1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/ceph/ceph_debug.h>
   3
   4#include <linux/crc32c.h>
   5#include <linux/ctype.h>
   6#include <linux/highmem.h>
   7#include <linux/inet.h>
   8#include <linux/kthread.h>
   9#include <linux/net.h>
  10#include <linux/nsproxy.h>
  11#include <linux/sched/mm.h>
  12#include <linux/slab.h>
  13#include <linux/socket.h>
  14#include <linux/string.h>
  15#ifdef	CONFIG_BLOCK
  16#include <linux/bio.h>
  17#endif	/* CONFIG_BLOCK */
  18#include <linux/dns_resolver.h>
  19#include <net/tcp.h>
  20#include <trace/events/sock.h>
  21
  22#include <linux/ceph/ceph_features.h>
  23#include <linux/ceph/libceph.h>
  24#include <linux/ceph/messenger.h>
  25#include <linux/ceph/decode.h>
  26#include <linux/ceph/pagelist.h>
  27#include <linux/export.h>
  28
  29/*
  30 * Ceph uses the messenger to exchange ceph_msg messages with other
  31 * hosts in the system.  The messenger provides ordered and reliable
  32 * delivery.  We tolerate TCP disconnects by reconnecting (with
  33 * exponential backoff) in the case of a fault (disconnection, bad
  34 * crc, protocol error).  Acks allow sent messages to be discarded by
  35 * the sender.
  36 */
  37
  38/*
  39 * We track the state of the socket on a given connection using
  40 * values defined below.  The transition to a new socket state is
  41 * handled by a function which verifies we aren't coming from an
  42 * unexpected state.
  43 *
  44 *      --------
  45 *      | NEW* |  transient initial state
  46 *      --------
  47 *          | con_sock_state_init()
  48 *          v
  49 *      ----------
  50 *      | CLOSED |  initialized, but no socket (and no
  51 *      ----------  TCP connection)
  52 *       ^      \
  53 *       |       \ con_sock_state_connecting()
  54 *       |        ----------------------
  55 *       |                              \
  56 *       + con_sock_state_closed()       \
  57 *       |+---------------------------    \
  58 *       | \                          \    \
  59 *       |  -----------                \    \
  60 *       |  | CLOSING |  socket event;  \    \
  61 *       |  -----------  await close     \    \
  62 *       |       ^                        \   |
  63 *       |       |                         \  |
  64 *       |       + con_sock_state_closing() \ |
  65 *       |      / \                         | |
  66 *       |     /   ---------------          | |
  67 *       |    /                   \         v v
  68 *       |   /                    --------------
  69 *       |  /    -----------------| CONNECTING |  socket created, TCP
  70 *       |  |   /                 --------------  connect initiated
  71 *       |  |   | con_sock_state_connected()
  72 *       |  |   v
  73 *      -------------
  74 *      | CONNECTED |  TCP connection established
  75 *      -------------
  76 *
  77 * State values for ceph_connection->sock_state; NEW is assumed to be 0.
  78 */
  79
  80#define CON_SOCK_STATE_NEW		0	/* -> CLOSED */
  81#define CON_SOCK_STATE_CLOSED		1	/* -> CONNECTING */
  82#define CON_SOCK_STATE_CONNECTING	2	/* -> CONNECTED or -> CLOSING */
  83#define CON_SOCK_STATE_CONNECTED	3	/* -> CLOSING or -> CLOSED */
  84#define CON_SOCK_STATE_CLOSING		4	/* -> CLOSED */
  85
  86static bool con_flag_valid(unsigned long con_flag)
  87{
  88	switch (con_flag) {
  89	case CEPH_CON_F_LOSSYTX:
  90	case CEPH_CON_F_KEEPALIVE_PENDING:
  91	case CEPH_CON_F_WRITE_PENDING:
  92	case CEPH_CON_F_SOCK_CLOSED:
  93	case CEPH_CON_F_BACKOFF:
  94		return true;
  95	default:
  96		return false;
  97	}
  98}
  99
 100void ceph_con_flag_clear(struct ceph_connection *con, unsigned long con_flag)
 101{
 102	BUG_ON(!con_flag_valid(con_flag));
 103
 104	clear_bit(con_flag, &con->flags);
 105}
 106
 107void ceph_con_flag_set(struct ceph_connection *con, unsigned long con_flag)
 108{
 109	BUG_ON(!con_flag_valid(con_flag));
 110
 111	set_bit(con_flag, &con->flags);
 112}
 113
 114bool ceph_con_flag_test(struct ceph_connection *con, unsigned long con_flag)
 115{
 116	BUG_ON(!con_flag_valid(con_flag));
 117
 118	return test_bit(con_flag, &con->flags);
 119}
 120
 121bool ceph_con_flag_test_and_clear(struct ceph_connection *con,
 122				  unsigned long con_flag)
 123{
 124	BUG_ON(!con_flag_valid(con_flag));
 125
 126	return test_and_clear_bit(con_flag, &con->flags);
 127}
 128
 129bool ceph_con_flag_test_and_set(struct ceph_connection *con,
 130				unsigned long con_flag)
 131{
 132	BUG_ON(!con_flag_valid(con_flag));
 133
 134	return test_and_set_bit(con_flag, &con->flags);
 135}
 136
 137/* Slab caches for frequently-allocated structures */
 138
 139static struct kmem_cache	*ceph_msg_cache;
 140
 141#ifdef CONFIG_LOCKDEP
 142static struct lock_class_key socket_class;
 143#endif
 144
 145static void queue_con(struct ceph_connection *con);
 146static void cancel_con(struct ceph_connection *con);
 147static void ceph_con_workfn(struct work_struct *);
 148static void con_fault(struct ceph_connection *con);
 149
 150/*
 151 * Nicely render a sockaddr as a string.  An array of formatted
 152 * strings is used, to approximate reentrancy.
 153 */
 154#define ADDR_STR_COUNT_LOG	5	/* log2(# address strings in array) */
 155#define ADDR_STR_COUNT		(1 << ADDR_STR_COUNT_LOG)
 156#define ADDR_STR_COUNT_MASK	(ADDR_STR_COUNT - 1)
 157#define MAX_ADDR_STR_LEN	64	/* 54 is enough */
 158
 159static char addr_str[ADDR_STR_COUNT][MAX_ADDR_STR_LEN];
 160static atomic_t addr_str_seq = ATOMIC_INIT(0);
 161
 162struct page *ceph_zero_page;		/* used in certain error cases */
 163
 164const char *ceph_pr_addr(const struct ceph_entity_addr *addr)
 165{
 166	int i;
 167	char *s;
 168	struct sockaddr_storage ss = addr->in_addr; /* align */
 169	struct sockaddr_in *in4 = (struct sockaddr_in *)&ss;
 170	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&ss;
 171
 172	i = atomic_inc_return(&addr_str_seq) & ADDR_STR_COUNT_MASK;
 173	s = addr_str[i];
 174
 175	switch (ss.ss_family) {
 176	case AF_INET:
 177		snprintf(s, MAX_ADDR_STR_LEN, "(%d)%pI4:%hu",
 178			 le32_to_cpu(addr->type), &in4->sin_addr,
 179			 ntohs(in4->sin_port));
 180		break;
 181
 182	case AF_INET6:
 183		snprintf(s, MAX_ADDR_STR_LEN, "(%d)[%pI6c]:%hu",
 184			 le32_to_cpu(addr->type), &in6->sin6_addr,
 185			 ntohs(in6->sin6_port));
 186		break;
 187
 188	default:
 189		snprintf(s, MAX_ADDR_STR_LEN, "(unknown sockaddr family %hu)",
 190			 ss.ss_family);
 191	}
 192
 193	return s;
 194}
 195EXPORT_SYMBOL(ceph_pr_addr);
 196
 197void ceph_encode_my_addr(struct ceph_messenger *msgr)
 198{
 199	if (!ceph_msgr2(from_msgr(msgr))) {
 200		memcpy(&msgr->my_enc_addr, &msgr->inst.addr,
 201		       sizeof(msgr->my_enc_addr));
 202		ceph_encode_banner_addr(&msgr->my_enc_addr);
 203	}
 204}
 205
 206/*
 207 * work queue for all reading and writing to/from the socket.
 208 */
 209static struct workqueue_struct *ceph_msgr_wq;
 210
 211static int ceph_msgr_slab_init(void)
 212{
 213	BUG_ON(ceph_msg_cache);
 214	ceph_msg_cache = KMEM_CACHE(ceph_msg, 0);
 215	if (!ceph_msg_cache)
 216		return -ENOMEM;
 217
 218	return 0;
 219}
 220
 221static void ceph_msgr_slab_exit(void)
 222{
 223	BUG_ON(!ceph_msg_cache);
 224	kmem_cache_destroy(ceph_msg_cache);
 225	ceph_msg_cache = NULL;
 226}
 227
 228static void _ceph_msgr_exit(void)
 229{
 230	if (ceph_msgr_wq) {
 231		destroy_workqueue(ceph_msgr_wq);
 232		ceph_msgr_wq = NULL;
 233	}
 234
 235	BUG_ON(!ceph_zero_page);
 236	put_page(ceph_zero_page);
 237	ceph_zero_page = NULL;
 238
 239	ceph_msgr_slab_exit();
 240}
 241
 242int __init ceph_msgr_init(void)
 243{
 244	if (ceph_msgr_slab_init())
 245		return -ENOMEM;
 246
 247	BUG_ON(ceph_zero_page);
 248	ceph_zero_page = ZERO_PAGE(0);
 249	get_page(ceph_zero_page);
 250
 251	/*
 252	 * The number of active work items is limited by the number of
 253	 * connections, so leave @max_active at default.
 254	 */
 255	ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_MEM_RECLAIM, 0);
 256	if (ceph_msgr_wq)
 257		return 0;
 258
 259	pr_err("msgr_init failed to create workqueue\n");
 260	_ceph_msgr_exit();
 261
 262	return -ENOMEM;
 263}
 264
 265void ceph_msgr_exit(void)
 266{
 267	BUG_ON(ceph_msgr_wq == NULL);
 268
 269	_ceph_msgr_exit();
 270}
 271
 272void ceph_msgr_flush(void)
 273{
 274	flush_workqueue(ceph_msgr_wq);
 275}
 276EXPORT_SYMBOL(ceph_msgr_flush);
 277
 278/* Connection socket state transition functions */
 279
 280static void con_sock_state_init(struct ceph_connection *con)
 281{
 282	int old_state;
 283
 284	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
 285	if (WARN_ON(old_state != CON_SOCK_STATE_NEW))
 286		printk("%s: unexpected old state %d\n", __func__, old_state);
 287	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 288	     CON_SOCK_STATE_CLOSED);
 289}
 290
 291static void con_sock_state_connecting(struct ceph_connection *con)
 292{
 293	int old_state;
 294
 295	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTING);
 296	if (WARN_ON(old_state != CON_SOCK_STATE_CLOSED))
 297		printk("%s: unexpected old state %d\n", __func__, old_state);
 298	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 299	     CON_SOCK_STATE_CONNECTING);
 300}
 301
 302static void con_sock_state_connected(struct ceph_connection *con)
 303{
 304	int old_state;
 305
 306	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTED);
 307	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING))
 308		printk("%s: unexpected old state %d\n", __func__, old_state);
 309	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 310	     CON_SOCK_STATE_CONNECTED);
 311}
 312
 313static void con_sock_state_closing(struct ceph_connection *con)
 314{
 315	int old_state;
 316
 317	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSING);
 318	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING &&
 319			old_state != CON_SOCK_STATE_CONNECTED &&
 320			old_state != CON_SOCK_STATE_CLOSING))
 321		printk("%s: unexpected old state %d\n", __func__, old_state);
 322	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 323	     CON_SOCK_STATE_CLOSING);
 324}
 325
 326static void con_sock_state_closed(struct ceph_connection *con)
 327{
 328	int old_state;
 329
 330	old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
 331	if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTED &&
 332		    old_state != CON_SOCK_STATE_CLOSING &&
 333		    old_state != CON_SOCK_STATE_CONNECTING &&
 334		    old_state != CON_SOCK_STATE_CLOSED))
 335		printk("%s: unexpected old state %d\n", __func__, old_state);
 336	dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
 337	     CON_SOCK_STATE_CLOSED);
 338}
 339
 340/*
 341 * socket callback functions
 342 */
 343
 344/* data available on socket, or listen socket received a connect */
 345static void ceph_sock_data_ready(struct sock *sk)
 346{
 347	struct ceph_connection *con = sk->sk_user_data;
 348
 349	trace_sk_data_ready(sk);
 350
 351	if (atomic_read(&con->msgr->stopping)) {
 352		return;
 353	}
 354
 355	if (sk->sk_state != TCP_CLOSE_WAIT) {
 356		dout("%s %p state = %d, queueing work\n", __func__,
 357		     con, con->state);
 358		queue_con(con);
 359	}
 360}
 361
 362/* socket has buffer space for writing */
 363static void ceph_sock_write_space(struct sock *sk)
 364{
 365	struct ceph_connection *con = sk->sk_user_data;
 366
 367	/* only queue to workqueue if there is data we want to write,
 368	 * and there is sufficient space in the socket buffer to accept
 369	 * more data.  clear SOCK_NOSPACE so that ceph_sock_write_space()
 370	 * doesn't get called again until try_write() fills the socket
 371	 * buffer. See net/ipv4/tcp_input.c:tcp_check_space()
 372	 * and net/core/stream.c:sk_stream_write_space().
 373	 */
 374	if (ceph_con_flag_test(con, CEPH_CON_F_WRITE_PENDING)) {
 375		if (sk_stream_is_writeable(sk)) {
 376			dout("%s %p queueing write work\n", __func__, con);
 377			clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 378			queue_con(con);
 379		}
 380	} else {
 381		dout("%s %p nothing to write\n", __func__, con);
 382	}
 383}
 384
 385/* socket's state has changed */
 386static void ceph_sock_state_change(struct sock *sk)
 387{
 388	struct ceph_connection *con = sk->sk_user_data;
 389
 390	dout("%s %p state = %d sk_state = %u\n", __func__,
 391	     con, con->state, sk->sk_state);
 392
 393	switch (sk->sk_state) {
 394	case TCP_CLOSE:
 395		dout("%s TCP_CLOSE\n", __func__);
 396		fallthrough;
 397	case TCP_CLOSE_WAIT:
 398		dout("%s TCP_CLOSE_WAIT\n", __func__);
 399		con_sock_state_closing(con);
 400		ceph_con_flag_set(con, CEPH_CON_F_SOCK_CLOSED);
 401		queue_con(con);
 402		break;
 403	case TCP_ESTABLISHED:
 404		dout("%s TCP_ESTABLISHED\n", __func__);
 405		con_sock_state_connected(con);
 406		queue_con(con);
 407		break;
 408	default:	/* Everything else is uninteresting */
 409		break;
 410	}
 411}
 412
 413/*
 414 * set up socket callbacks
 415 */
 416static void set_sock_callbacks(struct socket *sock,
 417			       struct ceph_connection *con)
 418{
 419	struct sock *sk = sock->sk;
 420	sk->sk_user_data = con;
 421	sk->sk_data_ready = ceph_sock_data_ready;
 422	sk->sk_write_space = ceph_sock_write_space;
 423	sk->sk_state_change = ceph_sock_state_change;
 424}
 425
 426
 427/*
 428 * socket helpers
 429 */
 430
 431/*
 432 * initiate connection to a remote socket.
 433 */
 434int ceph_tcp_connect(struct ceph_connection *con)
 435{
 436	struct sockaddr_storage ss = con->peer_addr.in_addr; /* align */
 437	struct socket *sock;
 438	unsigned int noio_flag;
 439	int ret;
 440
 441	dout("%s con %p peer_addr %s\n", __func__, con,
 442	     ceph_pr_addr(&con->peer_addr));
 443	BUG_ON(con->sock);
 444
 445	/* sock_create_kern() allocates with GFP_KERNEL */
 446	noio_flag = memalloc_noio_save();
 447	ret = sock_create_kern(read_pnet(&con->msgr->net), ss.ss_family,
 448			       SOCK_STREAM, IPPROTO_TCP, &sock);
 449	memalloc_noio_restore(noio_flag);
 450	if (ret)
 451		return ret;
 452	sock->sk->sk_allocation = GFP_NOFS;
 453	sock->sk->sk_use_task_frag = false;
 454
 455#ifdef CONFIG_LOCKDEP
 456	lockdep_set_class(&sock->sk->sk_lock, &socket_class);
 457#endif
 458
 459	set_sock_callbacks(sock, con);
 460
 461	con_sock_state_connecting(con);
 462	ret = kernel_connect(sock, (struct sockaddr *)&ss, sizeof(ss),
 463			     O_NONBLOCK);
 464	if (ret == -EINPROGRESS) {
 465		dout("connect %s EINPROGRESS sk_state = %u\n",
 466		     ceph_pr_addr(&con->peer_addr),
 467		     sock->sk->sk_state);
 468	} else if (ret < 0) {
 469		pr_err("connect %s error %d\n",
 470		       ceph_pr_addr(&con->peer_addr), ret);
 471		sock_release(sock);
 472		return ret;
 473	}
 474
 475	if (ceph_test_opt(from_msgr(con->msgr), TCP_NODELAY))
 476		tcp_sock_set_nodelay(sock->sk);
 477
 478	con->sock = sock;
 479	return 0;
 480}
 481
 482/*
 483 * Shutdown/close the socket for the given connection.
 484 */
 485int ceph_con_close_socket(struct ceph_connection *con)
 486{
 487	int rc = 0;
 488
 489	dout("%s con %p sock %p\n", __func__, con, con->sock);
 490	if (con->sock) {
 491		rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
 492		sock_release(con->sock);
 493		con->sock = NULL;
 494	}
 495
 496	/*
 497	 * Forcibly clear the SOCK_CLOSED flag.  It gets set
 498	 * independent of the connection mutex, and we could have
 499	 * received a socket close event before we had the chance to
 500	 * shut the socket down.
 501	 */
 502	ceph_con_flag_clear(con, CEPH_CON_F_SOCK_CLOSED);
 503
 504	con_sock_state_closed(con);
 505	return rc;
 506}
 507
 508static void ceph_con_reset_protocol(struct ceph_connection *con)
 509{
 510	dout("%s con %p\n", __func__, con);
 511
 512	ceph_con_close_socket(con);
 513	if (con->in_msg) {
 514		WARN_ON(con->in_msg->con != con);
 515		ceph_msg_put(con->in_msg);
 516		con->in_msg = NULL;
 517	}
 518	if (con->out_msg) {
 519		WARN_ON(con->out_msg->con != con);
 520		ceph_msg_put(con->out_msg);
 521		con->out_msg = NULL;
 522	}
 523	if (con->bounce_page) {
 524		__free_page(con->bounce_page);
 525		con->bounce_page = NULL;
 526	}
 527
 528	if (ceph_msgr2(from_msgr(con->msgr)))
 529		ceph_con_v2_reset_protocol(con);
 530	else
 531		ceph_con_v1_reset_protocol(con);
 532}
 533
 534/*
 535 * Reset a connection.  Discard all incoming and outgoing messages
 536 * and clear *_seq state.
 537 */
 538static void ceph_msg_remove(struct ceph_msg *msg)
 539{
 540	list_del_init(&msg->list_head);
 541
 542	ceph_msg_put(msg);
 543}
 544
 545static void ceph_msg_remove_list(struct list_head *head)
 546{
 547	while (!list_empty(head)) {
 548		struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
 549							list_head);
 550		ceph_msg_remove(msg);
 551	}
 552}
 553
 554void ceph_con_reset_session(struct ceph_connection *con)
 555{
 556	dout("%s con %p\n", __func__, con);
 557
 558	WARN_ON(con->in_msg);
 559	WARN_ON(con->out_msg);
 560	ceph_msg_remove_list(&con->out_queue);
 561	ceph_msg_remove_list(&con->out_sent);
 562	con->out_seq = 0;
 563	con->in_seq = 0;
 564	con->in_seq_acked = 0;
 565
 566	if (ceph_msgr2(from_msgr(con->msgr)))
 567		ceph_con_v2_reset_session(con);
 568	else
 569		ceph_con_v1_reset_session(con);
 570}
 571
 572/*
 573 * mark a peer down.  drop any open connections.
 574 */
 575void ceph_con_close(struct ceph_connection *con)
 576{
 577	mutex_lock(&con->mutex);
 578	dout("con_close %p peer %s\n", con, ceph_pr_addr(&con->peer_addr));
 579	con->state = CEPH_CON_S_CLOSED;
 580
 581	ceph_con_flag_clear(con, CEPH_CON_F_LOSSYTX);  /* so we retry next
 582							  connect */
 583	ceph_con_flag_clear(con, CEPH_CON_F_KEEPALIVE_PENDING);
 584	ceph_con_flag_clear(con, CEPH_CON_F_WRITE_PENDING);
 585	ceph_con_flag_clear(con, CEPH_CON_F_BACKOFF);
 586
 587	ceph_con_reset_protocol(con);
 588	ceph_con_reset_session(con);
 589	cancel_con(con);
 590	mutex_unlock(&con->mutex);
 591}
 592EXPORT_SYMBOL(ceph_con_close);
 593
 594/*
 595 * Reopen a closed connection, with a new peer address.
 596 */
 597void ceph_con_open(struct ceph_connection *con,
 598		   __u8 entity_type, __u64 entity_num,
 599		   struct ceph_entity_addr *addr)
 600{
 601	mutex_lock(&con->mutex);
 602	dout("con_open %p %s\n", con, ceph_pr_addr(addr));
 603
 604	WARN_ON(con->state != CEPH_CON_S_CLOSED);
 605	con->state = CEPH_CON_S_PREOPEN;
 606
 607	con->peer_name.type = (__u8) entity_type;
 608	con->peer_name.num = cpu_to_le64(entity_num);
 609
 610	memcpy(&con->peer_addr, addr, sizeof(*addr));
 611	con->delay = 0;      /* reset backoff memory */
 612	mutex_unlock(&con->mutex);
 613	queue_con(con);
 614}
 615EXPORT_SYMBOL(ceph_con_open);
 616
 617/*
 618 * return true if this connection ever successfully opened
 619 */
 620bool ceph_con_opened(struct ceph_connection *con)
 621{
 622	if (ceph_msgr2(from_msgr(con->msgr)))
 623		return ceph_con_v2_opened(con);
 624
 625	return ceph_con_v1_opened(con);
 626}
 627
 628/*
 629 * initialize a new connection.
 630 */
 631void ceph_con_init(struct ceph_connection *con, void *private,
 632	const struct ceph_connection_operations *ops,
 633	struct ceph_messenger *msgr)
 634{
 635	dout("con_init %p\n", con);
 636	memset(con, 0, sizeof(*con));
 637	con->private = private;
 638	con->ops = ops;
 639	con->msgr = msgr;
 640
 641	con_sock_state_init(con);
 642
 643	mutex_init(&con->mutex);
 644	INIT_LIST_HEAD(&con->out_queue);
 645	INIT_LIST_HEAD(&con->out_sent);
 646	INIT_DELAYED_WORK(&con->work, ceph_con_workfn);
 647
 648	con->state = CEPH_CON_S_CLOSED;
 649}
 650EXPORT_SYMBOL(ceph_con_init);
 651
 652/*
 653 * We maintain a global counter to order connection attempts.  Get
 654 * a unique seq greater than @gt.
 655 */
 656u32 ceph_get_global_seq(struct ceph_messenger *msgr, u32 gt)
 657{
 658	u32 ret;
 659
 660	spin_lock(&msgr->global_seq_lock);
 661	if (msgr->global_seq < gt)
 662		msgr->global_seq = gt;
 663	ret = ++msgr->global_seq;
 664	spin_unlock(&msgr->global_seq_lock);
 665	return ret;
 666}
 667
 668/*
 669 * Discard messages that have been acked by the server.
 670 */
 671void ceph_con_discard_sent(struct ceph_connection *con, u64 ack_seq)
 672{
 673	struct ceph_msg *msg;
 674	u64 seq;
 675
 676	dout("%s con %p ack_seq %llu\n", __func__, con, ack_seq);
 677	while (!list_empty(&con->out_sent)) {
 678		msg = list_first_entry(&con->out_sent, struct ceph_msg,
 679				       list_head);
 680		WARN_ON(msg->needs_out_seq);
 681		seq = le64_to_cpu(msg->hdr.seq);
 682		if (seq > ack_seq)
 683			break;
 684
 685		dout("%s con %p discarding msg %p seq %llu\n", __func__, con,
 686		     msg, seq);
 687		ceph_msg_remove(msg);
 688	}
 689}
 690
 691/*
 692 * Discard messages that have been requeued in con_fault(), up to
 693 * reconnect_seq.  This avoids gratuitously resending messages that
 694 * the server had received and handled prior to reconnect.
 695 */
 696void ceph_con_discard_requeued(struct ceph_connection *con, u64 reconnect_seq)
 697{
 698	struct ceph_msg *msg;
 699	u64 seq;
 700
 701	dout("%s con %p reconnect_seq %llu\n", __func__, con, reconnect_seq);
 702	while (!list_empty(&con->out_queue)) {
 703		msg = list_first_entry(&con->out_queue, struct ceph_msg,
 704				       list_head);
 705		if (msg->needs_out_seq)
 706			break;
 707		seq = le64_to_cpu(msg->hdr.seq);
 708		if (seq > reconnect_seq)
 709			break;
 710
 711		dout("%s con %p discarding msg %p seq %llu\n", __func__, con,
 712		     msg, seq);
 713		ceph_msg_remove(msg);
 714	}
 715}
 716
 717#ifdef CONFIG_BLOCK
 718
 719/*
 720 * For a bio data item, a piece is whatever remains of the next
 721 * entry in the current bio iovec, or the first entry in the next
 722 * bio in the list.
 723 */
 724static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data_cursor *cursor,
 725					size_t length)
 726{
 727	struct ceph_msg_data *data = cursor->data;
 728	struct ceph_bio_iter *it = &cursor->bio_iter;
 729
 730	cursor->resid = min_t(size_t, length, data->bio_length);
 731	*it = data->bio_pos;
 732	if (cursor->resid < it->iter.bi_size)
 733		it->iter.bi_size = cursor->resid;
 734
 735	BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
 736}
 737
 738static struct page *ceph_msg_data_bio_next(struct ceph_msg_data_cursor *cursor,
 739						size_t *page_offset,
 740						size_t *length)
 741{
 742	struct bio_vec bv = bio_iter_iovec(cursor->bio_iter.bio,
 743					   cursor->bio_iter.iter);
 744
 745	*page_offset = bv.bv_offset;
 746	*length = bv.bv_len;
 747	return bv.bv_page;
 748}
 749
 750static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
 751					size_t bytes)
 752{
 753	struct ceph_bio_iter *it = &cursor->bio_iter;
 754	struct page *page = bio_iter_page(it->bio, it->iter);
 755
 756	BUG_ON(bytes > cursor->resid);
 757	BUG_ON(bytes > bio_iter_len(it->bio, it->iter));
 758	cursor->resid -= bytes;
 759	bio_advance_iter(it->bio, &it->iter, bytes);
 760
 761	if (!cursor->resid)
 762		return false;   /* no more data */
 763
 764	if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done &&
 765		       page == bio_iter_page(it->bio, it->iter)))
 766		return false;	/* more bytes to process in this segment */
 767
 768	if (!it->iter.bi_size) {
 769		it->bio = it->bio->bi_next;
 770		it->iter = it->bio->bi_iter;
 771		if (cursor->resid < it->iter.bi_size)
 772			it->iter.bi_size = cursor->resid;
 773	}
 774
 775	BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
 776	return true;
 777}
 778#endif /* CONFIG_BLOCK */
 779
 780static void ceph_msg_data_bvecs_cursor_init(struct ceph_msg_data_cursor *cursor,
 781					size_t length)
 782{
 783	struct ceph_msg_data *data = cursor->data;
 784	struct bio_vec *bvecs = data->bvec_pos.bvecs;
 785
 786	cursor->resid = min_t(size_t, length, data->bvec_pos.iter.bi_size);
 787	cursor->bvec_iter = data->bvec_pos.iter;
 788	cursor->bvec_iter.bi_size = cursor->resid;
 789
 790	BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
 791}
 792
 793static struct page *ceph_msg_data_bvecs_next(struct ceph_msg_data_cursor *cursor,
 794						size_t *page_offset,
 795						size_t *length)
 796{
 797	struct bio_vec bv = bvec_iter_bvec(cursor->data->bvec_pos.bvecs,
 798					   cursor->bvec_iter);
 799
 800	*page_offset = bv.bv_offset;
 801	*length = bv.bv_len;
 802	return bv.bv_page;
 803}
 804
 805static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
 806					size_t bytes)
 807{
 808	struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
 809	struct page *page = bvec_iter_page(bvecs, cursor->bvec_iter);
 810
 811	BUG_ON(bytes > cursor->resid);
 812	BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
 813	cursor->resid -= bytes;
 814	bvec_iter_advance(bvecs, &cursor->bvec_iter, bytes);
 815
 816	if (!cursor->resid)
 817		return false;   /* no more data */
 818
 819	if (!bytes || (cursor->bvec_iter.bi_bvec_done &&
 820		       page == bvec_iter_page(bvecs, cursor->bvec_iter)))
 821		return false;	/* more bytes to process in this segment */
 822
 823	BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
 824	return true;
 825}
 826
 827/*
 828 * For a page array, a piece comes from the first page in the array
 829 * that has not already been fully consumed.
 830 */
 831static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
 832					size_t length)
 833{
 834	struct ceph_msg_data *data = cursor->data;
 835	int page_count;
 836
 837	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
 838
 839	BUG_ON(!data->pages);
 840	BUG_ON(!data->length);
 841
 842	cursor->resid = min(length, data->length);
 843	page_count = calc_pages_for(data->alignment, (u64)data->length);
 844	cursor->page_offset = data->alignment & ~PAGE_MASK;
 845	cursor->page_index = 0;
 846	BUG_ON(page_count > (int)USHRT_MAX);
 847	cursor->page_count = (unsigned short)page_count;
 848	BUG_ON(length > SIZE_MAX - cursor->page_offset);
 849}
 850
 851static struct page *
 852ceph_msg_data_pages_next(struct ceph_msg_data_cursor *cursor,
 853					size_t *page_offset, size_t *length)
 854{
 855	struct ceph_msg_data *data = cursor->data;
 856
 857	BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
 858
 859	BUG_ON(cursor->page_index >= cursor->page_count);
 860	BUG_ON(cursor->page_offset >= PAGE_SIZE);
 861
 862	*page_offset = cursor->page_offset;
 863	*length = min_t(size_t, cursor->resid, PAGE_SIZE - *page_offset);
 864	return data->pages[cursor->page_index];
 865}
 866
 867static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
 868						size_t bytes)
 869{
 870	BUG_ON(cursor->data->type != CEPH_MSG_DATA_PAGES);
 871
 872	BUG_ON(cursor->page_offset + bytes > PAGE_SIZE);
 873
 874	/* Advance the cursor page offset */
 875
 876	cursor->resid -= bytes;
 877	cursor->page_offset = (cursor->page_offset + bytes) & ~PAGE_MASK;
 878	if (!bytes || cursor->page_offset)
 879		return false;	/* more bytes to process in the current page */
 880
 881	if (!cursor->resid)
 882		return false;   /* no more data */
 883
 884	/* Move on to the next page; offset is already at 0 */
 885
 886	BUG_ON(cursor->page_index >= cursor->page_count);
 887	cursor->page_index++;
 888	return true;
 889}
 890
 891/*
 892 * For a pagelist, a piece is whatever remains to be consumed in the
 893 * first page in the list, or the front of the next page.
 894 */
 895static void
 896ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data_cursor *cursor,
 897					size_t length)
 898{
 899	struct ceph_msg_data *data = cursor->data;
 900	struct ceph_pagelist *pagelist;
 901	struct page *page;
 902
 903	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
 904
 905	pagelist = data->pagelist;
 906	BUG_ON(!pagelist);
 907
 908	if (!length)
 909		return;		/* pagelist can be assigned but empty */
 910
 911	BUG_ON(list_empty(&pagelist->head));
 912	page = list_first_entry(&pagelist->head, struct page, lru);
 913
 914	cursor->resid = min(length, pagelist->length);
 915	cursor->page = page;
 916	cursor->offset = 0;
 917}
 918
 919static struct page *
 920ceph_msg_data_pagelist_next(struct ceph_msg_data_cursor *cursor,
 921				size_t *page_offset, size_t *length)
 922{
 923	struct ceph_msg_data *data = cursor->data;
 924	struct ceph_pagelist *pagelist;
 925
 926	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
 927
 928	pagelist = data->pagelist;
 929	BUG_ON(!pagelist);
 930
 931	BUG_ON(!cursor->page);
 932	BUG_ON(cursor->offset + cursor->resid != pagelist->length);
 933
 934	/* offset of first page in pagelist is always 0 */
 935	*page_offset = cursor->offset & ~PAGE_MASK;
 936	*length = min_t(size_t, cursor->resid, PAGE_SIZE - *page_offset);
 937	return cursor->page;
 938}
 939
 940static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data_cursor *cursor,
 941						size_t bytes)
 942{
 943	struct ceph_msg_data *data = cursor->data;
 944	struct ceph_pagelist *pagelist;
 945
 946	BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
 947
 948	pagelist = data->pagelist;
 949	BUG_ON(!pagelist);
 950
 951	BUG_ON(cursor->offset + cursor->resid != pagelist->length);
 952	BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE);
 953
 954	/* Advance the cursor offset */
 955
 956	cursor->resid -= bytes;
 957	cursor->offset += bytes;
 958	/* offset of first page in pagelist is always 0 */
 959	if (!bytes || cursor->offset & ~PAGE_MASK)
 960		return false;	/* more bytes to process in the current page */
 961
 962	if (!cursor->resid)
 963		return false;   /* no more data */
 964
 965	/* Move on to the next page */
 966
 967	BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head));
 968	cursor->page = list_next_entry(cursor->page, lru);
 969	return true;
 970}
 971
 972static void ceph_msg_data_iter_cursor_init(struct ceph_msg_data_cursor *cursor,
 973					   size_t length)
 974{
 975	struct ceph_msg_data *data = cursor->data;
 976
 977	cursor->iov_iter = data->iter;
 978	cursor->lastlen = 0;
 979	iov_iter_truncate(&cursor->iov_iter, length);
 980	cursor->resid = iov_iter_count(&cursor->iov_iter);
 981}
 982
 983static struct page *ceph_msg_data_iter_next(struct ceph_msg_data_cursor *cursor,
 984					    size_t *page_offset, size_t *length)
 985{
 986	struct page *page;
 987	ssize_t len;
 988
 989	if (cursor->lastlen)
 990		iov_iter_revert(&cursor->iov_iter, cursor->lastlen);
 991
 992	len = iov_iter_get_pages2(&cursor->iov_iter, &page, PAGE_SIZE,
 993				  1, page_offset);
 994	BUG_ON(len < 0);
 995
 996	cursor->lastlen = len;
 997
 998	/*
 999	 * FIXME: The assumption is that the pages represented by the iov_iter
1000	 *	  are pinned, with the references held by the upper-level
1001	 *	  callers, or by virtue of being under writeback. Eventually,
1002	 *	  we'll get an iov_iter_get_pages2 variant that doesn't take
1003	 *	  page refs. Until then, just put the page ref.
1004	 */
1005	VM_BUG_ON_PAGE(!PageWriteback(page) && page_count(page) < 2, page);
1006	put_page(page);
1007
1008	*length = min_t(size_t, len, cursor->resid);
1009	return page;
1010}
1011
1012static bool ceph_msg_data_iter_advance(struct ceph_msg_data_cursor *cursor,
1013				       size_t bytes)
1014{
1015	BUG_ON(bytes > cursor->resid);
1016	cursor->resid -= bytes;
1017
1018	if (bytes < cursor->lastlen) {
1019		cursor->lastlen -= bytes;
1020	} else {
1021		iov_iter_advance(&cursor->iov_iter, bytes - cursor->lastlen);
1022		cursor->lastlen = 0;
1023	}
1024
1025	return cursor->resid;
1026}
1027
1028/*
1029 * Message data is handled (sent or received) in pieces, where each
1030 * piece resides on a single page.  The network layer might not
1031 * consume an entire piece at once.  A data item's cursor keeps
1032 * track of which piece is next to process and how much remains to
1033 * be processed in that piece.  It also tracks whether the current
1034 * piece is the last one in the data item.
1035 */
1036static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
1037{
1038	size_t length = cursor->total_resid;
1039
1040	switch (cursor->data->type) {
1041	case CEPH_MSG_DATA_PAGELIST:
1042		ceph_msg_data_pagelist_cursor_init(cursor, length);
1043		break;
1044	case CEPH_MSG_DATA_PAGES:
1045		ceph_msg_data_pages_cursor_init(cursor, length);
1046		break;
1047#ifdef CONFIG_BLOCK
1048	case CEPH_MSG_DATA_BIO:
1049		ceph_msg_data_bio_cursor_init(cursor, length);
1050		break;
1051#endif /* CONFIG_BLOCK */
1052	case CEPH_MSG_DATA_BVECS:
1053		ceph_msg_data_bvecs_cursor_init(cursor, length);
1054		break;
1055	case CEPH_MSG_DATA_ITER:
1056		ceph_msg_data_iter_cursor_init(cursor, length);
1057		break;
1058	case CEPH_MSG_DATA_NONE:
1059	default:
1060		/* BUG(); */
1061		break;
1062	}
1063	cursor->need_crc = true;
1064}
1065
1066void ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor,
1067			       struct ceph_msg *msg, size_t length)
1068{
1069	BUG_ON(!length);
1070	BUG_ON(length > msg->data_length);
1071	BUG_ON(!msg->num_data_items);
1072
1073	cursor->total_resid = length;
1074	cursor->data = msg->data;
1075	cursor->sr_resid = 0;
1076
1077	__ceph_msg_data_cursor_init(cursor);
1078}
1079
1080/*
1081 * Return the page containing the next piece to process for a given
1082 * data item, and supply the page offset and length of that piece.
1083 * Indicate whether this is the last piece in this data item.
1084 */
1085struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
1086				size_t *page_offset, size_t *length)
1087{
1088	struct page *page;
1089
1090	switch (cursor->data->type) {
1091	case CEPH_MSG_DATA_PAGELIST:
1092		page = ceph_msg_data_pagelist_next(cursor, page_offset, length);
1093		break;
1094	case CEPH_MSG_DATA_PAGES:
1095		page = ceph_msg_data_pages_next(cursor, page_offset, length);
1096		break;
1097#ifdef CONFIG_BLOCK
1098	case CEPH_MSG_DATA_BIO:
1099		page = ceph_msg_data_bio_next(cursor, page_offset, length);
1100		break;
1101#endif /* CONFIG_BLOCK */
1102	case CEPH_MSG_DATA_BVECS:
1103		page = ceph_msg_data_bvecs_next(cursor, page_offset, length);
1104		break;
1105	case CEPH_MSG_DATA_ITER:
1106		page = ceph_msg_data_iter_next(cursor, page_offset, length);
1107		break;
1108	case CEPH_MSG_DATA_NONE:
1109	default:
1110		page = NULL;
1111		break;
1112	}
1113
1114	BUG_ON(!page);
1115	BUG_ON(*page_offset + *length > PAGE_SIZE);
1116	BUG_ON(!*length);
1117	BUG_ON(*length > cursor->resid);
1118
1119	return page;
1120}
1121
1122/*
1123 * Returns true if the result moves the cursor on to the next piece
1124 * of the data item.
1125 */
1126void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor, size_t bytes)
1127{
1128	bool new_piece;
1129
1130	BUG_ON(bytes > cursor->resid);
1131	switch (cursor->data->type) {
1132	case CEPH_MSG_DATA_PAGELIST:
1133		new_piece = ceph_msg_data_pagelist_advance(cursor, bytes);
1134		break;
1135	case CEPH_MSG_DATA_PAGES:
1136		new_piece = ceph_msg_data_pages_advance(cursor, bytes);
1137		break;
1138#ifdef CONFIG_BLOCK
1139	case CEPH_MSG_DATA_BIO:
1140		new_piece = ceph_msg_data_bio_advance(cursor, bytes);
1141		break;
1142#endif /* CONFIG_BLOCK */
1143	case CEPH_MSG_DATA_BVECS:
1144		new_piece = ceph_msg_data_bvecs_advance(cursor, bytes);
1145		break;
1146	case CEPH_MSG_DATA_ITER:
1147		new_piece = ceph_msg_data_iter_advance(cursor, bytes);
1148		break;
1149	case CEPH_MSG_DATA_NONE:
1150	default:
1151		BUG();
1152		break;
1153	}
1154	cursor->total_resid -= bytes;
1155
1156	if (!cursor->resid && cursor->total_resid) {
1157		cursor->data++;
1158		__ceph_msg_data_cursor_init(cursor);
1159		new_piece = true;
1160	}
1161	cursor->need_crc = new_piece;
1162}
1163
1164u32 ceph_crc32c_page(u32 crc, struct page *page, unsigned int page_offset,
1165		     unsigned int length)
1166{
1167	char *kaddr;
1168
1169	kaddr = kmap(page);
1170	BUG_ON(kaddr == NULL);
1171	crc = crc32c(crc, kaddr + page_offset, length);
1172	kunmap(page);
1173
1174	return crc;
1175}
1176
1177bool ceph_addr_is_blank(const struct ceph_entity_addr *addr)
1178{
1179	struct sockaddr_storage ss = addr->in_addr; /* align */
1180	struct in_addr *addr4 = &((struct sockaddr_in *)&ss)->sin_addr;
1181	struct in6_addr *addr6 = &((struct sockaddr_in6 *)&ss)->sin6_addr;
1182
1183	switch (ss.ss_family) {
1184	case AF_INET:
1185		return addr4->s_addr == htonl(INADDR_ANY);
1186	case AF_INET6:
1187		return ipv6_addr_any(addr6);
1188	default:
1189		return true;
1190	}
1191}
1192EXPORT_SYMBOL(ceph_addr_is_blank);
1193
1194int ceph_addr_port(const struct ceph_entity_addr *addr)
1195{
1196	switch (get_unaligned(&addr->in_addr.ss_family)) {
1197	case AF_INET:
1198		return ntohs(get_unaligned(&((struct sockaddr_in *)&addr->in_addr)->sin_port));
1199	case AF_INET6:
1200		return ntohs(get_unaligned(&((struct sockaddr_in6 *)&addr->in_addr)->sin6_port));
1201	}
1202	return 0;
1203}
1204
1205void ceph_addr_set_port(struct ceph_entity_addr *addr, int p)
1206{
1207	switch (get_unaligned(&addr->in_addr.ss_family)) {
1208	case AF_INET:
1209		put_unaligned(htons(p), &((struct sockaddr_in *)&addr->in_addr)->sin_port);
1210		break;
1211	case AF_INET6:
1212		put_unaligned(htons(p), &((struct sockaddr_in6 *)&addr->in_addr)->sin6_port);
1213		break;
1214	}
1215}
1216
1217/*
1218 * Unlike other *_pton function semantics, zero indicates success.
1219 */
1220static int ceph_pton(const char *str, size_t len, struct ceph_entity_addr *addr,
1221		char delim, const char **ipend)
1222{
1223	memset(&addr->in_addr, 0, sizeof(addr->in_addr));
1224
1225	if (in4_pton(str, len, (u8 *)&((struct sockaddr_in *)&addr->in_addr)->sin_addr.s_addr, delim, ipend)) {
1226		put_unaligned(AF_INET, &addr->in_addr.ss_family);
1227		return 0;
1228	}
1229
1230	if (in6_pton(str, len, (u8 *)&((struct sockaddr_in6 *)&addr->in_addr)->sin6_addr.s6_addr, delim, ipend)) {
1231		put_unaligned(AF_INET6, &addr->in_addr.ss_family);
1232		return 0;
1233	}
1234
1235	return -EINVAL;
1236}
1237
1238/*
1239 * Extract hostname string and resolve using kernel DNS facility.
1240 */
1241#ifdef CONFIG_CEPH_LIB_USE_DNS_RESOLVER
1242static int ceph_dns_resolve_name(const char *name, size_t namelen,
1243		struct ceph_entity_addr *addr, char delim, const char **ipend)
1244{
1245	const char *end, *delim_p;
1246	char *colon_p, *ip_addr = NULL;
1247	int ip_len, ret;
1248
1249	/*
1250	 * The end of the hostname occurs immediately preceding the delimiter or
1251	 * the port marker (':') where the delimiter takes precedence.
1252	 */
1253	delim_p = memchr(name, delim, namelen);
1254	colon_p = memchr(name, ':', namelen);
1255
1256	if (delim_p && colon_p)
1257		end = min(delim_p, colon_p);
1258	else if (!delim_p && colon_p)
1259		end = colon_p;
1260	else {
1261		end = delim_p;
1262		if (!end) /* case: hostname:/ */
1263			end = name + namelen;
1264	}
1265
1266	if (end <= name)
1267		return -EINVAL;
1268
1269	/* do dns_resolve upcall */
1270	ip_len = dns_query(current->nsproxy->net_ns,
1271			   NULL, name, end - name, NULL, &ip_addr, NULL, false);
1272	if (ip_len > 0)
1273		ret = ceph_pton(ip_addr, ip_len, addr, -1, NULL);
1274	else
1275		ret = -ESRCH;
1276
1277	kfree(ip_addr);
1278
1279	*ipend = end;
1280
1281	pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name,
1282			ret, ret ? "failed" : ceph_pr_addr(addr));
1283
1284	return ret;
1285}
1286#else
1287static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
1288		struct ceph_entity_addr *addr, char delim, const char **ipend)
1289{
1290	return -EINVAL;
1291}
1292#endif
1293
1294/*
1295 * Parse a server name (IP or hostname). If a valid IP address is not found
1296 * then try to extract a hostname to resolve using userspace DNS upcall.
1297 */
1298static int ceph_parse_server_name(const char *name, size_t namelen,
1299		struct ceph_entity_addr *addr, char delim, const char **ipend)
1300{
1301	int ret;
1302
1303	ret = ceph_pton(name, namelen, addr, delim, ipend);
1304	if (ret)
1305		ret = ceph_dns_resolve_name(name, namelen, addr, delim, ipend);
1306
1307	return ret;
1308}
1309
1310/*
1311 * Parse an ip[:port] list into an addr array.  Use the default
1312 * monitor port if a port isn't specified.
1313 */
1314int ceph_parse_ips(const char *c, const char *end,
1315		   struct ceph_entity_addr *addr,
1316		   int max_count, int *count, char delim)
1317{
1318	int i, ret = -EINVAL;
1319	const char *p = c;
1320
1321	dout("parse_ips on '%.*s'\n", (int)(end-c), c);
1322	for (i = 0; i < max_count; i++) {
1323		char cur_delim = delim;
1324		const char *ipend;
1325		int port;
1326
1327		if (*p == '[') {
1328			cur_delim = ']';
1329			p++;
1330		}
1331
1332		ret = ceph_parse_server_name(p, end - p, &addr[i], cur_delim,
1333					     &ipend);
1334		if (ret)
1335			goto bad;
1336		ret = -EINVAL;
1337
1338		p = ipend;
1339
1340		if (cur_delim == ']') {
1341			if (*p != ']') {
1342				dout("missing matching ']'\n");
1343				goto bad;
1344			}
1345			p++;
1346		}
1347
1348		/* port? */
1349		if (p < end && *p == ':') {
1350			port = 0;
1351			p++;
1352			while (p < end && *p >= '0' && *p <= '9') {
1353				port = (port * 10) + (*p - '0');
1354				p++;
1355			}
1356			if (port == 0)
1357				port = CEPH_MON_PORT;
1358			else if (port > 65535)
1359				goto bad;
1360		} else {
1361			port = CEPH_MON_PORT;
1362		}
1363
1364		ceph_addr_set_port(&addr[i], port);
1365		/*
1366		 * We want the type to be set according to ms_mode
1367		 * option, but options are normally parsed after mon
1368		 * addresses.  Rather than complicating parsing, set
1369		 * to LEGACY and override in build_initial_monmap()
1370		 * for mon addresses and ceph_messenger_init() for
1371		 * ip option.
1372		 */
1373		addr[i].type = CEPH_ENTITY_ADDR_TYPE_LEGACY;
1374		addr[i].nonce = 0;
1375
1376		dout("%s got %s\n", __func__, ceph_pr_addr(&addr[i]));
1377
1378		if (p == end)
1379			break;
1380		if (*p != delim)
1381			goto bad;
1382		p++;
1383	}
1384
1385	if (p != end)
1386		goto bad;
1387
1388	if (count)
1389		*count = i + 1;
1390	return 0;
1391
1392bad:
1393	return ret;
1394}
1395
1396/*
1397 * Process message.  This happens in the worker thread.  The callback should
1398 * be careful not to do anything that waits on other incoming messages or it
1399 * may deadlock.
1400 */
1401void ceph_con_process_message(struct ceph_connection *con)
1402{
1403	struct ceph_msg *msg = con->in_msg;
1404
1405	BUG_ON(con->in_msg->con != con);
1406	con->in_msg = NULL;
1407
1408	/* if first message, set peer_name */
1409	if (con->peer_name.type == 0)
1410		con->peer_name = msg->hdr.src;
1411
1412	con->in_seq++;
1413	mutex_unlock(&con->mutex);
1414
1415	dout("===== %p %llu from %s%lld %d=%s len %d+%d+%d (%u %u %u) =====\n",
1416	     msg, le64_to_cpu(msg->hdr.seq),
1417	     ENTITY_NAME(msg->hdr.src),
1418	     le16_to_cpu(msg->hdr.type),
1419	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
1420	     le32_to_cpu(msg->hdr.front_len),
1421	     le32_to_cpu(msg->hdr.middle_len),
1422	     le32_to_cpu(msg->hdr.data_len),
1423	     con->in_front_crc, con->in_middle_crc, con->in_data_crc);
1424	con->ops->dispatch(con, msg);
1425
1426	mutex_lock(&con->mutex);
1427}
1428
1429/*
1430 * Atomically queue work on a connection after the specified delay.
1431 * Bump @con reference to avoid races with connection teardown.
1432 * Returns 0 if work was queued, or an error code otherwise.
1433 */
1434static int queue_con_delay(struct ceph_connection *con, unsigned long delay)
1435{
1436	if (!con->ops->get(con)) {
1437		dout("%s %p ref count 0\n", __func__, con);
1438		return -ENOENT;
1439	}
1440
1441	if (delay >= HZ)
1442		delay = round_jiffies_relative(delay);
1443
1444	dout("%s %p %lu\n", __func__, con, delay);
1445	if (!queue_delayed_work(ceph_msgr_wq, &con->work, delay)) {
1446		dout("%s %p - already queued\n", __func__, con);
1447		con->ops->put(con);
1448		return -EBUSY;
1449	}
1450
1451	return 0;
1452}
1453
1454static void queue_con(struct ceph_connection *con)
1455{
1456	(void) queue_con_delay(con, 0);
1457}
1458
1459static void cancel_con(struct ceph_connection *con)
1460{
1461	if (cancel_delayed_work(&con->work)) {
1462		dout("%s %p\n", __func__, con);
1463		con->ops->put(con);
1464	}
1465}
1466
1467static bool con_sock_closed(struct ceph_connection *con)
1468{
1469	if (!ceph_con_flag_test_and_clear(con, CEPH_CON_F_SOCK_CLOSED))
1470		return false;
1471
1472#define CASE(x)								\
1473	case CEPH_CON_S_ ## x:						\
1474		con->error_msg = "socket closed (con state " #x ")";	\
1475		break;
1476
1477	switch (con->state) {
1478	CASE(CLOSED);
1479	CASE(PREOPEN);
1480	CASE(V1_BANNER);
1481	CASE(V1_CONNECT_MSG);
1482	CASE(V2_BANNER_PREFIX);
1483	CASE(V2_BANNER_PAYLOAD);
1484	CASE(V2_HELLO);
1485	CASE(V2_AUTH);
1486	CASE(V2_AUTH_SIGNATURE);
1487	CASE(V2_SESSION_CONNECT);
1488	CASE(V2_SESSION_RECONNECT);
1489	CASE(OPEN);
1490	CASE(STANDBY);
1491	default:
1492		BUG();
1493	}
1494#undef CASE
1495
1496	return true;
1497}
1498
1499static bool con_backoff(struct ceph_connection *con)
1500{
1501	int ret;
1502
1503	if (!ceph_con_flag_test_and_clear(con, CEPH_CON_F_BACKOFF))
1504		return false;
1505
1506	ret = queue_con_delay(con, con->delay);
1507	if (ret) {
1508		dout("%s: con %p FAILED to back off %lu\n", __func__,
1509			con, con->delay);
1510		BUG_ON(ret == -ENOENT);
1511		ceph_con_flag_set(con, CEPH_CON_F_BACKOFF);
1512	}
1513
1514	return true;
1515}
1516
1517/* Finish fault handling; con->mutex must *not* be held here */
1518
1519static void con_fault_finish(struct ceph_connection *con)
1520{
1521	dout("%s %p\n", __func__, con);
1522
1523	/*
1524	 * in case we faulted due to authentication, invalidate our
1525	 * current tickets so that we can get new ones.
1526	 */
1527	if (con->v1.auth_retry) {
1528		dout("auth_retry %d, invalidating\n", con->v1.auth_retry);
1529		if (con->ops->invalidate_authorizer)
1530			con->ops->invalidate_authorizer(con);
1531		con->v1.auth_retry = 0;
1532	}
1533
1534	if (con->ops->fault)
1535		con->ops->fault(con);
1536}
1537
1538/*
1539 * Do some work on a connection.  Drop a connection ref when we're done.
1540 */
1541static void ceph_con_workfn(struct work_struct *work)
1542{
1543	struct ceph_connection *con = container_of(work, struct ceph_connection,
1544						   work.work);
1545	bool fault;
1546
1547	mutex_lock(&con->mutex);
1548	while (true) {
1549		int ret;
1550
1551		if ((fault = con_sock_closed(con))) {
1552			dout("%s: con %p SOCK_CLOSED\n", __func__, con);
1553			break;
1554		}
1555		if (con_backoff(con)) {
1556			dout("%s: con %p BACKOFF\n", __func__, con);
1557			break;
1558		}
1559		if (con->state == CEPH_CON_S_STANDBY) {
1560			dout("%s: con %p STANDBY\n", __func__, con);
1561			break;
1562		}
1563		if (con->state == CEPH_CON_S_CLOSED) {
1564			dout("%s: con %p CLOSED\n", __func__, con);
1565			BUG_ON(con->sock);
1566			break;
1567		}
1568		if (con->state == CEPH_CON_S_PREOPEN) {
1569			dout("%s: con %p PREOPEN\n", __func__, con);
1570			BUG_ON(con->sock);
1571		}
1572
1573		if (ceph_msgr2(from_msgr(con->msgr)))
1574			ret = ceph_con_v2_try_read(con);
1575		else
1576			ret = ceph_con_v1_try_read(con);
1577		if (ret < 0) {
1578			if (ret == -EAGAIN)
1579				continue;
1580			if (!con->error_msg)
1581				con->error_msg = "socket error on read";
1582			fault = true;
1583			break;
1584		}
1585
1586		if (ceph_msgr2(from_msgr(con->msgr)))
1587			ret = ceph_con_v2_try_write(con);
1588		else
1589			ret = ceph_con_v1_try_write(con);
1590		if (ret < 0) {
1591			if (ret == -EAGAIN)
1592				continue;
1593			if (!con->error_msg)
1594				con->error_msg = "socket error on write";
1595			fault = true;
1596		}
1597
1598		break;	/* If we make it to here, we're done */
1599	}
1600	if (fault)
1601		con_fault(con);
1602	mutex_unlock(&con->mutex);
1603
1604	if (fault)
1605		con_fault_finish(con);
1606
1607	con->ops->put(con);
1608}
1609
1610/*
1611 * Generic error/fault handler.  A retry mechanism is used with
1612 * exponential backoff
1613 */
1614static void con_fault(struct ceph_connection *con)
1615{
1616	dout("fault %p state %d to peer %s\n",
1617	     con, con->state, ceph_pr_addr(&con->peer_addr));
1618
1619	pr_warn("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
1620		ceph_pr_addr(&con->peer_addr), con->error_msg);
1621	con->error_msg = NULL;
1622
1623	WARN_ON(con->state == CEPH_CON_S_STANDBY ||
1624		con->state == CEPH_CON_S_CLOSED);
1625
1626	ceph_con_reset_protocol(con);
1627
1628	if (ceph_con_flag_test(con, CEPH_CON_F_LOSSYTX)) {
1629		dout("fault on LOSSYTX channel, marking CLOSED\n");
1630		con->state = CEPH_CON_S_CLOSED;
1631		return;
1632	}
1633
1634	/* Requeue anything that hasn't been acked */
1635	list_splice_init(&con->out_sent, &con->out_queue);
1636
1637	/* If there are no messages queued or keepalive pending, place
1638	 * the connection in a STANDBY state */
1639	if (list_empty(&con->out_queue) &&
1640	    !ceph_con_flag_test(con, CEPH_CON_F_KEEPALIVE_PENDING)) {
1641		dout("fault %p setting STANDBY clearing WRITE_PENDING\n", con);
1642		ceph_con_flag_clear(con, CEPH_CON_F_WRITE_PENDING);
1643		con->state = CEPH_CON_S_STANDBY;
1644	} else {
1645		/* retry after a delay. */
1646		con->state = CEPH_CON_S_PREOPEN;
1647		if (!con->delay) {
1648			con->delay = BASE_DELAY_INTERVAL;
1649		} else if (con->delay < MAX_DELAY_INTERVAL) {
1650			con->delay *= 2;
1651			if (con->delay > MAX_DELAY_INTERVAL)
1652				con->delay = MAX_DELAY_INTERVAL;
1653		}
1654		ceph_con_flag_set(con, CEPH_CON_F_BACKOFF);
1655		queue_con(con);
1656	}
1657}
1658
1659void ceph_messenger_reset_nonce(struct ceph_messenger *msgr)
1660{
1661	u32 nonce = le32_to_cpu(msgr->inst.addr.nonce) + 1000000;
1662	msgr->inst.addr.nonce = cpu_to_le32(nonce);
1663	ceph_encode_my_addr(msgr);
1664}
1665
1666/*
1667 * initialize a new messenger instance
1668 */
1669void ceph_messenger_init(struct ceph_messenger *msgr,
1670			 struct ceph_entity_addr *myaddr)
1671{
1672	spin_lock_init(&msgr->global_seq_lock);
1673
1674	if (myaddr) {
1675		memcpy(&msgr->inst.addr.in_addr, &myaddr->in_addr,
1676		       sizeof(msgr->inst.addr.in_addr));
1677		ceph_addr_set_port(&msgr->inst.addr, 0);
1678	}
1679
1680	/*
1681	 * Since nautilus, clients are identified using type ANY.
1682	 * For msgr1, ceph_encode_banner_addr() munges it to NONE.
1683	 */
1684	msgr->inst.addr.type = CEPH_ENTITY_ADDR_TYPE_ANY;
1685
1686	/* generate a random non-zero nonce */
1687	do {
1688		get_random_bytes(&msgr->inst.addr.nonce,
1689				 sizeof(msgr->inst.addr.nonce));
1690	} while (!msgr->inst.addr.nonce);
1691	ceph_encode_my_addr(msgr);
1692
1693	atomic_set(&msgr->stopping, 0);
1694	write_pnet(&msgr->net, get_net(current->nsproxy->net_ns));
1695
1696	dout("%s %p\n", __func__, msgr);
1697}
1698
1699void ceph_messenger_fini(struct ceph_messenger *msgr)
1700{
1701	put_net(read_pnet(&msgr->net));
1702}
1703
1704static void msg_con_set(struct ceph_msg *msg, struct ceph_connection *con)
1705{
1706	if (msg->con)
1707		msg->con->ops->put(msg->con);
1708
1709	msg->con = con ? con->ops->get(con) : NULL;
1710	BUG_ON(msg->con != con);
1711}
1712
1713static void clear_standby(struct ceph_connection *con)
1714{
1715	/* come back from STANDBY? */
1716	if (con->state == CEPH_CON_S_STANDBY) {
1717		dout("clear_standby %p and ++connect_seq\n", con);
1718		con->state = CEPH_CON_S_PREOPEN;
1719		con->v1.connect_seq++;
1720		WARN_ON(ceph_con_flag_test(con, CEPH_CON_F_WRITE_PENDING));
1721		WARN_ON(ceph_con_flag_test(con, CEPH_CON_F_KEEPALIVE_PENDING));
1722	}
1723}
1724
1725/*
1726 * Queue up an outgoing message on the given connection.
1727 *
1728 * Consumes a ref on @msg.
1729 */
1730void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
1731{
1732	/* set src+dst */
1733	msg->hdr.src = con->msgr->inst.name;
1734	BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
1735	msg->needs_out_seq = true;
1736
1737	mutex_lock(&con->mutex);
1738
1739	if (con->state == CEPH_CON_S_CLOSED) {
1740		dout("con_send %p closed, dropping %p\n", con, msg);
1741		ceph_msg_put(msg);
1742		mutex_unlock(&con->mutex);
1743		return;
1744	}
1745
1746	msg_con_set(msg, con);
1747
1748	BUG_ON(!list_empty(&msg->list_head));
1749	list_add_tail(&msg->list_head, &con->out_queue);
1750	dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
1751	     ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
1752	     ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
1753	     le32_to_cpu(msg->hdr.front_len),
1754	     le32_to_cpu(msg->hdr.middle_len),
1755	     le32_to_cpu(msg->hdr.data_len));
1756
1757	clear_standby(con);
1758	mutex_unlock(&con->mutex);
1759
1760	/* if there wasn't anything waiting to send before, queue
1761	 * new work */
1762	if (!ceph_con_flag_test_and_set(con, CEPH_CON_F_WRITE_PENDING))
1763		queue_con(con);
1764}
1765EXPORT_SYMBOL(ceph_con_send);
1766
1767/*
1768 * Revoke a message that was previously queued for send
1769 */
1770void ceph_msg_revoke(struct ceph_msg *msg)
1771{
1772	struct ceph_connection *con = msg->con;
1773
1774	if (!con) {
1775		dout("%s msg %p null con\n", __func__, msg);
1776		return;		/* Message not in our possession */
1777	}
1778
1779	mutex_lock(&con->mutex);
1780	if (list_empty(&msg->list_head)) {
1781		WARN_ON(con->out_msg == msg);
1782		dout("%s con %p msg %p not linked\n", __func__, con, msg);
1783		mutex_unlock(&con->mutex);
1784		return;
1785	}
1786
1787	dout("%s con %p msg %p was linked\n", __func__, con, msg);
1788	msg->hdr.seq = 0;
1789	ceph_msg_remove(msg);
1790
1791	if (con->out_msg == msg) {
1792		WARN_ON(con->state != CEPH_CON_S_OPEN);
1793		dout("%s con %p msg %p was sending\n", __func__, con, msg);
1794		if (ceph_msgr2(from_msgr(con->msgr)))
1795			ceph_con_v2_revoke(con);
1796		else
1797			ceph_con_v1_revoke(con);
1798		ceph_msg_put(con->out_msg);
1799		con->out_msg = NULL;
1800	} else {
1801		dout("%s con %p msg %p not current, out_msg %p\n", __func__,
1802		     con, msg, con->out_msg);
1803	}
1804	mutex_unlock(&con->mutex);
1805}
1806
1807/*
1808 * Revoke a message that we may be reading data into
1809 */
1810void ceph_msg_revoke_incoming(struct ceph_msg *msg)
1811{
1812	struct ceph_connection *con = msg->con;
1813
1814	if (!con) {
1815		dout("%s msg %p null con\n", __func__, msg);
1816		return;		/* Message not in our possession */
1817	}
1818
1819	mutex_lock(&con->mutex);
1820	if (con->in_msg == msg) {
1821		WARN_ON(con->state != CEPH_CON_S_OPEN);
1822		dout("%s con %p msg %p was recving\n", __func__, con, msg);
1823		if (ceph_msgr2(from_msgr(con->msgr)))
1824			ceph_con_v2_revoke_incoming(con);
1825		else
1826			ceph_con_v1_revoke_incoming(con);
1827		ceph_msg_put(con->in_msg);
1828		con->in_msg = NULL;
1829	} else {
1830		dout("%s con %p msg %p not current, in_msg %p\n", __func__,
1831		     con, msg, con->in_msg);
1832	}
1833	mutex_unlock(&con->mutex);
1834}
1835
1836/*
1837 * Queue a keepalive byte to ensure the tcp connection is alive.
1838 */
1839void ceph_con_keepalive(struct ceph_connection *con)
1840{
1841	dout("con_keepalive %p\n", con);
1842	mutex_lock(&con->mutex);
1843	clear_standby(con);
1844	ceph_con_flag_set(con, CEPH_CON_F_KEEPALIVE_PENDING);
1845	mutex_unlock(&con->mutex);
1846
1847	if (!ceph_con_flag_test_and_set(con, CEPH_CON_F_WRITE_PENDING))
1848		queue_con(con);
1849}
1850EXPORT_SYMBOL(ceph_con_keepalive);
1851
1852bool ceph_con_keepalive_expired(struct ceph_connection *con,
1853			       unsigned long interval)
1854{
1855	if (interval > 0 &&
1856	    (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2)) {
1857		struct timespec64 now;
1858		struct timespec64 ts;
1859		ktime_get_real_ts64(&now);
1860		jiffies_to_timespec64(interval, &ts);
1861		ts = timespec64_add(con->last_keepalive_ack, ts);
1862		return timespec64_compare(&now, &ts) >= 0;
1863	}
1864	return false;
1865}
1866
1867static struct ceph_msg_data *ceph_msg_data_add(struct ceph_msg *msg)
1868{
1869	BUG_ON(msg->num_data_items >= msg->max_data_items);
1870	return &msg->data[msg->num_data_items++];
1871}
1872
1873static void ceph_msg_data_destroy(struct ceph_msg_data *data)
1874{
1875	if (data->type == CEPH_MSG_DATA_PAGES && data->own_pages) {
1876		int num_pages = calc_pages_for(data->alignment, data->length);
1877		ceph_release_page_vector(data->pages, num_pages);
1878	} else if (data->type == CEPH_MSG_DATA_PAGELIST) {
1879		ceph_pagelist_release(data->pagelist);
1880	}
1881}
1882
1883void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
1884			     size_t length, size_t alignment, bool own_pages)
1885{
1886	struct ceph_msg_data *data;
1887
1888	BUG_ON(!pages);
1889	BUG_ON(!length);
1890
1891	data = ceph_msg_data_add(msg);
1892	data->type = CEPH_MSG_DATA_PAGES;
1893	data->pages = pages;
1894	data->length = length;
1895	data->alignment = alignment & ~PAGE_MASK;
1896	data->own_pages = own_pages;
1897
1898	msg->data_length += length;
1899}
1900EXPORT_SYMBOL(ceph_msg_data_add_pages);
1901
1902void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
1903				struct ceph_pagelist *pagelist)
1904{
1905	struct ceph_msg_data *data;
1906
1907	BUG_ON(!pagelist);
1908	BUG_ON(!pagelist->length);
1909
1910	data = ceph_msg_data_add(msg);
1911	data->type = CEPH_MSG_DATA_PAGELIST;
1912	refcount_inc(&pagelist->refcnt);
1913	data->pagelist = pagelist;
1914
1915	msg->data_length += pagelist->length;
1916}
1917EXPORT_SYMBOL(ceph_msg_data_add_pagelist);
1918
1919#ifdef	CONFIG_BLOCK
1920void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
1921			   u32 length)
1922{
1923	struct ceph_msg_data *data;
1924
1925	data = ceph_msg_data_add(msg);
1926	data->type = CEPH_MSG_DATA_BIO;
1927	data->bio_pos = *bio_pos;
1928	data->bio_length = length;
1929
1930	msg->data_length += length;
1931}
1932EXPORT_SYMBOL(ceph_msg_data_add_bio);
1933#endif	/* CONFIG_BLOCK */
1934
1935void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
1936			     struct ceph_bvec_iter *bvec_pos)
1937{
1938	struct ceph_msg_data *data;
1939
1940	data = ceph_msg_data_add(msg);
1941	data->type = CEPH_MSG_DATA_BVECS;
1942	data->bvec_pos = *bvec_pos;
1943
1944	msg->data_length += bvec_pos->iter.bi_size;
1945}
1946EXPORT_SYMBOL(ceph_msg_data_add_bvecs);
1947
1948void ceph_msg_data_add_iter(struct ceph_msg *msg,
1949			    struct iov_iter *iter)
1950{
1951	struct ceph_msg_data *data;
1952
1953	data = ceph_msg_data_add(msg);
1954	data->type = CEPH_MSG_DATA_ITER;
1955	data->iter = *iter;
1956
1957	msg->data_length += iov_iter_count(&data->iter);
1958}
1959
1960/*
1961 * construct a new message with given type, size
1962 * the new msg has a ref count of 1.
1963 */
1964struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
1965			       gfp_t flags, bool can_fail)
1966{
1967	struct ceph_msg *m;
1968
1969	m = kmem_cache_zalloc(ceph_msg_cache, flags);
1970	if (m == NULL)
1971		goto out;
1972
1973	m->hdr.type = cpu_to_le16(type);
1974	m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
1975	m->hdr.front_len = cpu_to_le32(front_len);
1976
1977	INIT_LIST_HEAD(&m->list_head);
1978	kref_init(&m->kref);
1979
1980	/* front */
1981	if (front_len) {
1982		m->front.iov_base = kvmalloc(front_len, flags);
1983		if (m->front.iov_base == NULL) {
1984			dout("ceph_msg_new can't allocate %d bytes\n",
1985			     front_len);
1986			goto out2;
1987		}
1988	} else {
1989		m->front.iov_base = NULL;
1990	}
1991	m->front_alloc_len = m->front.iov_len = front_len;
1992
1993	if (max_data_items) {
1994		m->data = kmalloc_array(max_data_items, sizeof(*m->data),
1995					flags);
1996		if (!m->data)
1997			goto out2;
1998
1999		m->max_data_items = max_data_items;
2000	}
2001
2002	dout("ceph_msg_new %p front %d\n", m, front_len);
2003	return m;
2004
2005out2:
2006	ceph_msg_put(m);
2007out:
2008	if (!can_fail) {
2009		pr_err("msg_new can't create type %d front %d\n", type,
2010		       front_len);
2011		WARN_ON(1);
2012	} else {
2013		dout("msg_new can't create type %d front %d\n", type,
2014		     front_len);
2015	}
2016	return NULL;
2017}
2018EXPORT_SYMBOL(ceph_msg_new2);
2019
2020struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
2021			      bool can_fail)
2022{
2023	return ceph_msg_new2(type, front_len, 0, flags, can_fail);
2024}
2025EXPORT_SYMBOL(ceph_msg_new);
2026
2027/*
2028 * Allocate "middle" portion of a message, if it is needed and wasn't
2029 * allocated by alloc_msg.  This allows us to read a small fixed-size
2030 * per-type header in the front and then gracefully fail (i.e.,
2031 * propagate the error to the caller based on info in the front) when
2032 * the middle is too large.
2033 */
2034static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
2035{
2036	int type = le16_to_cpu(msg->hdr.type);
2037	int middle_len = le32_to_cpu(msg->hdr.middle_len);
2038
2039	dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
2040	     ceph_msg_type_name(type), middle_len);
2041	BUG_ON(!middle_len);
2042	BUG_ON(msg->middle);
2043
2044	msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
2045	if (!msg->middle)
2046		return -ENOMEM;
2047	return 0;
2048}
2049
2050/*
2051 * Allocate a message for receiving an incoming message on a
2052 * connection, and save the result in con->in_msg.  Uses the
2053 * connection's private alloc_msg op if available.
2054 *
2055 * Returns 0 on success, or a negative error code.
2056 *
2057 * On success, if we set *skip = 1:
2058 *  - the next message should be skipped and ignored.
2059 *  - con->in_msg == NULL
2060 * or if we set *skip = 0:
2061 *  - con->in_msg is non-null.
2062 * On error (ENOMEM, EAGAIN, ...),
2063 *  - con->in_msg == NULL
2064 */
2065int ceph_con_in_msg_alloc(struct ceph_connection *con,
2066			  struct ceph_msg_header *hdr, int *skip)
2067{
2068	int middle_len = le32_to_cpu(hdr->middle_len);
2069	struct ceph_msg *msg;
2070	int ret = 0;
2071
2072	BUG_ON(con->in_msg != NULL);
2073	BUG_ON(!con->ops->alloc_msg);
2074
2075	mutex_unlock(&con->mutex);
2076	msg = con->ops->alloc_msg(con, hdr, skip);
2077	mutex_lock(&con->mutex);
2078	if (con->state != CEPH_CON_S_OPEN) {
2079		if (msg)
2080			ceph_msg_put(msg);
2081		return -EAGAIN;
2082	}
2083	if (msg) {
2084		BUG_ON(*skip);
2085		msg_con_set(msg, con);
2086		con->in_msg = msg;
2087	} else {
2088		/*
2089		 * Null message pointer means either we should skip
2090		 * this message or we couldn't allocate memory.  The
2091		 * former is not an error.
2092		 */
2093		if (*skip)
2094			return 0;
2095
2096		con->error_msg = "error allocating memory for incoming message";
2097		return -ENOMEM;
2098	}
2099	memcpy(&con->in_msg->hdr, hdr, sizeof(*hdr));
2100
2101	if (middle_len && !con->in_msg->middle) {
2102		ret = ceph_alloc_middle(con, con->in_msg);
2103		if (ret < 0) {
2104			ceph_msg_put(con->in_msg);
2105			con->in_msg = NULL;
2106		}
2107	}
2108
2109	return ret;
2110}
2111
2112void ceph_con_get_out_msg(struct ceph_connection *con)
2113{
2114	struct ceph_msg *msg;
2115
2116	BUG_ON(list_empty(&con->out_queue));
2117	msg = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
2118	WARN_ON(msg->con != con);
2119
2120	/*
2121	 * Put the message on "sent" list using a ref from ceph_con_send().
2122	 * It is put when the message is acked or revoked.
2123	 */
2124	list_move_tail(&msg->list_head, &con->out_sent);
2125
2126	/*
2127	 * Only assign outgoing seq # if we haven't sent this message
2128	 * yet.  If it is requeued, resend with it's original seq.
2129	 */
2130	if (msg->needs_out_seq) {
2131		msg->hdr.seq = cpu_to_le64(++con->out_seq);
2132		msg->needs_out_seq = false;
2133
2134		if (con->ops->reencode_message)
2135			con->ops->reencode_message(msg);
2136	}
2137
2138	/*
2139	 * Get a ref for out_msg.  It is put when we are done sending the
2140	 * message or in case of a fault.
2141	 */
2142	WARN_ON(con->out_msg);
2143	con->out_msg = ceph_msg_get(msg);
2144}
2145
2146/*
2147 * Free a generically kmalloc'd message.
2148 */
2149static void ceph_msg_free(struct ceph_msg *m)
2150{
2151	dout("%s %p\n", __func__, m);
2152	kvfree(m->front.iov_base);
2153	kfree(m->data);
2154	kmem_cache_free(ceph_msg_cache, m);
2155}
2156
2157static void ceph_msg_release(struct kref *kref)
2158{
2159	struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
2160	int i;
2161
2162	dout("%s %p\n", __func__, m);
2163	WARN_ON(!list_empty(&m->list_head));
2164
2165	msg_con_set(m, NULL);
2166
2167	/* drop middle, data, if any */
2168	if (m->middle) {
2169		ceph_buffer_put(m->middle);
2170		m->middle = NULL;
2171	}
2172
2173	for (i = 0; i < m->num_data_items; i++)
2174		ceph_msg_data_destroy(&m->data[i]);
2175
2176	if (m->pool)
2177		ceph_msgpool_put(m->pool, m);
2178	else
2179		ceph_msg_free(m);
2180}
2181
2182struct ceph_msg *ceph_msg_get(struct ceph_msg *msg)
2183{
2184	dout("%s %p (was %d)\n", __func__, msg,
2185	     kref_read(&msg->kref));
2186	kref_get(&msg->kref);
2187	return msg;
2188}
2189EXPORT_SYMBOL(ceph_msg_get);
2190
2191void ceph_msg_put(struct ceph_msg *msg)
2192{
2193	dout("%s %p (was %d)\n", __func__, msg,
2194	     kref_read(&msg->kref));
2195	kref_put(&msg->kref, ceph_msg_release);
2196}
2197EXPORT_SYMBOL(ceph_msg_put);
2198
2199void ceph_msg_dump(struct ceph_msg *msg)
2200{
2201	pr_debug("msg_dump %p (front_alloc_len %d length %zd)\n", msg,
2202		 msg->front_alloc_len, msg->data_length);
2203	print_hex_dump(KERN_DEBUG, "header: ",
2204		       DUMP_PREFIX_OFFSET, 16, 1,
2205		       &msg->hdr, sizeof(msg->hdr), true);
2206	print_hex_dump(KERN_DEBUG, " front: ",
2207		       DUMP_PREFIX_OFFSET, 16, 1,
2208		       msg->front.iov_base, msg->front.iov_len, true);
2209	if (msg->middle)
2210		print_hex_dump(KERN_DEBUG, "middle: ",
2211			       DUMP_PREFIX_OFFSET, 16, 1,
2212			       msg->middle->vec.iov_base,
2213			       msg->middle->vec.iov_len, true);
2214	print_hex_dump(KERN_DEBUG, "footer: ",
2215		       DUMP_PREFIX_OFFSET, 16, 1,
2216		       &msg->footer, sizeof(msg->footer), true);
2217}
2218EXPORT_SYMBOL(ceph_msg_dump);