https://github.com/torvalds/linux
Tip revision: 0b07194bb55ed836c2cc7c22e866b87a14681984 authored by Linus Torvalds on 29 October 2017, 20:58:38 UTC
Linux 4.14-rc7
Linux 4.14-rc7
Tip revision: 0b07194
discovery.c
/*
* 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, 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, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE);
memcpy(e->subnqn, subsys_nqn, NVMF_NQN_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) {
nvmet_format_discovery_entry(hdr, req->port,
p->subsys->subsysnqn,
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,
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);
}