
> + NVMET_RDMA_Q_LIVE,
> + NVMET_RDMA_Q_DISCONNECTING,
> +};
> +
> +struct nvmet_rdma_queue {
> + struct rdma_cm_id *cm_id;
> + struct nvmet_port *port;
> + struct ib_cq *cq;
> + atomic_t sq_wr_avail;
> + struct nvmet_rdma_device *dev;
> + spinlock_t state_lock;
> + enum nvmet_rdma_queue_state state;
> + struct nvmet_cq nvme_cq;
> + struct nvmet_sq nvme_sq;
> +
> + struct nvmet_rdma_rsp *rsps;
> + struct list_head free_rsps;
> + spinlock_t rsps_lock;
> + struct nvmet_rdma_cmd *cmds;
> +
> + struct work_struct release_work;
> + struct list_head rsp_wait_list;
> + struct list_head rsp_wr_wait_list;
> + spinlock_t rsp_wr_wait_lock;
> +
> + int idx;
> + int host_qid;
> + int recv_queue_size;
> + int send_queue_size;
> +
> + struct list_head queue_list;
> +};
> +
> +struct nvmet_rdma_device {
> + struct ib_device *device;
> + struct ib_pd *pd;
> + struct ib_srq *srq;
> + struct nvmet_rdma_cmd *srq_cmds;
> + size_t srq_size;
> + struct kref ref;
> + struct list_head entry;
> +};
> +
> +static bool nvmet_rdma_use_srq;
> +module_param_named(use_srq, nvmet_rdma_use_srq, bool, 0444);
> +MODULE_PARM_DESC(use_srq, "Use shared receive queue.");
> +
> +static DEFINE_IDA(nvmet_rdma_queue_ida);
> +static LIST_HEAD(nvmet_rdma_queue_list);
> +static DEFINE_MUTEX(nvmet_rdma_queue_mutex);
> +
> +static LIST_HEAD(device_list);
> +static DEFINE_MUTEX(device_list_mutex);
> +
> +static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp);
> +static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc);
> +static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc);
> +static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc);
> +static void nvmet_rdma_qp_event(struct ib_event *event, void *priv);
> +
> +static struct nvmet_fabrics_ops nvmet_rdma_ops;
> +
> +/* XXX: really should move to a generic header sooner or later.. */
> +static inline u32 get_unaligned_le24(const u8 *p)
> +{
> + return (u32)p[0] | (u32)p[1] << 8 | (u32)p[2] << 16;
> +}
> +
> +static inline bool nvmet_rdma_need_data_in(struct nvmet_rdma_rsp *rsp)
> +{
> + return nvme_is_write(rsp->req.cmd) &&
> + rsp->req.data_len &&
> + !(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
> +}
> +
> +static inline bool nvmet_rdma_need_data_out(struct nvmet_rdma_rsp *rsp)
> +{
> + return !nvme_is_write(rsp->req.cmd) &&
> + rsp->req.data_len &&
> + !rsp->req.rsp->status &&
> + !(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
> +}
> +
> +static inline struct nvmet_rdma_rsp *
> +nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue)
> +{
> + struct nvmet_rdma_rsp *rsp;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&queue->rsps_lock, flags);
> + rsp = list_first_entry(&queue->free_rsps,
> + struct nvmet_rdma_rsp, free_list);
> + list_del(&rsp->free_list);
> + spin_unlock_irqrestore(&queue->rsps_lock, flags);
> +
> + return rsp;
> +}
> +
> +static inline void
> +nvmet_rdma_put_rsp(struct nvmet_rdma_rsp *rsp)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&rsp->queue->rsps_lock, flags);
> + list_add_tail(&rsp->free_list, &rsp->queue->free_rsps);
> + spin_unlock_irqrestore(&rsp->queue->rsps_lock, flags);
> +}
> +
> +static void nvmet_rdma_free_sgl(struct scatterlist *sgl, unsigned int nents)
> +{
> + struct scatterlist *sg;
> + int count;
> +
> + if (!sgl || !nents)
> + return;
> +
> + for_each_sg(sgl, sg, nents, count)
> + __free_page(sg_page(sg));
> + kfree(sgl);
> +}
> +
> +static int nvmet_rdma_alloc_sgl(struct scatterlist **sgl, unsigned int *nents,
> + u32 length)
> +{
> + struct scatterlist *sg;
> + struct page *page;
> + unsigned int nent;
> + int i = 0;
> +
> + nent = DIV_ROUND_UP(length, PAGE_SIZE);
> + sg = kmalloc_array(nent, sizeof(struct scatterlist), GFP_KERNEL);
> + if (!sg)
> + goto out;
> +
> + sg_init_table(sg, nent);
> +
> + while (length) {
> + u32 page_len = min_t(u32, length, PAGE_SIZE);
> +
> + page = alloc_page(GFP_KERNEL);
> + if (!page)
> + goto out_free_pages;
> +
> + sg_set_page(&sg[i], page, page_len, 0);
> + length -= page_len;
> + i++;
> + }
> + *sgl = sg;
> + *nents = nent;
> + return 0;
> +
> +out_free_pages:
> + while (i > 0) {
> + i--;
> + __free_page(sg_page(&sg[i]));
> + }
> + kfree(sg);
> +out:
> + return NVME_SC_INTERNAL;
> +}
> +
> +static int nvmet_rdma_alloc_cmd(struct nvmet_rdma_device *ndev,
> + struct nvmet_rdma_cmd *c, bool admin)
> +{
> + /* NVMe command / RDMA RECV */
> + c->nvme_cmd = kmalloc(sizeof(*c->nvme_cmd), GFP_KERNEL);
> + if (!c->nvme_cmd)
> + goto out;
> +
> + c->sge[0].addr = ib_dma_map_single(ndev->device, c->nvme_cmd,
> + sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
> + if (ib_dma_mapping_error(ndev->device, c->sge[0].addr))
> + goto out_free_cmd;
> +
> + c->sge[0].length = sizeof(*c->nvme_cmd);
> + c->sge[0].lkey = ndev->pd->local_dma_lkey;
> +
> + if (!admin) {
> + c->inline_page = alloc_pages(GFP_KERNEL,
> + get_order(NVMET_RDMA_INLINE_DATA_SIZE));
> + if (!c->inline_page)
> + goto out_unmap_cmd;
> + c->sge[1].addr = ib_dma_map_page(ndev->device,
> + c->inline_page, 0, NVMET_RDMA_INLINE_DATA_SIZE,
> + DMA_FROM_DEVICE);
> + if (ib_dma_mapping_error(ndev->device, c->sge[1].addr))
> + goto out_free_inline_page;
> + c->sge[1].length = NVMET_RDMA_INLINE_DATA_SIZE;
> + c->sge[1].lkey = ndev->pd->local_dma_lkey;
> + }
> +
> + c->cqe.done = nvmet_rdma_recv_done;
> +
> + c->wr.wr_cqe = &c->cqe;
> + c->wr.sg_list = c->sge;
> + c->wr.num_sge = admin ? 1 : 2;
> +
> + return 0;
> +
> +out_free_inline_page:
> + if (!admin) {
> + __free_pages(c->inline_page,
> + get_order(NVMET_RDMA_INLINE_DATA_SIZE));
> + }
> +out_unmap_cmd:
> + ib_dma_unmap_single(ndev->device, c->sge[0].addr,
> + sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
> +out_free_cmd:
> + kfree(c->nvme_cmd);
> +
> +out:
> + return -ENOMEM;
> +}
> +
> +static void nvmet_rdma_free_cmd(struct nvmet_rdma_device *ndev,
> + struct nvmet_rdma_cmd *c, bool admin)
> +{
> + if (!admin) {
> + ib_dma_unmap_page(ndev->device, c->sge[1].addr,
> + NVMET_RDMA_INLINE_DATA_SIZE, DMA_FROM_DEVICE);
> + __free_pages(c->inline_page,
> + get_order(NVMET_RDMA_INLINE_DATA_SIZE));
> + }
> + ib_dma_unmap_single(ndev->device, c->sge[0].addr,
> + sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
> + kfree(c->nvme_cmd);
> +}
> +
> +static struct nvmet_rdma_cmd *
> +nvmet_rdma_alloc_cmds(struct nvmet_rdma_device *ndev,
> + int nr_cmds, bool admin)
> +{
> + struct nvmet_rdma_cmd *cmds;
> + int ret = -EINVAL, i;
> +
> + cmds = kcalloc(nr_cmds, sizeof(struct nvmet_rdma_cmd), GFP_KERNEL);
> + if (!cmds)
> + goto out;
> +
> + for (i = 0; i < nr_cmds; i++) {
> + ret = nvmet_rdma_alloc_cmd(ndev, cmds + i, admin);
> + if (ret)
> + goto out_free;
> + }
> +
> + return cmds;
> +
> +out_free:
> + while (--i >= 0)
> + nvmet_rdma_free_cmd(ndev, cmds + i, admin);
> + kfree(cmds);
> +out:
> + return ERR_PTR(ret);
> +}
> +
> +static void nvmet_rdma_free_cmds(struct nvmet_rdma_device *ndev,
> + struct nvmet_rdma_cmd *cmds, int nr_cmds, bool admin)
> +{
> + int i;
> +
> + for (i = 0; i < nr_cmds; i++)
> + nvmet_rdma_free_cmd(ndev, cmds + i, admin);
> + kfree(cmds);
> +}
> +
> +static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev,
> + struct nvmet_rdma_rsp *r)
> +{
> + /* NVMe CQE / RDMA SEND */
> + r->req.rsp = kmalloc(sizeof(*r->req.rsp), GFP_KERNEL);
> + if (!r->req.rsp)
> + goto out;
> +
> + r->send_sge.addr = ib_dma_map_single(ndev->device, r->req.rsp,
> + sizeof(*r->req.rsp), DMA_TO_DEVICE);
> + if (ib_dma_mapping_error(ndev->device, r->send_sge.addr))
> + goto out_free_rsp;
> +
> + r->send_sge.length = sizeof(*r->req.rsp);
> + r->send_sge.lkey = ndev->pd->local_dma_lkey;
> +
> + r->send_cqe.done = nvmet_rdma_send_done;
> +
> + r->send_wr.wr_cqe = &r->send_cqe;
> + r->send_wr.sg_list = &r->send_sge;
> + r->send_wr.num_sge = 1;
> + r->send_wr.send_flags = IB_SEND_SIGNALED;
> +
> + /* Data In / RDMA READ */
> + r->read_cqe.done = nvmet_rdma_read_data_done;
> + return 0;
> +
> +out_free_rsp:
> + kfree(r->req.rsp);
> +out:
> + return -ENOMEM;
> +}
> +
> +static void nvmet_rdma_free_rsp(struct nvmet_rdma_device *ndev,
> + struct nvmet_rdma_rsp *r)
> +{
> + ib_dma_unmap_single(ndev->device, r->send_sge.addr,
> + sizeof(*r->req.rsp), DMA_TO_DEVICE);
> + kfree(r->req.rsp);
> +}
> +
> +static int
> +nvmet_rdma_alloc_rsps(struct nvmet_rdma_queue *queue)
> +{
> + struct nvmet_rdma_device *ndev = queue->dev;
> + int nr_rsps = queue->recv_queue_size * 2;
> + int ret = -EINVAL, i;
> +
> + queue->rsps = kcalloc(nr_rsps, sizeof(struct nvmet_rdma_rsp),
> + GFP_KERNEL);
> + if (!queue->rsps)
> + goto out;
> +
> + for (i = 0; i < nr_rsps; i++) {
> + struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
> +
> + ret = nvmet_rdma_alloc_rsp(ndev, rsp);
> + if (ret)
> + goto out_free;
> +
> + list_add_tail(&rsp->free_list, &queue->free_rsps);
> + }
> +
> + return 0;
> +
> +out_free:
> + while (--i >= 0) {
> + struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
> +
> + list_del(&rsp->free_list);
> + nvmet_rdma_free_rsp(ndev, rsp);
> + }
> + kfree(queue->rsps);
> +out:
> + return ret;
> +}
> +
> +static void nvmet_rdma_free_rsps(struct nvmet_rdma_queue *queue)
> +{
> + struct nvmet_rdma_device *ndev = queue->dev;
> + int i, nr_rsps = queue->recv_queue_size * 2;
> +
> + for (i = 0; i < nr_rsps; i++) {
> + struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
> +
> + list_del(&rsp->free_list);
> + nvmet_rdma_free_rsp(ndev, rsp);
> + }
> + kfree(queue->rsps);
> +}
> +
> +static int nvmet_rdma_post_recv(struct nvmet_rdma_device *ndev,
> + struct nvmet_rdma_cmd *cmd)
> +{
> + struct ib_recv_wr *bad_wr;
> +
> + if (ndev->srq)
> + return ib_post_srq_recv(ndev->srq, &cmd->wr, &bad_wr);
> + return ib_post_recv(cmd->queue->cm_id->qp, &cmd->wr, &bad_wr);
> +}
> +
> +static void nvmet_rdma_process_wr_wait_list(struct nvmet_rdma_queue *queue)
> +{
> + spin_lock(&queue->rsp_wr_wait_lock);
> + while (!list_empty(&queue->rsp_wr_wait_list)) {
> + struct nvmet_rdma_rsp *rsp;
> + bool ret;
> +
> + rsp = list_entry(queue->rsp_wr_wait_list.next,
> + struct nvmet_rdma_rsp, wait_list);
> + list_del(&rsp->wait_list);
> +
> + spin_unlock(&queue->rsp_wr_wait_lock);
> + ret = nvmet_rdma_execute_command(rsp);
> + spin_lock(&queue->rsp_wr_wait_lock);
> +
> + if (!ret) {
> + list_add(&rsp->wait_list, &queue->rsp_wr_wait_list);
> + break;
> + }
> + }
> + spin_unlock(&queue->rsp_wr_wait_lock);
> +}
> +
> +
> +static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp)
> +{
> + struct nvmet_rdma_queue *queue = rsp->queue;
> +
> + atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
> +
> + if (rsp->n_rdma) {
> + rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
> + queue->cm_id->port_num, rsp->req.sg,
> + rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
> + }
> +
> + if (rsp->req.sg != &rsp->cmd->inline_sg)
> + nvmet_rdma_free_sgl(rsp->req.sg, rsp->req.sg_cnt);
> +
> + if (unlikely(!list_empty_careful(&queue->rsp_wr_wait_list)))
> + nvmet_rdma_process_wr_wait_list(queue);
> +
> + nvmet_rdma_put_rsp(rsp);
> +}
> +
> +static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
> +{
> + struct nvmet_rdma_rsp *rsp =
> + container_of(wc->wr_cqe, struct nvmet_rdma_rsp, send_cqe);
> +
> + nvmet_rdma_release_rsp(rsp);
> +}
> +
> +static void nvmet_rdma_queue_response(struct nvmet_req *req)
> +{
> + struct nvmet_rdma_rsp *rsp =
> + container_of(req, struct nvmet_rdma_rsp, req);
> + struct rdma_cm_id *cm_id = rsp->queue->cm_id;
> + struct ib_send_wr *first_wr, *bad_wr;
> +
> + if (rsp->flags & NVMET_RDMA_REQ_INVALIDATE_RKEY) {
> + rsp->send_wr.opcode = IB_WR_SEND_WITH_INV;
> + rsp->send_wr.ex.invalidate_rkey = rsp->invalidate_rkey;
> + } else {
> + rsp->send_wr.opcode = IB_WR_SEND;
> + }
> +
> + if (nvmet_rdma_need_data_out(rsp))
> + first_wr = rdma_rw_ctx_wrs(&rsp->rw, cm_id->qp,
> + cm_id->port_num, NULL, &rsp->send_wr);
> + else
> + first_wr = &rsp->send_wr;
> +
> + nvmet_rdma_post_recv(rsp->queue->dev, rsp->cmd);
> + if (ib_post_send(cm_id->qp, first_wr, &bad_wr)) {
> + pr_err("sending cmd response failed\n");
> + nvmet_rdma_release_rsp(rsp);
> + }
> +}
> +
> +static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc)
> +{
> + struct nvmet_rdma_rsp *rsp =
> + container_of(wc->wr_cqe, struct nvmet_rdma_rsp, read_cqe);
> + struct nvmet_rdma_queue *queue = cq->cq_context;
> +
> + WARN_ON(rsp->n_rdma <= 0);
> + atomic_add(rsp->n_rdma, &queue->sq_wr_avail);
> + rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
> + queue->cm_id->port_num, rsp->req.sg,
> + rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
> + rsp->n_rdma = 0;
> +
> + if (unlikely(wc->status != IB_WC_SUCCESS &&
> + wc->status != IB_WC_WR_FLUSH_ERR)) {
> + pr_info("RDMA READ for CQE 0x%p failed with status %s (%d).\n",
> + wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
> + nvmet_req_complete(&rsp->req, NVME_SC_DATA_XFER_ERROR);
> + return;
> + }
> +
> + rsp->req.execute(&rsp->req);
> +}
> +
> +static void nvmet_rdma_use_inline_sg(struct nvmet_rdma_rsp *rsp, u32 len,
> + u64 off)
> +{
> + sg_init_table(&rsp->cmd->inline_sg, 1);
> + sg_set_page(&rsp->cmd->inline_sg, rsp->cmd->inline_page, len, off);
> + rsp->req.sg = &rsp->cmd->inline_sg;
> + rsp->req.sg_cnt = 1;
> +}
> +
> +static u16 nvmet_rdma_map_sgl_inline(struct nvmet_rdma_rsp *rsp)
> +{
> + struct nvme_sgl_desc *sgl = &rsp->req.cmd->common.dptr.sgl;
> + u64 off = le64_to_cpu(sgl->addr);
> + u32 len = le32_to_cpu(sgl->length);
> +
> + if (!nvme_is_write(rsp->req.cmd))
> + return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
> +
> + if (off + len > NVMET_RDMA_INLINE_DATA_SIZE) {
> + pr_err("invalid inline data offset!\n");
> + return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
> + }
> +
> + /* no data command? */
> + if (!len)
> + return 0;
> +
> + nvmet_rdma_use_inline_sg(rsp, len, off);
> + rsp->flags |= NVMET_RDMA_REQ_INLINE_DATA;
> + return 0;
> +}
> +
> +static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp,
> + struct nvme_keyed_sgl_desc *sgl, bool invalidate)
> +{
> + struct rdma_cm_id *cm_id = rsp->queue->cm_id;
> + u64 addr = le64_to_cpu(sgl->addr);
> + u32 len = get_unaligned_le24(sgl->length);
> + u32 key = get_unaligned_le32(sgl->key);
> + int ret;
> + u16 status;
> +
> + /* no data command? */
> + if (!len)
> + return 0;
> +
> + /* use the already allocated data buffer if possible */
> + if (len <= NVMET_RDMA_INLINE_DATA_SIZE && rsp->queue->host_qid) {
> + nvmet_rdma_use_inline_sg(rsp, len, 0);
> + } else {
> + status = nvmet_rdma_alloc_sgl(&rsp->req.sg, &rsp->req.sg_cnt,
> + len);
> + if (status)
> + return status;
> + }
> +
> + ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num,
> + rsp->req.sg, rsp->req.sg_cnt, 0, addr, key,
> + nvmet_data_dir(&rsp->req));
> + if (ret < 0)
> + return NVME_SC_INTERNAL;
> + rsp->n_rdma += ret;
> +
> + if (invalidate) {
> + rsp->invalidate_rkey = key;
> + rsp->flags |= NVMET_RDMA_REQ_INVALIDATE_RKEY;
> + }
> +
> + return 0;
> +}
> +
> +static u16 nvmet_rdma_map_sgl(struct nvmet_rdma_rsp *rsp)
> +{
> + struct nvme_keyed_sgl_desc *sgl = &rsp->req.cmd->common.dptr.ksgl;
> +
> + switch (sgl->type >> 4) {
> + case NVME_SGL_FMT_DATA_DESC:
> + switch (sgl->type & 0xf) {
> + case NVME_SGL_FMT_OFFSET:
> + return nvmet_rdma_map_sgl_inline(rsp);
> + default:
> + pr_err("invalid SGL subtype: %#x\n", sgl->type);
> + return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
> + }
> + case NVME_KEY_SGL_FMT_DATA_DESC:
> + switch (sgl->type & 0xf) {
> + case NVME_SGL_FMT_ADDRESS | NVME_SGL_FMT_INVALIDATE:
> + return nvmet_rdma_map_sgl_keyed(rsp, sgl, true);
> + case NVME_SGL_FMT_ADDRESS:
> + return nvmet_rdma_map_sgl_keyed(rsp, sgl, false);
> + default:
> + pr_err("invalid SGL subtype: %#x\n", sgl->type);
> + return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
> + }
> + default:
> + pr_err("invalid SGL type: %#x\n", sgl->type);
> + return NVME_SC_SGL_INVALID_TYPE | NVME_SC_DNR;
> + }
> +}
> +
> +static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp)
> +{
> + struct nvmet_rdma_queue *queue = rsp->queue;
> +
> + if (unlikely(atomic_sub_return(1 + rsp->n_rdma,
> + &queue->sq_wr_avail) < 0)) {
> + pr_debug("IB send queue full (needed %d): queue %u cntlid %u\n",
> + 1 + rsp->n_rdma, queue->idx,
> + queue->nvme_sq.ctrl->cntlid);
> + atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
> + return false;
> + }
> +
> + if (nvmet_rdma_need_data_in(rsp)) {
> + if (rdma_rw_ctx_post(&rsp->rw, queue->cm_id->qp,
> + queue->cm_id->port_num, &rsp->read_cqe, NULL))
> + nvmet_req_complete(&rsp->req, NVME_SC_DATA_XFER_ERROR);
> + } else {
> + rsp->req.execute(&rsp->req);
> + }
> +
> + return true;
> +}
> +
> +static void nvmet_rdma_handle_command(struct nvmet_rdma_queue *queue,
> + struct nvmet_rdma_rsp *cmd)
> +{
> + u16 status;
> +
> + cmd->queue = queue;
> + cmd->n_rdma = 0;
> + cmd->req.port = queue->port;
> +
> + if (!nvmet_req_init(&cmd->req, &queue->nvme_cq,
> + &queue->nvme_sq, &nvmet_rdma_ops))
> + return;
> +
> + status = nvmet_rdma_map_sgl(cmd);
> + if (status)
> + goto out_err;
> +
> + if (unlikely(!nvmet_rdma_execute_command(cmd))) {
> + spin_lock(&queue->rsp_wr_wait_lock);
> + list_add_tail(&cmd->wait_list, &queue->rsp_wr_wait_list);
> + spin_unlock(&queue->rsp_wr_wait_lock);
> + }
> +
> + return;
> +
> +out_err:
> + nvmet_req_complete(&cmd->req, status);
> +}
> +
> +static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
> +{
> + struct nvmet_rdma_cmd *cmd =
> + container_of(wc->wr_cqe, struct nvmet_rdma_cmd, cqe);
> + struct nvmet_rdma_queue *queue = cq->cq_context;
> + struct nvmet_rdma_rsp *rsp;
> +
> + if (unlikely(wc->status != IB_WC_SUCCESS))
> + return;
> +
> + if (unlikely(wc->byte_len < sizeof(struct nvme_command))) {
> + pr_err("Ctrl Fatal Error: capsule size less than 64 bytes\n");
> + if (queue->nvme_sq.ctrl)
> + nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
> + return;
> + }
> +
> + cmd->queue = queue;
> + rsp = nvmet_rdma_get_rsp(queue);
> + rsp->cmd = cmd;
> + rsp->flags = 0;
> + rsp->req.cmd = cmd->nvme_cmd;
> +
> + if (unlikely(queue->state != NVMET_RDMA_Q_LIVE)) {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&queue->state_lock, flags);
> + if (queue->state == NVMET_RDMA_Q_CONNECTING)
> + list_add_tail(&rsp->wait_list, &queue->rsp_wait_list);
> + spin_unlock_irqrestore(&queue->state_lock, flags);
> + return;
> + }
> +
> + nvmet_rdma_handle_command(queue, rsp);
> +}
> +
> +static void nvmet_rdma_destroy_srq(struct nvmet_rdma_device *ndev)
> +{
> + if (!ndev->srq)
> + return;
> +
> + nvmet_rdma_free_cmds(ndev, ndev->srq_cmds, ndev->srq_size, false);
> + ib_destroy_srq(ndev->srq);
> +}
> +
> +static int nvmet_rdma_init_srq(struct nvmet_rdma_device *ndev)
> +{
> + struct ib_srq_init_attr srq_attr = { NULL, };
> + struct ib_srq *srq;
> + size_t srq_size;
> + int ret, i;
> +
> + srq_size = 4095; /* XXX: tune */
> +
> + srq_attr.attr.max_wr = srq_size;
> + srq_attr.attr.max_sge = 2;
> + srq_attr.attr.srq_limit = 0;
> + srq_attr.srq_type = IB_SRQT_BASIC;
> + srq = ib_create_srq(ndev->pd, &srq_attr);
> + if (IS_ERR(srq)) {
> + /*
> + * If SRQs aren't supported we just go ahead and use normal
> + * non-shared receive queues.
> + */
> + pr_info("SRQ requested but not supported.\n");
> + return 0;
> + }
> +
> + ndev->srq_cmds = nvmet_rdma_alloc_cmds(ndev, srq_size, false);
> + if (IS_ERR(ndev->srq_cmds)) {
> + ret = PTR_ERR(ndev->srq_cmds);
> + goto out_destroy_srq;
> + }
> +
> + ndev->srq = srq;
> + ndev->srq_size = srq_size;
> +
> + for (i = 0; i < srq_size; i++)
> + nvmet_rdma_post_recv(ndev, &ndev->srq_cmds[i]);
> +
> + return 0;
> +
> +out_destroy_srq:
> + ib_destroy_srq(srq);
> + return ret;
> +}
> +
> +static void nvmet_rdma_free_dev(struct kref *ref)
> +{
> + struct nvmet_rdma_device *ndev =
> + container_of(ref, struct nvmet_rdma_device, ref);
> +
> + mutex_lock(&device_list_mutex);
> + list_del(&ndev->entry);
> + mutex_unlock(&device_list_mutex);
> +
> + nvmet_rdma_destroy_srq(ndev);
> + ib_dealloc_pd(ndev->pd);
> +
> + kfree(ndev);
> +}
> +
> +static struct nvmet_rdma_device *
> +nvmet_rdma_find_get_device(struct rdma_cm_id *cm_id)
> +{
> + struct nvmet_rdma_device *ndev;
> + int ret;
> +
> + mutex_lock(&device_list_mutex);
> + list_for_each_entry(ndev, &device_list, entry) {
> + if (ndev->device->node_guid == cm_id->device->node_guid &&
> + kref_get_unless_zero(&ndev->ref))
> + goto out_unlock;
> + }
> +
> + ndev = kzalloc(sizeof(*ndev), GFP_KERNEL);
> + if (!ndev)
> + goto out_err;
> +
> + ndev->device = cm_id->device;
> + kref_init(&ndev->ref);
> +
> + ndev->pd = ib_alloc_pd(ndev->device);
> + if (IS_ERR(ndev->pd))
> + goto out_free_dev;
> +
> + if (nvmet_rdma_use_srq) {
> + ret = nvmet_rdma_init_srq(ndev);
> + if (ret)
> + goto out_free_pd;
> + }
> +
> + list_add(&ndev->entry, &device_list);
> +out_unlock:
> + mutex_unlock(&device_list_mutex);
> + pr_debug("added %s.\n", ndev->device->name);
> + 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 int nvmet_rdma_create_queue_ib(struct nvmet_rdma_queue *queue)
> +{
> + struct ib_qp_init_attr qp_attr;
> + struct nvmet_rdma_device *ndev = queue->dev;
> + int comp_vector, nr_cqe, ret, i;
> +
> + /*
> + * Spread the io queues across completion vectors,
> + * but still keep all admin queues on vector 0.
> + */
> + comp_vector = !queue->host_qid ? 0 :
> + queue->idx % ndev->device->num_comp_vectors;
> +
> + /*
> + * Reserve CQ slots for RECV + RDMA_READ/RDMA_WRITE + RDMA_SEND.
> + */
> + nr_cqe = queue->recv_queue_size + 2 * queue->send_queue_size;
> +
> + queue->cq = ib_alloc_cq(ndev->device, queue,
> + nr_cqe + 1, comp_vector,
> + IB_POLL_WORKQUEUE);
> + if (IS_ERR(queue->cq)) {
> + ret = PTR_ERR(queue->cq);
> + pr_err("failed to create CQ cqe= %d ret= %d\n",
> + nr_cqe + 1, ret);
> + goto out;
> + }
> +
> + memset(&qp_attr, 0, sizeof(qp_attr));
> + qp_attr.qp_context = queue;
> + qp_attr.event_handler = nvmet_rdma_qp_event;
> + qp_attr.send_cq = queue->cq;
> + qp_attr.recv_cq = queue->cq;
> + qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
> + qp_attr.qp_type = IB_QPT_RC;
> + /* +1 for drain */
> + qp_attr.cap.max_send_wr = queue->send_queue_size + 1;
> + qp_attr.cap.max_rdma_ctxs = queue->send_queue_size;
> + qp_attr.cap.max_send_sge = max(ndev->device->attrs.max_sge_rd,
> + ndev->device->attrs.max_sge);
> +
> + if (ndev->srq) {
> + qp_attr.srq = ndev->srq;
> + } else {
> + /* +1 for drain */
> + qp_attr.cap.max_recv_wr = 1 + queue->recv_queue_size;
> + qp_attr.cap.max_recv_sge = 2;
> + }
> +
> + ret = rdma_create_qp(queue->cm_id, ndev->pd, &qp_attr);
> + if (ret) {
> + pr_err("failed to create_qp ret= %d\n", ret);
> + goto err_destroy_cq;
> + }
> +
> + atomic_set(&queue->sq_wr_avail, qp_attr.cap.max_send_wr);
> +
> + pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
> + __func__, queue->cq->cqe, qp_attr.cap.max_send_sge,
> + qp_attr.cap.max_send_wr, queue->cm_id);
> +
> + if (!ndev->srq) {
> + for (i = 0; i < queue->recv_queue_size; i++) {
> + queue->cmds[i].queue = queue;
> + nvmet_rdma_post_recv(ndev, &queue->cmds[i]);
> + }
> + }
> +
> +out:
> + return ret;
> +
> +err_destroy_cq:
> + ib_free_cq(queue->cq);
> + goto out;
> +}
> +
> +static void nvmet_rdma_destroy_queue_ib(struct nvmet_rdma_queue *queue)
> +{
> + rdma_destroy_qp(queue->cm_id);
> + ib_free_cq(queue->cq);
> +}
> +
> +static void nvmet_rdma_free_queue(struct nvmet_rdma_queue *queue)
> +{
> + pr_info("freeing queue %d\n", queue->idx);
> +
> + nvmet_sq_destroy(&queue->nvme_sq);
> +
> + nvmet_rdma_destroy_queue_ib(queue);
> + if (!queue->dev->srq) {
> + nvmet_rdma_free_cmds(queue->dev, queue->cmds,
> + queue->recv_queue_size,
> + !queue->host_qid);
> + }
> + nvmet_rdma_free_rsps(queue);
> + ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
> + kfree(queue);
> +}
> +
> +static void nvmet_rdma_release_queue_work(struct work_struct *w)
> +{
> + struct nvmet_rdma_queue *queue =
> + container_of(w, struct nvmet_rdma_queue, release_work);
> + struct rdma_cm_id *cm_id = queue->cm_id;
> + struct nvmet_rdma_device *dev = queue->dev;
> +
> + nvmet_rdma_free_queue(queue);
> + rdma_destroy_id(cm_id);
> + kref_put(&dev->ref, nvmet_rdma_free_dev);
> +}
> +
> +static int
> +nvmet_rdma_parse_cm_connect_req(struct rdma_conn_param *conn,
> + struct nvmet_rdma_queue *queue)
> +{
> + struct nvme_rdma_cm_req *req;
> +
> + req = (struct nvme_rdma_cm_req *)conn->private_data;
> + if (!req || conn->private_data_len == 0)
> + return NVME_RDMA_CM_INVALID_LEN;
> +
> + if (le16_to_cpu(req->recfmt) != NVME_RDMA_CM_FMT_1_0)
> + return NVME_RDMA_CM_INVALID_RECFMT;
> +
> + queue->host_qid = le16_to_cpu(req->qid);
> +
> + /*
> + * req->hsqsize corresponds to our recv queue size
> + * req->hrqsize corresponds to our send queue size
> + */
> + queue->recv_queue_size = le16_to_cpu(req->hsqsize);
> + queue->send_queue_size = le16_to_cpu(req->hrqsize);
> +
> + if (!queue->host_qid && queue->recv_queue_size > NVMF_AQ_DEPTH)
> + return NVME_RDMA_CM_INVALID_HSQSIZE;
> +
> + /* XXX: Should we enforce some kind of max for IO queues? */
> +
> + return 0;
> +}
> +
> +static int nvmet_rdma_cm_reject(struct rdma_cm_id *cm_id,
> + enum nvme_rdma_cm_status status)
> +{
> + struct nvme_rdma_cm_rej rej;
> +
> + rej.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
> + rej.sts = cpu_to_le16(status);
> +
> + return rdma_reject(cm_id, (void *)&rej, sizeof(rej));
> +}
> +
> +static struct nvmet_rdma_queue *
> +nvmet_rdma_alloc_queue(struct nvmet_rdma_device *ndev,
> + struct rdma_cm_id *cm_id,
> + struct rdma_cm_event *event)
> +{
> + struct nvmet_rdma_queue *queue;
> + int ret;
> +
> + queue = kzalloc(sizeof(*queue), GFP_KERNEL);
> + if (!queue) {
> + ret = NVME_RDMA_CM_NO_RSC;
> + goto out_reject;
> + }
> +
> + ret = nvmet_sq_init(&queue->nvme_sq);
> + if (ret)
> + goto out_free_queue;
> +
> + ret = nvmet_rdma_parse_cm_connect_req(&event->param.conn, queue);
> + if (ret)
> + goto out_destroy_sq;
> +
> + /*
> + * Schedules the actual release because calling rdma_destroy_id from
> + * inside a CM callback would trigger a deadlock. (great API design..)
> + */
> + INIT_WORK(&queue->release_work, nvmet_rdma_release_queue_work);
> + queue->dev = ndev;
> + queue->cm_id = cm_id;
> +
> + spin_lock_init(&queue->state_lock);
> + queue->state = NVMET_RDMA_Q_CONNECTING;
> + INIT_LIST_HEAD(&queue->rsp_wait_list);
> + INIT_LIST_HEAD(&queue->rsp_wr_wait_list);
> + spin_lock_init(&queue->rsp_wr_wait_lock);
> + INIT_LIST_HEAD(&queue->free_rsps);
> + spin_lock_init(&queue->rsps_lock);
> +
> + queue->idx = ida_simple_get(&nvmet_rdma_queue_ida, 0, 0, GFP_KERNEL);
> + if (queue->idx < 0) {
> + ret = NVME_RDMA_CM_NO_RSC;
> + goto out_free_queue;
> + }
> +
> + ret = nvmet_rdma_alloc_rsps(queue);
> + if (ret) {
> + ret = NVME_RDMA_CM_NO_RSC;
> + goto out_ida_remove;
> + }
> +
> + if (!ndev->srq) {
> + queue->cmds = nvmet_rdma_alloc_cmds(ndev,
> + queue->recv_queue_size,
> + !queue->host_qid);
> + if (IS_ERR(queue->cmds)) {
> + ret = NVME_RDMA_CM_NO_RSC;
> + goto out_free_cmds;
> + }
> + }
> +
> + ret = nvmet_rdma_create_queue_ib(queue);
> + if (ret) {
> + pr_err("%s: creating RDMA queue failed (%d).\n",
> + __func__, ret);
> + ret = NVME_RDMA_CM_NO_RSC;
> + goto out_free_cmds;
> + }
> +
> + return queue;
> +
> +out_free_cmds:
> + if (!ndev->srq) {
> + nvmet_rdma_free_cmds(queue->dev, queue->cmds,
> + queue->recv_queue_size,
> + !queue->host_qid);
> + }
> +out_ida_remove:
> + ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
> +out_destroy_sq:
> + nvmet_sq_destroy(&queue->nvme_sq);
> +out_free_queue:
> + kfree(queue);
> +out_reject:
> + nvmet_rdma_cm_reject(cm_id, ret);
> + return NULL;
> +}
> +
> +static void nvmet_rdma_qp_event(struct ib_event *event, void *priv)
> +{
> + struct nvmet_rdma_queue *queue = priv;
> +
> + switch (event->event) {
> + case IB_EVENT_COMM_EST:
> + rdma_notify(queue->cm_id, event->event);
> + break;
> + default:
> + pr_err("received unrecognized IB QP event %d\n", event->event);
> + break;
> + }
> +}
> +
> +static int nvmet_rdma_cm_accept(struct rdma_cm_id *cm_id,
> + struct nvmet_rdma_queue *queue,
> + struct rdma_conn_param *p)
> +{
> + struct rdma_conn_param param = { };
> + struct nvme_rdma_cm_rep priv = { };
> + int ret = -ENOMEM;
> +
> + param.rnr_retry_count = 7;
> + param.flow_control = 1;
> + param.initiator_depth = min_t(u8, p->initiator_depth,
> + queue->dev->device->attrs.max_qp_init_rd_atom);
> + param.private_data = &priv;
> + param.private_data_len = sizeof(priv);
> + priv.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
> + priv.crqsize = cpu_to_le16(queue->recv_queue_size);
> +
> + ret = rdma_accept(cm_id, &param);
> + if (ret)
> + pr_err("rdma_accept failed (error code = %d)\n", ret);
> +
> + return ret;
> +}
> +
> +static int nvmet_rdma_queue_connect(struct rdma_cm_id *cm_id,
> + struct rdma_cm_event *event)
> +{
> + struct nvmet_rdma_device *ndev;
> + struct nvmet_rdma_queue *queue;
> + int ret = -EINVAL;
> +
> + ndev = nvmet_rdma_find_get_device(cm_id);
> + if (!ndev) {
> + pr_err("no client data!\n");
> + nvmet_rdma_cm_reject(cm_id, NVME_RDMA_CM_NO_RSC);
> + return -ECONNREFUSED;
> + }
> +
> + queue = nvmet_rdma_alloc_queue(ndev, cm_id, event);
> + if (!queue) {
> + ret = -ENOMEM;
> + goto put_device;
> + }
> + queue->port = cm_id->context;
> +
> + ret = nvmet_rdma_cm_accept(cm_id, queue, &event->param.conn);
> + if (ret)
> + goto release_queue;
> +
> + mutex_lock(&nvmet_rdma_queue_mutex);
> + list_add_tail(&queue->queue_list, &nvmet_rdma_queue_list);
> + mutex_unlock(&nvmet_rdma_queue_mutex);
> +
> + return 0;
> +
> +release_queue:
> + nvmet_rdma_free_queue(queue);
> +put_device:
> + kref_put(&ndev->ref, nvmet_rdma_free_dev);
> +
> + return ret;
> +}
> +
> +static void nvmet_rdma_queue_established(struct nvmet_rdma_queue *queue)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&queue->state_lock, flags);
> + if (queue->state != NVMET_RDMA_Q_CONNECTING) {
> + pr_warn("trying to establish a connected queue\n");
> + goto out_unlock;
> + }
> + queue->state = NVMET_RDMA_Q_LIVE;
> +
> + while (!list_empty(&queue->rsp_wait_list)) {
> + struct nvmet_rdma_rsp *cmd;
> +
> + cmd = list_first_entry(&queue->rsp_wait_list,
> + struct nvmet_rdma_rsp, wait_list);
> + list_del(&cmd->wait_list);
> +
> + spin_unlock_irqrestore(&queue->state_lock, flags);
> + nvmet_rdma_handle_command(queue, cmd);
> + spin_lock_irqsave(&queue->state_lock, flags);
> + }
> +
> +out_unlock:
> + spin_unlock_irqrestore(&queue->state_lock, flags);
> +}
> +
> +static void __nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
> +{
> + bool disconnect = false;
> + unsigned long flags;
> +
> + pr_debug("cm_id= %p queue->state= %d\n", queue->cm_id, queue->state);
> +
> + spin_lock_irqsave(&queue->state_lock, flags);
> + switch (queue->state) {
> + case NVMET_RDMA_Q_CONNECTING:
> + case NVMET_RDMA_Q_LIVE:
> + disconnect = true;
> + queue->state = NVMET_RDMA_Q_DISCONNECTING;
> + break;
> + case NVMET_RDMA_Q_DISCONNECTING:
> + break;
> + }
> + spin_unlock_irqrestore(&queue->state_lock, flags);
> +
> + if (disconnect) {
> + rdma_disconnect(queue->cm_id);
> + ib_drain_qp(queue->cm_id->qp);
> + schedule_work(&queue->release_work);
> + }
> +}
> +
> +static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
> +{
> + bool disconnect = false;
> +
> + mutex_lock(&nvmet_rdma_queue_mutex);
> + if (!list_empty(&queue->queue_list)) {
> + list_del_init(&queue->queue_list);
> + disconnect = true;
> + }
> + mutex_unlock(&nvmet_rdma_queue_mutex);
> +
> + if (disconnect)
> + __nvmet_rdma_queue_disconnect(queue);
> +}
> +
> +static void nvmet_rdma_queue_connect_fail(struct rdma_cm_id *cm_id,
> + struct nvmet_rdma_queue *queue)
> +{
> + WARN_ON_ONCE(queue->state != NVMET_RDMA_Q_CONNECTING);
> +
> + pr_err("failed to connect queue\n");
> + schedule_work(&queue->release_work);
> +}
> +
> +static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
> + struct rdma_cm_event *event)
> +{
> + struct nvmet_rdma_queue *queue = NULL;
> + int ret = 0;
> +
> + if (cm_id->qp)
> + queue = cm_id->qp->qp_context;
> +
> + pr_debug("%s (%d): status %d id %p\n",
> + rdma_event_msg(event->event), event->event,
> + event->status, cm_id);
> +
> + switch (event->event) {
> + case RDMA_CM_EVENT_CONNECT_REQUEST:
> + ret = nvmet_rdma_queue_connect(cm_id, event);
> + break;
> + case RDMA_CM_EVENT_ESTABLISHED:
> + nvmet_rdma_queue_established(queue);
> + break;
> + case RDMA_CM_EVENT_ADDR_CHANGE:
> + case RDMA_CM_EVENT_DISCONNECTED:
> + case RDMA_CM_EVENT_DEVICE_REMOVAL:
> + case RDMA_CM_EVENT_TIMEWAIT_EXIT:
> + /*
> + * We can get the device removal callback even for a
> + * CM ID that we aren't actually using. In that case
> + * the context pointer is NULL, so we shouldn't try
> + * to disconnect a non-existing queue. But we also
> + * need to return 1 so that the core will destroy
> + * it's own ID. What a great API design..
> + */
> + if (queue)
> + nvmet_rdma_queue_disconnect(queue);
> + else
> + ret = 1;
> + break;
> + case RDMA_CM_EVENT_REJECTED:
> + case RDMA_CM_EVENT_UNREACHABLE:
> + case RDMA_CM_EVENT_CONNECT_ERROR:
> + nvmet_rdma_queue_connect_fail(cm_id, queue);
> + break;
> + default:
> + pr_err("received unrecognized RDMA CM event %d\n",
> + event->event);
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static void nvmet_rdma_delete_ctrl(struct nvmet_ctrl *ctrl)
> +{
> + struct nvmet_rdma_queue *queue, *next;
> + static LIST_HEAD(del_list);
> +
> + mutex_lock(&nvmet_rdma_queue_mutex);
> + list_for_each_entry_safe(queue, next,
> + &nvmet_rdma_queue_list, queue_list) {
> + if (queue->nvme_sq.ctrl->cntlid == ctrl->cntlid)
> + list_move_tail(&queue->queue_list, &del_list);
> + }
> + mutex_unlock(&nvmet_rdma_queue_mutex);
> +
> + list_for_each_entry_safe(queue, next, &del_list, queue_list)
> + nvmet_rdma_queue_disconnect(queue);
> +}
> +
> +static int nvmet_rdma_add_port(struct nvmet_port *port)
> +{
> + struct rdma_cm_id *cm_id;
> + struct sockaddr_in addr_in;
> + u16 port_in;
> + int ret;
> +
> + ret = kstrtou16(port->disc_addr.trsvcid, 0, &port_in);
> + if (ret)
> + return ret;
> +
> + addr_in.sin_family = AF_INET;
> + addr_in.sin_addr.s_addr = in_aton(port->disc_addr.traddr);
> + addr_in.sin_port = htons(port_in);
> +
> + cm_id = rdma_create_id(&init_net, nvmet_rdma_cm_handler, port,
> + RDMA_PS_TCP, IB_QPT_RC);
> + if (IS_ERR(cm_id)) {
> + pr_err("CM ID creation failed\n");
> + return PTR_ERR(cm_id);
> + }
> +
> + ret = rdma_bind_addr(cm_id, (struct sockaddr *)&addr_in);
> + if (ret) {
> + pr_err("binding CM ID to %pISpc failed (%d)\n", &addr_in, ret);
> + goto out_destroy_id;
> + }
> +
> + ret = rdma_listen(cm_id, 128);
> + if (ret) {
> + pr_err("listening to %pISpc failed (%d)\n", &addr_in, ret);
> + goto out_destroy_id;
> + }
> +
> + pr_info("enabling port %d (%pISpc)\n",
> + le16_to_cpu(port->disc_addr.portid), &addr_in);
> + port->priv = cm_id;
> + return 0;
> +
> +out_destroy_id:
> + rdma_destroy_id(cm_id);
> + return ret;
> +}
> +
> +static void nvmet_rdma_remove_port(struct nvmet_port *port)
> +{
> + struct rdma_cm_id *cm_id = port->priv;
> +
> + rdma_destroy_id(cm_id);
> +}
> +
> +static struct nvmet_fabrics_ops nvmet_rdma_ops = {
> + .owner = THIS_MODULE,
> + .type = NVMF_TRTYPE_RDMA,
> + .sqe_inline_size = NVMET_RDMA_INLINE_DATA_SIZE,
> + .msdbd = 1,
> + .has_keyed_sgls = 1,
> + .add_port = nvmet_rdma_add_port,
> + .remove_port = nvmet_rdma_remove_port,
> + .queue_response = nvmet_rdma_queue_response,
> + .delete_ctrl = nvmet_rdma_delete_ctrl,
> +};
> +
> +static int __init nvmet_rdma_init(void)
> +{
> + return nvmet_register_transport(&nvmet_rdma_ops);
> +}
> +
> +static void __exit nvmet_rdma_exit(void)
> +{
> + struct nvmet_rdma_queue *queue;
> +
> + nvmet_unregister_transport(&nvmet_rdma_ops);
> +
> + flush_scheduled_work();
> +
> + mutex_lock(&nvmet_rdma_queue_mutex);
> + while ((queue = list_first_entry_or_null(&nvmet_rdma_queue_list,
> + struct nvmet_rdma_queue, queue_list))) {
> + list_del_init(&queue->queue_list);
> +
> + mutex_unlock(&nvmet_rdma_queue_mutex);
> + __nvmet_rdma_queue_disconnect(queue);
> + mutex_lock(&nvmet_rdma_queue_mutex);
> + }
> + mutex_unlock(&nvmet_rdma_queue_mutex);
> +
> + flush_scheduled_work();
> + ida_destroy(&nvmet_rdma_queue_ida);
> +}
> +
> +module_init(nvmet_rdma_init);
> +module_exit(nvmet_rdma_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("nvmet-transport-1"); /* 1 == NVMF_TRTYPE_RDMA */
>