net/ceph/messenger.c

   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 #include <linux/bio.h>
  13 #include <linux/blkdev.h>
  14 #include <net/tcp.h>
  15
  16 #include <linux/ceph/libceph.h>
  17 #include <linux/ceph/messenger.h>
  18 #include <linux/ceph/decode.h>
  19 #include <linux/ceph/pagelist.h>
  20
  21 /*
  22  * Ceph uses the messenger to exchange ceph_msg messages with other
  23  * hosts in the system.  The messenger provides ordered and reliable
  24  * delivery.  We tolerate TCP disconnects by reconnecting (with
  25  * exponential backoff) in the case of a fault (disconnection, bad
  26  * crc, protocol error).  Acks allow sent messages to be discarded by
  27  * the sender.
  28  */
  29
  30 /* static tag bytes (protocol control messages) */
  31 static char tag_msg = CEPH_MSGR_TAG_MSG;
  32 static char tag_ack = CEPH_MSGR_TAG_ACK;
  33 static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
  34
  35 #ifdef CONFIG_LOCKDEP
  36 static struct lock_class_key socket_class;
  37 #endif
  38
  39
  40 static void queue_con(struct ceph_connection *con);
  41 static void con_work(struct work_struct *);
  42 static void ceph_fault(struct ceph_connection *con);
  43
  44 /*
  45  * nicely render a sockaddr as a string.
  46  */
  47 #define MAX_ADDR_STR 20
  48 #define MAX_ADDR_STR_LEN 60
  49 static char addr_str[MAX_ADDR_STR][MAX_ADDR_STR_LEN];
  50 static DEFINE_SPINLOCK(addr_str_lock);
  51 static int last_addr_str;
  52
  53 const char *ceph_pr_addr(const struct sockaddr_storage *ss)
  54 {
  55         int i;
  56         char *s;
  57         struct sockaddr_in *in4 = (void *)ss;
  58         struct sockaddr_in6 *in6 = (void *)ss;
  59
  60         spin_lock(&addr_str_lock);
  61         i = last_addr_str++;
  62         if (last_addr_str == MAX_ADDR_STR)
  63                 last_addr_str = 0;
  64         spin_unlock(&addr_str_lock);
  65         s = addr_str[i];
  66
  67         switch (ss->ss_family) {
  68         case AF_INET:
  69                 snprintf(s, MAX_ADDR_STR_LEN, "%pI4:%u", &in4->sin_addr,
  70                          (unsigned int)ntohs(in4->sin_port));
  71                 break;
  72
  73         case AF_INET6:
  74                 snprintf(s, MAX_ADDR_STR_LEN, "[%pI6c]:%u", &in6->sin6_addr,
  75                          (unsigned int)ntohs(in6->sin6_port));
  76                 break;
  77
  78         default:
  79                 sprintf(s, "(unknown sockaddr family %d)", (int)ss->ss_family);
  80         }
  81
  82         return s;
  83 }
  84 EXPORT_SYMBOL(ceph_pr_addr);
  85
  86 static void encode_my_addr(struct ceph_messenger *msgr)
  87 {
  88         memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
  89         ceph_encode_addr(&msgr->my_enc_addr);
  90 }
  91
  92 /*
  93  * work queue for all reading and writing to/from the socket.
  94  */
  95 struct workqueue_struct *ceph_msgr_wq;
  96
  97 int ceph_msgr_init(void)
  98 {
  99         ceph_msgr_wq = create_workqueue("ceph-msgr");
 100         if (IS_ERR(ceph_msgr_wq)) {
 101                 int ret = PTR_ERR(ceph_msgr_wq);
 102                 pr_err("msgr_init failed to create workqueue: %d\n", ret);
 103                 ceph_msgr_wq = NULL;
 104                 return ret;
 105         }
 106         return 0;
 107 }
 108 EXPORT_SYMBOL(ceph_msgr_init);
 109
 110 void ceph_msgr_exit(void)
 111 {
 112         destroy_workqueue(ceph_msgr_wq);
 113 }
 114 EXPORT_SYMBOL(ceph_msgr_exit);
 115
 116 void ceph_msgr_flush(void)
 117 {
 118         flush_workqueue(ceph_msgr_wq);
 119 }
 120 EXPORT_SYMBOL(ceph_msgr_flush);
 121
 122
 123 /*
 124  * socket callback functions
 125  */
 126
 127 /* data available on socket, or listen socket received a connect */
 128 static void ceph_data_ready(struct sock *sk, int count_unused)
 129 {
 130         struct ceph_connection *con =
 131                 (struct ceph_connection *)sk->sk_user_data;
 132         if (sk->sk_state != TCP_CLOSE_WAIT) {
 133                 dout("ceph_data_ready on %p state = %lu, queueing work\n",
 134                      con, con->state);
 135                 queue_con(con);
 136         }
 137 }
 138
 139 /* socket has buffer space for writing */
 140 static void ceph_write_space(struct sock *sk)
 141 {
 142         struct ceph_connection *con =
 143                 (struct ceph_connection *)sk->sk_user_data;
 144
 145         /* only queue to workqueue if there is data we want to write. */
 146         if (test_bit(WRITE_PENDING, &con->state)) {
 147                 dout("ceph_write_space %p queueing write work\n", con);
 148                 queue_con(con);
 149         } else {
 150                 dout("ceph_write_space %p nothing to write\n", con);
 151         }
 152
 153         /* since we have our own write_space, clear the SOCK_NOSPACE flag */
 154         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 155 }
 156
 157 /* socket's state has changed */
 158 static void ceph_state_change(struct sock *sk)
 159 {
 160         struct ceph_connection *con =
 161                 (struct ceph_connection *)sk->sk_user_data;
 162
 163         dout("ceph_state_change %p state = %lu sk_state = %u\n",
 164              con, con->state, sk->sk_state);
 165
 166         if (test_bit(CLOSED, &con->state))
 167                 return;
 168
 169         switch (sk->sk_state) {
 170         case TCP_CLOSE:
 171                 dout("ceph_state_change TCP_CLOSE\n");
 172         case TCP_CLOSE_WAIT:
 173                 dout("ceph_state_change TCP_CLOSE_WAIT\n");
 174                 if (test_and_set_bit(SOCK_CLOSED, &con->state) == 0) {
 175                         if (test_bit(CONNECTING, &con->state))
 176                                 con->error_msg = "connection failed";
 177                         else
 178                                 con->error_msg = "socket closed";
 179                         queue_con(con);
 180                 }
 181                 break;
 182         case TCP_ESTABLISHED:
 183                 dout("ceph_state_change TCP_ESTABLISHED\n");
 184                 queue_con(con);
 185                 break;
 186         }
 187 }
 188
 189 /*
 190  * set up socket callbacks
 191  */
 192 static void set_sock_callbacks(struct socket *sock,
 193                                struct ceph_connection *con)
 194 {
 195         struct sock *sk = sock->sk;
 196         sk->sk_user_data = (void *)con;
 197         sk->sk_data_ready = ceph_data_ready;
 198         sk->sk_write_space = ceph_write_space;
 199         sk->sk_state_change = ceph_state_change;
 200 }
 201
 202
 203 /*
 204  * socket helpers
 205  */
 206
 207 /*
 208  * initiate connection to a remote socket.
 209  */
 210 static struct socket *ceph_tcp_connect(struct ceph_connection *con)
 211 {
 212         struct sockaddr_storage *paddr = &con->peer_addr.in_addr;
 213         struct socket *sock;
 214         int ret;
 215
 216         BUG_ON(con->sock);
 217         ret = sock_create_kern(con->peer_addr.in_addr.ss_family, SOCK_STREAM,
 218                                IPPROTO_TCP, &sock);
 219         if (ret)
 220                 return ERR_PTR(ret);
 221         con->sock = sock;
 222         sock->sk->sk_allocation = GFP_NOFS;
 223
 224 #ifdef CONFIG_LOCKDEP
 225         lockdep_set_class(&sock->sk->sk_lock, &socket_class);
 226 #endif
 227
 228         set_sock_callbacks(sock, con);
 229
 230         dout("connect %s\n", ceph_pr_addr(&con->peer_addr.in_addr));
 231
 232         ret = sock->ops->connect(sock, (struct sockaddr *)paddr, sizeof(*paddr),
 233                                  O_NONBLOCK);
 234         if (ret == -EINPROGRESS) {
 235                 dout("connect %s EINPROGRESS sk_state = %u\n",
 236                      ceph_pr_addr(&con->peer_addr.in_addr),
 237                      sock->sk->sk_state);
 238                 ret = 0;
 239         }
 240         if (ret < 0) {
 241                 pr_err("connect %s error %d\n",
 242                        ceph_pr_addr(&con->peer_addr.in_addr), ret);
 243                 sock_release(sock);
 244                 con->sock = NULL;
 245                 con->error_msg = "connect error";
 246         }
 247
 248         if (ret < 0)
 249                 return ERR_PTR(ret);
 250         return sock;
 251 }
 252
 253 static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
 254 {
 255         struct kvec iov = {buf, len};
 256         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 257
 258         return kernel_recvmsg(sock, &msg, &iov, 1, len, msg.msg_flags);
 259 }
 260
 261 /*
 262  * write something.  @more is true if caller will be sending more data
 263  * shortly.
 264  */
 265 static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
 266                      size_t kvlen, size_t len, int more)
 267 {
 268         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 269
 270         if (more)
 271                 msg.msg_flags |= MSG_MORE;
 272         else
 273                 msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
 274
 275         return kernel_sendmsg(sock, &msg, iov, kvlen, len);
 276 }
 277
 278
 279 /*
 280  * Shutdown/close the socket for the given connection.
 281  */
 282 static int con_close_socket(struct ceph_connection *con)
 283 {
 284         int rc;
 285
 286         dout("con_close_socket on %p sock %p\n", con, con->sock);
 287         if (!con->sock)
 288                 return 0;
 289         set_bit(SOCK_CLOSED, &con->state);
 290         rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
 291         sock_release(con->sock);
 292         con->sock = NULL;
 293         clear_bit(SOCK_CLOSED, &con->state);
 294         return rc;
 295 }
 296
 297 /*
 298  * Reset a connection.  Discard all incoming and outgoing messages
 299  * and clear *_seq state.
 300  */
 301 static void ceph_msg_remove(struct ceph_msg *msg)
 302 {
 303         list_del_init(&msg->list_head);
 304         ceph_msg_put(msg);
 305 }
 306 static void ceph_msg_remove_list(struct list_head *head)
 307 {
 308         while (!list_empty(head)) {
 309                 struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
 310                                                         list_head);
 311                 ceph_msg_remove(msg);
 312         }
 313 }
 314
 315 static void reset_connection(struct ceph_connection *con)
 316 {
 317         /* reset connection, out_queue, msg_ and connect_seq */
 318         /* discard existing out_queue and msg_seq */
 319         ceph_msg_remove_list(&con->out_queue);
 320         ceph_msg_remove_list(&con->out_sent);
 321
 322         if (con->in_msg) {
 323                 ceph_msg_put(con->in_msg);
 324                 con->in_msg = NULL;
 325         }
 326
 327         con->connect_seq = 0;
 328         con->out_seq = 0;
 329         if (con->out_msg) {
 330                 ceph_msg_put(con->out_msg);
 331                 con->out_msg = NULL;
 332         }
 333         con->out_keepalive_pending = false;
 334         con->in_seq = 0;
 335         con->in_seq_acked = 0;
 336 }
 337
 338 /*
 339  * mark a peer down.  drop any open connections.
 340  */
 341 void ceph_con_close(struct ceph_connection *con)
 342 {
 343         dout("con_close %p peer %s\n", con,
 344              ceph_pr_addr(&con->peer_addr.in_addr));
 345         set_bit(CLOSED, &con->state);  /* in case there's queued work */
 346         clear_bit(STANDBY, &con->state);  /* avoid connect_seq bump */
 347         clear_bit(LOSSYTX, &con->state);  /* so we retry next connect */
 348         clear_bit(KEEPALIVE_PENDING, &con->state);
 349         clear_bit(WRITE_PENDING, &con->state);
 350         mutex_lock(&con->mutex);
 351         reset_connection(con);
 352         con->peer_global_seq = 0;
 353         cancel_delayed_work(&con->work);
 354         mutex_unlock(&con->mutex);
 355         queue_con(con);
 356 }
 357 EXPORT_SYMBOL(ceph_con_close);
 358
 359 /*
 360  * Reopen a closed connection, with a new peer address.
 361  */
 362 void ceph_con_open(struct ceph_connection *con, struct ceph_entity_addr *addr)
 363 {
 364         dout("con_open %p %s\n", con, ceph_pr_addr(&addr->in_addr));
 365         set_bit(OPENING, &con->state);
 366         clear_bit(CLOSED, &con->state);
 367         memcpy(&con->peer_addr, addr, sizeof(*addr));
 368         con->delay = 0;      /* reset backoff memory */
 369         queue_con(con);
 370 }
 371 EXPORT_SYMBOL(ceph_con_open);
 372
 373 /*
 374  * return true if this connection ever successfully opened
 375  */
 376 bool ceph_con_opened(struct ceph_connection *con)
 377 {
 378         return con->connect_seq > 0;
 379 }
 380
 381 /*
 382  * generic get/put
 383  */
 384 struct ceph_connection *ceph_con_get(struct ceph_connection *con)
 385 {
 386         dout("con_get %p nref = %d -> %d\n", con,
 387              atomic_read(&con->nref), atomic_read(&con->nref) + 1);
 388         if (atomic_inc_not_zero(&con->nref))
 389                 return con;
 390         return NULL;
 391 }
 392
 393 void ceph_con_put(struct ceph_connection *con)
 394 {
 395         dout("con_put %p nref = %d -> %d\n", con,
 396              atomic_read(&con->nref), atomic_read(&con->nref) - 1);
 397         BUG_ON(atomic_read(&con->nref) == 0);
 398         if (atomic_dec_and_test(&con->nref)) {
 399                 BUG_ON(con->sock);
 400                 kfree(con);
 401         }
 402 }
 403
 404 /*
 405  * initialize a new connection.
 406  */
 407 void ceph_con_init(struct ceph_messenger *msgr, struct ceph_connection *con)
 408 {
 409         dout("con_init %p\n", con);
 410         memset(con, 0, sizeof(*con));
 411         atomic_set(&con->nref, 1);
 412         con->msgr = msgr;
 413         mutex_init(&con->mutex);
 414         INIT_LIST_HEAD(&con->out_queue);
 415         INIT_LIST_HEAD(&con->out_sent);
 416         INIT_DELAYED_WORK(&con->work, con_work);
 417 }
 418 EXPORT_SYMBOL(ceph_con_init);
 419
 420
 421 /*
 422  * We maintain a global counter to order connection attempts.  Get
 423  * a unique seq greater than @gt.
 424  */
 425 static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
 426 {
 427         u32 ret;
 428
 429         spin_lock(&msgr->global_seq_lock);
 430         if (msgr->global_seq < gt)
 431                 msgr->global_seq = gt;
 432         ret = ++msgr->global_seq;
 433         spin_unlock(&msgr->global_seq_lock);
 434         return ret;
 435 }
 436
 437
 438 /*
 439  * Prepare footer for currently outgoing message, and finish things
 440  * off.  Assumes out_kvec* are already valid.. we just add on to the end.
 441  */
 442 static void prepare_write_message_footer(struct ceph_connection *con, int v)
 443 {
 444         struct ceph_msg *m = con->out_msg;
 445
 446         dout("prepare_write_message_footer %p\n", con);
 447         con->out_kvec_is_msg = true;
 448         con->out_kvec[v].iov_base = &m->footer;
 449         con->out_kvec[v].iov_len = sizeof(m->footer);
 450         con->out_kvec_bytes += sizeof(m->footer);
 451         con->out_kvec_left++;
 452         con->out_more = m->more_to_follow;
 453         con->out_msg_done = true;
 454 }
 455
 456 /*
 457  * Prepare headers for the next outgoing message.
 458  */
 459 static void prepare_write_message(struct ceph_connection *con)
 460 {
 461         struct ceph_msg *m;
 462         int v = 0;
 463
 464         con->out_kvec_bytes = 0;
 465         con->out_kvec_is_msg = true;
 466         con->out_msg_done = false;
 467
 468         /* Sneak an ack in there first?  If we can get it into the same
 469          * TCP packet that's a good thing. */
 470         if (con->in_seq > con->in_seq_acked) {
 471                 con->in_seq_acked = con->in_seq;
 472                 con->out_kvec[v].iov_base = &tag_ack;
 473                 con->out_kvec[v++].iov_len = 1;
 474                 con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
 475                 con->out_kvec[v].iov_base = &con->out_temp_ack;
 476                 con->out_kvec[v++].iov_len = sizeof(con->out_temp_ack);
 477                 con->out_kvec_bytes = 1 + sizeof(con->out_temp_ack);
 478         }
 479
 480         m = list_first_entry(&con->out_queue,
 481                        struct ceph_msg, list_head);
 482         con->out_msg = m;
 483         if (test_bit(LOSSYTX, &con->state)) {
 484                 list_del_init(&m->list_head);
 485         } else {
 486                 /* put message on sent list */
 487                 ceph_msg_get(m);
 488                 list_move_tail(&m->list_head, &con->out_sent);
 489         }
 490
 491         /*
 492          * only assign outgoing seq # if we haven't sent this message
 493          * yet.  if it is requeued, resend with it's original seq.
 494          */
 495         if (m->needs_out_seq) {
 496                 m->hdr.seq = cpu_to_le64(++con->out_seq);
 497                 m->needs_out_seq = false;
 498         }
 499
 500         dout("prepare_write_message %p seq %lld type %d len %d+%d+%d %d pgs\n",
 501              m, con->out_seq, le16_to_cpu(m->hdr.type),
 502              le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
 503              le32_to_cpu(m->hdr.data_len),
 504              m->nr_pages);
 505         BUG_ON(le32_to_cpu(m->hdr.front_len) != m->front.iov_len);
 506
 507         /* tag + hdr + front + middle */
 508         con->out_kvec[v].iov_base = &tag_msg;
 509         con->out_kvec[v++].iov_len = 1;
 510         con->out_kvec[v].iov_base = &m->hdr;
 511         con->out_kvec[v++].iov_len = sizeof(m->hdr);
 512         con->out_kvec[v++] = m->front;
 513         if (m->middle)
 514                 con->out_kvec[v++] = m->middle->vec;
 515         con->out_kvec_left = v;
 516         con->out_kvec_bytes += 1 + sizeof(m->hdr) + m->front.iov_len +
 517                 (m->middle ? m->middle->vec.iov_len : 0);
 518         con->out_kvec_cur = con->out_kvec;
 519
 520         /* fill in crc (except data pages), footer */
 521         con->out_msg->hdr.crc =
 522                 cpu_to_le32(crc32c(0, (void *)&m->hdr,
 523                                       sizeof(m->hdr) - sizeof(m->hdr.crc)));
 524         con->out_msg->footer.flags = CEPH_MSG_FOOTER_COMPLETE;
 525         con->out_msg->footer.front_crc =
 526                 cpu_to_le32(crc32c(0, m->front.iov_base, m->front.iov_len));
 527         if (m->middle)
 528                 con->out_msg->footer.middle_crc =
 529                         cpu_to_le32(crc32c(0, m->middle->vec.iov_base,
 530                                            m->middle->vec.iov_len));
 531         else
 532                 con->out_msg->footer.middle_crc = 0;
 533         con->out_msg->footer.data_crc = 0;
 534         dout("prepare_write_message front_crc %u data_crc %u\n",
 535              le32_to_cpu(con->out_msg->footer.front_crc),
 536              le32_to_cpu(con->out_msg->footer.middle_crc));
 537
 538         /* is there a data payload? */
 539         if (le32_to_cpu(m->hdr.data_len) > 0) {
 540                 /* initialize page iterator */
 541                 con->out_msg_pos.page = 0;
 542                 if (m->pages)
 543                         con->out_msg_pos.page_pos =
 544                                 le16_to_cpu(m->hdr.data_off) & ~PAGE_MASK;
 545                 else
 546                         con->out_msg_pos.page_pos = 0;
 547                 con->out_msg_pos.data_pos = 0;
 548                 con->out_msg_pos.did_page_crc = 0;
 549                 con->out_more = 1;  /* data + footer will follow */
 550         } else {
 551                 /* no, queue up footer too and be done */
 552                 prepare_write_message_footer(con, v);
 553         }
 554
 555         set_bit(WRITE_PENDING, &con->state);
 556 }
 557
 558 /*
 559  * Prepare an ack.
 560  */
 561 static void prepare_write_ack(struct ceph_connection *con)
 562 {
 563         dout("prepare_write_ack %p %llu -> %llu\n", con,
 564              con->in_seq_acked, con->in_seq);
 565         con->in_seq_acked = con->in_seq;
 566
 567         con->out_kvec[0].iov_base = &tag_ack;
 568         con->out_kvec[0].iov_len = 1;
 569         con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
 570         con->out_kvec[1].iov_base = &con->out_temp_ack;
 571         con->out_kvec[1].iov_len = sizeof(con->out_temp_ack);
 572         con->out_kvec_left = 2;
 573         con->out_kvec_bytes = 1 + sizeof(con->out_temp_ack);
 574         con->out_kvec_cur = con->out_kvec;
 575         con->out_more = 1;  /* more will follow.. eventually.. */
 576         set_bit(WRITE_PENDING, &con->state);
 577 }
 578
 579 /*
 580  * Prepare to write keepalive byte.
 581  */
 582 static void prepare_write_keepalive(struct ceph_connection *con)
 583 {
 584         dout("prepare_write_keepalive %p\n", con);
 585         con->out_kvec[0].iov_base = &tag_keepalive;
 586         con->out_kvec[0].iov_len = 1;
 587         con->out_kvec_left = 1;
 588         con->out_kvec_bytes = 1;
 589         con->out_kvec_cur = con->out_kvec;
 590         set_bit(WRITE_PENDING, &con->state);
 591 }
 592
 593 /*
 594  * Connection negotiation.
 595  */
 596
 597 static void prepare_connect_authorizer(struct ceph_connection *con)
 598 {
 599         void *auth_buf;
 600         int auth_len = 0;
 601         int auth_protocol = 0;
 602
 603         mutex_unlock(&con->mutex);
 604         if (con->ops->get_authorizer)
 605                 con->ops->get_authorizer(con, &auth_buf, &auth_len,
 606                                          &auth_protocol, &con->auth_reply_buf,
 607                                          &con->auth_reply_buf_len,
 608                                          con->auth_retry);
 609         mutex_lock(&con->mutex);
 610
 611         con->out_connect.authorizer_protocol = cpu_to_le32(auth_protocol);
 612         con->out_connect.authorizer_len = cpu_to_le32(auth_len);
 613
 614         con->out_kvec[con->out_kvec_left].iov_base = auth_buf;
 615         con->out_kvec[con->out_kvec_left].iov_len = auth_len;
 616         con->out_kvec_left++;
 617         con->out_kvec_bytes += auth_len;
 618 }
 619
 620 /*
 621  * We connected to a peer and are saying hello.
 622  */
 623 static void prepare_write_banner(struct ceph_messenger *msgr,
 624                                  struct ceph_connection *con)
 625 {
 626         int len = strlen(CEPH_BANNER);
 627
 628         con->out_kvec[0].iov_base = CEPH_BANNER;
 629         con->out_kvec[0].iov_len = len;
 630         con->out_kvec[1].iov_base = &msgr->my_enc_addr;
 631         con->out_kvec[1].iov_len = sizeof(msgr->my_enc_addr);
 632         con->out_kvec_left = 2;
 633         con->out_kvec_bytes = len + sizeof(msgr->my_enc_addr);
 634         con->out_kvec_cur = con->out_kvec;
 635         con->out_more = 0;
 636         set_bit(WRITE_PENDING, &con->state);
 637 }
 638
 639 static void prepare_write_connect(struct ceph_messenger *msgr,
 640                                   struct ceph_connection *con,
 641                                   int after_banner)
 642 {
 643         unsigned global_seq = get_global_seq(con->msgr, 0);
 644         int proto;
 645
 646         switch (con->peer_name.type) {
 647         case CEPH_ENTITY_TYPE_MON:
 648                 proto = CEPH_MONC_PROTOCOL;
 649                 break;
 650         case CEPH_ENTITY_TYPE_OSD:
 651                 proto = CEPH_OSDC_PROTOCOL;
 652                 break;
 653         case CEPH_ENTITY_TYPE_MDS:
 654                 proto = CEPH_MDSC_PROTOCOL;
 655                 break;
 656         default:
 657                 BUG();
 658         }
 659
 660         dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
 661              con->connect_seq, global_seq, proto);
 662
 663         con->out_connect.features = cpu_to_le64(msgr->supported_features);
 664         con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
 665         con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
 666         con->out_connect.global_seq = cpu_to_le32(global_seq);
 667         con->out_connect.protocol_version = cpu_to_le32(proto);
 668         con->out_connect.flags = 0;
 669
 670         if (!after_banner) {
 671                 con->out_kvec_left = 0;
 672                 con->out_kvec_bytes = 0;
 673         }
 674         con->out_kvec[con->out_kvec_left].iov_base = &con->out_connect;
 675         con->out_kvec[con->out_kvec_left].iov_len = sizeof(con->out_connect);
 676         con->out_kvec_left++;
 677         con->out_kvec_bytes += sizeof(con->out_connect);
 678         con->out_kvec_cur = con->out_kvec;
 679         con->out_more = 0;
 680         set_bit(WRITE_PENDING, &con->state);
 681
 682         prepare_connect_authorizer(con);
 683 }
 684
 685
 686 /*
 687  * write as much of pending kvecs to the socket as we can.
 688  *  1 -> done
 689  *  0 -> socket full, but more to do
 690  * <0 -> error
 691  */
 692 static int write_partial_kvec(struct ceph_connection *con)
 693 {
 694         int ret;
 695
 696         dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
 697         while (con->out_kvec_bytes > 0) {
 698                 ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
 699                                        con->out_kvec_left, con->out_kvec_bytes,
 700                                        con->out_more);
 701                 if (ret <= 0)
 702                         goto out;
 703                 con->out_kvec_bytes -= ret;
 704                 if (con->out_kvec_bytes == 0)
 705                         break;            /* done */
 706                 while (ret > 0) {
 707                         if (ret >= con->out_kvec_cur->iov_len) {
 708                                 ret -= con->out_kvec_cur->iov_len;
 709                                 con->out_kvec_cur++;
 710                                 con->out_kvec_left--;
 711                         } else {
 712                                 con->out_kvec_cur->iov_len -= ret;
 713                                 con->out_kvec_cur->iov_base += ret;
 714                                 ret = 0;
 715                                 break;
 716                         }
 717                 }
 718         }
 719         con->out_kvec_left = 0;
 720         con->out_kvec_is_msg = false;
 721         ret = 1;
 722 out:
 723         dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
 724              con->out_kvec_bytes, con->out_kvec_left, ret);
 725         return ret;  /* done! */
 726 }
 727
 728 #ifdef CONFIG_BLOCK
 729 static void init_bio_iter(struct bio *bio, struct bio **iter, int *seg)
 730 {
 731         if (!bio) {
 732                 *iter = NULL;
 733                 *seg = 0;
 734                 return;
 735         }
 736         *iter = bio;
 737         *seg = bio->bi_idx;
 738 }
 739
 740 static void iter_bio_next(struct bio **bio_iter, int *seg)
 741 {
 742         if (*bio_iter == NULL)
 743                 return;
 744
 745         BUG_ON(*seg >= (*bio_iter)->bi_vcnt);
 746
 747         (*seg)++;
 748         if (*seg == (*bio_iter)->bi_vcnt)
 749                 init_bio_iter((*bio_iter)->bi_next, bio_iter, seg);
 750 }
 751 #endif
 752
 753 /*
 754  * Write as much message data payload as we can.  If we finish, queue
 755  * up the footer.
 756  *  1 -> done, footer is now queued in out_kvec[].
 757  *  0 -> socket full, but more to do
 758  * <0 -> error
 759  */
 760 static int write_partial_msg_pages(struct ceph_connection *con)
 761 {
 762         struct ceph_msg *msg = con->out_msg;
 763         unsigned data_len = le32_to_cpu(msg->hdr.data_len);
 764         size_t len;
 765         int crc = con->msgr->nocrc;
 766         int ret;
 767         int total_max_write;
 768         int in_trail = 0;
 769         size_t trail_len = (msg->trail ? msg->trail->length : 0);
 770
 771         dout("write_partial_msg_pages %p msg %p page %d/%d offset %d\n",
 772              con, con->out_msg, con->out_msg_pos.page, con->out_msg->nr_pages,
 773              con->out_msg_pos.page_pos);
 774
 775 #ifdef CONFIG_BLOCK
 776         if (msg->bio && !msg->bio_iter)
 777                 init_bio_iter(msg->bio, &msg->bio_iter, &msg->bio_seg);
 778 #endif
 779
 780         while (data_len > con->out_msg_pos.data_pos) {
 781                 struct page *page = NULL;
 782                 void *kaddr = NULL;
 783                 int max_write = PAGE_SIZE;
 784                 int page_shift = 0;
 785
 786                 total_max_write = data_len - trail_len -
 787                         con->out_msg_pos.data_pos;
 788
 789                 /*
 790                  * if we are calculating the data crc (the default), we need
 791                  * to map the page.  if our pages[] has been revoked, use the
 792                  * zero page.
 793                  */
 794
 795                 /* have we reached the trail part of the data? */
 796                 if (con->out_msg_pos.data_pos >= data_len - trail_len) {
 797                         in_trail = 1;
 798
 799                         total_max_write = data_len - con->out_msg_pos.data_pos;
 800
 801                         page = list_first_entry(&msg->trail->head,
 802                                                 struct page, lru);
 803                         if (crc)
 804                                 kaddr = kmap(page);
 805                         max_write = PAGE_SIZE;
 806                 } else if (msg->pages) {
 807                         page = msg->pages[con->out_msg_pos.page];
 808                         if (crc)
 809                                 kaddr = kmap(page);
 810                 } else if (msg->pagelist) {
 811                         page = list_first_entry(&msg->pagelist->head,
 812                                                 struct page, lru);
 813                         if (crc)
 814                                 kaddr = kmap(page);
 815 #ifdef CONFIG_BLOCK
 816                 } else if (msg->bio) {
 817                         struct bio_vec *bv;
 818
 819                         bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg);
 820                         page = bv->bv_page;
 821                         page_shift = bv->bv_offset;
 822                         if (crc)
 823                                 kaddr = kmap(page) + page_shift;
 824                         max_write = bv->bv_len;
 825 #endif
 826                 } else {
 827                         page = con->msgr->zero_page;
 828                         if (crc)
 829                                 kaddr = page_address(con->msgr->zero_page);
 830                 }
 831                 len = min_t(int, max_write - con->out_msg_pos.page_pos,
 832                             total_max_write);
 833
 834                 if (crc && !con->out_msg_pos.did_page_crc) {
 835                         void *base = kaddr + con->out_msg_pos.page_pos;
 836                         u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc);
 837
 838                         BUG_ON(kaddr == NULL);
 839                         con->out_msg->footer.data_crc =
 840                                 cpu_to_le32(crc32c(tmpcrc, base, len));
 841                         con->out_msg_pos.did_page_crc = 1;
 842                 }
 843                 ret = kernel_sendpage(con->sock, page,
 844                                       con->out_msg_pos.page_pos + page_shift,
 845                                       len,
 846                                       MSG_DONTWAIT | MSG_NOSIGNAL |
 847                                       MSG_MORE);
 848
 849                 if (crc &&
 850                     (msg->pages || msg->pagelist || msg->bio || in_trail))
 851                         kunmap(page);
 852
 853                 if (ret <= 0)
 854                         goto out;
 855
 856                 con->out_msg_pos.data_pos += ret;
 857                 con->out_msg_pos.page_pos += ret;
 858                 if (ret == len) {
 859                         con->out_msg_pos.page_pos = 0;
 860                         con->out_msg_pos.page++;
 861                         con->out_msg_pos.did_page_crc = 0;
 862                         if (in_trail)
 863                                 list_move_tail(&page->lru,
 864                                                &msg->trail->head);
 865                         else if (msg->pagelist)
 866                                 list_move_tail(&page->lru,
 867                                                &msg->pagelist->head);
 868 #ifdef CONFIG_BLOCK
 869                         else if (msg->bio)
 870                                 iter_bio_next(&msg->bio_iter, &msg->bio_seg);
 871 #endif
 872                 }
 873         }
 874
 875         dout("write_partial_msg_pages %p msg %p done\n", con, msg);
 876
 877         /* prepare and queue up footer, too */
 878         if (!crc)
 879                 con->out_msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
 880         con->out_kvec_bytes = 0;
 881         con->out_kvec_left = 0;
 882         con->out_kvec_cur = con->out_kvec;
 883         prepare_write_message_footer(con, 0);
 884         ret = 1;
 885 out:
 886         return ret;
 887 }
 888
 889 /*
 890  * write some zeros
 891  */
 892 static int write_partial_skip(struct ceph_connection *con)
 893 {
 894         int ret;
 895
 896         while (con->out_skip > 0) {
 897                 struct kvec iov = {
 898                         .iov_base = page_address(con->msgr->zero_page),
 899                         .iov_len = min(con->out_skip, (int)PAGE_CACHE_SIZE)
 900                 };
 901
 902                 ret = ceph_tcp_sendmsg(con->sock, &iov, 1, iov.iov_len, 1);
 903                 if (ret <= 0)
 904                         goto out;
 905                 con->out_skip -= ret;
 906         }
 907         ret = 1;
 908 out:
 909         return ret;
 910 }
 911
 912 /*
 913  * Prepare to read connection handshake, or an ack.
 914  */
 915 static void prepare_read_banner(struct ceph_connection *con)
 916 {
 917         dout("prepare_read_banner %p\n", con);
 918         con->in_base_pos = 0;
 919 }
 920
 921 static void prepare_read_connect(struct ceph_connection *con)
 922 {
 923         dout("prepare_read_connect %p\n", con);
 924         con->in_base_pos = 0;
 925 }
 926
 927 static void prepare_read_ack(struct ceph_connection *con)
 928 {
 929         dout("prepare_read_ack %p\n", con);
 930         con->in_base_pos = 0;
 931 }
 932
 933 static void prepare_read_tag(struct ceph_connection *con)
 934 {
 935         dout("prepare_read_tag %p\n", con);
 936         con->in_base_pos = 0;
 937         con->in_tag = CEPH_MSGR_TAG_READY;
 938 }
 939
 940 /*
 941  * Prepare to read a message.
 942  */
 943 static int prepare_read_message(struct ceph_connection *con)
 944 {
 945         dout("prepare_read_message %p\n", con);
 946         BUG_ON(con->in_msg != NULL);
 947         con->in_base_pos = 0;
 948         con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
 949         return 0;
 950 }
 951
 952
 953 static int read_partial(struct ceph_connection *con,
 954                         int *to, int size, void *object)
 955 {
 956         *to += size;
 957         while (con->in_base_pos < *to) {
 958                 int left = *to - con->in_base_pos;
 959                 int have = size - left;
 960                 int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
 961                 if (ret <= 0)
 962                         return ret;
 963                 con->in_base_pos += ret;
 964         }
 965         return 1;
 966 }
 967
 968
 969 /*
 970  * Read all or part of the connect-side handshake on a new connection
 971  */
 972 static int read_partial_banner(struct ceph_connection *con)
 973 {
 974         int ret, to = 0;
 975
 976         dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
 977
 978         /* peer's banner */
 979         ret = read_partial(con, &to, strlen(CEPH_BANNER), con->in_banner);
 980         if (ret <= 0)
 981                 goto out;
 982         ret = read_partial(con, &to, sizeof(con->actual_peer_addr),
 983                            &con->actual_peer_addr);
 984         if (ret <= 0)
 985                 goto out;
 986         ret = read_partial(con, &to, sizeof(con->peer_addr_for_me),
 987                            &con->peer_addr_for_me);
 988         if (ret <= 0)
 989                 goto out;
 990 out:
 991         return ret;
 992 }
 993
 994 static int read_partial_connect(struct ceph_connection *con)
 995 {
 996         int ret, to = 0;
 997
 998         dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
 999
1000         ret = read_partial(con, &to, sizeof(con->in_reply), &con->in_reply);
1001         if (ret <= 0)
1002                 goto out;
1003         ret = read_partial(con, &to, le32_to_cpu(con->in_reply.authorizer_len),
1004                            con->auth_reply_buf);
1005         if (ret <= 0)
1006                 goto out;
1007
1008         dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
1009              con, (int)con->in_reply.tag,
1010              le32_to_cpu(con->in_reply.connect_seq),
1011              le32_to_cpu(con->in_reply.global_seq));
1012 out:
1013         return ret;
1014
1015 }
1016
1017 /*
1018  * Verify the hello banner looks okay.
1019  */
1020 static int verify_hello(struct ceph_connection *con)
1021 {
1022         if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
1023                 pr_err("connect to %s got bad banner\n",
1024                        ceph_pr_addr(&con->peer_addr.in_addr));
1025                 con->error_msg = "protocol error, bad banner";
1026                 return -1;
1027         }
1028         return 0;
1029 }
1030
1031 static bool addr_is_blank(struct sockaddr_storage *ss)
1032 {
1033         switch (ss->ss_family) {
1034         case AF_INET:
1035                 return ((struct sockaddr_in *)ss)->sin_addr.s_addr == 0;
1036         case AF_INET6:
1037                 return
1038                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[0] == 0 &&
1039                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[1] == 0 &&
1040                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[2] == 0 &&
1041                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[3] == 0;
1042         }
1043         return false;
1044 }
1045
1046 static int addr_port(struct sockaddr_storage *ss)
1047 {
1048         switch (ss->ss_family) {
1049         case AF_INET:
1050                 return ntohs(((struct sockaddr_in *)ss)->sin_port);
1051         case AF_INET6:
1052                 return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
1053         }
1054         return 0;
1055 }
1056
1057 static void addr_set_port(struct sockaddr_storage *ss, int p)
1058 {
1059         switch (ss->ss_family) {
1060         case AF_INET:
1061                 ((struct sockaddr_in *)ss)->sin_port = htons(p);
1062         case AF_INET6:
1063                 ((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
1064         }
1065 }
1066
1067 /*
1068  * Parse an ip[:port] list into an addr array.  Use the default
1069  * monitor port if a port isn't specified.
1070  */
1071 int ceph_parse_ips(const char *c, const char *end,
1072                    struct ceph_entity_addr *addr,
1073                    int max_count, int *count)
1074 {
1075         int i;
1076         const char *p = c;
1077
1078         dout("parse_ips on '%.*s'\n", (int)(end-c), c);
1079         for (i = 0; i < max_count; i++) {
1080                 const char *ipend;
1081                 struct sockaddr_storage *ss = &addr[i].in_addr;
1082                 struct sockaddr_in *in4 = (void *)ss;
1083                 struct sockaddr_in6 *in6 = (void *)ss;
1084                 int port;
1085                 char delim = ',';
1086
1087                 if (*p == '[') {
1088                         delim = ']';
1089                         p++;
1090                 }
1091
1092                 memset(ss, 0, sizeof(*ss));
1093                 if (in4_pton(p, end - p, (u8 *)&in4->sin_addr.s_addr,
1094                              delim, &ipend))
1095                         ss->ss_family = AF_INET;
1096                 else if (in6_pton(p, end - p, (u8 *)&in6->sin6_addr.s6_addr,
1097                                   delim, &ipend))
1098                         ss->ss_family = AF_INET6;
1099                 else
1100                         goto bad;
1101                 p = ipend;
1102
1103                 if (delim == ']') {
1104                         if (*p != ']') {
1105                                 dout("missing matching ']'\n");
1106                                 goto bad;
1107                         }
1108                         p++;
1109                 }
1110
1111                 /* port? */
1112                 if (p < end && *p == ':') {
1113                         port = 0;
1114                         p++;
1115                         while (p < end && *p >= '0' && *p <= '9') {
1116                                 port = (port * 10) + (*p - '0');
1117                                 p++;
1118                         }
1119                         if (port > 65535 || port == 0)
1120                                 goto bad;
1121                 } else {
1122                         port = CEPH_MON_PORT;
1123                 }
1124
1125                 addr_set_port(ss, port);
1126
1127                 dout("parse_ips got %s\n", ceph_pr_addr(ss));
1128
1129                 if (p == end)
1130                         break;
1131                 if (*p != ',')
1132                         goto bad;
1133                 p++;
1134         }
1135
1136         if (p != end)
1137                 goto bad;
1138
1139         if (count)
1140                 *count = i + 1;
1141         return 0;
1142
1143 bad:
1144         pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c);
1145         return -EINVAL;
1146 }
1147 EXPORT_SYMBOL(ceph_parse_ips);
1148
1149 static int process_banner(struct ceph_connection *con)
1150 {
1151         dout("process_banner on %p\n", con);
1152
1153         if (verify_hello(con) < 0)
1154                 return -1;
1155
1156         ceph_decode_addr(&con->actual_peer_addr);
1157         ceph_decode_addr(&con->peer_addr_for_me);
1158
1159         /*
1160          * Make sure the other end is who we wanted.  note that the other
1161          * end may not yet know their ip address, so if it's 0.0.0.0, give
1162          * them the benefit of the doubt.
1163          */
1164         if (memcmp(&con->peer_addr, &con->actual_peer_addr,
1165                    sizeof(con->peer_addr)) != 0 &&
1166             !(addr_is_blank(&con->actual_peer_addr.in_addr) &&
1167               con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
1168                 pr_warning("wrong peer, want %s/%d, got %s/%d\n",
1169                            ceph_pr_addr(&con->peer_addr.in_addr),
1170                            (int)le32_to_cpu(con->peer_addr.nonce),
1171                            ceph_pr_addr(&con->actual_peer_addr.in_addr),
1172                            (int)le32_to_cpu(con->actual_peer_addr.nonce));
1173                 con->error_msg = "wrong peer at address";
1174                 return -1;
1175         }
1176
1177         /*
1178          * did we learn our address?
1179          */
1180         if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
1181                 int port = addr_port(&con->msgr->inst.addr.in_addr);
1182
1183                 memcpy(&con->msgr->inst.addr.in_addr,
1184                        &con->peer_addr_for_me.in_addr,
1185                        sizeof(con->peer_addr_for_me.in_addr));
1186                 addr_set_port(&con->msgr->inst.addr.in_addr, port);
1187                 encode_my_addr(con->msgr);
1188                 dout("process_banner learned my addr is %s\n",
1189                      ceph_pr_addr(&con->msgr->inst.addr.in_addr));
1190         }
1191
1192         set_bit(NEGOTIATING, &con->state);
1193         prepare_read_connect(con);
1194         return 0;
1195 }
1196
1197 static void fail_protocol(struct ceph_connection *con)
1198 {
1199         reset_connection(con);
1200         set_bit(CLOSED, &con->state);  /* in case there's queued work */
1201
1202         mutex_unlock(&con->mutex);
1203         if (con->ops->bad_proto)
1204                 con->ops->bad_proto(con);
1205         mutex_lock(&con->mutex);
1206 }
1207
1208 static int process_connect(struct ceph_connection *con)
1209 {
1210         u64 sup_feat = con->msgr->supported_features;
1211         u64 req_feat = con->msgr->required_features;
1212         u64 server_feat = le64_to_cpu(con->in_reply.features);
1213
1214         dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
1215
1216         switch (con->in_reply.tag) {
1217         case CEPH_MSGR_TAG_FEATURES:
1218                 pr_err("%s%lld %s feature set mismatch,"
1219                        " my %llx < server's %llx, missing %llx\n",
1220                        ENTITY_NAME(con->peer_name),
1221                        ceph_pr_addr(&con->peer_addr.in_addr),
1222                        sup_feat, server_feat, server_feat & ~sup_feat);
1223                 con->error_msg = "missing required protocol features";
1224                 fail_protocol(con);
1225                 return -1;
1226
1227         case CEPH_MSGR_TAG_BADPROTOVER:
1228                 pr_err("%s%lld %s protocol version mismatch,"
1229                        " my %d != server's %d\n",
1230                        ENTITY_NAME(con->peer_name),
1231                        ceph_pr_addr(&con->peer_addr.in_addr),
1232                        le32_to_cpu(con->out_connect.protocol_version),
1233                        le32_to_cpu(con->in_reply.protocol_version));
1234                 con->error_msg = "protocol version mismatch";
1235                 fail_protocol(con);
1236                 return -1;
1237
1238         case CEPH_MSGR_TAG_BADAUTHORIZER:
1239                 con->auth_retry++;
1240                 dout("process_connect %p got BADAUTHORIZER attempt %d\n", con,
1241                      con->auth_retry);
1242                 if (con->auth_retry == 2) {
1243                         con->error_msg = "connect authorization failure";
1244                         reset_connection(con);
1245                         set_bit(CLOSED, &con->state);
1246                         return -1;
1247                 }
1248                 con->auth_retry = 1;
1249                 prepare_write_connect(con->msgr, con, 0);
1250                 prepare_read_connect(con);
1251                 break;
1252
1253         case CEPH_MSGR_TAG_RESETSESSION:
1254                 /*
1255                  * If we connected with a large connect_seq but the peer
1256                  * has no record of a session with us (no connection, or
1257                  * connect_seq == 0), they will send RESETSESION to indicate
1258                  * that they must have reset their session, and may have
1259                  * dropped messages.
1260                  */
1261                 dout("process_connect got RESET peer seq %u\n",
1262                      le32_to_cpu(con->in_connect.connect_seq));
1263                 pr_err("%s%lld %s connection reset\n",
1264                        ENTITY_NAME(con->peer_name),
1265                        ceph_pr_addr(&con->peer_addr.in_addr));
1266                 reset_connection(con);
1267                 prepare_write_connect(con->msgr, con, 0);
1268                 prepare_read_connect(con);
1269
1270                 /* Tell ceph about it. */
1271                 mutex_unlock(&con->mutex);
1272                 pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));
1273                 if (con->ops->peer_reset)
1274                         con->ops->peer_reset(con);
1275                 mutex_lock(&con->mutex);
1276                 break;
1277
1278         case CEPH_MSGR_TAG_RETRY_SESSION:
1279                 /*
1280                  * If we sent a smaller connect_seq than the peer has, try
1281                  * again with a larger value.
1282                  */
1283                 dout("process_connect got RETRY my seq = %u, peer_seq = %u\n",
1284                      le32_to_cpu(con->out_connect.connect_seq),
1285                      le32_to_cpu(con->in_connect.connect_seq));
1286                 con->connect_seq = le32_to_cpu(con->in_connect.connect_seq);
1287                 prepare_write_connect(con->msgr, con, 0);
1288                 prepare_read_connect(con);
1289                 break;
1290
1291         case CEPH_MSGR_TAG_RETRY_GLOBAL:
1292                 /*
1293                  * If we sent a smaller global_seq than the peer has, try
1294                  * again with a larger value.
1295                  */
1296                 dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
1297                      con->peer_global_seq,
1298                      le32_to_cpu(con->in_connect.global_seq));
1299                 get_global_seq(con->msgr,
1300                                le32_to_cpu(con->in_connect.global_seq));
1301                 prepare_write_connect(con->msgr, con, 0);
1302                 prepare_read_connect(con);
1303                 break;
1304
1305         case CEPH_MSGR_TAG_READY:
1306                 if (req_feat & ~server_feat) {
1307                         pr_err("%s%lld %s protocol feature mismatch,"
1308                                " my required %llx > server's %llx, need %llx\n",
1309                                ENTITY_NAME(con->peer_name),
1310                                ceph_pr_addr(&con->peer_addr.in_addr),
1311                                req_feat, server_feat, req_feat & ~server_feat);
1312                         con->error_msg = "missing required protocol features";
1313                         fail_protocol(con);
1314                         return -1;
1315                 }
1316                 clear_bit(CONNECTING, &con->state);
1317                 con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
1318                 con->connect_seq++;
1319                 con->peer_features = server_feat;
1320                 dout("process_connect got READY gseq %d cseq %d (%d)\n",
1321                      con->peer_global_seq,
1322                      le32_to_cpu(con->in_reply.connect_seq),
1323                      con->connect_seq);
1324                 WARN_ON(con->connect_seq !=
1325                         le32_to_cpu(con->in_reply.connect_seq));
1326
1327                 if (con->in_reply.flags & CEPH_MSG_CONNECT_LOSSY)
1328                         set_bit(LOSSYTX, &con->state);
1329
1330                 prepare_read_tag(con);
1331                 break;
1332
1333         case CEPH_MSGR_TAG_WAIT:
1334                 /*
1335                  * If there is a connection race (we are opening
1336                  * connections to each other), one of us may just have
1337                  * to WAIT.  This shouldn't happen if we are the
1338                  * client.
1339                  */
1340                 pr_err("process_connect peer connecting WAIT\n");
1341
1342         default:
1343                 pr_err("connect protocol error, will retry\n");
1344                 con->error_msg = "protocol error, garbage tag during connect";
1345                 return -1;
1346         }
1347         return 0;
1348 }
1349
1350
1351 /*
1352  * read (part of) an ack
1353  */
1354 static int read_partial_ack(struct ceph_connection *con)
1355 {
1356         int to = 0;
1357
1358         return read_partial(con, &to, sizeof(con->in_temp_ack),
1359                             &con->in_temp_ack);
1360 }
1361
1362
1363 /*
1364  * We can finally discard anything that's been acked.
1365  */
1366 static void process_ack(struct ceph_connection *con)
1367 {
1368         struct ceph_msg *m;
1369         u64 ack = le64_to_cpu(con->in_temp_ack);
1370         u64 seq;
1371
1372         while (!list_empty(&con->out_sent)) {
1373                 m = list_first_entry(&con->out_sent, struct ceph_msg,
1374                                      list_head);
1375                 seq = le64_to_cpu(m->hdr.seq);
1376                 if (seq > ack)
1377                         break;
1378                 dout("got ack for seq %llu type %d at %p\n", seq,
1379                      le16_to_cpu(m->hdr.type), m);
1380                 ceph_msg_remove(m);
1381         }
1382         prepare_read_tag(con);
1383 }
1384
1385
1386
1387
1388 static int read_partial_message_section(struct ceph_connection *con,
1389                                         struct kvec *section,
1390                                         unsigned int sec_len, u32 *crc)
1391 {
1392         int ret, left;
1393
1394         BUG_ON(!section);
1395
1396         while (section->iov_len < sec_len) {
1397                 BUG_ON(section->iov_base == NULL);
1398                 left = sec_len - section->iov_len;
1399                 ret = ceph_tcp_recvmsg(con->sock, (char *)section->iov_base +
1400                                        section->iov_len, left);
1401                 if (ret <= 0)
1402                         return ret;
1403                 section->iov_len += ret;
1404                 if (section->iov_len == sec_len)
1405                         *crc = crc32c(0, section->iov_base,
1406                                       section->iov_len);
1407         }
1408
1409         return 1;
1410 }
1411
1412 static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
1413                                 struct ceph_msg_header *hdr,
1414                                 int *skip);
1415
1416
1417 static int read_partial_message_pages(struct ceph_connection *con,
1418                                       struct page **pages,
1419                                       unsigned data_len, int datacrc)
1420 {
1421         void *p;
1422         int ret;
1423         int left;
1424
1425         left = min((int)(data_len - con->in_msg_pos.data_pos),
1426                    (int)(PAGE_SIZE - con->in_msg_pos.page_pos));
1427         /* (page) data */
1428         BUG_ON(pages == NULL);
1429         p = kmap(pages[con->in_msg_pos.page]);
1430         ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
1431                                left);
1432         if (ret > 0 && datacrc)
1433                 con->in_data_crc =
1434                         crc32c(con->in_data_crc,
1435                                   p + con->in_msg_pos.page_pos, ret);
1436         kunmap(pages[con->in_msg_pos.page]);
1437         if (ret <= 0)
1438                 return ret;
1439         con->in_msg_pos.data_pos += ret;
1440         con->in_msg_pos.page_pos += ret;
1441         if (con->in_msg_pos.page_pos == PAGE_SIZE) {
1442                 con->in_msg_pos.page_pos = 0;
1443                 con->in_msg_pos.page++;
1444         }
1445
1446         return ret;
1447 }
1448
1449 #ifdef CONFIG_BLOCK
1450 static int read_partial_message_bio(struct ceph_connection *con,
1451                                     struct bio **bio_iter, int *bio_seg,
1452                                     unsigned data_len, int datacrc)
1453 {
1454         struct bio_vec *bv = bio_iovec_idx(*bio_iter, *bio_seg);
1455         void *p;
1456         int ret, left;
1457
1458         if (IS_ERR(bv))
1459                 return PTR_ERR(bv);
1460
1461         left = min((int)(data_len - con->in_msg_pos.data_pos),
1462                    (int)(bv->bv_len - con->in_msg_pos.page_pos));
1463
1464         p = kmap(bv->bv_page) + bv->bv_offset;
1465
1466         ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
1467                                left);
1468         if (ret > 0 && datacrc)
1469                 con->in_data_crc =
1470                         crc32c(con->in_data_crc,
1471                                   p + con->in_msg_pos.page_pos, ret);
1472         kunmap(bv->bv_page);
1473         if (ret <= 0)
1474                 return ret;
1475         con->in_msg_pos.data_pos += ret;
1476         con->in_msg_pos.page_pos += ret;
1477         if (con->in_msg_pos.page_pos == bv->bv_len) {
1478                 con->in_msg_pos.page_pos = 0;
1479                 iter_bio_next(bio_iter, bio_seg);
1480         }
1481
1482         return ret;
1483 }
1484 #endif
1485
1486 /*
1487  * read (part of) a message.
1488  */
1489 static int read_partial_message(struct ceph_connection *con)
1490 {
1491         struct ceph_msg *m = con->in_msg;
1492         int ret;
1493         int to, left;
1494         unsigned front_len, middle_len, data_len, data_off;
1495         int datacrc = con->msgr->nocrc;
1496         int skip;
1497         u64 seq;
1498
1499         dout("read_partial_message con %p msg %p\n", con, m);
1500
1501         /* header */
1502         while (con->in_base_pos < sizeof(con->in_hdr)) {
1503                 left = sizeof(con->in_hdr) - con->in_base_pos;
1504                 ret = ceph_tcp_recvmsg(con->sock,
1505                                        (char *)&con->in_hdr + con->in_base_pos,
1506                                        left);
1507                 if (ret <= 0)
1508                         return ret;
1509                 con->in_base_pos += ret;
1510                 if (con->in_base_pos == sizeof(con->in_hdr)) {
1511                         u32 crc = crc32c(0, (void *)&con->in_hdr,
1512                                  sizeof(con->in_hdr) - sizeof(con->in_hdr.crc));
1513                         if (crc != le32_to_cpu(con->in_hdr.crc)) {
1514                                 pr_err("read_partial_message bad hdr "
1515                                        " crc %u != expected %u\n",
1516                                        crc, con->in_hdr.crc);
1517                                 return -EBADMSG;
1518                         }
1519                 }
1520         }
1521         front_len = le32_to_cpu(con->in_hdr.front_len);
1522         if (front_len > CEPH_MSG_MAX_FRONT_LEN)
1523                 return -EIO;
1524         middle_len = le32_to_cpu(con->in_hdr.middle_len);
1525         if (middle_len > CEPH_MSG_MAX_DATA_LEN)
1526                 return -EIO;
1527         data_len = le32_to_cpu(con->in_hdr.data_len);
1528         if (data_len > CEPH_MSG_MAX_DATA_LEN)
1529                 return -EIO;
1530         data_off = le16_to_cpu(con->in_hdr.data_off);
1531
1532         /* verify seq# */
1533         seq = le64_to_cpu(con->in_hdr.seq);
1534         if ((s64)seq - (s64)con->in_seq < 1) {
1535                 pr_info("skipping %s%lld %s seq %lld, expected %lld\n",
1536                         ENTITY_NAME(con->peer_name),
1537                         ceph_pr_addr(&con->peer_addr.in_addr),
1538                         seq, con->in_seq + 1);
1539                 con->in_base_pos = -front_len - middle_len - data_len -
1540                         sizeof(m->footer);
1541                 con->in_tag = CEPH_MSGR_TAG_READY;
1542                 con->in_seq++;
1543                 return 0;
1544         } else if ((s64)seq - (s64)con->in_seq > 1) {
1545                 pr_err("read_partial_message bad seq %lld expected %lld\n",
1546                        seq, con->in_seq + 1);
1547                 con->error_msg = "bad message sequence # for incoming message";
1548                 return -EBADMSG;
1549         }
1550
1551         /* allocate message? */
1552         if (!con->in_msg) {
1553                 dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
1554                      con->in_hdr.front_len, con->in_hdr.data_len);
1555                 skip = 0;
1556                 con->in_msg = ceph_alloc_msg(con, &con->in_hdr, &skip);
1557                 if (skip) {
1558                         /* skip this message */
1559                         dout("alloc_msg said skip message\n");
1560                         BUG_ON(con->in_msg);
1561                         con->in_base_pos = -front_len - middle_len - data_len -
1562                                 sizeof(m->footer);
1563                         con->in_tag = CEPH_MSGR_TAG_READY;
1564                         con->in_seq++;
1565                         return 0;
1566                 }
1567                 if (!con->in_msg) {
1568                         con->error_msg =
1569                                 "error allocating memory for incoming message";
1570                         return -ENOMEM;
1571                 }
1572                 m = con->in_msg;
1573                 m->front.iov_len = 0;    /* haven't read it yet */
1574                 if (m->middle)
1575                         m->middle->vec.iov_len = 0;
1576
1577                 con->in_msg_pos.page = 0;
1578                 if (m->pages)
1579                         con->in_msg_pos.page_pos = data_off & ~PAGE_MASK;
1580                 else
1581                         con->in_msg_pos.page_pos = 0;
1582                 con->in_msg_pos.data_pos = 0;
1583         }
1584
1585         /* front */
1586         ret = read_partial_message_section(con, &m->front, front_len,
1587                                            &con->in_front_crc);
1588         if (ret <= 0)
1589                 return ret;
1590
1591         /* middle */
1592         if (m->middle) {
1593                 ret = read_partial_message_section(con, &m->middle->vec,
1594                                                    middle_len,
1595                                                    &con->in_middle_crc);
1596                 if (ret <= 0)
1597                         return ret;
1598         }
1599 #ifdef CONFIG_BLOCK
1600         if (m->bio && !m->bio_iter)
1601                 init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg);
1602 #endif
1603
1604         /* (page) data */
1605         while (con->in_msg_pos.data_pos < data_len) {
1606                 if (m->pages) {
1607                         ret = read_partial_message_pages(con, m->pages,
1608                                                  data_len, datacrc);
1609                         if (ret <= 0)
1610                                 return ret;
1611 #ifdef CONFIG_BLOCK
1612                 } else if (m->bio) {
1613
1614                         ret = read_partial_message_bio(con,
1615                                                  &m->bio_iter, &m->bio_seg,
1616                                                  data_len, datacrc);
1617                         if (ret <= 0)
1618                                 return ret;
1619 #endif
1620                 } else {
1621                         BUG_ON(1);
1622                 }
1623         }
1624
1625         /* footer */
1626         to = sizeof(m->hdr) + sizeof(m->footer);
1627         while (con->in_base_pos < to) {
1628                 left = to - con->in_base_pos;
1629                 ret = ceph_tcp_recvmsg(con->sock, (char *)&m->footer +
1630                                        (con->in_base_pos - sizeof(m->hdr)),
1631                                        left);
1632                 if (ret <= 0)
1633                         return ret;
1634                 con->in_base_pos += ret;
1635         }
1636         dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
1637              m, front_len, m->footer.front_crc, middle_len,
1638              m->footer.middle_crc, data_len, m->footer.data_crc);
1639
1640         /* crc ok? */
1641         if (con->in_front_crc != le32_to_cpu(m->footer.front_crc)) {
1642                 pr_err("read_partial_message %p front crc %u != exp. %u\n",
1643                        m, con->in_front_crc, m->footer.front_crc);
1644                 return -EBADMSG;
1645         }
1646         if (con->in_middle_crc != le32_to_cpu(m->footer.middle_crc)) {
1647                 pr_err("read_partial_message %p middle crc %u != exp %u\n",
1648                        m, con->in_middle_crc, m->footer.middle_crc);
1649                 return -EBADMSG;
1650         }
1651         if (datacrc &&
1652             (m->footer.flags & CEPH_MSG_FOOTER_NOCRC) == 0 &&
1653             con->in_data_crc != le32_to_cpu(m->footer.data_crc)) {
1654                 pr_err("read_partial_message %p data crc %u != exp. %u\n", m,
1655                        con->in_data_crc, le32_to_cpu(m->footer.data_crc));
1656                 return -EBADMSG;
1657         }
1658
1659         return 1; /* done! */
1660 }
1661
1662 /*
1663  * Process message.  This happens in the worker thread.  The callback should
1664  * be careful not to do anything that waits on other incoming messages or it
1665  * may deadlock.
1666  */
1667 static void process_message(struct ceph_connection *con)
1668 {
1669         struct ceph_msg *msg;
1670
1671         msg = con->in_msg;
1672         con->in_msg = NULL;
1673
1674         /* if first message, set peer_name */
1675         if (con->peer_name.type == 0)
1676                 con->peer_name = msg->hdr.src;
1677
1678         con->in_seq++;
1679         mutex_unlock(&con->mutex);
1680
1681         dout("===== %p %llu from %s%lld %d=%s len %d+%d (%u %u %u) =====\n",
1682              msg, le64_to_cpu(msg->hdr.seq),
1683              ENTITY_NAME(msg->hdr.src),
1684              le16_to_cpu(msg->hdr.type),
1685              ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
1686              le32_to_cpu(msg->hdr.front_len),
1687              le32_to_cpu(msg->hdr.data_len),
1688              con->in_front_crc, con->in_middle_crc, con->in_data_crc);
1689         con->ops->dispatch(con, msg);
1690
1691         mutex_lock(&con->mutex);
1692         prepare_read_tag(con);
1693 }
1694
1695
1696 /*
1697  * Write something to the socket.  Called in a worker thread when the
1698  * socket appears to be writeable and we have something ready to send.
1699  */
1700 static int try_write(struct ceph_connection *con)
1701 {
1702         struct ceph_messenger *msgr = con->msgr;
1703         int ret = 1;
1704
1705         dout("try_write start %p state %lu nref %d\n", con, con->state,
1706              atomic_read(&con->nref));
1707
1708 more:
1709         dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
1710
1711         /* open the socket first? */
1712         if (con->sock == NULL) {
1713                 /*
1714                  * if we were STANDBY and are reconnecting _this_
1715                  * connection, bump connect_seq now.  Always bump
1716                  * global_seq.
1717                  */
1718                 if (test_and_clear_bit(STANDBY, &con->state))
1719                         con->connect_seq++;
1720
1721                 prepare_write_banner(msgr, con);
1722                 prepare_write_connect(msgr, con, 1);
1723                 prepare_read_banner(con);
1724                 set_bit(CONNECTING, &con->state);
1725                 clear_bit(NEGOTIATING, &con->state);
1726
1727                 BUG_ON(con->in_msg);
1728                 con->in_tag = CEPH_MSGR_TAG_READY;
1729                 dout("try_write initiating connect on %p new state %lu\n",
1730                      con, con->state);
1731                 con->sock = ceph_tcp_connect(con);
1732                 if (IS_ERR(con->sock)) {
1733                         con->sock = NULL;
1734                         con->error_msg = "connect error";
1735                         ret = -1;
1736                         goto out;
1737                 }
1738         }
1739
1740 more_kvec:
1741         /* kvec data queued? */
1742         if (con->out_skip) {
1743                 ret = write_partial_skip(con);
1744                 if (ret <= 0)
1745                         goto done;
1746                 if (ret < 0) {
1747                         dout("try_write write_partial_skip err %d\n", ret);
1748                         goto done;
1749                 }
1750         }
1751         if (con->out_kvec_left) {
1752                 ret = write_partial_kvec(con);
1753                 if (ret <= 0)
1754                         goto done;
1755         }
1756
1757         /* msg pages? */
1758         if (con->out_msg) {
1759                 if (con->out_msg_done) {
1760                         ceph_msg_put(con->out_msg);
1761                         con->out_msg = NULL;   /* we're done with this one */
1762                         goto do_next;
1763                 }
1764
1765                 ret = write_partial_msg_pages(con);
1766                 if (ret == 1)
1767                         goto more_kvec;  /* we need to send the footer, too! */
1768                 if (ret == 0)
1769                         goto done;
1770                 if (ret < 0) {
1771                         dout("try_write write_partial_msg_pages err %d\n",
1772                              ret);
1773                         goto done;
1774                 }
1775         }
1776
1777 do_next:
1778         if (!test_bit(CONNECTING, &con->state)) {
1779                 /* is anything else pending? */
1780                 if (!list_empty(&con->out_queue)) {
1781                         prepare_write_message(con);
1782                         goto more;
1783                 }
1784                 if (con->in_seq > con->in_seq_acked) {
1785                         prepare_write_ack(con);
1786                         goto more;
1787                 }
1788                 if (test_and_clear_bit(KEEPALIVE_PENDING, &con->state)) {
1789                         prepare_write_keepalive(con);
1790                         goto more;
1791                 }
1792         }
1793
1794         /* Nothing to do! */
1795         clear_bit(WRITE_PENDING, &con->state);
1796         dout("try_write nothing else to write.\n");
1797 done:
1798         ret = 0;
1799 out:
1800         dout("try_write done on %p\n", con);
1801         return ret;
1802 }
1803
1804
1805
1806 /*
1807  * Read what we can from the socket.
1808  */
1809 static int try_read(struct ceph_connection *con)
1810 {
1811         int ret = -1;
1812
1813         if (!con->sock)
1814                 return 0;
1815
1816         if (test_bit(STANDBY, &con->state))
1817                 return 0;
1818
1819         dout("try_read start on %p\n", con);
1820
1821 more:
1822         dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,
1823              con->in_base_pos);
1824         if (test_bit(CONNECTING, &con->state)) {
1825                 if (!test_bit(NEGOTIATING, &con->state)) {
1826                         dout("try_read connecting\n");
1827                         ret = read_partial_banner(con);
1828                         if (ret <= 0)
1829                                 goto done;
1830                         if (process_banner(con) < 0) {
1831                                 ret = -1;
1832                                 goto out;
1833                         }
1834                 }
1835                 ret = read_partial_connect(con);
1836                 if (ret <= 0)
1837                         goto done;
1838                 if (process_connect(con) < 0) {
1839                         ret = -1;
1840                         goto out;
1841                 }
1842                 goto more;
1843         }
1844
1845         if (con->in_base_pos < 0) {
1846                 /*
1847                  * skipping + discarding content.
1848                  *
1849                  * FIXME: there must be a better way to do this!
1850                  */
1851                 static char buf[1024];
1852                 int skip = min(1024, -con->in_base_pos);
1853                 dout("skipping %d / %d bytes\n", skip, -con->in_base_pos);
1854                 ret = ceph_tcp_recvmsg(con->sock, buf, skip);
1855                 if (ret <= 0)
1856                         goto done;
1857                 con->in_base_pos += ret;
1858                 if (con->in_base_pos)
1859                         goto more;
1860         }
1861         if (con->in_tag == CEPH_MSGR_TAG_READY) {
1862                 /*
1863                  * what's next?
1864                  */
1865                 ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
1866                 if (ret <= 0)
1867                         goto done;
1868                 dout("try_read got tag %d\n", (int)con->in_tag);
1869                 switch (con->in_tag) {
1870                 case CEPH_MSGR_TAG_MSG:
1871                         prepare_read_message(con);
1872                         break;
1873                 case CEPH_MSGR_TAG_ACK:
1874                         prepare_read_ack(con);
1875                         break;
1876                 case CEPH_MSGR_TAG_CLOSE:
1877                         set_bit(CLOSED, &con->state);   /* fixme */
1878                         goto done;
1879                 default:
1880                         goto bad_tag;
1881                 }
1882         }
1883         if (con->in_tag == CEPH_MSGR_TAG_MSG) {
1884                 ret = read_partial_message(con);
1885                 if (ret <= 0) {
1886                         switch (ret) {
1887                         case -EBADMSG:
1888                                 con->error_msg = "bad crc";
1889                                 ret = -EIO;
1890                                 goto out;
1891                         case -EIO:
1892                                 con->error_msg = "io error";
1893                                 goto out;
1894                         default:
1895                                 goto done;
1896                         }
1897                 }
1898                 if (con->in_tag == CEPH_MSGR_TAG_READY)
1899                         goto more;
1900                 process_message(con);
1901                 goto more;
1902         }
1903         if (con->in_tag == CEPH_MSGR_TAG_ACK) {
1904                 ret = read_partial_ack(con);
1905                 if (ret <= 0)
1906                         goto done;
1907                 process_ack(con);
1908                 goto more;
1909         }
1910
1911 done:
1912         ret = 0;
1913 out:
1914         dout("try_read done on %p\n", con);
1915         return ret;
1916
1917 bad_tag:
1918         pr_err("try_read bad con->in_tag = %d\n", (int)con->in_tag);
1919         con->error_msg = "protocol error, garbage tag";
1920         ret = -1;
1921         goto out;
1922 }
1923
1924
1925 /*
1926  * Atomically queue work on a connection.  Bump @con reference to
1927  * avoid races with connection teardown.
1928  *
1929  * There is some trickery going on with QUEUED and BUSY because we
1930  * only want a _single_ thread operating on each connection at any
1931  * point in time, but we want to use all available CPUs.
1932  *
1933  * The worker thread only proceeds if it can atomically set BUSY.  It
1934  * clears QUEUED and does it's thing.  When it thinks it's done, it
1935  * clears BUSY, then rechecks QUEUED.. if it's set again, it loops
1936  * (tries again to set BUSY).
1937  *
1938  * To queue work, we first set QUEUED, _then_ if BUSY isn't set, we
1939  * try to queue work.  If that fails (work is already queued, or BUSY)
1940  * we give up (work also already being done or is queued) but leave QUEUED
1941  * set so that the worker thread will loop if necessary.
1942  */
1943 static void queue_con(struct ceph_connection *con)
1944 {
1945         if (test_bit(DEAD, &con->state)) {
1946                 dout("queue_con %p ignoring: DEAD\n",
1947                      con);
1948                 return;
1949         }
1950
1951         if (!con->ops->get(con)) {
1952                 dout("queue_con %p ref count 0\n", con);
1953                 return;
1954         }
1955
1956         set_bit(QUEUED, &con->state);
1957         if (test_bit(BUSY, &con->state)) {
1958                 dout("queue_con %p - already BUSY\n", con);
1959                 con->ops->put(con);
1960         } else if (!queue_work(ceph_msgr_wq, &con->work.work)) {
1961                 dout("queue_con %p - already queued\n", con);
1962                 con->ops->put(con);
1963         } else {
1964                 dout("queue_con %p\n", con);
1965         }
1966 }
1967
1968 /*
1969  * Do some work on a connection.  Drop a connection ref when we're done.
1970  */
1971 static void con_work(struct work_struct *work)
1972 {
1973         struct ceph_connection *con = container_of(work, struct ceph_connection,
1974                                                    work.work);
1975         int backoff = 0;
1976
1977 more:
1978         if (test_and_set_bit(BUSY, &con->state) != 0) {
1979                 dout("con_work %p BUSY already set\n", con);
1980                 goto out;
1981         }
1982         dout("con_work %p start, clearing QUEUED\n", con);
1983         clear_bit(QUEUED, &con->state);
1984
1985         mutex_lock(&con->mutex);
1986
1987         if (test_bit(CLOSED, &con->state)) { /* e.g. if we are replaced */
1988                 dout("con_work CLOSED\n");
1989                 con_close_socket(con);
1990                 goto done;
1991         }
1992         if (test_and_clear_bit(OPENING, &con->state)) {
1993                 /* reopen w/ new peer */
1994                 dout("con_work OPENING\n");
1995                 con_close_socket(con);
1996         }
1997
1998         if (test_and_clear_bit(SOCK_CLOSED, &con->state) ||
1999             try_read(con) < 0 ||
2000             try_write(con) < 0) {
2001                 mutex_unlock(&con->mutex);
2002                 backoff = 1;
2003                 ceph_fault(con);     /* error/fault path */
2004                 goto done_unlocked;
2005         }
2006
2007 done:
2008         mutex_unlock(&con->mutex);
2009
2010 done_unlocked:
2011         clear_bit(BUSY, &con->state);
2012         dout("con->state=%lu\n", con->state);
2013         if (test_bit(QUEUED, &con->state)) {
2014                 if (!backoff || test_bit(OPENING, &con->state)) {
2015                         dout("con_work %p QUEUED reset, looping\n", con);
2016                         goto more;
2017                 }
2018                 dout("con_work %p QUEUED reset, but just faulted\n", con);
2019                 clear_bit(QUEUED, &con->state);
2020         }
2021         dout("con_work %p done\n", con);
2022
2023 out:
2024         con->ops->put(con);
2025 }
2026
2027
2028 /*
2029  * Generic error/fault handler.  A retry mechanism is used with
2030  * exponential backoff
2031  */
2032 static void ceph_fault(struct ceph_connection *con)
2033 {
2034         pr_err("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
2035                ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg);
2036         dout("fault %p state %lu to peer %s\n",
2037              con, con->state, ceph_pr_addr(&con->peer_addr.in_addr));
2038
2039         if (test_bit(LOSSYTX, &con->state)) {
2040                 dout("fault on LOSSYTX channel\n");
2041                 goto out;
2042         }
2043
2044         mutex_lock(&con->mutex);
2045         if (test_bit(CLOSED, &con->state))
2046                 goto out_unlock;
2047
2048         con_close_socket(con);
2049
2050         if (con->in_msg) {
2051                 ceph_msg_put(con->in_msg);
2052                 con->in_msg = NULL;
2053         }
2054
2055         /* Requeue anything that hasn't been acked */
2056         list_splice_init(&con->out_sent, &con->out_queue);
2057
2058         /* If there are no messages in the queue, place the connection
2059          * in a STANDBY state (i.e., don't try to reconnect just yet). */
2060         if (list_empty(&con->out_queue) && !con->out_keepalive_pending) {
2061                 dout("fault setting STANDBY\n");
2062                 set_bit(STANDBY, &con->state);
2063         } else {
2064                 /* retry after a delay. */
2065                 if (con->delay == 0)
2066                         con->delay = BASE_DELAY_INTERVAL;
2067                 else if (con->delay < MAX_DELAY_INTERVAL)
2068                         con->delay *= 2;
2069                 dout("fault queueing %p delay %lu\n", con, con->delay);
2070                 con->ops->get(con);
2071                 if (queue_delayed_work(ceph_msgr_wq, &con->work,
2072                                        round_jiffies_relative(con->delay)) == 0)
2073                         con->ops->put(con);
2074         }
2075
2076 out_unlock:
2077         mutex_unlock(&con->mutex);
2078 out:
2079         /*
2080          * in case we faulted due to authentication, invalidate our
2081          * current tickets so that we can get new ones.
2082          */
2083         if (con->auth_retry && con->ops->invalidate_authorizer) {
2084                 dout("calling invalidate_authorizer()\n");
2085                 con->ops->invalidate_authorizer(con);
2086         }
2087
2088         if (con->ops->fault)
2089                 con->ops->fault(con);
2090 }
2091
2092
2093
2094 /*
2095  * create a new messenger instance
2096  */
2097 struct ceph_messenger *ceph_messenger_create(struct ceph_entity_addr *myaddr,
2098                                              u32 supported_features,
2099                                              u32 required_features)
2100 {
2101         struct ceph_messenger *msgr;
2102
2103         msgr = kzalloc(sizeof(*msgr), GFP_KERNEL);
2104         if (msgr == NULL)
2105                 return ERR_PTR(-ENOMEM);
2106
2107         msgr->supported_features = supported_features;
2108         msgr->required_features = required_features;
2109
2110         spin_lock_init(&msgr->global_seq_lock);
2111
2112         /* the zero page is needed if a request is "canceled" while the message
2113          * is being written over the socket */
2114         msgr->zero_page = __page_cache_alloc(GFP_KERNEL | __GFP_ZERO);
2115         if (!msgr->zero_page) {
2116                 kfree(msgr);
2117                 return ERR_PTR(-ENOMEM);
2118         }
2119         kmap(msgr->zero_page);
2120
2121         if (myaddr)
2122                 msgr->inst.addr = *myaddr;
2123
2124         /* select a random nonce */
2125         msgr->inst.addr.type = 0;
2126         get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
2127         encode_my_addr(msgr);
2128
2129         dout("messenger_create %p\n", msgr);
2130         return msgr;
2131 }
2132 EXPORT_SYMBOL(ceph_messenger_create);
2133
2134 void ceph_messenger_destroy(struct ceph_messenger *msgr)
2135 {
2136         dout("destroy %p\n", msgr);
2137         kunmap(msgr->zero_page);
2138         __free_page(msgr->zero_page);
2139         kfree(msgr);
2140         dout("destroyed messenger %p\n", msgr);
2141 }
2142 EXPORT_SYMBOL(ceph_messenger_destroy);
2143
2144 /*
2145  * Queue up an outgoing message on the given connection.
2146  */
2147 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
2148 {
2149         if (test_bit(CLOSED, &con->state)) {
2150                 dout("con_send %p closed, dropping %p\n", con, msg);
2151                 ceph_msg_put(msg);
2152                 return;
2153         }
2154
2155         /* set src+dst */
2156         msg->hdr.src = con->msgr->inst.name;
2157
2158         BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
2159
2160         msg->needs_out_seq = true;
2161
2162         /* queue */
2163         mutex_lock(&con->mutex);
2164         BUG_ON(!list_empty(&msg->list_head));
2165         list_add_tail(&msg->list_head, &con->out_queue);
2166         dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
2167              ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
2168              ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
2169              le32_to_cpu(msg->hdr.front_len),
2170              le32_to_cpu(msg->hdr.middle_len),
2171              le32_to_cpu(msg->hdr.data_len));
2172         mutex_unlock(&con->mutex);
2173
2174         /* if there wasn't anything waiting to send before, queue
2175          * new work */
2176         if (test_and_set_bit(WRITE_PENDING, &con->state) == 0)
2177                 queue_con(con);
2178 }
2179 EXPORT_SYMBOL(ceph_con_send);
2180
2181 /*
2182  * Revoke a message that was previously queued for send
2183  */
2184 void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg)
2185 {
2186         mutex_lock(&con->mutex);
2187         if (!list_empty(&msg->list_head)) {
2188                 dout("con_revoke %p msg %p - was on queue\n", con, msg);
2189                 list_del_init(&msg->list_head);
2190                 ceph_msg_put(msg);
2191                 msg->hdr.seq = 0;
2192         }
2193         if (con->out_msg == msg) {
2194                 dout("con_revoke %p msg %p - was sending\n", con, msg);
2195                 con->out_msg = NULL;
2196                 if (con->out_kvec_is_msg) {
2197                         con->out_skip = con->out_kvec_bytes;
2198                         con->out_kvec_is_msg = false;
2199                 }
2200                 ceph_msg_put(msg);
2201                 msg->hdr.seq = 0;
2202         }
2203         mutex_unlock(&con->mutex);
2204 }
2205
2206 /*
2207  * Revoke a message that we may be reading data into
2208  */
2209 void ceph_con_revoke_message(struct ceph_connection *con, struct ceph_msg *msg)
2210 {
2211         mutex_lock(&con->mutex);
2212         if (con->in_msg && con->in_msg == msg) {
2213                 unsigned front_len = le32_to_cpu(con->in_hdr.front_len);
2214                 unsigned middle_len = le32_to_cpu(con->in_hdr.middle_len);
2215                 unsigned data_len = le32_to_cpu(con->in_hdr.data_len);
2216
2217                 /* skip rest of message */
2218                 dout("con_revoke_pages %p msg %p revoked\n", con, msg);
2219                         con->in_base_pos = con->in_base_pos -
2220                                 sizeof(struct ceph_msg_header) -
2221                                 front_len -
2222                                 middle_len -
2223                                 data_len -
2224                                 sizeof(struct ceph_msg_footer);
2225                 ceph_msg_put(con->in_msg);
2226                 con->in_msg = NULL;
2227                 con->in_tag = CEPH_MSGR_TAG_READY;
2228                 con->in_seq++;
2229         } else {
2230                 dout("con_revoke_pages %p msg %p pages %p no-op\n",
2231                      con, con->in_msg, msg);
2232         }
2233         mutex_unlock(&con->mutex);
2234 }
2235
2236 /*
2237  * Queue a keepalive byte to ensure the tcp connection is alive.
2238  */
2239 void ceph_con_keepalive(struct ceph_connection *con)
2240 {
2241         if (test_and_set_bit(KEEPALIVE_PENDING, &con->state) == 0 &&
2242             test_and_set_bit(WRITE_PENDING, &con->state) == 0)
2243                 queue_con(con);
2244 }
2245 EXPORT_SYMBOL(ceph_con_keepalive);
2246
2247
2248 /*
2249  * construct a new message with given type, size
2250  * the new msg has a ref count of 1.
2251  */
2252 struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags)
2253 {
2254         struct ceph_msg *m;
2255
2256         m = kmalloc(sizeof(*m), flags);
2257         if (m == NULL)
2258                 goto out;
2259         kref_init(&m->kref);
2260         INIT_LIST_HEAD(&m->list_head);
2261
2262         m->hdr.tid = 0;
2263         m->hdr.type = cpu_to_le16(type);
2264         m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
2265         m->hdr.version = 0;
2266         m->hdr.front_len = cpu_to_le32(front_len);
2267         m->hdr.middle_len = 0;
2268         m->hdr.data_len = 0;
2269         m->hdr.data_off = 0;
2270         m->hdr.reserved = 0;
2271         m->footer.front_crc = 0;
2272         m->footer.middle_crc = 0;
2273         m->footer.data_crc = 0;
2274         m->footer.flags = 0;
2275         m->front_max = front_len;
2276         m->front_is_vmalloc = false;
2277         m->more_to_follow = false;
2278         m->pool = NULL;
2279
2280         /* front */
2281         if (front_len) {
2282                 if (front_len > PAGE_CACHE_SIZE) {
2283                         m->front.iov_base = __vmalloc(front_len, flags,
2284                                                       PAGE_KERNEL);
2285                         m->front_is_vmalloc = true;
2286                 } else {
2287                         m->front.iov_base = kmalloc(front_len, flags);
2288                 }
2289                 if (m->front.iov_base == NULL) {
2290                         pr_err("msg_new can't allocate %d bytes\n",
2291                              front_len);
2292                         goto out2;
2293                 }
2294         } else {
2295                 m->front.iov_base = NULL;
2296         }
2297         m->front.iov_len = front_len;
2298
2299         /* middle */
2300         m->middle = NULL;
2301
2302         /* data */
2303         m->nr_pages = 0;
2304         m->pages = NULL;
2305         m->pagelist = NULL;
2306         m->bio = NULL;
2307         m->bio_iter = NULL;
2308         m->bio_seg = 0;
2309         m->trail = NULL;
2310
2311         dout("ceph_msg_new %p front %d\n", m, front_len);
2312         return m;
2313
2314 out2:
2315         ceph_msg_put(m);
2316 out:
2317         pr_err("msg_new can't create type %d front %d\n", type, front_len);
2318         return NULL;
2319 }
2320 EXPORT_SYMBOL(ceph_msg_new);
2321
2322 /*
2323  * Allocate "middle" portion of a message, if it is needed and wasn't
2324  * allocated by alloc_msg.  This allows us to read a small fixed-size
2325  * per-type header in the front and then gracefully fail (i.e.,
2326  * propagate the error to the caller based on info in the front) when
2327  * the middle is too large.
2328  */
2329 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
2330 {
2331         int type = le16_to_cpu(msg->hdr.type);
2332         int middle_len = le32_to_cpu(msg->hdr.middle_len);
2333
2334         dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
2335              ceph_msg_type_name(type), middle_len);
2336         BUG_ON(!middle_len);
2337         BUG_ON(msg->middle);
2338
2339         msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
2340         if (!msg->middle)
2341                 return -ENOMEM;
2342         return 0;
2343 }
2344
2345 /*
2346  * Generic message allocator, for incoming messages.
2347  */
2348 static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
2349                                 struct ceph_msg_header *hdr,
2350                                 int *skip)
2351 {
2352         int type = le16_to_cpu(hdr->type);
2353         int front_len = le32_to_cpu(hdr->front_len);
2354         int middle_len = le32_to_cpu(hdr->middle_len);
2355         struct ceph_msg *msg = NULL;
2356         int ret;
2357
2358         if (con->ops->alloc_msg) {
2359                 mutex_unlock(&con->mutex);
2360                 msg = con->ops->alloc_msg(con, hdr, skip);
2361                 mutex_lock(&con->mutex);
2362                 if (!msg || *skip)
2363                         return NULL;
2364         }
2365         if (!msg) {
2366                 *skip = 0;
2367                 msg = ceph_msg_new(type, front_len, GFP_NOFS);
2368                 if (!msg) {
2369                         pr_err("unable to allocate msg type %d len %d\n",
2370                                type, front_len);
2371                         return NULL;
2372                 }
2373         }
2374         memcpy(&msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
2375
2376         if (middle_len && !msg->middle) {
2377                 ret = ceph_alloc_middle(con, msg);
2378                 if (ret < 0) {
2379                         ceph_msg_put(msg);
2380                         return NULL;
2381                 }
2382         }
2383
2384         return msg;
2385 }
2386
2387
2388 /*
2389  * Free a generically kmalloc'd message.
2390  */
2391 void ceph_msg_kfree(struct ceph_msg *m)
2392 {
2393         dout("msg_kfree %p\n", m);
2394         if (m->front_is_vmalloc)
2395                 vfree(m->front.iov_base);
2396         else
2397                 kfree(m->front.iov_base);
2398         kfree(m);
2399 }
2400
2401 /*
2402  * Drop a msg ref.  Destroy as needed.
2403  */
2404 void ceph_msg_last_put(struct kref *kref)
2405 {
2406         struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
2407
2408         dout("ceph_msg_put last one on %p\n", m);
2409         WARN_ON(!list_empty(&m->list_head));
2410
2411         /* drop middle, data, if any */
2412         if (m->middle) {
2413                 ceph_buffer_put(m->middle);
2414                 m->middle = NULL;
2415         }
2416         m->nr_pages = 0;
2417         m->pages = NULL;
2418
2419         if (m->pagelist) {
2420                 ceph_pagelist_release(m->pagelist);
2421                 kfree(m->pagelist);
2422                 m->pagelist = NULL;
2423         }
2424
2425         m->trail = NULL;
2426
2427         if (m->pool)
2428                 ceph_msgpool_put(m->pool, m);
2429         else
2430                 ceph_msg_kfree(m);
2431 }
2432 EXPORT_SYMBOL(ceph_msg_last_put);
2433
2434 void ceph_msg_dump(struct ceph_msg *msg)
2435 {
2436         pr_debug("msg_dump %p (front_max %d nr_pages %d)\n", msg,
2437                  msg->front_max, msg->nr_pages);
2438         print_hex_dump(KERN_DEBUG, "header: ",
2439                        DUMP_PREFIX_OFFSET, 16, 1,
2440                        &msg->hdr, sizeof(msg->hdr), true);
2441         print_hex_dump(KERN_DEBUG, " front: ",
2442                        DUMP_PREFIX_OFFSET, 16, 1,
2443                        msg->front.iov_base, msg->front.iov_len, true);
2444         if (msg->middle)
2445                 print_hex_dump(KERN_DEBUG, "middle: ",
2446                                DUMP_PREFIX_OFFSET, 16, 1,
2447                                msg->middle->vec.iov_base,
2448                                msg->middle->vec.iov_len, true);
2449         print_hex_dump(KERN_DEBUG, "footer: ",
2450                        DUMP_PREFIX_OFFSET, 16, 1,
2451                        &msg->footer, sizeof(msg->footer), true);
2452 }
2453 EXPORT_SYMBOL(ceph_msg_dump);