diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/nvme/target/discovery.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c new file mode 100644 index 000000000..eae29f493 --- /dev/null +++ b/drivers/nvme/target/discovery.c @@ -0,0 +1,242 @@ +/* + * 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 (req->port->inline_data_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; + + 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); +} |