xref: /openbmc/linux/net/ceph/mon_client.c (revision 6aa7de05)
1 #include <linux/ceph/ceph_debug.h>
2 
3 #include <linux/module.h>
4 #include <linux/types.h>
5 #include <linux/slab.h>
6 #include <linux/random.h>
7 #include <linux/sched.h>
8 
9 #include <linux/ceph/ceph_features.h>
10 #include <linux/ceph/mon_client.h>
11 #include <linux/ceph/libceph.h>
12 #include <linux/ceph/debugfs.h>
13 #include <linux/ceph/decode.h>
14 #include <linux/ceph/auth.h>
15 
16 /*
17  * Interact with Ceph monitor cluster.  Handle requests for new map
18  * versions, and periodically resend as needed.  Also implement
19  * statfs() and umount().
20  *
21  * A small cluster of Ceph "monitors" are responsible for managing critical
22  * cluster configuration and state information.  An odd number (e.g., 3, 5)
23  * of cmon daemons use a modified version of the Paxos part-time parliament
24  * algorithm to manage the MDS map (mds cluster membership), OSD map, and
25  * list of clients who have mounted the file system.
26  *
27  * We maintain an open, active session with a monitor at all times in order to
28  * receive timely MDSMap updates.  We periodically send a keepalive byte on the
29  * TCP socket to ensure we detect a failure.  If the connection does break, we
30  * randomly hunt for a new monitor.  Once the connection is reestablished, we
31  * resend any outstanding requests.
32  */
33 
34 static const struct ceph_connection_operations mon_con_ops;
35 
36 static int __validate_auth(struct ceph_mon_client *monc);
37 
38 /*
39  * Decode a monmap blob (e.g., during mount).
40  */
41 struct ceph_monmap *ceph_monmap_decode(void *p, void *end)
42 {
43 	struct ceph_monmap *m = NULL;
44 	int i, err = -EINVAL;
45 	struct ceph_fsid fsid;
46 	u32 epoch, num_mon;
47 	u32 len;
48 
49 	ceph_decode_32_safe(&p, end, len, bad);
50 	ceph_decode_need(&p, end, len, bad);
51 
52 	dout("monmap_decode %p %p len %d\n", p, end, (int)(end-p));
53 	p += sizeof(u16);  /* skip version */
54 
55 	ceph_decode_need(&p, end, sizeof(fsid) + 2*sizeof(u32), bad);
56 	ceph_decode_copy(&p, &fsid, sizeof(fsid));
57 	epoch = ceph_decode_32(&p);
58 
59 	num_mon = ceph_decode_32(&p);
60 	ceph_decode_need(&p, end, num_mon*sizeof(m->mon_inst[0]), bad);
61 
62 	if (num_mon >= CEPH_MAX_MON)
63 		goto bad;
64 	m = kmalloc(sizeof(*m) + sizeof(m->mon_inst[0])*num_mon, GFP_NOFS);
65 	if (m == NULL)
66 		return ERR_PTR(-ENOMEM);
67 	m->fsid = fsid;
68 	m->epoch = epoch;
69 	m->num_mon = num_mon;
70 	ceph_decode_copy(&p, m->mon_inst, num_mon*sizeof(m->mon_inst[0]));
71 	for (i = 0; i < num_mon; i++)
72 		ceph_decode_addr(&m->mon_inst[i].addr);
73 
74 	dout("monmap_decode epoch %d, num_mon %d\n", m->epoch,
75 	     m->num_mon);
76 	for (i = 0; i < m->num_mon; i++)
77 		dout("monmap_decode  mon%d is %s\n", i,
78 		     ceph_pr_addr(&m->mon_inst[i].addr.in_addr));
79 	return m;
80 
81 bad:
82 	dout("monmap_decode failed with %d\n", err);
83 	kfree(m);
84 	return ERR_PTR(err);
85 }
86 
87 /*
88  * return true if *addr is included in the monmap.
89  */
90 int ceph_monmap_contains(struct ceph_monmap *m, struct ceph_entity_addr *addr)
91 {
92 	int i;
93 
94 	for (i = 0; i < m->num_mon; i++)
95 		if (memcmp(addr, &m->mon_inst[i].addr, sizeof(*addr)) == 0)
96 			return 1;
97 	return 0;
98 }
99 
100 /*
101  * Send an auth request.
102  */
103 static void __send_prepared_auth_request(struct ceph_mon_client *monc, int len)
104 {
105 	monc->pending_auth = 1;
106 	monc->m_auth->front.iov_len = len;
107 	monc->m_auth->hdr.front_len = cpu_to_le32(len);
108 	ceph_msg_revoke(monc->m_auth);
109 	ceph_msg_get(monc->m_auth);  /* keep our ref */
110 	ceph_con_send(&monc->con, monc->m_auth);
111 }
112 
113 /*
114  * Close monitor session, if any.
115  */
116 static void __close_session(struct ceph_mon_client *monc)
117 {
118 	dout("__close_session closing mon%d\n", monc->cur_mon);
119 	ceph_msg_revoke(monc->m_auth);
120 	ceph_msg_revoke_incoming(monc->m_auth_reply);
121 	ceph_msg_revoke(monc->m_subscribe);
122 	ceph_msg_revoke_incoming(monc->m_subscribe_ack);
123 	ceph_con_close(&monc->con);
124 
125 	monc->pending_auth = 0;
126 	ceph_auth_reset(monc->auth);
127 }
128 
129 /*
130  * Pick a new monitor at random and set cur_mon.  If we are repicking
131  * (i.e. cur_mon is already set), be sure to pick a different one.
132  */
133 static void pick_new_mon(struct ceph_mon_client *monc)
134 {
135 	int old_mon = monc->cur_mon;
136 
137 	BUG_ON(monc->monmap->num_mon < 1);
138 
139 	if (monc->monmap->num_mon == 1) {
140 		monc->cur_mon = 0;
141 	} else {
142 		int max = monc->monmap->num_mon;
143 		int o = -1;
144 		int n;
145 
146 		if (monc->cur_mon >= 0) {
147 			if (monc->cur_mon < monc->monmap->num_mon)
148 				o = monc->cur_mon;
149 			if (o >= 0)
150 				max--;
151 		}
152 
153 		n = prandom_u32() % max;
154 		if (o >= 0 && n >= o)
155 			n++;
156 
157 		monc->cur_mon = n;
158 	}
159 
160 	dout("%s mon%d -> mon%d out of %d mons\n", __func__, old_mon,
161 	     monc->cur_mon, monc->monmap->num_mon);
162 }
163 
164 /*
165  * Open a session with a new monitor.
166  */
167 static void __open_session(struct ceph_mon_client *monc)
168 {
169 	int ret;
170 
171 	pick_new_mon(monc);
172 
173 	monc->hunting = true;
174 	if (monc->had_a_connection) {
175 		monc->hunt_mult *= CEPH_MONC_HUNT_BACKOFF;
176 		if (monc->hunt_mult > CEPH_MONC_HUNT_MAX_MULT)
177 			monc->hunt_mult = CEPH_MONC_HUNT_MAX_MULT;
178 	}
179 
180 	monc->sub_renew_after = jiffies; /* i.e., expired */
181 	monc->sub_renew_sent = 0;
182 
183 	dout("%s opening mon%d\n", __func__, monc->cur_mon);
184 	ceph_con_open(&monc->con, CEPH_ENTITY_TYPE_MON, monc->cur_mon,
185 		      &monc->monmap->mon_inst[monc->cur_mon].addr);
186 
187 	/*
188 	 * send an initial keepalive to ensure our timestamp is valid
189 	 * by the time we are in an OPENED state
190 	 */
191 	ceph_con_keepalive(&monc->con);
192 
193 	/* initiate authentication handshake */
194 	ret = ceph_auth_build_hello(monc->auth,
195 				    monc->m_auth->front.iov_base,
196 				    monc->m_auth->front_alloc_len);
197 	BUG_ON(ret <= 0);
198 	__send_prepared_auth_request(monc, ret);
199 }
200 
201 static void reopen_session(struct ceph_mon_client *monc)
202 {
203 	if (!monc->hunting)
204 		pr_info("mon%d %s session lost, hunting for new mon\n",
205 		    monc->cur_mon, ceph_pr_addr(&monc->con.peer_addr.in_addr));
206 
207 	__close_session(monc);
208 	__open_session(monc);
209 }
210 
211 /*
212  * Reschedule delayed work timer.
213  */
214 static void __schedule_delayed(struct ceph_mon_client *monc)
215 {
216 	unsigned long delay;
217 
218 	if (monc->hunting)
219 		delay = CEPH_MONC_HUNT_INTERVAL * monc->hunt_mult;
220 	else
221 		delay = CEPH_MONC_PING_INTERVAL;
222 
223 	dout("__schedule_delayed after %lu\n", delay);
224 	mod_delayed_work(system_wq, &monc->delayed_work,
225 			 round_jiffies_relative(delay));
226 }
227 
228 const char *ceph_sub_str[] = {
229 	[CEPH_SUB_MONMAP] = "monmap",
230 	[CEPH_SUB_OSDMAP] = "osdmap",
231 	[CEPH_SUB_FSMAP]  = "fsmap.user",
232 	[CEPH_SUB_MDSMAP] = "mdsmap",
233 };
234 
235 /*
236  * Send subscribe request for one or more maps, according to
237  * monc->subs.
238  */
239 static void __send_subscribe(struct ceph_mon_client *monc)
240 {
241 	struct ceph_msg *msg = monc->m_subscribe;
242 	void *p = msg->front.iov_base;
243 	void *const end = p + msg->front_alloc_len;
244 	int num = 0;
245 	int i;
246 
247 	dout("%s sent %lu\n", __func__, monc->sub_renew_sent);
248 
249 	BUG_ON(monc->cur_mon < 0);
250 
251 	if (!monc->sub_renew_sent)
252 		monc->sub_renew_sent = jiffies | 1; /* never 0 */
253 
254 	msg->hdr.version = cpu_to_le16(2);
255 
256 	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
257 		if (monc->subs[i].want)
258 			num++;
259 	}
260 	BUG_ON(num < 1); /* monmap sub is always there */
261 	ceph_encode_32(&p, num);
262 	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
263 		char buf[32];
264 		int len;
265 
266 		if (!monc->subs[i].want)
267 			continue;
268 
269 		len = sprintf(buf, "%s", ceph_sub_str[i]);
270 		if (i == CEPH_SUB_MDSMAP &&
271 		    monc->fs_cluster_id != CEPH_FS_CLUSTER_ID_NONE)
272 			len += sprintf(buf + len, ".%d", monc->fs_cluster_id);
273 
274 		dout("%s %s start %llu flags 0x%x\n", __func__, buf,
275 		     le64_to_cpu(monc->subs[i].item.start),
276 		     monc->subs[i].item.flags);
277 		ceph_encode_string(&p, end, buf, len);
278 		memcpy(p, &monc->subs[i].item, sizeof(monc->subs[i].item));
279 		p += sizeof(monc->subs[i].item);
280 	}
281 
282 	BUG_ON(p > end);
283 	msg->front.iov_len = p - msg->front.iov_base;
284 	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
285 	ceph_msg_revoke(msg);
286 	ceph_con_send(&monc->con, ceph_msg_get(msg));
287 }
288 
289 static void handle_subscribe_ack(struct ceph_mon_client *monc,
290 				 struct ceph_msg *msg)
291 {
292 	unsigned int seconds;
293 	struct ceph_mon_subscribe_ack *h = msg->front.iov_base;
294 
295 	if (msg->front.iov_len < sizeof(*h))
296 		goto bad;
297 	seconds = le32_to_cpu(h->duration);
298 
299 	mutex_lock(&monc->mutex);
300 	if (monc->sub_renew_sent) {
301 		/*
302 		 * This is only needed for legacy (infernalis or older)
303 		 * MONs -- see delayed_work().
304 		 */
305 		monc->sub_renew_after = monc->sub_renew_sent +
306 					    (seconds >> 1) * HZ - 1;
307 		dout("%s sent %lu duration %d renew after %lu\n", __func__,
308 		     monc->sub_renew_sent, seconds, monc->sub_renew_after);
309 		monc->sub_renew_sent = 0;
310 	} else {
311 		dout("%s sent %lu renew after %lu, ignoring\n", __func__,
312 		     monc->sub_renew_sent, monc->sub_renew_after);
313 	}
314 	mutex_unlock(&monc->mutex);
315 	return;
316 bad:
317 	pr_err("got corrupt subscribe-ack msg\n");
318 	ceph_msg_dump(msg);
319 }
320 
321 /*
322  * Register interest in a map
323  *
324  * @sub: one of CEPH_SUB_*
325  * @epoch: X for "every map since X", or 0 for "just the latest"
326  */
327 static bool __ceph_monc_want_map(struct ceph_mon_client *monc, int sub,
328 				 u32 epoch, bool continuous)
329 {
330 	__le64 start = cpu_to_le64(epoch);
331 	u8 flags = !continuous ? CEPH_SUBSCRIBE_ONETIME : 0;
332 
333 	dout("%s %s epoch %u continuous %d\n", __func__, ceph_sub_str[sub],
334 	     epoch, continuous);
335 
336 	if (monc->subs[sub].want &&
337 	    monc->subs[sub].item.start == start &&
338 	    monc->subs[sub].item.flags == flags)
339 		return false;
340 
341 	monc->subs[sub].item.start = start;
342 	monc->subs[sub].item.flags = flags;
343 	monc->subs[sub].want = true;
344 
345 	return true;
346 }
347 
348 bool ceph_monc_want_map(struct ceph_mon_client *monc, int sub, u32 epoch,
349 			bool continuous)
350 {
351 	bool need_request;
352 
353 	mutex_lock(&monc->mutex);
354 	need_request = __ceph_monc_want_map(monc, sub, epoch, continuous);
355 	mutex_unlock(&monc->mutex);
356 
357 	return need_request;
358 }
359 EXPORT_SYMBOL(ceph_monc_want_map);
360 
361 /*
362  * Keep track of which maps we have
363  *
364  * @sub: one of CEPH_SUB_*
365  */
366 static void __ceph_monc_got_map(struct ceph_mon_client *monc, int sub,
367 				u32 epoch)
368 {
369 	dout("%s %s epoch %u\n", __func__, ceph_sub_str[sub], epoch);
370 
371 	if (monc->subs[sub].want) {
372 		if (monc->subs[sub].item.flags & CEPH_SUBSCRIBE_ONETIME)
373 			monc->subs[sub].want = false;
374 		else
375 			monc->subs[sub].item.start = cpu_to_le64(epoch + 1);
376 	}
377 
378 	monc->subs[sub].have = epoch;
379 }
380 
381 void ceph_monc_got_map(struct ceph_mon_client *monc, int sub, u32 epoch)
382 {
383 	mutex_lock(&monc->mutex);
384 	__ceph_monc_got_map(monc, sub, epoch);
385 	mutex_unlock(&monc->mutex);
386 }
387 EXPORT_SYMBOL(ceph_monc_got_map);
388 
389 void ceph_monc_renew_subs(struct ceph_mon_client *monc)
390 {
391 	mutex_lock(&monc->mutex);
392 	__send_subscribe(monc);
393 	mutex_unlock(&monc->mutex);
394 }
395 EXPORT_SYMBOL(ceph_monc_renew_subs);
396 
397 /*
398  * Wait for an osdmap with a given epoch.
399  *
400  * @epoch: epoch to wait for
401  * @timeout: in jiffies, 0 means "wait forever"
402  */
403 int ceph_monc_wait_osdmap(struct ceph_mon_client *monc, u32 epoch,
404 			  unsigned long timeout)
405 {
406 	unsigned long started = jiffies;
407 	long ret;
408 
409 	mutex_lock(&monc->mutex);
410 	while (monc->subs[CEPH_SUB_OSDMAP].have < epoch) {
411 		mutex_unlock(&monc->mutex);
412 
413 		if (timeout && time_after_eq(jiffies, started + timeout))
414 			return -ETIMEDOUT;
415 
416 		ret = wait_event_interruptible_timeout(monc->client->auth_wq,
417 				     monc->subs[CEPH_SUB_OSDMAP].have >= epoch,
418 				     ceph_timeout_jiffies(timeout));
419 		if (ret < 0)
420 			return ret;
421 
422 		mutex_lock(&monc->mutex);
423 	}
424 
425 	mutex_unlock(&monc->mutex);
426 	return 0;
427 }
428 EXPORT_SYMBOL(ceph_monc_wait_osdmap);
429 
430 /*
431  * Open a session with a random monitor.  Request monmap and osdmap,
432  * which are waited upon in __ceph_open_session().
433  */
434 int ceph_monc_open_session(struct ceph_mon_client *monc)
435 {
436 	mutex_lock(&monc->mutex);
437 	__ceph_monc_want_map(monc, CEPH_SUB_MONMAP, 0, true);
438 	__ceph_monc_want_map(monc, CEPH_SUB_OSDMAP, 0, false);
439 	__open_session(monc);
440 	__schedule_delayed(monc);
441 	mutex_unlock(&monc->mutex);
442 	return 0;
443 }
444 EXPORT_SYMBOL(ceph_monc_open_session);
445 
446 static void ceph_monc_handle_map(struct ceph_mon_client *monc,
447 				 struct ceph_msg *msg)
448 {
449 	struct ceph_client *client = monc->client;
450 	struct ceph_monmap *monmap = NULL, *old = monc->monmap;
451 	void *p, *end;
452 
453 	mutex_lock(&monc->mutex);
454 
455 	dout("handle_monmap\n");
456 	p = msg->front.iov_base;
457 	end = p + msg->front.iov_len;
458 
459 	monmap = ceph_monmap_decode(p, end);
460 	if (IS_ERR(monmap)) {
461 		pr_err("problem decoding monmap, %d\n",
462 		       (int)PTR_ERR(monmap));
463 		goto out;
464 	}
465 
466 	if (ceph_check_fsid(monc->client, &monmap->fsid) < 0) {
467 		kfree(monmap);
468 		goto out;
469 	}
470 
471 	client->monc.monmap = monmap;
472 	kfree(old);
473 
474 	__ceph_monc_got_map(monc, CEPH_SUB_MONMAP, monc->monmap->epoch);
475 	client->have_fsid = true;
476 
477 out:
478 	mutex_unlock(&monc->mutex);
479 	wake_up_all(&client->auth_wq);
480 }
481 
482 /*
483  * generic requests (currently statfs, mon_get_version)
484  */
485 DEFINE_RB_FUNCS(generic_request, struct ceph_mon_generic_request, tid, node)
486 
487 static void release_generic_request(struct kref *kref)
488 {
489 	struct ceph_mon_generic_request *req =
490 		container_of(kref, struct ceph_mon_generic_request, kref);
491 
492 	dout("%s greq %p request %p reply %p\n", __func__, req, req->request,
493 	     req->reply);
494 	WARN_ON(!RB_EMPTY_NODE(&req->node));
495 
496 	if (req->reply)
497 		ceph_msg_put(req->reply);
498 	if (req->request)
499 		ceph_msg_put(req->request);
500 
501 	kfree(req);
502 }
503 
504 static void put_generic_request(struct ceph_mon_generic_request *req)
505 {
506 	if (req)
507 		kref_put(&req->kref, release_generic_request);
508 }
509 
510 static void get_generic_request(struct ceph_mon_generic_request *req)
511 {
512 	kref_get(&req->kref);
513 }
514 
515 static struct ceph_mon_generic_request *
516 alloc_generic_request(struct ceph_mon_client *monc, gfp_t gfp)
517 {
518 	struct ceph_mon_generic_request *req;
519 
520 	req = kzalloc(sizeof(*req), gfp);
521 	if (!req)
522 		return NULL;
523 
524 	req->monc = monc;
525 	kref_init(&req->kref);
526 	RB_CLEAR_NODE(&req->node);
527 	init_completion(&req->completion);
528 
529 	dout("%s greq %p\n", __func__, req);
530 	return req;
531 }
532 
533 static void register_generic_request(struct ceph_mon_generic_request *req)
534 {
535 	struct ceph_mon_client *monc = req->monc;
536 
537 	WARN_ON(req->tid);
538 
539 	get_generic_request(req);
540 	req->tid = ++monc->last_tid;
541 	insert_generic_request(&monc->generic_request_tree, req);
542 }
543 
544 static void send_generic_request(struct ceph_mon_client *monc,
545 				 struct ceph_mon_generic_request *req)
546 {
547 	WARN_ON(!req->tid);
548 
549 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
550 	req->request->hdr.tid = cpu_to_le64(req->tid);
551 	ceph_con_send(&monc->con, ceph_msg_get(req->request));
552 }
553 
554 static void __finish_generic_request(struct ceph_mon_generic_request *req)
555 {
556 	struct ceph_mon_client *monc = req->monc;
557 
558 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
559 	erase_generic_request(&monc->generic_request_tree, req);
560 
561 	ceph_msg_revoke(req->request);
562 	ceph_msg_revoke_incoming(req->reply);
563 }
564 
565 static void finish_generic_request(struct ceph_mon_generic_request *req)
566 {
567 	__finish_generic_request(req);
568 	put_generic_request(req);
569 }
570 
571 static void complete_generic_request(struct ceph_mon_generic_request *req)
572 {
573 	if (req->complete_cb)
574 		req->complete_cb(req);
575 	else
576 		complete_all(&req->completion);
577 	put_generic_request(req);
578 }
579 
580 static void cancel_generic_request(struct ceph_mon_generic_request *req)
581 {
582 	struct ceph_mon_client *monc = req->monc;
583 	struct ceph_mon_generic_request *lookup_req;
584 
585 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
586 
587 	mutex_lock(&monc->mutex);
588 	lookup_req = lookup_generic_request(&monc->generic_request_tree,
589 					    req->tid);
590 	if (lookup_req) {
591 		WARN_ON(lookup_req != req);
592 		finish_generic_request(req);
593 	}
594 
595 	mutex_unlock(&monc->mutex);
596 }
597 
598 static int wait_generic_request(struct ceph_mon_generic_request *req)
599 {
600 	int ret;
601 
602 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
603 	ret = wait_for_completion_interruptible(&req->completion);
604 	if (ret)
605 		cancel_generic_request(req);
606 	else
607 		ret = req->result; /* completed */
608 
609 	return ret;
610 }
611 
612 static struct ceph_msg *get_generic_reply(struct ceph_connection *con,
613 					 struct ceph_msg_header *hdr,
614 					 int *skip)
615 {
616 	struct ceph_mon_client *monc = con->private;
617 	struct ceph_mon_generic_request *req;
618 	u64 tid = le64_to_cpu(hdr->tid);
619 	struct ceph_msg *m;
620 
621 	mutex_lock(&monc->mutex);
622 	req = lookup_generic_request(&monc->generic_request_tree, tid);
623 	if (!req) {
624 		dout("get_generic_reply %lld dne\n", tid);
625 		*skip = 1;
626 		m = NULL;
627 	} else {
628 		dout("get_generic_reply %lld got %p\n", tid, req->reply);
629 		*skip = 0;
630 		m = ceph_msg_get(req->reply);
631 		/*
632 		 * we don't need to track the connection reading into
633 		 * this reply because we only have one open connection
634 		 * at a time, ever.
635 		 */
636 	}
637 	mutex_unlock(&monc->mutex);
638 	return m;
639 }
640 
641 /*
642  * statfs
643  */
644 static void handle_statfs_reply(struct ceph_mon_client *monc,
645 				struct ceph_msg *msg)
646 {
647 	struct ceph_mon_generic_request *req;
648 	struct ceph_mon_statfs_reply *reply = msg->front.iov_base;
649 	u64 tid = le64_to_cpu(msg->hdr.tid);
650 
651 	dout("%s msg %p tid %llu\n", __func__, msg, tid);
652 
653 	if (msg->front.iov_len != sizeof(*reply))
654 		goto bad;
655 
656 	mutex_lock(&monc->mutex);
657 	req = lookup_generic_request(&monc->generic_request_tree, tid);
658 	if (!req) {
659 		mutex_unlock(&monc->mutex);
660 		return;
661 	}
662 
663 	req->result = 0;
664 	*req->u.st = reply->st; /* struct */
665 	__finish_generic_request(req);
666 	mutex_unlock(&monc->mutex);
667 
668 	complete_generic_request(req);
669 	return;
670 
671 bad:
672 	pr_err("corrupt statfs reply, tid %llu\n", tid);
673 	ceph_msg_dump(msg);
674 }
675 
676 /*
677  * Do a synchronous statfs().
678  */
679 int ceph_monc_do_statfs(struct ceph_mon_client *monc, u64 data_pool,
680 			struct ceph_statfs *buf)
681 {
682 	struct ceph_mon_generic_request *req;
683 	struct ceph_mon_statfs *h;
684 	int ret = -ENOMEM;
685 
686 	req = alloc_generic_request(monc, GFP_NOFS);
687 	if (!req)
688 		goto out;
689 
690 	req->request = ceph_msg_new(CEPH_MSG_STATFS, sizeof(*h), GFP_NOFS,
691 				    true);
692 	if (!req->request)
693 		goto out;
694 
695 	req->reply = ceph_msg_new(CEPH_MSG_STATFS_REPLY, 64, GFP_NOFS, true);
696 	if (!req->reply)
697 		goto out;
698 
699 	req->u.st = buf;
700 	req->request->hdr.version = cpu_to_le16(2);
701 
702 	mutex_lock(&monc->mutex);
703 	register_generic_request(req);
704 	/* fill out request */
705 	h = req->request->front.iov_base;
706 	h->monhdr.have_version = 0;
707 	h->monhdr.session_mon = cpu_to_le16(-1);
708 	h->monhdr.session_mon_tid = 0;
709 	h->fsid = monc->monmap->fsid;
710 	h->contains_data_pool = (data_pool != CEPH_NOPOOL);
711 	h->data_pool = cpu_to_le64(data_pool);
712 	send_generic_request(monc, req);
713 	mutex_unlock(&monc->mutex);
714 
715 	ret = wait_generic_request(req);
716 out:
717 	put_generic_request(req);
718 	return ret;
719 }
720 EXPORT_SYMBOL(ceph_monc_do_statfs);
721 
722 static void handle_get_version_reply(struct ceph_mon_client *monc,
723 				     struct ceph_msg *msg)
724 {
725 	struct ceph_mon_generic_request *req;
726 	u64 tid = le64_to_cpu(msg->hdr.tid);
727 	void *p = msg->front.iov_base;
728 	void *end = p + msg->front_alloc_len;
729 	u64 handle;
730 
731 	dout("%s msg %p tid %llu\n", __func__, msg, tid);
732 
733 	ceph_decode_need(&p, end, 2*sizeof(u64), bad);
734 	handle = ceph_decode_64(&p);
735 	if (tid != 0 && tid != handle)
736 		goto bad;
737 
738 	mutex_lock(&monc->mutex);
739 	req = lookup_generic_request(&monc->generic_request_tree, handle);
740 	if (!req) {
741 		mutex_unlock(&monc->mutex);
742 		return;
743 	}
744 
745 	req->result = 0;
746 	req->u.newest = ceph_decode_64(&p);
747 	__finish_generic_request(req);
748 	mutex_unlock(&monc->mutex);
749 
750 	complete_generic_request(req);
751 	return;
752 
753 bad:
754 	pr_err("corrupt mon_get_version reply, tid %llu\n", tid);
755 	ceph_msg_dump(msg);
756 }
757 
758 static struct ceph_mon_generic_request *
759 __ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
760 			ceph_monc_callback_t cb, u64 private_data)
761 {
762 	struct ceph_mon_generic_request *req;
763 
764 	req = alloc_generic_request(monc, GFP_NOIO);
765 	if (!req)
766 		goto err_put_req;
767 
768 	req->request = ceph_msg_new(CEPH_MSG_MON_GET_VERSION,
769 				    sizeof(u64) + sizeof(u32) + strlen(what),
770 				    GFP_NOIO, true);
771 	if (!req->request)
772 		goto err_put_req;
773 
774 	req->reply = ceph_msg_new(CEPH_MSG_MON_GET_VERSION_REPLY, 32, GFP_NOIO,
775 				  true);
776 	if (!req->reply)
777 		goto err_put_req;
778 
779 	req->complete_cb = cb;
780 	req->private_data = private_data;
781 
782 	mutex_lock(&monc->mutex);
783 	register_generic_request(req);
784 	{
785 		void *p = req->request->front.iov_base;
786 		void *const end = p + req->request->front_alloc_len;
787 
788 		ceph_encode_64(&p, req->tid); /* handle */
789 		ceph_encode_string(&p, end, what, strlen(what));
790 		WARN_ON(p != end);
791 	}
792 	send_generic_request(monc, req);
793 	mutex_unlock(&monc->mutex);
794 
795 	return req;
796 
797 err_put_req:
798 	put_generic_request(req);
799 	return ERR_PTR(-ENOMEM);
800 }
801 
802 /*
803  * Send MMonGetVersion and wait for the reply.
804  *
805  * @what: one of "mdsmap", "osdmap" or "monmap"
806  */
807 int ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
808 			  u64 *newest)
809 {
810 	struct ceph_mon_generic_request *req;
811 	int ret;
812 
813 	req = __ceph_monc_get_version(monc, what, NULL, 0);
814 	if (IS_ERR(req))
815 		return PTR_ERR(req);
816 
817 	ret = wait_generic_request(req);
818 	if (!ret)
819 		*newest = req->u.newest;
820 
821 	put_generic_request(req);
822 	return ret;
823 }
824 EXPORT_SYMBOL(ceph_monc_get_version);
825 
826 /*
827  * Send MMonGetVersion,
828  *
829  * @what: one of "mdsmap", "osdmap" or "monmap"
830  */
831 int ceph_monc_get_version_async(struct ceph_mon_client *monc, const char *what,
832 				ceph_monc_callback_t cb, u64 private_data)
833 {
834 	struct ceph_mon_generic_request *req;
835 
836 	req = __ceph_monc_get_version(monc, what, cb, private_data);
837 	if (IS_ERR(req))
838 		return PTR_ERR(req);
839 
840 	put_generic_request(req);
841 	return 0;
842 }
843 EXPORT_SYMBOL(ceph_monc_get_version_async);
844 
845 static void handle_command_ack(struct ceph_mon_client *monc,
846 			       struct ceph_msg *msg)
847 {
848 	struct ceph_mon_generic_request *req;
849 	void *p = msg->front.iov_base;
850 	void *const end = p + msg->front_alloc_len;
851 	u64 tid = le64_to_cpu(msg->hdr.tid);
852 
853 	dout("%s msg %p tid %llu\n", __func__, msg, tid);
854 
855 	ceph_decode_need(&p, end, sizeof(struct ceph_mon_request_header) +
856 							    sizeof(u32), bad);
857 	p += sizeof(struct ceph_mon_request_header);
858 
859 	mutex_lock(&monc->mutex);
860 	req = lookup_generic_request(&monc->generic_request_tree, tid);
861 	if (!req) {
862 		mutex_unlock(&monc->mutex);
863 		return;
864 	}
865 
866 	req->result = ceph_decode_32(&p);
867 	__finish_generic_request(req);
868 	mutex_unlock(&monc->mutex);
869 
870 	complete_generic_request(req);
871 	return;
872 
873 bad:
874 	pr_err("corrupt mon_command ack, tid %llu\n", tid);
875 	ceph_msg_dump(msg);
876 }
877 
878 int ceph_monc_blacklist_add(struct ceph_mon_client *monc,
879 			    struct ceph_entity_addr *client_addr)
880 {
881 	struct ceph_mon_generic_request *req;
882 	struct ceph_mon_command *h;
883 	int ret = -ENOMEM;
884 	int len;
885 
886 	req = alloc_generic_request(monc, GFP_NOIO);
887 	if (!req)
888 		goto out;
889 
890 	req->request = ceph_msg_new(CEPH_MSG_MON_COMMAND, 256, GFP_NOIO, true);
891 	if (!req->request)
892 		goto out;
893 
894 	req->reply = ceph_msg_new(CEPH_MSG_MON_COMMAND_ACK, 512, GFP_NOIO,
895 				  true);
896 	if (!req->reply)
897 		goto out;
898 
899 	mutex_lock(&monc->mutex);
900 	register_generic_request(req);
901 	h = req->request->front.iov_base;
902 	h->monhdr.have_version = 0;
903 	h->monhdr.session_mon = cpu_to_le16(-1);
904 	h->monhdr.session_mon_tid = 0;
905 	h->fsid = monc->monmap->fsid;
906 	h->num_strs = cpu_to_le32(1);
907 	len = sprintf(h->str, "{ \"prefix\": \"osd blacklist\", \
908 		                 \"blacklistop\": \"add\", \
909 				 \"addr\": \"%pISpc/%u\" }",
910 		      &client_addr->in_addr, le32_to_cpu(client_addr->nonce));
911 	h->str_len = cpu_to_le32(len);
912 	send_generic_request(monc, req);
913 	mutex_unlock(&monc->mutex);
914 
915 	ret = wait_generic_request(req);
916 out:
917 	put_generic_request(req);
918 	return ret;
919 }
920 EXPORT_SYMBOL(ceph_monc_blacklist_add);
921 
922 /*
923  * Resend pending generic requests.
924  */
925 static void __resend_generic_request(struct ceph_mon_client *monc)
926 {
927 	struct ceph_mon_generic_request *req;
928 	struct rb_node *p;
929 
930 	for (p = rb_first(&monc->generic_request_tree); p; p = rb_next(p)) {
931 		req = rb_entry(p, struct ceph_mon_generic_request, node);
932 		ceph_msg_revoke(req->request);
933 		ceph_msg_revoke_incoming(req->reply);
934 		ceph_con_send(&monc->con, ceph_msg_get(req->request));
935 	}
936 }
937 
938 /*
939  * Delayed work.  If we haven't mounted yet, retry.  Otherwise,
940  * renew/retry subscription as needed (in case it is timing out, or we
941  * got an ENOMEM).  And keep the monitor connection alive.
942  */
943 static void delayed_work(struct work_struct *work)
944 {
945 	struct ceph_mon_client *monc =
946 		container_of(work, struct ceph_mon_client, delayed_work.work);
947 
948 	dout("monc delayed_work\n");
949 	mutex_lock(&monc->mutex);
950 	if (monc->hunting) {
951 		dout("%s continuing hunt\n", __func__);
952 		reopen_session(monc);
953 	} else {
954 		int is_auth = ceph_auth_is_authenticated(monc->auth);
955 		if (ceph_con_keepalive_expired(&monc->con,
956 					       CEPH_MONC_PING_TIMEOUT)) {
957 			dout("monc keepalive timeout\n");
958 			is_auth = 0;
959 			reopen_session(monc);
960 		}
961 
962 		if (!monc->hunting) {
963 			ceph_con_keepalive(&monc->con);
964 			__validate_auth(monc);
965 		}
966 
967 		if (is_auth &&
968 		    !(monc->con.peer_features & CEPH_FEATURE_MON_STATEFUL_SUB)) {
969 			unsigned long now = jiffies;
970 
971 			dout("%s renew subs? now %lu renew after %lu\n",
972 			     __func__, now, monc->sub_renew_after);
973 			if (time_after_eq(now, monc->sub_renew_after))
974 				__send_subscribe(monc);
975 		}
976 	}
977 	__schedule_delayed(monc);
978 	mutex_unlock(&monc->mutex);
979 }
980 
981 /*
982  * On startup, we build a temporary monmap populated with the IPs
983  * provided by mount(2).
984  */
985 static int build_initial_monmap(struct ceph_mon_client *monc)
986 {
987 	struct ceph_options *opt = monc->client->options;
988 	struct ceph_entity_addr *mon_addr = opt->mon_addr;
989 	int num_mon = opt->num_mon;
990 	int i;
991 
992 	/* build initial monmap */
993 	monc->monmap = kzalloc(sizeof(*monc->monmap) +
994 			       num_mon*sizeof(monc->monmap->mon_inst[0]),
995 			       GFP_KERNEL);
996 	if (!monc->monmap)
997 		return -ENOMEM;
998 	for (i = 0; i < num_mon; i++) {
999 		monc->monmap->mon_inst[i].addr = mon_addr[i];
1000 		monc->monmap->mon_inst[i].addr.nonce = 0;
1001 		monc->monmap->mon_inst[i].name.type =
1002 			CEPH_ENTITY_TYPE_MON;
1003 		monc->monmap->mon_inst[i].name.num = cpu_to_le64(i);
1004 	}
1005 	monc->monmap->num_mon = num_mon;
1006 	return 0;
1007 }
1008 
1009 int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
1010 {
1011 	int err = 0;
1012 
1013 	dout("init\n");
1014 	memset(monc, 0, sizeof(*monc));
1015 	monc->client = cl;
1016 	monc->monmap = NULL;
1017 	mutex_init(&monc->mutex);
1018 
1019 	err = build_initial_monmap(monc);
1020 	if (err)
1021 		goto out;
1022 
1023 	/* connection */
1024 	/* authentication */
1025 	monc->auth = ceph_auth_init(cl->options->name,
1026 				    cl->options->key);
1027 	if (IS_ERR(monc->auth)) {
1028 		err = PTR_ERR(monc->auth);
1029 		goto out_monmap;
1030 	}
1031 	monc->auth->want_keys =
1032 		CEPH_ENTITY_TYPE_AUTH | CEPH_ENTITY_TYPE_MON |
1033 		CEPH_ENTITY_TYPE_OSD | CEPH_ENTITY_TYPE_MDS;
1034 
1035 	/* msgs */
1036 	err = -ENOMEM;
1037 	monc->m_subscribe_ack = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE_ACK,
1038 				     sizeof(struct ceph_mon_subscribe_ack),
1039 				     GFP_KERNEL, true);
1040 	if (!monc->m_subscribe_ack)
1041 		goto out_auth;
1042 
1043 	monc->m_subscribe = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 128,
1044 					 GFP_KERNEL, true);
1045 	if (!monc->m_subscribe)
1046 		goto out_subscribe_ack;
1047 
1048 	monc->m_auth_reply = ceph_msg_new(CEPH_MSG_AUTH_REPLY, 4096,
1049 					  GFP_KERNEL, true);
1050 	if (!monc->m_auth_reply)
1051 		goto out_subscribe;
1052 
1053 	monc->m_auth = ceph_msg_new(CEPH_MSG_AUTH, 4096, GFP_KERNEL, true);
1054 	monc->pending_auth = 0;
1055 	if (!monc->m_auth)
1056 		goto out_auth_reply;
1057 
1058 	ceph_con_init(&monc->con, monc, &mon_con_ops,
1059 		      &monc->client->msgr);
1060 
1061 	monc->cur_mon = -1;
1062 	monc->had_a_connection = false;
1063 	monc->hunt_mult = 1;
1064 
1065 	INIT_DELAYED_WORK(&monc->delayed_work, delayed_work);
1066 	monc->generic_request_tree = RB_ROOT;
1067 	monc->last_tid = 0;
1068 
1069 	monc->fs_cluster_id = CEPH_FS_CLUSTER_ID_NONE;
1070 
1071 	return 0;
1072 
1073 out_auth_reply:
1074 	ceph_msg_put(monc->m_auth_reply);
1075 out_subscribe:
1076 	ceph_msg_put(monc->m_subscribe);
1077 out_subscribe_ack:
1078 	ceph_msg_put(monc->m_subscribe_ack);
1079 out_auth:
1080 	ceph_auth_destroy(monc->auth);
1081 out_monmap:
1082 	kfree(monc->monmap);
1083 out:
1084 	return err;
1085 }
1086 EXPORT_SYMBOL(ceph_monc_init);
1087 
1088 void ceph_monc_stop(struct ceph_mon_client *monc)
1089 {
1090 	dout("stop\n");
1091 	cancel_delayed_work_sync(&monc->delayed_work);
1092 
1093 	mutex_lock(&monc->mutex);
1094 	__close_session(monc);
1095 	monc->cur_mon = -1;
1096 	mutex_unlock(&monc->mutex);
1097 
1098 	/*
1099 	 * flush msgr queue before we destroy ourselves to ensure that:
1100 	 *  - any work that references our embedded con is finished.
1101 	 *  - any osd_client or other work that may reference an authorizer
1102 	 *    finishes before we shut down the auth subsystem.
1103 	 */
1104 	ceph_msgr_flush();
1105 
1106 	ceph_auth_destroy(monc->auth);
1107 
1108 	WARN_ON(!RB_EMPTY_ROOT(&monc->generic_request_tree));
1109 
1110 	ceph_msg_put(monc->m_auth);
1111 	ceph_msg_put(monc->m_auth_reply);
1112 	ceph_msg_put(monc->m_subscribe);
1113 	ceph_msg_put(monc->m_subscribe_ack);
1114 
1115 	kfree(monc->monmap);
1116 }
1117 EXPORT_SYMBOL(ceph_monc_stop);
1118 
1119 static void finish_hunting(struct ceph_mon_client *monc)
1120 {
1121 	if (monc->hunting) {
1122 		dout("%s found mon%d\n", __func__, monc->cur_mon);
1123 		monc->hunting = false;
1124 		monc->had_a_connection = true;
1125 		monc->hunt_mult /= 2; /* reduce by 50% */
1126 		if (monc->hunt_mult < 1)
1127 			monc->hunt_mult = 1;
1128 	}
1129 }
1130 
1131 static void handle_auth_reply(struct ceph_mon_client *monc,
1132 			      struct ceph_msg *msg)
1133 {
1134 	int ret;
1135 	int was_auth = 0;
1136 
1137 	mutex_lock(&monc->mutex);
1138 	was_auth = ceph_auth_is_authenticated(monc->auth);
1139 	monc->pending_auth = 0;
1140 	ret = ceph_handle_auth_reply(monc->auth, msg->front.iov_base,
1141 				     msg->front.iov_len,
1142 				     monc->m_auth->front.iov_base,
1143 				     monc->m_auth->front_alloc_len);
1144 	if (ret > 0) {
1145 		__send_prepared_auth_request(monc, ret);
1146 		goto out;
1147 	}
1148 
1149 	finish_hunting(monc);
1150 
1151 	if (ret < 0) {
1152 		monc->client->auth_err = ret;
1153 	} else if (!was_auth && ceph_auth_is_authenticated(monc->auth)) {
1154 		dout("authenticated, starting session\n");
1155 
1156 		monc->client->msgr.inst.name.type = CEPH_ENTITY_TYPE_CLIENT;
1157 		monc->client->msgr.inst.name.num =
1158 					cpu_to_le64(monc->auth->global_id);
1159 
1160 		__send_subscribe(monc);
1161 		__resend_generic_request(monc);
1162 
1163 		pr_info("mon%d %s session established\n", monc->cur_mon,
1164 			ceph_pr_addr(&monc->con.peer_addr.in_addr));
1165 	}
1166 
1167 out:
1168 	mutex_unlock(&monc->mutex);
1169 	if (monc->client->auth_err < 0)
1170 		wake_up_all(&monc->client->auth_wq);
1171 }
1172 
1173 static int __validate_auth(struct ceph_mon_client *monc)
1174 {
1175 	int ret;
1176 
1177 	if (monc->pending_auth)
1178 		return 0;
1179 
1180 	ret = ceph_build_auth(monc->auth, monc->m_auth->front.iov_base,
1181 			      monc->m_auth->front_alloc_len);
1182 	if (ret <= 0)
1183 		return ret; /* either an error, or no need to authenticate */
1184 	__send_prepared_auth_request(monc, ret);
1185 	return 0;
1186 }
1187 
1188 int ceph_monc_validate_auth(struct ceph_mon_client *monc)
1189 {
1190 	int ret;
1191 
1192 	mutex_lock(&monc->mutex);
1193 	ret = __validate_auth(monc);
1194 	mutex_unlock(&monc->mutex);
1195 	return ret;
1196 }
1197 EXPORT_SYMBOL(ceph_monc_validate_auth);
1198 
1199 /*
1200  * handle incoming message
1201  */
1202 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
1203 {
1204 	struct ceph_mon_client *monc = con->private;
1205 	int type = le16_to_cpu(msg->hdr.type);
1206 
1207 	if (!monc)
1208 		return;
1209 
1210 	switch (type) {
1211 	case CEPH_MSG_AUTH_REPLY:
1212 		handle_auth_reply(monc, msg);
1213 		break;
1214 
1215 	case CEPH_MSG_MON_SUBSCRIBE_ACK:
1216 		handle_subscribe_ack(monc, msg);
1217 		break;
1218 
1219 	case CEPH_MSG_STATFS_REPLY:
1220 		handle_statfs_reply(monc, msg);
1221 		break;
1222 
1223 	case CEPH_MSG_MON_GET_VERSION_REPLY:
1224 		handle_get_version_reply(monc, msg);
1225 		break;
1226 
1227 	case CEPH_MSG_MON_COMMAND_ACK:
1228 		handle_command_ack(monc, msg);
1229 		break;
1230 
1231 	case CEPH_MSG_MON_MAP:
1232 		ceph_monc_handle_map(monc, msg);
1233 		break;
1234 
1235 	case CEPH_MSG_OSD_MAP:
1236 		ceph_osdc_handle_map(&monc->client->osdc, msg);
1237 		break;
1238 
1239 	default:
1240 		/* can the chained handler handle it? */
1241 		if (monc->client->extra_mon_dispatch &&
1242 		    monc->client->extra_mon_dispatch(monc->client, msg) == 0)
1243 			break;
1244 
1245 		pr_err("received unknown message type %d %s\n", type,
1246 		       ceph_msg_type_name(type));
1247 	}
1248 	ceph_msg_put(msg);
1249 }
1250 
1251 /*
1252  * Allocate memory for incoming message
1253  */
1254 static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
1255 				      struct ceph_msg_header *hdr,
1256 				      int *skip)
1257 {
1258 	struct ceph_mon_client *monc = con->private;
1259 	int type = le16_to_cpu(hdr->type);
1260 	int front_len = le32_to_cpu(hdr->front_len);
1261 	struct ceph_msg *m = NULL;
1262 
1263 	*skip = 0;
1264 
1265 	switch (type) {
1266 	case CEPH_MSG_MON_SUBSCRIBE_ACK:
1267 		m = ceph_msg_get(monc->m_subscribe_ack);
1268 		break;
1269 	case CEPH_MSG_STATFS_REPLY:
1270 	case CEPH_MSG_MON_COMMAND_ACK:
1271 		return get_generic_reply(con, hdr, skip);
1272 	case CEPH_MSG_AUTH_REPLY:
1273 		m = ceph_msg_get(monc->m_auth_reply);
1274 		break;
1275 	case CEPH_MSG_MON_GET_VERSION_REPLY:
1276 		if (le64_to_cpu(hdr->tid) != 0)
1277 			return get_generic_reply(con, hdr, skip);
1278 
1279 		/*
1280 		 * Older OSDs don't set reply tid even if the orignal
1281 		 * request had a non-zero tid.  Workaround this weirdness
1282 		 * by falling through to the allocate case.
1283 		 */
1284 	case CEPH_MSG_MON_MAP:
1285 	case CEPH_MSG_MDS_MAP:
1286 	case CEPH_MSG_OSD_MAP:
1287 	case CEPH_MSG_FS_MAP_USER:
1288 		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
1289 		if (!m)
1290 			return NULL;	/* ENOMEM--return skip == 0 */
1291 		break;
1292 	}
1293 
1294 	if (!m) {
1295 		pr_info("alloc_msg unknown type %d\n", type);
1296 		*skip = 1;
1297 	} else if (front_len > m->front_alloc_len) {
1298 		pr_warn("mon_alloc_msg front %d > prealloc %d (%u#%llu)\n",
1299 			front_len, m->front_alloc_len,
1300 			(unsigned int)con->peer_name.type,
1301 			le64_to_cpu(con->peer_name.num));
1302 		ceph_msg_put(m);
1303 		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
1304 	}
1305 
1306 	return m;
1307 }
1308 
1309 /*
1310  * If the monitor connection resets, pick a new monitor and resubmit
1311  * any pending requests.
1312  */
1313 static void mon_fault(struct ceph_connection *con)
1314 {
1315 	struct ceph_mon_client *monc = con->private;
1316 
1317 	mutex_lock(&monc->mutex);
1318 	dout("%s mon%d\n", __func__, monc->cur_mon);
1319 	if (monc->cur_mon >= 0) {
1320 		if (!monc->hunting) {
1321 			dout("%s hunting for new mon\n", __func__);
1322 			reopen_session(monc);
1323 			__schedule_delayed(monc);
1324 		} else {
1325 			dout("%s already hunting\n", __func__);
1326 		}
1327 	}
1328 	mutex_unlock(&monc->mutex);
1329 }
1330 
1331 /*
1332  * We can ignore refcounting on the connection struct, as all references
1333  * will come from the messenger workqueue, which is drained prior to
1334  * mon_client destruction.
1335  */
1336 static struct ceph_connection *con_get(struct ceph_connection *con)
1337 {
1338 	return con;
1339 }
1340 
1341 static void con_put(struct ceph_connection *con)
1342 {
1343 }
1344 
1345 static const struct ceph_connection_operations mon_con_ops = {
1346 	.get = con_get,
1347 	.put = con_put,
1348 	.dispatch = dispatch,
1349 	.fault = mon_fault,
1350 	.alloc_msg = mon_alloc_msg,
1351 };
1352