core.c 29.1 KB
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/*
 * Common code for the NVMe 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/module.h>
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#include <linux/random.h>
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#include <linux/rculist.h>

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#include "nvmet.h"

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struct workqueue_struct *buffered_io_wq;
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static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
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static DEFINE_IDA(cntlid_ida);
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/*
 * This read/write semaphore is used to synchronize access to configuration
 * information on a target system that will result in discovery log page
 * information change for at least one host.
 * The full list of resources to protected by this semaphore is:
 *
 *  - subsystems list
 *  - per-subsystem allowed hosts list
 *  - allow_any_host subsystem attribute
 *  - nvmet_genctr
 *  - the nvmet_transports array
 *
 * When updating any of those lists/structures write lock should be obtained,
 * while when reading (popolating discovery log page or checking host-subsystem
 * link) read lock is obtained to allow concurrent reads.
 */
DECLARE_RWSEM(nvmet_config_sem);

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u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
u64 nvmet_ana_chgcnt;
DECLARE_RWSEM(nvmet_ana_sem);

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static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
		const char *subsysnqn);

u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
		size_t len)
{
	if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
		return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
	return 0;
}

u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)
{
	if (sg_pcopy_to_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
		return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
	return 0;
}

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u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len)
{
	if (sg_zero_buffer(req->sg, req->sg_cnt, len, off) != len)
		return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
	return 0;
}

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static unsigned int nvmet_max_nsid(struct nvmet_subsys *subsys)
{
	struct nvmet_ns *ns;

	if (list_empty(&subsys->namespaces))
		return 0;

	ns = list_last_entry(&subsys->namespaces, struct nvmet_ns, dev_link);
	return ns->nsid;
}

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static u32 nvmet_async_event_result(struct nvmet_async_event *aen)
{
	return aen->event_type | (aen->event_info << 8) | (aen->log_page << 16);
}

static void nvmet_async_events_free(struct nvmet_ctrl *ctrl)
{
	struct nvmet_req *req;

	while (1) {
		mutex_lock(&ctrl->lock);
		if (!ctrl->nr_async_event_cmds) {
			mutex_unlock(&ctrl->lock);
			return;
		}

		req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
		mutex_unlock(&ctrl->lock);
		nvmet_req_complete(req, NVME_SC_INTERNAL | NVME_SC_DNR);
	}
}

static void nvmet_async_event_work(struct work_struct *work)
{
	struct nvmet_ctrl *ctrl =
		container_of(work, struct nvmet_ctrl, async_event_work);
	struct nvmet_async_event *aen;
	struct nvmet_req *req;

	while (1) {
		mutex_lock(&ctrl->lock);
		aen = list_first_entry_or_null(&ctrl->async_events,
				struct nvmet_async_event, entry);
		if (!aen || !ctrl->nr_async_event_cmds) {
			mutex_unlock(&ctrl->lock);
			return;
		}

		req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
		nvmet_set_result(req, nvmet_async_event_result(aen));

		list_del(&aen->entry);
		kfree(aen);

		mutex_unlock(&ctrl->lock);
		nvmet_req_complete(req, 0);
	}
}

static void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
		u8 event_info, u8 log_page)
{
	struct nvmet_async_event *aen;

	aen = kmalloc(sizeof(*aen), GFP_KERNEL);
	if (!aen)
		return;

	aen->event_type = event_type;
	aen->event_info = event_info;
	aen->log_page = log_page;

	mutex_lock(&ctrl->lock);
	list_add_tail(&aen->entry, &ctrl->async_events);
	mutex_unlock(&ctrl->lock);

	schedule_work(&ctrl->async_event_work);
}

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static bool nvmet_aen_disabled(struct nvmet_ctrl *ctrl, u32 aen)
{
	if (!(READ_ONCE(ctrl->aen_enabled) & aen))
		return true;
	return test_and_set_bit(aen, &ctrl->aen_masked);
}

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static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
{
	u32 i;

	mutex_lock(&ctrl->lock);
	if (ctrl->nr_changed_ns > NVME_MAX_CHANGED_NAMESPACES)
		goto out_unlock;

	for (i = 0; i < ctrl->nr_changed_ns; i++) {
		if (ctrl->changed_ns_list[i] == nsid)
			goto out_unlock;
	}

	if (ctrl->nr_changed_ns == NVME_MAX_CHANGED_NAMESPACES) {
		ctrl->changed_ns_list[0] = cpu_to_le32(0xffffffff);
		ctrl->nr_changed_ns = U32_MAX;
		goto out_unlock;
	}

	ctrl->changed_ns_list[ctrl->nr_changed_ns++] = nsid;
out_unlock:
	mutex_unlock(&ctrl->lock);
}

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void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
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{
	struct nvmet_ctrl *ctrl;

	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
		nvmet_add_to_changed_ns_log(ctrl, cpu_to_le32(nsid));
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		if (nvmet_aen_disabled(ctrl, NVME_AEN_CFG_NS_ATTR))
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			continue;
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		nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
				NVME_AER_NOTICE_NS_CHANGED,
				NVME_LOG_CHANGED_NS);
	}
}

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void nvmet_send_ana_event(struct nvmet_subsys *subsys,
		struct nvmet_port *port)
{
	struct nvmet_ctrl *ctrl;

	mutex_lock(&subsys->lock);
	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
		if (port && ctrl->port != port)
			continue;
		if (nvmet_aen_disabled(ctrl, NVME_AEN_CFG_ANA_CHANGE))
			continue;
		nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
				NVME_AER_NOTICE_ANA, NVME_LOG_ANA);
	}
	mutex_unlock(&subsys->lock);
}

void nvmet_port_send_ana_event(struct nvmet_port *port)
{
	struct nvmet_subsys_link *p;

	down_read(&nvmet_config_sem);
	list_for_each_entry(p, &port->subsystems, entry)
		nvmet_send_ana_event(p->subsys, port);
	up_read(&nvmet_config_sem);
}

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int nvmet_register_transport(const struct nvmet_fabrics_ops *ops)
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{
	int ret = 0;

	down_write(&nvmet_config_sem);
	if (nvmet_transports[ops->type])
		ret = -EINVAL;
	else
		nvmet_transports[ops->type] = ops;
	up_write(&nvmet_config_sem);

	return ret;
}
EXPORT_SYMBOL_GPL(nvmet_register_transport);

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void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
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{
	down_write(&nvmet_config_sem);
	nvmet_transports[ops->type] = NULL;
	up_write(&nvmet_config_sem);
}
EXPORT_SYMBOL_GPL(nvmet_unregister_transport);

int nvmet_enable_port(struct nvmet_port *port)
{
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	const struct nvmet_fabrics_ops *ops;
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	int ret;

	lockdep_assert_held(&nvmet_config_sem);

	ops = nvmet_transports[port->disc_addr.trtype];
	if (!ops) {
		up_write(&nvmet_config_sem);
		request_module("nvmet-transport-%d", port->disc_addr.trtype);
		down_write(&nvmet_config_sem);
		ops = nvmet_transports[port->disc_addr.trtype];
		if (!ops) {
			pr_err("transport type %d not supported\n",
				port->disc_addr.trtype);
			return -EINVAL;
		}
	}

	if (!try_module_get(ops->owner))
		return -EINVAL;

	ret = ops->add_port(port);
	if (ret) {
		module_put(ops->owner);
		return ret;
	}

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	/* If the transport didn't set inline_data_size, then disable it. */
	if (port->inline_data_size < 0)
		port->inline_data_size = 0;

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	port->enabled = true;
	return 0;
}

void nvmet_disable_port(struct nvmet_port *port)
{
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	const struct nvmet_fabrics_ops *ops;
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	lockdep_assert_held(&nvmet_config_sem);

	port->enabled = false;

	ops = nvmet_transports[port->disc_addr.trtype];
	ops->remove_port(port);
	module_put(ops->owner);
}

static void nvmet_keep_alive_timer(struct work_struct *work)
{
	struct nvmet_ctrl *ctrl = container_of(to_delayed_work(work),
			struct nvmet_ctrl, ka_work);

	pr_err("ctrl %d keep-alive timer (%d seconds) expired!\n",
		ctrl->cntlid, ctrl->kato);

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	nvmet_ctrl_fatal_error(ctrl);
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}

static void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
{
	pr_debug("ctrl %d start keep-alive timer for %d secs\n",
		ctrl->cntlid, ctrl->kato);

	INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
	schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
}

static void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
{
	pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);

	cancel_delayed_work_sync(&ctrl->ka_work);
}

static struct nvmet_ns *__nvmet_find_namespace(struct nvmet_ctrl *ctrl,
		__le32 nsid)
{
	struct nvmet_ns *ns;

	list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
		if (ns->nsid == le32_to_cpu(nsid))
			return ns;
	}

	return NULL;
}

struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid)
{
	struct nvmet_ns *ns;

	rcu_read_lock();
	ns = __nvmet_find_namespace(ctrl, nsid);
	if (ns)
		percpu_ref_get(&ns->ref);
	rcu_read_unlock();

	return ns;
}

static void nvmet_destroy_namespace(struct percpu_ref *ref)
{
	struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);

	complete(&ns->disable_done);
}

void nvmet_put_namespace(struct nvmet_ns *ns)
{
	percpu_ref_put(&ns->ref);
}

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static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
{
	nvmet_bdev_ns_disable(ns);
	nvmet_file_ns_disable(ns);
}

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int nvmet_ns_enable(struct nvmet_ns *ns)
{
	struct nvmet_subsys *subsys = ns->subsys;
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	int ret;
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	mutex_lock(&subsys->lock);
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	ret = -EMFILE;
	if (subsys->nr_namespaces == NVMET_MAX_NAMESPACES)
		goto out_unlock;
	ret = 0;
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	if (ns->enabled)
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		goto out_unlock;

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	ret = nvmet_bdev_ns_enable(ns);
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	if (ret == -ENOTBLK)
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		ret = nvmet_file_ns_enable(ns);
	if (ret)
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		goto out_unlock;

	ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
				0, GFP_KERNEL);
	if (ret)
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		goto out_dev_put;
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	if (ns->nsid > subsys->max_nsid)
		subsys->max_nsid = ns->nsid;

	/*
	 * The namespaces list needs to be sorted to simplify the implementation
	 * of the Identify Namepace List subcommand.
	 */
	if (list_empty(&subsys->namespaces)) {
		list_add_tail_rcu(&ns->dev_link, &subsys->namespaces);
	} else {
		struct nvmet_ns *old;

		list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) {
			BUG_ON(ns->nsid == old->nsid);
			if (ns->nsid < old->nsid)
				break;
		}

		list_add_tail_rcu(&ns->dev_link, &old->dev_link);
	}
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	subsys->nr_namespaces++;
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	nvmet_ns_changed(subsys, ns->nsid);
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	ns->enabled = true;
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	ret = 0;
out_unlock:
	mutex_unlock(&subsys->lock);
	return ret;
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out_dev_put:
	nvmet_ns_dev_disable(ns);
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	goto out_unlock;
}

void nvmet_ns_disable(struct nvmet_ns *ns)
{
	struct nvmet_subsys *subsys = ns->subsys;

	mutex_lock(&subsys->lock);
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	if (!ns->enabled)
		goto out_unlock;

	ns->enabled = false;
	list_del_rcu(&ns->dev_link);
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	if (ns->nsid == subsys->max_nsid)
		subsys->max_nsid = nvmet_max_nsid(subsys);
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	mutex_unlock(&subsys->lock);

	/*
	 * Now that we removed the namespaces from the lookup list, we
	 * can kill the per_cpu ref and wait for any remaining references
	 * to be dropped, as well as a RCU grace period for anyone only
	 * using the namepace under rcu_read_lock().  Note that we can't
	 * use call_rcu here as we need to ensure the namespaces have
	 * been fully destroyed before unloading the module.
	 */
	percpu_ref_kill(&ns->ref);
	synchronize_rcu();
	wait_for_completion(&ns->disable_done);
	percpu_ref_exit(&ns->ref);

	mutex_lock(&subsys->lock);
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	subsys->nr_namespaces--;
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	nvmet_ns_changed(subsys, ns->nsid);
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	nvmet_ns_dev_disable(ns);
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out_unlock:
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	mutex_unlock(&subsys->lock);
}

void nvmet_ns_free(struct nvmet_ns *ns)
{
	nvmet_ns_disable(ns);

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	down_write(&nvmet_ana_sem);
	nvmet_ana_group_enabled[ns->anagrpid]--;
	up_write(&nvmet_ana_sem);

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	kfree(ns->device_path);
	kfree(ns);
}

struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
{
	struct nvmet_ns *ns;

	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
	if (!ns)
		return NULL;

	INIT_LIST_HEAD(&ns->dev_link);
	init_completion(&ns->disable_done);

	ns->nsid = nsid;
	ns->subsys = subsys;
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	down_write(&nvmet_ana_sem);
	ns->anagrpid = NVMET_DEFAULT_ANA_GRPID;
	nvmet_ana_group_enabled[ns->anagrpid]++;
	up_write(&nvmet_ana_sem);

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	uuid_gen(&ns->uuid);
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	ns->buffered_io = false;
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	return ns;
}

static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
{
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	u32 old_sqhd, new_sqhd;
	u16 sqhd;

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	if (status)
		nvmet_set_status(req, status);

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	if (req->sq->size) {
		do {
			old_sqhd = req->sq->sqhd;
			new_sqhd = (old_sqhd + 1) % req->sq->size;
		} while (cmpxchg(&req->sq->sqhd, old_sqhd, new_sqhd) !=
					old_sqhd);
	}
	sqhd = req->sq->sqhd & 0x0000FFFF;
	req->rsp->sq_head = cpu_to_le16(sqhd);
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	req->rsp->sq_id = cpu_to_le16(req->sq->qid);
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	req->rsp->command_id = req->cmd->common.command_id;

	if (req->ns)
		nvmet_put_namespace(req->ns);
	req->ops->queue_response(req);
}

void nvmet_req_complete(struct nvmet_req *req, u16 status)
{
	__nvmet_req_complete(req, status);
	percpu_ref_put(&req->sq->ref);
}
EXPORT_SYMBOL_GPL(nvmet_req_complete);

void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
		u16 qid, u16 size)
{
	cq->qid = qid;
	cq->size = size;

	ctrl->cqs[qid] = cq;
}

void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
		u16 qid, u16 size)
{
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	sq->sqhd = 0;
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	sq->qid = qid;
	sq->size = size;

	ctrl->sqs[qid] = sq;
}

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static void nvmet_confirm_sq(struct percpu_ref *ref)
{
	struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);

	complete(&sq->confirm_done);
}

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void nvmet_sq_destroy(struct nvmet_sq *sq)
{
	/*
	 * If this is the admin queue, complete all AERs so that our
	 * queue doesn't have outstanding requests on it.
	 */
	if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq)
		nvmet_async_events_free(sq->ctrl);
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	percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
	wait_for_completion(&sq->confirm_done);
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	wait_for_completion(&sq->free_done);
	percpu_ref_exit(&sq->ref);

	if (sq->ctrl) {
		nvmet_ctrl_put(sq->ctrl);
		sq->ctrl = NULL; /* allows reusing the queue later */
	}
}
EXPORT_SYMBOL_GPL(nvmet_sq_destroy);

static void nvmet_sq_free(struct percpu_ref *ref)
{
	struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);

	complete(&sq->free_done);
}

int nvmet_sq_init(struct nvmet_sq *sq)
{
	int ret;

	ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
	if (ret) {
		pr_err("percpu_ref init failed!\n");
		return ret;
	}
	init_completion(&sq->free_done);
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	init_completion(&sq->confirm_done);
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	return 0;
}
EXPORT_SYMBOL_GPL(nvmet_sq_init);

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static inline u16 nvmet_check_ana_state(struct nvmet_port *port,
		struct nvmet_ns *ns)
{
	enum nvme_ana_state state = port->ana_state[ns->anagrpid];

	if (unlikely(state == NVME_ANA_INACCESSIBLE))
		return NVME_SC_ANA_INACCESSIBLE;
	if (unlikely(state == NVME_ANA_PERSISTENT_LOSS))
		return NVME_SC_ANA_PERSISTENT_LOSS;
	if (unlikely(state == NVME_ANA_CHANGE))
		return NVME_SC_ANA_TRANSITION;
	return 0;
}

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static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
{
	if (unlikely(req->ns->readonly)) {
		switch (req->cmd->common.opcode) {
		case nvme_cmd_read:
		case nvme_cmd_flush:
			break;
		default:
			return NVME_SC_NS_WRITE_PROTECTED;
		}
	}

	return 0;
}

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static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
{
	struct nvme_command *cmd = req->cmd;
	u16 ret;

	ret = nvmet_check_ctrl_status(req, cmd);
	if (unlikely(ret))
		return ret;

	req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
	if (unlikely(!req->ns))
		return NVME_SC_INVALID_NS | NVME_SC_DNR;
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	ret = nvmet_check_ana_state(req->port, req->ns);
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	if (unlikely(ret))
		return ret;
	ret = nvmet_io_cmd_check_access(req);
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	if (unlikely(ret))
		return ret;
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	if (req->ns->file)
		return nvmet_file_parse_io_cmd(req);
	else
		return nvmet_bdev_parse_io_cmd(req);
}

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bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
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		struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops)
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{
	u8 flags = req->cmd->common.flags;
	u16 status;

	req->cq = cq;
	req->sq = sq;
	req->ops = ops;
	req->sg = NULL;
	req->sg_cnt = 0;
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	req->transfer_len = 0;
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	req->rsp->status = 0;
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	req->ns = NULL;
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	/* no support for fused commands yet */
	if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
		goto fail;
	}

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	/*
	 * For fabrics, PSDT field shall describe metadata pointer (MPTR) that
	 * contains an address of a single contiguous physical buffer that is
	 * byte aligned.
	 */
	if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF)) {
679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710
		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
		goto fail;
	}

	if (unlikely(!req->sq->ctrl))
		/* will return an error for any Non-connect command: */
		status = nvmet_parse_connect_cmd(req);
	else if (likely(req->sq->qid != 0))
		status = nvmet_parse_io_cmd(req);
	else if (req->cmd->common.opcode == nvme_fabrics_command)
		status = nvmet_parse_fabrics_cmd(req);
	else if (req->sq->ctrl->subsys->type == NVME_NQN_DISC)
		status = nvmet_parse_discovery_cmd(req);
	else
		status = nvmet_parse_admin_cmd(req);

	if (status)
		goto fail;

	if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
		goto fail;
	}

	return true;

fail:
	__nvmet_req_complete(req, status);
	return false;
}
EXPORT_SYMBOL_GPL(nvmet_req_init);

711 712 713
void nvmet_req_uninit(struct nvmet_req *req)
{
	percpu_ref_put(&req->sq->ref);
714 715
	if (req->ns)
		nvmet_put_namespace(req->ns);
716 717 718
}
EXPORT_SYMBOL_GPL(nvmet_req_uninit);

719 720 721 722 723 724 725 726 727
void nvmet_req_execute(struct nvmet_req *req)
{
	if (unlikely(req->data_len != req->transfer_len))
		nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
	else
		req->execute(req);
}
EXPORT_SYMBOL_GPL(nvmet_req_execute);

728 729
static inline bool nvmet_cc_en(u32 cc)
{
730
	return (cc >> NVME_CC_EN_SHIFT) & 0x1;
731 732 733 734
}

static inline u8 nvmet_cc_css(u32 cc)
{
735
	return (cc >> NVME_CC_CSS_SHIFT) & 0x7;
736 737 738 739
}

static inline u8 nvmet_cc_mps(u32 cc)
{
740
	return (cc >> NVME_CC_MPS_SHIFT) & 0xf;
741 742 743 744
}

static inline u8 nvmet_cc_ams(u32 cc)
{
745
	return (cc >> NVME_CC_AMS_SHIFT) & 0x7;
746 747 748 749
}

static inline u8 nvmet_cc_shn(u32 cc)
{
750
	return (cc >> NVME_CC_SHN_SHIFT) & 0x3;
751 752 753 754
}

static inline u8 nvmet_cc_iosqes(u32 cc)
{
755
	return (cc >> NVME_CC_IOSQES_SHIFT) & 0xf;
756 757 758 759
}

static inline u8 nvmet_cc_iocqes(u32 cc)
{
760
	return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776
}

static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
{
	lockdep_assert_held(&ctrl->lock);

	if (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
	    nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES ||
	    nvmet_cc_mps(ctrl->cc) != 0 ||
	    nvmet_cc_ams(ctrl->cc) != 0 ||
	    nvmet_cc_css(ctrl->cc) != 0) {
		ctrl->csts = NVME_CSTS_CFS;
		return;
	}

	ctrl->csts = NVME_CSTS_RDY;
777 778 779 780 781 782 783 784

	/*
	 * Controllers that are not yet enabled should not really enforce the
	 * keep alive timeout, but we still want to track a timeout and cleanup
	 * in case a host died before it enabled the controller.  Hence, simply
	 * reset the keep alive timer when the controller is enabled.
	 */
	mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
}

static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
{
	lockdep_assert_held(&ctrl->lock);

	/* XXX: tear down queues? */
	ctrl->csts &= ~NVME_CSTS_RDY;
	ctrl->cc = 0;
}

void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
{
	u32 old;

	mutex_lock(&ctrl->lock);
	old = ctrl->cc;
	ctrl->cc = new;

	if (nvmet_cc_en(new) && !nvmet_cc_en(old))
		nvmet_start_ctrl(ctrl);
	if (!nvmet_cc_en(new) && nvmet_cc_en(old))
		nvmet_clear_ctrl(ctrl);
	if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
		nvmet_clear_ctrl(ctrl);
		ctrl->csts |= NVME_CSTS_SHST_CMPLT;
	}
	if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
		ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
	mutex_unlock(&ctrl->lock);
}

static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
{
	/* command sets supported: NVMe command set: */
	ctrl->cap = (1ULL << 37);
	/* CC.EN timeout in 500msec units: */
	ctrl->cap |= (15ULL << 24);
	/* maximum queue entries supported: */
	ctrl->cap |= NVMET_QUEUE_SIZE - 1;
}

u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
		struct nvmet_req *req, struct nvmet_ctrl **ret)
{
	struct nvmet_subsys *subsys;
	struct nvmet_ctrl *ctrl;
	u16 status = 0;

	subsys = nvmet_find_get_subsys(req->port, subsysnqn);
	if (!subsys) {
		pr_warn("connect request for invalid subsystem %s!\n",
			subsysnqn);
838
		req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858
		return NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
	}

	mutex_lock(&subsys->lock);
	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
		if (ctrl->cntlid == cntlid) {
			if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
				pr_warn("hostnqn mismatch.\n");
				continue;
			}
			if (!kref_get_unless_zero(&ctrl->ref))
				continue;

			*ret = ctrl;
			goto out;
		}
	}

	pr_warn("could not find controller %d for subsys %s / host %s\n",
		cntlid, subsysnqn, hostnqn);
859
	req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
860 861 862 863 864 865 866 867
	status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;

out:
	mutex_unlock(&subsys->lock);
	nvmet_subsys_put(subsys);
	return status;
}

868 869 870
u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd)
{
	if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
871
		pr_err("got cmd %d while CC.EN == 0 on qid = %d\n",
872 873 874 875 876
		       cmd->common.opcode, req->sq->qid);
		return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
	}

	if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
877
		pr_err("got cmd %d while CSTS.RDY == 0 on qid = %d\n",
878 879 880 881 882 883
		       cmd->common.opcode, req->sq->qid);
		return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
	}
	return 0;
}

884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
static bool __nvmet_host_allowed(struct nvmet_subsys *subsys,
		const char *hostnqn)
{
	struct nvmet_host_link *p;

	if (subsys->allow_any_host)
		return true;

	list_for_each_entry(p, &subsys->hosts, entry) {
		if (!strcmp(nvmet_host_name(p->host), hostnqn))
			return true;
	}

	return false;
}

static bool nvmet_host_discovery_allowed(struct nvmet_req *req,
		const char *hostnqn)
{
	struct nvmet_subsys_link *s;

	list_for_each_entry(s, &req->port->subsystems, entry) {
		if (__nvmet_host_allowed(s->subsys, hostnqn))
			return true;
	}

	return false;
}

bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
		const char *hostnqn)
{
	lockdep_assert_held(&nvmet_config_sem);

	if (subsys->type == NVME_NQN_DISC)
		return nvmet_host_discovery_allowed(req, hostnqn);
	else
		return __nvmet_host_allowed(subsys, hostnqn);
}

u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
		struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
{
	struct nvmet_subsys *subsys;
	struct nvmet_ctrl *ctrl;
	int ret;
	u16 status;

	status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
	subsys = nvmet_find_get_subsys(req->port, subsysnqn);
	if (!subsys) {
		pr_warn("connect request for invalid subsystem %s!\n",
			subsysnqn);
937
		req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
938 939 940 941 942 943 944 945
		goto out;
	}

	status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
	down_read(&nvmet_config_sem);
	if (!nvmet_host_allowed(req, subsys, hostnqn)) {
		pr_info("connect by host %s for subsystem %s not allowed\n",
			hostnqn, subsysnqn);
946
		req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(hostnqn);
947
		up_read(&nvmet_config_sem);
948
		status = NVME_SC_CONNECT_INVALID_HOST | NVME_SC_DNR;
949 950 951 952 953 954 955 956 957 958 959 960
		goto out_put_subsystem;
	}
	up_read(&nvmet_config_sem);

	status = NVME_SC_INTERNAL;
	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
	if (!ctrl)
		goto out_put_subsystem;
	mutex_init(&ctrl->lock);

	nvmet_init_cap(ctrl);

961 962
	ctrl->port = req->port;

963 964 965 966 967 968 969 970
	INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
	INIT_LIST_HEAD(&ctrl->async_events);

	memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
	memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);

	kref_init(&ctrl->ref);
	ctrl->subsys = subsys;
971
	WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
972

973 974 975 976 977
	ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
			sizeof(__le32), GFP_KERNEL);
	if (!ctrl->changed_ns_list)
		goto out_free_ctrl;

978 979 980 981
	ctrl->cqs = kcalloc(subsys->max_qid + 1,
			sizeof(struct nvmet_cq *),
			GFP_KERNEL);
	if (!ctrl->cqs)
982
		goto out_free_changed_ns_list;
983 984 985 986 987 988 989

	ctrl->sqs = kcalloc(subsys->max_qid + 1,
			sizeof(struct nvmet_sq *),
			GFP_KERNEL);
	if (!ctrl->sqs)
		goto out_free_cqs;

990
	ret = ida_simple_get(&cntlid_ida,
991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
			     NVME_CNTLID_MIN, NVME_CNTLID_MAX,
			     GFP_KERNEL);
	if (ret < 0) {
		status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
		goto out_free_sqs;
	}
	ctrl->cntlid = ret;

	ctrl->ops = req->ops;
	if (ctrl->subsys->type == NVME_NQN_DISC) {
		/* Don't accept keep-alive timeout for discovery controllers */
		if (kato) {
			status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
1004
			goto out_remove_ida;
1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
		}

		/*
		 * Discovery controllers use some arbitrary high value in order
		 * to cleanup stale discovery sessions
		 *
		 * From the latest base diff RC:
		 * "The Keep Alive command is not supported by
		 * Discovery controllers. A transport may specify a
		 * fixed Discovery controller activity timeout value
		 * (e.g., 2 minutes).  If no commands are received
		 * by a Discovery controller within that time
		 * period, the controller may perform the
		 * actions for Keep Alive Timer expiration".
		 */
		ctrl->kato = NVMET_DISC_KATO;
	} else {
		/* keep-alive timeout in seconds */
		ctrl->kato = DIV_ROUND_UP(kato, 1000);
	}
	nvmet_start_keep_alive_timer(ctrl);

	mutex_lock(&subsys->lock);
	list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
	mutex_unlock(&subsys->lock);

	*ctrlp = ctrl;
	return 0;

1034 1035
out_remove_ida:
	ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1036 1037 1038 1039
out_free_sqs:
	kfree(ctrl->sqs);
out_free_cqs:
	kfree(ctrl->cqs);
1040 1041
out_free_changed_ns_list:
	kfree(ctrl->changed_ns_list);
1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
out_free_ctrl:
	kfree(ctrl);
out_put_subsystem:
	nvmet_subsys_put(subsys);
out:
	return status;
}

static void nvmet_ctrl_free(struct kref *ref)
{
	struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
	struct nvmet_subsys *subsys = ctrl->subsys;

	mutex_lock(&subsys->lock);
	list_del(&ctrl->subsys_entry);
	mutex_unlock(&subsys->lock);

1059 1060
	nvmet_stop_keep_alive_timer(ctrl);

1061 1062 1063
	flush_work(&ctrl->async_event_work);
	cancel_work_sync(&ctrl->fatal_err_work);

1064
	ida_simple_remove(&cntlid_ida, ctrl->cntlid);
1065 1066 1067

	kfree(ctrl->sqs);
	kfree(ctrl->cqs);
1068
	kfree(ctrl->changed_ns_list);
1069
	kfree(ctrl);
1070 1071

	nvmet_subsys_put(subsys);
1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089
}

void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
{
	kref_put(&ctrl->ref, nvmet_ctrl_free);
}

static void nvmet_fatal_error_handler(struct work_struct *work)
{
	struct nvmet_ctrl *ctrl =
			container_of(work, struct nvmet_ctrl, fatal_err_work);

	pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
	ctrl->ops->delete_ctrl(ctrl);
}

void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
{
1090 1091 1092 1093 1094 1095 1096
	mutex_lock(&ctrl->lock);
	if (!(ctrl->csts & NVME_CSTS_CFS)) {
		ctrl->csts |= NVME_CSTS_CFS;
		INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
		schedule_work(&ctrl->fatal_err_work);
	}
	mutex_unlock(&ctrl->lock);
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
}
EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);

static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
		const char *subsysnqn)
{
	struct nvmet_subsys_link *p;

	if (!port)
		return NULL;

	if (!strncmp(NVME_DISC_SUBSYS_NAME, subsysnqn,
			NVMF_NQN_SIZE)) {
		if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
			return NULL;
		return nvmet_disc_subsys;
	}

	down_read(&nvmet_config_sem);
	list_for_each_entry(p, &port->subsystems, entry) {
		if (!strncmp(p->subsys->subsysnqn, subsysnqn,
				NVMF_NQN_SIZE)) {
			if (!kref_get_unless_zero(&p->subsys->ref))
				break;
			up_read(&nvmet_config_sem);
			return p->subsys;
		}
	}
	up_read(&nvmet_config_sem);
	return NULL;
}

struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
		enum nvme_subsys_type type)
{
	struct nvmet_subsys *subsys;

	subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
	if (!subsys)
		return NULL;

1138
	subsys->ver = NVME_VS(1, 3, 0); /* NVMe 1.3.0 */
1139 1140
	/* generate a random serial number as our controllers are ephemeral: */
	get_random_bytes(&subsys->serial, sizeof(subsys->serial));
1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156

	switch (type) {
	case NVME_NQN_NVME:
		subsys->max_qid = NVMET_NR_QUEUES;
		break;
	case NVME_NQN_DISC:
		subsys->max_qid = 0;
		break;
	default:
		pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
		kfree(subsys);
		return NULL;
	}
	subsys->type = type;
	subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
			GFP_KERNEL);
1157
	if (!subsys->subsysnqn) {
1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
		kfree(subsys);
		return NULL;
	}

	kref_init(&subsys->ref);

	mutex_init(&subsys->lock);
	INIT_LIST_HEAD(&subsys->namespaces);
	INIT_LIST_HEAD(&subsys->ctrls);
	INIT_LIST_HEAD(&subsys->hosts);

	return subsys;
}

static void nvmet_subsys_free(struct kref *ref)
{
	struct nvmet_subsys *subsys =
		container_of(ref, struct nvmet_subsys, ref);

	WARN_ON_ONCE(!list_empty(&subsys->namespaces));

	kfree(subsys->subsysnqn);
	kfree(subsys);
}

1183 1184 1185 1186 1187 1188 1189 1190 1191 1192
void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys)
{
	struct nvmet_ctrl *ctrl;

	mutex_lock(&subsys->lock);
	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
		ctrl->ops->delete_ctrl(ctrl);
	mutex_unlock(&subsys->lock);
}

1193 1194 1195 1196 1197 1198 1199 1200 1201
void nvmet_subsys_put(struct nvmet_subsys *subsys)
{
	kref_put(&subsys->ref, nvmet_subsys_free);
}

static int __init nvmet_init(void)
{
	int error;

1202 1203
	nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;

1204 1205 1206 1207 1208 1209
	buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
			WQ_MEM_RECLAIM, 0);
	if (!buffered_io_wq) {
		error = -ENOMEM;
		goto out;
	}
1210

1211 1212
	error = nvmet_init_discovery();
	if (error)
1213
		goto out_free_work_queue;
1214 1215 1216 1217 1218 1219 1220 1221

	error = nvmet_init_configfs();
	if (error)
		goto out_exit_discovery;
	return 0;

out_exit_discovery:
	nvmet_exit_discovery();
1222 1223
out_free_work_queue:
	destroy_workqueue(buffered_io_wq);
1224 1225 1226 1227 1228 1229 1230 1231
out:
	return error;
}

static void __exit nvmet_exit(void)
{
	nvmet_exit_configfs();
	nvmet_exit_discovery();
1232
	ida_destroy(&cntlid_ida);
1233
	destroy_workqueue(buffered_io_wq);
1234 1235 1236 1237 1238 1239 1240 1241 1242

	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
}

module_init(nvmet_init);
module_exit(nvmet_exit);

MODULE_LICENSE("GPL v2");