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 <linux/rculist.h>
  40
  41 #include <asm/unaligned.h>
  42
  43 #include <scsi/fc/fc_gs.h>
  44
  45 #include <scsi/libfc.h>
  46
  47 #include "fc_libfc.h"
  48
  49 #define FC_DISC_RETRY_LIMIT     3       /* max retries */
  50 #define FC_DISC_RETRY_DELAY     500UL   /* (msecs) delay */
  51
  52 static void fc_disc_gpn_ft_req(struct fc_disc *);
  53 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
  54 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
  55 static void fc_disc_timeout(struct work_struct *);
  56 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
  57 static void fc_disc_restart(struct fc_disc *);
  58
  59 /**
  60  * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
  61  * @disc: The discovery job to stop remote ports on
  62  */
  63 static void fc_disc_stop_rports(struct fc_disc *disc)
  64 {
  65         struct fc_rport_priv *rdata;
  66
  67         lockdep_assert_held(&disc->disc_mutex);
  68
  69         list_for_each_entry(rdata, &disc->rports, peers) {
  70                 if (kref_get_unless_zero(&rdata->kref)) {
  71                         fc_rport_logoff(rdata);
  72                         kref_put(&rdata->kref, fc_rport_destroy);
  73                 }
  74         }
  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 static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
  83 {
  84         struct fc_lport *lport;
  85         struct fc_els_rscn *rp;
  86         struct fc_els_rscn_page *pp;
  87         struct fc_seq_els_data rjt_data;
  88         unsigned int len;
  89         int redisc = 0;
  90         enum fc_els_rscn_ev_qual ev_qual;
  91         enum fc_els_rscn_addr_fmt fmt;
  92         LIST_HEAD(disc_ports);
  93         struct fc_disc_port *dp, *next;
  94
  95         lockdep_assert_held(&disc->disc_mutex);
  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         fc_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         fc_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 static void fc_disc_restart(struct fc_disc *disc)
 218 {
 219         lockdep_assert_held(&disc->disc_mutex);
 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 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
 268 {
 269         struct fc_lport *lport = fc_disc_lport(disc);
 270         struct fc_rport_priv *rdata;
 271
 272         lockdep_assert_held(&disc->disc_mutex);
 273         FC_DISC_DBG(disc, "Discovery complete\n");
 274
 275         disc->pending = 0;
 276         if (disc->requested) {
 277                 fc_disc_restart(disc);
 278                 return;
 279         }
 280
 281         /*
 282          * Go through all remote ports.  If they were found in the latest
 283          * discovery, reverify or log them in.  Otherwise, log them out.
 284          * Skip ports which were never discovered.  These are the dNS port
 285          * and ports which were created by PLOGI.
 286          *
 287          * We don't need to use the _rcu variant here as the rport list
 288          * is protected by the disc mutex which is already held on entry.
 289          */
 290         list_for_each_entry(rdata, &disc->rports, peers) {
 291                 if (!kref_get_unless_zero(&rdata->kref))
 292                         continue;
 293                 if (rdata->disc_id) {
 294                         if (rdata->disc_id == disc->disc_id)
 295                                 fc_rport_login(rdata);
 296                         else
 297                                 fc_rport_logoff(rdata);
 298                 }
 299                 kref_put(&rdata->kref, fc_rport_destroy);
 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         } else if (PTR_ERR(fp) == -FC_EX_CLOSED) {
 341                 /*
 342                  * if discovery fails due to lport reset, clear
 343                  * pending flag so that subsequent discovery can
 344                  * continue
 345                  */
 346                 disc->pending = 0;
 347         }
 348 }
 349
 350 /**
 351  * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
 352  * @lport: The discovery context
 353  */
 354 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
 355 {
 356         struct fc_frame *fp;
 357         struct fc_lport *lport = fc_disc_lport(disc);
 358
 359         lockdep_assert_held(&disc->disc_mutex);
 360
 361         WARN_ON(!fc_lport_test_ready(lport));
 362
 363         disc->pending = 1;
 364         disc->requested = 0;
 365
 366         disc->buf_len = 0;
 367         disc->seq_count = 0;
 368         fp = fc_frame_alloc(lport,
 369                             sizeof(struct fc_ct_hdr) +
 370                             sizeof(struct fc_ns_gid_ft));
 371         if (!fp)
 372                 goto err;
 373
 374         if (lport->tt.elsct_send(lport, 0, fp,
 375                                  FC_NS_GPN_FT,
 376                                  fc_disc_gpn_ft_resp,
 377                                  disc, 3 * lport->r_a_tov))
 378                 return;
 379 err:
 380         fc_disc_error(disc, NULL);
 381 }
 382
 383 /**
 384  * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
 385  * @lport: The local port the GPN_FT was received on
 386  * @buf:   The GPN_FT response buffer
 387  * @len:   The size of response buffer
 388  *
 389  * Goes through the list of IDs and names resulting from a request.
 390  */
 391 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
 392 {
 393         struct fc_lport *lport;
 394         struct fc_gpn_ft_resp *np;
 395         char *bp;
 396         size_t plen;
 397         size_t tlen;
 398         int error = 0;
 399         struct fc_rport_identifiers ids;
 400         struct fc_rport_priv *rdata;
 401
 402         lport = fc_disc_lport(disc);
 403         disc->seq_count++;
 404
 405         /*
 406          * Handle partial name record left over from previous call.
 407          */
 408         bp = buf;
 409         plen = len;
 410         np = (struct fc_gpn_ft_resp *)bp;
 411         tlen = disc->buf_len;
 412         disc->buf_len = 0;
 413         if (tlen) {
 414                 WARN_ON(tlen >= sizeof(*np));
 415                 plen = sizeof(*np) - tlen;
 416                 WARN_ON(plen <= 0);
 417                 WARN_ON(plen >= sizeof(*np));
 418                 if (plen > len)
 419                         plen = len;
 420                 np = &disc->partial_buf;
 421                 memcpy((char *)np + tlen, bp, plen);
 422
 423                 /*
 424                  * Set bp so that the loop below will advance it to the
 425                  * first valid full name element.
 426                  */
 427                 bp -= tlen;
 428                 len += tlen;
 429                 plen += tlen;
 430                 disc->buf_len = (unsigned char) plen;
 431                 if (plen == sizeof(*np))
 432                         disc->buf_len = 0;
 433         }
 434
 435         /*
 436          * Handle full name records, including the one filled from above.
 437          * Normally, np == bp and plen == len, but from the partial case above,
 438          * bp, len describe the overall buffer, and np, plen describe the
 439          * partial buffer, which if would usually be full now.
 440          * After the first time through the loop, things return to "normal".
 441          */
 442         while (plen >= sizeof(*np)) {
 443                 ids.port_id = ntoh24(np->fp_fid);
 444                 ids.port_name = ntohll(np->fp_wwpn);
 445
 446                 if (ids.port_id != lport->port_id &&
 447                     ids.port_name != lport->wwpn) {
 448                         rdata = fc_rport_create(lport, ids.port_id);
 449                         if (rdata) {
 450                                 rdata->ids.port_name = ids.port_name;
 451                                 rdata->disc_id = disc->disc_id;
 452                         } else {
 453                                 printk(KERN_WARNING "libfc: Failed to allocate "
 454                                        "memory for the newly discovered port "
 455                                        "(%6.6x)\n", ids.port_id);
 456                                 error = -ENOMEM;
 457                         }
 458                 }
 459
 460                 if (np->fp_flags & FC_NS_FID_LAST) {
 461                         fc_disc_done(disc, DISC_EV_SUCCESS);
 462                         len = 0;
 463                         break;
 464                 }
 465                 len -= sizeof(*np);
 466                 bp += sizeof(*np);
 467                 np = (struct fc_gpn_ft_resp *)bp;
 468                 plen = len;
 469         }
 470
 471         /*
 472          * Save any partial record at the end of the buffer for next time.
 473          */
 474         if (error == 0 && len > 0 && len < sizeof(*np)) {
 475                 if (np != &disc->partial_buf) {
 476                         FC_DISC_DBG(disc, "Partial buffer remains "
 477                                     "for discovery\n");
 478                         memcpy(&disc->partial_buf, np, len);
 479                 }
 480                 disc->buf_len = (unsigned char) len;
 481         }
 482         return error;
 483 }
 484
 485 /**
 486  * fc_disc_timeout() - Handler for discovery timeouts
 487  * @work: Structure holding discovery context that needs to retry discovery
 488  */
 489 static void fc_disc_timeout(struct work_struct *work)
 490 {
 491         struct fc_disc *disc = container_of(work,
 492                                             struct fc_disc,
 493                                             disc_work.work);
 494         mutex_lock(&disc->disc_mutex);
 495         fc_disc_gpn_ft_req(disc);
 496         mutex_unlock(&disc->disc_mutex);
 497 }
 498
 499 /**
 500  * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
 501  * @sp:     The sequence that the GPN_FT response was received on
 502  * @fp:     The GPN_FT response frame
 503  * @lp_arg: The discovery context
 504  *
 505  * Locking Note: This function is called without disc mutex held, and
 506  *               should do all its processing with the mutex held
 507  */
 508 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
 509                                 void *disc_arg)
 510 {
 511         struct fc_disc *disc = disc_arg;
 512         struct fc_ct_hdr *cp;
 513         struct fc_frame_header *fh;
 514         enum fc_disc_event event = DISC_EV_NONE;
 515         unsigned int seq_cnt;
 516         unsigned int len;
 517         int error = 0;
 518
 519         mutex_lock(&disc->disc_mutex);
 520         FC_DISC_DBG(disc, "Received a GPN_FT response\n");
 521
 522         if (IS_ERR(fp)) {
 523                 fc_disc_error(disc, fp);
 524                 mutex_unlock(&disc->disc_mutex);
 525                 return;
 526         }
 527
 528         WARN_ON(!fc_frame_is_linear(fp));       /* buffer must be contiguous */
 529         fh = fc_frame_header_get(fp);
 530         len = fr_len(fp) - sizeof(*fh);
 531         seq_cnt = ntohs(fh->fh_seq_cnt);
 532         if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
 533                 cp = fc_frame_payload_get(fp, sizeof(*cp));
 534                 if (!cp) {
 535                         FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
 536                                     fr_len(fp));
 537                         event = DISC_EV_FAILED;
 538                 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 539
 540                         /* Accepted, parse the response. */
 541                         len -= sizeof(*cp);
 542                         error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
 543                 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 544                         FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
 545                                     "(check zoning)\n", cp->ct_reason,
 546                                     cp->ct_explan);
 547                         event = DISC_EV_FAILED;
 548                         if (cp->ct_reason == FC_FS_RJT_UNABL &&
 549                             cp->ct_explan == FC_FS_EXP_FTNR)
 550                                 event = DISC_EV_SUCCESS;
 551                 } else {
 552                         FC_DISC_DBG(disc, "GPN_FT unexpected response code "
 553                                     "%x\n", ntohs(cp->ct_cmd));
 554                         event = DISC_EV_FAILED;
 555                 }
 556         } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
 557                 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
 558         } else {
 559                 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
 560                             "seq_cnt %x expected %x sof %x eof %x\n",
 561                             seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
 562                 event = DISC_EV_FAILED;
 563         }
 564         if (error)
 565                 fc_disc_error(disc, ERR_PTR(error));
 566         else if (event != DISC_EV_NONE)
 567                 fc_disc_done(disc, event);
 568         fc_frame_free(fp);
 569         mutex_unlock(&disc->disc_mutex);
 570 }
 571
 572 /**
 573  * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
 574  * @sp:        The sequence the GPN_ID is on
 575  * @fp:        The response frame
 576  * @rdata_arg: The remote port that sent the GPN_ID response
 577  *
 578  * Locking Note: This function is called without disc mutex held.
 579  */
 580 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
 581                                 void *rdata_arg)
 582 {
 583         struct fc_rport_priv *rdata = rdata_arg;
 584         struct fc_rport_priv *new_rdata;
 585         struct fc_lport *lport;
 586         struct fc_disc *disc;
 587         struct fc_ct_hdr *cp;
 588         struct fc_ns_gid_pn *pn;
 589         u64 port_name;
 590
 591         lport = rdata->local_port;
 592         disc = &lport->disc;
 593
 594         if (PTR_ERR(fp) == -FC_EX_CLOSED)
 595                 goto out;
 596         if (IS_ERR(fp))
 597                 goto redisc;
 598
 599         cp = fc_frame_payload_get(fp, sizeof(*cp));
 600         if (!cp)
 601                 goto redisc;
 602         if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
 603                 if (fr_len(fp) < sizeof(struct fc_frame_header) +
 604                     sizeof(*cp) + sizeof(*pn))
 605                         goto redisc;
 606                 pn = (struct fc_ns_gid_pn *)(cp + 1);
 607                 port_name = get_unaligned_be64(&pn->fn_wwpn);
 608                 mutex_lock(&rdata->rp_mutex);
 609                 if (rdata->ids.port_name == -1)
 610                         rdata->ids.port_name = port_name;
 611                 else if (rdata->ids.port_name != port_name) {
 612                         FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
 613                                     "Port-id %6.6x wwpn %16.16llx\n",
 614                                     rdata->ids.port_id, port_name);
 615                         mutex_unlock(&rdata->rp_mutex);
 616                         fc_rport_logoff(rdata);
 617                         mutex_lock(&lport->disc.disc_mutex);
 618                         new_rdata = fc_rport_create(lport, rdata->ids.port_id);
 619                         mutex_unlock(&lport->disc.disc_mutex);
 620                         if (new_rdata) {
 621                                 new_rdata->disc_id = disc->disc_id;
 622                                 fc_rport_login(new_rdata);
 623                         }
 624                         goto out;
 625                 }
 626                 rdata->disc_id = disc->disc_id;
 627                 mutex_unlock(&rdata->rp_mutex);
 628                 fc_rport_login(rdata);
 629         } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
 630                 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
 631                             cp->ct_reason, cp->ct_explan);
 632                 fc_rport_logoff(rdata);
 633         } else {
 634                 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
 635                             ntohs(cp->ct_cmd));
 636 redisc:
 637                 mutex_lock(&disc->disc_mutex);
 638                 fc_disc_restart(disc);
 639                 mutex_unlock(&disc->disc_mutex);
 640         }
 641 out:
 642         kref_put(&rdata->kref, fc_rport_destroy);
 643 }
 644
 645 /**
 646  * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
 647  * @lport: The local port to initiate discovery on
 648  * @rdata: remote port private data
 649  *
 650  * On failure, an error code is returned.
 651  */
 652 static int fc_disc_gpn_id_req(struct fc_lport *lport,
 653                               struct fc_rport_priv *rdata)
 654 {
 655         struct fc_frame *fp;
 656
 657         lockdep_assert_held(&lport->disc.disc_mutex);
 658         fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
 659                             sizeof(struct fc_ns_fid));
 660         if (!fp)
 661                 return -ENOMEM;
 662         if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
 663                                   fc_disc_gpn_id_resp, rdata,
 664                                   3 * lport->r_a_tov))
 665                 return -ENOMEM;
 666         kref_get(&rdata->kref);
 667         return 0;
 668 }
 669
 670 /**
 671  * fc_disc_single() - Discover the directory information for a single target
 672  * @lport: The local port the remote port is associated with
 673  * @dp:    The port to rediscover
 674  */
 675 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
 676 {
 677         struct fc_rport_priv *rdata;
 678
 679         lockdep_assert_held(&lport->disc.disc_mutex);
 680
 681         rdata = fc_rport_create(lport, dp->port_id);
 682         if (!rdata)
 683                 return -ENOMEM;
 684         rdata->disc_id = 0;
 685         return fc_disc_gpn_id_req(lport, rdata);
 686 }
 687
 688 /**
 689  * fc_disc_stop() - Stop discovery for a given lport
 690  * @lport: The local port that discovery should stop on
 691  */
 692 static void fc_disc_stop(struct fc_lport *lport)
 693 {
 694         struct fc_disc *disc = &lport->disc;
 695
 696         if (disc->pending)
 697                 cancel_delayed_work_sync(&disc->disc_work);
 698         mutex_lock(&disc->disc_mutex);
 699         fc_disc_stop_rports(disc);
 700         mutex_unlock(&disc->disc_mutex);
 701 }
 702
 703 /**
 704  * fc_disc_stop_final() - Stop discovery for a given lport
 705  * @lport: The lport that discovery should stop on
 706  *
 707  * This function will block until discovery has been
 708  * completely stopped and all rports have been deleted.
 709  */
 710 static void fc_disc_stop_final(struct fc_lport *lport)
 711 {
 712         fc_disc_stop(lport);
 713         fc_rport_flush_queue();
 714 }
 715
 716 /**
 717  * fc_disc_config() - Configure the discovery layer for a local port
 718  * @lport: The local port that needs the discovery layer to be configured
 719  * @priv: Private data structre for users of the discovery layer
 720  */
 721 void fc_disc_config(struct fc_lport *lport, void *priv)
 722 {
 723         struct fc_disc *disc;
 724
 725         if (!lport->tt.disc_start)
 726                 lport->tt.disc_start = fc_disc_start;
 727
 728         if (!lport->tt.disc_stop)
 729                 lport->tt.disc_stop = fc_disc_stop;
 730
 731         if (!lport->tt.disc_stop_final)
 732                 lport->tt.disc_stop_final = fc_disc_stop_final;
 733
 734         if (!lport->tt.disc_recv_req)
 735                 lport->tt.disc_recv_req = fc_disc_recv_req;
 736
 737         disc = &lport->disc;
 738
 739         disc->priv = priv;
 740 }
 741 EXPORT_SYMBOL(fc_disc_config);
 742
 743 /**
 744  * fc_disc_init() - Initialize the discovery layer for a local port
 745  * @lport: The local port that needs the discovery layer to be initialized
 746  */
 747 void fc_disc_init(struct fc_lport *lport)
 748 {
 749         struct fc_disc *disc = &lport->disc;
 750
 751         INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
 752         mutex_init(&disc->disc_mutex);
 753         INIT_LIST_HEAD(&disc->rports);
 754 }
 755 EXPORT_SYMBOL(fc_disc_init);