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/socket.h>
  10 #include <linux/string.h>
  11 #include <net/tcp.h>
  12
  13 #include "super.h"
  14 #include "messenger.h"
  15 #include "decode.h"
  16 #include "pagelist.h"
  17
  18 /*
  19  * Ceph uses the messenger to exchange ceph_msg messages with other
  20  * hosts in the system.  The messenger provides ordered and reliable
  21  * delivery.  We tolerate TCP disconnects by reconnecting (with
  22  * exponential backoff) in the case of a fault (disconnection, bad
  23  * crc, protocol error).  Acks allow sent messages to be discarded by
  24  * the sender.
  25  */
  26
  27 /* static tag bytes (protocol control messages) */
  28 static char tag_msg = CEPH_MSGR_TAG_MSG;
  29 static char tag_ack = CEPH_MSGR_TAG_ACK;
  30 static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
  31
  32
  33 static void queue_con(struct ceph_connection *con);
  34 static void con_work(struct work_struct *);
  35 static void ceph_fault(struct ceph_connection *con);
  36
  37 const char *ceph_name_type_str(int t)
  38 {
  39         switch (t) {
  40         case CEPH_ENTITY_TYPE_MON: return "mon";
  41         case CEPH_ENTITY_TYPE_MDS: return "mds";
  42         case CEPH_ENTITY_TYPE_OSD: return "osd";
  43         case CEPH_ENTITY_TYPE_CLIENT: return "client";
  44         case CEPH_ENTITY_TYPE_ADMIN: return "admin";
  45         default: return "???";
  46         }
  47 }
  48
  49 /*
  50  * nicely render a sockaddr as a string.
  51  */
  52 #define MAX_ADDR_STR 20
  53 static char addr_str[MAX_ADDR_STR][40];
  54 static DEFINE_SPINLOCK(addr_str_lock);
  55 static int last_addr_str;
  56
  57 const char *pr_addr(const struct sockaddr_storage *ss)
  58 {
  59         int i;
  60         char *s;
  61         struct sockaddr_in *in4 = (void *)ss;
  62         unsigned char *quad = (void *)&in4->sin_addr.s_addr;
  63         struct sockaddr_in6 *in6 = (void *)ss;
  64
  65         spin_lock(&addr_str_lock);
  66         i = last_addr_str++;
  67         if (last_addr_str == MAX_ADDR_STR)
  68                 last_addr_str = 0;
  69         spin_unlock(&addr_str_lock);
  70         s = addr_str[i];
  71
  72         switch (ss->ss_family) {
  73         case AF_INET:
  74                 sprintf(s, "%u.%u.%u.%u:%u",
  75                         (unsigned int)quad[0],
  76                         (unsigned int)quad[1],
  77                         (unsigned int)quad[2],
  78                         (unsigned int)quad[3],
  79                         (unsigned int)ntohs(in4->sin_port));
  80                 break;
  81
  82         case AF_INET6:
  83                 sprintf(s, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%u",
  84                         in6->sin6_addr.s6_addr16[0],
  85                         in6->sin6_addr.s6_addr16[1],
  86                         in6->sin6_addr.s6_addr16[2],
  87                         in6->sin6_addr.s6_addr16[3],
  88                         in6->sin6_addr.s6_addr16[4],
  89                         in6->sin6_addr.s6_addr16[5],
  90                         in6->sin6_addr.s6_addr16[6],
  91                         in6->sin6_addr.s6_addr16[7],
  92                         (unsigned int)ntohs(in6->sin6_port));
  93                 break;
  94
  95         default:
  96                 sprintf(s, "(unknown sockaddr family %d)", (int)ss->ss_family);
  97         }
  98
  99         return s;
 100 }
 101
 102 static void encode_my_addr(struct ceph_messenger *msgr)
 103 {
 104         memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
 105         ceph_encode_addr(&msgr->my_enc_addr);
 106 }
 107
 108 /*
 109  * work queue for all reading and writing to/from the socket.
 110  */
 111 struct workqueue_struct *ceph_msgr_wq;
 112
 113 int __init ceph_msgr_init(void)
 114 {
 115         ceph_msgr_wq = create_workqueue("ceph-msgr");
 116         if (IS_ERR(ceph_msgr_wq)) {
 117                 int ret = PTR_ERR(ceph_msgr_wq);
 118                 pr_err("msgr_init failed to create workqueue: %d\n", ret);
 119                 ceph_msgr_wq = NULL;
 120                 return ret;
 121         }
 122         return 0;
 123 }
 124
 125 void ceph_msgr_exit(void)
 126 {
 127         destroy_workqueue(ceph_msgr_wq);
 128 }
 129
 130 /*
 131  * socket callback functions
 132  */
 133
 134 /* data available on socket, or listen socket received a connect */
 135 static void ceph_data_ready(struct sock *sk, int count_unused)
 136 {
 137         struct ceph_connection *con =
 138                 (struct ceph_connection *)sk->sk_user_data;
 139         if (sk->sk_state != TCP_CLOSE_WAIT) {
 140                 dout("ceph_data_ready on %p state = %lu, queueing work\n",
 141                      con, con->state);
 142                 queue_con(con);
 143         }
 144 }
 145
 146 /* socket has buffer space for writing */
 147 static void ceph_write_space(struct sock *sk)
 148 {
 149         struct ceph_connection *con =
 150                 (struct ceph_connection *)sk->sk_user_data;
 151
 152         /* only queue to workqueue if there is data we want to write. */
 153         if (test_bit(WRITE_PENDING, &con->state)) {
 154                 dout("ceph_write_space %p queueing write work\n", con);
 155                 queue_con(con);
 156         } else {
 157                 dout("ceph_write_space %p nothing to write\n", con);
 158         }
 159
 160         /* since we have our own write_space, clear the SOCK_NOSPACE flag */
 161         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 162 }
 163
 164 /* socket's state has changed */
 165 static void ceph_state_change(struct sock *sk)
 166 {
 167         struct ceph_connection *con =
 168                 (struct ceph_connection *)sk->sk_user_data;
 169
 170         dout("ceph_state_change %p state = %lu sk_state = %u\n",
 171              con, con->state, sk->sk_state);
 172
 173         if (test_bit(CLOSED, &con->state))
 174                 return;
 175
 176         switch (sk->sk_state) {
 177         case TCP_CLOSE:
 178                 dout("ceph_state_change TCP_CLOSE\n");
 179         case TCP_CLOSE_WAIT:
 180                 dout("ceph_state_change TCP_CLOSE_WAIT\n");
 181                 if (test_and_set_bit(SOCK_CLOSED, &con->state) == 0) {
 182                         if (test_bit(CONNECTING, &con->state))
 183                                 con->error_msg = "connection failed";
 184                         else
 185                                 con->error_msg = "socket closed";
 186                         queue_con(con);
 187                 }
 188                 break;
 189         case TCP_ESTABLISHED:
 190                 dout("ceph_state_change TCP_ESTABLISHED\n");
 191                 queue_con(con);
 192                 break;
 193         }
 194 }
 195
 196 /*
 197  * set up socket callbacks
 198  */
 199 static void set_sock_callbacks(struct socket *sock,
 200                                struct ceph_connection *con)
 201 {
 202         struct sock *sk = sock->sk;
 203         sk->sk_user_data = (void *)con;
 204         sk->sk_data_ready = ceph_data_ready;
 205         sk->sk_write_space = ceph_write_space;
 206         sk->sk_state_change = ceph_state_change;
 207 }
 208
 209
 210 /*
 211  * socket helpers
 212  */
 213
 214 /*
 215  * initiate connection to a remote socket.
 216  */
 217 static struct socket *ceph_tcp_connect(struct ceph_connection *con)
 218 {
 219         struct sockaddr *paddr = (struct sockaddr *)&con->peer_addr.in_addr;
 220         struct socket *sock;
 221         int ret;
 222
 223         BUG_ON(con->sock);
 224         ret = sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
 225         if (ret)
 226                 return ERR_PTR(ret);
 227         con->sock = sock;
 228         sock->sk->sk_allocation = GFP_NOFS;
 229
 230         set_sock_callbacks(sock, con);
 231
 232         dout("connect %s\n", pr_addr(&con->peer_addr.in_addr));
 233
 234         ret = sock->ops->connect(sock, paddr, sizeof(*paddr), O_NONBLOCK);
 235         if (ret == -EINPROGRESS) {
 236                 dout("connect %s EINPROGRESS sk_state = %u\n",
 237                      pr_addr(&con->peer_addr.in_addr),
 238                      sock->sk->sk_state);
 239                 ret = 0;
 240         }
 241         if (ret < 0) {
 242                 pr_err("connect %s error %d\n",
 243                        pr_addr(&con->peer_addr.in_addr), ret);
 244                 sock_release(sock);
 245                 con->sock = NULL;
 246                 con->error_msg = "connect error";
 247         }
 248
 249         if (ret < 0)
 250                 return ERR_PTR(ret);
 251         return sock;
 252 }
 253
 254 static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
 255 {
 256         struct kvec iov = {buf, len};
 257         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 258
 259         return kernel_recvmsg(sock, &msg, &iov, 1, len, msg.msg_flags);
 260 }
 261
 262 /*
 263  * write something.  @more is true if caller will be sending more data
 264  * shortly.
 265  */
 266 static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
 267                      size_t kvlen, size_t len, int more)
 268 {
 269         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
 270
 271         if (more)
 272                 msg.msg_flags |= MSG_MORE;
 273         else
 274                 msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
 275
 276         return kernel_sendmsg(sock, &msg, iov, kvlen, len);
 277 }
 278
 279
 280 /*
 281  * Shutdown/close the socket for the given connection.
 282  */
 283 static int con_close_socket(struct ceph_connection *con)
 284 {
 285         int rc;
 286
 287         dout("con_close_socket on %p sock %p\n", con, con->sock);
 288         if (!con->sock)
 289                 return 0;
 290         set_bit(SOCK_CLOSED, &con->state);
 291         rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
 292         sock_release(con->sock);
 293         con->sock = NULL;
 294         clear_bit(SOCK_CLOSED, &con->state);
 295         return rc;
 296 }
 297
 298 /*
 299  * Reset a connection.  Discard all incoming and outgoing messages
 300  * and clear *_seq state.
 301  */
 302 static void ceph_msg_remove(struct ceph_msg *msg)
 303 {
 304         list_del_init(&msg->list_head);
 305         ceph_msg_put(msg);
 306 }
 307 static void ceph_msg_remove_list(struct list_head *head)
 308 {
 309         while (!list_empty(head)) {
 310                 struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
 311                                                         list_head);
 312                 ceph_msg_remove(msg);
 313         }
 314 }
 315
 316 static void reset_connection(struct ceph_connection *con)
 317 {
 318         /* reset connection, out_queue, msg_ and connect_seq */
 319         /* discard existing out_queue and msg_seq */
 320         ceph_msg_remove_list(&con->out_queue);
 321         ceph_msg_remove_list(&con->out_sent);
 322
 323         if (con->in_msg) {
 324                 ceph_msg_put(con->in_msg);
 325                 con->in_msg = NULL;
 326         }
 327
 328         con->connect_seq = 0;
 329         con->out_seq = 0;
 330         if (con->out_msg) {
 331                 ceph_msg_put(con->out_msg);
 332                 con->out_msg = NULL;
 333         }
 334         con->in_seq = 0;
 335 }
 336
 337 /*
 338  * mark a peer down.  drop any open connections.
 339  */
 340 void ceph_con_close(struct ceph_connection *con)
 341 {
 342         dout("con_close %p peer %s\n", con, pr_addr(&con->peer_addr.in_addr));
 343         set_bit(CLOSED, &con->state);  /* in case there's queued work */
 344         clear_bit(STANDBY, &con->state);  /* avoid connect_seq bump */
 345         mutex_lock(&con->mutex);
 346         reset_connection(con);
 347         mutex_unlock(&con->mutex);
 348         queue_con(con);
 349 }
 350
 351 /*
 352  * Reopen a closed connection, with a new peer address.
 353  */
 354 void ceph_con_open(struct ceph_connection *con, struct ceph_entity_addr *addr)
 355 {
 356         dout("con_open %p %s\n", con, pr_addr(&addr->in_addr));
 357         set_bit(OPENING, &con->state);
 358         clear_bit(CLOSED, &con->state);
 359         memcpy(&con->peer_addr, addr, sizeof(*addr));
 360         con->delay = 0;      /* reset backoff memory */
 361         queue_con(con);
 362 }
 363
 364 /*
 365  * generic get/put
 366  */
 367 struct ceph_connection *ceph_con_get(struct ceph_connection *con)
 368 {
 369         dout("con_get %p nref = %d -> %d\n", con,
 370              atomic_read(&con->nref), atomic_read(&con->nref) + 1);
 371         if (atomic_inc_not_zero(&con->nref))
 372                 return con;
 373         return NULL;
 374 }
 375
 376 void ceph_con_put(struct ceph_connection *con)
 377 {
 378         dout("con_put %p nref = %d -> %d\n", con,
 379              atomic_read(&con->nref), atomic_read(&con->nref) - 1);
 380         BUG_ON(atomic_read(&con->nref) == 0);
 381         if (atomic_dec_and_test(&con->nref)) {
 382                 BUG_ON(con->sock);
 383                 kfree(con);
 384         }
 385 }
 386
 387 /*
 388  * initialize a new connection.
 389  */
 390 void ceph_con_init(struct ceph_messenger *msgr, struct ceph_connection *con)
 391 {
 392         dout("con_init %p\n", con);
 393         memset(con, 0, sizeof(*con));
 394         atomic_set(&con->nref, 1);
 395         con->msgr = msgr;
 396         mutex_init(&con->mutex);
 397         INIT_LIST_HEAD(&con->out_queue);
 398         INIT_LIST_HEAD(&con->out_sent);
 399         INIT_DELAYED_WORK(&con->work, con_work);
 400 }
 401
 402
 403 /*
 404  * We maintain a global counter to order connection attempts.  Get
 405  * a unique seq greater than @gt.
 406  */
 407 static u32 get_global_seq(struct ceph_messenger *msgr, u32 gt)
 408 {
 409         u32 ret;
 410
 411         spin_lock(&msgr->global_seq_lock);
 412         if (msgr->global_seq < gt)
 413                 msgr->global_seq = gt;
 414         ret = ++msgr->global_seq;
 415         spin_unlock(&msgr->global_seq_lock);
 416         return ret;
 417 }
 418
 419
 420 /*
 421  * Prepare footer for currently outgoing message, and finish things
 422  * off.  Assumes out_kvec* are already valid.. we just add on to the end.
 423  */
 424 static void prepare_write_message_footer(struct ceph_connection *con, int v)
 425 {
 426         struct ceph_msg *m = con->out_msg;
 427
 428         dout("prepare_write_message_footer %p\n", con);
 429         con->out_kvec_is_msg = true;
 430         con->out_kvec[v].iov_base = &m->footer;
 431         con->out_kvec[v].iov_len = sizeof(m->footer);
 432         con->out_kvec_bytes += sizeof(m->footer);
 433         con->out_kvec_left++;
 434         con->out_more = m->more_to_follow;
 435         con->out_msg_done = true;
 436 }
 437
 438 /*
 439  * Prepare headers for the next outgoing message.
 440  */
 441 static void prepare_write_message(struct ceph_connection *con)
 442 {
 443         struct ceph_msg *m;
 444         int v = 0;
 445
 446         con->out_kvec_bytes = 0;
 447         con->out_kvec_is_msg = true;
 448         con->out_msg_done = false;
 449
 450         /* Sneak an ack in there first?  If we can get it into the same
 451          * TCP packet that's a good thing. */
 452         if (con->in_seq > con->in_seq_acked) {
 453                 con->in_seq_acked = con->in_seq;
 454                 con->out_kvec[v].iov_base = &tag_ack;
 455                 con->out_kvec[v++].iov_len = 1;
 456                 con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
 457                 con->out_kvec[v].iov_base = &con->out_temp_ack;
 458                 con->out_kvec[v++].iov_len = sizeof(con->out_temp_ack);
 459                 con->out_kvec_bytes = 1 + sizeof(con->out_temp_ack);
 460         }
 461
 462         m = list_first_entry(&con->out_queue,
 463                        struct ceph_msg, list_head);
 464         con->out_msg = m;
 465         if (test_bit(LOSSYTX, &con->state)) {
 466                 /* put message on sent list */
 467                 ceph_msg_get(m);
 468                 list_move_tail(&m->list_head, &con->out_sent);
 469         } else {
 470                 list_del_init(&m->list_head);
 471         }
 472
 473         m->hdr.seq = cpu_to_le64(++con->out_seq);
 474
 475         dout("prepare_write_message %p seq %lld type %d len %d+%d+%d %d pgs\n",
 476              m, con->out_seq, le16_to_cpu(m->hdr.type),
 477              le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
 478              le32_to_cpu(m->hdr.data_len),
 479              m->nr_pages);
 480         BUG_ON(le32_to_cpu(m->hdr.front_len) != m->front.iov_len);
 481
 482         /* tag + hdr + front + middle */
 483         con->out_kvec[v].iov_base = &tag_msg;
 484         con->out_kvec[v++].iov_len = 1;
 485         con->out_kvec[v].iov_base = &m->hdr;
 486         con->out_kvec[v++].iov_len = sizeof(m->hdr);
 487         con->out_kvec[v++] = m->front;
 488         if (m->middle)
 489                 con->out_kvec[v++] = m->middle->vec;
 490         con->out_kvec_left = v;
 491         con->out_kvec_bytes += 1 + sizeof(m->hdr) + m->front.iov_len +
 492                 (m->middle ? m->middle->vec.iov_len : 0);
 493         con->out_kvec_cur = con->out_kvec;
 494
 495         /* fill in crc (except data pages), footer */
 496         con->out_msg->hdr.crc =
 497                 cpu_to_le32(crc32c(0, (void *)&m->hdr,
 498                                       sizeof(m->hdr) - sizeof(m->hdr.crc)));
 499         con->out_msg->footer.flags = CEPH_MSG_FOOTER_COMPLETE;
 500         con->out_msg->footer.front_crc =
 501                 cpu_to_le32(crc32c(0, m->front.iov_base, m->front.iov_len));
 502         if (m->middle)
 503                 con->out_msg->footer.middle_crc =
 504                         cpu_to_le32(crc32c(0, m->middle->vec.iov_base,
 505                                            m->middle->vec.iov_len));
 506         else
 507                 con->out_msg->footer.middle_crc = 0;
 508         con->out_msg->footer.data_crc = 0;
 509         dout("prepare_write_message front_crc %u data_crc %u\n",
 510              le32_to_cpu(con->out_msg->footer.front_crc),
 511              le32_to_cpu(con->out_msg->footer.middle_crc));
 512
 513         /* is there a data payload? */
 514         if (le32_to_cpu(m->hdr.data_len) > 0) {
 515                 /* initialize page iterator */
 516                 con->out_msg_pos.page = 0;
 517                 con->out_msg_pos.page_pos =
 518                         le16_to_cpu(m->hdr.data_off) & ~PAGE_MASK;
 519                 con->out_msg_pos.data_pos = 0;
 520                 con->out_msg_pos.did_page_crc = 0;
 521                 con->out_more = 1;  /* data + footer will follow */
 522         } else {
 523                 /* no, queue up footer too and be done */
 524                 prepare_write_message_footer(con, v);
 525         }
 526
 527         set_bit(WRITE_PENDING, &con->state);
 528 }
 529
 530 /*
 531  * Prepare an ack.
 532  */
 533 static void prepare_write_ack(struct ceph_connection *con)
 534 {
 535         dout("prepare_write_ack %p %llu -> %llu\n", con,
 536              con->in_seq_acked, con->in_seq);
 537         con->in_seq_acked = con->in_seq;
 538
 539         con->out_kvec[0].iov_base = &tag_ack;
 540         con->out_kvec[0].iov_len = 1;
 541         con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
 542         con->out_kvec[1].iov_base = &con->out_temp_ack;
 543         con->out_kvec[1].iov_len = sizeof(con->out_temp_ack);
 544         con->out_kvec_left = 2;
 545         con->out_kvec_bytes = 1 + sizeof(con->out_temp_ack);
 546         con->out_kvec_cur = con->out_kvec;
 547         con->out_more = 1;  /* more will follow.. eventually.. */
 548         set_bit(WRITE_PENDING, &con->state);
 549 }
 550
 551 /*
 552  * Prepare to write keepalive byte.
 553  */
 554 static void prepare_write_keepalive(struct ceph_connection *con)
 555 {
 556         dout("prepare_write_keepalive %p\n", con);
 557         con->out_kvec[0].iov_base = &tag_keepalive;
 558         con->out_kvec[0].iov_len = 1;
 559         con->out_kvec_left = 1;
 560         con->out_kvec_bytes = 1;
 561         con->out_kvec_cur = con->out_kvec;
 562         set_bit(WRITE_PENDING, &con->state);
 563 }
 564
 565 /*
 566  * Connection negotiation.
 567  */
 568
 569 static void prepare_connect_authorizer(struct ceph_connection *con)
 570 {
 571         void *auth_buf;
 572         int auth_len = 0;
 573         int auth_protocol = 0;
 574
 575         mutex_unlock(&con->mutex);
 576         if (con->ops->get_authorizer)
 577                 con->ops->get_authorizer(con, &auth_buf, &auth_len,
 578                                          &auth_protocol, &con->auth_reply_buf,
 579                                          &con->auth_reply_buf_len,
 580                                          con->auth_retry);
 581         mutex_lock(&con->mutex);
 582
 583         con->out_connect.authorizer_protocol = cpu_to_le32(auth_protocol);
 584         con->out_connect.authorizer_len = cpu_to_le32(auth_len);
 585
 586         con->out_kvec[con->out_kvec_left].iov_base = auth_buf;
 587         con->out_kvec[con->out_kvec_left].iov_len = auth_len;
 588         con->out_kvec_left++;
 589         con->out_kvec_bytes += auth_len;
 590 }
 591
 592 /*
 593  * We connected to a peer and are saying hello.
 594  */
 595 static void prepare_write_banner(struct ceph_messenger *msgr,
 596                                  struct ceph_connection *con)
 597 {
 598         int len = strlen(CEPH_BANNER);
 599
 600         con->out_kvec[0].iov_base = CEPH_BANNER;
 601         con->out_kvec[0].iov_len = len;
 602         con->out_kvec[1].iov_base = &msgr->my_enc_addr;
 603         con->out_kvec[1].iov_len = sizeof(msgr->my_enc_addr);
 604         con->out_kvec_left = 2;
 605         con->out_kvec_bytes = len + sizeof(msgr->my_enc_addr);
 606         con->out_kvec_cur = con->out_kvec;
 607         con->out_more = 0;
 608         set_bit(WRITE_PENDING, &con->state);
 609 }
 610
 611 static void prepare_write_connect(struct ceph_messenger *msgr,
 612                                   struct ceph_connection *con,
 613                                   int after_banner)
 614 {
 615         unsigned global_seq = get_global_seq(con->msgr, 0);
 616         int proto;
 617
 618         switch (con->peer_name.type) {
 619         case CEPH_ENTITY_TYPE_MON:
 620                 proto = CEPH_MONC_PROTOCOL;
 621                 break;
 622         case CEPH_ENTITY_TYPE_OSD:
 623                 proto = CEPH_OSDC_PROTOCOL;
 624                 break;
 625         case CEPH_ENTITY_TYPE_MDS:
 626                 proto = CEPH_MDSC_PROTOCOL;
 627                 break;
 628         default:
 629                 BUG();
 630         }
 631
 632         dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
 633              con->connect_seq, global_seq, proto);
 634
 635         con->out_connect.features = CEPH_FEATURE_SUPPORTED;
 636         con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
 637         con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
 638         con->out_connect.global_seq = cpu_to_le32(global_seq);
 639         con->out_connect.protocol_version = cpu_to_le32(proto);
 640         con->out_connect.flags = 0;
 641
 642         if (!after_banner) {
 643                 con->out_kvec_left = 0;
 644                 con->out_kvec_bytes = 0;
 645         }
 646         con->out_kvec[con->out_kvec_left].iov_base = &con->out_connect;
 647         con->out_kvec[con->out_kvec_left].iov_len = sizeof(con->out_connect);
 648         con->out_kvec_left++;
 649         con->out_kvec_bytes += sizeof(con->out_connect);
 650         con->out_kvec_cur = con->out_kvec;
 651         con->out_more = 0;
 652         set_bit(WRITE_PENDING, &con->state);
 653
 654         prepare_connect_authorizer(con);
 655 }
 656
 657
 658 /*
 659  * write as much of pending kvecs to the socket as we can.
 660  *  1 -> done
 661  *  0 -> socket full, but more to do
 662  * <0 -> error
 663  */
 664 static int write_partial_kvec(struct ceph_connection *con)
 665 {
 666         int ret;
 667
 668         dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
 669         while (con->out_kvec_bytes > 0) {
 670                 ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
 671                                        con->out_kvec_left, con->out_kvec_bytes,
 672                                        con->out_more);
 673                 if (ret <= 0)
 674                         goto out;
 675                 con->out_kvec_bytes -= ret;
 676                 if (con->out_kvec_bytes == 0)
 677                         break;            /* done */
 678                 while (ret > 0) {
 679                         if (ret >= con->out_kvec_cur->iov_len) {
 680                                 ret -= con->out_kvec_cur->iov_len;
 681                                 con->out_kvec_cur++;
 682                                 con->out_kvec_left--;
 683                         } else {
 684                                 con->out_kvec_cur->iov_len -= ret;
 685                                 con->out_kvec_cur->iov_base += ret;
 686                                 ret = 0;
 687                                 break;
 688                         }
 689                 }
 690         }
 691         con->out_kvec_left = 0;
 692         con->out_kvec_is_msg = false;
 693         ret = 1;
 694 out:
 695         dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
 696              con->out_kvec_bytes, con->out_kvec_left, ret);
 697         return ret;  /* done! */
 698 }
 699
 700 /*
 701  * Write as much message data payload as we can.  If we finish, queue
 702  * up the footer.
 703  *  1 -> done, footer is now queued in out_kvec[].
 704  *  0 -> socket full, but more to do
 705  * <0 -> error
 706  */
 707 static int write_partial_msg_pages(struct ceph_connection *con)
 708 {
 709         struct ceph_msg *msg = con->out_msg;
 710         unsigned data_len = le32_to_cpu(msg->hdr.data_len);
 711         size_t len;
 712         int crc = con->msgr->nocrc;
 713         int ret;
 714
 715         dout("write_partial_msg_pages %p msg %p page %d/%d offset %d\n",
 716              con, con->out_msg, con->out_msg_pos.page, con->out_msg->nr_pages,
 717              con->out_msg_pos.page_pos);
 718
 719         while (con->out_msg_pos.page < con->out_msg->nr_pages) {
 720                 struct page *page = NULL;
 721                 void *kaddr = NULL;
 722
 723                 /*
 724                  * if we are calculating the data crc (the default), we need
 725                  * to map the page.  if our pages[] has been revoked, use the
 726                  * zero page.
 727                  */
 728                 if (msg->pages) {
 729                         page = msg->pages[con->out_msg_pos.page];
 730                         if (crc)
 731                                 kaddr = kmap(page);
 732                 } else if (msg->pagelist) {
 733                         page = list_first_entry(&msg->pagelist->head,
 734                                                 struct page, lru);
 735                         if (crc)
 736                                 kaddr = kmap(page);
 737                 } else {
 738                         page = con->msgr->zero_page;
 739                         if (crc)
 740                                 kaddr = page_address(con->msgr->zero_page);
 741                 }
 742                 len = min((int)(PAGE_SIZE - con->out_msg_pos.page_pos),
 743                           (int)(data_len - con->out_msg_pos.data_pos));
 744                 if (crc && !con->out_msg_pos.did_page_crc) {
 745                         void *base = kaddr + con->out_msg_pos.page_pos;
 746                         u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc);
 747
 748                         BUG_ON(kaddr == NULL);
 749                         con->out_msg->footer.data_crc =
 750                                 cpu_to_le32(crc32c(tmpcrc, base, len));
 751                         con->out_msg_pos.did_page_crc = 1;
 752                 }
 753
 754                 ret = kernel_sendpage(con->sock, page,
 755                                       con->out_msg_pos.page_pos, len,
 756                                       MSG_DONTWAIT | MSG_NOSIGNAL |
 757                                       MSG_MORE);
 758
 759                 if (crc && (msg->pages || msg->pagelist))
 760                         kunmap(page);
 761
 762                 if (ret <= 0)
 763                         goto out;
 764
 765                 con->out_msg_pos.data_pos += ret;
 766                 con->out_msg_pos.page_pos += ret;
 767                 if (ret == len) {
 768                         con->out_msg_pos.page_pos = 0;
 769                         con->out_msg_pos.page++;
 770                         con->out_msg_pos.did_page_crc = 0;
 771                         if (msg->pagelist)
 772                                 list_move_tail(&page->lru,
 773                                                &msg->pagelist->head);
 774                 }
 775         }
 776
 777         dout("write_partial_msg_pages %p msg %p done\n", con, msg);
 778
 779         /* prepare and queue up footer, too */
 780         if (!crc)
 781                 con->out_msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
 782         con->out_kvec_bytes = 0;
 783         con->out_kvec_left = 0;
 784         con->out_kvec_cur = con->out_kvec;
 785         prepare_write_message_footer(con, 0);
 786         ret = 1;
 787 out:
 788         return ret;
 789 }
 790
 791 /*
 792  * write some zeros
 793  */
 794 static int write_partial_skip(struct ceph_connection *con)
 795 {
 796         int ret;
 797
 798         while (con->out_skip > 0) {
 799                 struct kvec iov = {
 800                         .iov_base = page_address(con->msgr->zero_page),
 801                         .iov_len = min(con->out_skip, (int)PAGE_CACHE_SIZE)
 802                 };
 803
 804                 ret = ceph_tcp_sendmsg(con->sock, &iov, 1, iov.iov_len, 1);
 805                 if (ret <= 0)
 806                         goto out;
 807                 con->out_skip -= ret;
 808         }
 809         ret = 1;
 810 out:
 811         return ret;
 812 }
 813
 814 /*
 815  * Prepare to read connection handshake, or an ack.
 816  */
 817 static void prepare_read_banner(struct ceph_connection *con)
 818 {
 819         dout("prepare_read_banner %p\n", con);
 820         con->in_base_pos = 0;
 821 }
 822
 823 static void prepare_read_connect(struct ceph_connection *con)
 824 {
 825         dout("prepare_read_connect %p\n", con);
 826         con->in_base_pos = 0;
 827 }
 828
 829 static void prepare_read_connect_retry(struct ceph_connection *con)
 830 {
 831         dout("prepare_read_connect_retry %p\n", con);
 832         con->in_base_pos = strlen(CEPH_BANNER) + sizeof(con->actual_peer_addr)
 833                 + sizeof(con->peer_addr_for_me);
 834 }
 835
 836 static void prepare_read_ack(struct ceph_connection *con)
 837 {
 838         dout("prepare_read_ack %p\n", con);
 839         con->in_base_pos = 0;
 840 }
 841
 842 static void prepare_read_tag(struct ceph_connection *con)
 843 {
 844         dout("prepare_read_tag %p\n", con);
 845         con->in_base_pos = 0;
 846         con->in_tag = CEPH_MSGR_TAG_READY;
 847 }
 848
 849 /*
 850  * Prepare to read a message.
 851  */
 852 static int prepare_read_message(struct ceph_connection *con)
 853 {
 854         dout("prepare_read_message %p\n", con);
 855         BUG_ON(con->in_msg != NULL);
 856         con->in_base_pos = 0;
 857         con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
 858         return 0;
 859 }
 860
 861
 862 static int read_partial(struct ceph_connection *con,
 863                         int *to, int size, void *object)
 864 {
 865         *to += size;
 866         while (con->in_base_pos < *to) {
 867                 int left = *to - con->in_base_pos;
 868                 int have = size - left;
 869                 int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
 870                 if (ret <= 0)
 871                         return ret;
 872                 con->in_base_pos += ret;
 873         }
 874         return 1;
 875 }
 876
 877
 878 /*
 879  * Read all or part of the connect-side handshake on a new connection
 880  */
 881 static int read_partial_banner(struct ceph_connection *con)
 882 {
 883         int ret, to = 0;
 884
 885         dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
 886
 887         /* peer's banner */
 888         ret = read_partial(con, &to, strlen(CEPH_BANNER), con->in_banner);
 889         if (ret <= 0)
 890                 goto out;
 891         ret = read_partial(con, &to, sizeof(con->actual_peer_addr),
 892                            &con->actual_peer_addr);
 893         if (ret <= 0)
 894                 goto out;
 895         ret = read_partial(con, &to, sizeof(con->peer_addr_for_me),
 896                            &con->peer_addr_for_me);
 897         if (ret <= 0)
 898                 goto out;
 899 out:
 900         return ret;
 901 }
 902
 903 static int read_partial_connect(struct ceph_connection *con)
 904 {
 905         int ret, to = 0;
 906
 907         dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
 908
 909         ret = read_partial(con, &to, sizeof(con->in_reply), &con->in_reply);
 910         if (ret <= 0)
 911                 goto out;
 912         ret = read_partial(con, &to, le32_to_cpu(con->in_reply.authorizer_len),
 913                            con->auth_reply_buf);
 914         if (ret <= 0)
 915                 goto out;
 916
 917         dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
 918              con, (int)con->in_reply.tag,
 919              le32_to_cpu(con->in_reply.connect_seq),
 920              le32_to_cpu(con->in_reply.global_seq));
 921 out:
 922         return ret;
 923
 924 }
 925
 926 /*
 927  * Verify the hello banner looks okay.
 928  */
 929 static int verify_hello(struct ceph_connection *con)
 930 {
 931         if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
 932                 pr_err("connect to %s got bad banner\n",
 933                        pr_addr(&con->peer_addr.in_addr));
 934                 con->error_msg = "protocol error, bad banner";
 935                 return -1;
 936         }
 937         return 0;
 938 }
 939
 940 static bool addr_is_blank(struct sockaddr_storage *ss)
 941 {
 942         switch (ss->ss_family) {
 943         case AF_INET:
 944                 return ((struct sockaddr_in *)ss)->sin_addr.s_addr == 0;
 945         case AF_INET6:
 946                 return
 947                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[0] == 0 &&
 948                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[1] == 0 &&
 949                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[2] == 0 &&
 950                      ((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[3] == 0;
 951         }
 952         return false;
 953 }
 954
 955 static int addr_port(struct sockaddr_storage *ss)
 956 {
 957         switch (ss->ss_family) {
 958         case AF_INET:
 959                 return ntohs(((struct sockaddr_in *)ss)->sin_port);
 960         case AF_INET6:
 961                 return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
 962         }
 963         return 0;
 964 }
 965
 966 static void addr_set_port(struct sockaddr_storage *ss, int p)
 967 {
 968         switch (ss->ss_family) {
 969         case AF_INET:
 970                 ((struct sockaddr_in *)ss)->sin_port = htons(p);
 971         case AF_INET6:
 972                 ((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
 973         }
 974 }
 975
 976 /*
 977  * Parse an ip[:port] list into an addr array.  Use the default
 978  * monitor port if a port isn't specified.
 979  */
 980 int ceph_parse_ips(const char *c, const char *end,
 981                    struct ceph_entity_addr *addr,
 982                    int max_count, int *count)
 983 {
 984         int i;
 985         const char *p = c;
 986
 987         dout("parse_ips on '%.*s'\n", (int)(end-c), c);
 988         for (i = 0; i < max_count; i++) {
 989                 const char *ipend;
 990                 struct sockaddr_storage *ss = &addr[i].in_addr;
 991                 struct sockaddr_in *in4 = (void *)ss;
 992                 struct sockaddr_in6 *in6 = (void *)ss;
 993                 int port;
 994
 995                 memset(ss, 0, sizeof(*ss));
 996                 if (in4_pton(p, end - p, (u8 *)&in4->sin_addr.s_addr,
 997                              ',', &ipend)) {
 998                         ss->ss_family = AF_INET;
 999                 } else if (in6_pton(p, end - p, (u8 *)&in6->sin6_addr.s6_addr,
1000                                     ',', &ipend)) {
1001                         ss->ss_family = AF_INET6;
1002                 } else {
1003                         goto bad;
1004                 }
1005                 p = ipend;
1006
1007                 /* port? */
1008                 if (p < end && *p == ':') {
1009                         port = 0;
1010                         p++;
1011                         while (p < end && *p >= '0' && *p <= '9') {
1012                                 port = (port * 10) + (*p - '0');
1013                                 p++;
1014                         }
1015                         if (port > 65535 || port == 0)
1016                                 goto bad;
1017                 } else {
1018                         port = CEPH_MON_PORT;
1019                 }
1020
1021                 addr_set_port(ss, port);
1022
1023                 dout("parse_ips got %s\n", pr_addr(ss));
1024
1025                 if (p == end)
1026                         break;
1027                 if (*p != ',')
1028                         goto bad;
1029                 p++;
1030         }
1031
1032         if (p != end)
1033                 goto bad;
1034
1035         if (count)
1036                 *count = i + 1;
1037         return 0;
1038
1039 bad:
1040         pr_err("parse_ips bad ip '%s'\n", c);
1041         return -EINVAL;
1042 }
1043
1044 static int process_banner(struct ceph_connection *con)
1045 {
1046         dout("process_banner on %p\n", con);
1047
1048         if (verify_hello(con) < 0)
1049                 return -1;
1050
1051         ceph_decode_addr(&con->actual_peer_addr);
1052         ceph_decode_addr(&con->peer_addr_for_me);
1053
1054         /*
1055          * Make sure the other end is who we wanted.  note that the other
1056          * end may not yet know their ip address, so if it's 0.0.0.0, give
1057          * them the benefit of the doubt.
1058          */
1059         if (memcmp(&con->peer_addr, &con->actual_peer_addr,
1060                    sizeof(con->peer_addr)) != 0 &&
1061             !(addr_is_blank(&con->actual_peer_addr.in_addr) &&
1062               con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
1063                 pr_warning("wrong peer, want %s/%lld, got %s/%lld\n",
1064                            pr_addr(&con->peer_addr.in_addr),
1065                            le64_to_cpu(con->peer_addr.nonce),
1066                            pr_addr(&con->actual_peer_addr.in_addr),
1067                            le64_to_cpu(con->actual_peer_addr.nonce));
1068                 con->error_msg = "wrong peer at address";
1069                 return -1;
1070         }
1071
1072         /*
1073          * did we learn our address?
1074          */
1075         if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
1076                 int port = addr_port(&con->msgr->inst.addr.in_addr);
1077
1078                 memcpy(&con->msgr->inst.addr.in_addr,
1079                        &con->peer_addr_for_me.in_addr,
1080                        sizeof(con->peer_addr_for_me.in_addr));
1081                 addr_set_port(&con->msgr->inst.addr.in_addr, port);
1082                 encode_my_addr(con->msgr);
1083                 dout("process_banner learned my addr is %s\n",
1084                      pr_addr(&con->msgr->inst.addr.in_addr));
1085         }
1086
1087         set_bit(NEGOTIATING, &con->state);
1088         prepare_read_connect(con);
1089         return 0;
1090 }
1091
1092 static void fail_protocol(struct ceph_connection *con)
1093 {
1094         reset_connection(con);
1095         set_bit(CLOSED, &con->state);  /* in case there's queued work */
1096
1097         mutex_unlock(&con->mutex);
1098         if (con->ops->bad_proto)
1099                 con->ops->bad_proto(con);
1100         mutex_lock(&con->mutex);
1101 }
1102
1103 static int process_connect(struct ceph_connection *con)
1104 {
1105         u64 sup_feat = CEPH_FEATURE_SUPPORTED;
1106         u64 req_feat = CEPH_FEATURE_REQUIRED;
1107         u64 server_feat = le64_to_cpu(con->in_reply.features);
1108
1109         dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
1110
1111         switch (con->in_reply.tag) {
1112         case CEPH_MSGR_TAG_FEATURES:
1113                 pr_err("%s%lld %s feature set mismatch,"
1114                        " my %llx < server's %llx, missing %llx\n",
1115                        ENTITY_NAME(con->peer_name),
1116                        pr_addr(&con->peer_addr.in_addr),
1117                        sup_feat, server_feat, server_feat & ~sup_feat);
1118                 con->error_msg = "missing required protocol features";
1119                 fail_protocol(con);
1120                 return -1;
1121
1122         case CEPH_MSGR_TAG_BADPROTOVER:
1123                 pr_err("%s%lld %s protocol version mismatch,"
1124                        " my %d != server's %d\n",
1125                        ENTITY_NAME(con->peer_name),
1126                        pr_addr(&con->peer_addr.in_addr),
1127                        le32_to_cpu(con->out_connect.protocol_version),
1128                        le32_to_cpu(con->in_reply.protocol_version));
1129                 con->error_msg = "protocol version mismatch";
1130                 fail_protocol(con);
1131                 return -1;
1132
1133         case CEPH_MSGR_TAG_BADAUTHORIZER:
1134                 con->auth_retry++;
1135                 dout("process_connect %p got BADAUTHORIZER attempt %d\n", con,
1136                      con->auth_retry);
1137                 if (con->auth_retry == 2) {
1138                         con->error_msg = "connect authorization failure";
1139                         reset_connection(con);
1140                         set_bit(CLOSED, &con->state);
1141                         return -1;
1142                 }
1143                 con->auth_retry = 1;
1144                 prepare_write_connect(con->msgr, con, 0);
1145                 prepare_read_connect_retry(con);
1146                 break;
1147
1148         case CEPH_MSGR_TAG_RESETSESSION:
1149                 /*
1150                  * If we connected with a large connect_seq but the peer
1151                  * has no record of a session with us (no connection, or
1152                  * connect_seq == 0), they will send RESETSESION to indicate
1153                  * that they must have reset their session, and may have
1154                  * dropped messages.
1155                  */
1156                 dout("process_connect got RESET peer seq %u\n",
1157                      le32_to_cpu(con->in_connect.connect_seq));
1158                 pr_err("%s%lld %s connection reset\n",
1159                        ENTITY_NAME(con->peer_name),
1160                        pr_addr(&con->peer_addr.in_addr));
1161                 reset_connection(con);
1162                 prepare_write_connect(con->msgr, con, 0);
1163                 prepare_read_connect(con);
1164
1165                 /* Tell ceph about it. */
1166                 mutex_unlock(&con->mutex);
1167                 pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));
1168                 if (con->ops->peer_reset)
1169                         con->ops->peer_reset(con);
1170                 mutex_lock(&con->mutex);
1171                 break;
1172
1173         case CEPH_MSGR_TAG_RETRY_SESSION:
1174                 /*
1175                  * If we sent a smaller connect_seq than the peer has, try
1176                  * again with a larger value.
1177                  */
1178                 dout("process_connect got RETRY my seq = %u, peer_seq = %u\n",
1179                      le32_to_cpu(con->out_connect.connect_seq),
1180                      le32_to_cpu(con->in_connect.connect_seq));
1181                 con->connect_seq = le32_to_cpu(con->in_connect.connect_seq);
1182                 prepare_write_connect(con->msgr, con, 0);
1183                 prepare_read_connect(con);
1184                 break;
1185
1186         case CEPH_MSGR_TAG_RETRY_GLOBAL:
1187                 /*
1188                  * If we sent a smaller global_seq than the peer has, try
1189                  * again with a larger value.
1190                  */
1191                 dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
1192                      con->peer_global_seq,
1193                      le32_to_cpu(con->in_connect.global_seq));
1194                 get_global_seq(con->msgr,
1195                                le32_to_cpu(con->in_connect.global_seq));
1196                 prepare_write_connect(con->msgr, con, 0);
1197                 prepare_read_connect(con);
1198                 break;
1199
1200         case CEPH_MSGR_TAG_READY:
1201                 if (req_feat & ~server_feat) {
1202                         pr_err("%s%lld %s protocol feature mismatch,"
1203                                " my required %llx > server's %llx, need %llx\n",
1204                                ENTITY_NAME(con->peer_name),
1205                                pr_addr(&con->peer_addr.in_addr),
1206                                req_feat, server_feat, req_feat & ~server_feat);
1207                         con->error_msg = "missing required protocol features";
1208                         fail_protocol(con);
1209                         return -1;
1210                 }
1211                 clear_bit(CONNECTING, &con->state);
1212                 con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
1213                 con->connect_seq++;
1214                 dout("process_connect got READY gseq %d cseq %d (%d)\n",
1215                      con->peer_global_seq,
1216                      le32_to_cpu(con->in_reply.connect_seq),
1217                      con->connect_seq);
1218                 WARN_ON(con->connect_seq !=
1219                         le32_to_cpu(con->in_reply.connect_seq));
1220
1221                 if (con->in_reply.flags & CEPH_MSG_CONNECT_LOSSY)
1222                         set_bit(LOSSYTX, &con->state);
1223
1224                 prepare_read_tag(con);
1225                 break;
1226
1227         case CEPH_MSGR_TAG_WAIT:
1228                 /*
1229                  * If there is a connection race (we are opening
1230                  * connections to each other), one of us may just have
1231                  * to WAIT.  This shouldn't happen if we are the
1232                  * client.
1233                  */
1234                 pr_err("process_connect peer connecting WAIT\n");
1235
1236         default:
1237                 pr_err("connect protocol error, will retry\n");
1238                 con->error_msg = "protocol error, garbage tag during connect";
1239                 return -1;
1240         }
1241         return 0;
1242 }
1243
1244
1245 /*
1246  * read (part of) an ack
1247  */
1248 static int read_partial_ack(struct ceph_connection *con)
1249 {
1250         int to = 0;
1251
1252         return read_partial(con, &to, sizeof(con->in_temp_ack),
1253                             &con->in_temp_ack);
1254 }
1255
1256
1257 /*
1258  * We can finally discard anything that's been acked.
1259  */
1260 static void process_ack(struct ceph_connection *con)
1261 {
1262         struct ceph_msg *m;
1263         u64 ack = le64_to_cpu(con->in_temp_ack);
1264         u64 seq;
1265
1266         while (!list_empty(&con->out_sent)) {
1267                 m = list_first_entry(&con->out_sent, struct ceph_msg,
1268                                      list_head);
1269                 seq = le64_to_cpu(m->hdr.seq);
1270                 if (seq > ack)
1271                         break;
1272                 dout("got ack for seq %llu type %d at %p\n", seq,
1273                      le16_to_cpu(m->hdr.type), m);
1274                 ceph_msg_remove(m);
1275         }
1276         prepare_read_tag(con);
1277 }
1278
1279
1280
1281
1282 static int read_partial_message_section(struct ceph_connection *con,
1283                                         struct kvec *section, unsigned int sec_len,
1284                                         u32 *crc)
1285 {
1286         int left;
1287         int ret;
1288
1289         BUG_ON(!section);
1290
1291         while (section->iov_len < sec_len) {
1292                 BUG_ON(section->iov_base == NULL);
1293                 left = sec_len - section->iov_len;
1294                 ret = ceph_tcp_recvmsg(con->sock, (char *)section->iov_base +
1295                                        section->iov_len, left);
1296                 if (ret <= 0)
1297                         return ret;
1298                 section->iov_len += ret;
1299                 if (section->iov_len == sec_len)
1300                         *crc = crc32c(0, section->iov_base,
1301                                       section->iov_len);
1302         }
1303
1304         return 1;
1305 }
1306
1307 static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
1308                                 struct ceph_msg_header *hdr,
1309                                 int *skip);
1310 /*
1311  * read (part of) a message.
1312  */
1313 static int read_partial_message(struct ceph_connection *con)
1314 {
1315         struct ceph_msg *m = con->in_msg;
1316         void *p;
1317         int ret;
1318         int to, left;
1319         unsigned front_len, middle_len, data_len, data_off;
1320         int datacrc = con->msgr->nocrc;
1321         int skip;
1322
1323         dout("read_partial_message con %p msg %p\n", con, m);
1324
1325         /* header */
1326         while (con->in_base_pos < sizeof(con->in_hdr)) {
1327                 left = sizeof(con->in_hdr) - con->in_base_pos;
1328                 ret = ceph_tcp_recvmsg(con->sock,
1329                                        (char *)&con->in_hdr + con->in_base_pos,
1330                                        left);
1331                 if (ret <= 0)
1332                         return ret;
1333                 con->in_base_pos += ret;
1334                 if (con->in_base_pos == sizeof(con->in_hdr)) {
1335                         u32 crc = crc32c(0, (void *)&con->in_hdr,
1336                                  sizeof(con->in_hdr) - sizeof(con->in_hdr.crc));
1337                         if (crc != le32_to_cpu(con->in_hdr.crc)) {
1338                                 pr_err("read_partial_message bad hdr "
1339                                        " crc %u != expected %u\n",
1340                                        crc, con->in_hdr.crc);
1341                                 return -EBADMSG;
1342                         }
1343                 }
1344         }
1345         front_len = le32_to_cpu(con->in_hdr.front_len);
1346         if (front_len > CEPH_MSG_MAX_FRONT_LEN)
1347                 return -EIO;
1348         middle_len = le32_to_cpu(con->in_hdr.middle_len);
1349         if (middle_len > CEPH_MSG_MAX_DATA_LEN)
1350                 return -EIO;
1351         data_len = le32_to_cpu(con->in_hdr.data_len);
1352         if (data_len > CEPH_MSG_MAX_DATA_LEN)
1353                 return -EIO;
1354         data_off = le16_to_cpu(con->in_hdr.data_off);
1355
1356         /* allocate message? */
1357         if (!con->in_msg) {
1358                 dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
1359                      con->in_hdr.front_len, con->in_hdr.data_len);
1360                 con->in_msg = ceph_alloc_msg(con, &con->in_hdr, &skip);
1361                 if (skip) {
1362                         /* skip this message */
1363                         pr_err("alloc_msg returned NULL, skipping message\n");
1364                         con->in_base_pos = -front_len - middle_len - data_len -
1365                                 sizeof(m->footer);
1366                         con->in_tag = CEPH_MSGR_TAG_READY;
1367                         return 0;
1368                 }
1369                 if (IS_ERR(con->in_msg)) {
1370                         ret = PTR_ERR(con->in_msg);
1371                         con->in_msg = NULL;
1372                         con->error_msg = "error allocating memory for incoming message";
1373                         return ret;
1374                 }
1375                 m = con->in_msg;
1376                 m->front.iov_len = 0;    /* haven't read it yet */
1377                 if (m->middle)
1378                         m->middle->vec.iov_len = 0;
1379
1380                 con->in_msg_pos.page = 0;
1381                 con->in_msg_pos.page_pos = data_off & ~PAGE_MASK;
1382                 con->in_msg_pos.data_pos = 0;
1383         }
1384
1385         /* front */
1386         ret = read_partial_message_section(con, &m->front, front_len,
1387                                            &con->in_front_crc);
1388         if (ret <= 0)
1389                 return ret;
1390
1391         /* middle */
1392         if (m->middle) {
1393                 ret = read_partial_message_section(con, &m->middle->vec, middle_len,
1394                                                    &con->in_middle_crc);
1395                 if (ret <= 0)
1396                         return ret;
1397         }
1398
1399         /* (page) data */
1400         while (con->in_msg_pos.data_pos < data_len) {
1401                 left = min((int)(data_len - con->in_msg_pos.data_pos),
1402                            (int)(PAGE_SIZE - con->in_msg_pos.page_pos));
1403                 BUG_ON(m->pages == NULL);
1404                 p = kmap(m->pages[con->in_msg_pos.page]);
1405                 ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
1406                                        left);
1407                 if (ret > 0 && datacrc)
1408                         con->in_data_crc =
1409                                 crc32c(con->in_data_crc,
1410                                           p + con->in_msg_pos.page_pos, ret);
1411                 kunmap(m->pages[con->in_msg_pos.page]);
1412                 if (ret <= 0)
1413                         return ret;
1414                 con->in_msg_pos.data_pos += ret;
1415                 con->in_msg_pos.page_pos += ret;
1416                 if (con->in_msg_pos.page_pos == PAGE_SIZE) {
1417                         con->in_msg_pos.page_pos = 0;
1418                         con->in_msg_pos.page++;
1419                 }
1420         }
1421
1422         /* footer */
1423         to = sizeof(m->hdr) + sizeof(m->footer);
1424         while (con->in_base_pos < to) {
1425                 left = to - con->in_base_pos;
1426                 ret = ceph_tcp_recvmsg(con->sock, (char *)&m->footer +
1427                                        (con->in_base_pos - sizeof(m->hdr)),
1428                                        left);
1429                 if (ret <= 0)
1430                         return ret;
1431                 con->in_base_pos += ret;
1432         }
1433         dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
1434              m, front_len, m->footer.front_crc, middle_len,
1435              m->footer.middle_crc, data_len, m->footer.data_crc);
1436
1437         /* crc ok? */
1438         if (con->in_front_crc != le32_to_cpu(m->footer.front_crc)) {
1439                 pr_err("read_partial_message %p front crc %u != exp. %u\n",
1440                        m, con->in_front_crc, m->footer.front_crc);
1441                 return -EBADMSG;
1442         }
1443         if (con->in_middle_crc != le32_to_cpu(m->footer.middle_crc)) {
1444                 pr_err("read_partial_message %p middle crc %u != exp %u\n",
1445                        m, con->in_middle_crc, m->footer.middle_crc);
1446                 return -EBADMSG;
1447         }
1448         if (datacrc &&
1449             (m->footer.flags & CEPH_MSG_FOOTER_NOCRC) == 0 &&
1450             con->in_data_crc != le32_to_cpu(m->footer.data_crc)) {
1451                 pr_err("read_partial_message %p data crc %u != exp. %u\n", m,
1452                        con->in_data_crc, le32_to_cpu(m->footer.data_crc));
1453                 return -EBADMSG;
1454         }
1455
1456         return 1; /* done! */
1457 }
1458
1459 /*
1460  * Process message.  This happens in the worker thread.  The callback should
1461  * be careful not to do anything that waits on other incoming messages or it
1462  * may deadlock.
1463  */
1464 static void process_message(struct ceph_connection *con)
1465 {
1466         struct ceph_msg *msg;
1467
1468         msg = con->in_msg;
1469         con->in_msg = NULL;
1470
1471         /* if first message, set peer_name */
1472         if (con->peer_name.type == 0)
1473                 con->peer_name = msg->hdr.src.name;
1474
1475         con->in_seq++;
1476         mutex_unlock(&con->mutex);
1477
1478         dout("===== %p %llu from %s%lld %d=%s len %d+%d (%u %u %u) =====\n",
1479              msg, le64_to_cpu(msg->hdr.seq),
1480              ENTITY_NAME(msg->hdr.src.name),
1481              le16_to_cpu(msg->hdr.type),
1482              ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
1483              le32_to_cpu(msg->hdr.front_len),
1484              le32_to_cpu(msg->hdr.data_len),
1485              con->in_front_crc, con->in_middle_crc, con->in_data_crc);
1486         con->ops->dispatch(con, msg);
1487
1488         mutex_lock(&con->mutex);
1489         prepare_read_tag(con);
1490 }
1491
1492
1493 /*
1494  * Write something to the socket.  Called in a worker thread when the
1495  * socket appears to be writeable and we have something ready to send.
1496  */
1497 static int try_write(struct ceph_connection *con)
1498 {
1499         struct ceph_messenger *msgr = con->msgr;
1500         int ret = 1;
1501
1502         dout("try_write start %p state %lu nref %d\n", con, con->state,
1503              atomic_read(&con->nref));
1504
1505         mutex_lock(&con->mutex);
1506 more:
1507         dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
1508
1509         /* open the socket first? */
1510         if (con->sock == NULL) {
1511                 /*
1512                  * if we were STANDBY and are reconnecting _this_
1513                  * connection, bump connect_seq now.  Always bump
1514                  * global_seq.
1515                  */
1516                 if (test_and_clear_bit(STANDBY, &con->state))
1517                         con->connect_seq++;
1518
1519                 prepare_write_banner(msgr, con);
1520                 prepare_write_connect(msgr, con, 1);
1521                 prepare_read_banner(con);
1522                 set_bit(CONNECTING, &con->state);
1523                 clear_bit(NEGOTIATING, &con->state);
1524
1525                 BUG_ON(con->in_msg);
1526                 con->in_tag = CEPH_MSGR_TAG_READY;
1527                 dout("try_write initiating connect on %p new state %lu\n",
1528                      con, con->state);
1529                 con->sock = ceph_tcp_connect(con);
1530                 if (IS_ERR(con->sock)) {
1531                         con->sock = NULL;
1532                         con->error_msg = "connect error";
1533                         ret = -1;
1534                         goto out;
1535                 }
1536         }
1537
1538 more_kvec:
1539         /* kvec data queued? */
1540         if (con->out_skip) {
1541                 ret = write_partial_skip(con);
1542                 if (ret <= 0)
1543                         goto done;
1544                 if (ret < 0) {
1545                         dout("try_write write_partial_skip err %d\n", ret);
1546                         goto done;
1547                 }
1548         }
1549         if (con->out_kvec_left) {
1550                 ret = write_partial_kvec(con);
1551                 if (ret <= 0)
1552                         goto done;
1553         }
1554
1555         /* msg pages? */
1556         if (con->out_msg) {
1557                 if (con->out_msg_done) {
1558                         ceph_msg_put(con->out_msg);
1559                         con->out_msg = NULL;   /* we're done with this one */
1560                         goto do_next;
1561                 }
1562
1563                 ret = write_partial_msg_pages(con);
1564                 if (ret == 1)
1565                         goto more_kvec;  /* we need to send the footer, too! */
1566                 if (ret == 0)
1567                         goto done;
1568                 if (ret < 0) {
1569                         dout("try_write write_partial_msg_pages err %d\n",
1570                              ret);
1571                         goto done;
1572                 }
1573         }
1574
1575 do_next:
1576         if (!test_bit(CONNECTING, &con->state)) {
1577                 /* is anything else pending? */
1578                 if (!list_empty(&con->out_queue)) {
1579                         prepare_write_message(con);
1580                         goto more;
1581                 }
1582                 if (con->in_seq > con->in_seq_acked) {
1583                         prepare_write_ack(con);
1584                         goto more;
1585                 }
1586                 if (test_and_clear_bit(KEEPALIVE_PENDING, &con->state)) {
1587                         prepare_write_keepalive(con);
1588                         goto more;
1589                 }
1590         }
1591
1592         /* Nothing to do! */
1593         clear_bit(WRITE_PENDING, &con->state);
1594         dout("try_write nothing else to write.\n");
1595 done:
1596         ret = 0;
1597 out:
1598         mutex_unlock(&con->mutex);
1599         dout("try_write done on %p\n", con);
1600         return ret;
1601 }
1602
1603
1604
1605 /*
1606  * Read what we can from the socket.
1607  */
1608 static int try_read(struct ceph_connection *con)
1609 {
1610         struct ceph_messenger *msgr;
1611         int ret = -1;
1612
1613         if (!con->sock)
1614                 return 0;
1615
1616         if (test_bit(STANDBY, &con->state))
1617                 return 0;
1618
1619         dout("try_read start on %p\n", con);
1620         msgr = con->msgr;
1621
1622         mutex_lock(&con->mutex);
1623
1624 more:
1625         dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,
1626              con->in_base_pos);
1627         if (test_bit(CONNECTING, &con->state)) {
1628                 if (!test_bit(NEGOTIATING, &con->state)) {
1629                         dout("try_read connecting\n");
1630                         ret = read_partial_banner(con);
1631                         if (ret <= 0)
1632                                 goto done;
1633                         if (process_banner(con) < 0) {
1634                                 ret = -1;
1635                                 goto out;
1636                         }
1637                 }
1638                 ret = read_partial_connect(con);
1639                 if (ret <= 0)
1640                         goto done;
1641                 if (process_connect(con) < 0) {
1642                         ret = -1;
1643                         goto out;
1644                 }
1645                 goto more;
1646         }
1647
1648         if (con->in_base_pos < 0) {
1649                 /*
1650                  * skipping + discarding content.
1651                  *
1652                  * FIXME: there must be a better way to do this!
1653                  */
1654                 static char buf[1024];
1655                 int skip = min(1024, -con->in_base_pos);
1656                 dout("skipping %d / %d bytes\n", skip, -con->in_base_pos);
1657                 ret = ceph_tcp_recvmsg(con->sock, buf, skip);
1658                 if (ret <= 0)
1659                         goto done;
1660                 con->in_base_pos += ret;
1661                 if (con->in_base_pos)
1662                         goto more;
1663         }
1664         if (con->in_tag == CEPH_MSGR_TAG_READY) {
1665                 /*
1666                  * what's next?
1667                  */
1668                 ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
1669                 if (ret <= 0)
1670                         goto done;
1671                 dout("try_read got tag %d\n", (int)con->in_tag);
1672                 switch (con->in_tag) {
1673                 case CEPH_MSGR_TAG_MSG:
1674                         prepare_read_message(con);
1675                         break;
1676                 case CEPH_MSGR_TAG_ACK:
1677                         prepare_read_ack(con);
1678                         break;
1679                 case CEPH_MSGR_TAG_CLOSE:
1680                         set_bit(CLOSED, &con->state);   /* fixme */
1681                         goto done;
1682                 default:
1683                         goto bad_tag;
1684                 }
1685         }
1686         if (con->in_tag == CEPH_MSGR_TAG_MSG) {
1687                 ret = read_partial_message(con);
1688                 if (ret <= 0) {
1689                         switch (ret) {
1690                         case -EBADMSG:
1691                                 con->error_msg = "bad crc";
1692                                 ret = -EIO;
1693                                 goto out;
1694                         case -EIO:
1695                                 con->error_msg = "io error";
1696                                 goto out;
1697                         default:
1698                                 goto done;
1699                         }
1700                 }
1701                 if (con->in_tag == CEPH_MSGR_TAG_READY)
1702                         goto more;
1703                 process_message(con);
1704                 goto more;
1705         }
1706         if (con->in_tag == CEPH_MSGR_TAG_ACK) {
1707                 ret = read_partial_ack(con);
1708                 if (ret <= 0)
1709                         goto done;
1710                 process_ack(con);
1711                 goto more;
1712         }
1713
1714 done:
1715         ret = 0;
1716 out:
1717         mutex_unlock(&con->mutex);
1718         dout("try_read done on %p\n", con);
1719         return ret;
1720
1721 bad_tag:
1722         pr_err("try_read bad con->in_tag = %d\n", (int)con->in_tag);
1723         con->error_msg = "protocol error, garbage tag";
1724         ret = -1;
1725         goto out;
1726 }
1727
1728
1729 /*
1730  * Atomically queue work on a connection.  Bump @con reference to
1731  * avoid races with connection teardown.
1732  *
1733  * There is some trickery going on with QUEUED and BUSY because we
1734  * only want a _single_ thread operating on each connection at any
1735  * point in time, but we want to use all available CPUs.
1736  *
1737  * The worker thread only proceeds if it can atomically set BUSY.  It
1738  * clears QUEUED and does it's thing.  When it thinks it's done, it
1739  * clears BUSY, then rechecks QUEUED.. if it's set again, it loops
1740  * (tries again to set BUSY).
1741  *
1742  * To queue work, we first set QUEUED, _then_ if BUSY isn't set, we
1743  * try to queue work.  If that fails (work is already queued, or BUSY)
1744  * we give up (work also already being done or is queued) but leave QUEUED
1745  * set so that the worker thread will loop if necessary.
1746  */
1747 static void queue_con(struct ceph_connection *con)
1748 {
1749         if (test_bit(DEAD, &con->state)) {
1750                 dout("queue_con %p ignoring: DEAD\n",
1751                      con);
1752                 return;
1753         }
1754
1755         if (!con->ops->get(con)) {
1756                 dout("queue_con %p ref count 0\n", con);
1757                 return;
1758         }
1759
1760         set_bit(QUEUED, &con->state);
1761         if (test_bit(BUSY, &con->state)) {
1762                 dout("queue_con %p - already BUSY\n", con);
1763                 con->ops->put(con);
1764         } else if (!queue_work(ceph_msgr_wq, &con->work.work)) {
1765                 dout("queue_con %p - already queued\n", con);
1766                 con->ops->put(con);
1767         } else {
1768                 dout("queue_con %p\n", con);
1769         }
1770 }
1771
1772 /*
1773  * Do some work on a connection.  Drop a connection ref when we're done.
1774  */
1775 static void con_work(struct work_struct *work)
1776 {
1777         struct ceph_connection *con = container_of(work, struct ceph_connection,
1778                                                    work.work);
1779         int backoff = 0;
1780
1781 more:
1782         if (test_and_set_bit(BUSY, &con->state) != 0) {
1783                 dout("con_work %p BUSY already set\n", con);
1784                 goto out;
1785         }
1786         dout("con_work %p start, clearing QUEUED\n", con);
1787         clear_bit(QUEUED, &con->state);
1788
1789         if (test_bit(CLOSED, &con->state)) { /* e.g. if we are replaced */
1790                 dout("con_work CLOSED\n");
1791                 con_close_socket(con);
1792                 goto done;
1793         }
1794         if (test_and_clear_bit(OPENING, &con->state)) {
1795                 /* reopen w/ new peer */
1796                 dout("con_work OPENING\n");
1797                 con_close_socket(con);
1798         }
1799
1800         if (test_and_clear_bit(SOCK_CLOSED, &con->state) ||
1801             try_read(con) < 0 ||
1802             try_write(con) < 0) {
1803                 backoff = 1;
1804                 ceph_fault(con);     /* error/fault path */
1805         }
1806
1807 done:
1808         clear_bit(BUSY, &con->state);
1809         dout("con->state=%lu\n", con->state);
1810         if (test_bit(QUEUED, &con->state)) {
1811                 if (!backoff) {
1812                         dout("con_work %p QUEUED reset, looping\n", con);
1813                         goto more;
1814                 }
1815                 dout("con_work %p QUEUED reset, but just faulted\n", con);
1816                 clear_bit(QUEUED, &con->state);
1817         }
1818         dout("con_work %p done\n", con);
1819
1820 out:
1821         con->ops->put(con);
1822 }
1823
1824
1825 /*
1826  * Generic error/fault handler.  A retry mechanism is used with
1827  * exponential backoff
1828  */
1829 static void ceph_fault(struct ceph_connection *con)
1830 {
1831         pr_err("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
1832                pr_addr(&con->peer_addr.in_addr), con->error_msg);
1833         dout("fault %p state %lu to peer %s\n",
1834              con, con->state, pr_addr(&con->peer_addr.in_addr));
1835
1836         if (test_bit(LOSSYTX, &con->state)) {
1837                 dout("fault on LOSSYTX channel\n");
1838                 goto out;
1839         }
1840
1841         clear_bit(BUSY, &con->state);  /* to avoid an improbable race */
1842
1843         mutex_lock(&con->mutex);
1844
1845         con_close_socket(con);
1846
1847         if (con->in_msg) {
1848                 ceph_msg_put(con->in_msg);
1849                 con->in_msg = NULL;
1850         }
1851
1852         /* If there are no messages in the queue, place the connection
1853          * in a STANDBY state (i.e., don't try to reconnect just yet). */
1854         if (list_empty(&con->out_queue) && !con->out_keepalive_pending) {
1855                 dout("fault setting STANDBY\n");
1856                 set_bit(STANDBY, &con->state);
1857                 mutex_unlock(&con->mutex);
1858                 goto out;
1859         }
1860
1861         /* Requeue anything that hasn't been acked, and retry after a
1862          * delay. */
1863         list_splice_init(&con->out_sent, &con->out_queue);
1864
1865         if (con->delay == 0)
1866                 con->delay = BASE_DELAY_INTERVAL;
1867         else if (con->delay < MAX_DELAY_INTERVAL)
1868                 con->delay *= 2;
1869
1870         mutex_unlock(&con->mutex);
1871
1872         /* explicitly schedule work to try to reconnect again later. */
1873         dout("fault queueing %p delay %lu\n", con, con->delay);
1874         con->ops->get(con);
1875         if (queue_delayed_work(ceph_msgr_wq, &con->work,
1876                                round_jiffies_relative(con->delay)) == 0)
1877                 con->ops->put(con);
1878
1879 out:
1880         if (con->ops->fault)
1881                 con->ops->fault(con);
1882 }
1883
1884
1885
1886 /*
1887  * create a new messenger instance
1888  */
1889 struct ceph_messenger *ceph_messenger_create(struct ceph_entity_addr *myaddr)
1890 {
1891         struct ceph_messenger *msgr;
1892
1893         msgr = kzalloc(sizeof(*msgr), GFP_KERNEL);
1894         if (msgr == NULL)
1895                 return ERR_PTR(-ENOMEM);
1896
1897         spin_lock_init(&msgr->global_seq_lock);
1898
1899         /* the zero page is needed if a request is "canceled" while the message
1900          * is being written over the socket */
1901         msgr->zero_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
1902         if (!msgr->zero_page) {
1903                 kfree(msgr);
1904                 return ERR_PTR(-ENOMEM);
1905         }
1906         kmap(msgr->zero_page);
1907
1908         if (myaddr)
1909                 msgr->inst.addr = *myaddr;
1910
1911         /* select a random nonce */
1912         get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
1913         encode_my_addr(msgr);
1914
1915         dout("messenger_create %p\n", msgr);
1916         return msgr;
1917 }
1918
1919 void ceph_messenger_destroy(struct ceph_messenger *msgr)
1920 {
1921         dout("destroy %p\n", msgr);
1922         kunmap(msgr->zero_page);
1923         __free_page(msgr->zero_page);
1924         kfree(msgr);
1925         dout("destroyed messenger %p\n", msgr);
1926 }
1927
1928 /*
1929  * Queue up an outgoing message on the given connection.
1930  */
1931 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
1932 {
1933         if (test_bit(CLOSED, &con->state)) {
1934                 dout("con_send %p closed, dropping %p\n", con, msg);
1935                 ceph_msg_put(msg);
1936                 return;
1937         }
1938
1939         /* set src+dst */
1940         msg->hdr.src.name = con->msgr->inst.name;
1941         msg->hdr.src.addr = con->msgr->my_enc_addr;
1942         msg->hdr.orig_src = msg->hdr.src;
1943
1944         /* queue */
1945         mutex_lock(&con->mutex);
1946         BUG_ON(!list_empty(&msg->list_head));
1947         list_add_tail(&msg->list_head, &con->out_queue);
1948         dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
1949              ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
1950              ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
1951              le32_to_cpu(msg->hdr.front_len),
1952              le32_to_cpu(msg->hdr.middle_len),
1953              le32_to_cpu(msg->hdr.data_len));
1954         mutex_unlock(&con->mutex);
1955
1956         /* if there wasn't anything waiting to send before, queue
1957          * new work */
1958         if (test_and_set_bit(WRITE_PENDING, &con->state) == 0)
1959                 queue_con(con);
1960 }
1961
1962 /*
1963  * Revoke a message that was previously queued for send
1964  */
1965 void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg)
1966 {
1967         mutex_lock(&con->mutex);
1968         if (!list_empty(&msg->list_head)) {
1969                 dout("con_revoke %p msg %p\n", con, msg);
1970                 list_del_init(&msg->list_head);
1971                 ceph_msg_put(msg);
1972                 msg->hdr.seq = 0;
1973                 if (con->out_msg == msg) {
1974                         ceph_msg_put(con->out_msg);
1975                         con->out_msg = NULL;
1976                 }
1977                 if (con->out_kvec_is_msg) {
1978                         con->out_skip = con->out_kvec_bytes;
1979                         con->out_kvec_is_msg = false;
1980                 }
1981         } else {
1982                 dout("con_revoke %p msg %p - not queued (sent?)\n", con, msg);
1983         }
1984         mutex_unlock(&con->mutex);
1985 }
1986
1987 /*
1988  * Revoke a message that we may be reading data into
1989  */
1990 void ceph_con_revoke_message(struct ceph_connection *con, struct ceph_msg *msg)
1991 {
1992         mutex_lock(&con->mutex);
1993         if (con->in_msg && con->in_msg == msg) {
1994                 unsigned front_len = le32_to_cpu(con->in_hdr.front_len);
1995                 unsigned middle_len = le32_to_cpu(con->in_hdr.middle_len);
1996                 unsigned data_len = le32_to_cpu(con->in_hdr.data_len);
1997
1998                 /* skip rest of message */
1999                 dout("con_revoke_pages %p msg %p revoked\n", con, msg);
2000                         con->in_base_pos = con->in_base_pos -
2001                                 sizeof(struct ceph_msg_header) -
2002                                 front_len -
2003                                 middle_len -
2004                                 data_len -
2005                                 sizeof(struct ceph_msg_footer);
2006                 ceph_msg_put(con->in_msg);
2007                 con->in_msg = NULL;
2008                 con->in_tag = CEPH_MSGR_TAG_READY;
2009         } else {
2010                 dout("con_revoke_pages %p msg %p pages %p no-op\n",
2011                      con, con->in_msg, msg);
2012         }
2013         mutex_unlock(&con->mutex);
2014 }
2015
2016 /*
2017  * Queue a keepalive byte to ensure the tcp connection is alive.
2018  */
2019 void ceph_con_keepalive(struct ceph_connection *con)
2020 {
2021         if (test_and_set_bit(KEEPALIVE_PENDING, &con->state) == 0 &&
2022             test_and_set_bit(WRITE_PENDING, &con->state) == 0)
2023                 queue_con(con);
2024 }
2025
2026
2027 /*
2028  * construct a new message with given type, size
2029  * the new msg has a ref count of 1.
2030  */
2031 struct ceph_msg *ceph_msg_new(int type, int front_len,
2032                               int page_len, int page_off, struct page **pages)
2033 {
2034         struct ceph_msg *m;
2035
2036         m = kmalloc(sizeof(*m), GFP_NOFS);
2037         if (m == NULL)
2038                 goto out;
2039         kref_init(&m->kref);
2040         INIT_LIST_HEAD(&m->list_head);
2041
2042         m->hdr.type = cpu_to_le16(type);
2043         m->hdr.front_len = cpu_to_le32(front_len);
2044         m->hdr.middle_len = 0;
2045         m->hdr.data_len = cpu_to_le32(page_len);
2046         m->hdr.data_off = cpu_to_le16(page_off);
2047         m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
2048         m->footer.front_crc = 0;
2049         m->footer.middle_crc = 0;
2050         m->footer.data_crc = 0;
2051         m->front_max = front_len;
2052         m->front_is_vmalloc = false;
2053         m->more_to_follow = false;
2054         m->pool = NULL;
2055
2056         /* front */
2057         if (front_len) {
2058                 if (front_len > PAGE_CACHE_SIZE) {
2059                         m->front.iov_base = __vmalloc(front_len, GFP_NOFS,
2060                                                       PAGE_KERNEL);
2061                         m->front_is_vmalloc = true;
2062                 } else {
2063                         m->front.iov_base = kmalloc(front_len, GFP_NOFS);
2064                 }
2065                 if (m->front.iov_base == NULL) {
2066                         pr_err("msg_new can't allocate %d bytes\n",
2067                              front_len);
2068                         goto out2;
2069                 }
2070         } else {
2071                 m->front.iov_base = NULL;
2072         }
2073         m->front.iov_len = front_len;
2074
2075         /* middle */
2076         m->middle = NULL;
2077
2078         /* data */
2079         m->nr_pages = calc_pages_for(page_off, page_len);
2080         m->pages = pages;
2081         m->pagelist = NULL;
2082
2083         dout("ceph_msg_new %p page %d~%d -> %d\n", m, page_off, page_len,
2084              m->nr_pages);
2085         return m;
2086
2087 out2:
2088         ceph_msg_put(m);
2089 out:
2090         pr_err("msg_new can't create type %d len %d\n", type, front_len);
2091         return ERR_PTR(-ENOMEM);
2092 }
2093
2094 /*
2095  * Allocate "middle" portion of a message, if it is needed and wasn't
2096  * allocated by alloc_msg.  This allows us to read a small fixed-size
2097  * per-type header in the front and then gracefully fail (i.e.,
2098  * propagate the error to the caller based on info in the front) when
2099  * the middle is too large.
2100  */
2101 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
2102 {
2103         int type = le16_to_cpu(msg->hdr.type);
2104         int middle_len = le32_to_cpu(msg->hdr.middle_len);
2105
2106         dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
2107              ceph_msg_type_name(type), middle_len);
2108         BUG_ON(!middle_len);
2109         BUG_ON(msg->middle);
2110
2111         msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
2112         if (!msg->middle)
2113                 return -ENOMEM;
2114         return 0;
2115 }
2116
2117 /*
2118  * Generic message allocator, for incoming messages.
2119  */
2120 static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
2121                                 struct ceph_msg_header *hdr,
2122                                 int *skip)
2123 {
2124         int type = le16_to_cpu(hdr->type);
2125         int front_len = le32_to_cpu(hdr->front_len);
2126         int middle_len = le32_to_cpu(hdr->middle_len);
2127         struct ceph_msg *msg = NULL;
2128         int ret;
2129
2130         if (con->ops->alloc_msg) {
2131                 mutex_unlock(&con->mutex);
2132                 msg = con->ops->alloc_msg(con, hdr, skip);
2133                 mutex_lock(&con->mutex);
2134                 if (IS_ERR(msg))
2135                         return msg;
2136
2137                 if (*skip)
2138                         return NULL;
2139         }
2140         if (!msg) {
2141                 *skip = 0;
2142                 msg = ceph_msg_new(type, front_len, 0, 0, NULL);
2143                 if (!msg) {
2144                         pr_err("unable to allocate msg type %d len %d\n",
2145                                type, front_len);
2146                         return ERR_PTR(-ENOMEM);
2147                 }
2148         }
2149         memcpy(&msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
2150
2151         if (middle_len) {
2152                 ret = ceph_alloc_middle(con, msg);
2153
2154                 if (ret < 0) {
2155                         ceph_msg_put(msg);
2156                         return msg;
2157                 }
2158         }
2159
2160         return msg;
2161 }
2162
2163
2164 /*
2165  * Free a generically kmalloc'd message.
2166  */
2167 void ceph_msg_kfree(struct ceph_msg *m)
2168 {
2169         dout("msg_kfree %p\n", m);
2170         if (m->front_is_vmalloc)
2171                 vfree(m->front.iov_base);
2172         else
2173                 kfree(m->front.iov_base);
2174         kfree(m);
2175 }
2176
2177 /*
2178  * Drop a msg ref.  Destroy as needed.
2179  */
2180 void ceph_msg_last_put(struct kref *kref)
2181 {
2182         struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
2183
2184         dout("ceph_msg_put last one on %p\n", m);
2185         WARN_ON(!list_empty(&m->list_head));
2186
2187         /* drop middle, data, if any */
2188         if (m->middle) {
2189                 ceph_buffer_put(m->middle);
2190                 m->middle = NULL;
2191         }
2192         m->nr_pages = 0;
2193         m->pages = NULL;
2194
2195         if (m->pagelist) {
2196                 ceph_pagelist_release(m->pagelist);
2197                 kfree(m->pagelist);
2198                 m->pagelist = NULL;
2199         }
2200
2201         if (m->pool)
2202                 ceph_msgpool_put(m->pool, m);
2203         else
2204                 ceph_msg_kfree(m);
2205 }
2206
2207 void ceph_msg_dump(struct ceph_msg *msg)
2208 {
2209         pr_debug("msg_dump %p (front_max %d nr_pages %d)\n", msg,
2210                  msg->front_max, msg->nr_pages);
2211         print_hex_dump(KERN_DEBUG, "header: ",
2212                        DUMP_PREFIX_OFFSET, 16, 1,
2213                        &msg->hdr, sizeof(msg->hdr), true);
2214         print_hex_dump(KERN_DEBUG, " front: ",
2215                        DUMP_PREFIX_OFFSET, 16, 1,
2216                        msg->front.iov_base, msg->front.iov_len, true);
2217         if (msg->middle)
2218                 print_hex_dump(KERN_DEBUG, "middle: ",
2219                                DUMP_PREFIX_OFFSET, 16, 1,
2220                                msg->middle->vec.iov_base,
2221                                msg->middle->vec.iov_len, true);
2222         print_hex_dump(KERN_DEBUG, "footer: ",
2223                        DUMP_PREFIX_OFFSET, 16, 1,
2224                        &msg->footer, sizeof(msg->footer), true);
2225 }