drivers/nvme/target/discovery.c

   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_disc_get_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         if (req->cmd->get_log_page.lid != NVME_LOG_DISC) {
 175                 req->error_loc =
 176                         offsetof(struct nvme_get_log_page_command, lid);
 177                 status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 178                 goto out;
 179         }
 180
 181         /* Spec requires dword aligned offsets */
 182         if (offset & 0x3) {
 183                 status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 184                 goto out;
 185         }
 186
 187         /*
 188          * Make sure we're passing at least a buffer of response header size.
 189          * If host provided data len is less than the header size, only the
 190          * number of bytes requested by host will be sent to host.
 191          */
 192         down_read(&nvmet_config_sem);
 193         alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
 194         buffer = kzalloc(alloc_len, GFP_KERNEL);
 195         if (!buffer) {
 196                 up_read(&nvmet_config_sem);
 197                 status = NVME_SC_INTERNAL;
 198                 goto out;
 199         }
 200
 201         hdr = buffer;
 202         list_for_each_entry(p, &req->port->subsystems, entry) {
 203                 char traddr[NVMF_TRADDR_SIZE];
 204
 205                 if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
 206                         continue;
 207
 208                 nvmet_set_disc_traddr(req, req->port, traddr);
 209                 nvmet_format_discovery_entry(hdr, req->port,
 210                                 p->subsys->subsysnqn, traddr,
 211                                 NVME_NQN_NVME, numrec);
 212                 numrec++;
 213         }
 214
 215         list_for_each_entry(r, &req->port->referrals, entry) {
 216                 nvmet_format_discovery_entry(hdr, r,
 217                                 NVME_DISC_SUBSYS_NAME,
 218                                 r->disc_addr.traddr,
 219                                 NVME_NQN_DISC, numrec);
 220                 numrec++;
 221         }
 222
 223         hdr->genctr = cpu_to_le64(nvmet_genctr);
 224         hdr->numrec = cpu_to_le64(numrec);
 225         hdr->recfmt = cpu_to_le16(0);
 226
 227         nvmet_clear_aen_bit(req, NVME_AEN_BIT_DISC_CHANGE);
 228
 229         up_read(&nvmet_config_sem);
 230
 231         status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
 232         kfree(buffer);
 233 out:
 234         nvmet_req_complete(req, status);
 235 }
 236
 237 static void nvmet_execute_disc_identify(struct nvmet_req *req)
 238 {
 239         struct nvmet_ctrl *ctrl = req->sq->ctrl;
 240         struct nvme_id_ctrl *id;
 241         u16 status = 0;
 242
 243         if (req->cmd->identify.cns != NVME_ID_CNS_CTRL) {
 244                 req->error_loc = offsetof(struct nvme_identify, cns);
 245                 status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 246                 goto out;
 247         }
 248
 249         id = kzalloc(sizeof(*id), GFP_KERNEL);
 250         if (!id) {
 251                 status = NVME_SC_INTERNAL;
 252                 goto out;
 253         }
 254
 255         memset(id->fr, ' ', sizeof(id->fr));
 256         strncpy((char *)id->fr, UTS_RELEASE, sizeof(id->fr));
 257
 258         /* no limit on data transfer sizes for now */
 259         id->mdts = 0;
 260         id->cntlid = cpu_to_le16(ctrl->cntlid);
 261         id->ver = cpu_to_le32(ctrl->subsys->ver);
 262         id->lpa = (1 << 2);
 263
 264         /* no enforcement soft-limit for maxcmd - pick arbitrary high value */
 265         id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
 266
 267         id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
 268         if (ctrl->ops->has_keyed_sgls)
 269                 id->sgls |= cpu_to_le32(1 << 2);
 270         if (req->port->inline_data_size)
 271                 id->sgls |= cpu_to_le32(1 << 20);
 272
 273         id->oaes = cpu_to_le32(NVMET_DISC_AEN_CFG_OPTIONAL);
 274
 275         strlcpy(id->subnqn, ctrl->subsys->subsysnqn, sizeof(id->subnqn));
 276
 277         status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
 278
 279         kfree(id);
 280 out:
 281         nvmet_req_complete(req, status);
 282 }
 283
 284 static void nvmet_execute_disc_set_features(struct nvmet_req *req)
 285 {
 286         u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 287         u16 stat;
 288
 289         switch (cdw10 & 0xff) {
 290         case NVME_FEAT_KATO:
 291                 stat = nvmet_set_feat_kato(req);
 292                 break;
 293         case NVME_FEAT_ASYNC_EVENT:
 294                 stat = nvmet_set_feat_async_event(req,
 295                                                   NVMET_DISC_AEN_CFG_OPTIONAL);
 296                 break;
 297         default:
 298                 req->error_loc =
 299                         offsetof(struct nvme_common_command, cdw10);
 300                 stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 301                 break;
 302         }
 303
 304         nvmet_req_complete(req, stat);
 305 }
 306
 307 static void nvmet_execute_disc_get_features(struct nvmet_req *req)
 308 {
 309         u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 310         u16 stat = 0;
 311
 312         switch (cdw10 & 0xff) {
 313         case NVME_FEAT_KATO:
 314                 nvmet_get_feat_kato(req);
 315                 break;
 316         case NVME_FEAT_ASYNC_EVENT:
 317                 nvmet_get_feat_async_event(req);
 318                 break;
 319         default:
 320                 req->error_loc =
 321                         offsetof(struct nvme_common_command, cdw10);
 322                 stat = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 323                 break;
 324         }
 325
 326         nvmet_req_complete(req, stat);
 327 }
 328
 329 u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
 330 {
 331         struct nvme_command *cmd = req->cmd;
 332
 333         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
 334                 pr_err("got cmd %d while not ready\n",
 335                        cmd->common.opcode);
 336                 req->error_loc =
 337                         offsetof(struct nvme_common_command, opcode);
 338                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 339         }
 340
 341         switch (cmd->common.opcode) {
 342         case nvme_admin_set_features:
 343                 req->execute = nvmet_execute_disc_set_features;
 344                 req->data_len = 0;
 345                 return 0;
 346         case nvme_admin_get_features:
 347                 req->execute = nvmet_execute_disc_get_features;
 348                 req->data_len = 0;
 349                 return 0;
 350         case nvme_admin_async_event:
 351                 req->execute = nvmet_execute_async_event;
 352                 req->data_len = 0;
 353                 return 0;
 354         case nvme_admin_keep_alive:
 355                 req->execute = nvmet_execute_keep_alive;
 356                 req->data_len = 0;
 357                 return 0;
 358         case nvme_admin_get_log_page:
 359                 req->data_len = nvmet_get_log_page_len(cmd);
 360                 req->execute = nvmet_execute_disc_get_log_page;
 361                 return 0;
 362         case nvme_admin_identify:
 363                 req->data_len = NVME_IDENTIFY_DATA_SIZE;
 364                 req->execute = nvmet_execute_disc_identify;
 365                 return 0;
 366         default:
 367                 pr_err("unhandled cmd %d\n", cmd->common.opcode);
 368                 req->error_loc = offsetof(struct nvme_common_command, opcode);
 369                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 370         }
 371
 372 }
 373
 374 int __init nvmet_init_discovery(void)
 375 {
 376         nvmet_disc_subsys =
 377                 nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_DISC);
 378         return PTR_ERR_OR_ZERO(nvmet_disc_subsys);
 379 }
 380
 381 void nvmet_exit_discovery(void)
 382 {
 383         nvmet_subsys_put(nvmet_disc_subsys);
 384 }