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 #define FC_DISC_DELAY           3
  47
  48 static int fc_disc_debug;
  49
  50 #define FC_DEBUG_DISC(fmt...)                   \
  51         do {                                    \
  52                 if (fc_disc_debug)              \
  53                         FC_DBG(fmt);            \
  54         } while (0)
  55
  56 static void fc_disc_gpn_ft_req(struct fc_disc *);
  57 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
  58 static int fc_disc_new_target(struct fc_disc *, struct fc_rport *,
  59                               struct fc_rport_identifiers *);
  60 static void fc_disc_del_target(struct fc_disc *, struct fc_rport *);
  61 static void fc_disc_done(struct fc_disc *);
  62 static void fc_disc_timeout(struct work_struct *);
  63 static void fc_disc_single(struct fc_disc *, struct fc_disc_port *);
  64 static void fc_disc_restart(struct fc_disc *);
  65
  66 /**
  67  * fc_disc_lookup_rport() - lookup a remote port by port_id
  68  * @lport: Fibre Channel host port instance
  69  * @port_id: remote port port_id to match
  70  */
  71 struct fc_rport *fc_disc_lookup_rport(const struct fc_lport *lport,
  72                                       u32 port_id)
  73 {
  74         const struct fc_disc *disc = &lport->disc;
  75         struct fc_rport *rport, *found = NULL;
  76         struct fc_rport_libfc_priv *rdata;
  77         int disc_found = 0;
  78
  79         list_for_each_entry(rdata, &disc->rports, peers) {
  80                 rport = PRIV_TO_RPORT(rdata);
  81                 if (rport->port_id == port_id) {
  82                         disc_found = 1;
  83                         found = rport;
  84                         break;
  85                 }
  86         }
  87
  88         if (!disc_found)
  89                 found = NULL;
  90
  91         return found;
  92 }
  93
  94 /**
  95  * fc_disc_stop_rports() - delete all the remote ports associated with the lport
  96  * @disc: The discovery job to stop rports on
  97  *
  98  * Locking Note: This function expects that the lport mutex is locked before
  99  * calling it.
 100  */
 101 void fc_disc_stop_rports(struct fc_disc *disc)
 102 {
 103         struct fc_lport *lport;
 104         struct fc_rport *rport;
 105         struct fc_rport_libfc_priv *rdata, *next;
 106
 107         lport = disc->lport;
 108
 109         mutex_lock(&disc->disc_mutex);
 110         list_for_each_entry_safe(rdata, next, &disc->rports, peers) {
 111                 rport = PRIV_TO_RPORT(rdata);
 112                 list_del(&rdata->peers);
 113                 lport->tt.rport_logoff(rport);
 114         }
 115
 116         list_for_each_entry_safe(rdata, next, &disc->rogue_rports, peers) {
 117                 rport = PRIV_TO_RPORT(rdata);
 118                 lport->tt.rport_logoff(rport);
 119         }
 120
 121         mutex_unlock(&disc->disc_mutex);
 122 }
 123
 124 /**
 125  * fc_disc_rport_callback() - Event handler for rport events
 126  * @lport: The lport which is receiving the event
 127  * @rport: The rport which the event has occured on
 128  * @event: The event that occured
 129  *
 130  * Locking Note: The rport lock should not be held when calling
 131  *               this function.
 132  */
 133 static void fc_disc_rport_callback(struct fc_lport *lport,
 134                                    struct fc_rport *rport,
 135                                    enum fc_rport_event event)
 136 {
 137         struct fc_rport_libfc_priv *rdata = rport->dd_data;
 138         struct fc_disc *disc = &lport->disc;
 139
 140         FC_DEBUG_DISC("Received a %d event for port (%6x)\n", event,
 141                       rport->port_id);
 142
 143         switch (event) {
 144         case RPORT_EV_CREATED:
 145                 if (disc) {
 146                         mutex_lock(&disc->disc_mutex);
 147                         list_add_tail(&rdata->peers, &disc->rports);
 148                         mutex_unlock(&disc->disc_mutex);
 149                 }
 150                 break;
 151         case RPORT_EV_LOGO:
 152         case RPORT_EV_FAILED:
 153         case RPORT_EV_STOP:
 154                 mutex_lock(&disc->disc_mutex);
 155                 mutex_lock(&rdata->rp_mutex);
 156                 if (rdata->trans_state == FC_PORTSTATE_ROGUE)
 157                         list_del(&rdata->peers);
 158                 mutex_unlock(&rdata->rp_mutex);
 159                 mutex_unlock(&disc->disc_mutex);
 160                 break;
 161         default:
 162                 break;
 163         }
 164
 165 }
 166
 167 /**
 168  * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
 169  * @sp: Current sequence of the RSCN exchange
 170  * @fp: RSCN Frame
 171  * @lport: Fibre Channel host port instance
 172  *
 173  * Locking Note: This function expects that the disc_mutex is locked
 174  *               before it is called.
 175  */
 176 static void fc_disc_recv_rscn_req(struct fc_seq *sp, struct fc_frame *fp,
 177                                   struct fc_disc *disc)
 178 {
 179         struct fc_lport *lport;
 180         struct fc_rport *rport;
 181         struct fc_rport_libfc_priv *rdata;
 182         struct fc_els_rscn *rp;
 183         struct fc_els_rscn_page *pp;
 184         struct fc_seq_els_data rjt_data;
 185         unsigned int len;
 186         int redisc = 0;
 187         enum fc_els_rscn_ev_qual ev_qual;
 188         enum fc_els_rscn_addr_fmt fmt;
 189         LIST_HEAD(disc_ports);
 190         struct fc_disc_port *dp, *next;
 191
 192         lport = disc->lport;
 193
 194         FC_DEBUG_DISC("Received an RSCN event on port (%6x)\n",
 195                       fc_host_port_id(lport->host));
 196
 197         /* make sure the frame contains an RSCN message */
 198         rp = fc_frame_payload_get(fp, sizeof(*rp));
 199         if (!rp)
 200                 goto reject;
 201         /* make sure the page length is as expected (4 bytes) */
 202         if (rp->rscn_page_len != sizeof(*pp))
 203                 goto reject;
 204         /* get the RSCN payload length */
 205         len = ntohs(rp->rscn_plen);
 206         if (len < sizeof(*rp))
 207                 goto reject;
 208         /* make sure the frame contains the expected payload */
 209         rp = fc_frame_payload_get(fp, len);
 210         if (!rp)
 211                 goto reject;
 212         /* payload must be a multiple of the RSCN page size */
 213         len -= sizeof(*rp);
 214         if (len % sizeof(*pp))
 215                 goto reject;
 216
 217         for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
 218                 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
 219                 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
 220                 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
 221                 fmt &= ELS_RSCN_ADDR_FMT_MASK;
 222                 /*
 223                  * if we get an address format other than port
 224                  * (area, domain, fabric), then do a full discovery
 225                  */
 226                 switch (fmt) {
 227                 case ELS_ADDR_FMT_PORT:
 228                         FC_DEBUG_DISC("Port address format for port (%6x)\n",
 229                                       ntoh24(pp->rscn_fid));
 230                         dp = kzalloc(sizeof(*dp), GFP_KERNEL);
 231                         if (!dp) {
 232                                 redisc = 1;
 233                                 break;
 234                         }
 235                         dp->lp = lport;
 236                         dp->ids.port_id = ntoh24(pp->rscn_fid);
 237                         dp->ids.port_name = -1;
 238                         dp->ids.node_name = -1;
 239                         dp->ids.roles = FC_RPORT_ROLE_UNKNOWN;
 240                         list_add_tail(&dp->peers, &disc_ports);
 241                         break;
 242                 case ELS_ADDR_FMT_AREA:
 243                 case ELS_ADDR_FMT_DOM:
 244                 case ELS_ADDR_FMT_FAB:
 245                 default:
 246                         FC_DEBUG_DISC("Address format is (%d)\n", fmt);
 247                         redisc = 1;
 248                         break;
 249                 }
 250         }
 251         lport->tt.seq_els_rsp_send(sp, ELS_LS_ACC, NULL);
 252         if (redisc) {
 253                 FC_DEBUG_DISC("RSCN received: rediscovering\n");
 254                 fc_disc_restart(disc);
 255         } else {
 256                 FC_DEBUG_DISC("RSCN received: not rediscovering. "
 257                               "redisc %d state %d in_prog %d\n",
 258                               redisc, lport->state, disc->pending);
 259                 list_for_each_entry_safe(dp, next, &disc_ports, peers) {
 260                         list_del(&dp->peers);
 261                         rport = lport->tt.rport_lookup(lport, dp->ids.port_id);
 262                         if (rport) {
 263                                 rdata = rport->dd_data;
 264                                 list_del(&rdata->peers);
 265                                 lport->tt.rport_logoff(rport);
 266                         }
 267                         fc_disc_single(disc, dp);
 268                 }
 269         }
 270         fc_frame_free(fp);
 271         return;
 272 reject:
 273         FC_DEBUG_DISC("Received a bad RSCN frame\n");
 274         rjt_data.fp = NULL;
 275         rjt_data.reason = ELS_RJT_LOGIC;
 276         rjt_data.explan = ELS_EXPL_NONE;
 277         lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
 278         fc_frame_free(fp);
 279 }
 280
 281 /**
 282  * fc_disc_recv_req() - Handle incoming requests
 283  * @sp: Current sequence of the request exchange
 284  * @fp: The frame
 285  * @lport: The FC local port
 286  *
 287  * Locking Note: This function is called from the EM and will lock
 288  *               the disc_mutex before calling the handler for the
 289  *               request.
 290  */
 291 static void fc_disc_recv_req(struct fc_seq *sp, struct fc_frame *fp,
 292                              struct fc_lport *lport)
 293 {
 294         u8 op;
 295         struct fc_disc *disc = &lport->disc;
 296
 297         op = fc_frame_payload_op(fp);
 298         switch (op) {
 299         case ELS_RSCN:
 300                 mutex_lock(&disc->disc_mutex);
 301                 fc_disc_recv_rscn_req(sp, fp, disc);
 302                 mutex_unlock(&disc->disc_mutex);
 303                 break;
 304         default:
 305                 FC_DBG("Received an unsupported request. opcode (%x)\n", op);
 306                 break;
 307         }
 308 }
 309
 310 /**
 311  * fc_disc_restart() - Restart discovery
 312  * @lport: FC discovery context
 313  *
 314  * Locking Note: This function expects that the disc mutex
 315  *               is already locked.
 316  */
 317 static void fc_disc_restart(struct fc_disc *disc)
 318 {
 319         struct fc_rport *rport;
 320         struct fc_rport_libfc_priv *rdata, *next;
 321         struct fc_lport *lport = disc->lport;
 322
 323         FC_DEBUG_DISC("Restarting discovery for port (%6x)\n",
 324                       fc_host_port_id(lport->host));
 325
 326         list_for_each_entry_safe(rdata, next, &disc->rports, peers) {
 327                 rport = PRIV_TO_RPORT(rdata);
 328                 FC_DEBUG_DISC("list_del(%6x)\n", rport->port_id);
 329                 list_del(&rdata->peers);
 330                 lport->tt.rport_logoff(rport);
 331         }
 332
 333         disc->requested = 1;
 334         if (!disc->pending)
 335                 fc_disc_gpn_ft_req(disc);
 336 }
 337
 338 /**
 339  * fc_disc_start() - Fibre Channel Target discovery
 340  * @lport: FC local port
 341  *
 342  * Returns non-zero if discovery cannot be started.
 343  */
 344 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
 345                                                 enum fc_disc_event),
 346                           struct fc_lport *lport)
 347 {
 348         struct fc_rport *rport;
 349         struct fc_rport_identifiers ids;
 350         struct fc_disc *disc = &lport->disc;
 351
 352         /*
 353          * At this point we may have a new disc job or an existing
 354          * one. Either way, let's lock when we make changes to it
 355          * and send the GPN_FT request.
 356          */
 357         mutex_lock(&disc->disc_mutex);
 358
 359         disc->disc_callback = disc_callback;
 360
 361         /*
 362          * If not ready, or already running discovery, just set request flag.
 363          */
 364         disc->requested = 1;
 365
 366         if (disc->pending) {
 367                 mutex_unlock(&disc->disc_mutex);
 368                 return;
 369         }
 370
 371         /*
 372          * Handle point-to-point mode as a simple discovery
 373          * of the remote port. Yucky, yucky, yuck, yuck!
 374          */
 375         rport = disc->lport->ptp_rp;
 376         if (rport) {
 377                 ids.port_id = rport->port_id;
 378                 ids.port_name = rport->port_name;
 379                 ids.node_name = rport->node_name;
 380                 ids.roles = FC_RPORT_ROLE_UNKNOWN;
 381                 get_device(&rport->dev);
 382
 383                 if (!fc_disc_new_target(disc, rport, &ids)) {
 384                         disc->event = DISC_EV_SUCCESS;
 385                         fc_disc_done(disc);
 386                 }
 387                 put_device(&rport->dev);
 388         } else {
 389                 fc_disc_gpn_ft_req(disc);       /* get ports by FC-4 type */
 390         }
 391
 392         mutex_unlock(&disc->disc_mutex);
 393 }
 394
 395 static struct fc_rport_operations fc_disc_rport_ops = {
 396         .event_callback = fc_disc_rport_callback,
 397 };
 398
 399 /**
 400  * fc_disc_new_target() - Handle new target found by discovery
 401  * @lport: FC local port
 402  * @rport: The previous FC remote port (NULL if new remote port)
 403  * @ids: Identifiers for the new FC remote port
 404  *
 405  * Locking Note: This function expects that the disc_mutex is locked
 406  *               before it is called.
 407  */
 408 static int fc_disc_new_target(struct fc_disc *disc,
 409                               struct fc_rport *rport,
 410                               struct fc_rport_identifiers *ids)
 411 {
 412         struct fc_lport *lport = disc->lport;
 413         struct fc_rport_libfc_priv *rdata;
 414         int error = 0;
 415
 416         if (rport && ids->port_name) {
 417                 if (rport->port_name == -1) {
 418                         /*
 419                          * Set WWN and fall through to notify of create.
 420                          */
 421                         fc_rport_set_name(rport, ids->port_name,
 422                                           rport->node_name);
 423                 } else if (rport->port_name != ids->port_name) {
 424                         /*
 425                          * This is a new port with the same FCID as
 426                          * a previously-discovered port.  Presumably the old
 427                          * port logged out and a new port logged in and was
 428                          * assigned the same FCID.  This should be rare.
 429                          * Delete the old one and fall thru to re-create.
 430                          */
 431                         fc_disc_del_target(disc, rport);
 432                         rport = NULL;
 433                 }
 434         }
 435         if (((ids->port_name != -1) || (ids->port_id != -1)) &&
 436             ids->port_id != fc_host_port_id(lport->host) &&
 437             ids->port_name != lport->wwpn) {
 438                 if (!rport) {
 439                         rport = lport->tt.rport_lookup(lport, ids->port_id);
 440                         if (!rport) {
 441                                 struct fc_disc_port dp;
 442                                 dp.lp = lport;
 443                                 dp.ids.port_id = ids->port_id;
 444                                 dp.ids.port_name = ids->port_name;
 445                                 dp.ids.node_name = ids->node_name;
 446                                 dp.ids.roles = ids->roles;
 447                                 rport = lport->tt.rport_create(&dp);
 448                         }
 449                         if (!rport)
 450                                 error = -ENOMEM;
 451                 }
 452                 if (rport) {
 453                         rdata = rport->dd_data;
 454                         rdata->ops = &fc_disc_rport_ops;
 455                         rdata->rp_state = RPORT_ST_INIT;
 456                         list_add_tail(&rdata->peers, &disc->rogue_rports);
 457                         lport->tt.rport_login(rport);
 458                 }
 459         }
 460         return error;
 461 }
 462
 463 /**
 464  * fc_disc_del_target() - Delete a target
 465  * @disc: FC discovery context
 466  * @rport: The remote port to be removed
 467  */
 468 static void fc_disc_del_target(struct fc_disc *disc, struct fc_rport *rport)
 469 {
 470         struct fc_lport *lport = disc->lport;
 471         struct fc_rport_libfc_priv *rdata = rport->dd_data;
 472         list_del(&rdata->peers);
 473         lport->tt.rport_logoff(rport);
 474 }
 475
 476 /**
 477  * fc_disc_done() - Discovery has been completed
 478  * @disc: FC discovery context
 479  * Locking Note: This function expects that the disc mutex is locked before
 480  * it is called. The discovery callback is then made with the lock released,
 481  * and the lock is re-taken before returning from this function
 482  */
 483 static void fc_disc_done(struct fc_disc *disc)
 484 {
 485         struct fc_lport *lport = disc->lport;
 486         enum fc_disc_event event;
 487
 488         FC_DEBUG_DISC("Discovery complete for port (%6x)\n",
 489                       fc_host_port_id(lport->host));
 490
 491         event = disc->event;
 492         disc->event = DISC_EV_NONE;
 493
 494         if (disc->requested)
 495                 fc_disc_gpn_ft_req(disc);
 496         else
 497                 disc->pending = 0;
 498
 499         mutex_unlock(&disc->disc_mutex);
 500         disc->disc_callback(lport, event);
 501         mutex_lock(&disc->disc_mutex);
 502 }
 503
 504 /**
 505  * fc_disc_error() - Handle error on dNS request
 506  * @disc: FC discovery context
 507  * @fp: The frame pointer
 508  */
 509 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
 510 {
 511         struct fc_lport *lport = disc->lport;
 512         unsigned long delay = 0;
 513         if (fc_disc_debug)
 514                 FC_DBG("Error %ld, retries %d/%d\n",
 515                        PTR_ERR(fp), disc->retry_count,
 516                        FC_DISC_RETRY_LIMIT);
 517
 518         if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
 519                 /*
 520                  * Memory allocation failure, or the exchange timed out,
 521                  * retry after delay.
 522                  */
 523                 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
 524                         /* go ahead and retry */
 525                         if (!fp)
 526                                 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
 527                         else {
 528                                 delay = msecs_to_jiffies(lport->e_d_tov);
 529
 530                                 /* timeout faster first time */
 531                                 if (!disc->retry_count)
 532                                         delay /= 4;
 533                         }
 534                         disc->retry_count++;
 535                         schedule_delayed_work(&disc->disc_work, delay);
 536                 } else {
 537                         /* exceeded retries */
 538                         disc->event = DISC_EV_FAILED;
 539                         fc_disc_done(disc);
 540                 }
 541         }
 542 }
 543
 544 /**
 545  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
 546  * @lport: FC discovery context
 547  *
 548  * Locking Note: This function expects that the disc_mutex is locked
 549  *               before it is called.
 550  */
 551 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
 552 {
 553         struct fc_frame *fp;
 554         struct fc_lport *lport = disc->lport;
 555
 556         WARN_ON(!fc_lport_test_ready(lport));
 557
 558         disc->pending = 1;
 559         disc->requested = 0;
 560
 561         disc->buf_len = 0;
 562         disc->seq_count = 0;
 563         fp = fc_frame_alloc(lport,
 564                             sizeof(struct fc_ct_hdr) +
 565                             sizeof(struct fc_ns_gid_ft));
 566         if (!fp)
 567                 goto err;
 568
 569         if (lport->tt.elsct_send(lport, NULL, fp,
 570                                  FC_NS_GPN_FT,
 571                                  fc_disc_gpn_ft_resp,
 572                                  disc, lport->e_d_tov))
 573                 return;
 574 err:
 575         fc_disc_error(disc, fp);
 576 }
 577
 578 /**
 579  * fc_disc_gpn_ft_parse() - Parse the list of IDs and names resulting from a request
 580  * @lport: Fibre Channel host port instance
 581  * @buf: GPN_FT response buffer
 582  * @len: size of response buffer
 583  */
 584 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
 585 {
 586         struct fc_lport *lport;
 587         struct fc_gpn_ft_resp *np;
 588         char *bp;
 589         size_t plen;
 590         size_t tlen;
 591         int error = 0;
 592         struct fc_disc_port dp;
 593         struct fc_rport *rport;
 594         struct fc_rport_libfc_priv *rdata;
 595
 596         lport = disc->lport;
 597
 598         /*
 599          * Handle partial name record left over from previous call.
 600          */
 601         bp = buf;
 602         plen = len;
 603         np = (struct fc_gpn_ft_resp *)bp;
 604         tlen = disc->buf_len;
 605         if (tlen) {
 606                 WARN_ON(tlen >= sizeof(*np));
 607                 plen = sizeof(*np) - tlen;
 608                 WARN_ON(plen <= 0);
 609                 WARN_ON(plen >= sizeof(*np));
 610                 if (plen > len)
 611                         plen = len;
 612                 np = &disc->partial_buf;
 613                 memcpy((char *)np + tlen, bp, plen);
 614
 615                 /*
 616                  * Set bp so that the loop below will advance it to the
 617                  * first valid full name element.
 618                  */
 619                 bp -= tlen;
 620                 len += tlen;
 621                 plen += tlen;
 622                 disc->buf_len = (unsigned char) plen;
 623                 if (plen == sizeof(*np))
 624                         disc->buf_len = 0;
 625         }
 626
 627         /*
 628          * Handle full name records, including the one filled from above.
 629          * Normally, np == bp and plen == len, but from the partial case above,
 630          * bp, len describe the overall buffer, and np, plen describe the
 631          * partial buffer, which if would usually be full now.
 632          * After the first time through the loop, things return to "normal".
 633          */
 634         while (plen >= sizeof(*np)) {
 635                 dp.lp = lport;
 636                 dp.ids.port_id = ntoh24(np->fp_fid);
 637                 dp.ids.port_name = ntohll(np->fp_wwpn);
 638                 dp.ids.node_name = -1;
 639                 dp.ids.roles = FC_RPORT_ROLE_UNKNOWN;
 640
 641                 if ((dp.ids.port_id != fc_host_port_id(lport->host)) &&
 642                     (dp.ids.port_name != lport->wwpn)) {
 643                         rport = lport->tt.rport_create(&dp);
 644                         if (rport) {
 645                                 rdata = rport->dd_data;
 646                                 rdata->ops = &fc_disc_rport_ops;
 647                                 rdata->local_port = lport;
 648                                 list_add_tail(&rdata->peers,
 649                                               &disc->rogue_rports);
 650                                 lport->tt.rport_login(rport);
 651                         } else
 652                                 FC_DBG("Failed to allocate memory for "
 653                                        "the newly discovered port (%6x)\n",
 654                                        dp.ids.port_id);
 655                 }
 656
 657                 if (np->fp_flags & FC_NS_FID_LAST) {
 658                         disc->event = DISC_EV_SUCCESS;
 659                         fc_disc_done(disc);
 660                         len = 0;
 661                         break;
 662                 }
 663                 len -= sizeof(*np);
 664                 bp += sizeof(*np);
 665                 np = (struct fc_gpn_ft_resp *)bp;
 666                 plen = len;
 667         }
 668
 669         /*
 670          * Save any partial record at the end of the buffer for next time.
 671          */
 672         if (error == 0 && len > 0 && len < sizeof(*np)) {
 673                 if (np != &disc->partial_buf) {
 674                         FC_DEBUG_DISC("Partial buffer remains "
 675                                       "for discovery by (%6x)\n",
 676                                       fc_host_port_id(lport->host));
 677                         memcpy(&disc->partial_buf, np, len);
 678                 }
 679                 disc->buf_len = (unsigned char) len;
 680         } else {
 681                 disc->buf_len = 0;
 682         }
 683         return error;
 684 }
 685
 686 /**
 687  * fc_disc_timeout() - Retry handler for the disc component
 688  * @work: Structure holding disc obj that needs retry discovery
 689  *
 690  * Handle retry of memory allocation for remote ports.
 691  */
 692 static void fc_disc_timeout(struct work_struct *work)
 693 {
 694         struct fc_disc *disc = container_of(work,
 695                                             struct fc_disc,
 696                                             disc_work.work);
 697         mutex_lock(&disc->disc_mutex);
 698         if (disc->requested && !disc->pending)
 699                 fc_disc_gpn_ft_req(disc);
 700         mutex_unlock(&disc->disc_mutex);
 701 }
 702
 703 /**
 704  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
 705  * @sp: Current sequence of GPN_FT exchange
 706  * @fp: response frame
 707  * @lp_arg: Fibre Channel host port instance
 708  *
 709  * Locking Note: This function is called without disc mutex held, and
 710  *               should do all its processing with the mutex held
 711  */
 712 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
 713                                 void *disc_arg)
 714 {
 715         struct fc_disc *disc = disc_arg;
 716         struct fc_ct_hdr *cp;
 717         struct fc_frame_header *fh;
 718         unsigned int seq_cnt;
 719         void *buf = NULL;
 720         unsigned int len;
 721         int error;
 722
 723         mutex_lock(&disc->disc_mutex);
 724         FC_DEBUG_DISC("Received a GPN_FT response on port (%6x)\n",
 725                       fc_host_port_id(disc->lport->host));
 726
 727         if (IS_ERR(fp)) {
 728                 fc_disc_error(disc, fp);
 729                 mutex_unlock(&disc->disc_mutex);
 730                 return;
 731         }
 732
 733         WARN_ON(!fc_frame_is_linear(fp));       /* buffer must be contiguous */
 734         fh = fc_frame_header_get(fp);
 735         len = fr_len(fp) - sizeof(*fh);
 736         seq_cnt = ntohs(fh->fh_seq_cnt);
 737         if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 &&
 738             disc->seq_count == 0) {
 739                 cp = fc_frame_payload_get(fp, sizeof(*cp));
 740                 if (!cp) {
 741                         FC_DBG("GPN_FT response too short, len %d\n",
 742                                fr_len(fp));
 743                 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 744
 745                         /* Accepted, parse the response. */
 746                         buf = cp + 1;
 747                         len -= sizeof(*cp);
 748                 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 749                         FC_DBG("GPN_FT rejected reason %x exp %x "
 750                                "(check zoning)\n", cp->ct_reason,
 751                                cp->ct_explan);
 752                         disc->event = DISC_EV_FAILED;
 753                         fc_disc_done(disc);
 754                 } else {
 755                         FC_DBG("GPN_FT unexpected response code %x\n",
 756                                ntohs(cp->ct_cmd));
 757                 }
 758         } else if (fr_sof(fp) == FC_SOF_N3 &&
 759                    seq_cnt == disc->seq_count) {
 760                 buf = fh + 1;
 761         } else {
 762                 FC_DBG("GPN_FT unexpected frame - out of sequence? "
 763                        "seq_cnt %x expected %x sof %x eof %x\n",
 764                        seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
 765         }
 766         if (buf) {
 767                 error = fc_disc_gpn_ft_parse(disc, buf, len);
 768                 if (error)
 769                         fc_disc_error(disc, fp);
 770                 else
 771                         disc->seq_count++;
 772         }
 773         fc_frame_free(fp);
 774
 775         mutex_unlock(&disc->disc_mutex);
 776 }
 777
 778 /**
 779  * fc_disc_single() - Discover the directory information for a single target
 780  * @lport: FC local port
 781  * @dp: The port to rediscover
 782  *
 783  * Locking Note: This function expects that the disc_mutex is locked
 784  *               before it is called.
 785  */
 786 static void fc_disc_single(struct fc_disc *disc, struct fc_disc_port *dp)
 787 {
 788         struct fc_lport *lport;
 789         struct fc_rport *new_rport;
 790         struct fc_rport_libfc_priv *rdata;
 791
 792         lport = disc->lport;
 793
 794         if (dp->ids.port_id == fc_host_port_id(lport->host))
 795                 goto out;
 796
 797         new_rport = lport->tt.rport_create(dp);
 798         if (new_rport) {
 799                 rdata = new_rport->dd_data;
 800                 rdata->ops = &fc_disc_rport_ops;
 801                 kfree(dp);
 802                 list_add_tail(&rdata->peers, &disc->rogue_rports);
 803                 lport->tt.rport_login(new_rport);
 804         }
 805         return;
 806 out:
 807         kfree(dp);
 808 }
 809
 810 /**
 811  * fc_disc_stop() - Stop discovery for a given lport
 812  * @lport: The lport that discovery should stop for
 813  */
 814 void fc_disc_stop(struct fc_lport *lport)
 815 {
 816         struct fc_disc *disc = &lport->disc;
 817
 818         if (disc) {
 819                 cancel_delayed_work_sync(&disc->disc_work);
 820                 fc_disc_stop_rports(disc);
 821         }
 822 }
 823
 824 /**
 825  * fc_disc_stop_final() - Stop discovery for a given lport
 826  * @lport: The lport that discovery should stop for
 827  *
 828  * This function will block until discovery has been
 829  * completely stopped and all rports have been deleted.
 830  */
 831 void fc_disc_stop_final(struct fc_lport *lport)
 832 {
 833         fc_disc_stop(lport);
 834         lport->tt.rport_flush_queue();
 835 }
 836
 837 /**
 838  * fc_disc_init() - Initialize the discovery block
 839  * @lport: FC local port
 840  */
 841 int fc_disc_init(struct fc_lport *lport)
 842 {
 843         struct fc_disc *disc;
 844
 845         if (!lport->tt.disc_start)
 846                 lport->tt.disc_start = fc_disc_start;
 847
 848         if (!lport->tt.disc_stop)
 849                 lport->tt.disc_stop = fc_disc_stop;
 850
 851         if (!lport->tt.disc_stop_final)
 852                 lport->tt.disc_stop_final = fc_disc_stop_final;
 853
 854         if (!lport->tt.disc_recv_req)
 855                 lport->tt.disc_recv_req = fc_disc_recv_req;
 856
 857         if (!lport->tt.rport_lookup)
 858                 lport->tt.rport_lookup = fc_disc_lookup_rport;
 859
 860         disc = &lport->disc;
 861         INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
 862         mutex_init(&disc->disc_mutex);
 863         INIT_LIST_HEAD(&disc->rports);
 864         INIT_LIST_HEAD(&disc->rogue_rports);
 865
 866         disc->lport = lport;
 867         disc->delay = FC_DISC_DELAY;
 868         disc->event = DISC_EV_NONE;
 869
 870         return 0;
 871 }
 872 EXPORT_SYMBOL(fc_disc_init);