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/slab.h>
  37 #include <linux/err.h>
  38 #include <asm/unaligned.h>
  39
  40 #include <scsi/fc/fc_gs.h>
  41
  42 #include <scsi/libfc.h>
  43
  44 #include "fc_libfc.h"
  45
  46 #define FC_DISC_RETRY_LIMIT     3       /* max retries */
  47 #define FC_DISC_RETRY_DELAY     500UL   /* (msecs) delay */
  48
  49 static void fc_disc_gpn_ft_req(struct fc_disc *);
  50 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
  51 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
  52 static void fc_disc_timeout(struct work_struct *);
  53 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
  54 static void fc_disc_restart(struct fc_disc *);
  55
  56 /**
  57  * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
  58  * @disc: The discovery job to stop remote ports on
  59  *
  60  * Locking Note: This function expects that the lport mutex is locked before
  61  * calling it.
  62  */
  63 void fc_disc_stop_rports(struct fc_disc *disc)
  64 {
  65         struct fc_lport *lport;
  66         struct fc_rport_priv *rdata, *next;
  67
  68         lport = disc->lport;
  69
  70         mutex_lock(&disc->disc_mutex);
  71         list_for_each_entry_safe(rdata, next, &disc->rports, peers)
  72                 lport->tt.rport_logoff(rdata);
  73         mutex_unlock(&disc->disc_mutex);
  74 }
  75
  76 /**
  77  * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
  78  * @sp:    The sequence of the RSCN exchange
  79  * @fp:    The RSCN frame
  80  * @lport: The local port that the request will be sent on
  81  *
  82  * Locking Note: This function expects that the disc_mutex is locked
  83  *               before it is called.
  84  */
  85 static void fc_disc_recv_rscn_req(struct fc_seq *sp, struct fc_frame *fp,
  86                                   struct fc_disc *disc)
  87 {
  88         struct fc_lport *lport;
  89         struct fc_els_rscn *rp;
  90         struct fc_els_rscn_page *pp;
  91         struct fc_seq_els_data rjt_data;
  92         unsigned int len;
  93         int redisc = 0;
  94         enum fc_els_rscn_ev_qual ev_qual;
  95         enum fc_els_rscn_addr_fmt fmt;
  96         LIST_HEAD(disc_ports);
  97         struct fc_disc_port *dp, *next;
  98
  99         lport = disc->lport;
 100
 101         FC_DISC_DBG(disc, "Received an RSCN event\n");
 102
 103         /* make sure the frame contains an RSCN message */
 104         rp = fc_frame_payload_get(fp, sizeof(*rp));
 105         if (!rp)
 106                 goto reject;
 107         /* make sure the page length is as expected (4 bytes) */
 108         if (rp->rscn_page_len != sizeof(*pp))
 109                 goto reject;
 110         /* get the RSCN payload length */
 111         len = ntohs(rp->rscn_plen);
 112         if (len < sizeof(*rp))
 113                 goto reject;
 114         /* make sure the frame contains the expected payload */
 115         rp = fc_frame_payload_get(fp, len);
 116         if (!rp)
 117                 goto reject;
 118         /* payload must be a multiple of the RSCN page size */
 119         len -= sizeof(*rp);
 120         if (len % sizeof(*pp))
 121                 goto reject;
 122
 123         for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
 124                 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
 125                 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
 126                 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
 127                 fmt &= ELS_RSCN_ADDR_FMT_MASK;
 128                 /*
 129                  * if we get an address format other than port
 130                  * (area, domain, fabric), then do a full discovery
 131                  */
 132                 switch (fmt) {
 133                 case ELS_ADDR_FMT_PORT:
 134                         FC_DISC_DBG(disc, "Port address format for port "
 135                                     "(%6x)\n", ntoh24(pp->rscn_fid));
 136                         dp = kzalloc(sizeof(*dp), GFP_KERNEL);
 137                         if (!dp) {
 138                                 redisc = 1;
 139                                 break;
 140                         }
 141                         dp->lp = lport;
 142                         dp->port_id = ntoh24(pp->rscn_fid);
 143                         list_add_tail(&dp->peers, &disc_ports);
 144                         break;
 145                 case ELS_ADDR_FMT_AREA:
 146                 case ELS_ADDR_FMT_DOM:
 147                 case ELS_ADDR_FMT_FAB:
 148                 default:
 149                         FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
 150                         redisc = 1;
 151                         break;
 152                 }
 153         }
 154         lport->tt.seq_els_rsp_send(sp, ELS_LS_ACC, NULL);
 155
 156         /*
 157          * If not doing a complete rediscovery, do GPN_ID on
 158          * the individual ports mentioned in the list.
 159          * If any of these get an error, do a full rediscovery.
 160          * In any case, go through the list and free the entries.
 161          */
 162         list_for_each_entry_safe(dp, next, &disc_ports, peers) {
 163                 list_del(&dp->peers);
 164                 if (!redisc)
 165                         redisc = fc_disc_single(lport, dp);
 166                 kfree(dp);
 167         }
 168         if (redisc) {
 169                 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
 170                 fc_disc_restart(disc);
 171         } else {
 172                 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
 173                             "redisc %d state %d in_prog %d\n",
 174                             redisc, lport->state, disc->pending);
 175         }
 176         fc_frame_free(fp);
 177         return;
 178 reject:
 179         FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
 180         rjt_data.fp = NULL;
 181         rjt_data.reason = ELS_RJT_LOGIC;
 182         rjt_data.explan = ELS_EXPL_NONE;
 183         lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
 184         fc_frame_free(fp);
 185 }
 186
 187 /**
 188  * fc_disc_recv_req() - Handle incoming requests
 189  * @sp:    The sequence of the request exchange
 190  * @fp:    The request frame
 191  * @lport: The local port receiving the request
 192  *
 193  * Locking Note: This function is called from the EM and will lock
 194  *               the disc_mutex before calling the handler for the
 195  *               request.
 196  */
 197 static void fc_disc_recv_req(struct fc_seq *sp, struct fc_frame *fp,
 198                              struct fc_lport *lport)
 199 {
 200         u8 op;
 201         struct fc_disc *disc = &lport->disc;
 202
 203         op = fc_frame_payload_op(fp);
 204         switch (op) {
 205         case ELS_RSCN:
 206                 mutex_lock(&disc->disc_mutex);
 207                 fc_disc_recv_rscn_req(sp, fp, disc);
 208                 mutex_unlock(&disc->disc_mutex);
 209                 break;
 210         default:
 211                 FC_DISC_DBG(disc, "Received an unsupported request, "
 212                             "the opcode is (%x)\n", op);
 213                 break;
 214         }
 215 }
 216
 217 /**
 218  * fc_disc_restart() - Restart discovery
 219  * @disc: The discovery object to be restarted
 220  *
 221  * Locking Note: This function expects that the disc mutex
 222  *               is already locked.
 223  */
 224 static void fc_disc_restart(struct fc_disc *disc)
 225 {
 226         if (!disc->disc_callback)
 227                 return;
 228
 229         FC_DISC_DBG(disc, "Restarting discovery\n");
 230
 231         disc->requested = 1;
 232         if (disc->pending)
 233                 return;
 234
 235         /*
 236          * Advance disc_id.  This is an arbitrary non-zero number that will
 237          * match the value in the fc_rport_priv after discovery for all
 238          * freshly-discovered remote ports.  Avoid wrapping to zero.
 239          */
 240         disc->disc_id = (disc->disc_id + 2) | 1;
 241         disc->retry_count = 0;
 242         fc_disc_gpn_ft_req(disc);
 243 }
 244
 245 /**
 246  * fc_disc_start() - Start discovery on a local port
 247  * @lport:         The local port to have discovery started on
 248  * @disc_callback: Callback function to be called when discovery is complete
 249  */
 250 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
 251                                                 enum fc_disc_event),
 252                           struct fc_lport *lport)
 253 {
 254         struct fc_disc *disc = &lport->disc;
 255
 256         /*
 257          * At this point we may have a new disc job or an existing
 258          * one. Either way, let's lock when we make changes to it
 259          * and send the GPN_FT request.
 260          */
 261         mutex_lock(&disc->disc_mutex);
 262         disc->disc_callback = disc_callback;
 263         fc_disc_restart(disc);
 264         mutex_unlock(&disc->disc_mutex);
 265 }
 266
 267 /**
 268  * fc_disc_done() - Discovery has been completed
 269  * @disc:  The discovery context
 270  * @event: The discovery completion status
 271  *
 272  * Locking Note: This function expects that the disc mutex is locked before
 273  * it is called. The discovery callback is then made with the lock released,
 274  * and the lock is re-taken before returning from this function
 275  */
 276 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
 277 {
 278         struct fc_lport *lport = disc->lport;
 279         struct fc_rport_priv *rdata;
 280
 281         FC_DISC_DBG(disc, "Discovery complete\n");
 282
 283         disc->pending = 0;
 284         if (disc->requested) {
 285                 fc_disc_restart(disc);
 286                 return;
 287         }
 288
 289         /*
 290          * Go through all remote ports.  If they were found in the latest
 291          * discovery, reverify or log them in.  Otherwise, log them out.
 292          * Skip ports which were never discovered.  These are the dNS port
 293          * and ports which were created by PLOGI.
 294          */
 295         list_for_each_entry(rdata, &disc->rports, peers) {
 296                 if (!rdata->disc_id)
 297                         continue;
 298                 if (rdata->disc_id == disc->disc_id)
 299                         lport->tt.rport_login(rdata);
 300                 else
 301                         lport->tt.rport_logoff(rdata);
 302         }
 303
 304         mutex_unlock(&disc->disc_mutex);
 305         disc->disc_callback(lport, event);
 306         mutex_lock(&disc->disc_mutex);
 307 }
 308
 309 /**
 310  * fc_disc_error() - Handle error on dNS request
 311  * @disc: The discovery context
 312  * @fp:   The error code encoded as a frame pointer
 313  */
 314 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
 315 {
 316         struct fc_lport *lport = disc->lport;
 317         unsigned long delay = 0;
 318
 319         FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
 320                     PTR_ERR(fp), disc->retry_count,
 321                     FC_DISC_RETRY_LIMIT);
 322
 323         if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
 324                 /*
 325                  * Memory allocation failure, or the exchange timed out,
 326                  * retry after delay.
 327                  */
 328                 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
 329                         /* go ahead and retry */
 330                         if (!fp)
 331                                 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
 332                         else {
 333                                 delay = msecs_to_jiffies(lport->e_d_tov);
 334
 335                                 /* timeout faster first time */
 336                                 if (!disc->retry_count)
 337                                         delay /= 4;
 338                         }
 339                         disc->retry_count++;
 340                         schedule_delayed_work(&disc->disc_work, delay);
 341                 } else
 342                         fc_disc_done(disc, DISC_EV_FAILED);
 343         }
 344 }
 345
 346 /**
 347  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
 348  * @lport: The discovery context
 349  *
 350  * Locking Note: This function expects that the disc_mutex is locked
 351  *               before it is called.
 352  */
 353 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
 354 {
 355         struct fc_frame *fp;
 356         struct fc_lport *lport = disc->lport;
 357
 358         WARN_ON(!fc_lport_test_ready(lport));
 359
 360         disc->pending = 1;
 361         disc->requested = 0;
 362
 363         disc->buf_len = 0;
 364         disc->seq_count = 0;
 365         fp = fc_frame_alloc(lport,
 366                             sizeof(struct fc_ct_hdr) +
 367                             sizeof(struct fc_ns_gid_ft));
 368         if (!fp)
 369                 goto err;
 370
 371         if (lport->tt.elsct_send(lport, 0, fp,
 372                                  FC_NS_GPN_FT,
 373                                  fc_disc_gpn_ft_resp,
 374                                  disc, 3 * lport->r_a_tov))
 375                 return;
 376 err:
 377         fc_disc_error(disc, NULL);
 378 }
 379
 380 /**
 381  * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
 382  * @lport: The local port the GPN_FT was received on
 383  * @buf:   The GPN_FT response buffer
 384  * @len:   The size of response buffer
 385  *
 386  * Goes through the list of IDs and names resulting from a request.
 387  */
 388 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
 389 {
 390         struct fc_lport *lport;
 391         struct fc_gpn_ft_resp *np;
 392         char *bp;
 393         size_t plen;
 394         size_t tlen;
 395         int error = 0;
 396         struct fc_rport_identifiers ids;
 397         struct fc_rport_priv *rdata;
 398
 399         lport = disc->lport;
 400         disc->seq_count++;
 401
 402         /*
 403          * Handle partial name record left over from previous call.
 404          */
 405         bp = buf;
 406         plen = len;
 407         np = (struct fc_gpn_ft_resp *)bp;
 408         tlen = disc->buf_len;
 409         disc->buf_len = 0;
 410         if (tlen) {
 411                 WARN_ON(tlen >= sizeof(*np));
 412                 plen = sizeof(*np) - tlen;
 413                 WARN_ON(plen <= 0);
 414                 WARN_ON(plen >= sizeof(*np));
 415                 if (plen > len)
 416                         plen = len;
 417                 np = &disc->partial_buf;
 418                 memcpy((char *)np + tlen, bp, plen);
 419
 420                 /*
 421                  * Set bp so that the loop below will advance it to the
 422                  * first valid full name element.
 423                  */
 424                 bp -= tlen;
 425                 len += tlen;
 426                 plen += tlen;
 427                 disc->buf_len = (unsigned char) plen;
 428                 if (plen == sizeof(*np))
 429                         disc->buf_len = 0;
 430         }
 431
 432         /*
 433          * Handle full name records, including the one filled from above.
 434          * Normally, np == bp and plen == len, but from the partial case above,
 435          * bp, len describe the overall buffer, and np, plen describe the
 436          * partial buffer, which if would usually be full now.
 437          * After the first time through the loop, things return to "normal".
 438          */
 439         while (plen >= sizeof(*np)) {
 440                 ids.port_id = ntoh24(np->fp_fid);
 441                 ids.port_name = ntohll(np->fp_wwpn);
 442
 443                 if (ids.port_id != fc_host_port_id(lport->host) &&
 444                     ids.port_name != lport->wwpn) {
 445                         rdata = lport->tt.rport_create(lport, ids.port_id);
 446                         if (rdata) {
 447                                 rdata->ids.port_name = ids.port_name;
 448                                 rdata->disc_id = disc->disc_id;
 449                         } else {
 450                                 printk(KERN_WARNING "libfc: Failed to allocate "
 451                                        "memory for the newly discovered port "
 452                                        "(%6x)\n", ids.port_id);
 453                                 error = -ENOMEM;
 454                         }
 455                 }
 456
 457                 if (np->fp_flags & FC_NS_FID_LAST) {
 458                         fc_disc_done(disc, DISC_EV_SUCCESS);
 459                         len = 0;
 460                         break;
 461                 }
 462                 len -= sizeof(*np);
 463                 bp += sizeof(*np);
 464                 np = (struct fc_gpn_ft_resp *)bp;
 465                 plen = len;
 466         }
 467
 468         /*
 469          * Save any partial record at the end of the buffer for next time.
 470          */
 471         if (error == 0 && len > 0 && len < sizeof(*np)) {
 472                 if (np != &disc->partial_buf) {
 473                         FC_DISC_DBG(disc, "Partial buffer remains "
 474                                     "for discovery\n");
 475                         memcpy(&disc->partial_buf, np, len);
 476                 }
 477                 disc->buf_len = (unsigned char) len;
 478         }
 479         return error;
 480 }
 481
 482 /**
 483  * fc_disc_timeout() - Handler for discovery timeouts
 484  * @work: Structure holding discovery context that needs to retry discovery
 485  */
 486 static void fc_disc_timeout(struct work_struct *work)
 487 {
 488         struct fc_disc *disc = container_of(work,
 489                                             struct fc_disc,
 490                                             disc_work.work);
 491         mutex_lock(&disc->disc_mutex);
 492         fc_disc_gpn_ft_req(disc);
 493         mutex_unlock(&disc->disc_mutex);
 494 }
 495
 496 /**
 497  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
 498  * @sp:     The sequence that the GPN_FT response was received on
 499  * @fp:     The GPN_FT response frame
 500  * @lp_arg: The discovery context
 501  *
 502  * Locking Note: This function is called without disc mutex held, and
 503  *               should do all its processing with the mutex held
 504  */
 505 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
 506                                 void *disc_arg)
 507 {
 508         struct fc_disc *disc = disc_arg;
 509         struct fc_ct_hdr *cp;
 510         struct fc_frame_header *fh;
 511         enum fc_disc_event event = DISC_EV_NONE;
 512         unsigned int seq_cnt;
 513         unsigned int len;
 514         int error = 0;
 515
 516         mutex_lock(&disc->disc_mutex);
 517         FC_DISC_DBG(disc, "Received a GPN_FT response\n");
 518
 519         if (IS_ERR(fp)) {
 520                 fc_disc_error(disc, fp);
 521                 mutex_unlock(&disc->disc_mutex);
 522                 return;
 523         }
 524
 525         WARN_ON(!fc_frame_is_linear(fp));       /* buffer must be contiguous */
 526         fh = fc_frame_header_get(fp);
 527         len = fr_len(fp) - sizeof(*fh);
 528         seq_cnt = ntohs(fh->fh_seq_cnt);
 529         if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
 530                 cp = fc_frame_payload_get(fp, sizeof(*cp));
 531                 if (!cp) {
 532                         FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
 533                                     fr_len(fp));
 534                         event = DISC_EV_FAILED;
 535                 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 536
 537                         /* Accepted, parse the response. */
 538                         len -= sizeof(*cp);
 539                         error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
 540                 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 541                         FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
 542                                     "(check zoning)\n", cp->ct_reason,
 543                                     cp->ct_explan);
 544                         event = DISC_EV_FAILED;
 545                         if (cp->ct_reason == FC_FS_RJT_UNABL &&
 546                             cp->ct_explan == FC_FS_EXP_FTNR)
 547                                 event = DISC_EV_SUCCESS;
 548                 } else {
 549                         FC_DISC_DBG(disc, "GPN_FT unexpected response code "
 550                                     "%x\n", ntohs(cp->ct_cmd));
 551                         event = DISC_EV_FAILED;
 552                 }
 553         } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
 554                 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
 555         } else {
 556                 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
 557                             "seq_cnt %x expected %x sof %x eof %x\n",
 558                             seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
 559                 event = DISC_EV_FAILED;
 560         }
 561         if (error)
 562                 fc_disc_error(disc, fp);
 563         else if (event != DISC_EV_NONE)
 564                 fc_disc_done(disc, event);
 565         fc_frame_free(fp);
 566         mutex_unlock(&disc->disc_mutex);
 567 }
 568
 569 /**
 570  * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
 571  * @sp:        The sequence the GPN_ID is on
 572  * @fp:        The response frame
 573  * @rdata_arg: The remote port that sent the GPN_ID response
 574  *
 575  * Locking Note: This function is called without disc mutex held.
 576  */
 577 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
 578                                 void *rdata_arg)
 579 {
 580         struct fc_rport_priv *rdata = rdata_arg;
 581         struct fc_rport_priv *new_rdata;
 582         struct fc_lport *lport;
 583         struct fc_disc *disc;
 584         struct fc_ct_hdr *cp;
 585         struct fc_ns_gid_pn *pn;
 586         u64 port_name;
 587
 588         lport = rdata->local_port;
 589         disc = &lport->disc;
 590
 591         mutex_lock(&disc->disc_mutex);
 592         if (PTR_ERR(fp) == -FC_EX_CLOSED)
 593                 goto out;
 594         if (IS_ERR(fp))
 595                 goto redisc;
 596
 597         cp = fc_frame_payload_get(fp, sizeof(*cp));
 598         if (!cp)
 599                 goto redisc;
 600         if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 601                 if (fr_len(fp) < sizeof(struct fc_frame_header) +
 602                     sizeof(*cp) + sizeof(*pn))
 603                         goto redisc;
 604                 pn = (struct fc_ns_gid_pn *)(cp + 1);
 605                 port_name = get_unaligned_be64(&pn->fn_wwpn);
 606                 if (rdata->ids.port_name == -1)
 607                         rdata->ids.port_name = port_name;
 608                 else if (rdata->ids.port_name != port_name) {
 609                         FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
 610                                     "Port-id %x wwpn %llx\n",
 611                                     rdata->ids.port_id, port_name);
 612                         lport->tt.rport_logoff(rdata);
 613
 614                         new_rdata = lport->tt.rport_create(lport,
 615                                                            rdata->ids.port_id);
 616                         if (new_rdata) {
 617                                 new_rdata->disc_id = disc->disc_id;
 618                                 lport->tt.rport_login(new_rdata);
 619                         }
 620                         goto out;
 621                 }
 622                 rdata->disc_id = disc->disc_id;
 623                 lport->tt.rport_login(rdata);
 624         } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 625                 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
 626                             cp->ct_reason, cp->ct_explan);
 627                 lport->tt.rport_logoff(rdata);
 628         } else {
 629                 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
 630                             ntohs(cp->ct_cmd));
 631 redisc:
 632                 fc_disc_restart(disc);
 633         }
 634 out:
 635         mutex_unlock(&disc->disc_mutex);
 636         kref_put(&rdata->kref, lport->tt.rport_destroy);
 637 }
 638
 639 /**
 640  * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
 641  * @lport: The local port to initiate discovery on
 642  * @rdata: remote port private data
 643  *
 644  * Locking Note: This function expects that the disc_mutex is locked
 645  *               before it is called.
 646  * On failure, an error code is returned.
 647  */
 648 static int fc_disc_gpn_id_req(struct fc_lport *lport,
 649                               struct fc_rport_priv *rdata)
 650 {
 651         struct fc_frame *fp;
 652
 653         fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
 654                             sizeof(struct fc_ns_fid));
 655         if (!fp)
 656                 return -ENOMEM;
 657         if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
 658                                   fc_disc_gpn_id_resp, rdata,
 659                                   3 * lport->r_a_tov))
 660                 return -ENOMEM;
 661         kref_get(&rdata->kref);
 662         return 0;
 663 }
 664
 665 /**
 666  * fc_disc_single() - Discover the directory information for a single target
 667  * @lport: The local port the remote port is associated with
 668  * @dp:    The port to rediscover
 669  *
 670  * Locking Note: This function expects that the disc_mutex is locked
 671  *               before it is called.
 672  */
 673 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
 674 {
 675         struct fc_rport_priv *rdata;
 676
 677         rdata = lport->tt.rport_create(lport, dp->port_id);
 678         if (!rdata)
 679                 return -ENOMEM;
 680         rdata->disc_id = 0;
 681         return fc_disc_gpn_id_req(lport, rdata);
 682 }
 683
 684 /**
 685  * fc_disc_stop() - Stop discovery for a given lport
 686  * @lport: The local port that discovery should stop on
 687  */
 688 void fc_disc_stop(struct fc_lport *lport)
 689 {
 690         struct fc_disc *disc = &lport->disc;
 691
 692         if (disc) {
 693                 cancel_delayed_work_sync(&disc->disc_work);
 694                 fc_disc_stop_rports(disc);
 695         }
 696 }
 697
 698 /**
 699  * fc_disc_stop_final() - Stop discovery for a given lport
 700  * @lport: The lport that discovery should stop on
 701  *
 702  * This function will block until discovery has been
 703  * completely stopped and all rports have been deleted.
 704  */
 705 void fc_disc_stop_final(struct fc_lport *lport)
 706 {
 707         fc_disc_stop(lport);
 708         lport->tt.rport_flush_queue();
 709 }
 710
 711 /**
 712  * fc_disc_init() - Initialize the discovery layer for a local port
 713  * @lport: The local port that needs the discovery layer to be initialized
 714  */
 715 int fc_disc_init(struct fc_lport *lport)
 716 {
 717         struct fc_disc *disc;
 718
 719         if (!lport->tt.disc_start)
 720                 lport->tt.disc_start = fc_disc_start;
 721
 722         if (!lport->tt.disc_stop)
 723                 lport->tt.disc_stop = fc_disc_stop;
 724
 725         if (!lport->tt.disc_stop_final)
 726                 lport->tt.disc_stop_final = fc_disc_stop_final;
 727
 728         if (!lport->tt.disc_recv_req)
 729                 lport->tt.disc_recv_req = fc_disc_recv_req;
 730
 731         disc = &lport->disc;
 732         INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
 733         mutex_init(&disc->disc_mutex);
 734         INIT_LIST_HEAD(&disc->rports);
 735
 736         disc->lport = lport;
 737
 738         return 0;
 739 }
 740 EXPORT_SYMBOL(fc_disc_init);