root/drivers/nvme/target/discovery.c

DEFINITIONS

1. __nvmet_disc_changed
2. nvmet_port_disc_changed
3. __nvmet_subsys_disc_changed
4. nvmet_subsys_disc_changed
5. nvmet_referral_enable
6. nvmet_referral_disable
7. nvmet_format_discovery_entry
8. nvmet_set_disc_traddr
9. discovery_log_entries
10. nvmet_execute_get_disc_log_page
11. nvmet_execute_identify_disc_ctrl
12. nvmet_execute_disc_set_features
13. nvmet_execute_disc_get_features
14. nvmet_parse_discovery_cmd
15. nvmet_init_discovery
16. nvmet_exit_discovery

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Discovery service for the NVMe over Fabrics target.
   4  * Copyright (C) 2016 Intel Corporation. All rights reserved.
   5  */
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7 #include <linux/slab.h>
   8 #include <generated/utsrelease.h>
   9 #include "nvmet.h"
  10 
  11 struct nvmet_subsys *nvmet_disc_subsys;
  12 
  13 static u64 nvmet_genctr;
  14 
  15 static void __nvmet_disc_changed(struct nvmet_port *port,
  16                                  struct nvmet_ctrl *ctrl)
  17 {
  18         if (ctrl->port != port)
  19                 return;
  20 
  21         if (nvmet_aen_bit_disabled(ctrl, NVME_AEN_BIT_DISC_CHANGE))
  22                 return;
  23 
  24         nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
  25                               NVME_AER_NOTICE_DISC_CHANGED, NVME_LOG_DISC);
  26 }
  27 
  28 void nvmet_port_disc_changed(struct nvmet_port *port,
  29                              struct nvmet_subsys *subsys)
  30 {
  31         struct nvmet_ctrl *ctrl;
  32 
  33         lockdep_assert_held(&nvmet_config_sem);
  34         nvmet_genctr++;
  35 
  36         mutex_lock(&nvmet_disc_subsys->lock);
  37         list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
  38                 if (subsys && !nvmet_host_allowed(subsys, ctrl->hostnqn))
  39                         continue;
  40 
  41                 __nvmet_disc_changed(port, ctrl);
  42         }
  43         mutex_unlock(&nvmet_disc_subsys->lock);
  44 
  45         /* If transport can signal change, notify transport */
  46         if (port->tr_ops && port->tr_ops->discovery_chg)
  47                 port->tr_ops->discovery_chg(port);
  48 }
  49 
  50 static void __nvmet_subsys_disc_changed(struct nvmet_port *port,
  51                                         struct nvmet_subsys *subsys,
  52                                         struct nvmet_host *host)
  53 {
  54         struct nvmet_ctrl *ctrl;
  55 
  56         mutex_lock(&nvmet_disc_subsys->lock);
  57         list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
  58                 if (host && strcmp(nvmet_host_name(host), ctrl->hostnqn))
  59                         continue;
  60 
  61                 __nvmet_disc_changed(port, ctrl);
  62         }
  63         mutex_unlock(&nvmet_disc_subsys->lock);
  64 }
  65 
  66 void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
  67                                struct nvmet_host *host)
  68 {
  69         struct nvmet_port *port;
  70         struct nvmet_subsys_link *s;
  71 
  72         nvmet_genctr++;
  73 
  74         list_for_each_entry(port, nvmet_ports, global_entry)
  75                 list_for_each_entry(s, &port->subsystems, entry) {
  76                         if (s->subsys != subsys)
  77                                 continue;
  78                         __nvmet_subsys_disc_changed(port, subsys, host);
  79                 }
  80 }
  81 
  82 void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port)
  83 {
  84         down_write(&nvmet_config_sem);
  85         if (list_empty(&port->entry)) {
  86                 list_add_tail(&port->entry, &parent->referrals);
  87                 port->enabled = true;
  88                 nvmet_port_disc_changed(parent, NULL);
  89         }
  90         up_write(&nvmet_config_sem);
  91 }
  92 
  93 void nvmet_referral_disable(struct nvmet_port *parent, struct nvmet_port *port)
  94 {
  95         down_write(&nvmet_config_sem);
  96         if (!list_empty(&port->entry)) {
  97                 port->enabled = false;
  98                 list_del_init(&port->entry);
  99                 nvmet_port_disc_changed(parent, NULL);
 100         }
 101         up_write(&nvmet_config_sem);
 102 }
 103 
 104 static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr,
 105                 struct nvmet_port *port, char *subsys_nqn, char *traddr,
 106                 u8 type, u32 numrec)
 107 {
 108         struct nvmf_disc_rsp_page_entry *e = &hdr->entries[numrec];
 109 
 110         e->trtype = port->disc_addr.trtype;
 111         e->adrfam = port->disc_addr.adrfam;
 112         e->treq = port->disc_addr.treq;
 113         e->portid = port->disc_addr.portid;
 114         /* we support only dynamic controllers */
 115         e->cntlid = cpu_to_le16(NVME_CNTLID_DYNAMIC);
 116         e->asqsz = cpu_to_le16(NVME_AQ_DEPTH);
 117         e->subtype = type;
 118         memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE);
 119         memcpy(e->traddr, traddr, NVMF_TRADDR_SIZE);
 120         memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE);
 121         strncpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE);
 122 }
 123 
 124 /*
 125  * nvmet_set_disc_traddr - set a correct discovery log entry traddr
 126  *
 127  * IP based transports (e.g RDMA) can listen on "any" ipv4/ipv6 addresses
 128  * (INADDR_ANY or IN6ADDR_ANY_INIT). The discovery log page traddr reply
 129  * must not contain that "any" IP address. If the transport implements
 130  * .disc_traddr, use it. this callback will set the discovery traddr
 131  * from the req->port address in case the port in question listens
 132  * "any" IP address.
 133  */
 134 static void nvmet_set_disc_traddr(struct nvmet_req *req, struct nvmet_port *port,
 135                 char *traddr)
 136 {
 137         if (req->ops->disc_traddr)
 138                 req->ops->disc_traddr(req, port, traddr);
 139         else
 140                 memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
 141 }
 142 
 143 static size_t discovery_log_entries(struct nvmet_req *req)
 144 {
 145         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 146         struct nvmet_subsys_link *p;
 147         struct nvmet_port *r;
 148         size_t entries = 0;
 149 
 150         list_for_each_entry(p, &req->port->subsystems, entry) {
 151                 if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
 152                         continue;
 153                 entries++;
 154         }
 155         list_for_each_entry(r, &req->port->referrals, entry)
 156                 entries++;
 157         return entries;
 158 }
 159 
 160 static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
 161 {
 162         const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
 163         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 164         struct nvmf_disc_rsp_page_hdr *hdr;
 165         u64 offset = nvmet_get_log_page_offset(req->cmd);
 166         size_t data_len = nvmet_get_log_page_len(req->cmd);
 167         size_t alloc_len;
 168         struct nvmet_subsys_link *p;
 169         struct nvmet_port *r;
 170         u32 numrec = 0;
 171         u16 status = 0;
 172         void *buffer;
 173 
 174         /* Spec requires dword aligned offsets */
 175         if (offset & 0x3) {
 176                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 177                 goto out;
 178         }
 179 
 180         /*
 181          * Make sure we're passing at least a buffer of response header size.
 182          * If host provided data len is less than the header size, only the
 183          * number of bytes requested by host will be sent to host.
 184          */
 185         down_read(&nvmet_config_sem);
 186         alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
 187         buffer = kzalloc(alloc_len, GFP_KERNEL);
 188         if (!buffer) {
 189                 up_read(&nvmet_config_sem);
 190                 status = NVME_SC_INTERNAL;
 191                 goto out;
 192         }
 193 
 194         hdr = buffer;
 195         list_for_each_entry(p, &req->port->subsystems, entry) {
 196                 char traddr[NVMF_TRADDR_SIZE];
 197 
 198                 if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
 199                         continue;
 200 
 201                 nvmet_set_disc_traddr(req, req->port, traddr);
 202                 nvmet_format_discovery_entry(hdr, req->port,
 203                                 p->subsys->subsysnqn, traddr,
 204                                 NVME_NQN_NVME, numrec);
 205                 numrec++;
 206         }
 207 
 208         list_for_each_entry(r, &req->port->referrals, entry) {
 209                 nvmet_format_discovery_entry(hdr, r,
 210                                 NVME_DISC_SUBSYS_NAME,
 211                                 r->disc_addr.traddr,
 212                                 NVME_NQN_DISC, numrec);
 213                 numrec++;
 214         }
 215 
 216         hdr->genctr = cpu_to_le64(nvmet_genctr);
 217         hdr->numrec = cpu_to_le64(numrec);
 218         hdr->recfmt = cpu_to_le16(0);
 219 
 220         nvmet_clear_aen_bit(req, NVME_AEN_BIT_DISC_CHANGE);
 221 
 222         up_read(&nvmet_config_sem);
 223 
 224         status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
 225         kfree(buffer);
 226 out:
 227         nvmet_req_complete(req, status);
 228 }
 229 
 230 static void nvmet_execute_identify_disc_ctrl(struct nvmet_req *req)
 231 {
 232         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 233         struct nvme_id_ctrl *id;
 234         u16 status = 0;
 235 
 236         id = kzalloc(sizeof(*id), GFP_KERNEL);
 237         if (!id) {
 238                 status = NVME_SC_INTERNAL;
 239                 goto out;
 240         }
 241 
 242         memset(id->fr, ' ', sizeof(id->fr));
 243         strncpy((char *)id->fr, UTS_RELEASE, sizeof(id->fr));
 244 
 245         /* no limit on data transfer sizes for now */
 246         id->mdts = 0;
 247         id->cntlid = cpu_to_le16(ctrl->cntlid);
 248         id->ver = cpu_to_le32(ctrl->subsys->ver);
 249         id->lpa = (1 << 2);
 250 
 251         /* no enforcement soft-limit for maxcmd - pick arbitrary high value */
 252         id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
 253 
 254         id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
 255         if (ctrl->ops->has_keyed_sgls)
 256                 id->sgls |= cpu_to_le32(1 << 2);
 257         if (req->port->inline_data_size)
 258                 id->sgls |= cpu_to_le32(1 << 20);
 259 
 260         id->oaes = cpu_to_le32(NVMET_DISC_AEN_CFG_OPTIONAL);
 261 
 262         strlcpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
 263 
 264         status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
 265 
 266         kfree(id);
 267 out:
 268         nvmet_req_complete(req, status);
 269 }
 270 
 271 static void nvmet_execute_disc_set_features(struct nvmet_req *req)
 272 {
 273         u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 274         u16 stat;
 275 
 276         switch (cdw10 & 0xff) {
 277         case NVME_FEAT_KATO:
 278                 stat = nvmet_set_feat_kato(req);
 279                 break;
 280         case NVME_FEAT_ASYNC_EVENT:
 281                 stat = nvmet_set_feat_async_event(req,
 282                                                   NVMET_DISC_AEN_CFG_OPTIONAL);
 283                 break;
 284         default:
 285                 req->error_loc =
 286                         offsetof(struct nvme_common_command, cdw10);
 287                 stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 288                 break;
 289         }
 290 
 291         nvmet_req_complete(req, stat);
 292 }
 293 
 294 static void nvmet_execute_disc_get_features(struct nvmet_req *req)
 295 {
 296         u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 297         u16 stat = 0;
 298 
 299         switch (cdw10 & 0xff) {
 300         case NVME_FEAT_KATO:
 301                 nvmet_get_feat_kato(req);
 302                 break;
 303         case NVME_FEAT_ASYNC_EVENT:
 304                 nvmet_get_feat_async_event(req);
 305                 break;
 306         default:
 307                 req->error_loc =
 308                         offsetof(struct nvme_common_command, cdw10);
 309                 stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 310                 break;
 311         }
 312 
 313         nvmet_req_complete(req, stat);
 314 }
 315 
 316 u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
 317 {
 318         struct nvme_command *cmd = req->cmd;
 319 
 320         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
 321                 pr_err("got cmd %d while not ready\n",
 322                        cmd->common.opcode);
 323                 req->error_loc =
 324                         offsetof(struct nvme_common_command, opcode);
 325                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 326         }
 327 
 328         switch (cmd->common.opcode) {
 329         case nvme_admin_set_features:
 330                 req->execute = nvmet_execute_disc_set_features;
 331                 req->data_len = 0;
 332                 return 0;
 333         case nvme_admin_get_features:
 334                 req->execute = nvmet_execute_disc_get_features;
 335                 req->data_len = 0;
 336                 return 0;
 337         case nvme_admin_async_event:
 338                 req->execute = nvmet_execute_async_event;
 339                 req->data_len = 0;
 340                 return 0;
 341         case nvme_admin_keep_alive:
 342                 req->execute = nvmet_execute_keep_alive;
 343                 req->data_len = 0;
 344                 return 0;
 345         case nvme_admin_get_log_page:
 346                 req->data_len = nvmet_get_log_page_len(cmd);
 347 
 348                 switch (cmd->get_log_page.lid) {
 349                 case NVME_LOG_DISC:
 350                         req->execute = nvmet_execute_get_disc_log_page;
 351                         return 0;
 352                 default:
 353                         pr_err("unsupported get_log_page lid %d\n",
 354                                cmd->get_log_page.lid);
 355                         req->error_loc =
 356                                 offsetof(struct nvme_get_log_page_command, lid);
 357                         return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 358                 }
 359         case nvme_admin_identify:
 360                 req->data_len = NVME_IDENTIFY_DATA_SIZE;
 361                 switch (cmd->identify.cns) {
 362                 case NVME_ID_CNS_CTRL:
 363                         req->execute =
 364                                 nvmet_execute_identify_disc_ctrl;
 365                         return 0;
 366                 default:
 367                         pr_err("unsupported identify cns %d\n",
 368                                cmd->identify.cns);
 369                         req->error_loc = offsetof(struct nvme_identify, cns);
 370                         return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 371                 }
 372         default:
 373                 pr_err("unhandled cmd %d\n", cmd->common.opcode);
 374                 req->error_loc = offsetof(struct nvme_common_command, opcode);
 375                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 376         }
 377 
 378 }
 379 
 380 int __init nvmet_init_discovery(void)
 381 {
 382         nvmet_disc_subsys =
 383                 nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_DISC);
 384         return PTR_ERR_OR_ZERO(nvmet_disc_subsys);
 385 }
 386 
 387 void nvmet_exit_discovery(void)
 388 {
 389         nvmet_subsys_put(nvmet_disc_subsys);
 390 }