[PATCH 3/3] nvme-loop: add a NVMe loopback host driver
Christoph Hellwig
hch at lst.de
Mon Jun 6 14:22:57 PDT 2016
This patch implements adds nvme-loop which allows to access local devices
exported as NVMe over Fabrics namespaces. This module can be useful for
easy evaluation, testing and also feature experimentation.
To createa nvme-loop device you need to configure the NVMe target to
export a loop port (see the nvmetcli documentaton for that) and then
connect to it using
nvme connect-all -t loop
which requires the very latest nvme-cli version 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/target/Kconfig | 10 +
drivers/nvme/target/Makefile | 2 +
drivers/nvme/target/loop.c | 753 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 765 insertions(+)
create mode 100644 drivers/nvme/target/loop.c
diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
index acf0c07..b77ce43 100644
--- a/drivers/nvme/target/Kconfig
+++ b/drivers/nvme/target/Kconfig
@@ -13,4 +13,14 @@ config NVME_TARGET
To configure the NVMe target you probably want to use the nvmetcli
tool from http://git.infradead.org/users/hch/nvmetcli.git.
+config NVME_TARGET_LOOP
+ tristate "NVMe loopback device support"
+ depends on BLK_DEV_NVME
+ select NVME_TARGET
+ select NVME_FABRICS
+ select SG_POOL
+ help
+ This enables the NVMe loopback device support, which can be useful
+ to test NVMe host and target side features.
+
If unsure, say N.
diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
index b4600b6..e49ba60 100644
--- a/drivers/nvme/target/Makefile
+++ b/drivers/nvme/target/Makefile
@@ -1,5 +1,7 @@
obj-$(CONFIG_NVME_TARGET) += nvmet.o
+obj-$(CONFIG_NVME_TARGET_LOOP) += nvme-loop.o
nvmet-y += core.o configfs.o admin-cmd.o io-cmd.o fabrics-cmd.o \
discovery.o
+nvme-loop-y += loop.o
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
new file mode 100644
index 0000000..08b4fbb
--- /dev/null
+++ b/drivers/nvme/target/loop.c
@@ -0,0 +1,753 @@
+/*
+ * NVMe over Fabrics loopback device.
+ * 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/scatterlist.h>
+#include <linux/delay.h>
+#include <linux/blk-mq.h>
+#include <linux/nvme.h>
+#include <linux/module.h>
+#include <linux/parser.h>
+#include <linux/t10-pi.h>
+#include "nvmet.h"
+#include "../host/nvme.h"
+#include "../host/fabrics.h"
+
+#define NVME_LOOP_AQ_DEPTH 256
+
+#define NVME_LOOP_MAX_SEGMENTS 256
+
+/*
+ * We handle AEN commands ourselves and don't even let the
+ * block layer know about them.
+ */
+#define NVME_LOOP_NR_AEN_COMMANDS 1
+#define NVME_LOOP_AQ_BLKMQ_DEPTH \
+ (NVME_LOOP_AQ_DEPTH - NVME_LOOP_NR_AEN_COMMANDS)
+
+struct nvme_loop_iod {
+ struct nvme_command cmd;
+ struct nvme_completion rsp;
+ struct nvmet_req req;
+ struct nvme_loop_queue *queue;
+ struct work_struct work;
+ struct sg_table sg_table;
+ struct scatterlist first_sgl[];
+};
+
+struct nvme_loop_ctrl {
+ spinlock_t lock;
+ struct nvme_loop_queue *queues;
+ u32 queue_count;
+
+ struct blk_mq_tag_set admin_tag_set;
+
+ struct list_head list;
+ u64 cap;
+ struct blk_mq_tag_set tag_set;
+ struct nvme_loop_iod async_event_iod;
+ struct nvme_ctrl ctrl;
+
+ struct nvmet_ctrl *target_ctrl;
+ struct work_struct delete_work;
+ struct work_struct reset_work;
+};
+
+static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
+{
+ return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
+}
+
+struct nvme_loop_queue {
+ struct nvmet_cq nvme_cq;
+ struct nvmet_sq nvme_sq;
+ struct nvme_loop_ctrl *ctrl;
+};
+
+static struct nvmet_port *nvmet_loop_port;
+
+static LIST_HEAD(nvme_loop_ctrl_list);
+static DEFINE_MUTEX(nvme_loop_ctrl_mutex);
+
+static void nvme_loop_queue_response(struct nvmet_req *nvme_req);
+static void nvme_loop_delete_ctrl(struct nvmet_ctrl *ctrl);
+
+static struct nvmet_fabrics_ops nvme_loop_ops;
+
+static inline int nvme_loop_queue_idx(struct nvme_loop_queue *queue)
+{
+ return queue - queue->ctrl->queues;
+}
+
+static void nvme_loop_complete_rq(struct request *req)
+{
+ struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
+ int error = 0;
+
+ nvme_cleanup_cmd(req);
+ sg_free_table_chained(&iod->sg_table, true);
+
+ if (unlikely(req->errors)) {
+ if (nvme_req_needs_retry(req, req->errors)) {
+ nvme_requeue_req(req);
+ return;
+ }
+
+ if (req->cmd_type == REQ_TYPE_DRV_PRIV)
+ error = req->errors;
+ else
+ error = nvme_error_status(req->errors);
+ }
+
+ blk_mq_end_request(req, error);
+}
+
+static void nvme_loop_queue_response(struct nvmet_req *nvme_req)
+{
+ struct nvme_loop_iod *iod =
+ container_of(nvme_req, struct nvme_loop_iod, req);
+ struct nvme_completion *cqe = &iod->rsp;
+
+ /*
+ * 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_loop_queue_idx(iod->queue) == 0 &&
+ cqe->command_id >= NVME_LOOP_AQ_BLKMQ_DEPTH)) {
+ nvme_complete_async_event(&iod->queue->ctrl->ctrl, cqe);
+ } else {
+ struct request *req = blk_mq_rq_from_pdu(iod);
+
+ if (req->cmd_type == REQ_TYPE_DRV_PRIV && req->special)
+ memcpy(req->special, cqe, sizeof(*cqe));
+ blk_mq_complete_request(req, le16_to_cpu(cqe->status) >> 1);
+ }
+}
+
+static void nvme_loop_execute_work(struct work_struct *work)
+{
+ struct nvme_loop_iod *iod =
+ container_of(work, struct nvme_loop_iod, work);
+
+ iod->req.execute(&iod->req);
+}
+
+static enum blk_eh_timer_return
+nvme_loop_timeout(struct request *rq, bool reserved)
+{
+ struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(rq);
+
+ /* queue error recovery */
+ schedule_work(&iod->queue->ctrl->reset_work);
+
+ /* fail with DNR on admin cmd timeout */
+ rq->errors = NVME_SC_ABORT_REQ | NVME_SC_DNR;
+
+ return BLK_EH_HANDLED;
+}
+
+static int nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct nvme_ns *ns = hctx->queue->queuedata;
+ struct nvme_loop_queue *queue = hctx->driver_data;
+ struct request *req = bd->rq;
+ struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
+ int ret;
+
+ ret = nvme_setup_cmd(ns, req, &iod->cmd);
+ if (ret)
+ return ret;
+
+ iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
+ iod->req.port = nvmet_loop_port;
+ if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
+ &queue->nvme_sq, &nvme_loop_ops)) {
+ nvme_cleanup_cmd(req);
+ blk_mq_start_request(req);
+ nvme_loop_queue_response(&iod->req);
+ return 0;
+ }
+
+ if (blk_rq_bytes(req)) {
+ iod->sg_table.sgl = iod->first_sgl;
+ ret = sg_alloc_table_chained(&iod->sg_table,
+ req->nr_phys_segments, iod->sg_table.sgl);
+ if (ret)
+ return BLK_MQ_RQ_QUEUE_BUSY;
+
+ iod->req.sg = iod->sg_table.sgl;
+ iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
+ BUG_ON(iod->req.sg_cnt > req->nr_phys_segments);
+ }
+
+ iod->cmd.common.command_id = req->tag;
+ blk_mq_start_request(req);
+
+ schedule_work(&iod->work);
+ return 0;
+}
+
+static void nvme_loop_submit_async_event(struct nvme_ctrl *arg, int aer_idx)
+{
+ struct nvme_loop_ctrl *ctrl = to_loop_ctrl(arg);
+ struct nvme_loop_queue *queue = &ctrl->queues[0];
+ struct nvme_loop_iod *iod = &ctrl->async_event_iod;
+
+ memset(&iod->cmd, 0, sizeof(iod->cmd));
+ iod->cmd.common.opcode = nvme_admin_async_event;
+ iod->cmd.common.command_id = NVME_LOOP_AQ_BLKMQ_DEPTH;
+
+ if (!nvmet_req_init(&iod->req, &queue->nvme_cq, &queue->nvme_sq,
+ &nvme_loop_ops)) {
+ dev_err(ctrl->ctrl.device, "failed async event work\n");
+ return;
+ }
+
+ schedule_work(&iod->work);
+}
+
+static int nvme_loop_init_iod(struct nvme_loop_ctrl *ctrl,
+ struct nvme_loop_iod *iod, unsigned int queue_idx)
+{
+ BUG_ON(queue_idx >= ctrl->queue_count);
+
+ iod->req.cmd = &iod->cmd;
+ iod->req.rsp = &iod->rsp;
+ iod->queue = &ctrl->queues[queue_idx];
+ INIT_WORK(&iod->work, nvme_loop_execute_work);
+ return 0;
+}
+
+static int nvme_loop_init_request(void *data, struct request *req,
+ unsigned int hctx_idx, unsigned int rq_idx,
+ unsigned int numa_node)
+{
+ return nvme_loop_init_iod(data, blk_mq_rq_to_pdu(req), hctx_idx + 1);
+}
+
+static int nvme_loop_init_admin_request(void *data, struct request *req,
+ unsigned int hctx_idx, unsigned int rq_idx,
+ unsigned int numa_node)
+{
+ return nvme_loop_init_iod(data, blk_mq_rq_to_pdu(req), 0);
+}
+
+static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+ unsigned int hctx_idx)
+{
+ struct nvme_loop_ctrl *ctrl = data;
+ struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
+
+ BUG_ON(hctx_idx >= ctrl->queue_count);
+
+ hctx->driver_data = queue;
+ return 0;
+}
+
+static int nvme_loop_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+ unsigned int hctx_idx)
+{
+ struct nvme_loop_ctrl *ctrl = data;
+ struct nvme_loop_queue *queue = &ctrl->queues[0];
+
+ BUG_ON(hctx_idx != 0);
+
+ hctx->driver_data = queue;
+ return 0;
+}
+
+static struct blk_mq_ops nvme_loop_mq_ops = {
+ .queue_rq = nvme_loop_queue_rq,
+ .complete = nvme_loop_complete_rq,
+ .map_queue = blk_mq_map_queue,
+ .init_request = nvme_loop_init_request,
+ .init_hctx = nvme_loop_init_hctx,
+ .timeout = nvme_loop_timeout,
+};
+
+static struct blk_mq_ops nvme_loop_admin_mq_ops = {
+ .queue_rq = nvme_loop_queue_rq,
+ .complete = nvme_loop_complete_rq,
+ .map_queue = blk_mq_map_queue,
+ .init_request = nvme_loop_init_admin_request,
+ .init_hctx = nvme_loop_init_admin_hctx,
+ .timeout = nvme_loop_timeout,
+};
+
+static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
+{
+ blk_cleanup_queue(ctrl->ctrl.admin_q);
+ blk_mq_free_tag_set(&ctrl->admin_tag_set);
+ nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
+}
+
+static void nvme_loop_free_ctrl(struct nvme_ctrl *nctrl)
+{
+ struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
+
+ if (list_empty(&ctrl->list))
+ goto free_ctrl;
+
+ mutex_lock(&nvme_loop_ctrl_mutex);
+ list_del(&ctrl->list);
+ mutex_unlock(&nvme_loop_ctrl_mutex);
+
+ if (nctrl->tagset) {
+ blk_cleanup_queue(ctrl->ctrl.connect_q);
+ blk_mq_free_tag_set(&ctrl->tag_set);
+ }
+ kfree(ctrl->queues);
+ nvmf_free_options(nctrl->opts);
+free_ctrl:
+ kfree(ctrl);
+}
+
+static int nvme_loop_configure_admin_queue(struct nvme_loop_ctrl *ctrl)
+{
+ int error;
+
+ memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
+ ctrl->admin_tag_set.ops = &nvme_loop_admin_mq_ops;
+ ctrl->admin_tag_set.queue_depth = NVME_LOOP_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_loop_iod) +
+ 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;
+
+ ctrl->queues[0].ctrl = ctrl;
+ error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
+ if (error)
+ return error;
+ ctrl->queue_count = 1;
+
+ error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
+ if (error)
+ goto out_free_sq;
+
+ 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 =
+ (NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
+
+ error = nvme_init_identify(&ctrl->ctrl);
+ if (error)
+ goto out_cleanup_queue;
+
+ nvme_start_keep_alive(&ctrl->ctrl);
+
+ 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_free_sq:
+ nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
+ return error;
+}
+
+static void nvme_loop_shutdown_ctrl(struct nvme_loop_ctrl *ctrl)
+{
+ int i;
+
+ nvme_stop_keep_alive(&ctrl->ctrl);
+
+ if (ctrl->queue_count > 1) {
+ nvme_stop_queues(&ctrl->ctrl);
+ blk_mq_tagset_busy_iter(&ctrl->tag_set,
+ nvme_cancel_request, &ctrl->ctrl);
+
+ for (i = 1; i < ctrl->queue_count; i++)
+ nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
+ }
+
+ 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_loop_destroy_admin_queue(ctrl);
+}
+
+static void nvme_loop_del_ctrl_work(struct work_struct *work)
+{
+ struct nvme_loop_ctrl *ctrl = container_of(work,
+ struct nvme_loop_ctrl, delete_work);
+
+ nvme_remove_namespaces(&ctrl->ctrl);
+ nvme_loop_shutdown_ctrl(ctrl);
+ nvme_uninit_ctrl(&ctrl->ctrl);
+ nvme_put_ctrl(&ctrl->ctrl);
+}
+
+static int __nvme_loop_del_ctrl(struct nvme_loop_ctrl *ctrl)
+{
+ if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING))
+ return -EBUSY;
+
+ if (!schedule_work(&ctrl->delete_work))
+ return -EBUSY;
+
+ return 0;
+}
+
+static int nvme_loop_del_ctrl(struct nvme_ctrl *nctrl)
+{
+ struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
+ int ret;
+
+ ret = __nvme_loop_del_ctrl(ctrl);
+ if (ret)
+ return ret;
+
+ flush_work(&ctrl->delete_work);
+
+ return 0;
+}
+
+static void nvme_loop_delete_ctrl(struct nvmet_ctrl *nctrl)
+{
+ struct nvme_loop_ctrl *ctrl;
+
+ mutex_lock(&nvme_loop_ctrl_mutex);
+ list_for_each_entry(ctrl, &nvme_loop_ctrl_list, list) {
+ if (ctrl->ctrl.cntlid == nctrl->cntlid)
+ __nvme_loop_del_ctrl(ctrl);
+ }
+ mutex_unlock(&nvme_loop_ctrl_mutex);
+}
+
+static void nvme_loop_reset_ctrl_work(struct work_struct *work)
+{
+ struct nvme_loop_ctrl *ctrl = container_of(work,
+ struct nvme_loop_ctrl, reset_work);
+ bool changed;
+ int i, ret;
+
+ nvme_loop_shutdown_ctrl(ctrl);
+
+ ret = nvme_loop_configure_admin_queue(ctrl);
+ if (ret)
+ goto out_disable;
+
+ for (i = 1; i <= ctrl->ctrl.opts->nr_io_queues; i++) {
+ ctrl->queues[i].ctrl = ctrl;
+ ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
+ if (ret)
+ goto out_free_queues;
+
+ ctrl->queue_count++;
+ }
+
+ for (i = 1; i <= ctrl->ctrl.opts->nr_io_queues; i++) {
+ ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
+ if (ret)
+ goto out_free_queues;
+ }
+
+ changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
+ WARN_ON_ONCE(!changed);
+
+ nvme_queue_scan(&ctrl->ctrl);
+ nvme_queue_async_events(&ctrl->ctrl);
+
+ nvme_start_queues(&ctrl->ctrl);
+
+ return;
+
+out_free_queues:
+ for (i = 1; i < ctrl->queue_count; i++)
+ nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
+ nvme_loop_destroy_admin_queue(ctrl);
+out_disable:
+ dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
+ nvme_remove_namespaces(&ctrl->ctrl);
+ nvme_uninit_ctrl(&ctrl->ctrl);
+ nvme_put_ctrl(&ctrl->ctrl);
+}
+
+static int nvme_loop_reset_ctrl(struct nvme_ctrl *nctrl)
+{
+ struct nvme_loop_ctrl *ctrl = to_loop_ctrl(nctrl);
+
+ if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING))
+ return -EBUSY;
+
+ if (!schedule_work(&ctrl->reset_work))
+ return -EBUSY;
+
+ flush_work(&ctrl->reset_work);
+
+ return 0;
+}
+
+static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
+ .name = "loop",
+ .module = THIS_MODULE,
+ .is_fabrics = true,
+ .reg_read32 = nvmf_reg_read32,
+ .reg_read64 = nvmf_reg_read64,
+ .reg_write32 = nvmf_reg_write32,
+ .reset_ctrl = nvme_loop_reset_ctrl,
+ .free_ctrl = nvme_loop_free_ctrl,
+ .submit_async_event = nvme_loop_submit_async_event,
+ .delete_ctrl = nvme_loop_del_ctrl,
+ .get_subsysnqn = nvmf_get_subsysnqn,
+};
+
+static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
+{
+ struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
+ int ret, i;
+
+ ret = nvme_set_queue_count(&ctrl->ctrl, &opts->nr_io_queues);
+ if (ret || !opts->nr_io_queues)
+ return ret;
+
+ dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n",
+ opts->nr_io_queues);
+
+ for (i = 1; i <= opts->nr_io_queues; i++) {
+ ctrl->queues[i].ctrl = ctrl;
+ ret = nvmet_sq_init(&ctrl->queues[i].nvme_sq);
+ if (ret)
+ goto out_destroy_queues;
+
+ ctrl->queue_count++;
+ }
+
+ memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
+ ctrl->tag_set.ops = &nvme_loop_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_loop_iod) +
+ 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;
+ ctrl->ctrl.tagset = &ctrl->tag_set;
+
+ ret = blk_mq_alloc_tag_set(&ctrl->tag_set);
+ if (ret)
+ goto out_destroy_queues;
+
+ ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
+ if (IS_ERR(ctrl->ctrl.connect_q)) {
+ ret = PTR_ERR(ctrl->ctrl.connect_q);
+ goto out_free_tagset;
+ }
+
+ for (i = 1; i <= opts->nr_io_queues; i++) {
+ ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
+ if (ret)
+ goto out_cleanup_connect_q;
+ }
+
+ return 0;
+
+out_cleanup_connect_q:
+ blk_cleanup_queue(ctrl->ctrl.connect_q);
+out_free_tagset:
+ blk_mq_free_tag_set(&ctrl->tag_set);
+out_destroy_queues:
+ for (i = 1; i < ctrl->queue_count; i++)
+ nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
+ return ret;
+}
+
+static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
+ struct nvmf_ctrl_options *opts)
+{
+ struct nvme_loop_ctrl *ctrl;
+ bool changed;
+ int ret;
+
+ ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl)
+ return ERR_PTR(-ENOMEM);
+ ctrl->ctrl.opts = opts;
+ INIT_LIST_HEAD(&ctrl->list);
+
+ INIT_WORK(&ctrl->delete_work, nvme_loop_del_ctrl_work);
+ INIT_WORK(&ctrl->reset_work, nvme_loop_reset_ctrl_work);
+
+ ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_loop_ctrl_ops,
+ 0 /* no quirks, we're perfect! */);
+ if (ret)
+ goto out_put_ctrl;
+
+ spin_lock_init(&ctrl->lock);
+
+ ret = -ENOMEM;
+
+ ctrl->ctrl.sqsize = opts->queue_size;
+ ctrl->ctrl.kato = opts->kato;
+
+ ctrl->queues = kcalloc(opts->nr_io_queues + 1, sizeof(*ctrl->queues),
+ GFP_KERNEL);
+ if (!ctrl->queues)
+ goto out_uninit_ctrl;
+
+ ret = nvme_loop_configure_admin_queue(ctrl);
+ if (ret)
+ goto out_free_queues;
+
+ 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_loop_create_io_queues(ctrl);
+ if (ret)
+ goto out_remove_admin_queue;
+ }
+
+ nvme_loop_init_iod(ctrl, &ctrl->async_event_iod, 0);
+
+ dev_info(ctrl->ctrl.device,
+ "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn);
+
+ kref_get(&ctrl->ctrl.kref);
+
+ changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
+ WARN_ON_ONCE(!changed);
+
+ mutex_lock(&nvme_loop_ctrl_mutex);
+ list_add_tail(&ctrl->list, &nvme_loop_ctrl_list);
+ mutex_unlock(&nvme_loop_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_loop_destroy_admin_queue(ctrl);
+out_free_queues:
+ kfree(ctrl->queues);
+out_uninit_ctrl:
+ nvme_uninit_ctrl(&ctrl->ctrl);
+out_put_ctrl:
+ nvme_put_ctrl(&ctrl->ctrl);
+ if (ret > 0)
+ ret = -EIO;
+ return ERR_PTR(ret);
+}
+
+static int nvme_loop_add_port(struct nvmet_port *port)
+{
+ /*
+ * XXX: disalow adding more than one port so
+ * there is no connection rejections when a
+ * a subsystem is assigned to a port for which
+ * loop doesn't have a pointer.
+ * This scenario would be possible if we allowed
+ * more than one port to be added and a subsystem
+ * was assigned to a port other than nvmet_loop_port.
+ */
+
+ if (nvmet_loop_port)
+ return -EPERM;
+
+ nvmet_loop_port = port;
+ return 0;
+}
+
+static void nvme_loop_remove_port(struct nvmet_port *port)
+{
+ if (port == nvmet_loop_port)
+ nvmet_loop_port = NULL;
+}
+
+static struct nvmet_fabrics_ops nvme_loop_ops = {
+ .owner = THIS_MODULE,
+ .type = NVMF_TRTYPE_LOOP,
+ .add_port = nvme_loop_add_port,
+ .remove_port = nvme_loop_remove_port,
+ .queue_response = nvme_loop_queue_response,
+ .delete_ctrl = nvme_loop_delete_ctrl,
+};
+
+static struct nvmf_transport_ops nvme_loop_transport = {
+ .name = "loop",
+ .create_ctrl = nvme_loop_create_ctrl,
+};
+
+static int __init nvme_loop_init_module(void)
+{
+ int ret;
+
+ ret = nvmet_register_transport(&nvme_loop_ops);
+ if (ret)
+ return ret;
+ nvmf_register_transport(&nvme_loop_transport);
+ return 0;
+}
+
+static void __exit nvme_loop_cleanup_module(void)
+{
+ struct nvme_loop_ctrl *ctrl, *next;
+
+ nvmf_unregister_transport(&nvme_loop_transport);
+ nvmet_unregister_transport(&nvme_loop_ops);
+
+ mutex_lock(&nvme_loop_ctrl_mutex);
+ list_for_each_entry_safe(ctrl, next, &nvme_loop_ctrl_list, list)
+ __nvme_loop_del_ctrl(ctrl);
+ mutex_unlock(&nvme_loop_ctrl_mutex);
+
+ flush_scheduled_work();
+}
+
+module_init(nvme_loop_init_module);
+module_exit(nvme_loop_cleanup_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("nvmet-transport-254"); /* 254 == NVMF_TRTYPE_LOOP */
--
2.1.4
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