Christoph Hellwig | a07b497 | 2016-06-21 18:04:20 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Discovery service for the NVMe over Fabrics target. |
| 3 | * Copyright (C) 2016 Intel Corporation. All rights reserved. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License version |
| 7 | * 2 as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | */ |
| 14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 15 | #include <linux/slab.h> |
| 16 | #include <generated/utsrelease.h> |
| 17 | #include "nvmet.h" |
| 18 | |
| 19 | struct nvmet_subsys *nvmet_disc_subsys; |
| 20 | |
| 21 | u64 nvmet_genctr; |
| 22 | |
| 23 | void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port) |
| 24 | { |
| 25 | down_write(&nvmet_config_sem); |
| 26 | if (list_empty(&port->entry)) { |
| 27 | list_add_tail(&port->entry, &parent->referrals); |
| 28 | port->enabled = true; |
| 29 | nvmet_genctr++; |
| 30 | } |
| 31 | up_write(&nvmet_config_sem); |
| 32 | } |
| 33 | |
| 34 | void nvmet_referral_disable(struct nvmet_port *port) |
| 35 | { |
| 36 | down_write(&nvmet_config_sem); |
| 37 | if (!list_empty(&port->entry)) { |
| 38 | port->enabled = false; |
| 39 | list_del_init(&port->entry); |
| 40 | nvmet_genctr++; |
| 41 | } |
| 42 | up_write(&nvmet_config_sem); |
| 43 | } |
| 44 | |
| 45 | static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr, |
| 46 | struct nvmet_port *port, char *subsys_nqn, u8 type, u32 numrec) |
| 47 | { |
| 48 | struct nvmf_disc_rsp_page_entry *e = &hdr->entries[numrec]; |
| 49 | |
| 50 | e->trtype = port->disc_addr.trtype; |
| 51 | e->adrfam = port->disc_addr.adrfam; |
| 52 | e->treq = port->disc_addr.treq; |
| 53 | e->portid = port->disc_addr.portid; |
| 54 | /* we support only dynamic controllers */ |
| 55 | e->cntlid = cpu_to_le16(NVME_CNTLID_DYNAMIC); |
| 56 | e->asqsz = cpu_to_le16(NVMF_AQ_DEPTH); |
| 57 | e->nqntype = type; |
| 58 | memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE); |
| 59 | memcpy(e->traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE); |
| 60 | memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE); |
| 61 | memcpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE); |
| 62 | } |
| 63 | |
| 64 | static void nvmet_execute_get_disc_log_page(struct nvmet_req *req) |
| 65 | { |
| 66 | const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry); |
| 67 | struct nvmet_ctrl *ctrl = req->sq->ctrl; |
| 68 | struct nvmf_disc_rsp_page_hdr *hdr; |
| 69 | size_t data_len = nvmet_get_log_page_len(req->cmd); |
| 70 | size_t alloc_len = max(data_len, sizeof(*hdr)); |
| 71 | int residual_len = data_len - sizeof(*hdr); |
| 72 | struct nvmet_subsys_link *p; |
| 73 | struct nvmet_port *r; |
| 74 | u32 numrec = 0; |
| 75 | u16 status = 0; |
| 76 | |
| 77 | /* |
| 78 | * Make sure we're passing at least a buffer of response header size. |
| 79 | * If host provided data len is less than the header size, only the |
| 80 | * number of bytes requested by host will be sent to host. |
| 81 | */ |
| 82 | hdr = kzalloc(alloc_len, GFP_KERNEL); |
| 83 | if (!hdr) { |
| 84 | status = NVME_SC_INTERNAL; |
| 85 | goto out; |
| 86 | } |
| 87 | |
| 88 | down_read(&nvmet_config_sem); |
| 89 | list_for_each_entry(p, &req->port->subsystems, entry) { |
| 90 | if (!nvmet_host_allowed(req, p->subsys, ctrl->hostnqn)) |
| 91 | continue; |
| 92 | if (residual_len >= entry_size) { |
| 93 | nvmet_format_discovery_entry(hdr, req->port, |
| 94 | p->subsys->subsysnqn, |
| 95 | NVME_NQN_NVME, numrec); |
| 96 | residual_len -= entry_size; |
| 97 | } |
| 98 | numrec++; |
| 99 | } |
| 100 | |
| 101 | list_for_each_entry(r, &req->port->referrals, entry) { |
| 102 | if (residual_len >= entry_size) { |
| 103 | nvmet_format_discovery_entry(hdr, r, |
| 104 | NVME_DISC_SUBSYS_NAME, |
| 105 | NVME_NQN_DISC, numrec); |
| 106 | residual_len -= entry_size; |
| 107 | } |
| 108 | numrec++; |
| 109 | } |
| 110 | |
| 111 | hdr->genctr = cpu_to_le64(nvmet_genctr); |
| 112 | hdr->numrec = cpu_to_le64(numrec); |
| 113 | hdr->recfmt = cpu_to_le16(0); |
| 114 | |
| 115 | up_read(&nvmet_config_sem); |
| 116 | |
| 117 | status = nvmet_copy_to_sgl(req, 0, hdr, data_len); |
| 118 | kfree(hdr); |
| 119 | out: |
| 120 | nvmet_req_complete(req, status); |
| 121 | } |
| 122 | |
| 123 | static void nvmet_execute_identify_disc_ctrl(struct nvmet_req *req) |
| 124 | { |
| 125 | struct nvmet_ctrl *ctrl = req->sq->ctrl; |
| 126 | struct nvme_id_ctrl *id; |
| 127 | u16 status = 0; |
| 128 | |
| 129 | id = kzalloc(sizeof(*id), GFP_KERNEL); |
| 130 | if (!id) { |
| 131 | status = NVME_SC_INTERNAL; |
| 132 | goto out; |
| 133 | } |
| 134 | |
| 135 | memset(id->fr, ' ', sizeof(id->fr)); |
| 136 | strncpy((char *)id->fr, UTS_RELEASE, sizeof(id->fr)); |
| 137 | |
| 138 | /* no limit on data transfer sizes for now */ |
| 139 | id->mdts = 0; |
| 140 | id->cntlid = cpu_to_le16(ctrl->cntlid); |
| 141 | id->ver = cpu_to_le32(ctrl->subsys->ver); |
| 142 | id->lpa = (1 << 2); |
| 143 | |
| 144 | /* no enforcement soft-limit for maxcmd - pick arbitrary high value */ |
| 145 | id->maxcmd = cpu_to_le16(NVMET_MAX_CMD); |
| 146 | |
| 147 | id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */ |
| 148 | if (ctrl->ops->has_keyed_sgls) |
| 149 | id->sgls |= cpu_to_le32(1 << 2); |
| 150 | if (ctrl->ops->sqe_inline_size) |
| 151 | id->sgls |= cpu_to_le32(1 << 20); |
| 152 | |
| 153 | strcpy(id->subnqn, ctrl->subsys->subsysnqn); |
| 154 | |
| 155 | status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id)); |
| 156 | |
| 157 | kfree(id); |
| 158 | out: |
| 159 | nvmet_req_complete(req, status); |
| 160 | } |
| 161 | |
| 162 | int nvmet_parse_discovery_cmd(struct nvmet_req *req) |
| 163 | { |
| 164 | struct nvme_command *cmd = req->cmd; |
| 165 | |
| 166 | req->ns = NULL; |
| 167 | |
| 168 | if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) { |
| 169 | pr_err("nvmet: got cmd %d while not ready\n", |
| 170 | cmd->common.opcode); |
| 171 | return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; |
| 172 | } |
| 173 | |
| 174 | switch (cmd->common.opcode) { |
| 175 | case nvme_admin_get_log_page: |
| 176 | req->data_len = nvmet_get_log_page_len(cmd); |
| 177 | |
| 178 | switch (cmd->get_log_page.lid) { |
| 179 | case NVME_LOG_DISC: |
| 180 | req->execute = nvmet_execute_get_disc_log_page; |
| 181 | return 0; |
| 182 | default: |
| 183 | pr_err("nvmet: unsupported get_log_page lid %d\n", |
| 184 | cmd->get_log_page.lid); |
| 185 | return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; |
| 186 | } |
| 187 | case nvme_admin_identify: |
| 188 | req->data_len = 4096; |
| 189 | switch (le32_to_cpu(cmd->identify.cns)) { |
| 190 | case 0x01: |
| 191 | req->execute = |
| 192 | nvmet_execute_identify_disc_ctrl; |
| 193 | return 0; |
| 194 | default: |
| 195 | pr_err("nvmet: unsupported identify cns %d\n", |
| 196 | le32_to_cpu(cmd->identify.cns)); |
| 197 | return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; |
| 198 | } |
| 199 | default: |
| 200 | pr_err("nvmet: unsupported cmd %d\n", |
| 201 | cmd->common.opcode); |
| 202 | return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; |
| 203 | } |
| 204 | |
| 205 | pr_err("nvmet: unhandled cmd %d\n", cmd->common.opcode); |
| 206 | return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; |
| 207 | } |
| 208 | |
| 209 | int __init nvmet_init_discovery(void) |
| 210 | { |
| 211 | nvmet_disc_subsys = |
| 212 | nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_DISC); |
| 213 | if (!nvmet_disc_subsys) |
| 214 | return -ENOMEM; |
| 215 | return 0; |
| 216 | } |
| 217 | |
| 218 | void nvmet_exit_discovery(void) |
| 219 | { |
| 220 | nvmet_subsys_put(nvmet_disc_subsys); |
| 221 | } |