blob: f2d24b2d992f8721609b59414a4b5beafa33d0ad [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* NVMe over Fabrics loopback device.
* Copyright (c) 2015-2016 HGST, a Western Digital Company.
*/
#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 cqe;
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_port *port;
};
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 LIST_HEAD(nvme_loop_ports);
static DEFINE_MUTEX(nvme_loop_ports_mutex);
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);
sg_free_table_chained(&iod->sg_table, NVME_INLINE_SG_CNT);
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->cqe;
/*
* 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_is_aen_req(nvme_loop_queue_idx(queue),
cqe->command_id))) {
nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
&cqe->result);
} else {
struct request *rq;
rq = nvme_find_rq(nvme_loop_tagset(queue), cqe->command_id);
if (!rq) {
dev_err(queue->ctrl->ctrl.device,
"got bad command_id %#x on queue %d\n",
cqe->command_id, nvme_loop_queue_idx(queue));
return;
}
if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
nvme_loop_complete_rq(rq);
}
}
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 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);
bool queue_ready = test_bit(NVME_LOOP_Q_LIVE, &queue->flags);
blk_status_t ret;
if (!nvme_check_ready(&queue->ctrl->ctrl, req, queue_ready))
return nvme_fail_nonready_command(&queue->ctrl->ctrl, req);
ret = nvme_setup_cmd(ns, req);
if (ret)
return ret;
nvme_start_request(req);
iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
iod->req.port = queue->ctrl->port;
if (!nvmet_req_init(&iod->req, &queue->nvme_cq,
&queue->nvme_sq, &nvme_loop_ops))
return BLK_STS_OK;
if (blk_rq_nr_phys_segments(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, NVME_INLINE_SG_CNT)) {
nvme_cleanup_cmd(req);
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);
}
queue_work(nvmet_wq, &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;
}
queue_work(nvmet_wq, &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.cqe = &iod->cqe;
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 = to_loop_ctrl(set->driver_data);
struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
nvme_req(req)->ctrl = &ctrl->ctrl;
nvme_req(req)->cmd = &iod->cmd;
return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
(set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
}
static struct lock_class_key loop_hctx_fq_lock_key;
static int nvme_loop_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
unsigned int hctx_idx)
{
struct nvme_loop_ctrl *ctrl = to_loop_ctrl(data);
struct nvme_loop_queue *queue = &ctrl->queues[hctx_idx + 1];
BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);
/*
* flush_end_io() can be called recursively for us, so use our own
* lock class key for avoiding lockdep possible recursive locking,
* then we can remove the dynamically allocated lock class for each
* flush queue, that way may cause horrible boot delay.
*/
blk_mq_hctx_set_fq_lock_class(hctx, &loop_hctx_fq_lock_key);
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 = to_loop_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,
};
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,
};
static void nvme_loop_destroy_admin_queue(struct nvme_loop_ctrl *ctrl)
{
if (!test_and_clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags))
return;
nvmet_sq_destroy(&ctrl->queues[0].nvme_sq);
nvme_remove_admin_tag_set(&ctrl->ctrl);
}
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)
nvme_remove_io_tag_set(nctrl);
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);
}
ctrl->ctrl.queue_count = 1;
}
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;
ctrl->queues[0].ctrl = ctrl;
error = nvmet_sq_init(&ctrl->queues[0].nvme_sq);
if (error)
return error;
ctrl->ctrl.queue_count = 1;
error = nvme_alloc_admin_tag_set(&ctrl->ctrl, &ctrl->admin_tag_set,
&nvme_loop_admin_mq_ops,
sizeof(struct nvme_loop_iod) +
NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
if (error)
goto out_free_sq;
/* reset stopped state for the fresh admin queue */
clear_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->ctrl.flags);
error = nvmf_connect_admin_queue(&ctrl->ctrl);
if (error)
goto out_cleanup_tagset;
set_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
error = nvme_enable_ctrl(&ctrl->ctrl);
if (error)
goto out_cleanup_tagset;
ctrl->ctrl.max_hw_sectors =
(NVME_LOOP_MAX_SEGMENTS - 1) << (PAGE_SHIFT - 9);
nvme_unquiesce_admin_queue(&ctrl->ctrl);
error = nvme_init_ctrl_finish(&ctrl->ctrl, false);
if (error)
goto out_cleanup_tagset;
return 0;
out_cleanup_tagset:
clear_bit(NVME_LOOP_Q_LIVE, &ctrl->queues[0].flags);
nvme_remove_admin_tag_set(&ctrl->ctrl);
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_quiesce_io_queues(&ctrl->ctrl);
nvme_cancel_tagset(&ctrl->ctrl);
nvme_loop_destroy_io_queues(ctrl);
}
nvme_quiesce_admin_queue(&ctrl->ctrl);
if (ctrl->ctrl.state == NVME_CTRL_LIVE)
nvme_disable_ctrl(&ctrl->ctrl, true);
nvme_cancel_admin_tagset(&ctrl->ctrl);
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);
int ret;
nvme_stop_ctrl(&ctrl->ctrl);
nvme_loop_shutdown_ctrl(ctrl);
if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
if (ctrl->ctrl.state != NVME_CTRL_DELETING &&
ctrl->ctrl.state != NVME_CTRL_DELETING_NOIO)
/* state change failure for non-deleted ctrl? */
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);
if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
WARN_ON_ONCE(1);
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);
}
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,
.get_address = nvmf_get_address,
};
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;
ret = nvme_alloc_io_tag_set(&ctrl->ctrl, &ctrl->tag_set,
&nvme_loop_mq_ops, 1,
sizeof(struct nvme_loop_iod) +
NVME_INLINE_SG_CNT * sizeof(struct scatterlist));
if (ret)
goto out_destroy_queues;
ret = nvme_loop_connect_io_queues(ctrl);
if (ret)
goto out_cleanup_tagset;
return 0;
out_cleanup_tagset:
nvme_remove_io_tag_set(&ctrl->ctrl);
out_destroy_queues:
nvme_loop_destroy_io_queues(ctrl);
return ret;
}
static struct nvmet_port *nvme_loop_find_port(struct nvme_ctrl *ctrl)
{
struct nvmet_port *p, *found = NULL;
mutex_lock(&nvme_loop_ports_mutex);
list_for_each_entry(p, &nvme_loop_ports, entry) {
/* if no transport address is specified use the first port */
if ((ctrl->opts->mask & NVMF_OPT_TRADDR) &&
strcmp(ctrl->opts->traddr, p->disc_addr.traddr))
continue;
found = p;
break;
}
mutex_unlock(&nvme_loop_ports_mutex);
return found;
}
static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev,
struct nvmf_ctrl_options *opts)
{
struct nvme_loop_ctrl *ctrl;
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) {
kfree(ctrl);
goto out;
}
if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
WARN_ON_ONCE(1);
ret = -ENOMEM;
ctrl->ctrl.kato = opts->kato;
ctrl->port = nvme_loop_find_port(&ctrl->ctrl);
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;
}
ctrl->ctrl.sqsize = opts->queue_size - 1;
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);
if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
WARN_ON_ONCE(1);
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);
nvme_put_ctrl(&ctrl->ctrl);
out:
if (ret > 0)
ret = -EIO;
return ERR_PTR(ret);
}
static int nvme_loop_add_port(struct nvmet_port *port)
{
mutex_lock(&nvme_loop_ports_mutex);
list_add_tail(&port->entry, &nvme_loop_ports);
mutex_unlock(&nvme_loop_ports_mutex);
return 0;
}
static void nvme_loop_remove_port(struct nvmet_port *port)
{
mutex_lock(&nvme_loop_ports_mutex);
list_del_init(&port->entry);
mutex_unlock(&nvme_loop_ports_mutex);
/*
* Ensure any ctrls that are in the process of being
* deleted are in fact deleted before we return
* and free the port. This is to prevent active
* ctrls from using a port after it's freed.
*/
flush_workqueue(nvme_delete_wq);
}
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,
.allowed_opts = NVMF_OPT_TRADDR,
};
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 */