xref: /openbmc/linux/net/ceph/messenger.c (revision 97da55fc)
1 #include <linux/ceph/ceph_debug.h>
2 
3 #include <linux/crc32c.h>
4 #include <linux/ctype.h>
5 #include <linux/highmem.h>
6 #include <linux/inet.h>
7 #include <linux/kthread.h>
8 #include <linux/net.h>
9 #include <linux/slab.h>
10 #include <linux/socket.h>
11 #include <linux/string.h>
12 #ifdef	CONFIG_BLOCK
13 #include <linux/bio.h>
14 #endif	/* CONFIG_BLOCK */
15 #include <linux/dns_resolver.h>
16 #include <net/tcp.h>
17 
18 #include <linux/ceph/libceph.h>
19 #include <linux/ceph/messenger.h>
20 #include <linux/ceph/decode.h>
21 #include <linux/ceph/pagelist.h>
22 #include <linux/export.h>
23 
24 /*
25  * Ceph uses the messenger to exchange ceph_msg messages with other
26  * hosts in the system.  The messenger provides ordered and reliable
27  * delivery.  We tolerate TCP disconnects by reconnecting (with
28  * exponential backoff) in the case of a fault (disconnection, bad
29  * crc, protocol error).  Acks allow sent messages to be discarded by
30  * the sender.
31  */
32 
33 /*
34  * We track the state of the socket on a given connection using
35  * values defined below.  The transition to a new socket state is
36  * handled by a function which verifies we aren't coming from an
37  * unexpected state.
38  *
39  *      --------
40  *      | NEW* |  transient initial state
41  *      --------
42  *          | con_sock_state_init()
43  *          v
44  *      ----------
45  *      | CLOSED |  initialized, but no socket (and no
46  *      ----------  TCP connection)
47  *       ^      \
48  *       |       \ con_sock_state_connecting()
49  *       |        ----------------------
50  *       |                              \
51  *       + con_sock_state_closed()       \
52  *       |+---------------------------    \
53  *       | \                          \    \
54  *       |  -----------                \    \
55  *       |  | CLOSING |  socket event;  \    \
56  *       |  -----------  await close     \    \
57  *       |       ^                        \   |
58  *       |       |                         \  |
59  *       |       + con_sock_state_closing() \ |
60  *       |      / \                         | |
61  *       |     /   ---------------          | |
62  *       |    /                   \         v v
63  *       |   /                    --------------
64  *       |  /    -----------------| CONNECTING |  socket created, TCP
65  *       |  |   /                 --------------  connect initiated
66  *       |  |   | con_sock_state_connected()
67  *       |  |   v
68  *      -------------
69  *      | CONNECTED |  TCP connection established
70  *      -------------
71  *
72  * State values for ceph_connection->sock_state; NEW is assumed to be 0.
73  */
74 
75 #define CON_SOCK_STATE_NEW		0	/* -> CLOSED */
76 #define CON_SOCK_STATE_CLOSED		1	/* -> CONNECTING */
77 #define CON_SOCK_STATE_CONNECTING	2	/* -> CONNECTED or -> CLOSING */
78 #define CON_SOCK_STATE_CONNECTED	3	/* -> CLOSING or -> CLOSED */
79 #define CON_SOCK_STATE_CLOSING		4	/* -> CLOSED */
80 
81 /*
82  * connection states
83  */
84 #define CON_STATE_CLOSED        1  /* -> PREOPEN */
85 #define CON_STATE_PREOPEN       2  /* -> CONNECTING, CLOSED */
86 #define CON_STATE_CONNECTING    3  /* -> NEGOTIATING, CLOSED */
87 #define CON_STATE_NEGOTIATING   4  /* -> OPEN, CLOSED */
88 #define CON_STATE_OPEN          5  /* -> STANDBY, CLOSED */
89 #define CON_STATE_STANDBY       6  /* -> PREOPEN, CLOSED */
90 
91 /*
92  * ceph_connection flag bits
93  */
94 #define CON_FLAG_LOSSYTX           0  /* we can close channel or drop
95 				       * messages on errors */
96 #define CON_FLAG_KEEPALIVE_PENDING 1  /* we need to send a keepalive */
97 #define CON_FLAG_WRITE_PENDING	   2  /* we have data ready to send */
98 #define CON_FLAG_SOCK_CLOSED	   3  /* socket state changed to closed */
99 #define CON_FLAG_BACKOFF           4  /* need to retry queuing delayed work */
100 
101 static bool con_flag_valid(unsigned long con_flag)
102 {
103 	switch (con_flag) {
104 	case CON_FLAG_LOSSYTX:
105 	case CON_FLAG_KEEPALIVE_PENDING:
106 	case CON_FLAG_WRITE_PENDING:
107 	case CON_FLAG_SOCK_CLOSED:
108 	case CON_FLAG_BACKOFF:
109 		return true;
110 	default:
111 		return false;
112 	}
113 }
114 
115 static void con_flag_clear(struct ceph_connection *con, unsigned long con_flag)
116 {
117 	BUG_ON(!con_flag_valid(con_flag));
118 
119 	clear_bit(con_flag, &con->flags);
120 }
121 
122 static void con_flag_set(struct ceph_connection *con, unsigned long con_flag)
123 {
124 	BUG_ON(!con_flag_valid(con_flag));
125 
126 	set_bit(con_flag, &con->flags);
127 }
128 
129 static bool con_flag_test(struct ceph_connection *con, unsigned long con_flag)
130 {
131 	BUG_ON(!con_flag_valid(con_flag));
132 
133 	return test_bit(con_flag, &con->flags);
134 }
135 
136 static bool con_flag_test_and_clear(struct ceph_connection *con,
137 					unsigned long con_flag)
138 {
139 	BUG_ON(!con_flag_valid(con_flag));
140 
141 	return test_and_clear_bit(con_flag, &con->flags);
142 }
143 
144 static bool con_flag_test_and_set(struct ceph_connection *con,
145 					unsigned long con_flag)
146 {
147 	BUG_ON(!con_flag_valid(con_flag));
148 
149 	return test_and_set_bit(con_flag, &con->flags);
150 }
151 
152 /* static tag bytes (protocol control messages) */
153 static char tag_msg = CEPH_MSGR_TAG_MSG;
154 static char tag_ack = CEPH_MSGR_TAG_ACK;
155 static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
156 
157 #ifdef CONFIG_LOCKDEP
158 static struct lock_class_key socket_class;
159 #endif
160 
161 /*
162  * When skipping (ignoring) a block of input we read it into a "skip
163  * buffer," which is this many bytes in size.
164  */
165 #define SKIP_BUF_SIZE	1024
166 
167 static void queue_con(struct ceph_connection *con);
168 static void con_work(struct work_struct *);
169 static void con_fault(struct ceph_connection *con);
170 
171 /*
172  * Nicely render a sockaddr as a string.  An array of formatted
173  * strings is used, to approximate reentrancy.
174  */
175 #define ADDR_STR_COUNT_LOG	5	/* log2(# address strings in array) */
176 #define ADDR_STR_COUNT		(1 << ADDR_STR_COUNT_LOG)
177 #define ADDR_STR_COUNT_MASK	(ADDR_STR_COUNT - 1)
178 #define MAX_ADDR_STR_LEN	64	/* 54 is enough */
179 
180 static char addr_str[ADDR_STR_COUNT][MAX_ADDR_STR_LEN];
181 static atomic_t addr_str_seq = ATOMIC_INIT(0);
182 
183 static struct page *zero_page;		/* used in certain error cases */
184 
185 const char *ceph_pr_addr(const struct sockaddr_storage *ss)
186 {
187 	int i;
188 	char *s;
189 	struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
190 	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
191 
192 	i = atomic_inc_return(&addr_str_seq) & ADDR_STR_COUNT_MASK;
193 	s = addr_str[i];
194 
195 	switch (ss->ss_family) {
196 	case AF_INET:
197 		snprintf(s, MAX_ADDR_STR_LEN, "%pI4:%hu", &in4->sin_addr,
198 			 ntohs(in4->sin_port));
199 		break;
200 
201 	case AF_INET6:
202 		snprintf(s, MAX_ADDR_STR_LEN, "[%pI6c]:%hu", &in6->sin6_addr,
203 			 ntohs(in6->sin6_port));
204 		break;
205 
206 	default:
207 		snprintf(s, MAX_ADDR_STR_LEN, "(unknown sockaddr family %hu)",
208 			 ss->ss_family);
209 	}
210 
211 	return s;
212 }
213 EXPORT_SYMBOL(ceph_pr_addr);
214 
215 static void encode_my_addr(struct ceph_messenger *msgr)
216 {
217 	memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
218 	ceph_encode_addr(&msgr->my_enc_addr);
219 }
220 
221 /*
222  * work queue for all reading and writing to/from the socket.
223  */
224 static struct workqueue_struct *ceph_msgr_wq;
225 
226 static void _ceph_msgr_exit(void)
227 {
228 	if (ceph_msgr_wq) {
229 		destroy_workqueue(ceph_msgr_wq);
230 		ceph_msgr_wq = NULL;
231 	}
232 
233 	BUG_ON(zero_page == NULL);
234 	kunmap(zero_page);
235 	page_cache_release(zero_page);
236 	zero_page = NULL;
237 }
238 
239 int ceph_msgr_init(void)
240 {
241 	BUG_ON(zero_page != NULL);
242 	zero_page = ZERO_PAGE(0);
243 	page_cache_get(zero_page);
244 
245 	ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_NON_REENTRANT, 0);
246 	if (ceph_msgr_wq)
247 		return 0;
248 
249 	pr_err("msgr_init failed to create workqueue\n");
250 	_ceph_msgr_exit();
251 
252 	return -ENOMEM;
253 }
254 EXPORT_SYMBOL(ceph_msgr_init);
255 
256 void ceph_msgr_exit(void)
257 {
258 	BUG_ON(ceph_msgr_wq == NULL);
259 
260 	_ceph_msgr_exit();
261 }
262 EXPORT_SYMBOL(ceph_msgr_exit);
263 
264 void ceph_msgr_flush(void)
265 {
266 	flush_workqueue(ceph_msgr_wq);
267 }
268 EXPORT_SYMBOL(ceph_msgr_flush);
269 
270 /* Connection socket state transition functions */
271 
272 static void con_sock_state_init(struct ceph_connection *con)
273 {
274 	int old_state;
275 
276 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
277 	if (WARN_ON(old_state != CON_SOCK_STATE_NEW))
278 		printk("%s: unexpected old state %d\n", __func__, old_state);
279 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
280 	     CON_SOCK_STATE_CLOSED);
281 }
282 
283 static void con_sock_state_connecting(struct ceph_connection *con)
284 {
285 	int old_state;
286 
287 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTING);
288 	if (WARN_ON(old_state != CON_SOCK_STATE_CLOSED))
289 		printk("%s: unexpected old state %d\n", __func__, old_state);
290 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
291 	     CON_SOCK_STATE_CONNECTING);
292 }
293 
294 static void con_sock_state_connected(struct ceph_connection *con)
295 {
296 	int old_state;
297 
298 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTED);
299 	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING))
300 		printk("%s: unexpected old state %d\n", __func__, old_state);
301 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
302 	     CON_SOCK_STATE_CONNECTED);
303 }
304 
305 static void con_sock_state_closing(struct ceph_connection *con)
306 {
307 	int old_state;
308 
309 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSING);
310 	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING &&
311 			old_state != CON_SOCK_STATE_CONNECTED &&
312 			old_state != CON_SOCK_STATE_CLOSING))
313 		printk("%s: unexpected old state %d\n", __func__, old_state);
314 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
315 	     CON_SOCK_STATE_CLOSING);
316 }
317 
318 static void con_sock_state_closed(struct ceph_connection *con)
319 {
320 	int old_state;
321 
322 	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
323 	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTED &&
324 		    old_state != CON_SOCK_STATE_CLOSING &&
325 		    old_state != CON_SOCK_STATE_CONNECTING &&
326 		    old_state != CON_SOCK_STATE_CLOSED))
327 		printk("%s: unexpected old state %d\n", __func__, old_state);
328 	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
329 	     CON_SOCK_STATE_CLOSED);
330 }
331 
332 /*
333  * socket callback functions
334  */
335 
336 /* data available on socket, or listen socket received a connect */
337 static void ceph_sock_data_ready(struct sock *sk, int count_unused)
338 {
339 	struct ceph_connection *con = sk->sk_user_data;
340 	if (atomic_read(&con->msgr->stopping)) {
341 		return;
342 	}
343 
344 	if (sk->sk_state != TCP_CLOSE_WAIT) {
345 		dout("%s on %p state = %lu, queueing work\n", __func__,
346 		     con, con->state);
347 		queue_con(con);
348 	}
349 }
350 
351 /* socket has buffer space for writing */
352 static void ceph_sock_write_space(struct sock *sk)
353 {
354 	struct ceph_connection *con = sk->sk_user_data;
355 
356 	/* only queue to workqueue if there is data we want to write,
357 	 * and there is sufficient space in the socket buffer to accept
358 	 * more data.  clear SOCK_NOSPACE so that ceph_sock_write_space()
359 	 * doesn't get called again until try_write() fills the socket
360 	 * buffer. See net/ipv4/tcp_input.c:tcp_check_space()
361 	 * and net/core/stream.c:sk_stream_write_space().
362 	 */
363 	if (con_flag_test(con, CON_FLAG_WRITE_PENDING)) {
364 		if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
365 			dout("%s %p queueing write work\n", __func__, con);
366 			clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
367 			queue_con(con);
368 		}
369 	} else {
370 		dout("%s %p nothing to write\n", __func__, con);
371 	}
372 }
373 
374 /* socket's state has changed */
375 static void ceph_sock_state_change(struct sock *sk)
376 {
377 	struct ceph_connection *con = sk->sk_user_data;
378 
379 	dout("%s %p state = %lu sk_state = %u\n", __func__,
380 	     con, con->state, sk->sk_state);
381 
382 	switch (sk->sk_state) {
383 	case TCP_CLOSE:
384 		dout("%s TCP_CLOSE\n", __func__);
385 	case TCP_CLOSE_WAIT:
386 		dout("%s TCP_CLOSE_WAIT\n", __func__);
387 		con_sock_state_closing(con);
388 		con_flag_set(con, CON_FLAG_SOCK_CLOSED);
389 		queue_con(con);
390 		break;
391 	case TCP_ESTABLISHED:
392 		dout("%s TCP_ESTABLISHED\n", __func__);
393 		con_sock_state_connected(con);
394 		queue_con(con);
395 		break;
396 	default:	/* Everything else is uninteresting */
397 		break;
398 	}
399 }
400 
401 /*
402  * set up socket callbacks
403  */
404 static void set_sock_callbacks(struct socket *sock,
405 			       struct ceph_connection *con)
406 {
407 	struct sock *sk = sock->sk;
408 	sk->sk_user_data = con;
409 	sk->sk_data_ready = ceph_sock_data_ready;
410 	sk->sk_write_space = ceph_sock_write_space;
411 	sk->sk_state_change = ceph_sock_state_change;
412 }
413 
414 
415 /*
416  * socket helpers
417  */
418 
419 /*
420  * initiate connection to a remote socket.
421  */
422 static int ceph_tcp_connect(struct ceph_connection *con)
423 {
424 	struct sockaddr_storage *paddr = &con->peer_addr.in_addr;
425 	struct socket *sock;
426 	int ret;
427 
428 	BUG_ON(con->sock);
429 	ret = sock_create_kern(con->peer_addr.in_addr.ss_family, SOCK_STREAM,
430 			       IPPROTO_TCP, &sock);
431 	if (ret)
432 		return ret;
433 	sock->sk->sk_allocation = GFP_NOFS;
434 
435 #ifdef CONFIG_LOCKDEP
436 	lockdep_set_class(&sock->sk->sk_lock, &socket_class);
437 #endif
438 
439 	set_sock_callbacks(sock, con);
440 
441 	dout("connect %s\n", ceph_pr_addr(&con->peer_addr.in_addr));
442 
443 	con_sock_state_connecting(con);
444 	ret = sock->ops->connect(sock, (struct sockaddr *)paddr, sizeof(*paddr),
445 				 O_NONBLOCK);
446 	if (ret == -EINPROGRESS) {
447 		dout("connect %s EINPROGRESS sk_state = %u\n",
448 		     ceph_pr_addr(&con->peer_addr.in_addr),
449 		     sock->sk->sk_state);
450 	} else if (ret < 0) {
451 		pr_err("connect %s error %d\n",
452 		       ceph_pr_addr(&con->peer_addr.in_addr), ret);
453 		sock_release(sock);
454 		con->error_msg = "connect error";
455 
456 		return ret;
457 	}
458 	con->sock = sock;
459 	return 0;
460 }
461 
462 static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
463 {
464 	struct kvec iov = {buf, len};
465 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
466 	int r;
467 
468 	r = kernel_recvmsg(sock, &msg, &iov, 1, len, msg.msg_flags);
469 	if (r == -EAGAIN)
470 		r = 0;
471 	return r;
472 }
473 
474 /*
475  * write something.  @more is true if caller will be sending more data
476  * shortly.
477  */
478 static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
479 		     size_t kvlen, size_t len, int more)
480 {
481 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
482 	int r;
483 
484 	if (more)
485 		msg.msg_flags |= MSG_MORE;
486 	else
487 		msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
488 
489 	r = kernel_sendmsg(sock, &msg, iov, kvlen, len);
490 	if (r == -EAGAIN)
491 		r = 0;
492 	return r;
493 }
494 
495 static int ceph_tcp_sendpage(struct socket *sock, struct page *page,
496 		     int offset, size_t size, int more)
497 {
498 	int flags = MSG_DONTWAIT | MSG_NOSIGNAL | (more ? MSG_MORE : MSG_EOR);
499 	int ret;
500 
501 	ret = kernel_sendpage(sock, page, offset, size, flags);
502 	if (ret == -EAGAIN)
503 		ret = 0;
504 
505 	return ret;
506 }
507 
508 
509 /*
510  * Shutdown/close the socket for the given connection.
511  */
512 static int con_close_socket(struct ceph_connection *con)
513 {
514 	int rc = 0;
515 
516 	dout("con_close_socket on %p sock %p\n", con, con->sock);
517 	if (con->sock) {
518 		rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
519 		sock_release(con->sock);
520 		con->sock = NULL;
521 	}
522 
523 	/*
524 	 * Forcibly clear the SOCK_CLOSED flag.  It gets set
525 	 * independent of the connection mutex, and we could have
526 	 * received a socket close event before we had the chance to
527 	 * shut the socket down.
528 	 */
529 	con_flag_clear(con, CON_FLAG_SOCK_CLOSED);
530 
531 	con_sock_state_closed(con);
532 	return rc;
533 }
534 
535 /*
536  * Reset a connection.  Discard all incoming and outgoing messages
537  * and clear *_seq state.
538  */
539 static void ceph_msg_remove(struct ceph_msg *msg)
540 {
541 	list_del_init(&msg->list_head);
542 	BUG_ON(msg->con == NULL);
543 	msg->con->ops->put(msg->con);
544 	msg->con = NULL;
545 
546 	ceph_msg_put(msg);
547 }
548 static void ceph_msg_remove_list(struct list_head *head)
549 {
550 	while (!list_empty(head)) {
551 		struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
552 							list_head);
553 		ceph_msg_remove(msg);
554 	}
555 }
556 
557 static void reset_connection(struct ceph_connection *con)
558 {
559 	/* reset connection, out_queue, msg_ and connect_seq */
560 	/* discard existing out_queue and msg_seq */
561 	dout("reset_connection %p\n", con);
562 	ceph_msg_remove_list(&con->out_queue);
563 	ceph_msg_remove_list(&con->out_sent);
564 
565 	if (con->in_msg) {
566 		BUG_ON(con->in_msg->con != con);
567 		con->in_msg->con = NULL;
568 		ceph_msg_put(con->in_msg);
569 		con->in_msg = NULL;
570 		con->ops->put(con);
571 	}
572 
573 	con->connect_seq = 0;
574 	con->out_seq = 0;
575 	if (con->out_msg) {
576 		ceph_msg_put(con->out_msg);
577 		con->out_msg = NULL;
578 	}
579 	con->in_seq = 0;
580 	con->in_seq_acked = 0;
581 }
582 
583 /*
584  * mark a peer down.  drop any open connections.
585  */
586 void ceph_con_close(struct ceph_connection *con)
587 {
588 	mutex_lock(&con->mutex);
589 	dout("con_close %p peer %s\n", con,
590 	     ceph_pr_addr(&con->peer_addr.in_addr));
591 	con->state = CON_STATE_CLOSED;
592 
593 	con_flag_clear(con, CON_FLAG_LOSSYTX);	/* so we retry next connect */
594 	con_flag_clear(con, CON_FLAG_KEEPALIVE_PENDING);
595 	con_flag_clear(con, CON_FLAG_WRITE_PENDING);
596 	con_flag_clear(con, CON_FLAG_BACKOFF);
597 
598 	reset_connection(con);
599 	con->peer_global_seq = 0;
600 	cancel_delayed_work(&con->work);
601 	con_close_socket(con);
602 	mutex_unlock(&con->mutex);
603 }
604 EXPORT_SYMBOL(ceph_con_close);
605 
606 /*
607  * Reopen a closed connection, with a new peer address.
608  */
609 void ceph_con_open(struct ceph_connection *con,
610 		   __u8 entity_type, __u64 entity_num,
611 		   struct ceph_entity_addr *addr)
612 {
613 	mutex_lock(&con->mutex);
614 	dout("con_open %p %s\n", con, ceph_pr_addr(&addr->in_addr));
615 
616 	WARN_ON(con->state != CON_STATE_CLOSED);
617 	con->state = CON_STATE_PREOPEN;
618 
619 	con->peer_name.type = (__u8) entity_type;
620 	con->peer_name.num = cpu_to_le64(entity_num);
621 
622 	memcpy(&con->peer_addr, addr, sizeof(*addr));
623 	con->delay = 0;      /* reset backoff memory */
624 	mutex_unlock(&con->mutex);
625 	queue_con(con);
626 }
627 EXPORT_SYMBOL(ceph_con_open);
628 
629 /*
630  * return true if this connection ever successfully opened
631  */
632 bool ceph_con_opened(struct ceph_connection *con)
633 {
634 	return con->connect_seq > 0;
635 }
636 
637 /*
638  * initialize a new connection.
639  */
640 void ceph_con_init(struct ceph_connection *con, void *private,
641 	const struct ceph_connection_operations *ops,
642 	struct ceph_messenger *msgr)
643 {
644 	dout("con_init %p\n", con);
645 	memset(con, 0, sizeof(*con));
646 	con->private = private;
647 	con->ops = ops;
648 	con->msgr = msgr;
649 
650 	con_sock_state_init(con);
651 
652 	mutex_init(&con->mutex);
653 	INIT_LIST_HEAD(&con->out_queue);
654 	INIT_LIST_HEAD(&con->out_sent);
655 	INIT_DELAYED_WORK(&con->work, con_work);
656 
657 	con->state = CON_STATE_CLOSED;
658 }
659 EXPORT_SYMBOL(ceph_con_init);
660 
661 
662 /*
663  * We maintain a global counter to order connection attempts.  Get
664  * a unique seq greater than @gt.
665  */
666 static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
667 {
668 	u32 ret;
669 
670 	spin_lock(&msgr->global_seq_lock);
671 	if (msgr->global_seq < gt)
672 		msgr->global_seq = gt;
673 	ret = ++msgr->global_seq;
674 	spin_unlock(&msgr->global_seq_lock);
675 	return ret;
676 }
677 
678 static void con_out_kvec_reset(struct ceph_connection *con)
679 {
680 	con->out_kvec_left = 0;
681 	con->out_kvec_bytes = 0;
682 	con->out_kvec_cur = &con->out_kvec[0];
683 }
684 
685 static void con_out_kvec_add(struct ceph_connection *con,
686 				size_t size, void *data)
687 {
688 	int index;
689 
690 	index = con->out_kvec_left;
691 	BUG_ON(index >= ARRAY_SIZE(con->out_kvec));
692 
693 	con->out_kvec[index].iov_len = size;
694 	con->out_kvec[index].iov_base = data;
695 	con->out_kvec_left++;
696 	con->out_kvec_bytes += size;
697 }
698 
699 #ifdef CONFIG_BLOCK
700 static void init_bio_iter(struct bio *bio, struct bio **iter, int *seg)
701 {
702 	if (!bio) {
703 		*iter = NULL;
704 		*seg = 0;
705 		return;
706 	}
707 	*iter = bio;
708 	*seg = bio->bi_idx;
709 }
710 
711 static void iter_bio_next(struct bio **bio_iter, int *seg)
712 {
713 	if (*bio_iter == NULL)
714 		return;
715 
716 	BUG_ON(*seg >= (*bio_iter)->bi_vcnt);
717 
718 	(*seg)++;
719 	if (*seg == (*bio_iter)->bi_vcnt)
720 		init_bio_iter((*bio_iter)->bi_next, bio_iter, seg);
721 }
722 #endif
723 
724 static void prepare_write_message_data(struct ceph_connection *con)
725 {
726 	struct ceph_msg *msg = con->out_msg;
727 
728 	BUG_ON(!msg);
729 	BUG_ON(!msg->hdr.data_len);
730 
731 	/* initialize page iterator */
732 	con->out_msg_pos.page = 0;
733 	if (msg->pages)
734 		con->out_msg_pos.page_pos = msg->page_alignment;
735 	else
736 		con->out_msg_pos.page_pos = 0;
737 #ifdef CONFIG_BLOCK
738 	if (msg->bio)
739 		init_bio_iter(msg->bio, &msg->bio_iter, &msg->bio_seg);
740 #endif
741 	con->out_msg_pos.data_pos = 0;
742 	con->out_msg_pos.did_page_crc = false;
743 	con->out_more = 1;  /* data + footer will follow */
744 }
745 
746 /*
747  * Prepare footer for currently outgoing message, and finish things
748  * off.  Assumes out_kvec* are already valid.. we just add on to the end.
749  */
750 static void prepare_write_message_footer(struct ceph_connection *con)
751 {
752 	struct ceph_msg *m = con->out_msg;
753 	int v = con->out_kvec_left;
754 
755 	m->footer.flags |= CEPH_MSG_FOOTER_COMPLETE;
756 
757 	dout("prepare_write_message_footer %p\n", con);
758 	con->out_kvec_is_msg = true;
759 	con->out_kvec[v].iov_base = &m->footer;
760 	con->out_kvec[v].iov_len = sizeof(m->footer);
761 	con->out_kvec_bytes += sizeof(m->footer);
762 	con->out_kvec_left++;
763 	con->out_more = m->more_to_follow;
764 	con->out_msg_done = true;
765 }
766 
767 /*
768  * Prepare headers for the next outgoing message.
769  */
770 static void prepare_write_message(struct ceph_connection *con)
771 {
772 	struct ceph_msg *m;
773 	u32 crc;
774 
775 	con_out_kvec_reset(con);
776 	con->out_kvec_is_msg = true;
777 	con->out_msg_done = false;
778 
779 	/* Sneak an ack in there first?  If we can get it into the same
780 	 * TCP packet that's a good thing. */
781 	if (con->in_seq > con->in_seq_acked) {
782 		con->in_seq_acked = con->in_seq;
783 		con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
784 		con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
785 		con_out_kvec_add(con, sizeof (con->out_temp_ack),
786 			&con->out_temp_ack);
787 	}
788 
789 	BUG_ON(list_empty(&con->out_queue));
790 	m = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
791 	con->out_msg = m;
792 	BUG_ON(m->con != con);
793 
794 	/* put message on sent list */
795 	ceph_msg_get(m);
796 	list_move_tail(&m->list_head, &con->out_sent);
797 
798 	/*
799 	 * only assign outgoing seq # if we haven't sent this message
800 	 * yet.  if it is requeued, resend with it's original seq.
801 	 */
802 	if (m->needs_out_seq) {
803 		m->hdr.seq = cpu_to_le64(++con->out_seq);
804 		m->needs_out_seq = false;
805 	}
806 #ifdef CONFIG_BLOCK
807 	else
808 		m->bio_iter = NULL;
809 #endif
810 
811 	dout("prepare_write_message %p seq %lld type %d len %d+%d+%d %d pgs\n",
812 	     m, con->out_seq, le16_to_cpu(m->hdr.type),
813 	     le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
814 	     le32_to_cpu(m->hdr.data_len),
815 	     m->nr_pages);
816 	BUG_ON(le32_to_cpu(m->hdr.front_len) != m->front.iov_len);
817 
818 	/* tag + hdr + front + middle */
819 	con_out_kvec_add(con, sizeof (tag_msg), &tag_msg);
820 	con_out_kvec_add(con, sizeof (m->hdr), &m->hdr);
821 	con_out_kvec_add(con, m->front.iov_len, m->front.iov_base);
822 
823 	if (m->middle)
824 		con_out_kvec_add(con, m->middle->vec.iov_len,
825 			m->middle->vec.iov_base);
826 
827 	/* fill in crc (except data pages), footer */
828 	crc = crc32c(0, &m->hdr, offsetof(struct ceph_msg_header, crc));
829 	con->out_msg->hdr.crc = cpu_to_le32(crc);
830 	con->out_msg->footer.flags = 0;
831 
832 	crc = crc32c(0, m->front.iov_base, m->front.iov_len);
833 	con->out_msg->footer.front_crc = cpu_to_le32(crc);
834 	if (m->middle) {
835 		crc = crc32c(0, m->middle->vec.iov_base,
836 				m->middle->vec.iov_len);
837 		con->out_msg->footer.middle_crc = cpu_to_le32(crc);
838 	} else
839 		con->out_msg->footer.middle_crc = 0;
840 	dout("%s front_crc %u middle_crc %u\n", __func__,
841 	     le32_to_cpu(con->out_msg->footer.front_crc),
842 	     le32_to_cpu(con->out_msg->footer.middle_crc));
843 
844 	/* is there a data payload? */
845 	con->out_msg->footer.data_crc = 0;
846 	if (m->hdr.data_len)
847 		prepare_write_message_data(con);
848 	else
849 		/* no, queue up footer too and be done */
850 		prepare_write_message_footer(con);
851 
852 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
853 }
854 
855 /*
856  * Prepare an ack.
857  */
858 static void prepare_write_ack(struct ceph_connection *con)
859 {
860 	dout("prepare_write_ack %p %llu -> %llu\n", con,
861 	     con->in_seq_acked, con->in_seq);
862 	con->in_seq_acked = con->in_seq;
863 
864 	con_out_kvec_reset(con);
865 
866 	con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
867 
868 	con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
869 	con_out_kvec_add(con, sizeof (con->out_temp_ack),
870 				&con->out_temp_ack);
871 
872 	con->out_more = 1;  /* more will follow.. eventually.. */
873 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
874 }
875 
876 /*
877  * Prepare to write keepalive byte.
878  */
879 static void prepare_write_keepalive(struct ceph_connection *con)
880 {
881 	dout("prepare_write_keepalive %p\n", con);
882 	con_out_kvec_reset(con);
883 	con_out_kvec_add(con, sizeof (tag_keepalive), &tag_keepalive);
884 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
885 }
886 
887 /*
888  * Connection negotiation.
889  */
890 
891 static struct ceph_auth_handshake *get_connect_authorizer(struct ceph_connection *con,
892 						int *auth_proto)
893 {
894 	struct ceph_auth_handshake *auth;
895 
896 	if (!con->ops->get_authorizer) {
897 		con->out_connect.authorizer_protocol = CEPH_AUTH_UNKNOWN;
898 		con->out_connect.authorizer_len = 0;
899 		return NULL;
900 	}
901 
902 	/* Can't hold the mutex while getting authorizer */
903 	mutex_unlock(&con->mutex);
904 	auth = con->ops->get_authorizer(con, auth_proto, con->auth_retry);
905 	mutex_lock(&con->mutex);
906 
907 	if (IS_ERR(auth))
908 		return auth;
909 	if (con->state != CON_STATE_NEGOTIATING)
910 		return ERR_PTR(-EAGAIN);
911 
912 	con->auth_reply_buf = auth->authorizer_reply_buf;
913 	con->auth_reply_buf_len = auth->authorizer_reply_buf_len;
914 	return auth;
915 }
916 
917 /*
918  * We connected to a peer and are saying hello.
919  */
920 static void prepare_write_banner(struct ceph_connection *con)
921 {
922 	con_out_kvec_add(con, strlen(CEPH_BANNER), CEPH_BANNER);
923 	con_out_kvec_add(con, sizeof (con->msgr->my_enc_addr),
924 					&con->msgr->my_enc_addr);
925 
926 	con->out_more = 0;
927 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
928 }
929 
930 static int prepare_write_connect(struct ceph_connection *con)
931 {
932 	unsigned int global_seq = get_global_seq(con->msgr, 0);
933 	int proto;
934 	int auth_proto;
935 	struct ceph_auth_handshake *auth;
936 
937 	switch (con->peer_name.type) {
938 	case CEPH_ENTITY_TYPE_MON:
939 		proto = CEPH_MONC_PROTOCOL;
940 		break;
941 	case CEPH_ENTITY_TYPE_OSD:
942 		proto = CEPH_OSDC_PROTOCOL;
943 		break;
944 	case CEPH_ENTITY_TYPE_MDS:
945 		proto = CEPH_MDSC_PROTOCOL;
946 		break;
947 	default:
948 		BUG();
949 	}
950 
951 	dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
952 	     con->connect_seq, global_seq, proto);
953 
954 	con->out_connect.features = cpu_to_le64(con->msgr->supported_features);
955 	con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
956 	con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
957 	con->out_connect.global_seq = cpu_to_le32(global_seq);
958 	con->out_connect.protocol_version = cpu_to_le32(proto);
959 	con->out_connect.flags = 0;
960 
961 	auth_proto = CEPH_AUTH_UNKNOWN;
962 	auth = get_connect_authorizer(con, &auth_proto);
963 	if (IS_ERR(auth))
964 		return PTR_ERR(auth);
965 
966 	con->out_connect.authorizer_protocol = cpu_to_le32(auth_proto);
967 	con->out_connect.authorizer_len = auth ?
968 		cpu_to_le32(auth->authorizer_buf_len) : 0;
969 
970 	con_out_kvec_add(con, sizeof (con->out_connect),
971 					&con->out_connect);
972 	if (auth && auth->authorizer_buf_len)
973 		con_out_kvec_add(con, auth->authorizer_buf_len,
974 					auth->authorizer_buf);
975 
976 	con->out_more = 0;
977 	con_flag_set(con, CON_FLAG_WRITE_PENDING);
978 
979 	return 0;
980 }
981 
982 /*
983  * write as much of pending kvecs to the socket as we can.
984  *  1 -> done
985  *  0 -> socket full, but more to do
986  * <0 -> error
987  */
988 static int write_partial_kvec(struct ceph_connection *con)
989 {
990 	int ret;
991 
992 	dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
993 	while (con->out_kvec_bytes > 0) {
994 		ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
995 				       con->out_kvec_left, con->out_kvec_bytes,
996 				       con->out_more);
997 		if (ret <= 0)
998 			goto out;
999 		con->out_kvec_bytes -= ret;
1000 		if (con->out_kvec_bytes == 0)
1001 			break;            /* done */
1002 
1003 		/* account for full iov entries consumed */
1004 		while (ret >= con->out_kvec_cur->iov_len) {
1005 			BUG_ON(!con->out_kvec_left);
1006 			ret -= con->out_kvec_cur->iov_len;
1007 			con->out_kvec_cur++;
1008 			con->out_kvec_left--;
1009 		}
1010 		/* and for a partially-consumed entry */
1011 		if (ret) {
1012 			con->out_kvec_cur->iov_len -= ret;
1013 			con->out_kvec_cur->iov_base += ret;
1014 		}
1015 	}
1016 	con->out_kvec_left = 0;
1017 	con->out_kvec_is_msg = false;
1018 	ret = 1;
1019 out:
1020 	dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
1021 	     con->out_kvec_bytes, con->out_kvec_left, ret);
1022 	return ret;  /* done! */
1023 }
1024 
1025 static void out_msg_pos_next(struct ceph_connection *con, struct page *page,
1026 			size_t len, size_t sent, bool in_trail)
1027 {
1028 	struct ceph_msg *msg = con->out_msg;
1029 
1030 	BUG_ON(!msg);
1031 	BUG_ON(!sent);
1032 
1033 	con->out_msg_pos.data_pos += sent;
1034 	con->out_msg_pos.page_pos += sent;
1035 	if (sent < len)
1036 		return;
1037 
1038 	BUG_ON(sent != len);
1039 	con->out_msg_pos.page_pos = 0;
1040 	con->out_msg_pos.page++;
1041 	con->out_msg_pos.did_page_crc = false;
1042 	if (in_trail)
1043 		list_move_tail(&page->lru,
1044 			       &msg->trail->head);
1045 	else if (msg->pagelist)
1046 		list_move_tail(&page->lru,
1047 			       &msg->pagelist->head);
1048 #ifdef CONFIG_BLOCK
1049 	else if (msg->bio)
1050 		iter_bio_next(&msg->bio_iter, &msg->bio_seg);
1051 #endif
1052 }
1053 
1054 /*
1055  * Write as much message data payload as we can.  If we finish, queue
1056  * up the footer.
1057  *  1 -> done, footer is now queued in out_kvec[].
1058  *  0 -> socket full, but more to do
1059  * <0 -> error
1060  */
1061 static int write_partial_msg_pages(struct ceph_connection *con)
1062 {
1063 	struct ceph_msg *msg = con->out_msg;
1064 	unsigned int data_len = le32_to_cpu(msg->hdr.data_len);
1065 	size_t len;
1066 	bool do_datacrc = !con->msgr->nocrc;
1067 	int ret;
1068 	int total_max_write;
1069 	bool in_trail = false;
1070 	const size_t trail_len = (msg->trail ? msg->trail->length : 0);
1071 	const size_t trail_off = data_len - trail_len;
1072 
1073 	dout("write_partial_msg_pages %p msg %p page %d/%d offset %d\n",
1074 	     con, msg, con->out_msg_pos.page, msg->nr_pages,
1075 	     con->out_msg_pos.page_pos);
1076 
1077 	/*
1078 	 * Iterate through each page that contains data to be
1079 	 * written, and send as much as possible for each.
1080 	 *
1081 	 * If we are calculating the data crc (the default), we will
1082 	 * need to map the page.  If we have no pages, they have
1083 	 * been revoked, so use the zero page.
1084 	 */
1085 	while (data_len > con->out_msg_pos.data_pos) {
1086 		struct page *page = NULL;
1087 		int max_write = PAGE_SIZE;
1088 		int bio_offset = 0;
1089 
1090 		in_trail = in_trail || con->out_msg_pos.data_pos >= trail_off;
1091 		if (!in_trail)
1092 			total_max_write = trail_off - con->out_msg_pos.data_pos;
1093 
1094 		if (in_trail) {
1095 			total_max_write = data_len - con->out_msg_pos.data_pos;
1096 
1097 			page = list_first_entry(&msg->trail->head,
1098 						struct page, lru);
1099 		} else if (msg->pages) {
1100 			page = msg->pages[con->out_msg_pos.page];
1101 		} else if (msg->pagelist) {
1102 			page = list_first_entry(&msg->pagelist->head,
1103 						struct page, lru);
1104 #ifdef CONFIG_BLOCK
1105 		} else if (msg->bio) {
1106 			struct bio_vec *bv;
1107 
1108 			bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg);
1109 			page = bv->bv_page;
1110 			bio_offset = bv->bv_offset;
1111 			max_write = bv->bv_len;
1112 #endif
1113 		} else {
1114 			page = zero_page;
1115 		}
1116 		len = min_t(int, max_write - con->out_msg_pos.page_pos,
1117 			    total_max_write);
1118 
1119 		if (do_datacrc && !con->out_msg_pos.did_page_crc) {
1120 			void *base;
1121 			u32 crc = le32_to_cpu(msg->footer.data_crc);
1122 			char *kaddr;
1123 
1124 			kaddr = kmap(page);
1125 			BUG_ON(kaddr == NULL);
1126 			base = kaddr + con->out_msg_pos.page_pos + bio_offset;
1127 			crc = crc32c(crc, base, len);
1128 			kunmap(page);
1129 			msg->footer.data_crc = cpu_to_le32(crc);
1130 			con->out_msg_pos.did_page_crc = true;
1131 		}
1132 		ret = ceph_tcp_sendpage(con->sock, page,
1133 				      con->out_msg_pos.page_pos + bio_offset,
1134 				      len, 1);
1135 		if (ret <= 0)
1136 			goto out;
1137 
1138 		out_msg_pos_next(con, page, len, (size_t) ret, in_trail);
1139 	}
1140 
1141 	dout("write_partial_msg_pages %p msg %p done\n", con, msg);
1142 
1143 	/* prepare and queue up footer, too */
1144 	if (!do_datacrc)
1145 		msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
1146 	con_out_kvec_reset(con);
1147 	prepare_write_message_footer(con);
1148 	ret = 1;
1149 out:
1150 	return ret;
1151 }
1152 
1153 /*
1154  * write some zeros
1155  */
1156 static int write_partial_skip(struct ceph_connection *con)
1157 {
1158 	int ret;
1159 
1160 	while (con->out_skip > 0) {
1161 		size_t size = min(con->out_skip, (int) PAGE_CACHE_SIZE);
1162 
1163 		ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, 1);
1164 		if (ret <= 0)
1165 			goto out;
1166 		con->out_skip -= ret;
1167 	}
1168 	ret = 1;
1169 out:
1170 	return ret;
1171 }
1172 
1173 /*
1174  * Prepare to read connection handshake, or an ack.
1175  */
1176 static void prepare_read_banner(struct ceph_connection *con)
1177 {
1178 	dout("prepare_read_banner %p\n", con);
1179 	con->in_base_pos = 0;
1180 }
1181 
1182 static void prepare_read_connect(struct ceph_connection *con)
1183 {
1184 	dout("prepare_read_connect %p\n", con);
1185 	con->in_base_pos = 0;
1186 }
1187 
1188 static void prepare_read_ack(struct ceph_connection *con)
1189 {
1190 	dout("prepare_read_ack %p\n", con);
1191 	con->in_base_pos = 0;
1192 }
1193 
1194 static void prepare_read_tag(struct ceph_connection *con)
1195 {
1196 	dout("prepare_read_tag %p\n", con);
1197 	con->in_base_pos = 0;
1198 	con->in_tag = CEPH_MSGR_TAG_READY;
1199 }
1200 
1201 /*
1202  * Prepare to read a message.
1203  */
1204 static int prepare_read_message(struct ceph_connection *con)
1205 {
1206 	dout("prepare_read_message %p\n", con);
1207 	BUG_ON(con->in_msg != NULL);
1208 	con->in_base_pos = 0;
1209 	con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
1210 	return 0;
1211 }
1212 
1213 
1214 static int read_partial(struct ceph_connection *con,
1215 			int end, int size, void *object)
1216 {
1217 	while (con->in_base_pos < end) {
1218 		int left = end - con->in_base_pos;
1219 		int have = size - left;
1220 		int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
1221 		if (ret <= 0)
1222 			return ret;
1223 		con->in_base_pos += ret;
1224 	}
1225 	return 1;
1226 }
1227 
1228 
1229 /*
1230  * Read all or part of the connect-side handshake on a new connection
1231  */
1232 static int read_partial_banner(struct ceph_connection *con)
1233 {
1234 	int size;
1235 	int end;
1236 	int ret;
1237 
1238 	dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
1239 
1240 	/* peer's banner */
1241 	size = strlen(CEPH_BANNER);
1242 	end = size;
1243 	ret = read_partial(con, end, size, con->in_banner);
1244 	if (ret <= 0)
1245 		goto out;
1246 
1247 	size = sizeof (con->actual_peer_addr);
1248 	end += size;
1249 	ret = read_partial(con, end, size, &con->actual_peer_addr);
1250 	if (ret <= 0)
1251 		goto out;
1252 
1253 	size = sizeof (con->peer_addr_for_me);
1254 	end += size;
1255 	ret = read_partial(con, end, size, &con->peer_addr_for_me);
1256 	if (ret <= 0)
1257 		goto out;
1258 
1259 out:
1260 	return ret;
1261 }
1262 
1263 static int read_partial_connect(struct ceph_connection *con)
1264 {
1265 	int size;
1266 	int end;
1267 	int ret;
1268 
1269 	dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
1270 
1271 	size = sizeof (con->in_reply);
1272 	end = size;
1273 	ret = read_partial(con, end, size, &con->in_reply);
1274 	if (ret <= 0)
1275 		goto out;
1276 
1277 	size = le32_to_cpu(con->in_reply.authorizer_len);
1278 	end += size;
1279 	ret = read_partial(con, end, size, con->auth_reply_buf);
1280 	if (ret <= 0)
1281 		goto out;
1282 
1283 	dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
1284 	     con, (int)con->in_reply.tag,
1285 	     le32_to_cpu(con->in_reply.connect_seq),
1286 	     le32_to_cpu(con->in_reply.global_seq));
1287 out:
1288 	return ret;
1289 
1290 }
1291 
1292 /*
1293  * Verify the hello banner looks okay.
1294  */
1295 static int verify_hello(struct ceph_connection *con)
1296 {
1297 	if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
1298 		pr_err("connect to %s got bad banner\n",
1299 		       ceph_pr_addr(&con->peer_addr.in_addr));
1300 		con->error_msg = "protocol error, bad banner";
1301 		return -1;
1302 	}
1303 	return 0;
1304 }
1305 
1306 static bool addr_is_blank(struct sockaddr_storage *ss)
1307 {
1308 	switch (ss->ss_family) {
1309 	case AF_INET:
1310 		return ((struct sockaddr_in *)ss)->sin_addr.s_addr == 0;
1311 	case AF_INET6:
1312 		return
1313 		     ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[0] == 0 &&
1314 		     ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[1] == 0 &&
1315 		     ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[2] == 0 &&
1316 		     ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[3] == 0;
1317 	}
1318 	return false;
1319 }
1320 
1321 static int addr_port(struct sockaddr_storage *ss)
1322 {
1323 	switch (ss->ss_family) {
1324 	case AF_INET:
1325 		return ntohs(((struct sockaddr_in *)ss)->sin_port);
1326 	case AF_INET6:
1327 		return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
1328 	}
1329 	return 0;
1330 }
1331 
1332 static void addr_set_port(struct sockaddr_storage *ss, int p)
1333 {
1334 	switch (ss->ss_family) {
1335 	case AF_INET:
1336 		((struct sockaddr_in *)ss)->sin_port = htons(p);
1337 		break;
1338 	case AF_INET6:
1339 		((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
1340 		break;
1341 	}
1342 }
1343 
1344 /*
1345  * Unlike other *_pton function semantics, zero indicates success.
1346  */
1347 static int ceph_pton(const char *str, size_t len, struct sockaddr_storage *ss,
1348 		char delim, const char **ipend)
1349 {
1350 	struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
1351 	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
1352 
1353 	memset(ss, 0, sizeof(*ss));
1354 
1355 	if (in4_pton(str, len, (u8 *)&in4->sin_addr.s_addr, delim, ipend)) {
1356 		ss->ss_family = AF_INET;
1357 		return 0;
1358 	}
1359 
1360 	if (in6_pton(str, len, (u8 *)&in6->sin6_addr.s6_addr, delim, ipend)) {
1361 		ss->ss_family = AF_INET6;
1362 		return 0;
1363 	}
1364 
1365 	return -EINVAL;
1366 }
1367 
1368 /*
1369  * Extract hostname string and resolve using kernel DNS facility.
1370  */
1371 #ifdef CONFIG_CEPH_LIB_USE_DNS_RESOLVER
1372 static int ceph_dns_resolve_name(const char *name, size_t namelen,
1373 		struct sockaddr_storage *ss, char delim, const char **ipend)
1374 {
1375 	const char *end, *delim_p;
1376 	char *colon_p, *ip_addr = NULL;
1377 	int ip_len, ret;
1378 
1379 	/*
1380 	 * The end of the hostname occurs immediately preceding the delimiter or
1381 	 * the port marker (':') where the delimiter takes precedence.
1382 	 */
1383 	delim_p = memchr(name, delim, namelen);
1384 	colon_p = memchr(name, ':', namelen);
1385 
1386 	if (delim_p && colon_p)
1387 		end = delim_p < colon_p ? delim_p : colon_p;
1388 	else if (!delim_p && colon_p)
1389 		end = colon_p;
1390 	else {
1391 		end = delim_p;
1392 		if (!end) /* case: hostname:/ */
1393 			end = name + namelen;
1394 	}
1395 
1396 	if (end <= name)
1397 		return -EINVAL;
1398 
1399 	/* do dns_resolve upcall */
1400 	ip_len = dns_query(NULL, name, end - name, NULL, &ip_addr, NULL);
1401 	if (ip_len > 0)
1402 		ret = ceph_pton(ip_addr, ip_len, ss, -1, NULL);
1403 	else
1404 		ret = -ESRCH;
1405 
1406 	kfree(ip_addr);
1407 
1408 	*ipend = end;
1409 
1410 	pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name,
1411 			ret, ret ? "failed" : ceph_pr_addr(ss));
1412 
1413 	return ret;
1414 }
1415 #else
1416 static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
1417 		struct sockaddr_storage *ss, char delim, const char **ipend)
1418 {
1419 	return -EINVAL;
1420 }
1421 #endif
1422 
1423 /*
1424  * Parse a server name (IP or hostname). If a valid IP address is not found
1425  * then try to extract a hostname to resolve using userspace DNS upcall.
1426  */
1427 static int ceph_parse_server_name(const char *name, size_t namelen,
1428 			struct sockaddr_storage *ss, char delim, const char **ipend)
1429 {
1430 	int ret;
1431 
1432 	ret = ceph_pton(name, namelen, ss, delim, ipend);
1433 	if (ret)
1434 		ret = ceph_dns_resolve_name(name, namelen, ss, delim, ipend);
1435 
1436 	return ret;
1437 }
1438 
1439 /*
1440  * Parse an ip[:port] list into an addr array.  Use the default
1441  * monitor port if a port isn't specified.
1442  */
1443 int ceph_parse_ips(const char *c, const char *end,
1444 		   struct ceph_entity_addr *addr,
1445 		   int max_count, int *count)
1446 {
1447 	int i, ret = -EINVAL;
1448 	const char *p = c;
1449 
1450 	dout("parse_ips on '%.*s'\n", (int)(end-c), c);
1451 	for (i = 0; i < max_count; i++) {
1452 		const char *ipend;
1453 		struct sockaddr_storage *ss = &addr[i].in_addr;
1454 		int port;
1455 		char delim = ',';
1456 
1457 		if (*p == '[') {
1458 			delim = ']';
1459 			p++;
1460 		}
1461 
1462 		ret = ceph_parse_server_name(p, end - p, ss, delim, &ipend);
1463 		if (ret)
1464 			goto bad;
1465 		ret = -EINVAL;
1466 
1467 		p = ipend;
1468 
1469 		if (delim == ']') {
1470 			if (*p != ']') {
1471 				dout("missing matching ']'\n");
1472 				goto bad;
1473 			}
1474 			p++;
1475 		}
1476 
1477 		/* port? */
1478 		if (p < end && *p == ':') {
1479 			port = 0;
1480 			p++;
1481 			while (p < end && *p >= '0' && *p <= '9') {
1482 				port = (port * 10) + (*p - '0');
1483 				p++;
1484 			}
1485 			if (port > 65535 || port == 0)
1486 				goto bad;
1487 		} else {
1488 			port = CEPH_MON_PORT;
1489 		}
1490 
1491 		addr_set_port(ss, port);
1492 
1493 		dout("parse_ips got %s\n", ceph_pr_addr(ss));
1494 
1495 		if (p == end)
1496 			break;
1497 		if (*p != ',')
1498 			goto bad;
1499 		p++;
1500 	}
1501 
1502 	if (p != end)
1503 		goto bad;
1504 
1505 	if (count)
1506 		*count = i + 1;
1507 	return 0;
1508 
1509 bad:
1510 	pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c);
1511 	return ret;
1512 }
1513 EXPORT_SYMBOL(ceph_parse_ips);
1514 
1515 static int process_banner(struct ceph_connection *con)
1516 {
1517 	dout("process_banner on %p\n", con);
1518 
1519 	if (verify_hello(con) < 0)
1520 		return -1;
1521 
1522 	ceph_decode_addr(&con->actual_peer_addr);
1523 	ceph_decode_addr(&con->peer_addr_for_me);
1524 
1525 	/*
1526 	 * Make sure the other end is who we wanted.  note that the other
1527 	 * end may not yet know their ip address, so if it's 0.0.0.0, give
1528 	 * them the benefit of the doubt.
1529 	 */
1530 	if (memcmp(&con->peer_addr, &con->actual_peer_addr,
1531 		   sizeof(con->peer_addr)) != 0 &&
1532 	    !(addr_is_blank(&con->actual_peer_addr.in_addr) &&
1533 	      con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
1534 		pr_warning("wrong peer, want %s/%d, got %s/%d\n",
1535 			   ceph_pr_addr(&con->peer_addr.in_addr),
1536 			   (int)le32_to_cpu(con->peer_addr.nonce),
1537 			   ceph_pr_addr(&con->actual_peer_addr.in_addr),
1538 			   (int)le32_to_cpu(con->actual_peer_addr.nonce));
1539 		con->error_msg = "wrong peer at address";
1540 		return -1;
1541 	}
1542 
1543 	/*
1544 	 * did we learn our address?
1545 	 */
1546 	if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
1547 		int port = addr_port(&con->msgr->inst.addr.in_addr);
1548 
1549 		memcpy(&con->msgr->inst.addr.in_addr,
1550 		       &con->peer_addr_for_me.in_addr,
1551 		       sizeof(con->peer_addr_for_me.in_addr));
1552 		addr_set_port(&con->msgr->inst.addr.in_addr, port);
1553 		encode_my_addr(con->msgr);
1554 		dout("process_banner learned my addr is %s\n",
1555 		     ceph_pr_addr(&con->msgr->inst.addr.in_addr));
1556 	}
1557 
1558 	return 0;
1559 }
1560 
1561 static int process_connect(struct ceph_connection *con)
1562 {
1563 	u64 sup_feat = con->msgr->supported_features;
1564 	u64 req_feat = con->msgr->required_features;
1565 	u64 server_feat = le64_to_cpu(con->in_reply.features);
1566 	int ret;
1567 
1568 	dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
1569 
1570 	switch (con->in_reply.tag) {
1571 	case CEPH_MSGR_TAG_FEATURES:
1572 		pr_err("%s%lld %s feature set mismatch,"
1573 		       " my %llx < server's %llx, missing %llx\n",
1574 		       ENTITY_NAME(con->peer_name),
1575 		       ceph_pr_addr(&con->peer_addr.in_addr),
1576 		       sup_feat, server_feat, server_feat & ~sup_feat);
1577 		con->error_msg = "missing required protocol features";
1578 		reset_connection(con);
1579 		return -1;
1580 
1581 	case CEPH_MSGR_TAG_BADPROTOVER:
1582 		pr_err("%s%lld %s protocol version mismatch,"
1583 		       " my %d != server's %d\n",
1584 		       ENTITY_NAME(con->peer_name),
1585 		       ceph_pr_addr(&con->peer_addr.in_addr),
1586 		       le32_to_cpu(con->out_connect.protocol_version),
1587 		       le32_to_cpu(con->in_reply.protocol_version));
1588 		con->error_msg = "protocol version mismatch";
1589 		reset_connection(con);
1590 		return -1;
1591 
1592 	case CEPH_MSGR_TAG_BADAUTHORIZER:
1593 		con->auth_retry++;
1594 		dout("process_connect %p got BADAUTHORIZER attempt %d\n", con,
1595 		     con->auth_retry);
1596 		if (con->auth_retry == 2) {
1597 			con->error_msg = "connect authorization failure";
1598 			return -1;
1599 		}
1600 		con->auth_retry = 1;
1601 		con_out_kvec_reset(con);
1602 		ret = prepare_write_connect(con);
1603 		if (ret < 0)
1604 			return ret;
1605 		prepare_read_connect(con);
1606 		break;
1607 
1608 	case CEPH_MSGR_TAG_RESETSESSION:
1609 		/*
1610 		 * If we connected with a large connect_seq but the peer
1611 		 * has no record of a session with us (no connection, or
1612 		 * connect_seq == 0), they will send RESETSESION to indicate
1613 		 * that they must have reset their session, and may have
1614 		 * dropped messages.
1615 		 */
1616 		dout("process_connect got RESET peer seq %u\n",
1617 		     le32_to_cpu(con->in_reply.connect_seq));
1618 		pr_err("%s%lld %s connection reset\n",
1619 		       ENTITY_NAME(con->peer_name),
1620 		       ceph_pr_addr(&con->peer_addr.in_addr));
1621 		reset_connection(con);
1622 		con_out_kvec_reset(con);
1623 		ret = prepare_write_connect(con);
1624 		if (ret < 0)
1625 			return ret;
1626 		prepare_read_connect(con);
1627 
1628 		/* Tell ceph about it. */
1629 		mutex_unlock(&con->mutex);
1630 		pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));
1631 		if (con->ops->peer_reset)
1632 			con->ops->peer_reset(con);
1633 		mutex_lock(&con->mutex);
1634 		if (con->state != CON_STATE_NEGOTIATING)
1635 			return -EAGAIN;
1636 		break;
1637 
1638 	case CEPH_MSGR_TAG_RETRY_SESSION:
1639 		/*
1640 		 * If we sent a smaller connect_seq than the peer has, try
1641 		 * again with a larger value.
1642 		 */
1643 		dout("process_connect got RETRY_SESSION my seq %u, peer %u\n",
1644 		     le32_to_cpu(con->out_connect.connect_seq),
1645 		     le32_to_cpu(con->in_reply.connect_seq));
1646 		con->connect_seq = le32_to_cpu(con->in_reply.connect_seq);
1647 		con_out_kvec_reset(con);
1648 		ret = prepare_write_connect(con);
1649 		if (ret < 0)
1650 			return ret;
1651 		prepare_read_connect(con);
1652 		break;
1653 
1654 	case CEPH_MSGR_TAG_RETRY_GLOBAL:
1655 		/*
1656 		 * If we sent a smaller global_seq than the peer has, try
1657 		 * again with a larger value.
1658 		 */
1659 		dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
1660 		     con->peer_global_seq,
1661 		     le32_to_cpu(con->in_reply.global_seq));
1662 		get_global_seq(con->msgr,
1663 			       le32_to_cpu(con->in_reply.global_seq));
1664 		con_out_kvec_reset(con);
1665 		ret = prepare_write_connect(con);
1666 		if (ret < 0)
1667 			return ret;
1668 		prepare_read_connect(con);
1669 		break;
1670 
1671 	case CEPH_MSGR_TAG_READY:
1672 		if (req_feat & ~server_feat) {
1673 			pr_err("%s%lld %s protocol feature mismatch,"
1674 			       " my required %llx > server's %llx, need %llx\n",
1675 			       ENTITY_NAME(con->peer_name),
1676 			       ceph_pr_addr(&con->peer_addr.in_addr),
1677 			       req_feat, server_feat, req_feat & ~server_feat);
1678 			con->error_msg = "missing required protocol features";
1679 			reset_connection(con);
1680 			return -1;
1681 		}
1682 
1683 		WARN_ON(con->state != CON_STATE_NEGOTIATING);
1684 		con->state = CON_STATE_OPEN;
1685 
1686 		con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
1687 		con->connect_seq++;
1688 		con->peer_features = server_feat;
1689 		dout("process_connect got READY gseq %d cseq %d (%d)\n",
1690 		     con->peer_global_seq,
1691 		     le32_to_cpu(con->in_reply.connect_seq),
1692 		     con->connect_seq);
1693 		WARN_ON(con->connect_seq !=
1694 			le32_to_cpu(con->in_reply.connect_seq));
1695 
1696 		if (con->in_reply.flags & CEPH_MSG_CONNECT_LOSSY)
1697 			con_flag_set(con, CON_FLAG_LOSSYTX);
1698 
1699 		con->delay = 0;      /* reset backoff memory */
1700 
1701 		prepare_read_tag(con);
1702 		break;
1703 
1704 	case CEPH_MSGR_TAG_WAIT:
1705 		/*
1706 		 * If there is a connection race (we are opening
1707 		 * connections to each other), one of us may just have
1708 		 * to WAIT.  This shouldn't happen if we are the
1709 		 * client.
1710 		 */
1711 		pr_err("process_connect got WAIT as client\n");
1712 		con->error_msg = "protocol error, got WAIT as client";
1713 		return -1;
1714 
1715 	default:
1716 		pr_err("connect protocol error, will retry\n");
1717 		con->error_msg = "protocol error, garbage tag during connect";
1718 		return -1;
1719 	}
1720 	return 0;
1721 }
1722 
1723 
1724 /*
1725  * read (part of) an ack
1726  */
1727 static int read_partial_ack(struct ceph_connection *con)
1728 {
1729 	int size = sizeof (con->in_temp_ack);
1730 	int end = size;
1731 
1732 	return read_partial(con, end, size, &con->in_temp_ack);
1733 }
1734 
1735 
1736 /*
1737  * We can finally discard anything that's been acked.
1738  */
1739 static void process_ack(struct ceph_connection *con)
1740 {
1741 	struct ceph_msg *m;
1742 	u64 ack = le64_to_cpu(con->in_temp_ack);
1743 	u64 seq;
1744 
1745 	while (!list_empty(&con->out_sent)) {
1746 		m = list_first_entry(&con->out_sent, struct ceph_msg,
1747 				     list_head);
1748 		seq = le64_to_cpu(m->hdr.seq);
1749 		if (seq > ack)
1750 			break;
1751 		dout("got ack for seq %llu type %d at %p\n", seq,
1752 		     le16_to_cpu(m->hdr.type), m);
1753 		m->ack_stamp = jiffies;
1754 		ceph_msg_remove(m);
1755 	}
1756 	prepare_read_tag(con);
1757 }
1758 
1759 
1760 
1761 
1762 static int read_partial_message_section(struct ceph_connection *con,
1763 					struct kvec *section,
1764 					unsigned int sec_len, u32 *crc)
1765 {
1766 	int ret, left;
1767 
1768 	BUG_ON(!section);
1769 
1770 	while (section->iov_len < sec_len) {
1771 		BUG_ON(section->iov_base == NULL);
1772 		left = sec_len - section->iov_len;
1773 		ret = ceph_tcp_recvmsg(con->sock, (char *)section->iov_base +
1774 				       section->iov_len, left);
1775 		if (ret <= 0)
1776 			return ret;
1777 		section->iov_len += ret;
1778 	}
1779 	if (section->iov_len == sec_len)
1780 		*crc = crc32c(0, section->iov_base, section->iov_len);
1781 
1782 	return 1;
1783 }
1784 
1785 static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip);
1786 
1787 static int read_partial_message_pages(struct ceph_connection *con,
1788 				      struct page **pages,
1789 				      unsigned int data_len, bool do_datacrc)
1790 {
1791 	void *p;
1792 	int ret;
1793 	int left;
1794 
1795 	left = min((int)(data_len - con->in_msg_pos.data_pos),
1796 		   (int)(PAGE_SIZE - con->in_msg_pos.page_pos));
1797 	/* (page) data */
1798 	BUG_ON(pages == NULL);
1799 	p = kmap(pages[con->in_msg_pos.page]);
1800 	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
1801 			       left);
1802 	if (ret > 0 && do_datacrc)
1803 		con->in_data_crc =
1804 			crc32c(con->in_data_crc,
1805 				  p + con->in_msg_pos.page_pos, ret);
1806 	kunmap(pages[con->in_msg_pos.page]);
1807 	if (ret <= 0)
1808 		return ret;
1809 	con->in_msg_pos.data_pos += ret;
1810 	con->in_msg_pos.page_pos += ret;
1811 	if (con->in_msg_pos.page_pos == PAGE_SIZE) {
1812 		con->in_msg_pos.page_pos = 0;
1813 		con->in_msg_pos.page++;
1814 	}
1815 
1816 	return ret;
1817 }
1818 
1819 #ifdef CONFIG_BLOCK
1820 static int read_partial_message_bio(struct ceph_connection *con,
1821 				    struct bio **bio_iter, int *bio_seg,
1822 				    unsigned int data_len, bool do_datacrc)
1823 {
1824 	struct bio_vec *bv = bio_iovec_idx(*bio_iter, *bio_seg);
1825 	void *p;
1826 	int ret, left;
1827 
1828 	left = min((int)(data_len - con->in_msg_pos.data_pos),
1829 		   (int)(bv->bv_len - con->in_msg_pos.page_pos));
1830 
1831 	p = kmap(bv->bv_page) + bv->bv_offset;
1832 
1833 	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
1834 			       left);
1835 	if (ret > 0 && do_datacrc)
1836 		con->in_data_crc =
1837 			crc32c(con->in_data_crc,
1838 				  p + con->in_msg_pos.page_pos, ret);
1839 	kunmap(bv->bv_page);
1840 	if (ret <= 0)
1841 		return ret;
1842 	con->in_msg_pos.data_pos += ret;
1843 	con->in_msg_pos.page_pos += ret;
1844 	if (con->in_msg_pos.page_pos == bv->bv_len) {
1845 		con->in_msg_pos.page_pos = 0;
1846 		iter_bio_next(bio_iter, bio_seg);
1847 	}
1848 
1849 	return ret;
1850 }
1851 #endif
1852 
1853 /*
1854  * read (part of) a message.
1855  */
1856 static int read_partial_message(struct ceph_connection *con)
1857 {
1858 	struct ceph_msg *m = con->in_msg;
1859 	int size;
1860 	int end;
1861 	int ret;
1862 	unsigned int front_len, middle_len, data_len;
1863 	bool do_datacrc = !con->msgr->nocrc;
1864 	u64 seq;
1865 	u32 crc;
1866 
1867 	dout("read_partial_message con %p msg %p\n", con, m);
1868 
1869 	/* header */
1870 	size = sizeof (con->in_hdr);
1871 	end = size;
1872 	ret = read_partial(con, end, size, &con->in_hdr);
1873 	if (ret <= 0)
1874 		return ret;
1875 
1876 	crc = crc32c(0, &con->in_hdr, offsetof(struct ceph_msg_header, crc));
1877 	if (cpu_to_le32(crc) != con->in_hdr.crc) {
1878 		pr_err("read_partial_message bad hdr "
1879 		       " crc %u != expected %u\n",
1880 		       crc, con->in_hdr.crc);
1881 		return -EBADMSG;
1882 	}
1883 
1884 	front_len = le32_to_cpu(con->in_hdr.front_len);
1885 	if (front_len > CEPH_MSG_MAX_FRONT_LEN)
1886 		return -EIO;
1887 	middle_len = le32_to_cpu(con->in_hdr.middle_len);
1888 	if (middle_len > CEPH_MSG_MAX_DATA_LEN)
1889 		return -EIO;
1890 	data_len = le32_to_cpu(con->in_hdr.data_len);
1891 	if (data_len > CEPH_MSG_MAX_DATA_LEN)
1892 		return -EIO;
1893 
1894 	/* verify seq# */
1895 	seq = le64_to_cpu(con->in_hdr.seq);
1896 	if ((s64)seq - (s64)con->in_seq < 1) {
1897 		pr_info("skipping %s%lld %s seq %lld expected %lld\n",
1898 			ENTITY_NAME(con->peer_name),
1899 			ceph_pr_addr(&con->peer_addr.in_addr),
1900 			seq, con->in_seq + 1);
1901 		con->in_base_pos = -front_len - middle_len - data_len -
1902 			sizeof(m->footer);
1903 		con->in_tag = CEPH_MSGR_TAG_READY;
1904 		return 0;
1905 	} else if ((s64)seq - (s64)con->in_seq > 1) {
1906 		pr_err("read_partial_message bad seq %lld expected %lld\n",
1907 		       seq, con->in_seq + 1);
1908 		con->error_msg = "bad message sequence # for incoming message";
1909 		return -EBADMSG;
1910 	}
1911 
1912 	/* allocate message? */
1913 	if (!con->in_msg) {
1914 		int skip = 0;
1915 
1916 		dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
1917 		     con->in_hdr.front_len, con->in_hdr.data_len);
1918 		ret = ceph_con_in_msg_alloc(con, &skip);
1919 		if (ret < 0)
1920 			return ret;
1921 		if (skip) {
1922 			/* skip this message */
1923 			dout("alloc_msg said skip message\n");
1924 			BUG_ON(con->in_msg);
1925 			con->in_base_pos = -front_len - middle_len - data_len -
1926 				sizeof(m->footer);
1927 			con->in_tag = CEPH_MSGR_TAG_READY;
1928 			con->in_seq++;
1929 			return 0;
1930 		}
1931 
1932 		BUG_ON(!con->in_msg);
1933 		BUG_ON(con->in_msg->con != con);
1934 		m = con->in_msg;
1935 		m->front.iov_len = 0;    /* haven't read it yet */
1936 		if (m->middle)
1937 			m->middle->vec.iov_len = 0;
1938 
1939 		con->in_msg_pos.page = 0;
1940 		if (m->pages)
1941 			con->in_msg_pos.page_pos = m->page_alignment;
1942 		else
1943 			con->in_msg_pos.page_pos = 0;
1944 		con->in_msg_pos.data_pos = 0;
1945 
1946 #ifdef CONFIG_BLOCK
1947 		if (m->bio)
1948 			init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg);
1949 #endif
1950 	}
1951 
1952 	/* front */
1953 	ret = read_partial_message_section(con, &m->front, front_len,
1954 					   &con->in_front_crc);
1955 	if (ret <= 0)
1956 		return ret;
1957 
1958 	/* middle */
1959 	if (m->middle) {
1960 		ret = read_partial_message_section(con, &m->middle->vec,
1961 						   middle_len,
1962 						   &con->in_middle_crc);
1963 		if (ret <= 0)
1964 			return ret;
1965 	}
1966 
1967 	/* (page) data */
1968 	while (con->in_msg_pos.data_pos < data_len) {
1969 		if (m->pages) {
1970 			ret = read_partial_message_pages(con, m->pages,
1971 						 data_len, do_datacrc);
1972 			if (ret <= 0)
1973 				return ret;
1974 #ifdef CONFIG_BLOCK
1975 		} else if (m->bio) {
1976 			BUG_ON(!m->bio_iter);
1977 			ret = read_partial_message_bio(con,
1978 						 &m->bio_iter, &m->bio_seg,
1979 						 data_len, do_datacrc);
1980 			if (ret <= 0)
1981 				return ret;
1982 #endif
1983 		} else {
1984 			BUG_ON(1);
1985 		}
1986 	}
1987 
1988 	/* footer */
1989 	size = sizeof (m->footer);
1990 	end += size;
1991 	ret = read_partial(con, end, size, &m->footer);
1992 	if (ret <= 0)
1993 		return ret;
1994 
1995 	dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
1996 	     m, front_len, m->footer.front_crc, middle_len,
1997 	     m->footer.middle_crc, data_len, m->footer.data_crc);
1998 
1999 	/* crc ok? */
2000 	if (con->in_front_crc != le32_to_cpu(m->footer.front_crc)) {
2001 		pr_err("read_partial_message %p front crc %u != exp. %u\n",
2002 		       m, con->in_front_crc, m->footer.front_crc);
2003 		return -EBADMSG;
2004 	}
2005 	if (con->in_middle_crc != le32_to_cpu(m->footer.middle_crc)) {
2006 		pr_err("read_partial_message %p middle crc %u != exp %u\n",
2007 		       m, con->in_middle_crc, m->footer.middle_crc);
2008 		return -EBADMSG;
2009 	}
2010 	if (do_datacrc &&
2011 	    (m->footer.flags & CEPH_MSG_FOOTER_NOCRC) == 0 &&
2012 	    con->in_data_crc != le32_to_cpu(m->footer.data_crc)) {
2013 		pr_err("read_partial_message %p data crc %u != exp. %u\n", m,
2014 		       con->in_data_crc, le32_to_cpu(m->footer.data_crc));
2015 		return -EBADMSG;
2016 	}
2017 
2018 	return 1; /* done! */
2019 }
2020 
2021 /*
2022  * Process message.  This happens in the worker thread.  The callback should
2023  * be careful not to do anything that waits on other incoming messages or it
2024  * may deadlock.
2025  */
2026 static void process_message(struct ceph_connection *con)
2027 {
2028 	struct ceph_msg *msg;
2029 
2030 	BUG_ON(con->in_msg->con != con);
2031 	con->in_msg->con = NULL;
2032 	msg = con->in_msg;
2033 	con->in_msg = NULL;
2034 	con->ops->put(con);
2035 
2036 	/* if first message, set peer_name */
2037 	if (con->peer_name.type == 0)
2038 		con->peer_name = msg->hdr.src;
2039 
2040 	con->in_seq++;
2041 	mutex_unlock(&con->mutex);
2042 
2043 	dout("===== %p %llu from %s%lld %d=%s len %d+%d (%u %u %u) =====\n",
2044 	     msg, le64_to_cpu(msg->hdr.seq),
2045 	     ENTITY_NAME(msg->hdr.src),
2046 	     le16_to_cpu(msg->hdr.type),
2047 	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
2048 	     le32_to_cpu(msg->hdr.front_len),
2049 	     le32_to_cpu(msg->hdr.data_len),
2050 	     con->in_front_crc, con->in_middle_crc, con->in_data_crc);
2051 	con->ops->dispatch(con, msg);
2052 
2053 	mutex_lock(&con->mutex);
2054 }
2055 
2056 
2057 /*
2058  * Write something to the socket.  Called in a worker thread when the
2059  * socket appears to be writeable and we have something ready to send.
2060  */
2061 static int try_write(struct ceph_connection *con)
2062 {
2063 	int ret = 1;
2064 
2065 	dout("try_write start %p state %lu\n", con, con->state);
2066 
2067 more:
2068 	dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
2069 
2070 	/* open the socket first? */
2071 	if (con->state == CON_STATE_PREOPEN) {
2072 		BUG_ON(con->sock);
2073 		con->state = CON_STATE_CONNECTING;
2074 
2075 		con_out_kvec_reset(con);
2076 		prepare_write_banner(con);
2077 		prepare_read_banner(con);
2078 
2079 		BUG_ON(con->in_msg);
2080 		con->in_tag = CEPH_MSGR_TAG_READY;
2081 		dout("try_write initiating connect on %p new state %lu\n",
2082 		     con, con->state);
2083 		ret = ceph_tcp_connect(con);
2084 		if (ret < 0) {
2085 			con->error_msg = "connect error";
2086 			goto out;
2087 		}
2088 	}
2089 
2090 more_kvec:
2091 	/* kvec data queued? */
2092 	if (con->out_skip) {
2093 		ret = write_partial_skip(con);
2094 		if (ret <= 0)
2095 			goto out;
2096 	}
2097 	if (con->out_kvec_left) {
2098 		ret = write_partial_kvec(con);
2099 		if (ret <= 0)
2100 			goto out;
2101 	}
2102 
2103 	/* msg pages? */
2104 	if (con->out_msg) {
2105 		if (con->out_msg_done) {
2106 			ceph_msg_put(con->out_msg);
2107 			con->out_msg = NULL;   /* we're done with this one */
2108 			goto do_next;
2109 		}
2110 
2111 		ret = write_partial_msg_pages(con);
2112 		if (ret == 1)
2113 			goto more_kvec;  /* we need to send the footer, too! */
2114 		if (ret == 0)
2115 			goto out;
2116 		if (ret < 0) {
2117 			dout("try_write write_partial_msg_pages err %d\n",
2118 			     ret);
2119 			goto out;
2120 		}
2121 	}
2122 
2123 do_next:
2124 	if (con->state == CON_STATE_OPEN) {
2125 		/* is anything else pending? */
2126 		if (!list_empty(&con->out_queue)) {
2127 			prepare_write_message(con);
2128 			goto more;
2129 		}
2130 		if (con->in_seq > con->in_seq_acked) {
2131 			prepare_write_ack(con);
2132 			goto more;
2133 		}
2134 		if (con_flag_test_and_clear(con, CON_FLAG_KEEPALIVE_PENDING)) {
2135 			prepare_write_keepalive(con);
2136 			goto more;
2137 		}
2138 	}
2139 
2140 	/* Nothing to do! */
2141 	con_flag_clear(con, CON_FLAG_WRITE_PENDING);
2142 	dout("try_write nothing else to write.\n");
2143 	ret = 0;
2144 out:
2145 	dout("try_write done on %p ret %d\n", con, ret);
2146 	return ret;
2147 }
2148 
2149 
2150 
2151 /*
2152  * Read what we can from the socket.
2153  */
2154 static int try_read(struct ceph_connection *con)
2155 {
2156 	int ret = -1;
2157 
2158 more:
2159 	dout("try_read start on %p state %lu\n", con, con->state);
2160 	if (con->state != CON_STATE_CONNECTING &&
2161 	    con->state != CON_STATE_NEGOTIATING &&
2162 	    con->state != CON_STATE_OPEN)
2163 		return 0;
2164 
2165 	BUG_ON(!con->sock);
2166 
2167 	dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,
2168 	     con->in_base_pos);
2169 
2170 	if (con->state == CON_STATE_CONNECTING) {
2171 		dout("try_read connecting\n");
2172 		ret = read_partial_banner(con);
2173 		if (ret <= 0)
2174 			goto out;
2175 		ret = process_banner(con);
2176 		if (ret < 0)
2177 			goto out;
2178 
2179 		con->state = CON_STATE_NEGOTIATING;
2180 
2181 		/*
2182 		 * Received banner is good, exchange connection info.
2183 		 * Do not reset out_kvec, as sending our banner raced
2184 		 * with receiving peer banner after connect completed.
2185 		 */
2186 		ret = prepare_write_connect(con);
2187 		if (ret < 0)
2188 			goto out;
2189 		prepare_read_connect(con);
2190 
2191 		/* Send connection info before awaiting response */
2192 		goto out;
2193 	}
2194 
2195 	if (con->state == CON_STATE_NEGOTIATING) {
2196 		dout("try_read negotiating\n");
2197 		ret = read_partial_connect(con);
2198 		if (ret <= 0)
2199 			goto out;
2200 		ret = process_connect(con);
2201 		if (ret < 0)
2202 			goto out;
2203 		goto more;
2204 	}
2205 
2206 	WARN_ON(con->state != CON_STATE_OPEN);
2207 
2208 	if (con->in_base_pos < 0) {
2209 		/*
2210 		 * skipping + discarding content.
2211 		 *
2212 		 * FIXME: there must be a better way to do this!
2213 		 */
2214 		static char buf[SKIP_BUF_SIZE];
2215 		int skip = min((int) sizeof (buf), -con->in_base_pos);
2216 
2217 		dout("skipping %d / %d bytes\n", skip, -con->in_base_pos);
2218 		ret = ceph_tcp_recvmsg(con->sock, buf, skip);
2219 		if (ret <= 0)
2220 			goto out;
2221 		con->in_base_pos += ret;
2222 		if (con->in_base_pos)
2223 			goto more;
2224 	}
2225 	if (con->in_tag == CEPH_MSGR_TAG_READY) {
2226 		/*
2227 		 * what's next?
2228 		 */
2229 		ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
2230 		if (ret <= 0)
2231 			goto out;
2232 		dout("try_read got tag %d\n", (int)con->in_tag);
2233 		switch (con->in_tag) {
2234 		case CEPH_MSGR_TAG_MSG:
2235 			prepare_read_message(con);
2236 			break;
2237 		case CEPH_MSGR_TAG_ACK:
2238 			prepare_read_ack(con);
2239 			break;
2240 		case CEPH_MSGR_TAG_CLOSE:
2241 			con_close_socket(con);
2242 			con->state = CON_STATE_CLOSED;
2243 			goto out;
2244 		default:
2245 			goto bad_tag;
2246 		}
2247 	}
2248 	if (con->in_tag == CEPH_MSGR_TAG_MSG) {
2249 		ret = read_partial_message(con);
2250 		if (ret <= 0) {
2251 			switch (ret) {
2252 			case -EBADMSG:
2253 				con->error_msg = "bad crc";
2254 				ret = -EIO;
2255 				break;
2256 			case -EIO:
2257 				con->error_msg = "io error";
2258 				break;
2259 			}
2260 			goto out;
2261 		}
2262 		if (con->in_tag == CEPH_MSGR_TAG_READY)
2263 			goto more;
2264 		process_message(con);
2265 		if (con->state == CON_STATE_OPEN)
2266 			prepare_read_tag(con);
2267 		goto more;
2268 	}
2269 	if (con->in_tag == CEPH_MSGR_TAG_ACK) {
2270 		ret = read_partial_ack(con);
2271 		if (ret <= 0)
2272 			goto out;
2273 		process_ack(con);
2274 		goto more;
2275 	}
2276 
2277 out:
2278 	dout("try_read done on %p ret %d\n", con, ret);
2279 	return ret;
2280 
2281 bad_tag:
2282 	pr_err("try_read bad con->in_tag = %d\n", (int)con->in_tag);
2283 	con->error_msg = "protocol error, garbage tag";
2284 	ret = -1;
2285 	goto out;
2286 }
2287 
2288 
2289 /*
2290  * Atomically queue work on a connection after the specified delay.
2291  * Bump @con reference to avoid races with connection teardown.
2292  * Returns 0 if work was queued, or an error code otherwise.
2293  */
2294 static int queue_con_delay(struct ceph_connection *con, unsigned long delay)
2295 {
2296 	if (!con->ops->get(con)) {
2297 		dout("%s %p ref count 0\n", __func__, con);
2298 
2299 		return -ENOENT;
2300 	}
2301 
2302 	if (!queue_delayed_work(ceph_msgr_wq, &con->work, delay)) {
2303 		dout("%s %p - already queued\n", __func__, con);
2304 		con->ops->put(con);
2305 
2306 		return -EBUSY;
2307 	}
2308 
2309 	dout("%s %p %lu\n", __func__, con, delay);
2310 
2311 	return 0;
2312 }
2313 
2314 static void queue_con(struct ceph_connection *con)
2315 {
2316 	(void) queue_con_delay(con, 0);
2317 }
2318 
2319 static bool con_sock_closed(struct ceph_connection *con)
2320 {
2321 	if (!con_flag_test_and_clear(con, CON_FLAG_SOCK_CLOSED))
2322 		return false;
2323 
2324 #define CASE(x)								\
2325 	case CON_STATE_ ## x:						\
2326 		con->error_msg = "socket closed (con state " #x ")";	\
2327 		break;
2328 
2329 	switch (con->state) {
2330 	CASE(CLOSED);
2331 	CASE(PREOPEN);
2332 	CASE(CONNECTING);
2333 	CASE(NEGOTIATING);
2334 	CASE(OPEN);
2335 	CASE(STANDBY);
2336 	default:
2337 		pr_warning("%s con %p unrecognized state %lu\n",
2338 			__func__, con, con->state);
2339 		con->error_msg = "unrecognized con state";
2340 		BUG();
2341 		break;
2342 	}
2343 #undef CASE
2344 
2345 	return true;
2346 }
2347 
2348 static bool con_backoff(struct ceph_connection *con)
2349 {
2350 	int ret;
2351 
2352 	if (!con_flag_test_and_clear(con, CON_FLAG_BACKOFF))
2353 		return false;
2354 
2355 	ret = queue_con_delay(con, round_jiffies_relative(con->delay));
2356 	if (ret) {
2357 		dout("%s: con %p FAILED to back off %lu\n", __func__,
2358 			con, con->delay);
2359 		BUG_ON(ret == -ENOENT);
2360 		con_flag_set(con, CON_FLAG_BACKOFF);
2361 	}
2362 
2363 	return true;
2364 }
2365 
2366 /* Finish fault handling; con->mutex must *not* be held here */
2367 
2368 static void con_fault_finish(struct ceph_connection *con)
2369 {
2370 	/*
2371 	 * in case we faulted due to authentication, invalidate our
2372 	 * current tickets so that we can get new ones.
2373 	 */
2374 	if (con->auth_retry && con->ops->invalidate_authorizer) {
2375 		dout("calling invalidate_authorizer()\n");
2376 		con->ops->invalidate_authorizer(con);
2377 	}
2378 
2379 	if (con->ops->fault)
2380 		con->ops->fault(con);
2381 }
2382 
2383 /*
2384  * Do some work on a connection.  Drop a connection ref when we're done.
2385  */
2386 static void con_work(struct work_struct *work)
2387 {
2388 	struct ceph_connection *con = container_of(work, struct ceph_connection,
2389 						   work.work);
2390 	bool fault;
2391 
2392 	mutex_lock(&con->mutex);
2393 	while (true) {
2394 		int ret;
2395 
2396 		if ((fault = con_sock_closed(con))) {
2397 			dout("%s: con %p SOCK_CLOSED\n", __func__, con);
2398 			break;
2399 		}
2400 		if (con_backoff(con)) {
2401 			dout("%s: con %p BACKOFF\n", __func__, con);
2402 			break;
2403 		}
2404 		if (con->state == CON_STATE_STANDBY) {
2405 			dout("%s: con %p STANDBY\n", __func__, con);
2406 			break;
2407 		}
2408 		if (con->state == CON_STATE_CLOSED) {
2409 			dout("%s: con %p CLOSED\n", __func__, con);
2410 			BUG_ON(con->sock);
2411 			break;
2412 		}
2413 		if (con->state == CON_STATE_PREOPEN) {
2414 			dout("%s: con %p PREOPEN\n", __func__, con);
2415 			BUG_ON(con->sock);
2416 		}
2417 
2418 		ret = try_read(con);
2419 		if (ret < 0) {
2420 			if (ret == -EAGAIN)
2421 				continue;
2422 			con->error_msg = "socket error on read";
2423 			fault = true;
2424 			break;
2425 		}
2426 
2427 		ret = try_write(con);
2428 		if (ret < 0) {
2429 			if (ret == -EAGAIN)
2430 				continue;
2431 			con->error_msg = "socket error on write";
2432 			fault = true;
2433 		}
2434 
2435 		break;	/* If we make it to here, we're done */
2436 	}
2437 	if (fault)
2438 		con_fault(con);
2439 	mutex_unlock(&con->mutex);
2440 
2441 	if (fault)
2442 		con_fault_finish(con);
2443 
2444 	con->ops->put(con);
2445 }
2446 
2447 /*
2448  * Generic error/fault handler.  A retry mechanism is used with
2449  * exponential backoff
2450  */
2451 static void con_fault(struct ceph_connection *con)
2452 {
2453 	pr_warning("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
2454 	       ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg);
2455 	dout("fault %p state %lu to peer %s\n",
2456 	     con, con->state, ceph_pr_addr(&con->peer_addr.in_addr));
2457 
2458 	WARN_ON(con->state != CON_STATE_CONNECTING &&
2459 	       con->state != CON_STATE_NEGOTIATING &&
2460 	       con->state != CON_STATE_OPEN);
2461 
2462 	con_close_socket(con);
2463 
2464 	if (con_flag_test(con, CON_FLAG_LOSSYTX)) {
2465 		dout("fault on LOSSYTX channel, marking CLOSED\n");
2466 		con->state = CON_STATE_CLOSED;
2467 		return;
2468 	}
2469 
2470 	if (con->in_msg) {
2471 		BUG_ON(con->in_msg->con != con);
2472 		con->in_msg->con = NULL;
2473 		ceph_msg_put(con->in_msg);
2474 		con->in_msg = NULL;
2475 		con->ops->put(con);
2476 	}
2477 
2478 	/* Requeue anything that hasn't been acked */
2479 	list_splice_init(&con->out_sent, &con->out_queue);
2480 
2481 	/* If there are no messages queued or keepalive pending, place
2482 	 * the connection in a STANDBY state */
2483 	if (list_empty(&con->out_queue) &&
2484 	    !con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING)) {
2485 		dout("fault %p setting STANDBY clearing WRITE_PENDING\n", con);
2486 		con_flag_clear(con, CON_FLAG_WRITE_PENDING);
2487 		con->state = CON_STATE_STANDBY;
2488 	} else {
2489 		/* retry after a delay. */
2490 		con->state = CON_STATE_PREOPEN;
2491 		if (con->delay == 0)
2492 			con->delay = BASE_DELAY_INTERVAL;
2493 		else if (con->delay < MAX_DELAY_INTERVAL)
2494 			con->delay *= 2;
2495 		con_flag_set(con, CON_FLAG_BACKOFF);
2496 		queue_con(con);
2497 	}
2498 }
2499 
2500 
2501 
2502 /*
2503  * initialize a new messenger instance
2504  */
2505 void ceph_messenger_init(struct ceph_messenger *msgr,
2506 			struct ceph_entity_addr *myaddr,
2507 			u32 supported_features,
2508 			u32 required_features,
2509 			bool nocrc)
2510 {
2511 	msgr->supported_features = supported_features;
2512 	msgr->required_features = required_features;
2513 
2514 	spin_lock_init(&msgr->global_seq_lock);
2515 
2516 	if (myaddr)
2517 		msgr->inst.addr = *myaddr;
2518 
2519 	/* select a random nonce */
2520 	msgr->inst.addr.type = 0;
2521 	get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
2522 	encode_my_addr(msgr);
2523 	msgr->nocrc = nocrc;
2524 
2525 	atomic_set(&msgr->stopping, 0);
2526 
2527 	dout("%s %p\n", __func__, msgr);
2528 }
2529 EXPORT_SYMBOL(ceph_messenger_init);
2530 
2531 static void clear_standby(struct ceph_connection *con)
2532 {
2533 	/* come back from STANDBY? */
2534 	if (con->state == CON_STATE_STANDBY) {
2535 		dout("clear_standby %p and ++connect_seq\n", con);
2536 		con->state = CON_STATE_PREOPEN;
2537 		con->connect_seq++;
2538 		WARN_ON(con_flag_test(con, CON_FLAG_WRITE_PENDING));
2539 		WARN_ON(con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING));
2540 	}
2541 }
2542 
2543 /*
2544  * Queue up an outgoing message on the given connection.
2545  */
2546 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
2547 {
2548 	/* set src+dst */
2549 	msg->hdr.src = con->msgr->inst.name;
2550 	BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
2551 	msg->needs_out_seq = true;
2552 
2553 	mutex_lock(&con->mutex);
2554 
2555 	if (con->state == CON_STATE_CLOSED) {
2556 		dout("con_send %p closed, dropping %p\n", con, msg);
2557 		ceph_msg_put(msg);
2558 		mutex_unlock(&con->mutex);
2559 		return;
2560 	}
2561 
2562 	BUG_ON(msg->con != NULL);
2563 	msg->con = con->ops->get(con);
2564 	BUG_ON(msg->con == NULL);
2565 
2566 	BUG_ON(!list_empty(&msg->list_head));
2567 	list_add_tail(&msg->list_head, &con->out_queue);
2568 	dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
2569 	     ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
2570 	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
2571 	     le32_to_cpu(msg->hdr.front_len),
2572 	     le32_to_cpu(msg->hdr.middle_len),
2573 	     le32_to_cpu(msg->hdr.data_len));
2574 
2575 	clear_standby(con);
2576 	mutex_unlock(&con->mutex);
2577 
2578 	/* if there wasn't anything waiting to send before, queue
2579 	 * new work */
2580 	if (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
2581 		queue_con(con);
2582 }
2583 EXPORT_SYMBOL(ceph_con_send);
2584 
2585 /*
2586  * Revoke a message that was previously queued for send
2587  */
2588 void ceph_msg_revoke(struct ceph_msg *msg)
2589 {
2590 	struct ceph_connection *con = msg->con;
2591 
2592 	if (!con)
2593 		return;		/* Message not in our possession */
2594 
2595 	mutex_lock(&con->mutex);
2596 	if (!list_empty(&msg->list_head)) {
2597 		dout("%s %p msg %p - was on queue\n", __func__, con, msg);
2598 		list_del_init(&msg->list_head);
2599 		BUG_ON(msg->con == NULL);
2600 		msg->con->ops->put(msg->con);
2601 		msg->con = NULL;
2602 		msg->hdr.seq = 0;
2603 
2604 		ceph_msg_put(msg);
2605 	}
2606 	if (con->out_msg == msg) {
2607 		dout("%s %p msg %p - was sending\n", __func__, con, msg);
2608 		con->out_msg = NULL;
2609 		if (con->out_kvec_is_msg) {
2610 			con->out_skip = con->out_kvec_bytes;
2611 			con->out_kvec_is_msg = false;
2612 		}
2613 		msg->hdr.seq = 0;
2614 
2615 		ceph_msg_put(msg);
2616 	}
2617 	mutex_unlock(&con->mutex);
2618 }
2619 
2620 /*
2621  * Revoke a message that we may be reading data into
2622  */
2623 void ceph_msg_revoke_incoming(struct ceph_msg *msg)
2624 {
2625 	struct ceph_connection *con;
2626 
2627 	BUG_ON(msg == NULL);
2628 	if (!msg->con) {
2629 		dout("%s msg %p null con\n", __func__, msg);
2630 
2631 		return;		/* Message not in our possession */
2632 	}
2633 
2634 	con = msg->con;
2635 	mutex_lock(&con->mutex);
2636 	if (con->in_msg == msg) {
2637 		unsigned int front_len = le32_to_cpu(con->in_hdr.front_len);
2638 		unsigned int middle_len = le32_to_cpu(con->in_hdr.middle_len);
2639 		unsigned int data_len = le32_to_cpu(con->in_hdr.data_len);
2640 
2641 		/* skip rest of message */
2642 		dout("%s %p msg %p revoked\n", __func__, con, msg);
2643 		con->in_base_pos = con->in_base_pos -
2644 				sizeof(struct ceph_msg_header) -
2645 				front_len -
2646 				middle_len -
2647 				data_len -
2648 				sizeof(struct ceph_msg_footer);
2649 		ceph_msg_put(con->in_msg);
2650 		con->in_msg = NULL;
2651 		con->in_tag = CEPH_MSGR_TAG_READY;
2652 		con->in_seq++;
2653 	} else {
2654 		dout("%s %p in_msg %p msg %p no-op\n",
2655 		     __func__, con, con->in_msg, msg);
2656 	}
2657 	mutex_unlock(&con->mutex);
2658 }
2659 
2660 /*
2661  * Queue a keepalive byte to ensure the tcp connection is alive.
2662  */
2663 void ceph_con_keepalive(struct ceph_connection *con)
2664 {
2665 	dout("con_keepalive %p\n", con);
2666 	mutex_lock(&con->mutex);
2667 	clear_standby(con);
2668 	mutex_unlock(&con->mutex);
2669 	if (con_flag_test_and_set(con, CON_FLAG_KEEPALIVE_PENDING) == 0 &&
2670 	    con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
2671 		queue_con(con);
2672 }
2673 EXPORT_SYMBOL(ceph_con_keepalive);
2674 
2675 
2676 /*
2677  * construct a new message with given type, size
2678  * the new msg has a ref count of 1.
2679  */
2680 struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
2681 			      bool can_fail)
2682 {
2683 	struct ceph_msg *m;
2684 
2685 	m = kmalloc(sizeof(*m), flags);
2686 	if (m == NULL)
2687 		goto out;
2688 	kref_init(&m->kref);
2689 
2690 	m->con = NULL;
2691 	INIT_LIST_HEAD(&m->list_head);
2692 
2693 	m->hdr.tid = 0;
2694 	m->hdr.type = cpu_to_le16(type);
2695 	m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
2696 	m->hdr.version = 0;
2697 	m->hdr.front_len = cpu_to_le32(front_len);
2698 	m->hdr.middle_len = 0;
2699 	m->hdr.data_len = 0;
2700 	m->hdr.data_off = 0;
2701 	m->hdr.reserved = 0;
2702 	m->footer.front_crc = 0;
2703 	m->footer.middle_crc = 0;
2704 	m->footer.data_crc = 0;
2705 	m->footer.flags = 0;
2706 	m->front_max = front_len;
2707 	m->front_is_vmalloc = false;
2708 	m->more_to_follow = false;
2709 	m->ack_stamp = 0;
2710 	m->pool = NULL;
2711 
2712 	/* middle */
2713 	m->middle = NULL;
2714 
2715 	/* data */
2716 	m->nr_pages = 0;
2717 	m->page_alignment = 0;
2718 	m->pages = NULL;
2719 	m->pagelist = NULL;
2720 #ifdef	CONFIG_BLOCK
2721 	m->bio = NULL;
2722 	m->bio_iter = NULL;
2723 	m->bio_seg = 0;
2724 #endif	/* CONFIG_BLOCK */
2725 	m->trail = NULL;
2726 
2727 	/* front */
2728 	if (front_len) {
2729 		if (front_len > PAGE_CACHE_SIZE) {
2730 			m->front.iov_base = __vmalloc(front_len, flags,
2731 						      PAGE_KERNEL);
2732 			m->front_is_vmalloc = true;
2733 		} else {
2734 			m->front.iov_base = kmalloc(front_len, flags);
2735 		}
2736 		if (m->front.iov_base == NULL) {
2737 			dout("ceph_msg_new can't allocate %d bytes\n",
2738 			     front_len);
2739 			goto out2;
2740 		}
2741 	} else {
2742 		m->front.iov_base = NULL;
2743 	}
2744 	m->front.iov_len = front_len;
2745 
2746 	dout("ceph_msg_new %p front %d\n", m, front_len);
2747 	return m;
2748 
2749 out2:
2750 	ceph_msg_put(m);
2751 out:
2752 	if (!can_fail) {
2753 		pr_err("msg_new can't create type %d front %d\n", type,
2754 		       front_len);
2755 		WARN_ON(1);
2756 	} else {
2757 		dout("msg_new can't create type %d front %d\n", type,
2758 		     front_len);
2759 	}
2760 	return NULL;
2761 }
2762 EXPORT_SYMBOL(ceph_msg_new);
2763 
2764 /*
2765  * Allocate "middle" portion of a message, if it is needed and wasn't
2766  * allocated by alloc_msg.  This allows us to read a small fixed-size
2767  * per-type header in the front and then gracefully fail (i.e.,
2768  * propagate the error to the caller based on info in the front) when
2769  * the middle is too large.
2770  */
2771 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
2772 {
2773 	int type = le16_to_cpu(msg->hdr.type);
2774 	int middle_len = le32_to_cpu(msg->hdr.middle_len);
2775 
2776 	dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
2777 	     ceph_msg_type_name(type), middle_len);
2778 	BUG_ON(!middle_len);
2779 	BUG_ON(msg->middle);
2780 
2781 	msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
2782 	if (!msg->middle)
2783 		return -ENOMEM;
2784 	return 0;
2785 }
2786 
2787 /*
2788  * Allocate a message for receiving an incoming message on a
2789  * connection, and save the result in con->in_msg.  Uses the
2790  * connection's private alloc_msg op if available.
2791  *
2792  * Returns 0 on success, or a negative error code.
2793  *
2794  * On success, if we set *skip = 1:
2795  *  - the next message should be skipped and ignored.
2796  *  - con->in_msg == NULL
2797  * or if we set *skip = 0:
2798  *  - con->in_msg is non-null.
2799  * On error (ENOMEM, EAGAIN, ...),
2800  *  - con->in_msg == NULL
2801  */
2802 static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
2803 {
2804 	struct ceph_msg_header *hdr = &con->in_hdr;
2805 	int type = le16_to_cpu(hdr->type);
2806 	int front_len = le32_to_cpu(hdr->front_len);
2807 	int middle_len = le32_to_cpu(hdr->middle_len);
2808 	int ret = 0;
2809 
2810 	BUG_ON(con->in_msg != NULL);
2811 
2812 	if (con->ops->alloc_msg) {
2813 		struct ceph_msg *msg;
2814 
2815 		mutex_unlock(&con->mutex);
2816 		msg = con->ops->alloc_msg(con, hdr, skip);
2817 		mutex_lock(&con->mutex);
2818 		if (con->state != CON_STATE_OPEN) {
2819 			if (msg)
2820 				ceph_msg_put(msg);
2821 			return -EAGAIN;
2822 		}
2823 		con->in_msg = msg;
2824 		if (con->in_msg) {
2825 			con->in_msg->con = con->ops->get(con);
2826 			BUG_ON(con->in_msg->con == NULL);
2827 		}
2828 		if (*skip) {
2829 			con->in_msg = NULL;
2830 			return 0;
2831 		}
2832 		if (!con->in_msg) {
2833 			con->error_msg =
2834 				"error allocating memory for incoming message";
2835 			return -ENOMEM;
2836 		}
2837 	}
2838 	if (!con->in_msg) {
2839 		con->in_msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
2840 		if (!con->in_msg) {
2841 			pr_err("unable to allocate msg type %d len %d\n",
2842 			       type, front_len);
2843 			return -ENOMEM;
2844 		}
2845 		con->in_msg->con = con->ops->get(con);
2846 		BUG_ON(con->in_msg->con == NULL);
2847 		con->in_msg->page_alignment = le16_to_cpu(hdr->data_off);
2848 	}
2849 	memcpy(&con->in_msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
2850 
2851 	if (middle_len && !con->in_msg->middle) {
2852 		ret = ceph_alloc_middle(con, con->in_msg);
2853 		if (ret < 0) {
2854 			ceph_msg_put(con->in_msg);
2855 			con->in_msg = NULL;
2856 		}
2857 	}
2858 
2859 	return ret;
2860 }
2861 
2862 
2863 /*
2864  * Free a generically kmalloc'd message.
2865  */
2866 void ceph_msg_kfree(struct ceph_msg *m)
2867 {
2868 	dout("msg_kfree %p\n", m);
2869 	if (m->front_is_vmalloc)
2870 		vfree(m->front.iov_base);
2871 	else
2872 		kfree(m->front.iov_base);
2873 	kfree(m);
2874 }
2875 
2876 /*
2877  * Drop a msg ref.  Destroy as needed.
2878  */
2879 void ceph_msg_last_put(struct kref *kref)
2880 {
2881 	struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
2882 
2883 	dout("ceph_msg_put last one on %p\n", m);
2884 	WARN_ON(!list_empty(&m->list_head));
2885 
2886 	/* drop middle, data, if any */
2887 	if (m->middle) {
2888 		ceph_buffer_put(m->middle);
2889 		m->middle = NULL;
2890 	}
2891 	m->nr_pages = 0;
2892 	m->pages = NULL;
2893 
2894 	if (m->pagelist) {
2895 		ceph_pagelist_release(m->pagelist);
2896 		kfree(m->pagelist);
2897 		m->pagelist = NULL;
2898 	}
2899 
2900 	m->trail = NULL;
2901 
2902 	if (m->pool)
2903 		ceph_msgpool_put(m->pool, m);
2904 	else
2905 		ceph_msg_kfree(m);
2906 }
2907 EXPORT_SYMBOL(ceph_msg_last_put);
2908 
2909 void ceph_msg_dump(struct ceph_msg *msg)
2910 {
2911 	pr_debug("msg_dump %p (front_max %d nr_pages %d)\n", msg,
2912 		 msg->front_max, msg->nr_pages);
2913 	print_hex_dump(KERN_DEBUG, "header: ",
2914 		       DUMP_PREFIX_OFFSET, 16, 1,
2915 		       &msg->hdr, sizeof(msg->hdr), true);
2916 	print_hex_dump(KERN_DEBUG, " front: ",
2917 		       DUMP_PREFIX_OFFSET, 16, 1,
2918 		       msg->front.iov_base, msg->front.iov_len, true);
2919 	if (msg->middle)
2920 		print_hex_dump(KERN_DEBUG, "middle: ",
2921 			       DUMP_PREFIX_OFFSET, 16, 1,
2922 			       msg->middle->vec.iov_base,
2923 			       msg->middle->vec.iov_len, true);
2924 	print_hex_dump(KERN_DEBUG, "footer: ",
2925 		       DUMP_PREFIX_OFFSET, 16, 1,
2926 		       &msg->footer, sizeof(msg->footer), true);
2927 }
2928 EXPORT_SYMBOL(ceph_msg_dump);
2929