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
50static void fc_disc_gpn_ft_req(struct fc_disc *);
51static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
52static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
53static void fc_disc_timeout(struct work_struct *);
54static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
55static 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 */
64static 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 */
85static 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;
177reject:
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 */
194static 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 */
221static 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 */
247static 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 */
273static 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 */
311static 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 * Locking Note: This function expects that the disc_mutex is locked
355 *		 before it is called.
356 */
357static void fc_disc_gpn_ft_req(struct fc_disc *disc)
358{
359	struct fc_frame *fp;
360	struct fc_lport *lport = fc_disc_lport(disc);
361
362	WARN_ON(!fc_lport_test_ready(lport));
363
364	disc->pending = 1;
365	disc->requested = 0;
366
367	disc->buf_len = 0;
368	disc->seq_count = 0;
369	fp = fc_frame_alloc(lport,
370			    sizeof(struct fc_ct_hdr) +
371			    sizeof(struct fc_ns_gid_ft));
372	if (!fp)
373		goto err;
374
375	if (lport->tt.elsct_send(lport, 0, fp,
376				 FC_NS_GPN_FT,
377				 fc_disc_gpn_ft_resp,
378				 disc, 3 * lport->r_a_tov))
379		return;
380err:
381	fc_disc_error(disc, NULL);
382}
383
384/**
385 * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
386 * @lport: The local port the GPN_FT was received on
387 * @buf:   The GPN_FT response buffer
388 * @len:   The size of response buffer
389 *
390 * Goes through the list of IDs and names resulting from a request.
391 */
392static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
393{
394	struct fc_lport *lport;
395	struct fc_gpn_ft_resp *np;
396	char *bp;
397	size_t plen;
398	size_t tlen;
399	int error = 0;
400	struct fc_rport_identifiers ids;
401	struct fc_rport_priv *rdata;
402
403	lport = fc_disc_lport(disc);
404	disc->seq_count++;
405
406	/*
407	 * Handle partial name record left over from previous call.
408	 */
409	bp = buf;
410	plen = len;
411	np = (struct fc_gpn_ft_resp *)bp;
412	tlen = disc->buf_len;
413	disc->buf_len = 0;
414	if (tlen) {
415		WARN_ON(tlen >= sizeof(*np));
416		plen = sizeof(*np) - tlen;
417		WARN_ON(plen <= 0);
418		WARN_ON(plen >= sizeof(*np));
419		if (plen > len)
420			plen = len;
421		np = &disc->partial_buf;
422		memcpy((char *)np + tlen, bp, plen);
423
424		/*
425		 * Set bp so that the loop below will advance it to the
426		 * first valid full name element.
427		 */
428		bp -= tlen;
429		len += tlen;
430		plen += tlen;
431		disc->buf_len = (unsigned char) plen;
432		if (plen == sizeof(*np))
433			disc->buf_len = 0;
434	}
435
436	/*
437	 * Handle full name records, including the one filled from above.
438	 * Normally, np == bp and plen == len, but from the partial case above,
439	 * bp, len describe the overall buffer, and np, plen describe the
440	 * partial buffer, which if would usually be full now.
441	 * After the first time through the loop, things return to "normal".
442	 */
443	while (plen >= sizeof(*np)) {
444		ids.port_id = ntoh24(np->fp_fid);
445		ids.port_name = ntohll(np->fp_wwpn);
446
447		if (ids.port_id != lport->port_id &&
448		    ids.port_name != lport->wwpn) {
449			rdata = lport->tt.rport_create(lport, ids.port_id);
450			if (rdata) {
451				rdata->ids.port_name = ids.port_name;
452				rdata->disc_id = disc->disc_id;
453			} else {
454				printk(KERN_WARNING "libfc: Failed to allocate "
455				       "memory for the newly discovered port "
456				       "(%6.6x)\n", ids.port_id);
457				error = -ENOMEM;
458			}
459		}
460
461		if (np->fp_flags & FC_NS_FID_LAST) {
462			fc_disc_done(disc, DISC_EV_SUCCESS);
463			len = 0;
464			break;
465		}
466		len -= sizeof(*np);
467		bp += sizeof(*np);
468		np = (struct fc_gpn_ft_resp *)bp;
469		plen = len;
470	}
471
472	/*
473	 * Save any partial record at the end of the buffer for next time.
474	 */
475	if (error == 0 && len > 0 && len < sizeof(*np)) {
476		if (np != &disc->partial_buf) {
477			FC_DISC_DBG(disc, "Partial buffer remains "
478				    "for discovery\n");
479			memcpy(&disc->partial_buf, np, len);
480		}
481		disc->buf_len = (unsigned char) len;
482	}
483	return error;
484}
485
486/**
487 * fc_disc_timeout() - Handler for discovery timeouts
488 * @work: Structure holding discovery context that needs to retry discovery
489 */
490static void fc_disc_timeout(struct work_struct *work)
491{
492	struct fc_disc *disc = container_of(work,
493					    struct fc_disc,
494					    disc_work.work);
495	mutex_lock(&disc->disc_mutex);
496	fc_disc_gpn_ft_req(disc);
497	mutex_unlock(&disc->disc_mutex);
498}
499
500/**
501 * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
502 * @sp:	    The sequence that the GPN_FT response was received on
503 * @fp:	    The GPN_FT response frame
504 * @lp_arg: The discovery context
505 *
506 * Locking Note: This function is called without disc mutex held, and
507 *		 should do all its processing with the mutex held
508 */
509static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
510				void *disc_arg)
511{
512	struct fc_disc *disc = disc_arg;
513	struct fc_ct_hdr *cp;
514	struct fc_frame_header *fh;
515	enum fc_disc_event event = DISC_EV_NONE;
516	unsigned int seq_cnt;
517	unsigned int len;
518	int error = 0;
519
520	mutex_lock(&disc->disc_mutex);
521	FC_DISC_DBG(disc, "Received a GPN_FT response\n");
522
523	if (IS_ERR(fp)) {
524		fc_disc_error(disc, fp);
525		mutex_unlock(&disc->disc_mutex);
526		return;
527	}
528
529	WARN_ON(!fc_frame_is_linear(fp));	/* buffer must be contiguous */
530	fh = fc_frame_header_get(fp);
531	len = fr_len(fp) - sizeof(*fh);
532	seq_cnt = ntohs(fh->fh_seq_cnt);
533	if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
534		cp = fc_frame_payload_get(fp, sizeof(*cp));
535		if (!cp) {
536			FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
537				    fr_len(fp));
538			event = DISC_EV_FAILED;
539		} else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
540
541			/* Accepted, parse the response. */
542			len -= sizeof(*cp);
543			error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
544		} else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
545			FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
546				    "(check zoning)\n", cp->ct_reason,
547				    cp->ct_explan);
548			event = DISC_EV_FAILED;
549			if (cp->ct_reason == FC_FS_RJT_UNABL &&
550			    cp->ct_explan == FC_FS_EXP_FTNR)
551				event = DISC_EV_SUCCESS;
552		} else {
553			FC_DISC_DBG(disc, "GPN_FT unexpected response code "
554				    "%x\n", ntohs(cp->ct_cmd));
555			event = DISC_EV_FAILED;
556		}
557	} else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
558		error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
559	} else {
560		FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
561			    "seq_cnt %x expected %x sof %x eof %x\n",
562			    seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
563		event = DISC_EV_FAILED;
564	}
565	if (error)
566		fc_disc_error(disc, fp);
567	else if (event != DISC_EV_NONE)
568		fc_disc_done(disc, event);
569	fc_frame_free(fp);
570	mutex_unlock(&disc->disc_mutex);
571}
572
573/**
574 * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
575 * @sp:	       The sequence the GPN_ID is on
576 * @fp:	       The response frame
577 * @rdata_arg: The remote port that sent the GPN_ID response
578 *
579 * Locking Note: This function is called without disc mutex held.
580 */
581static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
582				void *rdata_arg)
583{
584	struct fc_rport_priv *rdata = rdata_arg;
585	struct fc_rport_priv *new_rdata;
586	struct fc_lport *lport;
587	struct fc_disc *disc;
588	struct fc_ct_hdr *cp;
589	struct fc_ns_gid_pn *pn;
590	u64 port_name;
591
592	lport = rdata->local_port;
593	disc = &lport->disc;
594
595	mutex_lock(&disc->disc_mutex);
596	if (PTR_ERR(fp) == -FC_EX_CLOSED)
597		goto out;
598	if (IS_ERR(fp))
599		goto redisc;
600
601	cp = fc_frame_payload_get(fp, sizeof(*cp));
602	if (!cp)
603		goto redisc;
604	if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
605		if (fr_len(fp) < sizeof(struct fc_frame_header) +
606		    sizeof(*cp) + sizeof(*pn))
607			goto redisc;
608		pn = (struct fc_ns_gid_pn *)(cp + 1);
609		port_name = get_unaligned_be64(&pn->fn_wwpn);
610		if (rdata->ids.port_name == -1)
611			rdata->ids.port_name = port_name;
612		else if (rdata->ids.port_name != port_name) {
613			FC_DISC_DBG(disc, "GPN_ID accepted.  WWPN changed. "
614				    "Port-id %6.6x wwpn %16.16llx\n",
615				    rdata->ids.port_id, port_name);
616			lport->tt.rport_logoff(rdata);
617
618			new_rdata = lport->tt.rport_create(lport,
619							   rdata->ids.port_id);
620			if (new_rdata) {
621				new_rdata->disc_id = disc->disc_id;
622				lport->tt.rport_login(new_rdata);
623			}
624			goto out;
625		}
626		rdata->disc_id = disc->disc_id;
627		lport->tt.rport_login(rdata);
628	} else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
629		FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
630			    cp->ct_reason, cp->ct_explan);
631		lport->tt.rport_logoff(rdata);
632	} else {
633		FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
634			    ntohs(cp->ct_cmd));
635redisc:
636		fc_disc_restart(disc);
637	}
638out:
639	mutex_unlock(&disc->disc_mutex);
640	kref_put(&rdata->kref, lport->tt.rport_destroy);
641}
642
643/**
644 * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
645 * @lport: The local port to initiate discovery on
646 * @rdata: remote port private data
647 *
648 * Locking Note: This function expects that the disc_mutex is locked
649 *		 before it is called.
650 * On failure, an error code is returned.
651 */
652static int fc_disc_gpn_id_req(struct fc_lport *lport,
653			      struct fc_rport_priv *rdata)
654{
655	struct fc_frame *fp;
656
657	fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
658			    sizeof(struct fc_ns_fid));
659	if (!fp)
660		return -ENOMEM;
661	if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
662				  fc_disc_gpn_id_resp, rdata,
663				  3 * lport->r_a_tov))
664		return -ENOMEM;
665	kref_get(&rdata->kref);
666	return 0;
667}
668
669/**
670 * fc_disc_single() - Discover the directory information for a single target
671 * @lport: The local port the remote port is associated with
672 * @dp:	   The port to rediscover
673 *
674 * Locking Note: This function expects that the disc_mutex is locked
675 *		 before it is called.
676 */
677static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
678{
679	struct fc_rport_priv *rdata;
680
681	rdata = lport->tt.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 */
692static 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	fc_disc_stop_rports(disc);
699}
700
701/**
702 * fc_disc_stop_final() - Stop discovery for a given lport
703 * @lport: The lport that discovery should stop on
704 *
705 * This function will block until discovery has been
706 * completely stopped and all rports have been deleted.
707 */
708static void fc_disc_stop_final(struct fc_lport *lport)
709{
710	fc_disc_stop(lport);
711	lport->tt.rport_flush_queue();
712}
713
714/**
715 * fc_disc_config() - Configure the discovery layer for a local port
716 * @lport: The local port that needs the discovery layer to be configured
717 * @priv: Private data structre for users of the discovery layer
718 */
719void fc_disc_config(struct fc_lport *lport, void *priv)
720{
721	struct fc_disc *disc = &lport->disc;
722
723	if (!lport->tt.disc_start)
724		lport->tt.disc_start = fc_disc_start;
725
726	if (!lport->tt.disc_stop)
727		lport->tt.disc_stop = fc_disc_stop;
728
729	if (!lport->tt.disc_stop_final)
730		lport->tt.disc_stop_final = fc_disc_stop_final;
731
732	if (!lport->tt.disc_recv_req)
733		lport->tt.disc_recv_req = fc_disc_recv_req;
734
735	disc = &lport->disc;
736
737	disc->priv = priv;
738}
739EXPORT_SYMBOL(fc_disc_config);
740
741/**
742 * fc_disc_init() - Initialize the discovery layer for a local port
743 * @lport: The local port that needs the discovery layer to be initialized
744 */
745void fc_disc_init(struct fc_lport *lport)
746{
747	struct fc_disc *disc = &lport->disc;
748
749	INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
750	mutex_init(&disc->disc_mutex);
751	INIT_LIST_HEAD(&disc->rports);
752}
753EXPORT_SYMBOL(fc_disc_init);
754