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                 fc_frame_free(fp);
 209                 break;
 210         }
 211 }
 212
 213 /**
 214  * fc_disc_restart() - Restart discovery
 215  * @disc: The discovery object to be restarted
 216  *
 217  * Locking Note: This function expects that the disc mutex
 218  *               is already locked.
 219  */
 220 static void fc_disc_restart(struct fc_disc *disc)
 221 {
 222         if (!disc->disc_callback)
 223                 return;
 224
 225         FC_DISC_DBG(disc, "Restarting discovery\n");
 226
 227         disc->requested = 1;
 228         if (disc->pending)
 229                 return;
 230
 231         /*
 232          * Advance disc_id.  This is an arbitrary non-zero number that will
 233          * match the value in the fc_rport_priv after discovery for all
 234          * freshly-discovered remote ports.  Avoid wrapping to zero.
 235          */
 236         disc->disc_id = (disc->disc_id + 2) | 1;
 237         disc->retry_count = 0;
 238         fc_disc_gpn_ft_req(disc);
 239 }
 240
 241 /**
 242  * fc_disc_start() - Start discovery on a local port
 243  * @lport:         The local port to have discovery started on
 244  * @disc_callback: Callback function to be called when discovery is complete
 245  */
 246 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
 247                                                 enum fc_disc_event),
 248                           struct fc_lport *lport)
 249 {
 250         struct fc_disc *disc = &lport->disc;
 251
 252         /*
 253          * At this point we may have a new disc job or an existing
 254          * one. Either way, let's lock when we make changes to it
 255          * and send the GPN_FT request.
 256          */
 257         mutex_lock(&disc->disc_mutex);
 258         disc->disc_callback = disc_callback;
 259         fc_disc_restart(disc);
 260         mutex_unlock(&disc->disc_mutex);
 261 }
 262
 263 /**
 264  * fc_disc_done() - Discovery has been completed
 265  * @disc:  The discovery context
 266  * @event: The discovery completion status
 267  *
 268  * Locking Note: This function expects that the disc mutex is locked before
 269  * it is called. The discovery callback is then made with the lock released,
 270  * and the lock is re-taken before returning from this function
 271  */
 272 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
 273 {
 274         struct fc_lport *lport = fc_disc_lport(disc);
 275         struct fc_rport_priv *rdata;
 276
 277         FC_DISC_DBG(disc, "Discovery complete\n");
 278
 279         disc->pending = 0;
 280         if (disc->requested) {
 281                 fc_disc_restart(disc);
 282                 return;
 283         }
 284
 285         /*
 286          * Go through all remote ports.  If they were found in the latest
 287          * discovery, reverify or log them in.  Otherwise, log them out.
 288          * Skip ports which were never discovered.  These are the dNS port
 289          * and ports which were created by PLOGI.
 290          */
 291         list_for_each_entry_rcu(rdata, &disc->rports, peers) {
 292                 if (!rdata->disc_id)
 293                         continue;
 294                 if (rdata->disc_id == disc->disc_id)
 295                         lport->tt.rport_login(rdata);
 296                 else
 297                         lport->tt.rport_logoff(rdata);
 298         }
 299
 300         mutex_unlock(&disc->disc_mutex);
 301         disc->disc_callback(lport, event);
 302         mutex_lock(&disc->disc_mutex);
 303 }
 304
 305 /**
 306  * fc_disc_error() - Handle error on dNS request
 307  * @disc: The discovery context
 308  * @fp:   The error code encoded as a frame pointer
 309  */
 310 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
 311 {
 312         struct fc_lport *lport = fc_disc_lport(disc);
 313         unsigned long delay = 0;
 314
 315         FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
 316                     PTR_ERR(fp), disc->retry_count,
 317                     FC_DISC_RETRY_LIMIT);
 318
 319         if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
 320                 /*
 321                  * Memory allocation failure, or the exchange timed out,
 322                  * retry after delay.
 323                  */
 324                 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
 325                         /* go ahead and retry */
 326                         if (!fp)
 327                                 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
 328                         else {
 329                                 delay = msecs_to_jiffies(lport->e_d_tov);
 330
 331                                 /* timeout faster first time */
 332                                 if (!disc->retry_count)
 333                                         delay /= 4;
 334                         }
 335                         disc->retry_count++;
 336                         schedule_delayed_work(&disc->disc_work, delay);
 337                 } else
 338                         fc_disc_done(disc, DISC_EV_FAILED);
 339         }
 340 }
 341
 342 /**
 343  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
 344  * @lport: The discovery context
 345  *
 346  * Locking Note: This function expects that the disc_mutex is locked
 347  *               before it is called.
 348  */
 349 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
 350 {
 351         struct fc_frame *fp;
 352         struct fc_lport *lport = fc_disc_lport(disc);
 353
 354         WARN_ON(!fc_lport_test_ready(lport));
 355
 356         disc->pending = 1;
 357         disc->requested = 0;
 358
 359         disc->buf_len = 0;
 360         disc->seq_count = 0;
 361         fp = fc_frame_alloc(lport,
 362                             sizeof(struct fc_ct_hdr) +
 363                             sizeof(struct fc_ns_gid_ft));
 364         if (!fp)
 365                 goto err;
 366
 367         if (lport->tt.elsct_send(lport, 0, fp,
 368                                  FC_NS_GPN_FT,
 369                                  fc_disc_gpn_ft_resp,
 370                                  disc, 3 * lport->r_a_tov))
 371                 return;
 372 err:
 373         fc_disc_error(disc, NULL);
 374 }
 375
 376 /**
 377  * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
 378  * @lport: The local port the GPN_FT was received on
 379  * @buf:   The GPN_FT response buffer
 380  * @len:   The size of response buffer
 381  *
 382  * Goes through the list of IDs and names resulting from a request.
 383  */
 384 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
 385 {
 386         struct fc_lport *lport;
 387         struct fc_gpn_ft_resp *np;
 388         char *bp;
 389         size_t plen;
 390         size_t tlen;
 391         int error = 0;
 392         struct fc_rport_identifiers ids;
 393         struct fc_rport_priv *rdata;
 394
 395         lport = fc_disc_lport(disc);
 396         disc->seq_count++;
 397
 398         /*
 399          * Handle partial name record left over from previous call.
 400          */
 401         bp = buf;
 402         plen = len;
 403         np = (struct fc_gpn_ft_resp *)bp;
 404         tlen = disc->buf_len;
 405         disc->buf_len = 0;
 406         if (tlen) {
 407                 WARN_ON(tlen >= sizeof(*np));
 408                 plen = sizeof(*np) - tlen;
 409                 WARN_ON(plen <= 0);
 410                 WARN_ON(plen >= sizeof(*np));
 411                 if (plen > len)
 412                         plen = len;
 413                 np = &disc->partial_buf;
 414                 memcpy((char *)np + tlen, bp, plen);
 415
 416                 /*
 417                  * Set bp so that the loop below will advance it to the
 418                  * first valid full name element.
 419                  */
 420                 bp -= tlen;
 421                 len += tlen;
 422                 plen += tlen;
 423                 disc->buf_len = (unsigned char) plen;
 424                 if (plen == sizeof(*np))
 425                         disc->buf_len = 0;
 426         }
 427
 428         /*
 429          * Handle full name records, including the one filled from above.
 430          * Normally, np == bp and plen == len, but from the partial case above,
 431          * bp, len describe the overall buffer, and np, plen describe the
 432          * partial buffer, which if would usually be full now.
 433          * After the first time through the loop, things return to "normal".
 434          */
 435         while (plen >= sizeof(*np)) {
 436                 ids.port_id = ntoh24(np->fp_fid);
 437                 ids.port_name = ntohll(np->fp_wwpn);
 438
 439                 if (ids.port_id != lport->port_id &&
 440                     ids.port_name != lport->wwpn) {
 441                         rdata = lport->tt.rport_create(lport, ids.port_id);
 442                         if (rdata) {
 443                                 rdata->ids.port_name = ids.port_name;
 444                                 rdata->disc_id = disc->disc_id;
 445                         } else {
 446                                 printk(KERN_WARNING "libfc: Failed to allocate "
 447                                        "memory for the newly discovered port "
 448                                        "(%6.6x)\n", ids.port_id);
 449                                 error = -ENOMEM;
 450                         }
 451                 }
 452
 453                 if (np->fp_flags & FC_NS_FID_LAST) {
 454                         fc_disc_done(disc, DISC_EV_SUCCESS);
 455                         len = 0;
 456                         break;
 457                 }
 458                 len -= sizeof(*np);
 459                 bp += sizeof(*np);
 460                 np = (struct fc_gpn_ft_resp *)bp;
 461                 plen = len;
 462         }
 463
 464         /*
 465          * Save any partial record at the end of the buffer for next time.
 466          */
 467         if (error == 0 && len > 0 && len < sizeof(*np)) {
 468                 if (np != &disc->partial_buf) {
 469                         FC_DISC_DBG(disc, "Partial buffer remains "
 470                                     "for discovery\n");
 471                         memcpy(&disc->partial_buf, np, len);
 472                 }
 473                 disc->buf_len = (unsigned char) len;
 474         }
 475         return error;
 476 }
 477
 478 /**
 479  * fc_disc_timeout() - Handler for discovery timeouts
 480  * @work: Structure holding discovery context that needs to retry discovery
 481  */
 482 static void fc_disc_timeout(struct work_struct *work)
 483 {
 484         struct fc_disc *disc = container_of(work,
 485                                             struct fc_disc,
 486                                             disc_work.work);
 487         mutex_lock(&disc->disc_mutex);
 488         fc_disc_gpn_ft_req(disc);
 489         mutex_unlock(&disc->disc_mutex);
 490 }
 491
 492 /**
 493  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
 494  * @sp:     The sequence that the GPN_FT response was received on
 495  * @fp:     The GPN_FT response frame
 496  * @lp_arg: The discovery context
 497  *
 498  * Locking Note: This function is called without disc mutex held, and
 499  *               should do all its processing with the mutex held
 500  */
 501 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
 502                                 void *disc_arg)
 503 {
 504         struct fc_disc *disc = disc_arg;
 505         struct fc_ct_hdr *cp;
 506         struct fc_frame_header *fh;
 507         enum fc_disc_event event = DISC_EV_NONE;
 508         unsigned int seq_cnt;
 509         unsigned int len;
 510         int error = 0;
 511
 512         mutex_lock(&disc->disc_mutex);
 513         FC_DISC_DBG(disc, "Received a GPN_FT response\n");
 514
 515         if (IS_ERR(fp)) {
 516                 fc_disc_error(disc, fp);
 517                 mutex_unlock(&disc->disc_mutex);
 518                 return;
 519         }
 520
 521         WARN_ON(!fc_frame_is_linear(fp));       /* buffer must be contiguous */
 522         fh = fc_frame_header_get(fp);
 523         len = fr_len(fp) - sizeof(*fh);
 524         seq_cnt = ntohs(fh->fh_seq_cnt);
 525         if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
 526                 cp = fc_frame_payload_get(fp, sizeof(*cp));
 527                 if (!cp) {
 528                         FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
 529                                     fr_len(fp));
 530                         event = DISC_EV_FAILED;
 531                 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 532
 533                         /* Accepted, parse the response. */
 534                         len -= sizeof(*cp);
 535                         error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
 536                 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 537                         FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
 538                                     "(check zoning)\n", cp->ct_reason,
 539                                     cp->ct_explan);
 540                         event = DISC_EV_FAILED;
 541                         if (cp->ct_reason == FC_FS_RJT_UNABL &&
 542                             cp->ct_explan == FC_FS_EXP_FTNR)
 543                                 event = DISC_EV_SUCCESS;
 544                 } else {
 545                         FC_DISC_DBG(disc, "GPN_FT unexpected response code "
 546                                     "%x\n", ntohs(cp->ct_cmd));
 547                         event = DISC_EV_FAILED;
 548                 }
 549         } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
 550                 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
 551         } else {
 552                 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
 553                             "seq_cnt %x expected %x sof %x eof %x\n",
 554                             seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
 555                 event = DISC_EV_FAILED;
 556         }
 557         if (error)
 558                 fc_disc_error(disc, fp);
 559         else if (event != DISC_EV_NONE)
 560                 fc_disc_done(disc, event);
 561         fc_frame_free(fp);
 562         mutex_unlock(&disc->disc_mutex);
 563 }
 564
 565 /**
 566  * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
 567  * @sp:        The sequence the GPN_ID is on
 568  * @fp:        The response frame
 569  * @rdata_arg: The remote port that sent the GPN_ID response
 570  *
 571  * Locking Note: This function is called without disc mutex held.
 572  */
 573 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
 574                                 void *rdata_arg)
 575 {
 576         struct fc_rport_priv *rdata = rdata_arg;
 577         struct fc_rport_priv *new_rdata;
 578         struct fc_lport *lport;
 579         struct fc_disc *disc;
 580         struct fc_ct_hdr *cp;
 581         struct fc_ns_gid_pn *pn;
 582         u64 port_name;
 583
 584         lport = rdata->local_port;
 585         disc = &lport->disc;
 586
 587         mutex_lock(&disc->disc_mutex);
 588         if (PTR_ERR(fp) == -FC_EX_CLOSED)
 589                 goto out;
 590         if (IS_ERR(fp))
 591                 goto redisc;
 592
 593         cp = fc_frame_payload_get(fp, sizeof(*cp));
 594         if (!cp)
 595                 goto redisc;
 596         if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 597                 if (fr_len(fp) < sizeof(struct fc_frame_header) +
 598                     sizeof(*cp) + sizeof(*pn))
 599                         goto redisc;
 600                 pn = (struct fc_ns_gid_pn *)(cp + 1);
 601                 port_name = get_unaligned_be64(&pn->fn_wwpn);
 602                 if (rdata->ids.port_name == -1)
 603                         rdata->ids.port_name = port_name;
 604                 else if (rdata->ids.port_name != port_name) {
 605                         FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
 606                                     "Port-id %6.6x wwpn %16.16llx\n",
 607                                     rdata->ids.port_id, port_name);
 608                         lport->tt.rport_logoff(rdata);
 609
 610                         new_rdata = lport->tt.rport_create(lport,
 611                                                            rdata->ids.port_id);
 612                         if (new_rdata) {
 613                                 new_rdata->disc_id = disc->disc_id;
 614                                 lport->tt.rport_login(new_rdata);
 615                         }
 616                         goto out;
 617                 }
 618                 rdata->disc_id = disc->disc_id;
 619                 lport->tt.rport_login(rdata);
 620         } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 621                 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
 622                             cp->ct_reason, cp->ct_explan);
 623                 lport->tt.rport_logoff(rdata);
 624         } else {
 625                 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
 626                             ntohs(cp->ct_cmd));
 627 redisc:
 628                 fc_disc_restart(disc);
 629         }
 630 out:
 631         mutex_unlock(&disc->disc_mutex);
 632         kref_put(&rdata->kref, lport->tt.rport_destroy);
 633 }
 634
 635 /**
 636  * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
 637  * @lport: The local port to initiate discovery on
 638  * @rdata: remote port private data
 639  *
 640  * Locking Note: This function expects that the disc_mutex is locked
 641  *               before it is called.
 642  * On failure, an error code is returned.
 643  */
 644 static int fc_disc_gpn_id_req(struct fc_lport *lport,
 645                               struct fc_rport_priv *rdata)
 646 {
 647         struct fc_frame *fp;
 648
 649         fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
 650                             sizeof(struct fc_ns_fid));
 651         if (!fp)
 652                 return -ENOMEM;
 653         if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
 654                                   fc_disc_gpn_id_resp, rdata,
 655                                   3 * lport->r_a_tov))
 656                 return -ENOMEM;
 657         kref_get(&rdata->kref);
 658         return 0;
 659 }
 660
 661 /**
 662  * fc_disc_single() - Discover the directory information for a single target
 663  * @lport: The local port the remote port is associated with
 664  * @dp:    The port to rediscover
 665  *
 666  * Locking Note: This function expects that the disc_mutex is locked
 667  *               before it is called.
 668  */
 669 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
 670 {
 671         struct fc_rport_priv *rdata;
 672
 673         rdata = lport->tt.rport_create(lport, dp->port_id);
 674         if (!rdata)
 675                 return -ENOMEM;
 676         rdata->disc_id = 0;
 677         return fc_disc_gpn_id_req(lport, rdata);
 678 }
 679
 680 /**
 681  * fc_disc_stop() - Stop discovery for a given lport
 682  * @lport: The local port that discovery should stop on
 683  */
 684 void fc_disc_stop(struct fc_lport *lport)
 685 {
 686         struct fc_disc *disc = &lport->disc;
 687
 688         if (disc->pending)
 689                 cancel_delayed_work_sync(&disc->disc_work);
 690         fc_disc_stop_rports(disc);
 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);