drivers/scsi/libfc/fc_disc.c

   1 /*
   2  * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  16  *
  17  * Maintained at www.Open-FCoE.org
  18  */
  19
  20 /*
  21  * Target Discovery
  22  *
  23  * This block discovers all FC-4 remote ports, including FCP initiators. It
  24  * also handles RSCN events and re-discovery if necessary.
  25  */
  26
  27 /*
  28  * DISC LOCKING
  29  *
  30  * The disc mutex is can be locked when acquiring rport locks, but may not
  31  * be held when acquiring the lport lock. Refer to fc_lport.c for more
  32  * details.
  33  */
  34
  35 #include <linux/timer.h>
  36 #include <linux/err.h>
  37 #include <asm/unaligned.h>
  38
  39 #include <scsi/fc/fc_gs.h>
  40
  41 #include <scsi/libfc.h>
  42
  43 #define FC_DISC_RETRY_LIMIT     3       /* max retries */
  44 #define FC_DISC_RETRY_DELAY     500UL   /* (msecs) delay */
  45
  46 static void fc_disc_gpn_ft_req(struct fc_disc *);
  47 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
  48 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
  49 static void fc_disc_timeout(struct work_struct *);
  50 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
  51 static void fc_disc_restart(struct fc_disc *);
  52
  53 /**
  54  * fc_disc_stop_rports() - delete all the remote ports associated with the lport
  55  * @disc: The discovery job to stop rports on
  56  *
  57  * Locking Note: This function expects that the lport mutex is locked before
  58  * calling it.
  59  */
  60 void fc_disc_stop_rports(struct fc_disc *disc)
  61 {
  62         struct fc_lport *lport;
  63         struct fc_rport_priv *rdata, *next;
  64
  65         lport = disc->lport;
  66
  67         mutex_lock(&disc->disc_mutex);
  68         list_for_each_entry_safe(rdata, next, &disc->rports, peers)
  69                 lport->tt.rport_logoff(rdata);
  70         mutex_unlock(&disc->disc_mutex);
  71 }
  72
  73 /**
  74  * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
  75  * @sp: Current sequence of the RSCN exchange
  76  * @fp: RSCN Frame
  77  * @lport: Fibre Channel host port instance
  78  *
  79  * Locking Note: This function expects that the disc_mutex is locked
  80  *               before it is called.
  81  */
  82 static void fc_disc_recv_rscn_req(struct fc_seq *sp, struct fc_frame *fp,
  83                                   struct fc_disc *disc)
  84 {
  85         struct fc_lport *lport;
  86         struct fc_els_rscn *rp;
  87         struct fc_els_rscn_page *pp;
  88         struct fc_seq_els_data rjt_data;
  89         unsigned int len;
  90         int redisc = 0;
  91         enum fc_els_rscn_ev_qual ev_qual;
  92         enum fc_els_rscn_addr_fmt fmt;
  93         LIST_HEAD(disc_ports);
  94         struct fc_disc_port *dp, *next;
  95
  96         lport = disc->lport;
  97
  98         FC_DISC_DBG(disc, "Received an RSCN event\n");
  99
 100         /* make sure the frame contains an RSCN message */
 101         rp = fc_frame_payload_get(fp, sizeof(*rp));
 102         if (!rp)
 103                 goto reject;
 104         /* make sure the page length is as expected (4 bytes) */
 105         if (rp->rscn_page_len != sizeof(*pp))
 106                 goto reject;
 107         /* get the RSCN payload length */
 108         len = ntohs(rp->rscn_plen);
 109         if (len < sizeof(*rp))
 110                 goto reject;
 111         /* make sure the frame contains the expected payload */
 112         rp = fc_frame_payload_get(fp, len);
 113         if (!rp)
 114                 goto reject;
 115         /* payload must be a multiple of the RSCN page size */
 116         len -= sizeof(*rp);
 117         if (len % sizeof(*pp))
 118                 goto reject;
 119
 120         for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
 121                 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
 122                 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
 123                 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
 124                 fmt &= ELS_RSCN_ADDR_FMT_MASK;
 125                 /*
 126                  * if we get an address format other than port
 127                  * (area, domain, fabric), then do a full discovery
 128                  */
 129                 switch (fmt) {
 130                 case ELS_ADDR_FMT_PORT:
 131                         FC_DISC_DBG(disc, "Port address format for port "
 132                                     "(%6x)\n", ntoh24(pp->rscn_fid));
 133                         dp = kzalloc(sizeof(*dp), GFP_KERNEL);
 134                         if (!dp) {
 135                                 redisc = 1;
 136                                 break;
 137                         }
 138                         dp->lp = lport;
 139                         dp->port_id = ntoh24(pp->rscn_fid);
 140                         list_add_tail(&dp->peers, &disc_ports);
 141                         break;
 142                 case ELS_ADDR_FMT_AREA:
 143                 case ELS_ADDR_FMT_DOM:
 144                 case ELS_ADDR_FMT_FAB:
 145                 default:
 146                         FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
 147                         redisc = 1;
 148                         break;
 149                 }
 150         }
 151         lport->tt.seq_els_rsp_send(sp, ELS_LS_ACC, NULL);
 152
 153         /*
 154          * If not doing a complete rediscovery, do GPN_ID on
 155          * the individual ports mentioned in the list.
 156          * If any of these get an error, do a full rediscovery.
 157          * In any case, go through the list and free the entries.
 158          */
 159         list_for_each_entry_safe(dp, next, &disc_ports, peers) {
 160                 list_del(&dp->peers);
 161                 if (!redisc)
 162                         redisc = fc_disc_single(lport, dp);
 163                 kfree(dp);
 164         }
 165         if (redisc) {
 166                 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
 167                 fc_disc_restart(disc);
 168         } else {
 169                 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
 170                             "redisc %d state %d in_prog %d\n",
 171                             redisc, lport->state, disc->pending);
 172         }
 173         fc_frame_free(fp);
 174         return;
 175 reject:
 176         FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
 177         rjt_data.fp = NULL;
 178         rjt_data.reason = ELS_RJT_LOGIC;
 179         rjt_data.explan = ELS_EXPL_NONE;
 180         lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
 181         fc_frame_free(fp);
 182 }
 183
 184 /**
 185  * fc_disc_recv_req() - Handle incoming requests
 186  * @sp: Current sequence of the request exchange
 187  * @fp: The frame
 188  * @lport: The FC local port
 189  *
 190  * Locking Note: This function is called from the EM and will lock
 191  *               the disc_mutex before calling the handler for the
 192  *               request.
 193  */
 194 static void fc_disc_recv_req(struct fc_seq *sp, struct fc_frame *fp,
 195                              struct fc_lport *lport)
 196 {
 197         u8 op;
 198         struct fc_disc *disc = &lport->disc;
 199
 200         op = fc_frame_payload_op(fp);
 201         switch (op) {
 202         case ELS_RSCN:
 203                 mutex_lock(&disc->disc_mutex);
 204                 fc_disc_recv_rscn_req(sp, fp, disc);
 205                 mutex_unlock(&disc->disc_mutex);
 206                 break;
 207         default:
 208                 FC_DISC_DBG(disc, "Received an unsupported request, "
 209                             "the opcode is (%x)\n", op);
 210                 break;
 211         }
 212 }
 213
 214 /**
 215  * fc_disc_restart() - Restart discovery
 216  * @lport: FC discovery context
 217  *
 218  * Locking Note: This function expects that the disc mutex
 219  *               is already locked.
 220  */
 221 static void fc_disc_restart(struct fc_disc *disc)
 222 {
 223         if (!disc->disc_callback)
 224                 return;
 225
 226         FC_DISC_DBG(disc, "Restarting discovery\n");
 227
 228         disc->requested = 1;
 229         if (disc->pending)
 230                 return;
 231
 232         /*
 233          * Advance disc_id.  This is an arbitrary non-zero number that will
 234          * match the value in the fc_rport_priv after discovery for all
 235          * freshly-discovered remote ports.  Avoid wrapping to zero.
 236          */
 237         disc->disc_id = (disc->disc_id + 2) | 1;
 238         disc->retry_count = 0;
 239         fc_disc_gpn_ft_req(disc);
 240 }
 241
 242 /**
 243  * fc_disc_start() - Fibre Channel Target discovery
 244  * @lport: FC local port
 245  * @disc_callback: function to be called when discovery is complete
 246  */
 247 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
 248                                                 enum fc_disc_event),
 249                           struct fc_lport *lport)
 250 {
 251         struct fc_disc *disc = &lport->disc;
 252
 253         /*
 254          * At this point we may have a new disc job or an existing
 255          * one. Either way, let's lock when we make changes to it
 256          * and send the GPN_FT request.
 257          */
 258         mutex_lock(&disc->disc_mutex);
 259         disc->disc_callback = disc_callback;
 260         fc_disc_restart(disc);
 261         mutex_unlock(&disc->disc_mutex);
 262 }
 263
 264 /**
 265  * fc_disc_done() - Discovery has been completed
 266  * @disc: FC discovery context
 267  * @event: discovery completion status
 268  *
 269  * Locking Note: This function expects that the disc mutex is locked before
 270  * it is called. The discovery callback is then made with the lock released,
 271  * and the lock is re-taken before returning from this function
 272  */
 273 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
 274 {
 275         struct fc_lport *lport = disc->lport;
 276         struct fc_rport_priv *rdata;
 277
 278         FC_DISC_DBG(disc, "Discovery complete\n");
 279
 280         disc->pending = 0;
 281         if (disc->requested) {
 282                 fc_disc_restart(disc);
 283                 return;
 284         }
 285
 286         /*
 287          * Go through all remote ports.  If they were found in the latest
 288          * discovery, reverify or log them in.  Otherwise, log them out.
 289          * Skip ports which were never discovered.  These are the dNS port
 290          * and ports which were created by PLOGI.
 291          */
 292         list_for_each_entry(rdata, &disc->rports, peers) {
 293                 if (!rdata->disc_id)
 294                         continue;
 295                 if (rdata->disc_id == disc->disc_id)
 296                         lport->tt.rport_login(rdata);
 297                 else
 298                         lport->tt.rport_logoff(rdata);
 299         }
 300
 301         mutex_unlock(&disc->disc_mutex);
 302         disc->disc_callback(lport, event);
 303         mutex_lock(&disc->disc_mutex);
 304 }
 305
 306 /**
 307  * fc_disc_error() - Handle error on dNS request
 308  * @disc: FC discovery context
 309  * @fp: The frame pointer
 310  */
 311 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
 312 {
 313         struct fc_lport *lport = disc->lport;
 314         unsigned long delay = 0;
 315
 316         FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
 317                     PTR_ERR(fp), disc->retry_count,
 318                     FC_DISC_RETRY_LIMIT);
 319
 320         if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
 321                 /*
 322                  * Memory allocation failure, or the exchange timed out,
 323                  * retry after delay.
 324                  */
 325                 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
 326                         /* go ahead and retry */
 327                         if (!fp)
 328                                 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
 329                         else {
 330                                 delay = msecs_to_jiffies(lport->e_d_tov);
 331
 332                                 /* timeout faster first time */
 333                                 if (!disc->retry_count)
 334                                         delay /= 4;
 335                         }
 336                         disc->retry_count++;
 337                         schedule_delayed_work(&disc->disc_work, delay);
 338                 } else
 339                         fc_disc_done(disc, DISC_EV_FAILED);
 340         }
 341 }
 342
 343 /**
 344  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
 345  * @lport: FC discovery context
 346  *
 347  * Locking Note: This function expects that the disc_mutex is locked
 348  *               before it is called.
 349  */
 350 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
 351 {
 352         struct fc_frame *fp;
 353         struct fc_lport *lport = disc->lport;
 354
 355         WARN_ON(!fc_lport_test_ready(lport));
 356
 357         disc->pending = 1;
 358         disc->requested = 0;
 359
 360         disc->buf_len = 0;
 361         disc->seq_count = 0;
 362         fp = fc_frame_alloc(lport,
 363                             sizeof(struct fc_ct_hdr) +
 364                             sizeof(struct fc_ns_gid_ft));
 365         if (!fp)
 366                 goto err;
 367
 368         if (lport->tt.elsct_send(lport, 0, fp,
 369                                  FC_NS_GPN_FT,
 370                                  fc_disc_gpn_ft_resp,
 371                                  disc, lport->e_d_tov))
 372                 return;
 373 err:
 374         fc_disc_error(disc, fp);
 375 }
 376
 377 /**
 378  * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
 379  * @lport: Fibre Channel host port instance
 380  * @buf: GPN_FT response buffer
 381  * @len: size of response buffer
 382  *
 383  * Goes through the list of IDs and names resulting from a request.
 384  */
 385 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
 386 {
 387         struct fc_lport *lport;
 388         struct fc_gpn_ft_resp *np;
 389         char *bp;
 390         size_t plen;
 391         size_t tlen;
 392         int error = 0;
 393         struct fc_rport_identifiers ids;
 394         struct fc_rport_priv *rdata;
 395
 396         lport = disc->lport;
 397         disc->seq_count++;
 398
 399         /*
 400          * Handle partial name record left over from previous call.
 401          */
 402         bp = buf;
 403         plen = len;
 404         np = (struct fc_gpn_ft_resp *)bp;
 405         tlen = disc->buf_len;
 406         disc->buf_len = 0;
 407         if (tlen) {
 408                 WARN_ON(tlen >= sizeof(*np));
 409                 plen = sizeof(*np) - tlen;
 410                 WARN_ON(plen <= 0);
 411                 WARN_ON(plen >= sizeof(*np));
 412                 if (plen > len)
 413                         plen = len;
 414                 np = &disc->partial_buf;
 415                 memcpy((char *)np + tlen, bp, plen);
 416
 417                 /*
 418                  * Set bp so that the loop below will advance it to the
 419                  * first valid full name element.
 420                  */
 421                 bp -= tlen;
 422                 len += tlen;
 423                 plen += tlen;
 424                 disc->buf_len = (unsigned char) plen;
 425                 if (plen == sizeof(*np))
 426                         disc->buf_len = 0;
 427         }
 428
 429         /*
 430          * Handle full name records, including the one filled from above.
 431          * Normally, np == bp and plen == len, but from the partial case above,
 432          * bp, len describe the overall buffer, and np, plen describe the
 433          * partial buffer, which if would usually be full now.
 434          * After the first time through the loop, things return to "normal".
 435          */
 436         while (plen >= sizeof(*np)) {
 437                 ids.port_id = ntoh24(np->fp_fid);
 438                 ids.port_name = ntohll(np->fp_wwpn);
 439
 440                 if (ids.port_id != fc_host_port_id(lport->host) &&
 441                     ids.port_name != lport->wwpn) {
 442                         rdata = lport->tt.rport_create(lport, ids.port_id);
 443                         if (rdata) {
 444                                 rdata->ids.port_name = ids.port_name;
 445                                 rdata->disc_id = disc->disc_id;
 446                         } else {
 447                                 printk(KERN_WARNING "libfc: Failed to allocate "
 448                                        "memory for the newly discovered port "
 449                                        "(%6x)\n", ids.port_id);
 450                                 error = -ENOMEM;
 451                         }
 452                 }
 453
 454                 if (np->fp_flags & FC_NS_FID_LAST) {
 455                         fc_disc_done(disc, DISC_EV_SUCCESS);
 456                         len = 0;
 457                         break;
 458                 }
 459                 len -= sizeof(*np);
 460                 bp += sizeof(*np);
 461                 np = (struct fc_gpn_ft_resp *)bp;
 462                 plen = len;
 463         }
 464
 465         /*
 466          * Save any partial record at the end of the buffer for next time.
 467          */
 468         if (error == 0 && len > 0 && len < sizeof(*np)) {
 469                 if (np != &disc->partial_buf) {
 470                         FC_DISC_DBG(disc, "Partial buffer remains "
 471                                     "for discovery\n");
 472                         memcpy(&disc->partial_buf, np, len);
 473                 }
 474                 disc->buf_len = (unsigned char) len;
 475         }
 476         return error;
 477 }
 478
 479 /**
 480  * fc_disc_timeout() - Retry handler for the disc component
 481  * @work: Structure holding disc obj that needs retry discovery
 482  *
 483  * Handle retry of memory allocation for remote ports.
 484  */
 485 static void fc_disc_timeout(struct work_struct *work)
 486 {
 487         struct fc_disc *disc = container_of(work,
 488                                             struct fc_disc,
 489                                             disc_work.work);
 490         mutex_lock(&disc->disc_mutex);
 491         fc_disc_gpn_ft_req(disc);
 492         mutex_unlock(&disc->disc_mutex);
 493 }
 494
 495 /**
 496  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
 497  * @sp: Current sequence of GPN_FT exchange
 498  * @fp: response frame
 499  * @lp_arg: Fibre Channel host port instance
 500  *
 501  * Locking Note: This function is called without disc mutex held, and
 502  *               should do all its processing with the mutex held
 503  */
 504 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
 505                                 void *disc_arg)
 506 {
 507         struct fc_disc *disc = disc_arg;
 508         struct fc_ct_hdr *cp;
 509         struct fc_frame_header *fh;
 510         enum fc_disc_event event = DISC_EV_NONE;
 511         unsigned int seq_cnt;
 512         unsigned int len;
 513         int error = 0;
 514
 515         mutex_lock(&disc->disc_mutex);
 516         FC_DISC_DBG(disc, "Received a GPN_FT response\n");
 517
 518         if (IS_ERR(fp)) {
 519                 fc_disc_error(disc, fp);
 520                 mutex_unlock(&disc->disc_mutex);
 521                 return;
 522         }
 523
 524         WARN_ON(!fc_frame_is_linear(fp));       /* buffer must be contiguous */
 525         fh = fc_frame_header_get(fp);
 526         len = fr_len(fp) - sizeof(*fh);
 527         seq_cnt = ntohs(fh->fh_seq_cnt);
 528         if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
 529                 cp = fc_frame_payload_get(fp, sizeof(*cp));
 530                 if (!cp) {
 531                         FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
 532                                     fr_len(fp));
 533                         event = DISC_EV_FAILED;
 534                 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 535
 536                         /* Accepted, parse the response. */
 537                         len -= sizeof(*cp);
 538                         error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
 539                 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 540                         FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
 541                                     "(check zoning)\n", cp->ct_reason,
 542                                     cp->ct_explan);
 543                         event = DISC_EV_FAILED;
 544                         if (cp->ct_reason == FC_FS_RJT_UNABL &&
 545                             cp->ct_explan == FC_FS_EXP_FTNR)
 546                                 event = DISC_EV_SUCCESS;
 547                 } else {
 548                         FC_DISC_DBG(disc, "GPN_FT unexpected response code "
 549                                     "%x\n", ntohs(cp->ct_cmd));
 550                         event = DISC_EV_FAILED;
 551                 }
 552         } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
 553                 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
 554         } else {
 555                 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
 556                             "seq_cnt %x expected %x sof %x eof %x\n",
 557                             seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
 558                 event = DISC_EV_FAILED;
 559         }
 560         if (error)
 561                 fc_disc_error(disc, fp);
 562         else if (event != DISC_EV_NONE)
 563                 fc_disc_done(disc, event);
 564         fc_frame_free(fp);
 565         mutex_unlock(&disc->disc_mutex);
 566 }
 567
 568 /**
 569  * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
 570  * @sp: exchange sequence
 571  * @fp: response frame
 572  * @rdata_arg: remote port private data
 573  *
 574  * Locking Note: This function is called without disc mutex held.
 575  */
 576 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
 577                                 void *rdata_arg)
 578 {
 579         struct fc_rport_priv *rdata = rdata_arg;
 580         struct fc_rport_priv *new_rdata;
 581         struct fc_lport *lport;
 582         struct fc_disc *disc;
 583         struct fc_ct_hdr *cp;
 584         struct fc_ns_gid_pn *pn;
 585         u64 port_name;
 586
 587         lport = rdata->local_port;
 588         disc = &lport->disc;
 589
 590         mutex_lock(&disc->disc_mutex);
 591         if (PTR_ERR(fp) == -FC_EX_CLOSED)
 592                 goto out;
 593         if (IS_ERR(fp))
 594                 goto redisc;
 595
 596         cp = fc_frame_payload_get(fp, sizeof(*cp));
 597         if (!cp)
 598                 goto redisc;
 599         if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 600                 if (fr_len(fp) < sizeof(struct fc_frame_header) +
 601                     sizeof(*cp) + sizeof(*pn))
 602                         goto redisc;
 603                 pn = (struct fc_ns_gid_pn *)(cp + 1);
 604                 port_name = get_unaligned_be64(&pn->fn_wwpn);
 605                 if (rdata->ids.port_name == -1)
 606                         rdata->ids.port_name = port_name;
 607                 else if (rdata->ids.port_name != port_name) {
 608                         FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
 609                                     "Port-id %x wwpn %llx\n",
 610                                     rdata->ids.port_id, port_name);
 611                         lport->tt.rport_logoff(rdata);
 612
 613                         new_rdata = lport->tt.rport_create(lport,
 614                                                            rdata->ids.port_id);
 615                         if (new_rdata) {
 616                                 new_rdata->disc_id = disc->disc_id;
 617                                 lport->tt.rport_login(new_rdata);
 618                         }
 619                         goto out;
 620                 }
 621                 rdata->disc_id = disc->disc_id;
 622                 lport->tt.rport_login(rdata);
 623         } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 624                 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
 625                             cp->ct_reason, cp->ct_explan);
 626                 lport->tt.rport_logoff(rdata);
 627         } else {
 628                 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
 629                             ntohs(cp->ct_cmd));
 630 redisc:
 631                 fc_disc_restart(disc);
 632         }
 633 out:
 634         mutex_unlock(&disc->disc_mutex);
 635         kref_put(&rdata->kref, lport->tt.rport_destroy);
 636 }
 637
 638 /**
 639  * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
 640  * @lport: local port
 641  * @rdata: remote port private data
 642  *
 643  * Locking Note: This function expects that the disc_mutex is locked
 644  *               before it is called.
 645  * On failure, an error code is returned.
 646  */
 647 static int fc_disc_gpn_id_req(struct fc_lport *lport,
 648                               struct fc_rport_priv *rdata)
 649 {
 650         struct fc_frame *fp;
 651
 652         fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
 653                             sizeof(struct fc_ns_fid));
 654         if (!fp)
 655                 return -ENOMEM;
 656         if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
 657                                  fc_disc_gpn_id_resp, rdata, lport->e_d_tov))
 658                 return -ENOMEM;
 659         kref_get(&rdata->kref);
 660         return 0;
 661 }
 662
 663 /**
 664  * fc_disc_single() - Discover the directory information for a single target
 665  * @lport: local port
 666  * @dp: The port to rediscover
 667  *
 668  * Locking Note: This function expects that the disc_mutex is locked
 669  *               before it is called.
 670  */
 671 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
 672 {
 673         struct fc_rport_priv *rdata;
 674
 675         rdata = lport->tt.rport_create(lport, dp->port_id);
 676         if (!rdata)
 677                 return -ENOMEM;
 678         rdata->disc_id = 0;
 679         return fc_disc_gpn_id_req(lport, rdata);
 680 }
 681
 682 /**
 683  * fc_disc_stop() - Stop discovery for a given lport
 684  * @lport: The lport that discovery should stop for
 685  */
 686 void fc_disc_stop(struct fc_lport *lport)
 687 {
 688         struct fc_disc *disc = &lport->disc;
 689
 690         if (disc) {
 691                 cancel_delayed_work_sync(&disc->disc_work);
 692                 fc_disc_stop_rports(disc);
 693         }
 694 }
 695
 696 /**
 697  * fc_disc_stop_final() - Stop discovery for a given lport
 698  * @lport: The lport that discovery should stop for
 699  *
 700  * This function will block until discovery has been
 701  * completely stopped and all rports have been deleted.
 702  */
 703 void fc_disc_stop_final(struct fc_lport *lport)
 704 {
 705         fc_disc_stop(lport);
 706         lport->tt.rport_flush_queue();
 707 }
 708
 709 /**
 710  * fc_disc_init() - Initialize the discovery block
 711  * @lport: FC local port
 712  */
 713 int fc_disc_init(struct fc_lport *lport)
 714 {
 715         struct fc_disc *disc;
 716
 717         if (!lport->tt.disc_start)
 718                 lport->tt.disc_start = fc_disc_start;
 719
 720         if (!lport->tt.disc_stop)
 721                 lport->tt.disc_stop = fc_disc_stop;
 722
 723         if (!lport->tt.disc_stop_final)
 724                 lport->tt.disc_stop_final = fc_disc_stop_final;
 725
 726         if (!lport->tt.disc_recv_req)
 727                 lport->tt.disc_recv_req = fc_disc_recv_req;
 728
 729         disc = &lport->disc;
 730         INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
 731         mutex_init(&disc->disc_mutex);
 732         INIT_LIST_HEAD(&disc->rports);
 733
 734         disc->lport = lport;
 735
 736         return 0;
 737 }
 738 EXPORT_SYMBOL(fc_disc_init);