blob: 27a8561c0cb97596d25b53620493978040082124 [file] [log] [blame]
/*
* 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/blk-mq.h>
#include <linux/nvme.h>
#include <linux/module.h>
#include <linux/parser.h>
#include "nvmet.h"
#include "../host/nvme.h"
#include "../host/fabrics.h"
#define NVME_LOOP_MAX_SEGMENTS 256
struct nvme_loop_iod {
struct nvme_request nvme_req;
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 {
struct nvme_loop_queue *queues;
struct blk_mq_tag_set admin_tag_set;
struct list_head list;
struct blk_mq_tag_set tag_set;
struct nvme_loop_iod async_event_iod;
struct nvme_ctrl ctrl;
struct nvmet_ctrl *target_ctrl;
};
static inline struct nvme_loop_ctrl *to_loop_ctrl(struct nvme_ctrl *ctrl)
{
return container_of(ctrl, struct nvme_loop_ctrl, ctrl);
}
enum nvme_loop_queue_flags {
NVME_LOOP_Q_LIVE = 0,
};
struct nvme_loop_queue {
struct nvmet_cq nvme_cq;
struct nvmet_sq nvme_sq;
struct nvme_loop_ctrl *ctrl;
unsigned long flags;
};
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 const 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);
nvme_cleanup_cmd(req);
sg_free_table_chained(&iod->sg_table, true);
nvme_complete_rq(req);
}
static struct blk_mq_tags *nvme_loop_tagset(struct nvme_loop_queue *queue)
{
u32 queue_idx = nvme_loop_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_loop_queue_response(struct nvmet_req *req)
{
struct nvme_loop_queue *queue =
container_of(req->sq, struct nvme_loop_queue, nvme_sq);
struct nvme_completion *cqe = req->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(queue) == 0 &&
cqe->command_id >= NVME_AQ_BLK_MQ_DEPTH)) {
nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
&cqe->result);
} else {
struct request *rq;
rq = blk_mq_tag_to_rq(nvme_loop_tagset(queue), cqe->command_id);
if (!rq) {
dev_err(queue->ctrl->ctrl.device,
"tag 0x%x on queue %d not found\n",
cqe->command_id, nvme_loop_queue_idx(queue));
return;
}
nvme_end_request(rq, cqe->status, cqe->result);
}
}
static void nvme_loop_execute_work(struct work_struct *work)
{
struct nvme_loop_iod *iod =
container_of(work, struct nvme_loop_iod, work);
nvmet_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 */
nvme_reset_ctrl(&iod->queue->ctrl->ctrl);
/* fail with DNR on admin cmd timeout */
nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
return BLK_EH_HANDLED;
}
static blk_status_t 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);
blk_status_t ret;
ret = nvmf_check_if_ready(&queue->ctrl->ctrl, req,
test_bit(NVME_LOOP_Q_LIVE, &queue->flags), true);
if (unlikely(ret))
return ret;
ret = nvme_setup_cmd(ns, req, &iod->cmd);
if (ret)
return ret;
blk_mq_start_request(req);
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))
return BLK_STS_OK;
if (blk_rq_payload_bytes(req)) {
iod->sg_table.sgl = iod->first_sgl;
if (sg_alloc_table_chained(&iod->sg_table,
blk_rq_nr_phys_segments(req),
iod->sg_table.sgl))
return BLK_STS_RESOURCE;
iod->req.sg = iod->sg_table.sgl;
iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl);
iod->req.transfer_len = blk_rq_payload_bytes(req);
}
schedule_work(&iod->work);
return BLK_STS_OK;
}
static void nvme_loop_submit_async_event(struct nvme_ctrl *arg)
{
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_AQ_BLK_MQ_DEPTH;
iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
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)
{
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(struct blk_mq_tag_set *set,
struct request *req, unsigned int hctx_idx,
unsigned int numa_node)
{
struct nvme_loop_ctrl *ctrl = set->driver_data;
return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
(set == &ctrl->tag_set) ? hctx_idx + 1 : 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->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 const struct blk_mq_ops nvme_loop_mq_ops = {
.queue_rq = nvme_loop_queue_rq,
.complete = nvme_loop_complete_rq,
.init_request = nvme_loop_init_request,
.init_hctx = nvme_loop_init_hctx,
.timeout = nvme_loop_timeout,
};
static const struct blk_mq_ops nvme_loop_admin_mq_ops = {
.queue_rq = nvme_loop_queue_rq,
.complete = nvme_loop_complete_rq,
.init_request = nvme_loop_init_request,
.init_hctx = nvme_loop_init_admin_hctx,
.timeout = nvme_loop_timeout,
};
static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
{
clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
blk_cleanup_queue(ctrl->ctrl.admin_q);
blk_mq_free_tag_set(&ctrl->admin_tag_set);
}
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 void nvme_loop_destroy_io_queues(struct nvme_loop_ctrl *ctrl)
{
int i;
for (i = 1; i < ctrl->ctrl.queue_count; i++) {
clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
nvmet_sq_destroy(&ctrl->queues[i].nvme_sq);
}
}
static int nvme_loop_init_io_queues(struct nvme_loop_ctrl *ctrl)
{
struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
unsigned int nr_io_queues;
int ret, i;
nr_io_queues = min(opts->nr_io_queues, num_online_cpus());
ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
if (ret || !nr_io_queues)
return ret;
dev_info(ctrl->ctrl.device, "creating %d I/O queues.\n", nr_io_queues);
for (i = 1; i <= 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->ctrl.queue_count++;
}
return 0;
out_destroy_queues:
nvme_loop_destroy_io_queues(ctrl);
return ret;
}
static int nvme_loop_connect_io_queues(struct nvme_loop_ctrl *ctrl)
{
int i, ret;
for (i = 1; i < ctrl->ctrl.queue_count; i++) {
ret = nvmf_connect_io_queue(&ctrl->ctrl, i);
if (ret)
return ret;
set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[i].flags);
}
return 0;
}
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_AQ_MQ_TAG_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->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
ctrl->queues[0].ctrl = ctrl;
error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
if (error)
return error;
ctrl->ctrl.queue_count = 1;
error = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
if (error)
goto out_free_sq;
ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
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;
set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
error = nvmf_reg_read64(&ctrl->ctrl, NVME_REG_CAP, &ctrl->ctrl.cap);
if (error) {
dev_err(ctrl->ctrl.device,
"prop_get NVME_REG_CAP failed\n");
goto out_cleanup_queue;
}
ctrl->ctrl.sqsize =
min_t(int, NVME_CAP_MQES(ctrl->ctrl.cap), ctrl->ctrl.sqsize);
error = nvme_enable_ctrl(&ctrl->ctrl, ctrl->ctrl.cap);
if (error)
goto out_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;
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)
{
if (ctrl->ctrl.queue_count > 1) {
nvme_stop_queues(&ctrl->ctrl);
blk_mq_tagset_busy_iter(&ctrl->tag_set,
nvme_cancel_request, &ctrl->ctrl);
nvme_loop_destroy_io_queues(ctrl);
}
if (ctrl->ctrl.state == NVME_CTRL_LIVE)
nvme_shutdown_ctrl(&ctrl->ctrl);
blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
nvme_cancel_request, &ctrl->ctrl);
blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
nvme_loop_destroy_admin_queue(ctrl);
}
static void nvme_loop_delete_ctrl_host(struct nvme_ctrl *ctrl)
{
nvme_loop_shutdown_ctrl(to_loop_ctrl(ctrl));
}
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_delete_ctrl(&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, ctrl.reset_work);
bool changed;
int ret;
nvme_stop_ctrl(&ctrl->ctrl);
nvme_loop_shutdown_ctrl(ctrl);
if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
/* state change failure should never happen */
WARN_ON_ONCE(1);
return;
}
ret = nvme_loop_configure_admin_queue(ctrl);
if (ret)
goto out_disable;
ret = nvme_loop_init_io_queues(ctrl);
if (ret)
goto out_destroy_admin;
ret = nvme_loop_connect_io_queues(ctrl);
if (ret)
goto out_destroy_io;
blk_mq_update_nr_hw_queues(&ctrl->tag_set,
ctrl->ctrl.queue_count - 1);
changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
WARN_ON_ONCE(!changed);
nvme_start_ctrl(&ctrl->ctrl);
return;
out_destroy_io:
nvme_loop_destroy_io_queues(ctrl);
out_destroy_admin:
nvme_loop_destroy_admin_queue(ctrl);
out_disable:
dev_warn(ctrl->ctrl.device, "Removing after reset failure\n");
nvme_uninit_ctrl(&ctrl->ctrl);
nvme_put_ctrl(&ctrl->ctrl);
}
static const struct nvme_ctrl_ops nvme_loop_ctrl_ops = {
.name = "loop",
.module = THIS_MODULE,
.flags = NVME_F_FABRICS,
.reg_read32 = nvmf_reg_read32,
.reg_read64 = nvmf_reg_read64,
.reg_write32 = nvmf_reg_write32,
.free_ctrl = nvme_loop_free_ctrl,
.submit_async_event = nvme_loop_submit_async_event,
.delete_ctrl = nvme_loop_delete_ctrl_host,
};
static int nvme_loop_create_io_queues(struct nvme_loop_ctrl *ctrl)
{
int ret;
ret = nvme_loop_init_io_queues(ctrl);
if (ret)
return ret;
memset(&ctrl->tag_set, 0, sizeof(ctrl->tag_set));
ctrl->tag_set.ops = &nvme_loop_mq_ops;
ctrl->tag_set.queue_depth = ctrl->ctrl.opts->queue_size;
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->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;
}
ret = nvme_loop_connect_io_queues(ctrl);
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:
nvme_loop_destroy_io_queues(ctrl);
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->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;
ret = -ENOMEM;
ctrl->ctrl.sqsize = opts->queue_size - 1;
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);
nvme_get_ctrl(&ctrl->ctrl);
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);
nvme_start_ctrl(&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 const 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",
.module = THIS_MODULE,
.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;
ret = nvmf_register_transport(&nvme_loop_transport);
if (ret)
nvmet_unregister_transport(&nvme_loop_ops);
return ret;
}
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_delete_ctrl(&ctrl->ctrl);
mutex_unlock(&nvme_loop_ctrl_mutex);
flush_workqueue(nvme_delete_wq);
}
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 */