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 <linux/export.h>
  39 #include <asm/unaligned.h>
  40
  41 #include <scsi/fc/fc_gs.h>
  42
  43 #include <scsi/libfc.h>
  44
  45 #include "fc_libfc.h"
  46
  47 #define FC_DISC_RETRY_LIMIT     3       /* max retries */
  48 #define FC_DISC_RETRY_DELAY     500UL   /* (msecs) delay */
  49
  50 static void fc_disc_gpn_ft_req(struct fc_disc *);
  51 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
  52 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
  53 static void fc_disc_timeout(struct work_struct *);
  54 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
  55 static void fc_disc_restart(struct fc_disc *);
  56
  57 /**
  58  * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
  59  * @disc: The discovery job to stop remote ports on
  60  *
  61  * Locking Note: This function expects that the lport mutex is locked before
  62  * calling it.
  63  */
  64 void fc_disc_stop_rports(struct fc_disc *disc)
  65 {
  66         struct fc_lport *lport;
  67         struct fc_rport_priv *rdata;
  68
  69         lport = fc_disc_lport(disc);
  70
  71         mutex_lock(&disc->disc_mutex);
  72         list_for_each_entry_rcu(rdata, &disc->rports, peers)
  73                 lport->tt.rport_logoff(rdata);
  74         mutex_unlock(&disc->disc_mutex);
  75 }
  76
  77 /**
  78  * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
  79  * @disc:  The discovery object to which the RSCN applies
  80  * @fp:    The RSCN frame
  81  *
  82  * Locking Note: This function expects that the disc_mutex is locked
  83  *               before it is called.
  84  */
  85 static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
  86 {
  87         struct fc_lport *lport;
  88         struct fc_els_rscn *rp;
  89         struct fc_els_rscn_page *pp;
  90         struct fc_seq_els_data rjt_data;
  91         unsigned int len;
  92         int redisc = 0;
  93         enum fc_els_rscn_ev_qual ev_qual;
  94         enum fc_els_rscn_addr_fmt fmt;
  95         LIST_HEAD(disc_ports);
  96         struct fc_disc_port *dp, *next;
  97
  98         lport = fc_disc_lport(disc);
  99
 100         FC_DISC_DBG(disc, "Received an RSCN event\n");
 101
 102         /* make sure the frame contains an RSCN message */
 103         rp = fc_frame_payload_get(fp, sizeof(*rp));
 104         if (!rp)
 105                 goto reject;
 106         /* make sure the page length is as expected (4 bytes) */
 107         if (rp->rscn_page_len != sizeof(*pp))
 108                 goto reject;
 109         /* get the RSCN payload length */
 110         len = ntohs(rp->rscn_plen);
 111         if (len < sizeof(*rp))
 112                 goto reject;
 113         /* make sure the frame contains the expected payload */
 114         rp = fc_frame_payload_get(fp, len);
 115         if (!rp)
 116                 goto reject;
 117         /* payload must be a multiple of the RSCN page size */
 118         len -= sizeof(*rp);
 119         if (len % sizeof(*pp))
 120                 goto reject;
 121
 122         for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
 123                 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
 124                 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
 125                 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
 126                 fmt &= ELS_RSCN_ADDR_FMT_MASK;
 127                 /*
 128                  * if we get an address format other than port
 129                  * (area, domain, fabric), then do a full discovery
 130                  */
 131                 switch (fmt) {
 132                 case ELS_ADDR_FMT_PORT:
 133                         FC_DISC_DBG(disc, "Port address format for port "
 134                                     "(%6.6x)\n", ntoh24(pp->rscn_fid));
 135                         dp = kzalloc(sizeof(*dp), GFP_KERNEL);
 136                         if (!dp) {
 137                                 redisc = 1;
 138                                 break;
 139                         }
 140                         dp->lp = lport;
 141                         dp->port_id = ntoh24(pp->rscn_fid);
 142                         list_add_tail(&dp->peers, &disc_ports);
 143                         break;
 144                 case ELS_ADDR_FMT_AREA:
 145                 case ELS_ADDR_FMT_DOM:
 146                 case ELS_ADDR_FMT_FAB:
 147                 default:
 148                         FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
 149                         redisc = 1;
 150                         break;
 151                 }
 152         }
 153         lport->tt.seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
 154
 155         /*
 156          * If not doing a complete rediscovery, do GPN_ID on
 157          * the individual ports mentioned in the list.
 158          * If any of these get an error, do a full rediscovery.
 159          * In any case, go through the list and free the entries.
 160          */
 161         list_for_each_entry_safe(dp, next, &disc_ports, peers) {
 162                 list_del(&dp->peers);
 163                 if (!redisc)
 164                         redisc = fc_disc_single(lport, dp);
 165                 kfree(dp);
 166         }
 167         if (redisc) {
 168                 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
 169                 fc_disc_restart(disc);
 170         } else {
 171                 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
 172                             "redisc %d state %d in_prog %d\n",
 173                             redisc, lport->state, disc->pending);
 174         }
 175         fc_frame_free(fp);
 176         return;
 177 reject:
 178         FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
 179         rjt_data.reason = ELS_RJT_LOGIC;
 180         rjt_data.explan = ELS_EXPL_NONE;
 181         lport->tt.seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
 182         fc_frame_free(fp);
 183 }
 184
 185 /**
 186  * fc_disc_recv_req() - Handle incoming requests
 187  * @lport: The local port receiving the request
 188  * @fp:    The request frame
 189  *
 190  * Locking Note: This function is called from the EM and will lock
 191  *               the disc_mutex before calling the handler for the
 192  *               request.
 193  */
 194 static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
 195 {
 196         u8 op;
 197         struct fc_disc *disc = &lport->disc;
 198
 199         op = fc_frame_payload_op(fp);
 200         switch (op) {
 201         case ELS_RSCN:
 202                 mutex_lock(&disc->disc_mutex);
 203                 fc_disc_recv_rscn_req(disc, fp);
 204                 mutex_unlock(&disc->disc_mutex);
 205                 break;
 206         default:
 207                 FC_DISC_DBG(disc, "Received an unsupported request, "
 208                             "the opcode is (%x)\n", op);
 209                 fc_frame_free(fp);
 210                 break;
 211         }
 212 }
 213
 214 /**
 215  * fc_disc_restart() - Restart discovery
 216  * @disc: The discovery object to be restarted
 217  *
 218  * Locking Note: This function expects that the disc mutex
 219  *               is already locked.
 220  */
 221 static void fc_disc_restart(struct fc_disc *disc)
 222 {
 223         if (!disc->disc_callback)
 224                 return;
 225
 226         FC_DISC_DBG(disc, "Restarting discovery\n");
 227
 228         disc->requested = 1;
 229         if (disc->pending)
 230                 return;
 231
 232         /*
 233          * Advance disc_id.  This is an arbitrary non-zero number that will
 234          * match the value in the fc_rport_priv after discovery for all
 235          * freshly-discovered remote ports.  Avoid wrapping to zero.
 236          */
 237         disc->disc_id = (disc->disc_id + 2) | 1;
 238         disc->retry_count = 0;
 239         fc_disc_gpn_ft_req(disc);
 240 }
 241
 242 /**
 243  * fc_disc_start() - Start discovery on a local port
 244  * @lport:         The local port to have discovery started on
 245  * @disc_callback: Callback function to be called when discovery is complete
 246  */
 247 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
 248                                                 enum fc_disc_event),
 249                           struct fc_lport *lport)
 250 {
 251         struct fc_disc *disc = &lport->disc;
 252
 253         /*
 254          * At this point we may have a new disc job or an existing
 255          * one. Either way, let's lock when we make changes to it
 256          * and send the GPN_FT request.
 257          */
 258         mutex_lock(&disc->disc_mutex);
 259         disc->disc_callback = disc_callback;
 260         fc_disc_restart(disc);
 261         mutex_unlock(&disc->disc_mutex);
 262 }
 263
 264 /**
 265  * fc_disc_done() - Discovery has been completed
 266  * @disc:  The discovery context
 267  * @event: The discovery completion status
 268  *
 269  * Locking Note: This function expects that the disc mutex is locked before
 270  * it is called. The discovery callback is then made with the lock released,
 271  * and the lock is re-taken before returning from this function
 272  */
 273 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
 274 {
 275         struct fc_lport *lport = fc_disc_lport(disc);
 276         struct fc_rport_priv *rdata;
 277
 278         FC_DISC_DBG(disc, "Discovery complete\n");
 279
 280         disc->pending = 0;
 281         if (disc->requested) {
 282                 fc_disc_restart(disc);
 283                 return;
 284         }
 285
 286         /*
 287          * Go through all remote ports.  If they were found in the latest
 288          * discovery, reverify or log them in.  Otherwise, log them out.
 289          * Skip ports which were never discovered.  These are the dNS port
 290          * and ports which were created by PLOGI.
 291          */
 292         list_for_each_entry_rcu(rdata, &disc->rports, peers) {
 293                 if (!rdata->disc_id)
 294                         continue;
 295                 if (rdata->disc_id == disc->disc_id)
 296                         lport->tt.rport_login(rdata);
 297                 else
 298                         lport->tt.rport_logoff(rdata);
 299         }
 300
 301         mutex_unlock(&disc->disc_mutex);
 302         disc->disc_callback(lport, event);
 303         mutex_lock(&disc->disc_mutex);
 304 }
 305
 306 /**
 307  * fc_disc_error() - Handle error on dNS request
 308  * @disc: The discovery context
 309  * @fp:   The error code encoded as a frame pointer
 310  */
 311 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
 312 {
 313         struct fc_lport *lport = fc_disc_lport(disc);
 314         unsigned long delay = 0;
 315
 316         FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
 317                     PTR_ERR(fp), disc->retry_count,
 318                     FC_DISC_RETRY_LIMIT);
 319
 320         if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
 321                 /*
 322                  * Memory allocation failure, or the exchange timed out,
 323                  * retry after delay.
 324                  */
 325                 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
 326                         /* go ahead and retry */
 327                         if (!fp)
 328                                 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
 329                         else {
 330                                 delay = msecs_to_jiffies(lport->e_d_tov);
 331
 332                                 /* timeout faster first time */
 333                                 if (!disc->retry_count)
 334                                         delay /= 4;
 335                         }
 336                         disc->retry_count++;
 337                         schedule_delayed_work(&disc->disc_work, delay);
 338                 } else
 339                         fc_disc_done(disc, DISC_EV_FAILED);
 340         }
 341 }
 342
 343 /**
 344  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
 345  * @lport: The discovery context
 346  *
 347  * Locking Note: This function expects that the disc_mutex is locked
 348  *               before it is called.
 349  */
 350 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
 351 {
 352         struct fc_frame *fp;
 353         struct fc_lport *lport = fc_disc_lport(disc);
 354
 355         WARN_ON(!fc_lport_test_ready(lport));
 356
 357         disc->pending = 1;
 358         disc->requested = 0;
 359
 360         disc->buf_len = 0;
 361         disc->seq_count = 0;
 362         fp = fc_frame_alloc(lport,
 363                             sizeof(struct fc_ct_hdr) +
 364                             sizeof(struct fc_ns_gid_ft));
 365         if (!fp)
 366                 goto err;
 367
 368         if (lport->tt.elsct_send(lport, 0, fp,
 369                                  FC_NS_GPN_FT,
 370                                  fc_disc_gpn_ft_resp,
 371                                  disc, 3 * lport->r_a_tov))
 372                 return;
 373 err:
 374         fc_disc_error(disc, NULL);
 375 }
 376
 377 /**
 378  * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
 379  * @lport: The local port the GPN_FT was received on
 380  * @buf:   The GPN_FT response buffer
 381  * @len:   The size of response buffer
 382  *
 383  * Goes through the list of IDs and names resulting from a request.
 384  */
 385 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
 386 {
 387         struct fc_lport *lport;
 388         struct fc_gpn_ft_resp *np;
 389         char *bp;
 390         size_t plen;
 391         size_t tlen;
 392         int error = 0;
 393         struct fc_rport_identifiers ids;
 394         struct fc_rport_priv *rdata;
 395
 396         lport = fc_disc_lport(disc);
 397         disc->seq_count++;
 398
 399         /*
 400          * Handle partial name record left over from previous call.
 401          */
 402         bp = buf;
 403         plen = len;
 404         np = (struct fc_gpn_ft_resp *)bp;
 405         tlen = disc->buf_len;
 406         disc->buf_len = 0;
 407         if (tlen) {
 408                 WARN_ON(tlen >= sizeof(*np));
 409                 plen = sizeof(*np) - tlen;
 410                 WARN_ON(plen <= 0);
 411                 WARN_ON(plen >= sizeof(*np));
 412                 if (plen > len)
 413                         plen = len;
 414                 np = &disc->partial_buf;
 415                 memcpy((char *)np + tlen, bp, plen);
 416
 417                 /*
 418                  * Set bp so that the loop below will advance it to the
 419                  * first valid full name element.
 420                  */
 421                 bp -= tlen;
 422                 len += tlen;
 423                 plen += tlen;
 424                 disc->buf_len = (unsigned char) plen;
 425                 if (plen == sizeof(*np))
 426                         disc->buf_len = 0;
 427         }
 428
 429         /*
 430          * Handle full name records, including the one filled from above.
 431          * Normally, np == bp and plen == len, but from the partial case above,
 432          * bp, len describe the overall buffer, and np, plen describe the
 433          * partial buffer, which if would usually be full now.
 434          * After the first time through the loop, things return to "normal".
 435          */
 436         while (plen >= sizeof(*np)) {
 437                 ids.port_id = ntoh24(np->fp_fid);
 438                 ids.port_name = ntohll(np->fp_wwpn);
 439
 440                 if (ids.port_id != lport->port_id &&
 441                     ids.port_name != lport->wwpn) {
 442                         rdata = lport->tt.rport_create(lport, ids.port_id);
 443                         if (rdata) {
 444                                 rdata->ids.port_name = ids.port_name;
 445                                 rdata->disc_id = disc->disc_id;
 446                         } else {
 447                                 printk(KERN_WARNING "libfc: Failed to allocate "
 448                                        "memory for the newly discovered port "
 449                                        "(%6.6x)\n", ids.port_id);
 450                                 error = -ENOMEM;
 451                         }
 452                 }
 453
 454                 if (np->fp_flags & FC_NS_FID_LAST) {
 455                         fc_disc_done(disc, DISC_EV_SUCCESS);
 456                         len = 0;
 457                         break;
 458                 }
 459                 len -= sizeof(*np);
 460                 bp += sizeof(*np);
 461                 np = (struct fc_gpn_ft_resp *)bp;
 462                 plen = len;
 463         }
 464
 465         /*
 466          * Save any partial record at the end of the buffer for next time.
 467          */
 468         if (error == 0 && len > 0 && len < sizeof(*np)) {
 469                 if (np != &disc->partial_buf) {
 470                         FC_DISC_DBG(disc, "Partial buffer remains "
 471                                     "for discovery\n");
 472                         memcpy(&disc->partial_buf, np, len);
 473                 }
 474                 disc->buf_len = (unsigned char) len;
 475         }
 476         return error;
 477 }
 478
 479 /**
 480  * fc_disc_timeout() - Handler for discovery timeouts
 481  * @work: Structure holding discovery context that needs to retry discovery
 482  */
 483 static void fc_disc_timeout(struct work_struct *work)
 484 {
 485         struct fc_disc *disc = container_of(work,
 486                                             struct fc_disc,
 487                                             disc_work.work);
 488         mutex_lock(&disc->disc_mutex);
 489         fc_disc_gpn_ft_req(disc);
 490         mutex_unlock(&disc->disc_mutex);
 491 }
 492
 493 /**
 494  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
 495  * @sp:     The sequence that the GPN_FT response was received on
 496  * @fp:     The GPN_FT response frame
 497  * @lp_arg: The discovery context
 498  *
 499  * Locking Note: This function is called without disc mutex held, and
 500  *               should do all its processing with the mutex held
 501  */
 502 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
 503                                 void *disc_arg)
 504 {
 505         struct fc_disc *disc = disc_arg;
 506         struct fc_ct_hdr *cp;
 507         struct fc_frame_header *fh;
 508         enum fc_disc_event event = DISC_EV_NONE;
 509         unsigned int seq_cnt;
 510         unsigned int len;
 511         int error = 0;
 512
 513         mutex_lock(&disc->disc_mutex);
 514         FC_DISC_DBG(disc, "Received a GPN_FT response\n");
 515
 516         if (IS_ERR(fp)) {
 517                 fc_disc_error(disc, fp);
 518                 mutex_unlock(&disc->disc_mutex);
 519                 return;
 520         }
 521
 522         WARN_ON(!fc_frame_is_linear(fp));       /* buffer must be contiguous */
 523         fh = fc_frame_header_get(fp);
 524         len = fr_len(fp) - sizeof(*fh);
 525         seq_cnt = ntohs(fh->fh_seq_cnt);
 526         if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
 527                 cp = fc_frame_payload_get(fp, sizeof(*cp));
 528                 if (!cp) {
 529                         FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
 530                                     fr_len(fp));
 531                         event = DISC_EV_FAILED;
 532                 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 533
 534                         /* Accepted, parse the response. */
 535                         len -= sizeof(*cp);
 536                         error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
 537                 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 538                         FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
 539                                     "(check zoning)\n", cp->ct_reason,
 540                                     cp->ct_explan);
 541                         event = DISC_EV_FAILED;
 542                         if (cp->ct_reason == FC_FS_RJT_UNABL &&
 543                             cp->ct_explan == FC_FS_EXP_FTNR)
 544                                 event = DISC_EV_SUCCESS;
 545                 } else {
 546                         FC_DISC_DBG(disc, "GPN_FT unexpected response code "
 547                                     "%x\n", ntohs(cp->ct_cmd));
 548                         event = DISC_EV_FAILED;
 549                 }
 550         } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
 551                 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
 552         } else {
 553                 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
 554                             "seq_cnt %x expected %x sof %x eof %x\n",
 555                             seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
 556                 event = DISC_EV_FAILED;
 557         }
 558         if (error)
 559                 fc_disc_error(disc, fp);
 560         else if (event != DISC_EV_NONE)
 561                 fc_disc_done(disc, event);
 562         fc_frame_free(fp);
 563         mutex_unlock(&disc->disc_mutex);
 564 }
 565
 566 /**
 567  * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
 568  * @sp:        The sequence the GPN_ID is on
 569  * @fp:        The response frame
 570  * @rdata_arg: The remote port that sent the GPN_ID response
 571  *
 572  * Locking Note: This function is called without disc mutex held.
 573  */
 574 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
 575                                 void *rdata_arg)
 576 {
 577         struct fc_rport_priv *rdata = rdata_arg;
 578         struct fc_rport_priv *new_rdata;
 579         struct fc_lport *lport;
 580         struct fc_disc *disc;
 581         struct fc_ct_hdr *cp;
 582         struct fc_ns_gid_pn *pn;
 583         u64 port_name;
 584
 585         lport = rdata->local_port;
 586         disc = &lport->disc;
 587
 588         mutex_lock(&disc->disc_mutex);
 589         if (PTR_ERR(fp) == -FC_EX_CLOSED)
 590                 goto out;
 591         if (IS_ERR(fp))
 592                 goto redisc;
 593
 594         cp = fc_frame_payload_get(fp, sizeof(*cp));
 595         if (!cp)
 596                 goto redisc;
 597         if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 598                 if (fr_len(fp) < sizeof(struct fc_frame_header) +
 599                     sizeof(*cp) + sizeof(*pn))
 600                         goto redisc;
 601                 pn = (struct fc_ns_gid_pn *)(cp + 1);
 602                 port_name = get_unaligned_be64(&pn->fn_wwpn);
 603                 if (rdata->ids.port_name == -1)
 604                         rdata->ids.port_name = port_name;
 605                 else if (rdata->ids.port_name != port_name) {
 606                         FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
 607                                     "Port-id %6.6x wwpn %16.16llx\n",
 608                                     rdata->ids.port_id, port_name);
 609                         lport->tt.rport_logoff(rdata);
 610
 611                         new_rdata = lport->tt.rport_create(lport,
 612                                                            rdata->ids.port_id);
 613                         if (new_rdata) {
 614                                 new_rdata->disc_id = disc->disc_id;
 615                                 lport->tt.rport_login(new_rdata);
 616                         }
 617                         goto out;
 618                 }
 619                 rdata->disc_id = disc->disc_id;
 620                 lport->tt.rport_login(rdata);
 621         } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 622                 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
 623                             cp->ct_reason, cp->ct_explan);
 624                 lport->tt.rport_logoff(rdata);
 625         } else {
 626                 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
 627                             ntohs(cp->ct_cmd));
 628 redisc:
 629                 fc_disc_restart(disc);
 630         }
 631 out:
 632         mutex_unlock(&disc->disc_mutex);
 633         kref_put(&rdata->kref, lport->tt.rport_destroy);
 634 }
 635
 636 /**
 637  * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
 638  * @lport: The local port to initiate discovery on
 639  * @rdata: remote port private data
 640  *
 641  * Locking Note: This function expects that the disc_mutex is locked
 642  *               before it is called.
 643  * On failure, an error code is returned.
 644  */
 645 static int fc_disc_gpn_id_req(struct fc_lport *lport,
 646                               struct fc_rport_priv *rdata)
 647 {
 648         struct fc_frame *fp;
 649
 650         fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
 651                             sizeof(struct fc_ns_fid));
 652         if (!fp)
 653                 return -ENOMEM;
 654         if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
 655                                   fc_disc_gpn_id_resp, rdata,
 656                                   3 * lport->r_a_tov))
 657                 return -ENOMEM;
 658         kref_get(&rdata->kref);
 659         return 0;
 660 }
 661
 662 /**
 663  * fc_disc_single() - Discover the directory information for a single target
 664  * @lport: The local port the remote port is associated with
 665  * @dp:    The port to rediscover
 666  *
 667  * Locking Note: This function expects that the disc_mutex is locked
 668  *               before it is called.
 669  */
 670 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
 671 {
 672         struct fc_rport_priv *rdata;
 673
 674         rdata = lport->tt.rport_create(lport, dp->port_id);
 675         if (!rdata)
 676                 return -ENOMEM;
 677         rdata->disc_id = 0;
 678         return fc_disc_gpn_id_req(lport, rdata);
 679 }
 680
 681 /**
 682  * fc_disc_stop() - Stop discovery for a given lport
 683  * @lport: The local port that discovery should stop on
 684  */
 685 void fc_disc_stop(struct fc_lport *lport)
 686 {
 687         struct fc_disc *disc = &lport->disc;
 688
 689         if (disc->pending)
 690                 cancel_delayed_work_sync(&disc->disc_work);
 691         fc_disc_stop_rports(disc);
 692 }
 693
 694 /**
 695  * fc_disc_stop_final() - Stop discovery for a given lport
 696  * @lport: The lport that discovery should stop on
 697  *
 698  * This function will block until discovery has been
 699  * completely stopped and all rports have been deleted.
 700  */
 701 void fc_disc_stop_final(struct fc_lport *lport)
 702 {
 703         fc_disc_stop(lport);
 704         lport->tt.rport_flush_queue();
 705 }
 706
 707 /**
 708  * fc_disc_init() - Initialize the discovery layer for a local port
 709  * @lport: The local port that needs the discovery layer to be initialized
 710  */
 711 int fc_disc_init(struct fc_lport *lport)
 712 {
 713         struct fc_disc *disc;
 714
 715         if (!lport->tt.disc_start)
 716                 lport->tt.disc_start = fc_disc_start;
 717
 718         if (!lport->tt.disc_stop)
 719                 lport->tt.disc_stop = fc_disc_stop;
 720
 721         if (!lport->tt.disc_stop_final)
 722                 lport->tt.disc_stop_final = fc_disc_stop_final;
 723
 724         if (!lport->tt.disc_recv_req)
 725                 lport->tt.disc_recv_req = fc_disc_recv_req;
 726
 727         disc = &lport->disc;
 728         INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
 729         mutex_init(&disc->disc_mutex);
 730         INIT_LIST_HEAD(&disc->rports);
 731
 732         disc->priv = lport;
 733
 734         return 0;
 735 }
 736 EXPORT_SYMBOL(fc_disc_init);