mon_client.c revision 6740a845b2543cc46e1902ba21bac743fbadd0dc
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/mon_client.h>
10#include <linux/ceph/libceph.h>
11#include <linux/ceph/debugfs.h>
12#include <linux/ceph/decode.h>
13#include <linux/ceph/auth.h>
14
15/*
16 * Interact with Ceph monitor cluster.  Handle requests for new map
17 * versions, and periodically resend as needed.  Also implement
18 * statfs() and umount().
19 *
20 * A small cluster of Ceph "monitors" are responsible for managing critical
21 * cluster configuration and state information.  An odd number (e.g., 3, 5)
22 * of cmon daemons use a modified version of the Paxos part-time parliament
23 * algorithm to manage the MDS map (mds cluster membership), OSD map, and
24 * list of clients who have mounted the file system.
25 *
26 * We maintain an open, active session with a monitor at all times in order to
27 * receive timely MDSMap updates.  We periodically send a keepalive byte on the
28 * TCP socket to ensure we detect a failure.  If the connection does break, we
29 * randomly hunt for a new monitor.  Once the connection is reestablished, we
30 * resend any outstanding requests.
31 */
32
33static const struct ceph_connection_operations mon_con_ops;
34
35static int __validate_auth(struct ceph_mon_client *monc);
36
37/*
38 * Decode a monmap blob (e.g., during mount).
39 */
40struct ceph_monmap *ceph_monmap_decode(void *p, void *end)
41{
42	struct ceph_monmap *m = NULL;
43	int i, err = -EINVAL;
44	struct ceph_fsid fsid;
45	u32 epoch, num_mon;
46	u16 version;
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
54	ceph_decode_16_safe(&p, end, version, bad);
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
82bad:
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 */
91int 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 */
104static 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 */
117static 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_con_close(&monc->con);
122	monc->con.private = NULL;
123	monc->cur_mon = -1;
124	monc->pending_auth = 0;
125	ceph_auth_reset(monc->auth);
126}
127
128/*
129 * Open a session with a (new) monitor.
130 */
131static int __open_session(struct ceph_mon_client *monc)
132{
133	char r;
134	int ret;
135
136	if (monc->cur_mon < 0) {
137		get_random_bytes(&r, 1);
138		monc->cur_mon = r % monc->monmap->num_mon;
139		dout("open_session num=%d r=%d -> mon%d\n",
140		     monc->monmap->num_mon, r, monc->cur_mon);
141		monc->sub_sent = 0;
142		monc->sub_renew_after = jiffies;  /* i.e., expired */
143		monc->want_next_osdmap = !!monc->want_next_osdmap;
144
145		ceph_con_init(&monc->con, monc, &mon_con_ops,
146			&monc->client->msgr,
147			CEPH_ENTITY_TYPE_MON, monc->cur_mon);
148
149		dout("open_session mon%d opening\n", monc->cur_mon);
150		ceph_con_open(&monc->con,
151			      &monc->monmap->mon_inst[monc->cur_mon].addr);
152
153		/* initiatiate authentication handshake */
154		ret = ceph_auth_build_hello(monc->auth,
155					    monc->m_auth->front.iov_base,
156					    monc->m_auth->front_max);
157		__send_prepared_auth_request(monc, ret);
158	} else {
159		dout("open_session mon%d already open\n", monc->cur_mon);
160	}
161	return 0;
162}
163
164static bool __sub_expired(struct ceph_mon_client *monc)
165{
166	return time_after_eq(jiffies, monc->sub_renew_after);
167}
168
169/*
170 * Reschedule delayed work timer.
171 */
172static void __schedule_delayed(struct ceph_mon_client *monc)
173{
174	unsigned delay;
175
176	if (monc->cur_mon < 0 || __sub_expired(monc))
177		delay = 10 * HZ;
178	else
179		delay = 20 * HZ;
180	dout("__schedule_delayed after %u\n", delay);
181	schedule_delayed_work(&monc->delayed_work, delay);
182}
183
184/*
185 * Send subscribe request for mdsmap and/or osdmap.
186 */
187static void __send_subscribe(struct ceph_mon_client *monc)
188{
189	dout("__send_subscribe sub_sent=%u exp=%u want_osd=%d\n",
190	     (unsigned)monc->sub_sent, __sub_expired(monc),
191	     monc->want_next_osdmap);
192	if ((__sub_expired(monc) && !monc->sub_sent) ||
193	    monc->want_next_osdmap == 1) {
194		struct ceph_msg *msg = monc->m_subscribe;
195		struct ceph_mon_subscribe_item *i;
196		void *p, *end;
197		int num;
198
199		p = msg->front.iov_base;
200		end = p + msg->front_max;
201
202		num = 1 + !!monc->want_next_osdmap + !!monc->want_mdsmap;
203		ceph_encode_32(&p, num);
204
205		if (monc->want_next_osdmap) {
206			dout("__send_subscribe to 'osdmap' %u\n",
207			     (unsigned)monc->have_osdmap);
208			ceph_encode_string(&p, end, "osdmap", 6);
209			i = p;
210			i->have = cpu_to_le64(monc->have_osdmap);
211			i->onetime = 1;
212			p += sizeof(*i);
213			monc->want_next_osdmap = 2;  /* requested */
214		}
215		if (monc->want_mdsmap) {
216			dout("__send_subscribe to 'mdsmap' %u+\n",
217			     (unsigned)monc->have_mdsmap);
218			ceph_encode_string(&p, end, "mdsmap", 6);
219			i = p;
220			i->have = cpu_to_le64(monc->have_mdsmap);
221			i->onetime = 0;
222			p += sizeof(*i);
223		}
224		ceph_encode_string(&p, end, "monmap", 6);
225		i = p;
226		i->have = 0;
227		i->onetime = 0;
228		p += sizeof(*i);
229
230		msg->front.iov_len = p - msg->front.iov_base;
231		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
232		ceph_msg_revoke(msg);
233		ceph_con_send(&monc->con, ceph_msg_get(msg));
234
235		monc->sub_sent = jiffies | 1;  /* never 0 */
236	}
237}
238
239static void handle_subscribe_ack(struct ceph_mon_client *monc,
240				 struct ceph_msg *msg)
241{
242	unsigned seconds;
243	struct ceph_mon_subscribe_ack *h = msg->front.iov_base;
244
245	if (msg->front.iov_len < sizeof(*h))
246		goto bad;
247	seconds = le32_to_cpu(h->duration);
248
249	mutex_lock(&monc->mutex);
250	if (monc->hunting) {
251		pr_info("mon%d %s session established\n",
252			monc->cur_mon,
253			ceph_pr_addr(&monc->con.peer_addr.in_addr));
254		monc->hunting = false;
255	}
256	dout("handle_subscribe_ack after %d seconds\n", seconds);
257	monc->sub_renew_after = monc->sub_sent + (seconds >> 1)*HZ - 1;
258	monc->sub_sent = 0;
259	mutex_unlock(&monc->mutex);
260	return;
261bad:
262	pr_err("got corrupt subscribe-ack msg\n");
263	ceph_msg_dump(msg);
264}
265
266/*
267 * Keep track of which maps we have
268 */
269int ceph_monc_got_mdsmap(struct ceph_mon_client *monc, u32 got)
270{
271	mutex_lock(&monc->mutex);
272	monc->have_mdsmap = got;
273	mutex_unlock(&monc->mutex);
274	return 0;
275}
276EXPORT_SYMBOL(ceph_monc_got_mdsmap);
277
278int ceph_monc_got_osdmap(struct ceph_mon_client *monc, u32 got)
279{
280	mutex_lock(&monc->mutex);
281	monc->have_osdmap = got;
282	monc->want_next_osdmap = 0;
283	mutex_unlock(&monc->mutex);
284	return 0;
285}
286
287/*
288 * Register interest in the next osdmap
289 */
290void ceph_monc_request_next_osdmap(struct ceph_mon_client *monc)
291{
292	dout("request_next_osdmap have %u\n", monc->have_osdmap);
293	mutex_lock(&monc->mutex);
294	if (!monc->want_next_osdmap)
295		monc->want_next_osdmap = 1;
296	if (monc->want_next_osdmap < 2)
297		__send_subscribe(monc);
298	mutex_unlock(&monc->mutex);
299}
300
301/*
302 *
303 */
304int ceph_monc_open_session(struct ceph_mon_client *monc)
305{
306	mutex_lock(&monc->mutex);
307	__open_session(monc);
308	__schedule_delayed(monc);
309	mutex_unlock(&monc->mutex);
310	return 0;
311}
312EXPORT_SYMBOL(ceph_monc_open_session);
313
314/*
315 * The monitor responds with mount ack indicate mount success.  The
316 * included client ticket allows the client to talk to MDSs and OSDs.
317 */
318static void ceph_monc_handle_map(struct ceph_mon_client *monc,
319				 struct ceph_msg *msg)
320{
321	struct ceph_client *client = monc->client;
322	struct ceph_monmap *monmap = NULL, *old = monc->monmap;
323	void *p, *end;
324
325	mutex_lock(&monc->mutex);
326
327	dout("handle_monmap\n");
328	p = msg->front.iov_base;
329	end = p + msg->front.iov_len;
330
331	monmap = ceph_monmap_decode(p, end);
332	if (IS_ERR(monmap)) {
333		pr_err("problem decoding monmap, %d\n",
334		       (int)PTR_ERR(monmap));
335		goto out;
336	}
337
338	if (ceph_check_fsid(monc->client, &monmap->fsid) < 0) {
339		kfree(monmap);
340		goto out;
341	}
342
343	client->monc.monmap = monmap;
344	kfree(old);
345
346	if (!client->have_fsid) {
347		client->have_fsid = true;
348		mutex_unlock(&monc->mutex);
349		/*
350		 * do debugfs initialization without mutex to avoid
351		 * creating a locking dependency
352		 */
353		ceph_debugfs_client_init(client);
354		goto out_unlocked;
355	}
356out:
357	mutex_unlock(&monc->mutex);
358out_unlocked:
359	wake_up_all(&client->auth_wq);
360}
361
362/*
363 * generic requests (e.g., statfs, poolop)
364 */
365static struct ceph_mon_generic_request *__lookup_generic_req(
366	struct ceph_mon_client *monc, u64 tid)
367{
368	struct ceph_mon_generic_request *req;
369	struct rb_node *n = monc->generic_request_tree.rb_node;
370
371	while (n) {
372		req = rb_entry(n, struct ceph_mon_generic_request, node);
373		if (tid < req->tid)
374			n = n->rb_left;
375		else if (tid > req->tid)
376			n = n->rb_right;
377		else
378			return req;
379	}
380	return NULL;
381}
382
383static void __insert_generic_request(struct ceph_mon_client *monc,
384			    struct ceph_mon_generic_request *new)
385{
386	struct rb_node **p = &monc->generic_request_tree.rb_node;
387	struct rb_node *parent = NULL;
388	struct ceph_mon_generic_request *req = NULL;
389
390	while (*p) {
391		parent = *p;
392		req = rb_entry(parent, struct ceph_mon_generic_request, node);
393		if (new->tid < req->tid)
394			p = &(*p)->rb_left;
395		else if (new->tid > req->tid)
396			p = &(*p)->rb_right;
397		else
398			BUG();
399	}
400
401	rb_link_node(&new->node, parent, p);
402	rb_insert_color(&new->node, &monc->generic_request_tree);
403}
404
405static void release_generic_request(struct kref *kref)
406{
407	struct ceph_mon_generic_request *req =
408		container_of(kref, struct ceph_mon_generic_request, kref);
409
410	if (req->reply)
411		ceph_msg_put(req->reply);
412	if (req->request)
413		ceph_msg_put(req->request);
414
415	kfree(req);
416}
417
418static void put_generic_request(struct ceph_mon_generic_request *req)
419{
420	kref_put(&req->kref, release_generic_request);
421}
422
423static void get_generic_request(struct ceph_mon_generic_request *req)
424{
425	kref_get(&req->kref);
426}
427
428static struct ceph_msg *get_generic_reply(struct ceph_connection *con,
429					 struct ceph_msg_header *hdr,
430					 int *skip)
431{
432	struct ceph_mon_client *monc = con->private;
433	struct ceph_mon_generic_request *req;
434	u64 tid = le64_to_cpu(hdr->tid);
435	struct ceph_msg *m;
436
437	mutex_lock(&monc->mutex);
438	req = __lookup_generic_req(monc, tid);
439	if (!req) {
440		dout("get_generic_reply %lld dne\n", tid);
441		*skip = 1;
442		m = NULL;
443	} else {
444		dout("get_generic_reply %lld got %p\n", tid, req->reply);
445		*skip = 0;
446		m = ceph_msg_get(req->reply);
447		/*
448		 * we don't need to track the connection reading into
449		 * this reply because we only have one open connection
450		 * at a time, ever.
451		 */
452	}
453	mutex_unlock(&monc->mutex);
454	return m;
455}
456
457static int do_generic_request(struct ceph_mon_client *monc,
458			      struct ceph_mon_generic_request *req)
459{
460	int err;
461
462	/* register request */
463	mutex_lock(&monc->mutex);
464	req->tid = ++monc->last_tid;
465	req->request->hdr.tid = cpu_to_le64(req->tid);
466	__insert_generic_request(monc, req);
467	monc->num_generic_requests++;
468	ceph_con_send(&monc->con, ceph_msg_get(req->request));
469	mutex_unlock(&monc->mutex);
470
471	err = wait_for_completion_interruptible(&req->completion);
472
473	mutex_lock(&monc->mutex);
474	rb_erase(&req->node, &monc->generic_request_tree);
475	monc->num_generic_requests--;
476	mutex_unlock(&monc->mutex);
477
478	if (!err)
479		err = req->result;
480	return err;
481}
482
483/*
484 * statfs
485 */
486static void handle_statfs_reply(struct ceph_mon_client *monc,
487				struct ceph_msg *msg)
488{
489	struct ceph_mon_generic_request *req;
490	struct ceph_mon_statfs_reply *reply = msg->front.iov_base;
491	u64 tid = le64_to_cpu(msg->hdr.tid);
492
493	if (msg->front.iov_len != sizeof(*reply))
494		goto bad;
495	dout("handle_statfs_reply %p tid %llu\n", msg, tid);
496
497	mutex_lock(&monc->mutex);
498	req = __lookup_generic_req(monc, tid);
499	if (req) {
500		*(struct ceph_statfs *)req->buf = reply->st;
501		req->result = 0;
502		get_generic_request(req);
503	}
504	mutex_unlock(&monc->mutex);
505	if (req) {
506		complete_all(&req->completion);
507		put_generic_request(req);
508	}
509	return;
510
511bad:
512	pr_err("corrupt generic reply, tid %llu\n", tid);
513	ceph_msg_dump(msg);
514}
515
516/*
517 * Do a synchronous statfs().
518 */
519int ceph_monc_do_statfs(struct ceph_mon_client *monc, struct ceph_statfs *buf)
520{
521	struct ceph_mon_generic_request *req;
522	struct ceph_mon_statfs *h;
523	int err;
524
525	req = kzalloc(sizeof(*req), GFP_NOFS);
526	if (!req)
527		return -ENOMEM;
528
529	kref_init(&req->kref);
530	req->buf = buf;
531	req->buf_len = sizeof(*buf);
532	init_completion(&req->completion);
533
534	err = -ENOMEM;
535	req->request = ceph_msg_new(CEPH_MSG_STATFS, sizeof(*h), GFP_NOFS,
536				    true);
537	if (!req->request)
538		goto out;
539	req->reply = ceph_msg_new(CEPH_MSG_STATFS_REPLY, 1024, GFP_NOFS,
540				  true);
541	if (!req->reply)
542		goto out;
543
544	/* fill out request */
545	h = req->request->front.iov_base;
546	h->monhdr.have_version = 0;
547	h->monhdr.session_mon = cpu_to_le16(-1);
548	h->monhdr.session_mon_tid = 0;
549	h->fsid = monc->monmap->fsid;
550
551	err = do_generic_request(monc, req);
552
553out:
554	kref_put(&req->kref, release_generic_request);
555	return err;
556}
557EXPORT_SYMBOL(ceph_monc_do_statfs);
558
559/*
560 * pool ops
561 */
562static int get_poolop_reply_buf(const char *src, size_t src_len,
563				char *dst, size_t dst_len)
564{
565	u32 buf_len;
566
567	if (src_len != sizeof(u32) + dst_len)
568		return -EINVAL;
569
570	buf_len = le32_to_cpu(*(u32 *)src);
571	if (buf_len != dst_len)
572		return -EINVAL;
573
574	memcpy(dst, src + sizeof(u32), dst_len);
575	return 0;
576}
577
578static void handle_poolop_reply(struct ceph_mon_client *monc,
579				struct ceph_msg *msg)
580{
581	struct ceph_mon_generic_request *req;
582	struct ceph_mon_poolop_reply *reply = msg->front.iov_base;
583	u64 tid = le64_to_cpu(msg->hdr.tid);
584
585	if (msg->front.iov_len < sizeof(*reply))
586		goto bad;
587	dout("handle_poolop_reply %p tid %llu\n", msg, tid);
588
589	mutex_lock(&monc->mutex);
590	req = __lookup_generic_req(monc, tid);
591	if (req) {
592		if (req->buf_len &&
593		    get_poolop_reply_buf(msg->front.iov_base + sizeof(*reply),
594				     msg->front.iov_len - sizeof(*reply),
595				     req->buf, req->buf_len) < 0) {
596			mutex_unlock(&monc->mutex);
597			goto bad;
598		}
599		req->result = le32_to_cpu(reply->reply_code);
600		get_generic_request(req);
601	}
602	mutex_unlock(&monc->mutex);
603	if (req) {
604		complete(&req->completion);
605		put_generic_request(req);
606	}
607	return;
608
609bad:
610	pr_err("corrupt generic reply, tid %llu\n", tid);
611	ceph_msg_dump(msg);
612}
613
614/*
615 * Do a synchronous pool op.
616 */
617int ceph_monc_do_poolop(struct ceph_mon_client *monc, u32 op,
618			u32 pool, u64 snapid,
619			char *buf, int len)
620{
621	struct ceph_mon_generic_request *req;
622	struct ceph_mon_poolop *h;
623	int err;
624
625	req = kzalloc(sizeof(*req), GFP_NOFS);
626	if (!req)
627		return -ENOMEM;
628
629	kref_init(&req->kref);
630	req->buf = buf;
631	req->buf_len = len;
632	init_completion(&req->completion);
633
634	err = -ENOMEM;
635	req->request = ceph_msg_new(CEPH_MSG_POOLOP, sizeof(*h), GFP_NOFS,
636				    true);
637	if (!req->request)
638		goto out;
639	req->reply = ceph_msg_new(CEPH_MSG_POOLOP_REPLY, 1024, GFP_NOFS,
640				  true);
641	if (!req->reply)
642		goto out;
643
644	/* fill out request */
645	req->request->hdr.version = cpu_to_le16(2);
646	h = req->request->front.iov_base;
647	h->monhdr.have_version = 0;
648	h->monhdr.session_mon = cpu_to_le16(-1);
649	h->monhdr.session_mon_tid = 0;
650	h->fsid = monc->monmap->fsid;
651	h->pool = cpu_to_le32(pool);
652	h->op = cpu_to_le32(op);
653	h->auid = 0;
654	h->snapid = cpu_to_le64(snapid);
655	h->name_len = 0;
656
657	err = do_generic_request(monc, req);
658
659out:
660	kref_put(&req->kref, release_generic_request);
661	return err;
662}
663
664int ceph_monc_create_snapid(struct ceph_mon_client *monc,
665			    u32 pool, u64 *snapid)
666{
667	return ceph_monc_do_poolop(monc,  POOL_OP_CREATE_UNMANAGED_SNAP,
668				   pool, 0, (char *)snapid, sizeof(*snapid));
669
670}
671EXPORT_SYMBOL(ceph_monc_create_snapid);
672
673int ceph_monc_delete_snapid(struct ceph_mon_client *monc,
674			    u32 pool, u64 snapid)
675{
676	return ceph_monc_do_poolop(monc,  POOL_OP_CREATE_UNMANAGED_SNAP,
677				   pool, snapid, 0, 0);
678
679}
680
681/*
682 * Resend pending generic requests.
683 */
684static void __resend_generic_request(struct ceph_mon_client *monc)
685{
686	struct ceph_mon_generic_request *req;
687	struct rb_node *p;
688
689	for (p = rb_first(&monc->generic_request_tree); p; p = rb_next(p)) {
690		req = rb_entry(p, struct ceph_mon_generic_request, node);
691		ceph_msg_revoke(req->request);
692		ceph_con_send(&monc->con, ceph_msg_get(req->request));
693	}
694}
695
696/*
697 * Delayed work.  If we haven't mounted yet, retry.  Otherwise,
698 * renew/retry subscription as needed (in case it is timing out, or we
699 * got an ENOMEM).  And keep the monitor connection alive.
700 */
701static void delayed_work(struct work_struct *work)
702{
703	struct ceph_mon_client *monc =
704		container_of(work, struct ceph_mon_client, delayed_work.work);
705
706	dout("monc delayed_work\n");
707	mutex_lock(&monc->mutex);
708	if (monc->hunting) {
709		__close_session(monc);
710		__open_session(monc);  /* continue hunting */
711	} else {
712		ceph_con_keepalive(&monc->con);
713
714		__validate_auth(monc);
715
716		if (monc->auth->ops->is_authenticated(monc->auth))
717			__send_subscribe(monc);
718	}
719	__schedule_delayed(monc);
720	mutex_unlock(&monc->mutex);
721}
722
723/*
724 * On startup, we build a temporary monmap populated with the IPs
725 * provided by mount(2).
726 */
727static int build_initial_monmap(struct ceph_mon_client *monc)
728{
729	struct ceph_options *opt = monc->client->options;
730	struct ceph_entity_addr *mon_addr = opt->mon_addr;
731	int num_mon = opt->num_mon;
732	int i;
733
734	/* build initial monmap */
735	monc->monmap = kzalloc(sizeof(*monc->monmap) +
736			       num_mon*sizeof(monc->monmap->mon_inst[0]),
737			       GFP_KERNEL);
738	if (!monc->monmap)
739		return -ENOMEM;
740	for (i = 0; i < num_mon; i++) {
741		monc->monmap->mon_inst[i].addr = mon_addr[i];
742		monc->monmap->mon_inst[i].addr.nonce = 0;
743		monc->monmap->mon_inst[i].name.type =
744			CEPH_ENTITY_TYPE_MON;
745		monc->monmap->mon_inst[i].name.num = cpu_to_le64(i);
746	}
747	monc->monmap->num_mon = num_mon;
748	monc->have_fsid = false;
749	return 0;
750}
751
752int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
753{
754	int err = 0;
755
756	dout("init\n");
757	memset(monc, 0, sizeof(*monc));
758	monc->client = cl;
759	monc->monmap = NULL;
760	mutex_init(&monc->mutex);
761
762	err = build_initial_monmap(monc);
763	if (err)
764		goto out;
765
766	/* connection */
767	/* authentication */
768	monc->auth = ceph_auth_init(cl->options->name,
769				    cl->options->key);
770	if (IS_ERR(monc->auth)) {
771		err = PTR_ERR(monc->auth);
772		goto out_monmap;
773	}
774	monc->auth->want_keys =
775		CEPH_ENTITY_TYPE_AUTH | CEPH_ENTITY_TYPE_MON |
776		CEPH_ENTITY_TYPE_OSD | CEPH_ENTITY_TYPE_MDS;
777
778	/* msgs */
779	err = -ENOMEM;
780	monc->m_subscribe_ack = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE_ACK,
781				     sizeof(struct ceph_mon_subscribe_ack),
782				     GFP_NOFS, true);
783	if (!monc->m_subscribe_ack)
784		goto out_auth;
785
786	monc->m_subscribe = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 96, GFP_NOFS,
787					 true);
788	if (!monc->m_subscribe)
789		goto out_subscribe_ack;
790
791	monc->m_auth_reply = ceph_msg_new(CEPH_MSG_AUTH_REPLY, 4096, GFP_NOFS,
792					  true);
793	if (!monc->m_auth_reply)
794		goto out_subscribe;
795
796	monc->m_auth = ceph_msg_new(CEPH_MSG_AUTH, 4096, GFP_NOFS, true);
797	monc->pending_auth = 0;
798	if (!monc->m_auth)
799		goto out_auth_reply;
800
801	monc->cur_mon = -1;
802	monc->hunting = true;
803	monc->sub_renew_after = jiffies;
804	monc->sub_sent = 0;
805
806	INIT_DELAYED_WORK(&monc->delayed_work, delayed_work);
807	monc->generic_request_tree = RB_ROOT;
808	monc->num_generic_requests = 0;
809	monc->last_tid = 0;
810
811	monc->have_mdsmap = 0;
812	monc->have_osdmap = 0;
813	monc->want_next_osdmap = 1;
814	return 0;
815
816out_auth_reply:
817	ceph_msg_put(monc->m_auth_reply);
818out_subscribe:
819	ceph_msg_put(monc->m_subscribe);
820out_subscribe_ack:
821	ceph_msg_put(monc->m_subscribe_ack);
822out_auth:
823	ceph_auth_destroy(monc->auth);
824out_monmap:
825	kfree(monc->monmap);
826out:
827	return err;
828}
829EXPORT_SYMBOL(ceph_monc_init);
830
831void ceph_monc_stop(struct ceph_mon_client *monc)
832{
833	dout("stop\n");
834	cancel_delayed_work_sync(&monc->delayed_work);
835
836	mutex_lock(&monc->mutex);
837	__close_session(monc);
838
839	mutex_unlock(&monc->mutex);
840
841	ceph_auth_destroy(monc->auth);
842
843	ceph_msg_put(monc->m_auth);
844	ceph_msg_put(monc->m_auth_reply);
845	ceph_msg_put(monc->m_subscribe);
846	ceph_msg_put(monc->m_subscribe_ack);
847
848	kfree(monc->monmap);
849}
850EXPORT_SYMBOL(ceph_monc_stop);
851
852static void handle_auth_reply(struct ceph_mon_client *monc,
853			      struct ceph_msg *msg)
854{
855	int ret;
856	int was_auth = 0;
857
858	mutex_lock(&monc->mutex);
859	if (monc->auth->ops)
860		was_auth = monc->auth->ops->is_authenticated(monc->auth);
861	monc->pending_auth = 0;
862	ret = ceph_handle_auth_reply(monc->auth, msg->front.iov_base,
863				     msg->front.iov_len,
864				     monc->m_auth->front.iov_base,
865				     monc->m_auth->front_max);
866	if (ret < 0) {
867		monc->client->auth_err = ret;
868		wake_up_all(&monc->client->auth_wq);
869	} else if (ret > 0) {
870		__send_prepared_auth_request(monc, ret);
871	} else if (!was_auth && monc->auth->ops->is_authenticated(monc->auth)) {
872		dout("authenticated, starting session\n");
873
874		monc->client->msgr.inst.name.type = CEPH_ENTITY_TYPE_CLIENT;
875		monc->client->msgr.inst.name.num =
876					cpu_to_le64(monc->auth->global_id);
877
878		__send_subscribe(monc);
879		__resend_generic_request(monc);
880	}
881	mutex_unlock(&monc->mutex);
882}
883
884static int __validate_auth(struct ceph_mon_client *monc)
885{
886	int ret;
887
888	if (monc->pending_auth)
889		return 0;
890
891	ret = ceph_build_auth(monc->auth, monc->m_auth->front.iov_base,
892			      monc->m_auth->front_max);
893	if (ret <= 0)
894		return ret; /* either an error, or no need to authenticate */
895	__send_prepared_auth_request(monc, ret);
896	return 0;
897}
898
899int ceph_monc_validate_auth(struct ceph_mon_client *monc)
900{
901	int ret;
902
903	mutex_lock(&monc->mutex);
904	ret = __validate_auth(monc);
905	mutex_unlock(&monc->mutex);
906	return ret;
907}
908EXPORT_SYMBOL(ceph_monc_validate_auth);
909
910/*
911 * handle incoming message
912 */
913static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
914{
915	struct ceph_mon_client *monc = con->private;
916	int type = le16_to_cpu(msg->hdr.type);
917
918	if (!monc)
919		return;
920
921	switch (type) {
922	case CEPH_MSG_AUTH_REPLY:
923		handle_auth_reply(monc, msg);
924		break;
925
926	case CEPH_MSG_MON_SUBSCRIBE_ACK:
927		handle_subscribe_ack(monc, msg);
928		break;
929
930	case CEPH_MSG_STATFS_REPLY:
931		handle_statfs_reply(monc, msg);
932		break;
933
934	case CEPH_MSG_POOLOP_REPLY:
935		handle_poolop_reply(monc, msg);
936		break;
937
938	case CEPH_MSG_MON_MAP:
939		ceph_monc_handle_map(monc, msg);
940		break;
941
942	case CEPH_MSG_OSD_MAP:
943		ceph_osdc_handle_map(&monc->client->osdc, msg);
944		break;
945
946	default:
947		/* can the chained handler handle it? */
948		if (monc->client->extra_mon_dispatch &&
949		    monc->client->extra_mon_dispatch(monc->client, msg) == 0)
950			break;
951
952		pr_err("received unknown message type %d %s\n", type,
953		       ceph_msg_type_name(type));
954	}
955	ceph_msg_put(msg);
956}
957
958/*
959 * Allocate memory for incoming message
960 */
961static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
962				      struct ceph_msg_header *hdr,
963				      int *skip)
964{
965	struct ceph_mon_client *monc = con->private;
966	int type = le16_to_cpu(hdr->type);
967	int front_len = le32_to_cpu(hdr->front_len);
968	struct ceph_msg *m = NULL;
969
970	*skip = 0;
971
972	switch (type) {
973	case CEPH_MSG_MON_SUBSCRIBE_ACK:
974		m = ceph_msg_get(monc->m_subscribe_ack);
975		break;
976	case CEPH_MSG_POOLOP_REPLY:
977	case CEPH_MSG_STATFS_REPLY:
978		return get_generic_reply(con, hdr, skip);
979	case CEPH_MSG_AUTH_REPLY:
980		m = ceph_msg_get(monc->m_auth_reply);
981		break;
982	case CEPH_MSG_MON_MAP:
983	case CEPH_MSG_MDS_MAP:
984	case CEPH_MSG_OSD_MAP:
985		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
986		if (!m)
987			return NULL;	/* ENOMEM--return skip == 0 */
988		break;
989	}
990
991	if (!m) {
992		pr_info("alloc_msg unknown type %d\n", type);
993		*skip = 1;
994	}
995	return m;
996}
997
998/*
999 * If the monitor connection resets, pick a new monitor and resubmit
1000 * any pending requests.
1001 */
1002static void mon_fault(struct ceph_connection *con)
1003{
1004	struct ceph_mon_client *monc = con->private;
1005
1006	if (!monc)
1007		return;
1008
1009	dout("mon_fault\n");
1010	mutex_lock(&monc->mutex);
1011	if (!con->private)
1012		goto out;
1013
1014	if (!monc->hunting)
1015		pr_info("mon%d %s session lost, "
1016			"hunting for new mon\n", monc->cur_mon,
1017			ceph_pr_addr(&monc->con.peer_addr.in_addr));
1018
1019	__close_session(monc);
1020	if (!monc->hunting) {
1021		/* start hunting */
1022		monc->hunting = true;
1023		__open_session(monc);
1024	} else {
1025		/* already hunting, let's wait a bit */
1026		__schedule_delayed(monc);
1027	}
1028out:
1029	mutex_unlock(&monc->mutex);
1030}
1031
1032/*
1033 * We can ignore refcounting on the connection struct, as all references
1034 * will come from the messenger workqueue, which is drained prior to
1035 * mon_client destruction.
1036 */
1037static struct ceph_connection *con_get(struct ceph_connection *con)
1038{
1039	return con;
1040}
1041
1042static void con_put(struct ceph_connection *con)
1043{
1044}
1045
1046static const struct ceph_connection_operations mon_con_ops = {
1047	.get = con_get,
1048	.put = con_put,
1049	.dispatch = dispatch,
1050	.fault = mon_fault,
1051	.alloc_msg = mon_alloc_msg,
1052};
1053