1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
4 *
5 * Maintained at www.Open-FCoE.org
6 */
7
8 /*
9 * Target Discovery
10 *
11 * This block discovers all FC-4 remote ports, including FCP initiators. It
12 * also handles RSCN events and re-discovery if necessary.
13 */
14
15 /*
16 * DISC LOCKING
17 *
18 * The disc mutex is can be locked when acquiring rport locks, but may not
19 * be held when acquiring the lport lock. Refer to fc_lport.c for more
20 * details.
21 */
22
23 #include <linux/timer.h>
24 #include <linux/slab.h>
25 #include <linux/err.h>
26 #include <linux/export.h>
27 #include <linux/list.h>
28
29 #include <linux/unaligned.h>
30
31 #include <scsi/fc/fc_gs.h>
32
33 #include <scsi/libfc.h>
34
35 #include "fc_libfc.h"
36
37 #define FC_DISC_RETRY_LIMIT 3 /* max retries */
38 #define FC_DISC_RETRY_DELAY 500UL /* (msecs) delay */
39
40 static void fc_disc_gpn_ft_req(struct fc_disc *);
41 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
42 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
43 static void fc_disc_timeout(struct work_struct *);
44 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
45 static void fc_disc_restart(struct fc_disc *);
46
47 /**
48 * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
49 * @disc: The discovery job to stop remote ports on
50 */
fc_disc_stop_rports(struct fc_disc * disc)51 static void fc_disc_stop_rports(struct fc_disc *disc)
52 {
53 struct fc_rport_priv *rdata;
54
55 lockdep_assert_held(&disc->disc_mutex);
56
57 list_for_each_entry(rdata, &disc->rports, peers) {
58 if (kref_get_unless_zero(&rdata->kref)) {
59 fc_rport_logoff(rdata);
60 kref_put(&rdata->kref, fc_rport_destroy);
61 }
62 }
63 }
64
65 /**
66 * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
67 * @disc: The discovery object to which the RSCN applies
68 * @fp: The RSCN frame
69 */
fc_disc_recv_rscn_req(struct fc_disc * disc,struct fc_frame * fp)70 static void fc_disc_recv_rscn_req(struct fc_disc *disc, struct fc_frame *fp)
71 {
72 struct fc_lport *lport;
73 struct fc_els_rscn *rp;
74 struct fc_els_rscn_page *pp;
75 struct fc_seq_els_data rjt_data;
76 unsigned int len;
77 int redisc = 0;
78 enum fc_els_rscn_addr_fmt fmt;
79 LIST_HEAD(disc_ports);
80 struct fc_disc_port *dp, *next;
81
82 lockdep_assert_held(&disc->disc_mutex);
83
84 lport = fc_disc_lport(disc);
85
86 FC_DISC_DBG(disc, "Received an RSCN event\n");
87
88 /* make sure the frame contains an RSCN message */
89 rp = fc_frame_payload_get(fp, sizeof(*rp));
90 if (!rp)
91 goto reject;
92 /* make sure the page length is as expected (4 bytes) */
93 if (rp->rscn_page_len != sizeof(*pp))
94 goto reject;
95 /* get the RSCN payload length */
96 len = ntohs(rp->rscn_plen);
97 if (len < sizeof(*rp))
98 goto reject;
99 /* make sure the frame contains the expected payload */
100 rp = fc_frame_payload_get(fp, len);
101 if (!rp)
102 goto reject;
103 /* payload must be a multiple of the RSCN page size */
104 len -= sizeof(*rp);
105 if (len % sizeof(*pp))
106 goto reject;
107
108 for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
109 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
110 fmt &= ELS_RSCN_ADDR_FMT_MASK;
111 /*
112 * if we get an address format other than port
113 * (area, domain, fabric), then do a full discovery
114 */
115 switch (fmt) {
116 case ELS_ADDR_FMT_PORT:
117 FC_DISC_DBG(disc, "Port address format for port "
118 "(%6.6x)\n", ntoh24(pp->rscn_fid));
119 dp = kzalloc(sizeof(*dp), GFP_KERNEL);
120 if (!dp) {
121 redisc = 1;
122 break;
123 }
124 dp->lp = lport;
125 dp->port_id = ntoh24(pp->rscn_fid);
126 list_add_tail(&dp->peers, &disc_ports);
127 break;
128 case ELS_ADDR_FMT_AREA:
129 case ELS_ADDR_FMT_DOM:
130 case ELS_ADDR_FMT_FAB:
131 default:
132 FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
133 redisc = 1;
134 break;
135 }
136 }
137 fc_seq_els_rsp_send(fp, ELS_LS_ACC, NULL);
138
139 /*
140 * If not doing a complete rediscovery, do GPN_ID on
141 * the individual ports mentioned in the list.
142 * If any of these get an error, do a full rediscovery.
143 * In any case, go through the list and free the entries.
144 */
145 list_for_each_entry_safe(dp, next, &disc_ports, peers) {
146 list_del(&dp->peers);
147 if (!redisc)
148 redisc = fc_disc_single(lport, dp);
149 kfree(dp);
150 }
151 if (redisc) {
152 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
153 fc_disc_restart(disc);
154 } else {
155 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
156 "redisc %d state %d in_prog %d\n",
157 redisc, lport->state, disc->pending);
158 }
159 fc_frame_free(fp);
160 return;
161 reject:
162 FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
163 rjt_data.reason = ELS_RJT_LOGIC;
164 rjt_data.explan = ELS_EXPL_NONE;
165 fc_seq_els_rsp_send(fp, ELS_LS_RJT, &rjt_data);
166 fc_frame_free(fp);
167 }
168
169 /**
170 * fc_disc_recv_req() - Handle incoming requests
171 * @lport: The local port receiving the request
172 * @fp: The request frame
173 *
174 * Locking Note: This function is called from the EM and will lock
175 * the disc_mutex before calling the handler for the
176 * request.
177 */
fc_disc_recv_req(struct fc_lport * lport,struct fc_frame * fp)178 static void fc_disc_recv_req(struct fc_lport *lport, struct fc_frame *fp)
179 {
180 u8 op;
181 struct fc_disc *disc = &lport->disc;
182
183 op = fc_frame_payload_op(fp);
184 switch (op) {
185 case ELS_RSCN:
186 mutex_lock(&disc->disc_mutex);
187 fc_disc_recv_rscn_req(disc, fp);
188 mutex_unlock(&disc->disc_mutex);
189 break;
190 default:
191 FC_DISC_DBG(disc, "Received an unsupported request, "
192 "the opcode is (%x)\n", op);
193 fc_frame_free(fp);
194 break;
195 }
196 }
197
198 /**
199 * fc_disc_restart() - Restart discovery
200 * @disc: The discovery object to be restarted
201 */
fc_disc_restart(struct fc_disc * disc)202 static void fc_disc_restart(struct fc_disc *disc)
203 {
204 lockdep_assert_held(&disc->disc_mutex);
205
206 if (!disc->disc_callback)
207 return;
208
209 FC_DISC_DBG(disc, "Restarting discovery\n");
210
211 disc->requested = 1;
212 if (disc->pending)
213 return;
214
215 /*
216 * Advance disc_id. This is an arbitrary non-zero number that will
217 * match the value in the fc_rport_priv after discovery for all
218 * freshly-discovered remote ports. Avoid wrapping to zero.
219 */
220 disc->disc_id = (disc->disc_id + 2) | 1;
221 disc->retry_count = 0;
222 fc_disc_gpn_ft_req(disc);
223 }
224
225 /**
226 * fc_disc_start() - Start discovery on a local port
227 * @lport: The local port to have discovery started on
228 * @disc_callback: Callback function to be called when discovery is complete
229 */
fc_disc_start(void (* disc_callback)(struct fc_lport *,enum fc_disc_event),struct fc_lport * lport)230 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
231 enum fc_disc_event),
232 struct fc_lport *lport)
233 {
234 struct fc_disc *disc = &lport->disc;
235
236 /*
237 * At this point we may have a new disc job or an existing
238 * one. Either way, let's lock when we make changes to it
239 * and send the GPN_FT request.
240 */
241 mutex_lock(&disc->disc_mutex);
242 disc->disc_callback = disc_callback;
243 fc_disc_restart(disc);
244 mutex_unlock(&disc->disc_mutex);
245 }
246
247 /**
248 * fc_disc_done() - Discovery has been completed
249 * @disc: The discovery context
250 * @event: The discovery completion status
251 */
fc_disc_done(struct fc_disc * disc,enum fc_disc_event event)252 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
253 {
254 struct fc_lport *lport = fc_disc_lport(disc);
255 struct fc_rport_priv *rdata;
256
257 lockdep_assert_held(&disc->disc_mutex);
258 FC_DISC_DBG(disc, "Discovery complete\n");
259
260 disc->pending = 0;
261 if (disc->requested) {
262 fc_disc_restart(disc);
263 return;
264 }
265
266 /*
267 * Go through all remote ports. If they were found in the latest
268 * discovery, reverify or log them in. Otherwise, log them out.
269 * Skip ports which were never discovered. These are the dNS port
270 * and ports which were created by PLOGI.
271 *
272 * We don't need to use the _rcu variant here as the rport list
273 * is protected by the disc mutex which is already held on entry.
274 */
275 list_for_each_entry(rdata, &disc->rports, peers) {
276 if (!kref_get_unless_zero(&rdata->kref))
277 continue;
278 if (rdata->disc_id) {
279 if (rdata->disc_id == disc->disc_id)
280 fc_rport_login(rdata);
281 else
282 fc_rport_logoff(rdata);
283 }
284 kref_put(&rdata->kref, fc_rport_destroy);
285 }
286 mutex_unlock(&disc->disc_mutex);
287 disc->disc_callback(lport, event);
288 mutex_lock(&disc->disc_mutex);
289 }
290
291 /**
292 * fc_disc_error() - Handle error on dNS request
293 * @disc: The discovery context
294 * @fp: The error code encoded as a frame pointer
295 */
fc_disc_error(struct fc_disc * disc,struct fc_frame * fp)296 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
297 {
298 struct fc_lport *lport = fc_disc_lport(disc);
299 unsigned long delay = 0;
300
301 FC_DISC_DBG(disc, "Error %d, retries %d/%d\n",
302 PTR_ERR_OR_ZERO(fp), disc->retry_count,
303 FC_DISC_RETRY_LIMIT);
304
305 if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
306 /*
307 * Memory allocation failure, or the exchange timed out,
308 * retry after delay.
309 */
310 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
311 /* go ahead and retry */
312 if (!fp)
313 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
314 else {
315 delay = msecs_to_jiffies(lport->e_d_tov);
316
317 /* timeout faster first time */
318 if (!disc->retry_count)
319 delay /= 4;
320 }
321 disc->retry_count++;
322 schedule_delayed_work(&disc->disc_work, delay);
323 } else
324 fc_disc_done(disc, DISC_EV_FAILED);
325 } else if (PTR_ERR(fp) == -FC_EX_CLOSED) {
326 /*
327 * if discovery fails due to lport reset, clear
328 * pending flag so that subsequent discovery can
329 * continue
330 */
331 disc->pending = 0;
332 }
333 }
334
335 /**
336 * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
337 * @disc: The discovery context
338 */
fc_disc_gpn_ft_req(struct fc_disc * disc)339 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
340 {
341 struct fc_frame *fp;
342 struct fc_lport *lport = fc_disc_lport(disc);
343
344 lockdep_assert_held(&disc->disc_mutex);
345
346 WARN_ON(!fc_lport_test_ready(lport));
347
348 disc->pending = 1;
349 disc->requested = 0;
350
351 disc->buf_len = 0;
352 disc->seq_count = 0;
353 fp = fc_frame_alloc(lport,
354 sizeof(struct fc_ct_hdr) +
355 sizeof(struct fc_ns_gid_ft));
356 if (!fp)
357 goto err;
358
359 if (lport->tt.elsct_send(lport, 0, fp,
360 FC_NS_GPN_FT,
361 fc_disc_gpn_ft_resp,
362 disc, 3 * lport->r_a_tov))
363 return;
364 err:
365 fc_disc_error(disc, NULL);
366 }
367
368 /**
369 * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
370 * @disc: The discovery context
371 * @buf: The GPN_FT response buffer
372 * @len: The size of response buffer
373 *
374 * Goes through the list of IDs and names resulting from a request.
375 */
fc_disc_gpn_ft_parse(struct fc_disc * disc,void * buf,size_t len)376 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
377 {
378 struct fc_lport *lport;
379 struct fc_gpn_ft_resp *np;
380 char *bp;
381 size_t plen;
382 size_t tlen;
383 int error = 0;
384 struct fc_rport_identifiers ids;
385 struct fc_rport_priv *rdata;
386
387 lport = fc_disc_lport(disc);
388 disc->seq_count++;
389
390 /*
391 * Handle partial name record left over from previous call.
392 */
393 bp = buf;
394 plen = len;
395 np = (struct fc_gpn_ft_resp *)bp;
396 tlen = disc->buf_len;
397 disc->buf_len = 0;
398 if (tlen) {
399 WARN_ON(tlen >= sizeof(*np));
400 plen = sizeof(*np) - tlen;
401 WARN_ON(plen <= 0);
402 WARN_ON(plen >= sizeof(*np));
403 if (plen > len)
404 plen = len;
405 np = &disc->partial_buf;
406 memcpy((char *)np + tlen, bp, plen);
407
408 /*
409 * Set bp so that the loop below will advance it to the
410 * first valid full name element.
411 */
412 bp -= tlen;
413 len += tlen;
414 plen += tlen;
415 disc->buf_len = (unsigned char) plen;
416 if (plen == sizeof(*np))
417 disc->buf_len = 0;
418 }
419
420 /*
421 * Handle full name records, including the one filled from above.
422 * Normally, np == bp and plen == len, but from the partial case above,
423 * bp, len describe the overall buffer, and np, plen describe the
424 * partial buffer, which if would usually be full now.
425 * After the first time through the loop, things return to "normal".
426 */
427 while (plen >= sizeof(*np)) {
428 ids.port_id = ntoh24(np->fp_fid);
429 ids.port_name = ntohll(np->fp_wwpn);
430
431 if (ids.port_id != lport->port_id &&
432 ids.port_name != lport->wwpn) {
433 rdata = fc_rport_create(lport, ids.port_id);
434 if (rdata) {
435 rdata->ids.port_name = ids.port_name;
436 rdata->disc_id = disc->disc_id;
437 } else {
438 printk(KERN_WARNING "libfc: Failed to allocate "
439 "memory for the newly discovered port "
440 "(%6.6x)\n", ids.port_id);
441 error = -ENOMEM;
442 }
443 }
444
445 if (np->fp_flags & FC_NS_FID_LAST) {
446 fc_disc_done(disc, DISC_EV_SUCCESS);
447 len = 0;
448 break;
449 }
450 len -= sizeof(*np);
451 bp += sizeof(*np);
452 np = (struct fc_gpn_ft_resp *)bp;
453 plen = len;
454 }
455
456 /*
457 * Save any partial record at the end of the buffer for next time.
458 */
459 if (error == 0 && len > 0 && len < sizeof(*np)) {
460 if (np != &disc->partial_buf) {
461 FC_DISC_DBG(disc, "Partial buffer remains "
462 "for discovery\n");
463 memcpy(&disc->partial_buf, np, len);
464 }
465 disc->buf_len = (unsigned char) len;
466 }
467 return error;
468 }
469
470 /**
471 * fc_disc_timeout() - Handler for discovery timeouts
472 * @work: Structure holding discovery context that needs to retry discovery
473 */
fc_disc_timeout(struct work_struct * work)474 static void fc_disc_timeout(struct work_struct *work)
475 {
476 struct fc_disc *disc = container_of(work,
477 struct fc_disc,
478 disc_work.work);
479 mutex_lock(&disc->disc_mutex);
480 fc_disc_gpn_ft_req(disc);
481 mutex_unlock(&disc->disc_mutex);
482 }
483
484 /**
485 * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
486 * @sp: The sequence that the GPN_FT response was received on
487 * @fp: The GPN_FT response frame
488 * @disc_arg: The discovery context
489 *
490 * Locking Note: This function is called without disc mutex held, and
491 * should do all its processing with the mutex held
492 */
fc_disc_gpn_ft_resp(struct fc_seq * sp,struct fc_frame * fp,void * disc_arg)493 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
494 void *disc_arg)
495 {
496 struct fc_disc *disc = disc_arg;
497 struct fc_ct_hdr *cp;
498 struct fc_frame_header *fh;
499 enum fc_disc_event event = DISC_EV_NONE;
500 unsigned int seq_cnt;
501 unsigned int len;
502 int error = 0;
503
504 mutex_lock(&disc->disc_mutex);
505 FC_DISC_DBG(disc, "Received a GPN_FT response\n");
506
507 if (IS_ERR(fp)) {
508 fc_disc_error(disc, fp);
509 mutex_unlock(&disc->disc_mutex);
510 return;
511 }
512
513 WARN_ON(!fc_frame_is_linear(fp)); /* buffer must be contiguous */
514 fh = fc_frame_header_get(fp);
515 len = fr_len(fp) - sizeof(*fh);
516 seq_cnt = ntohs(fh->fh_seq_cnt);
517 if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
518 cp = fc_frame_payload_get(fp, sizeof(*cp));
519 if (!cp) {
520 FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
521 fr_len(fp));
522 event = DISC_EV_FAILED;
523 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
524
525 /* Accepted, parse the response. */
526 len -= sizeof(*cp);
527 error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
528 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
529 FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
530 "(check zoning)\n", cp->ct_reason,
531 cp->ct_explan);
532 event = DISC_EV_FAILED;
533 if (cp->ct_reason == FC_FS_RJT_UNABL &&
534 cp->ct_explan == FC_FS_EXP_FTNR)
535 event = DISC_EV_SUCCESS;
536 } else {
537 FC_DISC_DBG(disc, "GPN_FT unexpected response code "
538 "%x\n", ntohs(cp->ct_cmd));
539 event = DISC_EV_FAILED;
540 }
541 } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
542 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
543 } else {
544 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
545 "seq_cnt %x expected %x sof %x eof %x\n",
546 seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
547 event = DISC_EV_FAILED;
548 }
549 if (error)
550 fc_disc_error(disc, ERR_PTR(error));
551 else if (event != DISC_EV_NONE)
552 fc_disc_done(disc, event);
553 fc_frame_free(fp);
554 mutex_unlock(&disc->disc_mutex);
555 }
556
557 /**
558 * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
559 * @sp: The sequence the GPN_ID is on
560 * @fp: The response frame
561 * @rdata_arg: The remote port that sent the GPN_ID response
562 *
563 * Locking Note: This function is called without disc mutex held.
564 */
fc_disc_gpn_id_resp(struct fc_seq * sp,struct fc_frame * fp,void * rdata_arg)565 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
566 void *rdata_arg)
567 {
568 struct fc_rport_priv *rdata = rdata_arg;
569 struct fc_rport_priv *new_rdata;
570 struct fc_lport *lport;
571 struct fc_disc *disc;
572 struct fc_ct_hdr *cp;
573 struct fc_ns_gid_pn *pn;
574 u64 port_name;
575
576 lport = rdata->local_port;
577 disc = &lport->disc;
578
579 if (PTR_ERR(fp) == -FC_EX_CLOSED)
580 goto out;
581 if (IS_ERR(fp)) {
582 mutex_lock(&disc->disc_mutex);
583 fc_disc_restart(disc);
584 mutex_unlock(&disc->disc_mutex);
585 goto out;
586 }
587
588 cp = fc_frame_payload_get(fp, sizeof(*cp));
589 if (!cp)
590 goto redisc;
591 if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
592 if (fr_len(fp) < sizeof(struct fc_frame_header) +
593 sizeof(*cp) + sizeof(*pn))
594 goto redisc;
595 pn = (struct fc_ns_gid_pn *)(cp + 1);
596 port_name = get_unaligned_be64(&pn->fn_wwpn);
597 mutex_lock(&rdata->rp_mutex);
598 if (rdata->ids.port_name == -1)
599 rdata->ids.port_name = port_name;
600 else if (rdata->ids.port_name != port_name) {
601 FC_DISC_DBG(disc, "GPN_ID accepted. WWPN changed. "
602 "Port-id %6.6x wwpn %16.16llx\n",
603 rdata->ids.port_id, port_name);
604 mutex_unlock(&rdata->rp_mutex);
605 fc_rport_logoff(rdata);
606 mutex_lock(&lport->disc.disc_mutex);
607 new_rdata = fc_rport_create(lport, rdata->ids.port_id);
608 mutex_unlock(&lport->disc.disc_mutex);
609 if (new_rdata) {
610 new_rdata->disc_id = disc->disc_id;
611 fc_rport_login(new_rdata);
612 }
613 goto free_fp;
614 }
615 rdata->disc_id = disc->disc_id;
616 mutex_unlock(&rdata->rp_mutex);
617 fc_rport_login(rdata);
618 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
619 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
620 cp->ct_reason, cp->ct_explan);
621 fc_rport_logoff(rdata);
622 } else {
623 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
624 ntohs(cp->ct_cmd));
625 redisc:
626 mutex_lock(&disc->disc_mutex);
627 fc_disc_restart(disc);
628 mutex_unlock(&disc->disc_mutex);
629 }
630 free_fp:
631 fc_frame_free(fp);
632 out:
633 kref_put(&rdata->kref, fc_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 * On failure, an error code is returned.
642 */
fc_disc_gpn_id_req(struct fc_lport * lport,struct fc_rport_priv * rdata)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 lockdep_assert_held(&lport->disc.disc_mutex);
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 */
fc_disc_single(struct fc_lport * lport,struct fc_disc_port * dp)666 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
667 {
668 struct fc_rport_priv *rdata;
669
670 lockdep_assert_held(&lport->disc.disc_mutex);
671
672 rdata = fc_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 */
fc_disc_stop(struct fc_lport * lport)683 static void fc_disc_stop(struct fc_lport *lport)
684 {
685 struct fc_disc *disc = &lport->disc;
686
687 if (disc->pending)
688 cancel_delayed_work_sync(&disc->disc_work);
689 mutex_lock(&disc->disc_mutex);
690 fc_disc_stop_rports(disc);
691 mutex_unlock(&disc->disc_mutex);
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 */
fc_disc_stop_final(struct fc_lport * lport)701 static void fc_disc_stop_final(struct fc_lport *lport)
702 {
703 fc_disc_stop(lport);
704 fc_rport_flush_queue();
705 }
706
707 /**
708 * fc_disc_config() - Configure the discovery layer for a local port
709 * @lport: The local port that needs the discovery layer to be configured
710 * @priv: Private data structre for users of the discovery layer
711 */
fc_disc_config(struct fc_lport * lport,void * priv)712 void fc_disc_config(struct fc_lport *lport, void *priv)
713 {
714 struct fc_disc *disc;
715
716 if (!lport->tt.disc_start)
717 lport->tt.disc_start = fc_disc_start;
718
719 if (!lport->tt.disc_stop)
720 lport->tt.disc_stop = fc_disc_stop;
721
722 if (!lport->tt.disc_stop_final)
723 lport->tt.disc_stop_final = fc_disc_stop_final;
724
725 if (!lport->tt.disc_recv_req)
726 lport->tt.disc_recv_req = fc_disc_recv_req;
727
728 disc = &lport->disc;
729
730 disc->priv = priv;
731 }
732 EXPORT_SYMBOL(fc_disc_config);
733
734 /**
735 * fc_disc_init() - Initialize the discovery layer for a local port
736 * @lport: The local port that needs the discovery layer to be initialized
737 */
fc_disc_init(struct fc_lport * lport)738 void fc_disc_init(struct fc_lport *lport)
739 {
740 struct fc_disc *disc = &lport->disc;
741
742 INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
743 mutex_init(&disc->disc_mutex);
744 INIT_LIST_HEAD(&disc->rports);
745 }
746 EXPORT_SYMBOL(fc_disc_init);
747