release/src-rt-6.x.4708/linux/linux-2.6.36/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;
  67
  68         lport = fc_disc_lport(disc);
  69
  70         mutex_lock(&disc->disc_mutex);
  71         list_for_each_entry_rcu(rdata, &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  * @disc:  The discovery object to which the RSCN applies
  79  * @fp:    The RSCN frame
  80  *
  81  * Locking Note: This function expects that the disc_mutex is locked
  82  *               before it is called.
  83  */
  84 static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
  85 {
  86         struct fc_lport *lport;
  87         struct fc_els_rscn *rp;
  88         struct fc_els_rscn_page *pp;
  89         struct fc_seq_els_data rjt_data;
  90         unsigned int len;
  91         int redisc = 0;
  92         enum fc_els_rscn_ev_qual ev_qual;
  93         enum fc_els_rscn_addr_fmt fmt;
  94         LIST_HEAD(disc_ports);
  95         struct fc_disc_port *dp, *next;
  96
  97         lport = fc_disc_lport(disc);
  98
  99         FC_DISC_DBG(disc, "Received an RSCN event\n");
 100
 101         /* make sure the frame contains an RSCN message */
 102         rp = fc_frame_payload_get(fp, sizeof(*rp));
 103         if (!rp)
 104                 goto reject;
 105         /* make sure the page length is as expected (4 bytes) */
 106         if (rp->rscn_page_len != sizeof(*pp))
 107                 goto reject;
 108         /* get the RSCN payload length */
 109         len = ntohs(rp->rscn_plen);
 110         if (len < sizeof(*rp))
 111                 goto reject;
 112         /* make sure the frame contains the expected payload */
 113         rp = fc_frame_payload_get(fp, len);
 114         if (!rp)
 115                 goto reject;
 116         /* payload must be a multiple of the RSCN page size */
 117         len -= sizeof(*rp);
 118         if (len % sizeof(*pp))
 119                 goto reject;
 120
 121         for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
 122                 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
 123                 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
 124                 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
 125                 fmt &= ELS_RSCN_ADDR_FMT_MASK;
 126                 /*
 127                  * if we get an address format other than port
 128                  * (area, domain, fabric), then do a full discovery
 129                  */
 130                 switch (fmt) {
 131                 case ELS_ADDR_FMT_PORT:
 132                         FC_DISC_DBG(disc, "Port address format for port "
 133                                     "(%6.6x)\n", ntoh24(pp->rscn_fid));
 134                         dp = kzalloc(sizeof(*dp), GFP_KERNEL);
 135                         if (!dp) {
 136                                 redisc = 1;
 137                                 break;
 138                         }
 139                         dp->lp = lport;
 140                         dp->port_id = ntoh24(pp->rscn_fid);
 141                         list_add_tail(&dp->peers, &disc_ports);
 142                         break;
 143                 case ELS_ADDR_FMT_AREA:
 144                 case ELS_ADDR_FMT_DOM:
 145                 case ELS_ADDR_FMT_FAB:
 146                 default:
 147                         FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
 148                         redisc = 1;
 149                         break;
 150                 }
 151         }
 152         lport->tt.seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
 153
 154         /*
 155          * If not doing a complete rediscovery, do GPN_ID on
 156          * the individual ports mentioned in the list.
 157          * If any of these get an error, do a full rediscovery.
 158          * In any case, go through the list and free the entries.
 159          */
 160         list_for_each_entry_safe(dp, next, &disc_ports, peers) {
 161                 list_del(&dp->peers);
 162                 if (!redisc)
 163                         redisc = fc_disc_single(lport, dp);
 164                 kfree(dp);
 165         }
 166         if (redisc) {
 167                 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
 168                 fc_disc_restart(disc);
 169         } else {
 170                 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
 171                             "redisc %d state %d in_prog %d\n",
 172                             redisc, lport->state, disc->pending);
 173         }
 174         fc_frame_free(fp);
 175         return;
 176 reject:
 177         FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
 178         rjt_data.reason = ELS_RJT_LOGIC;
 179         rjt_data.explan = ELS_EXPL_NONE;
 180         lport->tt.seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
 181         fc_frame_free(fp);
 182 }
 183
 184 /**
 185  * fc_disc_recv_req() - Handle incoming requests
 186  * @lport: The local port receiving the request
 187  * @fp:    The request frame
 188  *
 189  * Locking Note: This function is called from the EM and will lock
 190  *               the disc_mutex before calling the handler for the
 191  *               request.
 192  */
 193 static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
 194 {
 195         u8 op;
 196         struct fc_disc *disc = &lport->disc;
 197
 198         op = fc_frame_payload_op(fp);
 199         switch (op) {
 200         case ELS_RSCN:
 201                 mutex_lock(&disc->disc_mutex);
 202                 fc_disc_recv_rscn_req(disc, fp);
 203                 mutex_unlock(&disc->disc_mutex);
 204                 break;
 205         default:
 206                 FC_DISC_DBG(disc, "Received an unsupported request, "
 207                             "the opcode is (%x)\n", op);
 208                 break;
 209         }
 210 }
 211
 212 /**
 213  * fc_disc_restart() - Restart discovery
 214  * @disc: The discovery object to be restarted
 215  *
 216  * Locking Note: This function expects that the disc mutex
 217  *               is already locked.
 218  */
 219 static void fc_disc_restart(struct fc_disc *disc)
 220 {
 221         if (!disc->disc_callback)
 222                 return;
 223
 224         FC_DISC_DBG(disc, "Restarting discovery\n");
 225
 226         disc->requested = 1;
 227         if (disc->pending)
 228                 return;
 229
 230         /*
 231          * Advance disc_id.  This is an arbitrary non-zero number that will
 232          * match the value in the fc_rport_priv after discovery for all
 233          * freshly-discovered remote ports.  Avoid wrapping to zero.
 234          */
 235         disc->disc_id = (disc->disc_id + 2) | 1;
 236         disc->retry_count = 0;
 237         fc_disc_gpn_ft_req(disc);
 238 }
 239
 240 /**
 241  * fc_disc_start() - Start discovery on a local port
 242  * @lport:         The local port to have discovery started on
 243  * @disc_callback: Callback function to be called when discovery is complete
 244  */
 245 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
 246                                                 enum fc_disc_event),
 247                           struct fc_lport *lport)
 248 {
 249         struct fc_disc *disc = &lport->disc;
 250
 251         /*
 252          * At this point we may have a new disc job or an existing
 253          * one. Either way, let's lock when we make changes to it
 254          * and send the GPN_FT request.
 255          */
 256         mutex_lock(&disc->disc_mutex);
 257         disc->disc_callback = disc_callback;
 258         fc_disc_restart(disc);
 259         mutex_unlock(&disc->disc_mutex);
 260 }
 261
 262 /**
 263  * fc_disc_done() - Discovery has been completed
 264  * @disc:  The discovery context
 265  * @event: The discovery completion status
 266  *
 267  * Locking Note: This function expects that the disc mutex is locked before
 268  * it is called. The discovery callback is then made with the lock released,
 269  * and the lock is re-taken before returning from this function
 270  */
 271 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
 272 {
 273         struct fc_lport *lport = fc_disc_lport(disc);
 274         struct fc_rport_priv *rdata;
 275
 276         FC_DISC_DBG(disc, "Discovery complete\n");
 277
 278         disc->pending = 0;
 279         if (disc->requested) {
 280                 fc_disc_restart(disc);
 281                 return;
 282         }
 283
 284         /*
 285          * Go through all remote ports.  If they were found in the latest
 286          * discovery, reverify or log them in.  Otherwise, log them out.
 287          * Skip ports which were never discovered.  These are the dNS port
 288          * and ports which were created by PLOGI.
 289          */
 290         list_for_each_entry_rcu(rdata, &disc->rports, peers) {
 291                 if (!rdata->disc_id)
 292                         continue;
 293                 if (rdata->disc_id == disc->disc_id)
 294                         lport->tt.rport_login(rdata);
 295                 else
 296                         lport->tt.rport_logoff(rdata);
 297         }
 298
 299         mutex_unlock(&disc->disc_mutex);
 300         disc->disc_callback(lport, event);
 301         mutex_lock(&disc->disc_mutex);
 302 }
 303
 304 /**
 305  * fc_disc_error() - Handle error on dNS request
 306  * @disc: The discovery context
 307  * @fp:   The error code encoded as a frame pointer
 308  */
 309 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
 310 {
 311         struct fc_lport *lport = fc_disc_lport(disc);
 312         unsigned long delay = 0;
 313
 314         FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
 315                     PTR_ERR(fp), disc->retry_count,
 316                     FC_DISC_RETRY_LIMIT);
 317
 318         if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
 319                 /*
 320                  * Memory allocation failure, or the exchange timed out,
 321                  * retry after delay.
 322                  */
 323                 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
 324                         /* go ahead and retry */
 325                         if (!fp)
 326                                 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
 327                         else {
 328                                 delay = msecs_to_jiffies(lport->e_d_tov);
 329
 330                                 /* timeout faster first time */
 331                                 if (!disc->retry_count)
 332                                         delay /= 4;
 333                         }
 334                         disc->retry_count++;
 335                         schedule_delayed_work(&disc->disc_work, delay);
 336                 } else
 337                         fc_disc_done(disc, DISC_EV_FAILED);
 338         }
 339 }
 340
 341 /**
 342  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
 343  * @lport: The discovery context
 344  *
 345  * Locking Note: This function expects that the disc_mutex is locked
 346  *               before it is called.
 347  */
 348 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
 349 {
 350         struct fc_frame *fp;
 351         struct fc_lport *lport = fc_disc_lport(disc);
 352
 353         WARN_ON(!fc_lport_test_ready(lport));
 354
 355         disc->pending = 1;
 356         disc->requested = 0;
 357
 358         disc->buf_len = 0;
 359         disc->seq_count = 0;
 360         fp = fc_frame_alloc(lport,
 361                             sizeof(struct fc_ct_hdr) +
 362                             sizeof(struct fc_ns_gid_ft));
 363         if (!fp)
 364                 goto err;
 365
 366         if (lport->tt.elsct_send(lport, 0, fp,
 367                                  FC_NS_GPN_FT,
 368                                  fc_disc_gpn_ft_resp,
 369                                  disc, 3 * lport->r_a_tov))
 370                 return;
 371 err:
 372         fc_disc_error(disc, NULL);
 373 }
 374
 375 /**
 376  * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
 377  * @lport: The local port the GPN_FT was received on
 378  * @buf:   The GPN_FT response buffer
 379  * @len:   The size of response buffer
 380  *
 381  * Goes through the list of IDs and names resulting from a request.
 382  */
 383 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
 384 {
 385         struct fc_lport *lport;
 386         struct fc_gpn_ft_resp *np;
 387         char *bp;
 388         size_t plen;
 389         size_t tlen;
 390         int error = 0;
 391         struct fc_rport_identifiers ids;
 392         struct fc_rport_priv *rdata;
 393
 394         lport = fc_disc_lport(disc);
 395         disc->seq_count++;
 396
 397         /*
 398          * Handle partial name record left over from previous call.
 399          */
 400         bp = buf;
 401         plen = len;
 402         np = (struct fc_gpn_ft_resp *)bp;
 403         tlen = disc->buf_len;
 404         disc->buf_len = 0;
 405         if (tlen) {
 406                 WARN_ON(tlen >= sizeof(*np));
 407                 plen = sizeof(*np) - tlen;
 408                 WARN_ON(plen <= 0);
 409                 WARN_ON(plen >= sizeof(*np));
 410                 if (plen > len)
 411                         plen = len;
 412                 np = &disc->partial_buf;
 413                 memcpy((char *)np + tlen, bp, plen);
 414
 415                 /*
 416                  * Set bp so that the loop below will advance it to the
 417                  * first valid full name element.
 418                  */
 419                 bp -= tlen;
 420                 len += tlen;
 421                 plen += tlen;
 422                 disc->buf_len = (unsigned char) plen;
 423                 if (plen == sizeof(*np))
 424                         disc->buf_len = 0;
 425         }
 426
 427         /*
 428          * Handle full name records, including the one filled from above.
 429          * Normally, np == bp and plen == len, but from the partial case above,
 430          * bp, len describe the overall buffer, and np, plen describe the
 431          * partial buffer, which if would usually be full now.
 432          * After the first time through the loop, things return to "normal".
 433          */
 434         while (plen >= sizeof(*np)) {
 435                 ids.port_id = ntoh24(np->fp_fid);
 436                 ids.port_name = ntohll(np->fp_wwpn);
 437
 438                 if (ids.port_id != lport->port_id &&
 439                     ids.port_name != lport->wwpn) {
 440                         rdata = lport->tt.rport_create(lport, ids.port_id);
 441                         if (rdata) {
 442                                 rdata->ids.port_name = ids.port_name;
 443                                 rdata->disc_id = disc->disc_id;
 444                         } else {
 445                                 printk(KERN_WARNING "libfc: Failed to allocate "
 446                                        "memory for the newly discovered port "
 447                                        "(%6.6x)\n", ids.port_id);
 448                                 error = -ENOMEM;
 449                         }
 450                 }
 451
 452                 if (np->fp_flags & FC_NS_FID_LAST) {
 453                         fc_disc_done(disc, DISC_EV_SUCCESS);
 454                         len = 0;
 455                         break;
 456                 }
 457                 len -= sizeof(*np);
 458                 bp += sizeof(*np);
 459                 np = (struct fc_gpn_ft_resp *)bp;
 460                 plen = len;
 461         }
 462
 463         /*
 464          * Save any partial record at the end of the buffer for next time.
 465          */
 466         if (error == 0 && len > 0 && len < sizeof(*np)) {
 467                 if (np != &disc->partial_buf) {
 468                         FC_DISC_DBG(disc, "Partial buffer remains "
 469                                     "for discovery\n");
 470                         memcpy(&disc->partial_buf, np, len);
 471                 }
 472                 disc->buf_len = (unsigned char) len;
 473         }
 474         return error;
 475 }
 476
 477 /**
 478  * fc_disc_timeout() - Handler for discovery timeouts
 479  * @work: Structure holding discovery context that needs to retry discovery
 480  */
 481 static void fc_disc_timeout(struct work_struct *work)
 482 {
 483         struct fc_disc *disc = container_of(work,
 484                                             struct fc_disc,
 485                                             disc_work.work);
 486         mutex_lock(&disc->disc_mutex);
 487         fc_disc_gpn_ft_req(disc);
 488         mutex_unlock(&disc->disc_mutex);
 489 }
 490
 491 /**
 492  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
 493  * @sp:     The sequence that the GPN_FT response was received on
 494  * @fp:     The GPN_FT response frame
 495  * @lp_arg: The discovery context
 496  *
 497  * Locking Note: This function is called without disc mutex held, and
 498  *               should do all its processing with the mutex held
 499  */
 500 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
 501                                 void *disc_arg)
 502 {
 503         struct fc_disc *disc = disc_arg;
 504         struct fc_ct_hdr *cp;
 505         struct fc_frame_header *fh;
 506         enum fc_disc_event event = DISC_EV_NONE;
 507         unsigned int seq_cnt;
 508         unsigned int len;
 509         int error = 0;
 510
 511         mutex_lock(&disc->disc_mutex);
 512         FC_DISC_DBG(disc, "Received a GPN_FT response\n");
 513
 514         if (IS_ERR(fp)) {
 515                 fc_disc_error(disc, fp);
 516                 mutex_unlock(&disc->disc_mutex);
 517                 return;
 518         }
 519
 520         WARN_ON(!fc_frame_is_linear(fp));       /* buffer must be contiguous */
 521         fh = fc_frame_header_get(fp);
 522         len = fr_len(fp) - sizeof(*fh);
 523         seq_cnt = ntohs(fh->fh_seq_cnt);
 524         if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
 525                 cp = fc_frame_payload_get(fp, sizeof(*cp));
 526                 if (!cp) {
 527                         FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
 528                                     fr_len(fp));
 529                         event = DISC_EV_FAILED;
 530                 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 531
 532                         /* Accepted, parse the response. */
 533                         len -= sizeof(*cp);
 534                         error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
 535                 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 536                         FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
 537                                     "(check zoning)\n", cp->ct_reason,
 538                                     cp->ct_explan);
 539                         event = DISC_EV_FAILED;
 540                         if (cp->ct_reason == FC_FS_RJT_UNABL &&
 541                             cp->ct_explan == FC_FS_EXP_FTNR)
 542                                 event = DISC_EV_SUCCESS;
 543                 } else {
 544                         FC_DISC_DBG(disc, "GPN_FT unexpected response code "
 545                                     "%x\n", ntohs(cp->ct_cmd));
 546                         event = DISC_EV_FAILED;
 547                 }
 548         } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
 549                 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
 550         } else {
 551                 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
 552                             "seq_cnt %x expected %x sof %x eof %x\n",
 553                             seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
 554                 event = DISC_EV_FAILED;
 555         }
 556         if (error)
 557                 fc_disc_error(disc, fp);
 558         else if (event != DISC_EV_NONE)
 559                 fc_disc_done(disc, event);
 560         fc_frame_free(fp);
 561         mutex_unlock(&disc->disc_mutex);
 562 }
 563
 564 /**
 565  * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
 566  * @sp:        The sequence the GPN_ID is on
 567  * @fp:        The response frame
 568  * @rdata_arg: The remote port that sent the GPN_ID response
 569  *
 570  * Locking Note: This function is called without disc mutex held.
 571  */
 572 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
 573                                 void *rdata_arg)
 574 {
 575         struct fc_rport_priv *rdata = rdata_arg;
 576         struct fc_rport_priv *new_rdata;
 577         struct fc_lport *lport;
 578         struct fc_disc *disc;
 579         struct fc_ct_hdr *cp;
 580         struct fc_ns_gid_pn *pn;
 581         u64 port_name;
 582
 583         lport = rdata->local_port;
 584         disc = &lport->disc;
 585
 586         mutex_lock(&disc->disc_mutex);
 587         if (PTR_ERR(fp) == -FC_EX_CLOSED)
 588                 goto out;
 589         if (IS_ERR(fp))
 590                 goto redisc;
 591
 592         cp = fc_frame_payload_get(fp, sizeof(*cp));
 593         if (!cp)
 594                 goto redisc;
 595         if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 596                 if (fr_len(fp) < sizeof(struct fc_frame_header) +
 597                     sizeof(*cp) + sizeof(*pn))
 598                         goto redisc;
 599                 pn = (struct fc_ns_gid_pn *)(cp + 1);
 600                 port_name = get_unaligned_be64(&pn->fn_wwpn);
 601                 if (rdata->ids.port_name == -1)
 602                         rdata->ids.port_name = port_name;
 603                 else if (rdata->ids.port_name != port_name) {
 604                         FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
 605                                     "Port-id %6.6x wwpn %16.16llx\n",
 606                                     rdata->ids.port_id, port_name);
 607                         lport->tt.rport_logoff(rdata);
 608
 609                         new_rdata = lport->tt.rport_create(lport,
 610                                                            rdata->ids.port_id);
 611                         if (new_rdata) {
 612                                 new_rdata->disc_id = disc->disc_id;
 613                                 lport->tt.rport_login(new_rdata);
 614                         }
 615                         goto out;
 616                 }
 617                 rdata->disc_id = disc->disc_id;
 618                 lport->tt.rport_login(rdata);
 619         } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 620                 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
 621                             cp->ct_reason, cp->ct_explan);
 622                 lport->tt.rport_logoff(rdata);
 623         } else {
 624                 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
 625                             ntohs(cp->ct_cmd));
 626 redisc:
 627                 fc_disc_restart(disc);
 628         }
 629 out:
 630         mutex_unlock(&disc->disc_mutex);
 631         kref_put(&rdata->kref, lport->tt.rport_destroy);
 632 }
 633
 634 /**
 635  * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
 636  * @lport: The local port to initiate discovery on
 637  * @rdata: remote port private data
 638  *
 639  * Locking Note: This function expects that the disc_mutex is locked
 640  *               before it is called.
 641  * On failure, an error code is returned.
 642  */
 643 static int fc_disc_gpn_id_req(struct fc_lport *lport,
 644                               struct fc_rport_priv *rdata)
 645 {
 646         struct fc_frame *fp;
 647
 648         fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
 649                             sizeof(struct fc_ns_fid));
 650         if (!fp)
 651                 return -ENOMEM;
 652         if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
 653                                   fc_disc_gpn_id_resp, rdata,
 654                                   3 * lport->r_a_tov))
 655                 return -ENOMEM;
 656         kref_get(&rdata->kref);
 657         return 0;
 658 }
 659
 660 /**
 661  * fc_disc_single() - Discover the directory information for a single target
 662  * @lport: The local port the remote port is associated with
 663  * @dp:    The port to rediscover
 664  *
 665  * Locking Note: This function expects that the disc_mutex is locked
 666  *               before it is called.
 667  */
 668 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
 669 {
 670         struct fc_rport_priv *rdata;
 671
 672         rdata = lport->tt.rport_create(lport, dp->port_id);
 673         if (!rdata)
 674                 return -ENOMEM;
 675         rdata->disc_id = 0;
 676         return fc_disc_gpn_id_req(lport, rdata);
 677 }
 678
 679 /**
 680  * fc_disc_stop() - Stop discovery for a given lport
 681  * @lport: The local port that discovery should stop on
 682  */
 683 void fc_disc_stop(struct fc_lport *lport)
 684 {
 685         struct fc_disc *disc = &lport->disc;
 686
 687         if (disc) {
 688                 cancel_delayed_work_sync(&disc->disc_work);
 689                 fc_disc_stop_rports(disc);
 690         }
 691 }
 692
 693 /**
 694  * fc_disc_stop_final() - Stop discovery for a given lport
 695  * @lport: The lport that discovery should stop on
 696  *
 697  * This function will block until discovery has been
 698  * completely stopped and all rports have been deleted.
 699  */
 700 void fc_disc_stop_final(struct fc_lport *lport)
 701 {
 702         fc_disc_stop(lport);
 703         lport->tt.rport_flush_queue();
 704 }
 705
 706 /**
 707  * fc_disc_init() - Initialize the discovery layer for a local port
 708  * @lport: The local port that needs the discovery layer to be initialized
 709  */
 710 int fc_disc_init(struct fc_lport *lport)
 711 {
 712         struct fc_disc *disc;
 713
 714         if (!lport->tt.disc_start)
 715                 lport->tt.disc_start = fc_disc_start;
 716
 717         if (!lport->tt.disc_stop)
 718                 lport->tt.disc_stop = fc_disc_stop;
 719
 720         if (!lport->tt.disc_stop_final)
 721                 lport->tt.disc_stop_final = fc_disc_stop_final;
 722
 723         if (!lport->tt.disc_recv_req)
 724                 lport->tt.disc_recv_req = fc_disc_recv_req;
 725
 726         disc = &lport->disc;
 727         INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
 728         mutex_init(&disc->disc_mutex);
 729         INIT_LIST_HEAD(&disc->rports);
 730
 731         disc->priv = lport;
 732
 733         return 0;
 734 }
 735 EXPORT_SYMBOL(fc_disc_init);