xref: /openbmc/linux/net/ceph/mon_client.c (revision b732539e)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ceph/ceph_debug.h>
3 
4 #include <linux/module.h>
5 #include <linux/types.h>
6 #include <linux/slab.h>
7 #include <linux/random.h>
8 #include <linux/sched.h>
9 
10 #include <linux/ceph/ceph_features.h>
11 #include <linux/ceph/mon_client.h>
12 #include <linux/ceph/libceph.h>
13 #include <linux/ceph/debugfs.h>
14 #include <linux/ceph/decode.h>
15 #include <linux/ceph/auth.h>
16 
17 /*
18  * Interact with Ceph monitor cluster.  Handle requests for new map
19  * versions, and periodically resend as needed.  Also implement
20  * statfs() and umount().
21  *
22  * A small cluster of Ceph "monitors" are responsible for managing critical
23  * cluster configuration and state information.  An odd number (e.g., 3, 5)
24  * of cmon daemons use a modified version of the Paxos part-time parliament
25  * algorithm to manage the MDS map (mds cluster membership), OSD map, and
26  * list of clients who have mounted the file system.
27  *
28  * We maintain an open, active session with a monitor at all times in order to
29  * receive timely MDSMap updates.  We periodically send a keepalive byte on the
30  * TCP socket to ensure we detect a failure.  If the connection does break, we
31  * randomly hunt for a new monitor.  Once the connection is reestablished, we
32  * resend any outstanding requests.
33  */
34 
35 static const struct ceph_connection_operations mon_con_ops;
36 
37 static int __validate_auth(struct ceph_mon_client *monc);
38 
39 /*
40  * Decode a monmap blob (e.g., during mount).
41  */
42 struct ceph_monmap *ceph_monmap_decode(void *p, void *end)
43 {
44 	struct ceph_monmap *m = NULL;
45 	int i, err = -EINVAL;
46 	struct ceph_fsid fsid;
47 	u32 epoch, num_mon;
48 	u32 len;
49 
50 	ceph_decode_32_safe(&p, end, len, bad);
51 	ceph_decode_need(&p, end, len, bad);
52 
53 	dout("monmap_decode %p %p len %d\n", p, end, (int)(end-p));
54 	p += sizeof(u16);  /* skip version */
55 
56 	ceph_decode_need(&p, end, sizeof(fsid) + 2*sizeof(u32), bad);
57 	ceph_decode_copy(&p, &fsid, sizeof(fsid));
58 	epoch = ceph_decode_32(&p);
59 
60 	num_mon = ceph_decode_32(&p);
61 	ceph_decode_need(&p, end, num_mon*sizeof(m->mon_inst[0]), bad);
62 
63 	if (num_mon > CEPH_MAX_MON)
64 		goto bad;
65 	m = kmalloc(sizeof(*m) + sizeof(m->mon_inst[0])*num_mon, GFP_NOFS);
66 	if (m == NULL)
67 		return ERR_PTR(-ENOMEM);
68 	m->fsid = fsid;
69 	m->epoch = epoch;
70 	m->num_mon = num_mon;
71 	ceph_decode_copy(&p, m->mon_inst, num_mon*sizeof(m->mon_inst[0]));
72 	for (i = 0; i < num_mon; i++)
73 		ceph_decode_addr(&m->mon_inst[i].addr);
74 
75 	dout("monmap_decode epoch %d, num_mon %d\n", m->epoch,
76 	     m->num_mon);
77 	for (i = 0; i < m->num_mon; i++)
78 		dout("monmap_decode  mon%d is %s\n", i,
79 		     ceph_pr_addr(&m->mon_inst[i].addr.in_addr));
80 	return m;
81 
82 bad:
83 	dout("monmap_decode failed with %d\n", err);
84 	kfree(m);
85 	return ERR_PTR(err);
86 }
87 
88 /*
89  * return true if *addr is included in the monmap.
90  */
91 int ceph_monmap_contains(struct ceph_monmap *m, struct ceph_entity_addr *addr)
92 {
93 	int i;
94 
95 	for (i = 0; i < m->num_mon; i++)
96 		if (memcmp(addr, &m->mon_inst[i].addr, sizeof(*addr)) == 0)
97 			return 1;
98 	return 0;
99 }
100 
101 /*
102  * Send an auth request.
103  */
104 static void __send_prepared_auth_request(struct ceph_mon_client *monc, int len)
105 {
106 	monc->pending_auth = 1;
107 	monc->m_auth->front.iov_len = len;
108 	monc->m_auth->hdr.front_len = cpu_to_le32(len);
109 	ceph_msg_revoke(monc->m_auth);
110 	ceph_msg_get(monc->m_auth);  /* keep our ref */
111 	ceph_con_send(&monc->con, monc->m_auth);
112 }
113 
114 /*
115  * Close monitor session, if any.
116  */
117 static void __close_session(struct ceph_mon_client *monc)
118 {
119 	dout("__close_session closing mon%d\n", monc->cur_mon);
120 	ceph_msg_revoke(monc->m_auth);
121 	ceph_msg_revoke_incoming(monc->m_auth_reply);
122 	ceph_msg_revoke(monc->m_subscribe);
123 	ceph_msg_revoke_incoming(monc->m_subscribe_ack);
124 	ceph_con_close(&monc->con);
125 
126 	monc->pending_auth = 0;
127 	ceph_auth_reset(monc->auth);
128 }
129 
130 /*
131  * Pick a new monitor at random and set cur_mon.  If we are repicking
132  * (i.e. cur_mon is already set), be sure to pick a different one.
133  */
134 static void pick_new_mon(struct ceph_mon_client *monc)
135 {
136 	int old_mon = monc->cur_mon;
137 
138 	BUG_ON(monc->monmap->num_mon < 1);
139 
140 	if (monc->monmap->num_mon == 1) {
141 		monc->cur_mon = 0;
142 	} else {
143 		int max = monc->monmap->num_mon;
144 		int o = -1;
145 		int n;
146 
147 		if (monc->cur_mon >= 0) {
148 			if (monc->cur_mon < monc->monmap->num_mon)
149 				o = monc->cur_mon;
150 			if (o >= 0)
151 				max--;
152 		}
153 
154 		n = prandom_u32() % max;
155 		if (o >= 0 && n >= o)
156 			n++;
157 
158 		monc->cur_mon = n;
159 	}
160 
161 	dout("%s mon%d -> mon%d out of %d mons\n", __func__, old_mon,
162 	     monc->cur_mon, monc->monmap->num_mon);
163 }
164 
165 /*
166  * Open a session with a new monitor.
167  */
168 static void __open_session(struct ceph_mon_client *monc)
169 {
170 	int ret;
171 
172 	pick_new_mon(monc);
173 
174 	monc->hunting = true;
175 	if (monc->had_a_connection) {
176 		monc->hunt_mult *= CEPH_MONC_HUNT_BACKOFF;
177 		if (monc->hunt_mult > CEPH_MONC_HUNT_MAX_MULT)
178 			monc->hunt_mult = CEPH_MONC_HUNT_MAX_MULT;
179 	}
180 
181 	monc->sub_renew_after = jiffies; /* i.e., expired */
182 	monc->sub_renew_sent = 0;
183 
184 	dout("%s opening mon%d\n", __func__, monc->cur_mon);
185 	ceph_con_open(&monc->con, CEPH_ENTITY_TYPE_MON, monc->cur_mon,
186 		      &monc->monmap->mon_inst[monc->cur_mon].addr);
187 
188 	/*
189 	 * send an initial keepalive to ensure our timestamp is valid
190 	 * by the time we are in an OPENED state
191 	 */
192 	ceph_con_keepalive(&monc->con);
193 
194 	/* initiate authentication handshake */
195 	ret = ceph_auth_build_hello(monc->auth,
196 				    monc->m_auth->front.iov_base,
197 				    monc->m_auth->front_alloc_len);
198 	BUG_ON(ret <= 0);
199 	__send_prepared_auth_request(monc, ret);
200 }
201 
202 static void reopen_session(struct ceph_mon_client *monc)
203 {
204 	if (!monc->hunting)
205 		pr_info("mon%d %s session lost, hunting for new mon\n",
206 		    monc->cur_mon, ceph_pr_addr(&monc->con.peer_addr.in_addr));
207 
208 	__close_session(monc);
209 	__open_session(monc);
210 }
211 
212 /*
213  * Reschedule delayed work timer.
214  */
215 static void __schedule_delayed(struct ceph_mon_client *monc)
216 {
217 	unsigned long delay;
218 
219 	if (monc->hunting)
220 		delay = CEPH_MONC_HUNT_INTERVAL * monc->hunt_mult;
221 	else
222 		delay = CEPH_MONC_PING_INTERVAL;
223 
224 	dout("__schedule_delayed after %lu\n", delay);
225 	mod_delayed_work(system_wq, &monc->delayed_work,
226 			 round_jiffies_relative(delay));
227 }
228 
229 const char *ceph_sub_str[] = {
230 	[CEPH_SUB_MONMAP] = "monmap",
231 	[CEPH_SUB_OSDMAP] = "osdmap",
232 	[CEPH_SUB_FSMAP]  = "fsmap.user",
233 	[CEPH_SUB_MDSMAP] = "mdsmap",
234 };
235 
236 /*
237  * Send subscribe request for one or more maps, according to
238  * monc->subs.
239  */
240 static void __send_subscribe(struct ceph_mon_client *monc)
241 {
242 	struct ceph_msg *msg = monc->m_subscribe;
243 	void *p = msg->front.iov_base;
244 	void *const end = p + msg->front_alloc_len;
245 	int num = 0;
246 	int i;
247 
248 	dout("%s sent %lu\n", __func__, monc->sub_renew_sent);
249 
250 	BUG_ON(monc->cur_mon < 0);
251 
252 	if (!monc->sub_renew_sent)
253 		monc->sub_renew_sent = jiffies | 1; /* never 0 */
254 
255 	msg->hdr.version = cpu_to_le16(2);
256 
257 	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
258 		if (monc->subs[i].want)
259 			num++;
260 	}
261 	BUG_ON(num < 1); /* monmap sub is always there */
262 	ceph_encode_32(&p, num);
263 	for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
264 		char buf[32];
265 		int len;
266 
267 		if (!monc->subs[i].want)
268 			continue;
269 
270 		len = sprintf(buf, "%s", ceph_sub_str[i]);
271 		if (i == CEPH_SUB_MDSMAP &&
272 		    monc->fs_cluster_id != CEPH_FS_CLUSTER_ID_NONE)
273 			len += sprintf(buf + len, ".%d", monc->fs_cluster_id);
274 
275 		dout("%s %s start %llu flags 0x%x\n", __func__, buf,
276 		     le64_to_cpu(monc->subs[i].item.start),
277 		     monc->subs[i].item.flags);
278 		ceph_encode_string(&p, end, buf, len);
279 		memcpy(p, &monc->subs[i].item, sizeof(monc->subs[i].item));
280 		p += sizeof(monc->subs[i].item);
281 	}
282 
283 	BUG_ON(p > end);
284 	msg->front.iov_len = p - msg->front.iov_base;
285 	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
286 	ceph_msg_revoke(msg);
287 	ceph_con_send(&monc->con, ceph_msg_get(msg));
288 }
289 
290 static void handle_subscribe_ack(struct ceph_mon_client *monc,
291 				 struct ceph_msg *msg)
292 {
293 	unsigned int seconds;
294 	struct ceph_mon_subscribe_ack *h = msg->front.iov_base;
295 
296 	if (msg->front.iov_len < sizeof(*h))
297 		goto bad;
298 	seconds = le32_to_cpu(h->duration);
299 
300 	mutex_lock(&monc->mutex);
301 	if (monc->sub_renew_sent) {
302 		/*
303 		 * This is only needed for legacy (infernalis or older)
304 		 * MONs -- see delayed_work().
305 		 */
306 		monc->sub_renew_after = monc->sub_renew_sent +
307 					    (seconds >> 1) * HZ - 1;
308 		dout("%s sent %lu duration %d renew after %lu\n", __func__,
309 		     monc->sub_renew_sent, seconds, monc->sub_renew_after);
310 		monc->sub_renew_sent = 0;
311 	} else {
312 		dout("%s sent %lu renew after %lu, ignoring\n", __func__,
313 		     monc->sub_renew_sent, monc->sub_renew_after);
314 	}
315 	mutex_unlock(&monc->mutex);
316 	return;
317 bad:
318 	pr_err("got corrupt subscribe-ack msg\n");
319 	ceph_msg_dump(msg);
320 }
321 
322 /*
323  * Register interest in a map
324  *
325  * @sub: one of CEPH_SUB_*
326  * @epoch: X for "every map since X", or 0 for "just the latest"
327  */
328 static bool __ceph_monc_want_map(struct ceph_mon_client *monc, int sub,
329 				 u32 epoch, bool continuous)
330 {
331 	__le64 start = cpu_to_le64(epoch);
332 	u8 flags = !continuous ? CEPH_SUBSCRIBE_ONETIME : 0;
333 
334 	dout("%s %s epoch %u continuous %d\n", __func__, ceph_sub_str[sub],
335 	     epoch, continuous);
336 
337 	if (monc->subs[sub].want &&
338 	    monc->subs[sub].item.start == start &&
339 	    monc->subs[sub].item.flags == flags)
340 		return false;
341 
342 	monc->subs[sub].item.start = start;
343 	monc->subs[sub].item.flags = flags;
344 	monc->subs[sub].want = true;
345 
346 	return true;
347 }
348 
349 bool ceph_monc_want_map(struct ceph_mon_client *monc, int sub, u32 epoch,
350 			bool continuous)
351 {
352 	bool need_request;
353 
354 	mutex_lock(&monc->mutex);
355 	need_request = __ceph_monc_want_map(monc, sub, epoch, continuous);
356 	mutex_unlock(&monc->mutex);
357 
358 	return need_request;
359 }
360 EXPORT_SYMBOL(ceph_monc_want_map);
361 
362 /*
363  * Keep track of which maps we have
364  *
365  * @sub: one of CEPH_SUB_*
366  */
367 static void __ceph_monc_got_map(struct ceph_mon_client *monc, int sub,
368 				u32 epoch)
369 {
370 	dout("%s %s epoch %u\n", __func__, ceph_sub_str[sub], epoch);
371 
372 	if (monc->subs[sub].want) {
373 		if (monc->subs[sub].item.flags & CEPH_SUBSCRIBE_ONETIME)
374 			monc->subs[sub].want = false;
375 		else
376 			monc->subs[sub].item.start = cpu_to_le64(epoch + 1);
377 	}
378 
379 	monc->subs[sub].have = epoch;
380 }
381 
382 void ceph_monc_got_map(struct ceph_mon_client *monc, int sub, u32 epoch)
383 {
384 	mutex_lock(&monc->mutex);
385 	__ceph_monc_got_map(monc, sub, epoch);
386 	mutex_unlock(&monc->mutex);
387 }
388 EXPORT_SYMBOL(ceph_monc_got_map);
389 
390 void ceph_monc_renew_subs(struct ceph_mon_client *monc)
391 {
392 	mutex_lock(&monc->mutex);
393 	__send_subscribe(monc);
394 	mutex_unlock(&monc->mutex);
395 }
396 EXPORT_SYMBOL(ceph_monc_renew_subs);
397 
398 /*
399  * Wait for an osdmap with a given epoch.
400  *
401  * @epoch: epoch to wait for
402  * @timeout: in jiffies, 0 means "wait forever"
403  */
404 int ceph_monc_wait_osdmap(struct ceph_mon_client *monc, u32 epoch,
405 			  unsigned long timeout)
406 {
407 	unsigned long started = jiffies;
408 	long ret;
409 
410 	mutex_lock(&monc->mutex);
411 	while (monc->subs[CEPH_SUB_OSDMAP].have < epoch) {
412 		mutex_unlock(&monc->mutex);
413 
414 		if (timeout && time_after_eq(jiffies, started + timeout))
415 			return -ETIMEDOUT;
416 
417 		ret = wait_event_interruptible_timeout(monc->client->auth_wq,
418 				     monc->subs[CEPH_SUB_OSDMAP].have >= epoch,
419 				     ceph_timeout_jiffies(timeout));
420 		if (ret < 0)
421 			return ret;
422 
423 		mutex_lock(&monc->mutex);
424 	}
425 
426 	mutex_unlock(&monc->mutex);
427 	return 0;
428 }
429 EXPORT_SYMBOL(ceph_monc_wait_osdmap);
430 
431 /*
432  * Open a session with a random monitor.  Request monmap and osdmap,
433  * which are waited upon in __ceph_open_session().
434  */
435 int ceph_monc_open_session(struct ceph_mon_client *monc)
436 {
437 	mutex_lock(&monc->mutex);
438 	__ceph_monc_want_map(monc, CEPH_SUB_MONMAP, 0, true);
439 	__ceph_monc_want_map(monc, CEPH_SUB_OSDMAP, 0, false);
440 	__open_session(monc);
441 	__schedule_delayed(monc);
442 	mutex_unlock(&monc->mutex);
443 	return 0;
444 }
445 EXPORT_SYMBOL(ceph_monc_open_session);
446 
447 static void ceph_monc_handle_map(struct ceph_mon_client *monc,
448 				 struct ceph_msg *msg)
449 {
450 	struct ceph_client *client = monc->client;
451 	struct ceph_monmap *monmap = NULL, *old = monc->monmap;
452 	void *p, *end;
453 
454 	mutex_lock(&monc->mutex);
455 
456 	dout("handle_monmap\n");
457 	p = msg->front.iov_base;
458 	end = p + msg->front.iov_len;
459 
460 	monmap = ceph_monmap_decode(p, end);
461 	if (IS_ERR(monmap)) {
462 		pr_err("problem decoding monmap, %d\n",
463 		       (int)PTR_ERR(monmap));
464 		goto out;
465 	}
466 
467 	if (ceph_check_fsid(monc->client, &monmap->fsid) < 0) {
468 		kfree(monmap);
469 		goto out;
470 	}
471 
472 	client->monc.monmap = monmap;
473 	kfree(old);
474 
475 	__ceph_monc_got_map(monc, CEPH_SUB_MONMAP, monc->monmap->epoch);
476 	client->have_fsid = true;
477 
478 out:
479 	mutex_unlock(&monc->mutex);
480 	wake_up_all(&client->auth_wq);
481 }
482 
483 /*
484  * generic requests (currently statfs, mon_get_version)
485  */
486 DEFINE_RB_FUNCS(generic_request, struct ceph_mon_generic_request, tid, node)
487 
488 static void release_generic_request(struct kref *kref)
489 {
490 	struct ceph_mon_generic_request *req =
491 		container_of(kref, struct ceph_mon_generic_request, kref);
492 
493 	dout("%s greq %p request %p reply %p\n", __func__, req, req->request,
494 	     req->reply);
495 	WARN_ON(!RB_EMPTY_NODE(&req->node));
496 
497 	if (req->reply)
498 		ceph_msg_put(req->reply);
499 	if (req->request)
500 		ceph_msg_put(req->request);
501 
502 	kfree(req);
503 }
504 
505 static void put_generic_request(struct ceph_mon_generic_request *req)
506 {
507 	if (req)
508 		kref_put(&req->kref, release_generic_request);
509 }
510 
511 static void get_generic_request(struct ceph_mon_generic_request *req)
512 {
513 	kref_get(&req->kref);
514 }
515 
516 static struct ceph_mon_generic_request *
517 alloc_generic_request(struct ceph_mon_client *monc, gfp_t gfp)
518 {
519 	struct ceph_mon_generic_request *req;
520 
521 	req = kzalloc(sizeof(*req), gfp);
522 	if (!req)
523 		return NULL;
524 
525 	req->monc = monc;
526 	kref_init(&req->kref);
527 	RB_CLEAR_NODE(&req->node);
528 	init_completion(&req->completion);
529 
530 	dout("%s greq %p\n", __func__, req);
531 	return req;
532 }
533 
534 static void register_generic_request(struct ceph_mon_generic_request *req)
535 {
536 	struct ceph_mon_client *monc = req->monc;
537 
538 	WARN_ON(req->tid);
539 
540 	get_generic_request(req);
541 	req->tid = ++monc->last_tid;
542 	insert_generic_request(&monc->generic_request_tree, req);
543 }
544 
545 static void send_generic_request(struct ceph_mon_client *monc,
546 				 struct ceph_mon_generic_request *req)
547 {
548 	WARN_ON(!req->tid);
549 
550 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
551 	req->request->hdr.tid = cpu_to_le64(req->tid);
552 	ceph_con_send(&monc->con, ceph_msg_get(req->request));
553 }
554 
555 static void __finish_generic_request(struct ceph_mon_generic_request *req)
556 {
557 	struct ceph_mon_client *monc = req->monc;
558 
559 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
560 	erase_generic_request(&monc->generic_request_tree, req);
561 
562 	ceph_msg_revoke(req->request);
563 	ceph_msg_revoke_incoming(req->reply);
564 }
565 
566 static void finish_generic_request(struct ceph_mon_generic_request *req)
567 {
568 	__finish_generic_request(req);
569 	put_generic_request(req);
570 }
571 
572 static void complete_generic_request(struct ceph_mon_generic_request *req)
573 {
574 	if (req->complete_cb)
575 		req->complete_cb(req);
576 	else
577 		complete_all(&req->completion);
578 	put_generic_request(req);
579 }
580 
581 static void cancel_generic_request(struct ceph_mon_generic_request *req)
582 {
583 	struct ceph_mon_client *monc = req->monc;
584 	struct ceph_mon_generic_request *lookup_req;
585 
586 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
587 
588 	mutex_lock(&monc->mutex);
589 	lookup_req = lookup_generic_request(&monc->generic_request_tree,
590 					    req->tid);
591 	if (lookup_req) {
592 		WARN_ON(lookup_req != req);
593 		finish_generic_request(req);
594 	}
595 
596 	mutex_unlock(&monc->mutex);
597 }
598 
599 static int wait_generic_request(struct ceph_mon_generic_request *req)
600 {
601 	int ret;
602 
603 	dout("%s greq %p tid %llu\n", __func__, req, req->tid);
604 	ret = wait_for_completion_interruptible(&req->completion);
605 	if (ret)
606 		cancel_generic_request(req);
607 	else
608 		ret = req->result; /* completed */
609 
610 	return ret;
611 }
612 
613 static struct ceph_msg *get_generic_reply(struct ceph_connection *con,
614 					 struct ceph_msg_header *hdr,
615 					 int *skip)
616 {
617 	struct ceph_mon_client *monc = con->private;
618 	struct ceph_mon_generic_request *req;
619 	u64 tid = le64_to_cpu(hdr->tid);
620 	struct ceph_msg *m;
621 
622 	mutex_lock(&monc->mutex);
623 	req = lookup_generic_request(&monc->generic_request_tree, tid);
624 	if (!req) {
625 		dout("get_generic_reply %lld dne\n", tid);
626 		*skip = 1;
627 		m = NULL;
628 	} else {
629 		dout("get_generic_reply %lld got %p\n", tid, req->reply);
630 		*skip = 0;
631 		m = ceph_msg_get(req->reply);
632 		/*
633 		 * we don't need to track the connection reading into
634 		 * this reply because we only have one open connection
635 		 * at a time, ever.
636 		 */
637 	}
638 	mutex_unlock(&monc->mutex);
639 	return m;
640 }
641 
642 /*
643  * statfs
644  */
645 static void handle_statfs_reply(struct ceph_mon_client *monc,
646 				struct ceph_msg *msg)
647 {
648 	struct ceph_mon_generic_request *req;
649 	struct ceph_mon_statfs_reply *reply = msg->front.iov_base;
650 	u64 tid = le64_to_cpu(msg->hdr.tid);
651 
652 	dout("%s msg %p tid %llu\n", __func__, msg, tid);
653 
654 	if (msg->front.iov_len != sizeof(*reply))
655 		goto bad;
656 
657 	mutex_lock(&monc->mutex);
658 	req = lookup_generic_request(&monc->generic_request_tree, tid);
659 	if (!req) {
660 		mutex_unlock(&monc->mutex);
661 		return;
662 	}
663 
664 	req->result = 0;
665 	*req->u.st = reply->st; /* struct */
666 	__finish_generic_request(req);
667 	mutex_unlock(&monc->mutex);
668 
669 	complete_generic_request(req);
670 	return;
671 
672 bad:
673 	pr_err("corrupt statfs reply, tid %llu\n", tid);
674 	ceph_msg_dump(msg);
675 }
676 
677 /*
678  * Do a synchronous statfs().
679  */
680 int ceph_monc_do_statfs(struct ceph_mon_client *monc, u64 data_pool,
681 			struct ceph_statfs *buf)
682 {
683 	struct ceph_mon_generic_request *req;
684 	struct ceph_mon_statfs *h;
685 	int ret = -ENOMEM;
686 
687 	req = alloc_generic_request(monc, GFP_NOFS);
688 	if (!req)
689 		goto out;
690 
691 	req->request = ceph_msg_new(CEPH_MSG_STATFS, sizeof(*h), GFP_NOFS,
692 				    true);
693 	if (!req->request)
694 		goto out;
695 
696 	req->reply = ceph_msg_new(CEPH_MSG_STATFS_REPLY, 64, GFP_NOFS, true);
697 	if (!req->reply)
698 		goto out;
699 
700 	req->u.st = buf;
701 	req->request->hdr.version = cpu_to_le16(2);
702 
703 	mutex_lock(&monc->mutex);
704 	register_generic_request(req);
705 	/* fill out request */
706 	h = req->request->front.iov_base;
707 	h->monhdr.have_version = 0;
708 	h->monhdr.session_mon = cpu_to_le16(-1);
709 	h->monhdr.session_mon_tid = 0;
710 	h->fsid = monc->monmap->fsid;
711 	h->contains_data_pool = (data_pool != CEPH_NOPOOL);
712 	h->data_pool = cpu_to_le64(data_pool);
713 	send_generic_request(monc, req);
714 	mutex_unlock(&monc->mutex);
715 
716 	ret = wait_generic_request(req);
717 out:
718 	put_generic_request(req);
719 	return ret;
720 }
721 EXPORT_SYMBOL(ceph_monc_do_statfs);
722 
723 static void handle_get_version_reply(struct ceph_mon_client *monc,
724 				     struct ceph_msg *msg)
725 {
726 	struct ceph_mon_generic_request *req;
727 	u64 tid = le64_to_cpu(msg->hdr.tid);
728 	void *p = msg->front.iov_base;
729 	void *end = p + msg->front_alloc_len;
730 	u64 handle;
731 
732 	dout("%s msg %p tid %llu\n", __func__, msg, tid);
733 
734 	ceph_decode_need(&p, end, 2*sizeof(u64), bad);
735 	handle = ceph_decode_64(&p);
736 	if (tid != 0 && tid != handle)
737 		goto bad;
738 
739 	mutex_lock(&monc->mutex);
740 	req = lookup_generic_request(&monc->generic_request_tree, handle);
741 	if (!req) {
742 		mutex_unlock(&monc->mutex);
743 		return;
744 	}
745 
746 	req->result = 0;
747 	req->u.newest = ceph_decode_64(&p);
748 	__finish_generic_request(req);
749 	mutex_unlock(&monc->mutex);
750 
751 	complete_generic_request(req);
752 	return;
753 
754 bad:
755 	pr_err("corrupt mon_get_version reply, tid %llu\n", tid);
756 	ceph_msg_dump(msg);
757 }
758 
759 static struct ceph_mon_generic_request *
760 __ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
761 			ceph_monc_callback_t cb, u64 private_data)
762 {
763 	struct ceph_mon_generic_request *req;
764 
765 	req = alloc_generic_request(monc, GFP_NOIO);
766 	if (!req)
767 		goto err_put_req;
768 
769 	req->request = ceph_msg_new(CEPH_MSG_MON_GET_VERSION,
770 				    sizeof(u64) + sizeof(u32) + strlen(what),
771 				    GFP_NOIO, true);
772 	if (!req->request)
773 		goto err_put_req;
774 
775 	req->reply = ceph_msg_new(CEPH_MSG_MON_GET_VERSION_REPLY, 32, GFP_NOIO,
776 				  true);
777 	if (!req->reply)
778 		goto err_put_req;
779 
780 	req->complete_cb = cb;
781 	req->private_data = private_data;
782 
783 	mutex_lock(&monc->mutex);
784 	register_generic_request(req);
785 	{
786 		void *p = req->request->front.iov_base;
787 		void *const end = p + req->request->front_alloc_len;
788 
789 		ceph_encode_64(&p, req->tid); /* handle */
790 		ceph_encode_string(&p, end, what, strlen(what));
791 		WARN_ON(p != end);
792 	}
793 	send_generic_request(monc, req);
794 	mutex_unlock(&monc->mutex);
795 
796 	return req;
797 
798 err_put_req:
799 	put_generic_request(req);
800 	return ERR_PTR(-ENOMEM);
801 }
802 
803 /*
804  * Send MMonGetVersion and wait for the reply.
805  *
806  * @what: one of "mdsmap", "osdmap" or "monmap"
807  */
808 int ceph_monc_get_version(struct ceph_mon_client *monc, const char *what,
809 			  u64 *newest)
810 {
811 	struct ceph_mon_generic_request *req;
812 	int ret;
813 
814 	req = __ceph_monc_get_version(monc, what, NULL, 0);
815 	if (IS_ERR(req))
816 		return PTR_ERR(req);
817 
818 	ret = wait_generic_request(req);
819 	if (!ret)
820 		*newest = req->u.newest;
821 
822 	put_generic_request(req);
823 	return ret;
824 }
825 EXPORT_SYMBOL(ceph_monc_get_version);
826 
827 /*
828  * Send MMonGetVersion,
829  *
830  * @what: one of "mdsmap", "osdmap" or "monmap"
831  */
832 int ceph_monc_get_version_async(struct ceph_mon_client *monc, const char *what,
833 				ceph_monc_callback_t cb, u64 private_data)
834 {
835 	struct ceph_mon_generic_request *req;
836 
837 	req = __ceph_monc_get_version(monc, what, cb, private_data);
838 	if (IS_ERR(req))
839 		return PTR_ERR(req);
840 
841 	put_generic_request(req);
842 	return 0;
843 }
844 EXPORT_SYMBOL(ceph_monc_get_version_async);
845 
846 static void handle_command_ack(struct ceph_mon_client *monc,
847 			       struct ceph_msg *msg)
848 {
849 	struct ceph_mon_generic_request *req;
850 	void *p = msg->front.iov_base;
851 	void *const end = p + msg->front_alloc_len;
852 	u64 tid = le64_to_cpu(msg->hdr.tid);
853 
854 	dout("%s msg %p tid %llu\n", __func__, msg, tid);
855 
856 	ceph_decode_need(&p, end, sizeof(struct ceph_mon_request_header) +
857 							    sizeof(u32), bad);
858 	p += sizeof(struct ceph_mon_request_header);
859 
860 	mutex_lock(&monc->mutex);
861 	req = lookup_generic_request(&monc->generic_request_tree, tid);
862 	if (!req) {
863 		mutex_unlock(&monc->mutex);
864 		return;
865 	}
866 
867 	req->result = ceph_decode_32(&p);
868 	__finish_generic_request(req);
869 	mutex_unlock(&monc->mutex);
870 
871 	complete_generic_request(req);
872 	return;
873 
874 bad:
875 	pr_err("corrupt mon_command ack, tid %llu\n", tid);
876 	ceph_msg_dump(msg);
877 }
878 
879 int ceph_monc_blacklist_add(struct ceph_mon_client *monc,
880 			    struct ceph_entity_addr *client_addr)
881 {
882 	struct ceph_mon_generic_request *req;
883 	struct ceph_mon_command *h;
884 	int ret = -ENOMEM;
885 	int len;
886 
887 	req = alloc_generic_request(monc, GFP_NOIO);
888 	if (!req)
889 		goto out;
890 
891 	req->request = ceph_msg_new(CEPH_MSG_MON_COMMAND, 256, GFP_NOIO, true);
892 	if (!req->request)
893 		goto out;
894 
895 	req->reply = ceph_msg_new(CEPH_MSG_MON_COMMAND_ACK, 512, GFP_NOIO,
896 				  true);
897 	if (!req->reply)
898 		goto out;
899 
900 	mutex_lock(&monc->mutex);
901 	register_generic_request(req);
902 	h = req->request->front.iov_base;
903 	h->monhdr.have_version = 0;
904 	h->monhdr.session_mon = cpu_to_le16(-1);
905 	h->monhdr.session_mon_tid = 0;
906 	h->fsid = monc->monmap->fsid;
907 	h->num_strs = cpu_to_le32(1);
908 	len = sprintf(h->str, "{ \"prefix\": \"osd blacklist\", \
909 		                 \"blacklistop\": \"add\", \
910 				 \"addr\": \"%pISpc/%u\" }",
911 		      &client_addr->in_addr, le32_to_cpu(client_addr->nonce));
912 	h->str_len = cpu_to_le32(len);
913 	send_generic_request(monc, req);
914 	mutex_unlock(&monc->mutex);
915 
916 	ret = wait_generic_request(req);
917 out:
918 	put_generic_request(req);
919 	return ret;
920 }
921 EXPORT_SYMBOL(ceph_monc_blacklist_add);
922 
923 /*
924  * Resend pending generic requests.
925  */
926 static void __resend_generic_request(struct ceph_mon_client *monc)
927 {
928 	struct ceph_mon_generic_request *req;
929 	struct rb_node *p;
930 
931 	for (p = rb_first(&monc->generic_request_tree); p; p = rb_next(p)) {
932 		req = rb_entry(p, struct ceph_mon_generic_request, node);
933 		ceph_msg_revoke(req->request);
934 		ceph_msg_revoke_incoming(req->reply);
935 		ceph_con_send(&monc->con, ceph_msg_get(req->request));
936 	}
937 }
938 
939 /*
940  * Delayed work.  If we haven't mounted yet, retry.  Otherwise,
941  * renew/retry subscription as needed (in case it is timing out, or we
942  * got an ENOMEM).  And keep the monitor connection alive.
943  */
944 static void delayed_work(struct work_struct *work)
945 {
946 	struct ceph_mon_client *monc =
947 		container_of(work, struct ceph_mon_client, delayed_work.work);
948 
949 	dout("monc delayed_work\n");
950 	mutex_lock(&monc->mutex);
951 	if (monc->hunting) {
952 		dout("%s continuing hunt\n", __func__);
953 		reopen_session(monc);
954 	} else {
955 		int is_auth = ceph_auth_is_authenticated(monc->auth);
956 		if (ceph_con_keepalive_expired(&monc->con,
957 					       CEPH_MONC_PING_TIMEOUT)) {
958 			dout("monc keepalive timeout\n");
959 			is_auth = 0;
960 			reopen_session(monc);
961 		}
962 
963 		if (!monc->hunting) {
964 			ceph_con_keepalive(&monc->con);
965 			__validate_auth(monc);
966 		}
967 
968 		if (is_auth &&
969 		    !(monc->con.peer_features & CEPH_FEATURE_MON_STATEFUL_SUB)) {
970 			unsigned long now = jiffies;
971 
972 			dout("%s renew subs? now %lu renew after %lu\n",
973 			     __func__, now, monc->sub_renew_after);
974 			if (time_after_eq(now, monc->sub_renew_after))
975 				__send_subscribe(monc);
976 		}
977 	}
978 	__schedule_delayed(monc);
979 	mutex_unlock(&monc->mutex);
980 }
981 
982 /*
983  * On startup, we build a temporary monmap populated with the IPs
984  * provided by mount(2).
985  */
986 static int build_initial_monmap(struct ceph_mon_client *monc)
987 {
988 	struct ceph_options *opt = monc->client->options;
989 	struct ceph_entity_addr *mon_addr = opt->mon_addr;
990 	int num_mon = opt->num_mon;
991 	int i;
992 
993 	/* build initial monmap */
994 	monc->monmap = kzalloc(sizeof(*monc->monmap) +
995 			       num_mon*sizeof(monc->monmap->mon_inst[0]),
996 			       GFP_KERNEL);
997 	if (!monc->monmap)
998 		return -ENOMEM;
999 	for (i = 0; i < num_mon; i++) {
1000 		monc->monmap->mon_inst[i].addr = mon_addr[i];
1001 		monc->monmap->mon_inst[i].addr.nonce = 0;
1002 		monc->monmap->mon_inst[i].name.type =
1003 			CEPH_ENTITY_TYPE_MON;
1004 		monc->monmap->mon_inst[i].name.num = cpu_to_le64(i);
1005 	}
1006 	monc->monmap->num_mon = num_mon;
1007 	return 0;
1008 }
1009 
1010 int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
1011 {
1012 	int err = 0;
1013 
1014 	dout("init\n");
1015 	memset(monc, 0, sizeof(*monc));
1016 	monc->client = cl;
1017 	monc->monmap = NULL;
1018 	mutex_init(&monc->mutex);
1019 
1020 	err = build_initial_monmap(monc);
1021 	if (err)
1022 		goto out;
1023 
1024 	/* connection */
1025 	/* authentication */
1026 	monc->auth = ceph_auth_init(cl->options->name,
1027 				    cl->options->key);
1028 	if (IS_ERR(monc->auth)) {
1029 		err = PTR_ERR(monc->auth);
1030 		goto out_monmap;
1031 	}
1032 	monc->auth->want_keys =
1033 		CEPH_ENTITY_TYPE_AUTH | CEPH_ENTITY_TYPE_MON |
1034 		CEPH_ENTITY_TYPE_OSD | CEPH_ENTITY_TYPE_MDS;
1035 
1036 	/* msgs */
1037 	err = -ENOMEM;
1038 	monc->m_subscribe_ack = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE_ACK,
1039 				     sizeof(struct ceph_mon_subscribe_ack),
1040 				     GFP_KERNEL, true);
1041 	if (!monc->m_subscribe_ack)
1042 		goto out_auth;
1043 
1044 	monc->m_subscribe = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 128,
1045 					 GFP_KERNEL, true);
1046 	if (!monc->m_subscribe)
1047 		goto out_subscribe_ack;
1048 
1049 	monc->m_auth_reply = ceph_msg_new(CEPH_MSG_AUTH_REPLY, 4096,
1050 					  GFP_KERNEL, true);
1051 	if (!monc->m_auth_reply)
1052 		goto out_subscribe;
1053 
1054 	monc->m_auth = ceph_msg_new(CEPH_MSG_AUTH, 4096, GFP_KERNEL, true);
1055 	monc->pending_auth = 0;
1056 	if (!monc->m_auth)
1057 		goto out_auth_reply;
1058 
1059 	ceph_con_init(&monc->con, monc, &mon_con_ops,
1060 		      &monc->client->msgr);
1061 
1062 	monc->cur_mon = -1;
1063 	monc->had_a_connection = false;
1064 	monc->hunt_mult = 1;
1065 
1066 	INIT_DELAYED_WORK(&monc->delayed_work, delayed_work);
1067 	monc->generic_request_tree = RB_ROOT;
1068 	monc->last_tid = 0;
1069 
1070 	monc->fs_cluster_id = CEPH_FS_CLUSTER_ID_NONE;
1071 
1072 	return 0;
1073 
1074 out_auth_reply:
1075 	ceph_msg_put(monc->m_auth_reply);
1076 out_subscribe:
1077 	ceph_msg_put(monc->m_subscribe);
1078 out_subscribe_ack:
1079 	ceph_msg_put(monc->m_subscribe_ack);
1080 out_auth:
1081 	ceph_auth_destroy(monc->auth);
1082 out_monmap:
1083 	kfree(monc->monmap);
1084 out:
1085 	return err;
1086 }
1087 EXPORT_SYMBOL(ceph_monc_init);
1088 
1089 void ceph_monc_stop(struct ceph_mon_client *monc)
1090 {
1091 	dout("stop\n");
1092 	cancel_delayed_work_sync(&monc->delayed_work);
1093 
1094 	mutex_lock(&monc->mutex);
1095 	__close_session(monc);
1096 	monc->cur_mon = -1;
1097 	mutex_unlock(&monc->mutex);
1098 
1099 	/*
1100 	 * flush msgr queue before we destroy ourselves to ensure that:
1101 	 *  - any work that references our embedded con is finished.
1102 	 *  - any osd_client or other work that may reference an authorizer
1103 	 *    finishes before we shut down the auth subsystem.
1104 	 */
1105 	ceph_msgr_flush();
1106 
1107 	ceph_auth_destroy(monc->auth);
1108 
1109 	WARN_ON(!RB_EMPTY_ROOT(&monc->generic_request_tree));
1110 
1111 	ceph_msg_put(monc->m_auth);
1112 	ceph_msg_put(monc->m_auth_reply);
1113 	ceph_msg_put(monc->m_subscribe);
1114 	ceph_msg_put(monc->m_subscribe_ack);
1115 
1116 	kfree(monc->monmap);
1117 }
1118 EXPORT_SYMBOL(ceph_monc_stop);
1119 
1120 static void finish_hunting(struct ceph_mon_client *monc)
1121 {
1122 	if (monc->hunting) {
1123 		dout("%s found mon%d\n", __func__, monc->cur_mon);
1124 		monc->hunting = false;
1125 		monc->had_a_connection = true;
1126 		monc->hunt_mult /= 2; /* reduce by 50% */
1127 		if (monc->hunt_mult < 1)
1128 			monc->hunt_mult = 1;
1129 	}
1130 }
1131 
1132 static void handle_auth_reply(struct ceph_mon_client *monc,
1133 			      struct ceph_msg *msg)
1134 {
1135 	int ret;
1136 	int was_auth = 0;
1137 
1138 	mutex_lock(&monc->mutex);
1139 	was_auth = ceph_auth_is_authenticated(monc->auth);
1140 	monc->pending_auth = 0;
1141 	ret = ceph_handle_auth_reply(monc->auth, msg->front.iov_base,
1142 				     msg->front.iov_len,
1143 				     monc->m_auth->front.iov_base,
1144 				     monc->m_auth->front_alloc_len);
1145 	if (ret > 0) {
1146 		__send_prepared_auth_request(monc, ret);
1147 		goto out;
1148 	}
1149 
1150 	finish_hunting(monc);
1151 
1152 	if (ret < 0) {
1153 		monc->client->auth_err = ret;
1154 	} else if (!was_auth && ceph_auth_is_authenticated(monc->auth)) {
1155 		dout("authenticated, starting session\n");
1156 
1157 		monc->client->msgr.inst.name.type = CEPH_ENTITY_TYPE_CLIENT;
1158 		monc->client->msgr.inst.name.num =
1159 					cpu_to_le64(monc->auth->global_id);
1160 
1161 		__send_subscribe(monc);
1162 		__resend_generic_request(monc);
1163 
1164 		pr_info("mon%d %s session established\n", monc->cur_mon,
1165 			ceph_pr_addr(&monc->con.peer_addr.in_addr));
1166 	}
1167 
1168 out:
1169 	mutex_unlock(&monc->mutex);
1170 	if (monc->client->auth_err < 0)
1171 		wake_up_all(&monc->client->auth_wq);
1172 }
1173 
1174 static int __validate_auth(struct ceph_mon_client *monc)
1175 {
1176 	int ret;
1177 
1178 	if (monc->pending_auth)
1179 		return 0;
1180 
1181 	ret = ceph_build_auth(monc->auth, monc->m_auth->front.iov_base,
1182 			      monc->m_auth->front_alloc_len);
1183 	if (ret <= 0)
1184 		return ret; /* either an error, or no need to authenticate */
1185 	__send_prepared_auth_request(monc, ret);
1186 	return 0;
1187 }
1188 
1189 int ceph_monc_validate_auth(struct ceph_mon_client *monc)
1190 {
1191 	int ret;
1192 
1193 	mutex_lock(&monc->mutex);
1194 	ret = __validate_auth(monc);
1195 	mutex_unlock(&monc->mutex);
1196 	return ret;
1197 }
1198 EXPORT_SYMBOL(ceph_monc_validate_auth);
1199 
1200 /*
1201  * handle incoming message
1202  */
1203 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
1204 {
1205 	struct ceph_mon_client *monc = con->private;
1206 	int type = le16_to_cpu(msg->hdr.type);
1207 
1208 	if (!monc)
1209 		return;
1210 
1211 	switch (type) {
1212 	case CEPH_MSG_AUTH_REPLY:
1213 		handle_auth_reply(monc, msg);
1214 		break;
1215 
1216 	case CEPH_MSG_MON_SUBSCRIBE_ACK:
1217 		handle_subscribe_ack(monc, msg);
1218 		break;
1219 
1220 	case CEPH_MSG_STATFS_REPLY:
1221 		handle_statfs_reply(monc, msg);
1222 		break;
1223 
1224 	case CEPH_MSG_MON_GET_VERSION_REPLY:
1225 		handle_get_version_reply(monc, msg);
1226 		break;
1227 
1228 	case CEPH_MSG_MON_COMMAND_ACK:
1229 		handle_command_ack(monc, msg);
1230 		break;
1231 
1232 	case CEPH_MSG_MON_MAP:
1233 		ceph_monc_handle_map(monc, msg);
1234 		break;
1235 
1236 	case CEPH_MSG_OSD_MAP:
1237 		ceph_osdc_handle_map(&monc->client->osdc, msg);
1238 		break;
1239 
1240 	default:
1241 		/* can the chained handler handle it? */
1242 		if (monc->client->extra_mon_dispatch &&
1243 		    monc->client->extra_mon_dispatch(monc->client, msg) == 0)
1244 			break;
1245 
1246 		pr_err("received unknown message type %d %s\n", type,
1247 		       ceph_msg_type_name(type));
1248 	}
1249 	ceph_msg_put(msg);
1250 }
1251 
1252 /*
1253  * Allocate memory for incoming message
1254  */
1255 static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
1256 				      struct ceph_msg_header *hdr,
1257 				      int *skip)
1258 {
1259 	struct ceph_mon_client *monc = con->private;
1260 	int type = le16_to_cpu(hdr->type);
1261 	int front_len = le32_to_cpu(hdr->front_len);
1262 	struct ceph_msg *m = NULL;
1263 
1264 	*skip = 0;
1265 
1266 	switch (type) {
1267 	case CEPH_MSG_MON_SUBSCRIBE_ACK:
1268 		m = ceph_msg_get(monc->m_subscribe_ack);
1269 		break;
1270 	case CEPH_MSG_STATFS_REPLY:
1271 	case CEPH_MSG_MON_COMMAND_ACK:
1272 		return get_generic_reply(con, hdr, skip);
1273 	case CEPH_MSG_AUTH_REPLY:
1274 		m = ceph_msg_get(monc->m_auth_reply);
1275 		break;
1276 	case CEPH_MSG_MON_GET_VERSION_REPLY:
1277 		if (le64_to_cpu(hdr->tid) != 0)
1278 			return get_generic_reply(con, hdr, skip);
1279 
1280 		/*
1281 		 * Older OSDs don't set reply tid even if the orignal
1282 		 * request had a non-zero tid.  Work around this weirdness
1283 		 * by allocating a new message.
1284 		 */
1285 		/* fall through */
1286 	case CEPH_MSG_MON_MAP:
1287 	case CEPH_MSG_MDS_MAP:
1288 	case CEPH_MSG_OSD_MAP:
1289 	case CEPH_MSG_FS_MAP_USER:
1290 		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
1291 		if (!m)
1292 			return NULL;	/* ENOMEM--return skip == 0 */
1293 		break;
1294 	}
1295 
1296 	if (!m) {
1297 		pr_info("alloc_msg unknown type %d\n", type);
1298 		*skip = 1;
1299 	} else if (front_len > m->front_alloc_len) {
1300 		pr_warn("mon_alloc_msg front %d > prealloc %d (%u#%llu)\n",
1301 			front_len, m->front_alloc_len,
1302 			(unsigned int)con->peer_name.type,
1303 			le64_to_cpu(con->peer_name.num));
1304 		ceph_msg_put(m);
1305 		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
1306 	}
1307 
1308 	return m;
1309 }
1310 
1311 /*
1312  * If the monitor connection resets, pick a new monitor and resubmit
1313  * any pending requests.
1314  */
1315 static void mon_fault(struct ceph_connection *con)
1316 {
1317 	struct ceph_mon_client *monc = con->private;
1318 
1319 	mutex_lock(&monc->mutex);
1320 	dout("%s mon%d\n", __func__, monc->cur_mon);
1321 	if (monc->cur_mon >= 0) {
1322 		if (!monc->hunting) {
1323 			dout("%s hunting for new mon\n", __func__);
1324 			reopen_session(monc);
1325 			__schedule_delayed(monc);
1326 		} else {
1327 			dout("%s already hunting\n", __func__);
1328 		}
1329 	}
1330 	mutex_unlock(&monc->mutex);
1331 }
1332 
1333 /*
1334  * We can ignore refcounting on the connection struct, as all references
1335  * will come from the messenger workqueue, which is drained prior to
1336  * mon_client destruction.
1337  */
1338 static struct ceph_connection *con_get(struct ceph_connection *con)
1339 {
1340 	return con;
1341 }
1342 
1343 static void con_put(struct ceph_connection *con)
1344 {
1345 }
1346 
1347 static const struct ceph_connection_operations mon_con_ops = {
1348 	.get = con_get,
1349 	.put = con_put,
1350 	.dispatch = dispatch,
1351 	.fault = mon_fault,
1352 	.alloc_msg = mon_alloc_msg,
1353 };
1354