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