fs/ceph/messenger.c

   1 #include "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 <net/tcp.h>
  13
  14 #include "super.h"
  15 #include "messenger.h"
  16 #include "decode.h"
  17 #include "pagelist.h"
  18
  19 /*
  20  * Ceph uses the messenger to exchange ceph_msg messages with other
  21  * hosts in the system.  The messenger provides ordered and reliable
  22  * delivery.  We tolerate TCP disconnects by reconnecting (with
  23  * exponential backoff) in the case of a fault (disconnection, bad
  24  * crc, protocol error).  Acks allow sent messages to be discarded by
  25  * the sender.
  26  */
  27
  28 /* static tag bytes (protocol control messages) */
  29 static char tag_msg = CEPH_MSGR_TAG_MSG;
  30 static char tag_ack = CEPH_MSGR_TAG_ACK;
  31 static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
  32
  33 #ifdef CONFIG_LOCKDEP
  34 static struct lock_class_key socket_class;
  35 #endif
  36
  37
  38 static void queue_con(struct ceph_connection *con);
  39 static void con_work(struct work_struct *);
  40 static void ceph_fault(struct ceph_connection *con);
  41
  42 /*
  43  * nicely render a sockaddr as a string.
  44  */
  45 #define MAX_ADDR_STR 20
  46 static char addr_str[MAX_ADDR_STR][40];
  47 static DEFINE_SPINLOCK(addr_str_lock);
  48 static int last_addr_str;
  49
  50 const char *pr_addr(const struct sockaddr_storage *ss)
  51 {
  52         int i;
  53         char *s;
  54         struct sockaddr_in *in4 = (void *)ss;
  55         unsigned char *quad = (void *)&in4->sin_addr.s_addr;
  56         struct sockaddr_in6 *in6 = (void *)ss;
  57
  58         spin_lock(&addr_str_lock);
  59         i = last_addr_str++;
  60         if (last_addr_str == MAX_ADDR_STR)
  61                 last_addr_str = 0;
  62         spin_unlock(&addr_str_lock);
  63         s = addr_str[i];
  64
  65         switch (ss->ss_family) {
  66         case AF_INET:
  67                 sprintf(s, "%u.%u.%u.%u:%u",
  68                         (unsigned int)quad[0],
  69                         (unsigned int)quad[1],
  70                         (unsigned int)quad[2],
  71                         (unsigned int)quad[3],
  72                         (unsigned int)ntohs(in4->sin_port));
  73                 break;
  74
  75         case AF_INET6:
  76                 sprintf(s, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%u",
  77                         in6->sin6_addr.s6_addr16[0],
  78                         in6->sin6_addr.s6_addr16[1],
  79                         in6->sin6_addr.s6_addr16[2],
  80                         in6->sin6_addr.s6_addr16[3],
  81                         in6->sin6_addr.s6_addr16[4],
  82                         in6->sin6_addr.s6_addr16[5],
  83                         in6->sin6_addr.s6_addr16[6],
  84                         in6->sin6_addr.s6_addr16[7],
  85                         (unsigned int)ntohs(in6->sin6_port));
  86                 break;
  87
  88         default:
  89                 sprintf(s, "(unknown sockaddr family %d)", (int)ss->ss_family);
  90         }
  91
  92         return s;
  93 }
  94
  95 static void encode_my_addr(struct ceph_messenger *msgr)
  96 {
  97         memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
  98         ceph_encode_addr(&msgr->my_enc_addr);
  99 }
 100
 101 /*
 102  * work queue for all reading and writing to/from the socket.
 103  */
 104 struct workqueue_struct *ceph_msgr_wq;
 105
 106 int __init ceph_msgr_init(void)
 107 {
 108         ceph_msgr_wq = create_workqueue("ceph-msgr");
 109         if (IS_ERR(ceph_msgr_wq)) {
 110                 int ret = PTR_ERR(ceph_msgr_wq);
 111                 pr_err("msgr_init failed to create workqueue: %d\n", ret);
 112                 ceph_msgr_wq = NULL;
 113                 return ret;
 114         }
 115         return 0;
 116 }
 117
 118 void ceph_msgr_exit(void)
 119 {
 120         destroy_workqueue(ceph_msgr_wq);
 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 *paddr = (struct sockaddr *)&con->peer_addr.in_addr;
 213         struct socket *sock;
 214         int ret;
 215
 216         BUG_ON(con->sock);
 217         ret = sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
 218         if (ret)
 219                 return ERR_PTR(ret);
 220         con->sock = sock;
 221         sock->sk->sk_allocation = GFP_NOFS;
 222
 223 #ifdef CONFIG_LOCKDEP
 224         lockdep_set_class(&sock->sk->sk_lock, &socket_class);
 225 #endif
 226
 227         set_sock_callbacks(sock, con);
 228
 229         dout("connect %s\n", pr_addr(&con->peer_addr.in_addr));
 230
 231         ret = sock->ops->connect(sock, paddr, sizeof(*paddr), O_NONBLOCK);
 232         if (ret == -EINPROGRESS) {
 233                 dout("connect %s EINPROGRESS sk_state = %u\n",
 234                      pr_addr(&con->peer_addr.in_addr),
 235                      sock->sk->sk_state);
 236                 ret = 0;
 237         }
 238         if (ret < 0) {
 239                 pr_err("connect %s error %d\n",
 240                        pr_addr(&con->peer_addr.in_addr), ret);
 241                 sock_release(sock);
 242                 con->sock = NULL;
 243                 con->error_msg = "connect error";
 244         }
 245
 246         if (ret < 0)
 247                 return ERR_PTR(ret);
 248         return sock;
 249 }
 250
 251 static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
 252 {
 253         struct kvec iov = {buf, len};
 254         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 255
 256         return kernel_recvmsg(sock, &msg, &iov, 1, len, msg.msg_flags);
 257 }
 258
 259 /*
 260  * write something.  @more is true if caller will be sending more data
 261  * shortly.
 262  */
 263 static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
 264                      size_t kvlen, size_t len, int more)
 265 {
 266         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 267
 268         if (more)
 269                 msg.msg_flags |= MSG_MORE;
 270         else
 271                 msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
 272
 273         return kernel_sendmsg(sock, &msg, iov, kvlen, len);
 274 }
 275
 276
 277 /*
 278  * Shutdown/close the socket for the given connection.
 279  */
 280 static int con_close_socket(struct ceph_connection *con)
 281 {
 282         int rc;
 283
 284         dout("con_close_socket on %p sock %p\n", con, con->sock);
 285         if (!con->sock)
 286                 return 0;
 287         set_bit(SOCK_CLOSED, &con->state);
 288         rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
 289         sock_release(con->sock);
 290         con->sock = NULL;
 291         clear_bit(SOCK_CLOSED, &con->state);
 292         return rc;
 293 }
 294
 295 /*
 296  * Reset a connection.  Discard all incoming and outgoing messages
 297  * and clear *_seq state.
 298  */
 299 static void ceph_msg_remove(struct ceph_msg *msg)
 300 {
 301         list_del_init(&msg->list_head);
 302         ceph_msg_put(msg);
 303 }
 304 static void ceph_msg_remove_list(struct list_head *head)
 305 {
 306         while (!list_empty(head)) {
 307                 struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
 308                                                         list_head);
 309                 ceph_msg_remove(msg);
 310         }
 311 }
 312
 313 static void reset_connection(struct ceph_connection *con)
 314 {
 315         /* reset connection, out_queue, msg_ and connect_seq */
 316         /* discard existing out_queue and msg_seq */
 317         ceph_msg_remove_list(&con->out_queue);
 318         ceph_msg_remove_list(&con->out_sent);
 319
 320         if (con->in_msg) {
 321                 ceph_msg_put(con->in_msg);
 322                 con->in_msg = NULL;
 323         }
 324
 325         con->connect_seq = 0;
 326         con->out_seq = 0;
 327         if (con->out_msg) {
 328                 ceph_msg_put(con->out_msg);
 329                 con->out_msg = NULL;
 330         }
 331         con->out_keepalive_pending = false;
 332         con->in_seq = 0;
 333         con->in_seq_acked = 0;
 334 }
 335
 336 /*
 337  * mark a peer down.  drop any open connections.
 338  */
 339 void ceph_con_close(struct ceph_connection *con)
 340 {
 341         dout("con_close %p peer %s\n", con, pr_addr(&con->peer_addr.in_addr));
 342         set_bit(CLOSED, &con->state);  /* in case there's queued work */
 343         clear_bit(STANDBY, &con->state);  /* avoid connect_seq bump */
 344         clear_bit(LOSSYTX, &con->state);  /* so we retry next connect */
 345         clear_bit(KEEPALIVE_PENDING, &con->state);
 346         clear_bit(WRITE_PENDING, &con->state);
 347         mutex_lock(&con->mutex);
 348         reset_connection(con);
 349         con->peer_global_seq = 0;
 350         cancel_delayed_work(&con->work);
 351         mutex_unlock(&con->mutex);
 352         queue_con(con);
 353 }
 354
 355 /*
 356  * Reopen a closed connection, with a new peer address.
 357  */
 358 void ceph_con_open(struct ceph_connection *con, struct ceph_entity_addr *addr)
 359 {
 360         dout("con_open %p %s\n", con, pr_addr(&addr->in_addr));
 361         set_bit(OPENING, &con->state);
 362         clear_bit(CLOSED, &con->state);
 363         memcpy(&con->peer_addr, addr, sizeof(*addr));
 364         con->delay = 0;      /* reset backoff memory */
 365         queue_con(con);
 366 }
 367
 368 /*
 369  * return true if this connection ever successfully opened
 370  */
 371 bool ceph_con_opened(struct ceph_connection *con)
 372 {
 373         return con->connect_seq > 0;
 374 }
 375
 376 /*
 377  * generic get/put
 378  */
 379 struct ceph_connection *ceph_con_get(struct ceph_connection *con)
 380 {
 381         dout("con_get %p nref = %d -> %d\n", con,
 382              atomic_read(&con->nref), atomic_read(&con->nref) + 1);
 383         if (atomic_inc_not_zero(&con->nref))
 384                 return con;
 385         return NULL;
 386 }
 387
 388 void ceph_con_put(struct ceph_connection *con)
 389 {
 390         dout("con_put %p nref = %d -> %d\n", con,
 391              atomic_read(&con->nref), atomic_read(&con->nref) - 1);
 392         BUG_ON(atomic_read(&con->nref) == 0);
 393         if (atomic_dec_and_test(&con->nref)) {
 394                 BUG_ON(con->sock);
 395                 kfree(con);
 396         }
 397 }
 398
 399 /*
 400  * initialize a new connection.
 401  */
 402 void ceph_con_init(struct ceph_messenger *msgr, struct ceph_connection *con)
 403 {
 404         dout("con_init %p\n", con);
 405         memset(con, 0, sizeof(*con));
 406         atomic_set(&con->nref, 1);
 407         con->msgr = msgr;
 408         mutex_init(&con->mutex);
 409         INIT_LIST_HEAD(&con->out_queue);
 410         INIT_LIST_HEAD(&con->out_sent);
 411         INIT_DELAYED_WORK(&con->work, con_work);
 412 }
 413
 414
 415 /*
 416  * We maintain a global counter to order connection attempts.  Get
 417  * a unique seq greater than @gt.
 418  */
 419 static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
 420 {
 421         u32 ret;
 422
 423         spin_lock(&msgr->global_seq_lock);
 424         if (msgr->global_seq < gt)
 425                 msgr->global_seq = gt;
 426         ret = ++msgr->global_seq;
 427         spin_unlock(&msgr->global_seq_lock);
 428         return ret;
 429 }
 430
 431
 432 /*
 433  * Prepare footer for currently outgoing message, and finish things
 434  * off.  Assumes out_kvec* are already valid.. we just add on to the end.
 435  */
 436 static void prepare_write_message_footer(struct ceph_connection *con, int v)
 437 {
 438         struct ceph_msg *m = con->out_msg;
 439
 440         dout("prepare_write_message_footer %p\n", con);
 441         con->out_kvec_is_msg = true;
 442         con->out_kvec[v].iov_base = &m->footer;
 443         con->out_kvec[v].iov_len = sizeof(m->footer);
 444         con->out_kvec_bytes += sizeof(m->footer);
 445         con->out_kvec_left++;
 446         con->out_more = m->more_to_follow;
 447         con->out_msg_done = true;
 448 }
 449
 450 /*
 451  * Prepare headers for the next outgoing message.
 452  */
 453 static void prepare_write_message(struct ceph_connection *con)
 454 {
 455         struct ceph_msg *m;
 456         int v = 0;
 457
 458         con->out_kvec_bytes = 0;
 459         con->out_kvec_is_msg = true;
 460         con->out_msg_done = false;
 461
 462         /* Sneak an ack in there first?  If we can get it into the same
 463          * TCP packet that's a good thing. */
 464         if (con->in_seq > con->in_seq_acked) {
 465                 con->in_seq_acked = con->in_seq;
 466                 con->out_kvec[v].iov_base = &tag_ack;
 467                 con->out_kvec[v++].iov_len = 1;
 468                 con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
 469                 con->out_kvec[v].iov_base = &con->out_temp_ack;
 470                 con->out_kvec[v++].iov_len = sizeof(con->out_temp_ack);
 471                 con->out_kvec_bytes = 1 + sizeof(con->out_temp_ack);
 472         }
 473
 474         m = list_first_entry(&con->out_queue,
 475                        struct ceph_msg, list_head);
 476         con->out_msg = m;
 477         if (test_bit(LOSSYTX, &con->state)) {
 478                 list_del_init(&m->list_head);
 479         } else {
 480                 /* put message on sent list */
 481                 ceph_msg_get(m);
 482                 list_move_tail(&m->list_head, &con->out_sent);
 483         }
 484
 485         /*
 486          * only assign outgoing seq # if we haven't sent this message
 487          * yet.  if it is requeued, resend with it's original seq.
 488          */
 489         if (m->needs_out_seq) {
 490                 m->hdr.seq = cpu_to_le64(++con->out_seq);
 491                 m->needs_out_seq = false;
 492         }
 493
 494         dout("prepare_write_message %p seq %lld type %d len %d+%d+%d %d pgs\n",
 495              m, con->out_seq, le16_to_cpu(m->hdr.type),
 496              le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
 497              le32_to_cpu(m->hdr.data_len),
 498              m->nr_pages);
 499         BUG_ON(le32_to_cpu(m->hdr.front_len) != m->front.iov_len);
 500
 501         /* tag + hdr + front + middle */
 502         con->out_kvec[v].iov_base = &tag_msg;
 503         con->out_kvec[v++].iov_len = 1;
 504         con->out_kvec[v].iov_base = &m->hdr;
 505         con->out_kvec[v++].iov_len = sizeof(m->hdr);
 506         con->out_kvec[v++] = m->front;
 507         if (m->middle)
 508                 con->out_kvec[v++] = m->middle->vec;
 509         con->out_kvec_left = v;
 510         con->out_kvec_bytes += 1 + sizeof(m->hdr) + m->front.iov_len +
 511                 (m->middle ? m->middle->vec.iov_len : 0);
 512         con->out_kvec_cur = con->out_kvec;
 513
 514         /* fill in crc (except data pages), footer */
 515         con->out_msg->hdr.crc =
 516                 cpu_to_le32(crc32c(0, (void *)&m->hdr,
 517                                       sizeof(m->hdr) - sizeof(m->hdr.crc)));
 518         con->out_msg->footer.flags = CEPH_MSG_FOOTER_COMPLETE;
 519         con->out_msg->footer.front_crc =
 520                 cpu_to_le32(crc32c(0, m->front.iov_base, m->front.iov_len));
 521         if (m->middle)
 522                 con->out_msg->footer.middle_crc =
 523                         cpu_to_le32(crc32c(0, m->middle->vec.iov_base,
 524                                            m->middle->vec.iov_len));
 525         else
 526                 con->out_msg->footer.middle_crc = 0;
 527         con->out_msg->footer.data_crc = 0;
 528         dout("prepare_write_message front_crc %u data_crc %u\n",
 529              le32_to_cpu(con->out_msg->footer.front_crc),
 530              le32_to_cpu(con->out_msg->footer.middle_crc));
 531
 532         /* is there a data payload? */
 533         if (le32_to_cpu(m->hdr.data_len) > 0) {
 534                 /* initialize page iterator */
 535                 con->out_msg_pos.page = 0;
 536                 con->out_msg_pos.page_pos =
 537                         le16_to_cpu(m->hdr.data_off) & ~PAGE_MASK;
 538                 con->out_msg_pos.data_pos = 0;
 539                 con->out_msg_pos.did_page_crc = 0;
 540                 con->out_more = 1;  /* data + footer will follow */
 541         } else {
 542                 /* no, queue up footer too and be done */
 543                 prepare_write_message_footer(con, v);
 544         }
 545
 546         set_bit(WRITE_PENDING, &con->state);
 547 }
 548
 549 /*
 550  * Prepare an ack.
 551  */
 552 static void prepare_write_ack(struct ceph_connection *con)
 553 {
 554         dout("prepare_write_ack %p %llu -> %llu\n", con,
 555              con->in_seq_acked, con->in_seq);
 556         con->in_seq_acked = con->in_seq;
 557
 558         con->out_kvec[0].iov_base = &tag_ack;
 559         con->out_kvec[0].iov_len = 1;
 560         con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
 561         con->out_kvec[1].iov_base = &con->out_temp_ack;
 562         con->out_kvec[1].iov_len = sizeof(con->out_temp_ack);
 563         con->out_kvec_left = 2;
 564         con->out_kvec_bytes = 1 + sizeof(con->out_temp_ack);
 565         con->out_kvec_cur = con->out_kvec;
 566         con->out_more = 1;  /* more will follow.. eventually.. */
 567         set_bit(WRITE_PENDING, &con->state);
 568 }
 569
 570 /*
 571  * Prepare to write keepalive byte.
 572  */
 573 static void prepare_write_keepalive(struct ceph_connection *con)
 574 {
 575         dout("prepare_write_keepalive %p\n", con);
 576         con->out_kvec[0].iov_base = &tag_keepalive;
 577         con->out_kvec[0].iov_len = 1;
 578         con->out_kvec_left = 1;
 579         con->out_kvec_bytes = 1;
 580         con->out_kvec_cur = con->out_kvec;
 581         set_bit(WRITE_PENDING, &con->state);
 582 }
 583
 584 /*
 585  * Connection negotiation.
 586  */
 587
 588 static void prepare_connect_authorizer(struct ceph_connection *con)
 589 {
 590         void *auth_buf;
 591         int auth_len = 0;
 592         int auth_protocol = 0;
 593
 594         mutex_unlock(&con->mutex);
 595         if (con->ops->get_authorizer)
 596                 con->ops->get_authorizer(con, &auth_buf, &auth_len,
 597                                          &auth_protocol, &con->auth_reply_buf,
 598                                          &con->auth_reply_buf_len,
 599                                          con->auth_retry);
 600         mutex_lock(&con->mutex);
 601
 602         con->out_connect.authorizer_protocol = cpu_to_le32(auth_protocol);
 603         con->out_connect.authorizer_len = cpu_to_le32(auth_len);
 604
 605         con->out_kvec[con->out_kvec_left].iov_base = auth_buf;
 606         con->out_kvec[con->out_kvec_left].iov_len = auth_len;
 607         con->out_kvec_left++;
 608         con->out_kvec_bytes += auth_len;
 609 }
 610
 611 /*
 612  * We connected to a peer and are saying hello.
 613  */
 614 static void prepare_write_banner(struct ceph_messenger *msgr,
 615                                  struct ceph_connection *con)
 616 {
 617         int len = strlen(CEPH_BANNER);
 618
 619         con->out_kvec[0].iov_base = CEPH_BANNER;
 620         con->out_kvec[0].iov_len = len;
 621         con->out_kvec[1].iov_base = &msgr->my_enc_addr;
 622         con->out_kvec[1].iov_len = sizeof(msgr->my_enc_addr);
 623         con->out_kvec_left = 2;
 624         con->out_kvec_bytes = len + sizeof(msgr->my_enc_addr);
 625         con->out_kvec_cur = con->out_kvec;
 626         con->out_more = 0;
 627         set_bit(WRITE_PENDING, &con->state);
 628 }
 629
 630 static void prepare_write_connect(struct ceph_messenger *msgr,
 631                                   struct ceph_connection *con,
 632                                   int after_banner)
 633 {
 634         unsigned global_seq = get_global_seq(con->msgr, 0);
 635         int proto;
 636
 637         switch (con->peer_name.type) {
 638         case CEPH_ENTITY_TYPE_MON:
 639                 proto = CEPH_MONC_PROTOCOL;
 640                 break;
 641         case CEPH_ENTITY_TYPE_OSD:
 642                 proto = CEPH_OSDC_PROTOCOL;
 643                 break;
 644         case CEPH_ENTITY_TYPE_MDS:
 645                 proto = CEPH_MDSC_PROTOCOL;
 646                 break;
 647         default:
 648                 BUG();
 649         }
 650
 651         dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
 652              con->connect_seq, global_seq, proto);
 653
 654         con->out_connect.features = CEPH_FEATURE_SUPPORTED_CLIENT;
 655         con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
 656         con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
 657         con->out_connect.global_seq = cpu_to_le32(global_seq);
 658         con->out_connect.protocol_version = cpu_to_le32(proto);
 659         con->out_connect.flags = 0;
 660
 661         if (!after_banner) {
 662                 con->out_kvec_left = 0;
 663                 con->out_kvec_bytes = 0;
 664         }
 665         con->out_kvec[con->out_kvec_left].iov_base = &con->out_connect;
 666         con->out_kvec[con->out_kvec_left].iov_len = sizeof(con->out_connect);
 667         con->out_kvec_left++;
 668         con->out_kvec_bytes += sizeof(con->out_connect);
 669         con->out_kvec_cur = con->out_kvec;
 670         con->out_more = 0;
 671         set_bit(WRITE_PENDING, &con->state);
 672
 673         prepare_connect_authorizer(con);
 674 }
 675
 676
 677 /*
 678  * write as much of pending kvecs to the socket as we can.
 679  *  1 -> done
 680  *  0 -> socket full, but more to do
 681  * <0 -> error
 682  */
 683 static int write_partial_kvec(struct ceph_connection *con)
 684 {
 685         int ret;
 686
 687         dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
 688         while (con->out_kvec_bytes > 0) {
 689                 ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
 690                                        con->out_kvec_left, con->out_kvec_bytes,
 691                                        con->out_more);
 692                 if (ret <= 0)
 693                         goto out;
 694                 con->out_kvec_bytes -= ret;
 695                 if (con->out_kvec_bytes == 0)
 696                         break;            /* done */
 697                 while (ret > 0) {
 698                         if (ret >= con->out_kvec_cur->iov_len) {
 699                                 ret -= con->out_kvec_cur->iov_len;
 700                                 con->out_kvec_cur++;
 701                                 con->out_kvec_left--;
 702                         } else {
 703                                 con->out_kvec_cur->iov_len -= ret;
 704                                 con->out_kvec_cur->iov_base += ret;
 705                                 ret = 0;
 706                                 break;
 707                         }
 708                 }
 709         }
 710         con->out_kvec_left = 0;
 711         con->out_kvec_is_msg = false;
 712         ret = 1;
 713 out:
 714         dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
 715              con->out_kvec_bytes, con->out_kvec_left, ret);
 716         return ret;  /* done! */
 717 }
 718
 719 /*
 720  * Write as much message data payload as we can.  If we finish, queue
 721  * up the footer.
 722  *  1 -> done, footer is now queued in out_kvec[].
 723  *  0 -> socket full, but more to do
 724  * <0 -> error
 725  */
 726 static int write_partial_msg_pages(struct ceph_connection *con)
 727 {
 728         struct ceph_msg *msg = con->out_msg;
 729         unsigned data_len = le32_to_cpu(msg->hdr.data_len);
 730         size_t len;
 731         int crc = con->msgr->nocrc;
 732         int ret;
 733
 734         dout("write_partial_msg_pages %p msg %p page %d/%d offset %d\n",
 735              con, con->out_msg, con->out_msg_pos.page, con->out_msg->nr_pages,
 736              con->out_msg_pos.page_pos);
 737
 738         while (con->out_msg_pos.page < con->out_msg->nr_pages) {
 739                 struct page *page = NULL;
 740                 void *kaddr = NULL;
 741
 742                 /*
 743                  * if we are calculating the data crc (the default), we need
 744                  * to map the page.  if our pages[] has been revoked, use the
 745                  * zero page.
 746                  */
 747                 if (msg->pages) {
 748                         page = msg->pages[con->out_msg_pos.page];
 749                         if (crc)
 750                                 kaddr = kmap(page);
 751                 } else if (msg->pagelist) {
 752                         page = list_first_entry(&msg->pagelist->head,
 753                                                 struct page, lru);
 754                         if (crc)
 755                                 kaddr = kmap(page);
 756                 } else {
 757                         page = con->msgr->zero_page;
 758                         if (crc)
 759                                 kaddr = page_address(con->msgr->zero_page);
 760                 }
 761                 len = min((int)(PAGE_SIZE - con->out_msg_pos.page_pos),
 762                           (int)(data_len - con->out_msg_pos.data_pos));
 763                 if (crc && !con->out_msg_pos.did_page_crc) {
 764                         void *base = kaddr + con->out_msg_pos.page_pos;
 765                         u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc);
 766
 767                         BUG_ON(kaddr == NULL);
 768                         con->out_msg->footer.data_crc =
 769                                 cpu_to_le32(crc32c(tmpcrc, base, len));
 770                         con->out_msg_pos.did_page_crc = 1;
 771                 }
 772
 773                 ret = kernel_sendpage(con->sock, page,
 774                                       con->out_msg_pos.page_pos, len,
 775                                       MSG_DONTWAIT | MSG_NOSIGNAL |
 776                                       MSG_MORE);
 777
 778                 if (crc && (msg->pages || msg->pagelist))
 779                         kunmap(page);
 780
 781                 if (ret <= 0)
 782                         goto out;
 783
 784                 con->out_msg_pos.data_pos += ret;
 785                 con->out_msg_pos.page_pos += ret;
 786                 if (ret == len) {
 787                         con->out_msg_pos.page_pos = 0;
 788                         con->out_msg_pos.page++;
 789                         con->out_msg_pos.did_page_crc = 0;
 790                         if (msg->pagelist)
 791                                 list_move_tail(&page->lru,
 792                                                &msg->pagelist->head);
 793                 }
 794         }
 795
 796         dout("write_partial_msg_pages %p msg %p done\n", con, msg);
 797
 798         /* prepare and queue up footer, too */
 799         if (!crc)
 800                 con->out_msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
 801         con->out_kvec_bytes = 0;
 802         con->out_kvec_left = 0;
 803         con->out_kvec_cur = con->out_kvec;
 804         prepare_write_message_footer(con, 0);
 805         ret = 1;
 806 out:
 807         return ret;
 808 }
 809
 810 /*
 811  * write some zeros
 812  */
 813 static int write_partial_skip(struct ceph_connection *con)
 814 {
 815         int ret;
 816
 817         while (con->out_skip > 0) {
 818                 struct kvec iov = {
 819                         .iov_base = page_address(con->msgr->zero_page),
 820                         .iov_len = min(con->out_skip, (int)PAGE_CACHE_SIZE)
 821                 };
 822
 823                 ret = ceph_tcp_sendmsg(con->sock, &iov, 1, iov.iov_len, 1);
 824                 if (ret <= 0)
 825                         goto out;
 826                 con->out_skip -= ret;
 827         }
 828         ret = 1;
 829 out:
 830         return ret;
 831 }
 832
 833 /*
 834  * Prepare to read connection handshake, or an ack.
 835  */
 836 static void prepare_read_banner(struct ceph_connection *con)
 837 {
 838         dout("prepare_read_banner %p\n", con);
 839         con->in_base_pos = 0;
 840 }
 841
 842 static void prepare_read_connect(struct ceph_connection *con)
 843 {
 844         dout("prepare_read_connect %p\n", con);
 845         con->in_base_pos = 0;
 846 }
 847
 848 static void prepare_read_ack(struct ceph_connection *con)
 849 {
 850         dout("prepare_read_ack %p\n", con);
 851         con->in_base_pos = 0;
 852 }
 853
 854 static void prepare_read_tag(struct ceph_connection *con)
 855 {
 856         dout("prepare_read_tag %p\n", con);
 857         con->in_base_pos = 0;
 858         con->in_tag = CEPH_MSGR_TAG_READY;
 859 }
 860
 861 /*
 862  * Prepare to read a message.
 863  */
 864 static int prepare_read_message(struct ceph_connection *con)
 865 {
 866         dout("prepare_read_message %p\n", con);
 867         BUG_ON(con->in_msg != NULL);
 868         con->in_base_pos = 0;
 869         con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
 870         return 0;
 871 }
 872
 873
 874 static int read_partial(struct ceph_connection *con,
 875                         int *to, int size, void *object)
 876 {
 877         *to += size;
 878         while (con->in_base_pos < *to) {
 879                 int left = *to - con->in_base_pos;
 880                 int have = size - left;
 881                 int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
 882                 if (ret <= 0)
 883                         return ret;
 884                 con->in_base_pos += ret;
 885         }
 886         return 1;
 887 }
 888
 889
 890 /*
 891  * Read all or part of the connect-side handshake on a new connection
 892  */
 893 static int read_partial_banner(struct ceph_connection *con)
 894 {
 895         int ret, to = 0;
 896
 897         dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
 898
 899         /* peer's banner */
 900         ret = read_partial(con, &to, strlen(CEPH_BANNER), con->in_banner);
 901         if (ret <= 0)
 902                 goto out;
 903         ret = read_partial(con, &to, sizeof(con->actual_peer_addr),
 904                            &con->actual_peer_addr);
 905         if (ret <= 0)
 906                 goto out;
 907         ret = read_partial(con, &to, sizeof(con->peer_addr_for_me),
 908                            &con->peer_addr_for_me);
 909         if (ret <= 0)
 910                 goto out;
 911 out:
 912         return ret;
 913 }
 914
 915 static int read_partial_connect(struct ceph_connection *con)
 916 {
 917         int ret, to = 0;
 918
 919         dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
 920
 921         ret = read_partial(con, &to, sizeof(con->in_reply), &con->in_reply);
 922         if (ret <= 0)
 923                 goto out;
 924         ret = read_partial(con, &to, le32_to_cpu(con->in_reply.authorizer_len),
 925                            con->auth_reply_buf);
 926         if (ret <= 0)
 927                 goto out;
 928
 929         dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
 930              con, (int)con->in_reply.tag,
 931              le32_to_cpu(con->in_reply.connect_seq),
 932              le32_to_cpu(con->in_reply.global_seq));
 933 out:
 934         return ret;
 935
 936 }
 937
 938 /*
 939  * Verify the hello banner looks okay.
 940  */
 941 static int verify_hello(struct ceph_connection *con)
 942 {
 943         if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
 944                 pr_err("connect to %s got bad banner\n",
 945                        pr_addr(&con->peer_addr.in_addr));
 946                 con->error_msg = "protocol error, bad banner";
 947                 return -1;
 948         }
 949         return 0;
 950 }
 951
 952 static bool addr_is_blank(struct sockaddr_storage *ss)
 953 {
 954         switch (ss->ss_family) {
 955         case AF_INET:
 956                 return ((struct sockaddr_in *)ss)->sin_addr.s_addr == 0;
 957         case AF_INET6:
 958                 return
 959                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[0] == 0 &&
 960                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[1] == 0 &&
 961                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[2] == 0 &&
 962                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[3] == 0;
 963         }
 964         return false;
 965 }
 966
 967 static int addr_port(struct sockaddr_storage *ss)
 968 {
 969         switch (ss->ss_family) {
 970         case AF_INET:
 971                 return ntohs(((struct sockaddr_in *)ss)->sin_port);
 972         case AF_INET6:
 973                 return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
 974         }
 975         return 0;
 976 }
 977
 978 static void addr_set_port(struct sockaddr_storage *ss, int p)
 979 {
 980         switch (ss->ss_family) {
 981         case AF_INET:
 982                 ((struct sockaddr_in *)ss)->sin_port = htons(p);
 983         case AF_INET6:
 984                 ((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
 985         }
 986 }
 987
 988 /*
 989  * Parse an ip[:port] list into an addr array.  Use the default
 990  * monitor port if a port isn't specified.
 991  */
 992 int ceph_parse_ips(const char *c, const char *end,
 993                    struct ceph_entity_addr *addr,
 994                    int max_count, int *count)
 995 {
 996         int i;
 997         const char *p = c;
 998
 999         dout("parse_ips on '%.*s'\n", (int)(end-c), c);
1000         for (i = 0; i < max_count; i++) {
1001                 const char *ipend;
1002                 struct sockaddr_storage *ss = &addr[i].in_addr;
1003                 struct sockaddr_in *in4 = (void *)ss;
1004                 struct sockaddr_in6 *in6 = (void *)ss;
1005                 int port;
1006
1007                 memset(ss, 0, sizeof(*ss));
1008                 if (in4_pton(p, end - p, (u8 *)&in4->sin_addr.s_addr,
1009                              ',', &ipend)) {
1010                         ss->ss_family = AF_INET;
1011                 } else if (in6_pton(p, end - p, (u8 *)&in6->sin6_addr.s6_addr,
1012                                     ',', &ipend)) {
1013                         ss->ss_family = AF_INET6;
1014                 } else {
1015                         goto bad;
1016                 }
1017                 p = ipend;
1018
1019                 /* port? */
1020                 if (p < end && *p == ':') {
1021                         port = 0;
1022                         p++;
1023                         while (p < end && *p >= '0' && *p <= '9') {
1024                                 port = (port * 10) + (*p - '0');
1025                                 p++;
1026                         }
1027                         if (port > 65535 || port == 0)
1028                                 goto bad;
1029                 } else {
1030                         port = CEPH_MON_PORT;
1031                 }
1032
1033                 addr_set_port(ss, port);
1034
1035                 dout("parse_ips got %s\n", pr_addr(ss));
1036
1037                 if (p == end)
1038                         break;
1039                 if (*p != ',')
1040                         goto bad;
1041                 p++;
1042         }
1043
1044         if (p != end)
1045                 goto bad;
1046
1047         if (count)
1048                 *count = i + 1;
1049         return 0;
1050
1051 bad:
1052         pr_err("parse_ips bad ip '%s'\n", c);
1053         return -EINVAL;
1054 }
1055
1056 static int process_banner(struct ceph_connection *con)
1057 {
1058         dout("process_banner on %p\n", con);
1059
1060         if (verify_hello(con) < 0)
1061                 return -1;
1062
1063         ceph_decode_addr(&con->actual_peer_addr);
1064         ceph_decode_addr(&con->peer_addr_for_me);
1065
1066         /*
1067          * Make sure the other end is who we wanted.  note that the other
1068          * end may not yet know their ip address, so if it's 0.0.0.0, give
1069          * them the benefit of the doubt.
1070          */
1071         if (memcmp(&con->peer_addr, &con->actual_peer_addr,
1072                    sizeof(con->peer_addr)) != 0 &&
1073             !(addr_is_blank(&con->actual_peer_addr.in_addr) &&
1074               con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
1075                 pr_warning("wrong peer, want %s/%lld, got %s/%lld\n",
1076                            pr_addr(&con->peer_addr.in_addr),
1077                            le64_to_cpu(con->peer_addr.nonce),
1078                            pr_addr(&con->actual_peer_addr.in_addr),
1079                            le64_to_cpu(con->actual_peer_addr.nonce));
1080                 con->error_msg = "wrong peer at address";
1081                 return -1;
1082         }
1083
1084         /*
1085          * did we learn our address?
1086          */
1087         if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
1088                 int port = addr_port(&con->msgr->inst.addr.in_addr);
1089
1090                 memcpy(&con->msgr->inst.addr.in_addr,
1091                        &con->peer_addr_for_me.in_addr,
1092                        sizeof(con->peer_addr_for_me.in_addr));
1093                 addr_set_port(&con->msgr->inst.addr.in_addr, port);
1094                 encode_my_addr(con->msgr);
1095                 dout("process_banner learned my addr is %s\n",
1096                      pr_addr(&con->msgr->inst.addr.in_addr));
1097         }
1098
1099         set_bit(NEGOTIATING, &con->state);
1100         prepare_read_connect(con);
1101         return 0;
1102 }
1103
1104 static void fail_protocol(struct ceph_connection *con)
1105 {
1106         reset_connection(con);
1107         set_bit(CLOSED, &con->state);  /* in case there's queued work */
1108
1109         mutex_unlock(&con->mutex);
1110         if (con->ops->bad_proto)
1111                 con->ops->bad_proto(con);
1112         mutex_lock(&con->mutex);
1113 }
1114
1115 static int process_connect(struct ceph_connection *con)
1116 {
1117         u64 sup_feat = CEPH_FEATURE_SUPPORTED_CLIENT;
1118         u64 req_feat = CEPH_FEATURE_REQUIRED_CLIENT;
1119         u64 server_feat = le64_to_cpu(con->in_reply.features);
1120
1121         dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
1122
1123         switch (con->in_reply.tag) {
1124         case CEPH_MSGR_TAG_FEATURES:
1125                 pr_err("%s%lld %s feature set mismatch,"
1126                        " my %llx < server's %llx, missing %llx\n",
1127                        ENTITY_NAME(con->peer_name),
1128                        pr_addr(&con->peer_addr.in_addr),
1129                        sup_feat, server_feat, server_feat & ~sup_feat);
1130                 con->error_msg = "missing required protocol features";
1131                 fail_protocol(con);
1132                 return -1;
1133
1134         case CEPH_MSGR_TAG_BADPROTOVER:
1135                 pr_err("%s%lld %s protocol version mismatch,"
1136                        " my %d != server's %d\n",
1137                        ENTITY_NAME(con->peer_name),
1138                        pr_addr(&con->peer_addr.in_addr),
1139                        le32_to_cpu(con->out_connect.protocol_version),
1140                        le32_to_cpu(con->in_reply.protocol_version));
1141                 con->error_msg = "protocol version mismatch";
1142                 fail_protocol(con);
1143                 return -1;
1144
1145         case CEPH_MSGR_TAG_BADAUTHORIZER:
1146                 con->auth_retry++;
1147                 dout("process_connect %p got BADAUTHORIZER attempt %d\n", con,
1148                      con->auth_retry);
1149                 if (con->auth_retry == 2) {
1150                         con->error_msg = "connect authorization failure";
1151                         reset_connection(con);
1152                         set_bit(CLOSED, &con->state);
1153                         return -1;
1154                 }
1155                 con->auth_retry = 1;
1156                 prepare_write_connect(con->msgr, con, 0);
1157                 prepare_read_connect(con);
1158                 break;
1159
1160         case CEPH_MSGR_TAG_RESETSESSION:
1161                 /*
1162                  * If we connected with a large connect_seq but the peer
1163                  * has no record of a session with us (no connection, or
1164                  * connect_seq == 0), they will send RESETSESION to indicate
1165                  * that they must have reset their session, and may have
1166                  * dropped messages.
1167                  */
1168                 dout("process_connect got RESET peer seq %u\n",
1169                      le32_to_cpu(con->in_connect.connect_seq));
1170                 pr_err("%s%lld %s connection reset\n",
1171                        ENTITY_NAME(con->peer_name),
1172                        pr_addr(&con->peer_addr.in_addr));
1173                 reset_connection(con);
1174                 prepare_write_connect(con->msgr, con, 0);
1175                 prepare_read_connect(con);
1176
1177                 /* Tell ceph about it. */
1178                 mutex_unlock(&con->mutex);
1179                 pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));
1180                 if (con->ops->peer_reset)
1181                         con->ops->peer_reset(con);
1182                 mutex_lock(&con->mutex);
1183                 break;
1184
1185         case CEPH_MSGR_TAG_RETRY_SESSION:
1186                 /*
1187                  * If we sent a smaller connect_seq than the peer has, try
1188                  * again with a larger value.
1189                  */
1190                 dout("process_connect got RETRY my seq = %u, peer_seq = %u\n",
1191                      le32_to_cpu(con->out_connect.connect_seq),
1192                      le32_to_cpu(con->in_connect.connect_seq));
1193                 con->connect_seq = le32_to_cpu(con->in_connect.connect_seq);
1194                 prepare_write_connect(con->msgr, con, 0);
1195                 prepare_read_connect(con);
1196                 break;
1197
1198         case CEPH_MSGR_TAG_RETRY_GLOBAL:
1199                 /*
1200                  * If we sent a smaller global_seq than the peer has, try
1201                  * again with a larger value.
1202                  */
1203                 dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
1204                      con->peer_global_seq,
1205                      le32_to_cpu(con->in_connect.global_seq));
1206                 get_global_seq(con->msgr,
1207                                le32_to_cpu(con->in_connect.global_seq));
1208                 prepare_write_connect(con->msgr, con, 0);
1209                 prepare_read_connect(con);
1210                 break;
1211
1212         case CEPH_MSGR_TAG_READY:
1213                 if (req_feat & ~server_feat) {
1214                         pr_err("%s%lld %s protocol feature mismatch,"
1215                                " my required %llx > server's %llx, need %llx\n",
1216                                ENTITY_NAME(con->peer_name),
1217                                pr_addr(&con->peer_addr.in_addr),
1218                                req_feat, server_feat, req_feat & ~server_feat);
1219                         con->error_msg = "missing required protocol features";
1220                         fail_protocol(con);
1221                         return -1;
1222                 }
1223                 clear_bit(CONNECTING, &con->state);
1224                 con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
1225                 con->connect_seq++;
1226                 dout("process_connect got READY gseq %d cseq %d (%d)\n",
1227                      con->peer_global_seq,
1228                      le32_to_cpu(con->in_reply.connect_seq),
1229                      con->connect_seq);
1230                 WARN_ON(con->connect_seq !=
1231                         le32_to_cpu(con->in_reply.connect_seq));
1232
1233                 if (con->in_reply.flags & CEPH_MSG_CONNECT_LOSSY)
1234                         set_bit(LOSSYTX, &con->state);
1235
1236                 prepare_read_tag(con);
1237                 break;
1238
1239         case CEPH_MSGR_TAG_WAIT:
1240                 /*
1241                  * If there is a connection race (we are opening
1242                  * connections to each other), one of us may just have
1243                  * to WAIT.  This shouldn't happen if we are the
1244                  * client.
1245                  */
1246                 pr_err("process_connect peer connecting WAIT\n");
1247
1248         default:
1249                 pr_err("connect protocol error, will retry\n");
1250                 con->error_msg = "protocol error, garbage tag during connect";
1251                 return -1;
1252         }
1253         return 0;
1254 }
1255
1256
1257 /*
1258  * read (part of) an ack
1259  */
1260 static int read_partial_ack(struct ceph_connection *con)
1261 {
1262         int to = 0;
1263
1264         return read_partial(con, &to, sizeof(con->in_temp_ack),
1265                             &con->in_temp_ack);
1266 }
1267
1268
1269 /*
1270  * We can finally discard anything that's been acked.
1271  */
1272 static void process_ack(struct ceph_connection *con)
1273 {
1274         struct ceph_msg *m;
1275         u64 ack = le64_to_cpu(con->in_temp_ack);
1276         u64 seq;
1277
1278         while (!list_empty(&con->out_sent)) {
1279                 m = list_first_entry(&con->out_sent, struct ceph_msg,
1280                                      list_head);
1281                 seq = le64_to_cpu(m->hdr.seq);
1282                 if (seq > ack)
1283                         break;
1284                 dout("got ack for seq %llu type %d at %p\n", seq,
1285                      le16_to_cpu(m->hdr.type), m);
1286                 ceph_msg_remove(m);
1287         }
1288         prepare_read_tag(con);
1289 }
1290
1291
1292
1293
1294 static int read_partial_message_section(struct ceph_connection *con,
1295                                         struct kvec *section, unsigned int sec_len,
1296                                         u32 *crc)
1297 {
1298         int left;
1299         int ret;
1300
1301         BUG_ON(!section);
1302
1303         while (section->iov_len < sec_len) {
1304                 BUG_ON(section->iov_base == NULL);
1305                 left = sec_len - section->iov_len;
1306                 ret = ceph_tcp_recvmsg(con->sock, (char *)section->iov_base +
1307                                        section->iov_len, left);
1308                 if (ret <= 0)
1309                         return ret;
1310                 section->iov_len += ret;
1311                 if (section->iov_len == sec_len)
1312                         *crc = crc32c(0, section->iov_base,
1313                                       section->iov_len);
1314         }
1315
1316         return 1;
1317 }
1318
1319 static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
1320                                 struct ceph_msg_header *hdr,
1321                                 int *skip);
1322 /*
1323  * read (part of) a message.
1324  */
1325 static int read_partial_message(struct ceph_connection *con)
1326 {
1327         struct ceph_msg *m = con->in_msg;
1328         void *p;
1329         int ret;
1330         int to, left;
1331         unsigned front_len, middle_len, data_len, data_off;
1332         int datacrc = con->msgr->nocrc;
1333         int skip;
1334         u64 seq;
1335
1336         dout("read_partial_message con %p msg %p\n", con, m);
1337
1338         /* header */
1339         while (con->in_base_pos < sizeof(con->in_hdr)) {
1340                 left = sizeof(con->in_hdr) - con->in_base_pos;
1341                 ret = ceph_tcp_recvmsg(con->sock,
1342                                        (char *)&con->in_hdr + con->in_base_pos,
1343                                        left);
1344                 if (ret <= 0)
1345                         return ret;
1346                 con->in_base_pos += ret;
1347                 if (con->in_base_pos == sizeof(con->in_hdr)) {
1348                         u32 crc = crc32c(0, (void *)&con->in_hdr,
1349                                  sizeof(con->in_hdr) - sizeof(con->in_hdr.crc));
1350                         if (crc != le32_to_cpu(con->in_hdr.crc)) {
1351                                 pr_err("read_partial_message bad hdr "
1352                                        " crc %u != expected %u\n",
1353                                        crc, con->in_hdr.crc);
1354                                 return -EBADMSG;
1355                         }
1356                 }
1357         }
1358         front_len = le32_to_cpu(con->in_hdr.front_len);
1359         if (front_len > CEPH_MSG_MAX_FRONT_LEN)
1360                 return -EIO;
1361         middle_len = le32_to_cpu(con->in_hdr.middle_len);
1362         if (middle_len > CEPH_MSG_MAX_DATA_LEN)
1363                 return -EIO;
1364         data_len = le32_to_cpu(con->in_hdr.data_len);
1365         if (data_len > CEPH_MSG_MAX_DATA_LEN)
1366                 return -EIO;
1367         data_off = le16_to_cpu(con->in_hdr.data_off);
1368
1369         /* verify seq# */
1370         seq = le64_to_cpu(con->in_hdr.seq);
1371         if ((s64)seq - (s64)con->in_seq < 1) {
1372                 pr_info("skipping %s%lld %s seq %lld, expected %lld\n",
1373                         ENTITY_NAME(con->peer_name),
1374                         pr_addr(&con->peer_addr.in_addr),
1375                         seq, con->in_seq + 1);
1376                 con->in_base_pos = -front_len - middle_len - data_len -
1377                         sizeof(m->footer);
1378                 con->in_tag = CEPH_MSGR_TAG_READY;
1379                 con->in_seq++;
1380                 return 0;
1381         } else if ((s64)seq - (s64)con->in_seq > 1) {
1382                 pr_err("read_partial_message bad seq %lld expected %lld\n",
1383                        seq, con->in_seq + 1);
1384                 con->error_msg = "bad message sequence # for incoming message";
1385                 return -EBADMSG;
1386         }
1387
1388         /* allocate message? */
1389         if (!con->in_msg) {
1390                 dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
1391                      con->in_hdr.front_len, con->in_hdr.data_len);
1392                 con->in_msg = ceph_alloc_msg(con, &con->in_hdr, &skip);
1393                 if (skip) {
1394                         /* skip this message */
1395                         dout("alloc_msg said skip message\n");
1396                         con->in_base_pos = -front_len - middle_len - data_len -
1397                                 sizeof(m->footer);
1398                         con->in_tag = CEPH_MSGR_TAG_READY;
1399                         con->in_seq++;
1400                         return 0;
1401                 }
1402                 if (!con->in_msg) {
1403                         con->error_msg =
1404                                 "error allocating memory for incoming message";
1405                         return -ENOMEM;
1406                 }
1407                 m = con->in_msg;
1408                 m->front.iov_len = 0;    /* haven't read it yet */
1409                 if (m->middle)
1410                         m->middle->vec.iov_len = 0;
1411
1412                 con->in_msg_pos.page = 0;
1413                 con->in_msg_pos.page_pos = data_off & ~PAGE_MASK;
1414                 con->in_msg_pos.data_pos = 0;
1415         }
1416
1417         /* front */
1418         ret = read_partial_message_section(con, &m->front, front_len,
1419                                            &con->in_front_crc);
1420         if (ret <= 0)
1421                 return ret;
1422
1423         /* middle */
1424         if (m->middle) {
1425                 ret = read_partial_message_section(con, &m->middle->vec, middle_len,
1426                                                    &con->in_middle_crc);
1427                 if (ret <= 0)
1428                         return ret;
1429         }
1430
1431         /* (page) data */
1432         while (con->in_msg_pos.data_pos < data_len) {
1433                 left = min((int)(data_len - con->in_msg_pos.data_pos),
1434                            (int)(PAGE_SIZE - con->in_msg_pos.page_pos));
1435                 BUG_ON(m->pages == NULL);
1436                 p = kmap(m->pages[con->in_msg_pos.page]);
1437                 ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
1438                                        left);
1439                 if (ret > 0 && datacrc)
1440                         con->in_data_crc =
1441                                 crc32c(con->in_data_crc,
1442                                           p + con->in_msg_pos.page_pos, ret);
1443                 kunmap(m->pages[con->in_msg_pos.page]);
1444                 if (ret <= 0)
1445                         return ret;
1446                 con->in_msg_pos.data_pos += ret;
1447                 con->in_msg_pos.page_pos += ret;
1448                 if (con->in_msg_pos.page_pos == PAGE_SIZE) {
1449                         con->in_msg_pos.page_pos = 0;
1450                         con->in_msg_pos.page++;
1451                 }
1452         }
1453
1454         /* footer */
1455         to = sizeof(m->hdr) + sizeof(m->footer);
1456         while (con->in_base_pos < to) {
1457                 left = to - con->in_base_pos;
1458                 ret = ceph_tcp_recvmsg(con->sock, (char *)&m->footer +
1459                                        (con->in_base_pos - sizeof(m->hdr)),
1460                                        left);
1461                 if (ret <= 0)
1462                         return ret;
1463                 con->in_base_pos += ret;
1464         }
1465         dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
1466              m, front_len, m->footer.front_crc, middle_len,
1467              m->footer.middle_crc, data_len, m->footer.data_crc);
1468
1469         /* crc ok? */
1470         if (con->in_front_crc != le32_to_cpu(m->footer.front_crc)) {
1471                 pr_err("read_partial_message %p front crc %u != exp. %u\n",
1472                        m, con->in_front_crc, m->footer.front_crc);
1473                 return -EBADMSG;
1474         }
1475         if (con->in_middle_crc != le32_to_cpu(m->footer.middle_crc)) {
1476                 pr_err("read_partial_message %p middle crc %u != exp %u\n",
1477                        m, con->in_middle_crc, m->footer.middle_crc);
1478                 return -EBADMSG;
1479         }
1480         if (datacrc &&
1481             (m->footer.flags & CEPH_MSG_FOOTER_NOCRC) == 0 &&
1482             con->in_data_crc != le32_to_cpu(m->footer.data_crc)) {
1483                 pr_err("read_partial_message %p data crc %u != exp. %u\n", m,
1484                        con->in_data_crc, le32_to_cpu(m->footer.data_crc));
1485                 return -EBADMSG;
1486         }
1487
1488         return 1; /* done! */
1489 }
1490
1491 /*
1492  * Process message.  This happens in the worker thread.  The callback should
1493  * be careful not to do anything that waits on other incoming messages or it
1494  * may deadlock.
1495  */
1496 static void process_message(struct ceph_connection *con)
1497 {
1498         struct ceph_msg *msg;
1499
1500         msg = con->in_msg;
1501         con->in_msg = NULL;
1502
1503         /* if first message, set peer_name */
1504         if (con->peer_name.type == 0)
1505                 con->peer_name = msg->hdr.src;
1506
1507         con->in_seq++;
1508         mutex_unlock(&con->mutex);
1509
1510         dout("===== %p %llu from %s%lld %d=%s len %d+%d (%u %u %u) =====\n",
1511              msg, le64_to_cpu(msg->hdr.seq),
1512              ENTITY_NAME(msg->hdr.src),
1513              le16_to_cpu(msg->hdr.type),
1514              ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
1515              le32_to_cpu(msg->hdr.front_len),
1516              le32_to_cpu(msg->hdr.data_len),
1517              con->in_front_crc, con->in_middle_crc, con->in_data_crc);
1518         con->ops->dispatch(con, msg);
1519
1520         mutex_lock(&con->mutex);
1521         prepare_read_tag(con);
1522 }
1523
1524
1525 /*
1526  * Write something to the socket.  Called in a worker thread when the
1527  * socket appears to be writeable and we have something ready to send.
1528  */
1529 static int try_write(struct ceph_connection *con)
1530 {
1531         struct ceph_messenger *msgr = con->msgr;
1532         int ret = 1;
1533
1534         dout("try_write start %p state %lu nref %d\n", con, con->state,
1535              atomic_read(&con->nref));
1536
1537 more:
1538         dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
1539
1540         /* open the socket first? */
1541         if (con->sock == NULL) {
1542                 /*
1543                  * if we were STANDBY and are reconnecting _this_
1544                  * connection, bump connect_seq now.  Always bump
1545                  * global_seq.
1546                  */
1547                 if (test_and_clear_bit(STANDBY, &con->state))
1548                         con->connect_seq++;
1549
1550                 prepare_write_banner(msgr, con);
1551                 prepare_write_connect(msgr, con, 1);
1552                 prepare_read_banner(con);
1553                 set_bit(CONNECTING, &con->state);
1554                 clear_bit(NEGOTIATING, &con->state);
1555
1556                 BUG_ON(con->in_msg);
1557                 con->in_tag = CEPH_MSGR_TAG_READY;
1558                 dout("try_write initiating connect on %p new state %lu\n",
1559                      con, con->state);
1560                 con->sock = ceph_tcp_connect(con);
1561                 if (IS_ERR(con->sock)) {
1562                         con->sock = NULL;
1563                         con->error_msg = "connect error";
1564                         ret = -1;
1565                         goto out;
1566                 }
1567         }
1568
1569 more_kvec:
1570         /* kvec data queued? */
1571         if (con->out_skip) {
1572                 ret = write_partial_skip(con);
1573                 if (ret <= 0)
1574                         goto done;
1575                 if (ret < 0) {
1576                         dout("try_write write_partial_skip err %d\n", ret);
1577                         goto done;
1578                 }
1579         }
1580         if (con->out_kvec_left) {
1581                 ret = write_partial_kvec(con);
1582                 if (ret <= 0)
1583                         goto done;
1584         }
1585
1586         /* msg pages? */
1587         if (con->out_msg) {
1588                 if (con->out_msg_done) {
1589                         ceph_msg_put(con->out_msg);
1590                         con->out_msg = NULL;   /* we're done with this one */
1591                         goto do_next;
1592                 }
1593
1594                 ret = write_partial_msg_pages(con);
1595                 if (ret == 1)
1596                         goto more_kvec;  /* we need to send the footer, too! */
1597                 if (ret == 0)
1598                         goto done;
1599                 if (ret < 0) {
1600                         dout("try_write write_partial_msg_pages err %d\n",
1601                              ret);
1602                         goto done;
1603                 }
1604         }
1605
1606 do_next:
1607         if (!test_bit(CONNECTING, &con->state)) {
1608                 /* is anything else pending? */
1609                 if (!list_empty(&con->out_queue)) {
1610                         prepare_write_message(con);
1611                         goto more;
1612                 }
1613                 if (con->in_seq > con->in_seq_acked) {
1614                         prepare_write_ack(con);
1615                         goto more;
1616                 }
1617                 if (test_and_clear_bit(KEEPALIVE_PENDING, &con->state)) {
1618                         prepare_write_keepalive(con);
1619                         goto more;
1620                 }
1621         }
1622
1623         /* Nothing to do! */
1624         clear_bit(WRITE_PENDING, &con->state);
1625         dout("try_write nothing else to write.\n");
1626 done:
1627         ret = 0;
1628 out:
1629         dout("try_write done on %p\n", con);
1630         return ret;
1631 }
1632
1633
1634
1635 /*
1636  * Read what we can from the socket.
1637  */
1638 static int try_read(struct ceph_connection *con)
1639 {
1640         int ret = -1;
1641
1642         if (!con->sock)
1643                 return 0;
1644
1645         if (test_bit(STANDBY, &con->state))
1646                 return 0;
1647
1648         dout("try_read start on %p\n", con);
1649
1650 more:
1651         dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,
1652              con->in_base_pos);
1653         if (test_bit(CONNECTING, &con->state)) {
1654                 if (!test_bit(NEGOTIATING, &con->state)) {
1655                         dout("try_read connecting\n");
1656                         ret = read_partial_banner(con);
1657                         if (ret <= 0)
1658                                 goto done;
1659                         if (process_banner(con) < 0) {
1660                                 ret = -1;
1661                                 goto out;
1662                         }
1663                 }
1664                 ret = read_partial_connect(con);
1665                 if (ret <= 0)
1666                         goto done;
1667                 if (process_connect(con) < 0) {
1668                         ret = -1;
1669                         goto out;
1670                 }
1671                 goto more;
1672         }
1673
1674         if (con->in_base_pos < 0) {
1675                 /*
1676                  * skipping + discarding content.
1677                  *
1678                  * FIXME: there must be a better way to do this!
1679                  */
1680                 static char buf[1024];
1681                 int skip = min(1024, -con->in_base_pos);
1682                 dout("skipping %d / %d bytes\n", skip, -con->in_base_pos);
1683                 ret = ceph_tcp_recvmsg(con->sock, buf, skip);
1684                 if (ret <= 0)
1685                         goto done;
1686                 con->in_base_pos += ret;
1687                 if (con->in_base_pos)
1688                         goto more;
1689         }
1690         if (con->in_tag == CEPH_MSGR_TAG_READY) {
1691                 /*
1692                  * what's next?
1693                  */
1694                 ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
1695                 if (ret <= 0)
1696                         goto done;
1697                 dout("try_read got tag %d\n", (int)con->in_tag);
1698                 switch (con->in_tag) {
1699                 case CEPH_MSGR_TAG_MSG:
1700                         prepare_read_message(con);
1701                         break;
1702                 case CEPH_MSGR_TAG_ACK:
1703                         prepare_read_ack(con);
1704                         break;
1705                 case CEPH_MSGR_TAG_CLOSE:
1706                         set_bit(CLOSED, &con->state);   /* fixme */
1707                         goto done;
1708                 default:
1709                         goto bad_tag;
1710                 }
1711         }
1712         if (con->in_tag == CEPH_MSGR_TAG_MSG) {
1713                 ret = read_partial_message(con);
1714                 if (ret <= 0) {
1715                         switch (ret) {
1716                         case -EBADMSG:
1717                                 con->error_msg = "bad crc";
1718                                 ret = -EIO;
1719                                 goto out;
1720                         case -EIO:
1721                                 con->error_msg = "io error";
1722                                 goto out;
1723                         default:
1724                                 goto done;
1725                         }
1726                 }
1727                 if (con->in_tag == CEPH_MSGR_TAG_READY)
1728                         goto more;
1729                 process_message(con);
1730                 goto more;
1731         }
1732         if (con->in_tag == CEPH_MSGR_TAG_ACK) {
1733                 ret = read_partial_ack(con);
1734                 if (ret <= 0)
1735                         goto done;
1736                 process_ack(con);
1737                 goto more;
1738         }
1739
1740 done:
1741         ret = 0;
1742 out:
1743         dout("try_read done on %p\n", con);
1744         return ret;
1745
1746 bad_tag:
1747         pr_err("try_read bad con->in_tag = %d\n", (int)con->in_tag);
1748         con->error_msg = "protocol error, garbage tag";
1749         ret = -1;
1750         goto out;
1751 }
1752
1753
1754 /*
1755  * Atomically queue work on a connection.  Bump @con reference to
1756  * avoid races with connection teardown.
1757  *
1758  * There is some trickery going on with QUEUED and BUSY because we
1759  * only want a _single_ thread operating on each connection at any
1760  * point in time, but we want to use all available CPUs.
1761  *
1762  * The worker thread only proceeds if it can atomically set BUSY.  It
1763  * clears QUEUED and does it's thing.  When it thinks it's done, it
1764  * clears BUSY, then rechecks QUEUED.. if it's set again, it loops
1765  * (tries again to set BUSY).
1766  *
1767  * To queue work, we first set QUEUED, _then_ if BUSY isn't set, we
1768  * try to queue work.  If that fails (work is already queued, or BUSY)
1769  * we give up (work also already being done or is queued) but leave QUEUED
1770  * set so that the worker thread will loop if necessary.
1771  */
1772 static void queue_con(struct ceph_connection *con)
1773 {
1774         if (test_bit(DEAD, &con->state)) {
1775                 dout("queue_con %p ignoring: DEAD\n",
1776                      con);
1777                 return;
1778         }
1779
1780         if (!con->ops->get(con)) {
1781                 dout("queue_con %p ref count 0\n", con);
1782                 return;
1783         }
1784
1785         set_bit(QUEUED, &con->state);
1786         if (test_bit(BUSY, &con->state)) {
1787                 dout("queue_con %p - already BUSY\n", con);
1788                 con->ops->put(con);
1789         } else if (!queue_work(ceph_msgr_wq, &con->work.work)) {
1790                 dout("queue_con %p - already queued\n", con);
1791                 con->ops->put(con);
1792         } else {
1793                 dout("queue_con %p\n", con);
1794         }
1795 }
1796
1797 /*
1798  * Do some work on a connection.  Drop a connection ref when we're done.
1799  */
1800 static void con_work(struct work_struct *work)
1801 {
1802         struct ceph_connection *con = container_of(work, struct ceph_connection,
1803                                                    work.work);
1804         int backoff = 0;
1805
1806 more:
1807         if (test_and_set_bit(BUSY, &con->state) != 0) {
1808                 dout("con_work %p BUSY already set\n", con);
1809                 goto out;
1810         }
1811         dout("con_work %p start, clearing QUEUED\n", con);
1812         clear_bit(QUEUED, &con->state);
1813
1814         mutex_lock(&con->mutex);
1815
1816         if (test_bit(CLOSED, &con->state)) { /* e.g. if we are replaced */
1817                 dout("con_work CLOSED\n");
1818                 con_close_socket(con);
1819                 goto done;
1820         }
1821         if (test_and_clear_bit(OPENING, &con->state)) {
1822                 /* reopen w/ new peer */
1823                 dout("con_work OPENING\n");
1824                 con_close_socket(con);
1825         }
1826
1827         if (test_and_clear_bit(SOCK_CLOSED, &con->state) ||
1828             try_read(con) < 0 ||
1829             try_write(con) < 0) {
1830                 mutex_unlock(&con->mutex);
1831                 backoff = 1;
1832                 ceph_fault(con);     /* error/fault path */
1833                 goto done_unlocked;
1834         }
1835
1836 done:
1837         mutex_unlock(&con->mutex);
1838
1839 done_unlocked:
1840         clear_bit(BUSY, &con->state);
1841         dout("con->state=%lu\n", con->state);
1842         if (test_bit(QUEUED, &con->state)) {
1843                 if (!backoff || test_bit(OPENING, &con->state)) {
1844                         dout("con_work %p QUEUED reset, looping\n", con);
1845                         goto more;
1846                 }
1847                 dout("con_work %p QUEUED reset, but just faulted\n", con);
1848                 clear_bit(QUEUED, &con->state);
1849         }
1850         dout("con_work %p done\n", con);
1851
1852 out:
1853         con->ops->put(con);
1854 }
1855
1856
1857 /*
1858  * Generic error/fault handler.  A retry mechanism is used with
1859  * exponential backoff
1860  */
1861 static void ceph_fault(struct ceph_connection *con)
1862 {
1863         pr_err("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
1864                pr_addr(&con->peer_addr.in_addr), con->error_msg);
1865         dout("fault %p state %lu to peer %s\n",
1866              con, con->state, pr_addr(&con->peer_addr.in_addr));
1867
1868         if (test_bit(LOSSYTX, &con->state)) {
1869                 dout("fault on LOSSYTX channel\n");
1870                 goto out;
1871         }
1872
1873         mutex_lock(&con->mutex);
1874         if (test_bit(CLOSED, &con->state))
1875                 goto out_unlock;
1876
1877         con_close_socket(con);
1878
1879         if (con->in_msg) {
1880                 ceph_msg_put(con->in_msg);
1881                 con->in_msg = NULL;
1882         }
1883
1884         /* Requeue anything that hasn't been acked */
1885         list_splice_init(&con->out_sent, &con->out_queue);
1886
1887         /* If there are no messages in the queue, place the connection
1888          * in a STANDBY state (i.e., don't try to reconnect just yet). */
1889         if (list_empty(&con->out_queue) && !con->out_keepalive_pending) {
1890                 dout("fault setting STANDBY\n");
1891                 set_bit(STANDBY, &con->state);
1892         } else {
1893                 /* retry after a delay. */
1894                 if (con->delay == 0)
1895                         con->delay = BASE_DELAY_INTERVAL;
1896                 else if (con->delay < MAX_DELAY_INTERVAL)
1897                         con->delay *= 2;
1898                 dout("fault queueing %p delay %lu\n", con, con->delay);
1899                 con->ops->get(con);
1900                 if (queue_delayed_work(ceph_msgr_wq, &con->work,
1901                                        round_jiffies_relative(con->delay)) == 0)
1902                         con->ops->put(con);
1903         }
1904
1905 out_unlock:
1906         mutex_unlock(&con->mutex);
1907 out:
1908         /*
1909          * in case we faulted due to authentication, invalidate our
1910          * current tickets so that we can get new ones.
1911          */
1912         if (con->auth_retry && con->ops->invalidate_authorizer) {
1913                 dout("calling invalidate_authorizer()\n");
1914                 con->ops->invalidate_authorizer(con);
1915         }
1916
1917         if (con->ops->fault)
1918                 con->ops->fault(con);
1919 }
1920
1921
1922
1923 /*
1924  * create a new messenger instance
1925  */
1926 struct ceph_messenger *ceph_messenger_create(struct ceph_entity_addr *myaddr)
1927 {
1928         struct ceph_messenger *msgr;
1929
1930         msgr = kzalloc(sizeof(*msgr), GFP_KERNEL);
1931         if (msgr == NULL)
1932                 return ERR_PTR(-ENOMEM);
1933
1934         spin_lock_init(&msgr->global_seq_lock);
1935
1936         /* the zero page is needed if a request is "canceled" while the message
1937          * is being written over the socket */
1938         msgr->zero_page = __page_cache_alloc(GFP_KERNEL | __GFP_ZERO);
1939         if (!msgr->zero_page) {
1940                 kfree(msgr);
1941                 return ERR_PTR(-ENOMEM);
1942         }
1943         kmap(msgr->zero_page);
1944
1945         if (myaddr)
1946                 msgr->inst.addr = *myaddr;
1947
1948         /* select a random nonce */
1949         msgr->inst.addr.type = 0;
1950         get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
1951         encode_my_addr(msgr);
1952
1953         dout("messenger_create %p\n", msgr);
1954         return msgr;
1955 }
1956
1957 void ceph_messenger_destroy(struct ceph_messenger *msgr)
1958 {
1959         dout("destroy %p\n", msgr);
1960         kunmap(msgr->zero_page);
1961         __free_page(msgr->zero_page);
1962         kfree(msgr);
1963         dout("destroyed messenger %p\n", msgr);
1964 }
1965
1966 /*
1967  * Queue up an outgoing message on the given connection.
1968  */
1969 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
1970 {
1971         if (test_bit(CLOSED, &con->state)) {
1972                 dout("con_send %p closed, dropping %p\n", con, msg);
1973                 ceph_msg_put(msg);
1974                 return;
1975         }
1976
1977         /* set src+dst */
1978         msg->hdr.src = con->msgr->inst.name;
1979
1980         BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
1981
1982         msg->needs_out_seq = true;
1983
1984         /* queue */
1985         mutex_lock(&con->mutex);
1986         BUG_ON(!list_empty(&msg->list_head));
1987         list_add_tail(&msg->list_head, &con->out_queue);
1988         dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
1989              ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
1990              ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
1991              le32_to_cpu(msg->hdr.front_len),
1992              le32_to_cpu(msg->hdr.middle_len),
1993              le32_to_cpu(msg->hdr.data_len));
1994         mutex_unlock(&con->mutex);
1995
1996         /* if there wasn't anything waiting to send before, queue
1997          * new work */
1998         if (test_and_set_bit(WRITE_PENDING, &con->state) == 0)
1999                 queue_con(con);
2000 }
2001
2002 /*
2003  * Revoke a message that was previously queued for send
2004  */
2005 void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg)
2006 {
2007         mutex_lock(&con->mutex);
2008         if (!list_empty(&msg->list_head)) {
2009                 dout("con_revoke %p msg %p\n", con, msg);
2010                 list_del_init(&msg->list_head);
2011                 ceph_msg_put(msg);
2012                 msg->hdr.seq = 0;
2013                 if (con->out_msg == msg) {
2014                         ceph_msg_put(con->out_msg);
2015                         con->out_msg = NULL;
2016                 }
2017                 if (con->out_kvec_is_msg) {
2018                         con->out_skip = con->out_kvec_bytes;
2019                         con->out_kvec_is_msg = false;
2020                 }
2021         } else {
2022                 dout("con_revoke %p msg %p - not queued (sent?)\n", con, msg);
2023         }
2024         mutex_unlock(&con->mutex);
2025 }
2026
2027 /*
2028  * Revoke a message that we may be reading data into
2029  */
2030 void ceph_con_revoke_message(struct ceph_connection *con, struct ceph_msg *msg)
2031 {
2032         mutex_lock(&con->mutex);
2033         if (con->in_msg && con->in_msg == msg) {
2034                 unsigned front_len = le32_to_cpu(con->in_hdr.front_len);
2035                 unsigned middle_len = le32_to_cpu(con->in_hdr.middle_len);
2036                 unsigned data_len = le32_to_cpu(con->in_hdr.data_len);
2037
2038                 /* skip rest of message */
2039                 dout("con_revoke_pages %p msg %p revoked\n", con, msg);
2040                         con->in_base_pos = con->in_base_pos -
2041                                 sizeof(struct ceph_msg_header) -
2042                                 front_len -
2043                                 middle_len -
2044                                 data_len -
2045                                 sizeof(struct ceph_msg_footer);
2046                 ceph_msg_put(con->in_msg);
2047                 con->in_msg = NULL;
2048                 con->in_tag = CEPH_MSGR_TAG_READY;
2049                 con->in_seq++;
2050         } else {
2051                 dout("con_revoke_pages %p msg %p pages %p no-op\n",
2052                      con, con->in_msg, msg);
2053         }
2054         mutex_unlock(&con->mutex);
2055 }
2056
2057 /*
2058  * Queue a keepalive byte to ensure the tcp connection is alive.
2059  */
2060 void ceph_con_keepalive(struct ceph_connection *con)
2061 {
2062         if (test_and_set_bit(KEEPALIVE_PENDING, &con->state) == 0 &&
2063             test_and_set_bit(WRITE_PENDING, &con->state) == 0)
2064                 queue_con(con);
2065 }
2066
2067
2068 /*
2069  * construct a new message with given type, size
2070  * the new msg has a ref count of 1.
2071  */
2072 struct ceph_msg *ceph_msg_new(int type, int front_len)
2073 {
2074         struct ceph_msg *m;
2075
2076         m = kmalloc(sizeof(*m), GFP_NOFS);
2077         if (m == NULL)
2078                 goto out;
2079         kref_init(&m->kref);
2080         INIT_LIST_HEAD(&m->list_head);
2081
2082         m->hdr.tid = 0;
2083         m->hdr.type = cpu_to_le16(type);
2084         m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
2085         m->hdr.version = 0;
2086         m->hdr.front_len = cpu_to_le32(front_len);
2087         m->hdr.middle_len = 0;
2088         m->hdr.data_len = 0;
2089         m->hdr.data_off = 0;
2090         m->hdr.reserved = 0;
2091         m->footer.front_crc = 0;
2092         m->footer.middle_crc = 0;
2093         m->footer.data_crc = 0;
2094         m->footer.flags = 0;
2095         m->front_max = front_len;
2096         m->front_is_vmalloc = false;
2097         m->more_to_follow = false;
2098         m->pool = NULL;
2099
2100         /* front */
2101         if (front_len) {
2102                 if (front_len > PAGE_CACHE_SIZE) {
2103                         m->front.iov_base = __vmalloc(front_len, GFP_NOFS,
2104                                                       PAGE_KERNEL);
2105                         m->front_is_vmalloc = true;
2106                 } else {
2107                         m->front.iov_base = kmalloc(front_len, GFP_NOFS);
2108                 }
2109                 if (m->front.iov_base == NULL) {
2110                         pr_err("msg_new can't allocate %d bytes\n",
2111                              front_len);
2112                         goto out2;
2113                 }
2114         } else {
2115                 m->front.iov_base = NULL;
2116         }
2117         m->front.iov_len = front_len;
2118
2119         /* middle */
2120         m->middle = NULL;
2121
2122         /* data */
2123         m->nr_pages = 0;
2124         m->pages = NULL;
2125         m->pagelist = NULL;
2126
2127         dout("ceph_msg_new %p front %d\n", m, front_len);
2128         return m;
2129
2130 out2:
2131         ceph_msg_put(m);
2132 out:
2133         pr_err("msg_new can't create type %d front %d\n", type, front_len);
2134         return NULL;
2135 }
2136
2137 /*
2138  * Allocate "middle" portion of a message, if it is needed and wasn't
2139  * allocated by alloc_msg.  This allows us to read a small fixed-size
2140  * per-type header in the front and then gracefully fail (i.e.,
2141  * propagate the error to the caller based on info in the front) when
2142  * the middle is too large.
2143  */
2144 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
2145 {
2146         int type = le16_to_cpu(msg->hdr.type);
2147         int middle_len = le32_to_cpu(msg->hdr.middle_len);
2148
2149         dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
2150              ceph_msg_type_name(type), middle_len);
2151         BUG_ON(!middle_len);
2152         BUG_ON(msg->middle);
2153
2154         msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
2155         if (!msg->middle)
2156                 return -ENOMEM;
2157         return 0;
2158 }
2159
2160 /*
2161  * Generic message allocator, for incoming messages.
2162  */
2163 static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
2164                                 struct ceph_msg_header *hdr,
2165                                 int *skip)
2166 {
2167         int type = le16_to_cpu(hdr->type);
2168         int front_len = le32_to_cpu(hdr->front_len);
2169         int middle_len = le32_to_cpu(hdr->middle_len);
2170         struct ceph_msg *msg = NULL;
2171         int ret;
2172
2173         if (con->ops->alloc_msg) {
2174                 mutex_unlock(&con->mutex);
2175                 msg = con->ops->alloc_msg(con, hdr, skip);
2176                 mutex_lock(&con->mutex);
2177                 if (!msg || *skip)
2178                         return NULL;
2179         }
2180         if (!msg) {
2181                 *skip = 0;
2182                 msg = ceph_msg_new(type, front_len);
2183                 if (!msg) {
2184                         pr_err("unable to allocate msg type %d len %d\n",
2185                                type, front_len);
2186                         return NULL;
2187                 }
2188         }
2189         memcpy(&msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
2190
2191         if (middle_len && !msg->middle) {
2192                 ret = ceph_alloc_middle(con, msg);
2193                 if (ret < 0) {
2194                         ceph_msg_put(msg);
2195                         return NULL;
2196                 }
2197         }
2198
2199         return msg;
2200 }
2201
2202
2203 /*
2204  * Free a generically kmalloc'd message.
2205  */
2206 void ceph_msg_kfree(struct ceph_msg *m)
2207 {
2208         dout("msg_kfree %p\n", m);
2209         if (m->front_is_vmalloc)
2210                 vfree(m->front.iov_base);
2211         else
2212                 kfree(m->front.iov_base);
2213         kfree(m);
2214 }
2215
2216 /*
2217  * Drop a msg ref.  Destroy as needed.
2218  */
2219 void ceph_msg_last_put(struct kref *kref)
2220 {
2221         struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
2222
2223         dout("ceph_msg_put last one on %p\n", m);
2224         WARN_ON(!list_empty(&m->list_head));
2225
2226         /* drop middle, data, if any */
2227         if (m->middle) {
2228                 ceph_buffer_put(m->middle);
2229                 m->middle = NULL;
2230         }
2231         m->nr_pages = 0;
2232         m->pages = NULL;
2233
2234         if (m->pagelist) {
2235                 ceph_pagelist_release(m->pagelist);
2236                 kfree(m->pagelist);
2237                 m->pagelist = NULL;
2238         }
2239
2240         if (m->pool)
2241                 ceph_msgpool_put(m->pool, m);
2242         else
2243                 ceph_msg_kfree(m);
2244 }
2245
2246 void ceph_msg_dump(struct ceph_msg *msg)
2247 {
2248         pr_debug("msg_dump %p (front_max %d nr_pages %d)\n", msg,
2249                  msg->front_max, msg->nr_pages);
2250         print_hex_dump(KERN_DEBUG, "header: ",
2251                        DUMP_PREFIX_OFFSET, 16, 1,
2252                        &msg->hdr, sizeof(msg->hdr), true);
2253         print_hex_dump(KERN_DEBUG, " front: ",
2254                        DUMP_PREFIX_OFFSET, 16, 1,
2255                        msg->front.iov_base, msg->front.iov_len, true);
2256         if (msg->middle)
2257                 print_hex_dump(KERN_DEBUG, "middle: ",
2258                                DUMP_PREFIX_OFFSET, 16, 1,
2259                                msg->middle->vec.iov_base,
2260                                msg->middle->vec.iov_len, true);
2261         print_hex_dump(KERN_DEBUG, "footer: ",
2262                        DUMP_PREFIX_OFFSET, 16, 1,
2263                        &msg->footer, sizeof(msg->footer), true);
2264 }