diff options
Diffstat (limited to 'drivers/nvme/target/loop.c')
| -rw-r--r-- | drivers/nvme/target/loop.c | 688 |
1 files changed, 688 insertions, 0 deletions
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c new file mode 100644 index 000000000..c864e902e --- /dev/null +++ b/drivers/nvme/target/loop.c @@ -0,0 +1,688 @@ +// 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; + + blk_mq_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_start_admin_queue(&ctrl->ctrl); + + error = nvme_init_ctrl_finish(&ctrl->ctrl); + 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_stop_queues(&ctrl->ctrl); + nvme_cancel_tagset(&ctrl->ctrl); + nvme_loop_destroy_io_queues(ctrl); + } + + nvme_stop_admin_queue(&ctrl->ctrl); + if (ctrl->ctrl.state == NVME_CTRL_LIVE) + nvme_shutdown_ctrl(&ctrl->ctrl); + + 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 */ |