drivers/nvme/target/discovery.c - linux - Git at Google

 /*
  * Discovery service for the NVMe over Fabrics target.
  * Copyright (C) 2016 Intel Corporation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version
  * 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that 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/slab.h>
 #include <generated/utsrelease.h>
 #include "nvmet.h"

 struct nvmet_subsys *nvmet_disc_subsys;

 u64 nvmet_genctr;

 void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port)
 {
 	down_write(&nvmet_config_sem);
 	if (list_empty(&port->entry)) {
 		list_add_tail(&port->entry, &parent->referrals);
 		port->enabled = true;
 		nvmet_genctr++;
 	}
 	up_write(&nvmet_config_sem);
 }

 void nvmet_referral_disable(struct nvmet_port *port)
 {
 	down_write(&nvmet_config_sem);
 	if (!list_empty(&port->entry)) {
 		port->enabled = false;
 		list_del_init(&port->entry);
 		nvmet_genctr++;
 	}
 	up_write(&nvmet_config_sem);
 }

 static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr,
 		struct nvmet_port *port, char *subsys_nqn, char *traddr,
 		u8 type, u32 numrec)
 {
 	struct nvmf_disc_rsp_page_entry *e = &hdr->entries[numrec];

 	e->trtype = port->disc_addr.trtype;
 	e->adrfam = port->disc_addr.adrfam;
 	e->treq = port->disc_addr.treq;
 	e->portid = port->disc_addr.portid;
 	/* we support only dynamic controllers */
 	e->cntlid = cpu_to_le16(NVME_CNTLID_DYNAMIC);
 	e->asqsz = cpu_to_le16(NVME_AQ_DEPTH);
 	e->subtype = type;
 	memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE);
 	memcpy(e->traddr, traddr, NVMF_TRADDR_SIZE);
 	memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE);
 	strncpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE);
 }

 /*
  * nvmet_set_disc_traddr - set a correct discovery log entry traddr
  *
  * IP based transports (e.g RDMA) can listen on "any" ipv4/ipv6 addresses
  * (INADDR_ANY or IN6ADDR_ANY_INIT). The discovery log page traddr reply
  * must not contain that "any" IP address. If the transport implements
  * .disc_traddr, use it. this callback will set the discovery traddr
  * from the req->port address in case the port in question listens
  * "any" IP address.
  */
 static void nvmet_set_disc_traddr(struct nvmet_req *req, struct nvmet_port *port,
 		char *traddr)
 {
 	if (req->ops->disc_traddr)
 		req->ops->disc_traddr(req, port, traddr);
 	else
 		memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
 }

 static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
 {
 	const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
 	struct nvmet_ctrl *ctrl = req->sq->ctrl;
 	struct nvmf_disc_rsp_page_hdr *hdr;
 	size_t data_len = nvmet_get_log_page_len(req->cmd);
 	size_t alloc_len = max(data_len, sizeof(*hdr));
 	int residual_len = data_len - sizeof(*hdr);
 	struct nvmet_subsys_link *p;
 	struct nvmet_port *r;
 	u32 numrec = 0;
 	u16 status = 0;

 	/*
 	 * Make sure we're passing at least a buffer of response header size.
 	 * If host provided data len is less than the header size, only the
 	 * number of bytes requested by host will be sent to host.
 	 */
 	hdr = kzalloc(alloc_len, GFP_KERNEL);
 	if (!hdr) {
 		status = NVME_SC_INTERNAL;
 		goto out;
 	}

 	down_read(&nvmet_config_sem);
 	list_for_each_entry(p, &req->port->subsystems, entry) {
 		if (!nvmet_host_allowed(req, p->subsys, ctrl->hostnqn))
 			continue;
 		if (residual_len >= entry_size) {
 			char traddr[NVMF_TRADDR_SIZE];

 			nvmet_set_disc_traddr(req, req->port, traddr);
 			nvmet_format_discovery_entry(hdr, req->port,
 					p->subsys->subsysnqn, traddr,
 					NVME_NQN_NVME, numrec);
 			residual_len -= entry_size;
 		}
 		numrec++;
 	}

 	list_for_each_entry(r, &req->port->referrals, entry) {
 		if (residual_len >= entry_size) {
 			nvmet_format_discovery_entry(hdr, r,
 					NVME_DISC_SUBSYS_NAME,
 					r->disc_addr.traddr,
 					NVME_NQN_DISC, numrec);
 			residual_len -= entry_size;
 		}
 		numrec++;
 	}

 	hdr->genctr = cpu_to_le64(nvmet_genctr);
 	hdr->numrec = cpu_to_le64(numrec);
 	hdr->recfmt = cpu_to_le16(0);

 	up_read(&nvmet_config_sem);

 	status = nvmet_copy_to_sgl(req, 0, hdr, data_len);
 	kfree(hdr);
 out:
 	nvmet_req_complete(req, status);
 }

 static void nvmet_execute_identify_disc_ctrl(struct nvmet_req *req)
 {
 	struct nvmet_ctrl *ctrl = req->sq->ctrl;
 	struct nvme_id_ctrl *id;
 	u16 status = 0;

 	id = kzalloc(sizeof(*id), GFP_KERNEL);
 	if (!id) {
 		status = NVME_SC_INTERNAL;
 		goto out;
 	}

 	memset(id->fr, ' ', sizeof(id->fr));
 	strncpy((char *)id->fr, UTS_RELEASE, sizeof(id->fr));

 	/* no limit on data transfer sizes for now */
 	id->mdts = 0;
 	id->cntlid = cpu_to_le16(ctrl->cntlid);
 	id->ver = cpu_to_le32(ctrl->subsys->ver);
 	id->lpa = (1 << 2);

 	/* no enforcement soft-limit for maxcmd - pick arbitrary high value */
 	id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);

 	id->sgls = cpu_to_le32(1 << 0);	/* we always support SGLs */
 	if (ctrl->ops->has_keyed_sgls)
 		id->sgls |= cpu_to_le32(1 << 2);
 	if (ctrl->ops->sqe_inline_size)
 		id->sgls |= cpu_to_le32(1 << 20);

 	strcpy(id->subnqn, ctrl->subsys->subsysnqn);

 	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));

 	kfree(id);
 out:
 	nvmet_req_complete(req, status);
 }

 u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
 {
 	struct nvme_command *cmd = req->cmd;

 	req->ns = NULL;

 	if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
 		pr_err("got cmd %d while not ready\n",
 		       cmd->common.opcode);
 		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 	}

 	switch (cmd->common.opcode) {
 	case nvme_admin_get_log_page:
 		req->data_len = nvmet_get_log_page_len(cmd);

 		switch (cmd->get_log_page.lid) {
 		case NVME_LOG_DISC:
 			req->execute = nvmet_execute_get_disc_log_page;
 			return 0;
 		default:
 			pr_err("unsupported get_log_page lid %d\n",
 			       cmd->get_log_page.lid);
 		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 		}
 	case nvme_admin_identify:
 		req->data_len = NVME_IDENTIFY_DATA_SIZE;
 		switch (cmd->identify.cns) {
 		case NVME_ID_CNS_CTRL:
 			req->execute =
 				nvmet_execute_identify_disc_ctrl;
 			return 0;
 		default:
 			pr_err("unsupported identify cns %d\n",
 			       cmd->identify.cns);
 			return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 		}
 	default:
 		pr_err("unsupported cmd %d\n", cmd->common.opcode);
 		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 	}

 	pr_err("unhandled cmd %d\n", cmd->common.opcode);
 	return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 }

 int __init nvmet_init_discovery(void)
 {
 	nvmet_disc_subsys =
 		nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_DISC);
 	if (!nvmet_disc_subsys)
 		return -ENOMEM;
 	return 0;
 }

 void nvmet_exit_discovery(void)
 {
 	nvmet_subsys_put(nvmet_disc_subsys);
 }
	/*
	* Discovery service for the NVMe over Fabrics target.
	* Copyright (C) 2016 Intel Corporation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License version
	* 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that 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/slab.h>
	#include <generated/utsrelease.h>
	#include "nvmet.h"

	struct nvmet_subsys *nvmet_disc_subsys;

	u64 nvmet_genctr;

	void nvmet_referral_enable(struct nvmet_port parent, struct nvmet_port port)
	{
	down_write(&nvmet_config_sem);
	if (list_empty(&port->entry)) {
	list_add_tail(&port->entry, &parent->referrals);
	port->enabled = true;
	nvmet_genctr++;
	}
	up_write(&nvmet_config_sem);
	}

	void nvmet_referral_disable(struct nvmet_port *port)
	{
	down_write(&nvmet_config_sem);
	if (!list_empty(&port->entry)) {
	port->enabled = false;
	list_del_init(&port->entry);
	nvmet_genctr++;
	}
	up_write(&nvmet_config_sem);
	}

	static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr,
	struct nvmet_port port, char subsys_nqn, char *traddr,
	u8 type, u32 numrec)
	{
	struct nvmf_disc_rsp_page_entry *e = &hdr->entries[numrec];

	e->trtype = port->disc_addr.trtype;
	e->adrfam = port->disc_addr.adrfam;
	e->treq = port->disc_addr.treq;
	e->portid = port->disc_addr.portid;
	/* we support only dynamic controllers */
	e->cntlid = cpu_to_le16(NVME_CNTLID_DYNAMIC);
	e->asqsz = cpu_to_le16(NVME_AQ_DEPTH);
	e->subtype = type;
	memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE);
	memcpy(e->traddr, traddr, NVMF_TRADDR_SIZE);
	memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE);
	strncpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE);
	}

	/*
	* nvmet_set_disc_traddr - set a correct discovery log entry traddr
	*
	* IP based transports (e.g RDMA) can listen on "any" ipv4/ipv6 addresses
	* (INADDR_ANY or IN6ADDR_ANY_INIT). The discovery log page traddr reply
	* must not contain that "any" IP address. If the transport implements
	* .disc_traddr, use it. this callback will set the discovery traddr
	* from the req->port address in case the port in question listens
	* "any" IP address.
	*/
	static void nvmet_set_disc_traddr(struct nvmet_req req, struct nvmet_port port,
	char *traddr)
	{
	if (req->ops->disc_traddr)
	req->ops->disc_traddr(req, port, traddr);
	else
	memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
	}

	static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
	{
	const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
	struct nvmet_ctrl *ctrl = req->sq->ctrl;
	struct nvmf_disc_rsp_page_hdr *hdr;
	size_t data_len = nvmet_get_log_page_len(req->cmd);
	size_t alloc_len = max(data_len, sizeof(*hdr));
	int residual_len = data_len - sizeof(*hdr);
	struct nvmet_subsys_link *p;
	struct nvmet_port *r;
	u32 numrec = 0;
	u16 status = 0;

	/*
	* Make sure we're passing at least a buffer of response header size.
	* If host provided data len is less than the header size, only the
	* number of bytes requested by host will be sent to host.
	*/
	hdr = kzalloc(alloc_len, GFP_KERNEL);
	if (!hdr) {
	status = NVME_SC_INTERNAL;
	goto out;
	}

	down_read(&nvmet_config_sem);
	list_for_each_entry(p, &req->port->subsystems, entry) {
	if (!nvmet_host_allowed(req, p->subsys, ctrl->hostnqn))
	continue;
	if (residual_len >= entry_size) {
	char traddr[NVMF_TRADDR_SIZE];

	nvmet_set_disc_traddr(req, req->port, traddr);
	nvmet_format_discovery_entry(hdr, req->port,
	p->subsys->subsysnqn, traddr,
	NVME_NQN_NVME, numrec);
	residual_len -= entry_size;
	}
	numrec++;
	}

	list_for_each_entry(r, &req->port->referrals, entry) {
	if (residual_len >= entry_size) {
	nvmet_format_discovery_entry(hdr, r,
	NVME_DISC_SUBSYS_NAME,
	r->disc_addr.traddr,
	NVME_NQN_DISC, numrec);
	residual_len -= entry_size;
	}
	numrec++;
	}

	hdr->genctr = cpu_to_le64(nvmet_genctr);
	hdr->numrec = cpu_to_le64(numrec);
	hdr->recfmt = cpu_to_le16(0);

	up_read(&nvmet_config_sem);

	status = nvmet_copy_to_sgl(req, 0, hdr, data_len);
	kfree(hdr);
	out:
	nvmet_req_complete(req, status);
	}

	static void nvmet_execute_identify_disc_ctrl(struct nvmet_req *req)
	{
	struct nvmet_ctrl *ctrl = req->sq->ctrl;
	struct nvme_id_ctrl *id;
	u16 status = 0;

	id = kzalloc(sizeof(*id), GFP_KERNEL);
	if (!id) {
	status = NVME_SC_INTERNAL;
	goto out;
	}

	memset(id->fr, ' ', sizeof(id->fr));
	strncpy((char *)id->fr, UTS_RELEASE, sizeof(id->fr));

	/* no limit on data transfer sizes for now */
	id->mdts = 0;
	id->cntlid = cpu_to_le16(ctrl->cntlid);
	id->ver = cpu_to_le32(ctrl->subsys->ver);
	id->lpa = (1 << 2);

	/* no enforcement soft-limit for maxcmd - pick arbitrary high value */
	id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);

	id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
	if (ctrl->ops->has_keyed_sgls)
	id->sgls \|= cpu_to_le32(1 << 2);
	if (ctrl->ops->sqe_inline_size)
	id->sgls \|= cpu_to_le32(1 << 20);

	strcpy(id->subnqn, ctrl->subsys->subsysnqn);

	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));

	kfree(id);
	out:
	nvmet_req_complete(req, status);
	}

	u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
	{
	struct nvme_command *cmd = req->cmd;

	req->ns = NULL;

	if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
	pr_err("got cmd %d while not ready\n",
	cmd->common.opcode);
	return NVME_SC_INVALID_OPCODE \| NVME_SC_DNR;
	}

	switch (cmd->common.opcode) {
	case nvme_admin_get_log_page:
	req->data_len = nvmet_get_log_page_len(cmd);

	switch (cmd->get_log_page.lid) {
	case NVME_LOG_DISC:
	req->execute = nvmet_execute_get_disc_log_page;
	return 0;
	default:
	pr_err("unsupported get_log_page lid %d\n",
	cmd->get_log_page.lid);
	return NVME_SC_INVALID_OPCODE \| NVME_SC_DNR;
	}
	case nvme_admin_identify:
	req->data_len = NVME_IDENTIFY_DATA_SIZE;
	switch (cmd->identify.cns) {
	case NVME_ID_CNS_CTRL:
	req->execute =
	nvmet_execute_identify_disc_ctrl;
	return 0;
	default:
	pr_err("unsupported identify cns %d\n",
	cmd->identify.cns);
	return NVME_SC_INVALID_OPCODE \| NVME_SC_DNR;
	}
	default:
	pr_err("unsupported cmd %d\n", cmd->common.opcode);
	return NVME_SC_INVALID_OPCODE \| NVME_SC_DNR;
	}

	pr_err("unhandled cmd %d\n", cmd->common.opcode);
	return NVME_SC_INVALID_OPCODE \| NVME_SC_DNR;
	}

	int __init nvmet_init_discovery(void)
	{
	nvmet_disc_subsys =
	nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_DISC);
	if (!nvmet_disc_subsys)
	return -ENOMEM;
	return 0;
	}

	void nvmet_exit_discovery(void)
	{
	nvmet_subsys_put(nvmet_disc_subsys);
	}