drivers/nvme/target/discovery.c

   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 }