LXR linux/include/linux/ceph/messenger.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __FS_CEPH_MESSENGER_H
   3#define __FS_CEPH_MESSENGER_H
   4
   5#include <linux/bvec.h>
   6#include <linux/crypto.h>
   7#include <linux/kref.h>
   8#include <linux/mutex.h>
   9#include <linux/net.h>
  10#include <linux/radix-tree.h>
  11#include <linux/uio.h>
  12#include <linux/workqueue.h>
  13#include <net/net_namespace.h>
  14
  15#include <linux/ceph/types.h>
  16#include <linux/ceph/buffer.h>
  17
  18struct ceph_msg;
  19struct ceph_connection;
  20
  21/*
  22 * Ceph defines these callbacks for handling connection events.
  23 */
  24struct ceph_connection_operations {
  25        struct ceph_connection *(*get)(struct ceph_connection *);
  26        void (*put)(struct ceph_connection *);
  27
  28        /* handle an incoming message. */
  29        void (*dispatch) (struct ceph_connection *con, struct ceph_msg *m);
  30
  31        /* authorize an outgoing connection */
  32        struct ceph_auth_handshake *(*get_authorizer) (
  33                                struct ceph_connection *con,
  34                               int *proto, int force_new);
  35        int (*add_authorizer_challenge)(struct ceph_connection *con,
  36                                        void *challenge_buf,
  37                                        int challenge_buf_len);
  38        int (*verify_authorizer_reply) (struct ceph_connection *con);
  39        int (*invalidate_authorizer)(struct ceph_connection *con);
  40
  41        /* there was some error on the socket (disconnect, whatever) */
  42        void (*fault) (struct ceph_connection *con);
  43
  44        /* a remote host as terminated a message exchange session, and messages
  45         * we sent (or they tried to send us) may be lost. */
  46        void (*peer_reset) (struct ceph_connection *con);
  47
  48        struct ceph_msg * (*alloc_msg) (struct ceph_connection *con,
  49                                        struct ceph_msg_header *hdr,
  50                                        int *skip);
  51
  52        void (*reencode_message) (struct ceph_msg *msg);
  53
  54        int (*sign_message) (struct ceph_msg *msg);
  55        int (*check_message_signature) (struct ceph_msg *msg);
  56
  57        /* msgr2 authentication exchange */
  58        int (*get_auth_request)(struct ceph_connection *con,
  59                                void *buf, int *buf_len,
  60                                void **authorizer, int *authorizer_len);
  61        int (*handle_auth_reply_more)(struct ceph_connection *con,
  62                                      void *reply, int reply_len,
  63                                      void *buf, int *buf_len,
  64                                      void **authorizer, int *authorizer_len);
  65        int (*handle_auth_done)(struct ceph_connection *con,
  66                                u64 global_id, void *reply, int reply_len,
  67                                u8 *session_key, int *session_key_len,
  68                                u8 *con_secret, int *con_secret_len);
  69        int (*handle_auth_bad_method)(struct ceph_connection *con,
  70                                      int used_proto, int result,
  71                                      const int *allowed_protos, int proto_cnt,
  72                                      const int *allowed_modes, int mode_cnt);
  73};
  74
  75/* use format string %s%lld */
  76#define ENTITY_NAME(n) ceph_entity_type_name((n).type), le64_to_cpu((n).num)
  77
  78struct ceph_messenger {
  79        struct ceph_entity_inst inst;    /* my name+address */
  80        struct ceph_entity_addr my_enc_addr;
  81
  82        atomic_t stopping;
  83        possible_net_t net;
  84
  85        /*
  86         * the global_seq counts connections i (attempt to) initiate
  87         * in order to disambiguate certain connect race conditions.
  88         */
  89        u32 global_seq;
  90        spinlock_t global_seq_lock;
  91};
  92
  93enum ceph_msg_data_type {
  94        CEPH_MSG_DATA_NONE,     /* message contains no data payload */
  95        CEPH_MSG_DATA_PAGES,    /* data source/destination is a page array */
  96        CEPH_MSG_DATA_PAGELIST, /* data source/destination is a pagelist */
  97#ifdef CONFIG_BLOCK
  98        CEPH_MSG_DATA_BIO,      /* data source/destination is a bio list */
  99#endif /* CONFIG_BLOCK */
 100        CEPH_MSG_DATA_BVECS,    /* data source/destination is a bio_vec array */
 101};
 102
 103#ifdef CONFIG_BLOCK
 104
 105struct ceph_bio_iter {
 106        struct bio *bio;
 107        struct bvec_iter iter;
 108};
 109
 110#define __ceph_bio_iter_advance_step(it, n, STEP) do {                        \
 111        unsigned int __n = (n), __cur_n;                                      \
 112                                                                              \
 113        while (__n) {                                                         \
 114                BUG_ON(!(it)->iter.bi_size);                                  \
 115                __cur_n = min((it)->iter.bi_size, __n);                       \
 116                (void)(STEP);                                                 \
 117                bio_advance_iter((it)->bio, &(it)->iter, __cur_n);            \
 118                if (!(it)->iter.bi_size && (it)->bio->bi_next) {              \
 119                        dout("__ceph_bio_iter_advance_step next bio\n");      \
 120                        (it)->bio = (it)->bio->bi_next;                       \
 121                        (it)->iter = (it)->bio->bi_iter;                      \
 122                }                                                             \
 123                __n -= __cur_n;                                               \
 124        }                                                                     \
 125} while (0)
 126
 127/*
 128 * Advance @it by @n bytes.
 129 */
 130#define ceph_bio_iter_advance(it, n)                                          \
 131        __ceph_bio_iter_advance_step(it, n, 0)
 132
 133/*
 134 * Advance @it by @n bytes, executing BVEC_STEP for each bio_vec.
 135 */
 136#define ceph_bio_iter_advance_step(it, n, BVEC_STEP)                          \
 137        __ceph_bio_iter_advance_step(it, n, ({                                \
 138                struct bio_vec bv;                                            \
 139                struct bvec_iter __cur_iter;                                  \
 140                                                                              \
 141                __cur_iter = (it)->iter;                                      \
 142                __cur_iter.bi_size = __cur_n;                                 \
 143                __bio_for_each_segment(bv, (it)->bio, __cur_iter, __cur_iter) \
 144                        (void)(BVEC_STEP);                                    \
 145        }))
 146
 147#endif /* CONFIG_BLOCK */
 148
 149struct ceph_bvec_iter {
 150        struct bio_vec *bvecs;
 151        struct bvec_iter iter;
 152};
 153
 154#define __ceph_bvec_iter_advance_step(it, n, STEP) do {                       \
 155        BUG_ON((n) > (it)->iter.bi_size);                                     \
 156        (void)(STEP);                                                         \
 157        bvec_iter_advance((it)->bvecs, &(it)->iter, (n));                     \
 158} while (0)
 159
 160/*
 161 * Advance @it by @n bytes.
 162 */
 163#define ceph_bvec_iter_advance(it, n)                                         \
 164        __ceph_bvec_iter_advance_step(it, n, 0)
 165
 166/*
 167 * Advance @it by @n bytes, executing BVEC_STEP for each bio_vec.
 168 */
 169#define ceph_bvec_iter_advance_step(it, n, BVEC_STEP)                         \
 170        __ceph_bvec_iter_advance_step(it, n, ({                               \
 171                struct bio_vec bv;                                            \
 172                struct bvec_iter __cur_iter;                                  \
 173                                                                              \
 174                __cur_iter = (it)->iter;                                      \
 175                __cur_iter.bi_size = (n);                                     \
 176                for_each_bvec(bv, (it)->bvecs, __cur_iter, __cur_iter)        \
 177                        (void)(BVEC_STEP);                                    \
 178        }))
 179
 180#define ceph_bvec_iter_shorten(it, n) do {                                    \
 181        BUG_ON((n) > (it)->iter.bi_size);                                     \
 182        (it)->iter.bi_size = (n);                                             \
 183} while (0)
 184
 185struct ceph_msg_data {
 186        enum ceph_msg_data_type         type;
 187        union {
 188#ifdef CONFIG_BLOCK
 189                struct {
 190                        struct ceph_bio_iter    bio_pos;
 191                        u32                     bio_length;
 192                };
 193#endif /* CONFIG_BLOCK */
 194                struct ceph_bvec_iter   bvec_pos;
 195                struct {
 196                        struct page     **pages;
 197                        size_t          length;         /* total # bytes */
 198                        unsigned int    alignment;      /* first page */
 199                        bool            own_pages;
 200                };
 201                struct ceph_pagelist    *pagelist;
 202        };
 203};
 204
 205struct ceph_msg_data_cursor {
 206        size_t                  total_resid;    /* across all data items */
 207
 208        struct ceph_msg_data    *data;          /* current data item */
 209        size_t                  resid;          /* bytes not yet consumed */
 210        bool                    last_piece;     /* current is last piece */
 211        bool                    need_crc;       /* crc update needed */
 212        union {
 213#ifdef CONFIG_BLOCK
 214                struct ceph_bio_iter    bio_iter;
 215#endif /* CONFIG_BLOCK */
 216                struct bvec_iter        bvec_iter;
 217                struct {                                /* pages */
 218                        unsigned int    page_offset;    /* offset in page */
 219                        unsigned short  page_index;     /* index in array */
 220                        unsigned short  page_count;     /* pages in array */
 221                };
 222                struct {                                /* pagelist */
 223                        struct page     *page;          /* page from list */
 224                        size_t          offset;         /* bytes from list */
 225                };
 226        };
 227};
 228
 229/*
 230 * a single message.  it contains a header (src, dest, message type, etc.),
 231 * footer (crc values, mainly), a "front" message body, and possibly a
 232 * data payload (stored in some number of pages).
 233 */
 234struct ceph_msg {
 235        struct ceph_msg_header hdr;     /* header */
 236        union {
 237                struct ceph_msg_footer footer;          /* footer */
 238                struct ceph_msg_footer_old old_footer;  /* old format footer */
 239        };
 240        struct kvec front;              /* unaligned blobs of message */
 241        struct ceph_buffer *middle;
 242
 243        size_t                          data_length;
 244        struct ceph_msg_data            *data;
 245        int                             num_data_items;
 246        int                             max_data_items;
 247        struct ceph_msg_data_cursor     cursor;
 248
 249        struct ceph_connection *con;
 250        struct list_head list_head;     /* links for connection lists */
 251
 252        struct kref kref;
 253        bool more_to_follow;
 254        bool needs_out_seq;
 255        int front_alloc_len;
 256
 257        struct ceph_msgpool *pool;
 258};
 259
 260/*
 261 * connection states
 262 */
 263#define CEPH_CON_S_CLOSED               1
 264#define CEPH_CON_S_PREOPEN              2
 265#define CEPH_CON_S_V1_BANNER            3
 266#define CEPH_CON_S_V1_CONNECT_MSG       4
 267#define CEPH_CON_S_V2_BANNER_PREFIX     5
 268#define CEPH_CON_S_V2_BANNER_PAYLOAD    6
 269#define CEPH_CON_S_V2_HELLO             7
 270#define CEPH_CON_S_V2_AUTH              8
 271#define CEPH_CON_S_V2_AUTH_SIGNATURE    9
 272#define CEPH_CON_S_V2_SESSION_CONNECT   10
 273#define CEPH_CON_S_V2_SESSION_RECONNECT 11
 274#define CEPH_CON_S_OPEN                 12
 275#define CEPH_CON_S_STANDBY              13
 276
 277/*
 278 * ceph_connection flag bits
 279 */
 280#define CEPH_CON_F_LOSSYTX              0  /* we can close channel or drop
 281                                              messages on errors */
 282#define CEPH_CON_F_KEEPALIVE_PENDING    1  /* we need to send a keepalive */
 283#define CEPH_CON_F_WRITE_PENDING        2  /* we have data ready to send */
 284#define CEPH_CON_F_SOCK_CLOSED          3  /* socket state changed to closed */
 285#define CEPH_CON_F_BACKOFF              4  /* need to retry queuing delayed
 286                                              work */
 287
 288/* ceph connection fault delay defaults, for exponential backoff */
 289#define BASE_DELAY_INTERVAL     (HZ / 4)
 290#define MAX_DELAY_INTERVAL      (15 * HZ)
 291
 292struct ceph_connection_v1_info {
 293        struct kvec out_kvec[8],         /* sending header/footer data */
 294                *out_kvec_cur;
 295        int out_kvec_left;   /* kvec's left in out_kvec */
 296        int out_skip;        /* skip this many bytes */
 297        int out_kvec_bytes;  /* total bytes left */
 298        bool out_more;       /* there is more data after the kvecs */
 299        bool out_msg_done;
 300
 301        struct ceph_auth_handshake *auth;
 302        int auth_retry;       /* true if we need a newer authorizer */
 303
 304        /* connection negotiation temps */
 305        u8 in_banner[CEPH_BANNER_MAX_LEN];
 306        struct ceph_entity_addr actual_peer_addr;
 307        struct ceph_entity_addr peer_addr_for_me;
 308        struct ceph_msg_connect out_connect;
 309        struct ceph_msg_connect_reply in_reply;
 310
 311        int in_base_pos;     /* bytes read */
 312
 313        /* message in temps */
 314        u8 in_tag;           /* protocol control byte */
 315        struct ceph_msg_header in_hdr;
 316        __le64 in_temp_ack;  /* for reading an ack */
 317
 318        /* message out temps */
 319        struct ceph_msg_header out_hdr;
 320        __le64 out_temp_ack;  /* for writing an ack */
 321        struct ceph_timespec out_temp_keepalive2;  /* for writing keepalive2
 322                                                      stamp */
 323
 324        u32 connect_seq;      /* identify the most recent connection
 325                                 attempt for this session */
 326        u32 peer_global_seq;  /* peer's global seq for this connection */
 327};
 328
 329#define CEPH_CRC_LEN                    4
 330#define CEPH_GCM_KEY_LEN                16
 331#define CEPH_GCM_IV_LEN                 sizeof(struct ceph_gcm_nonce)
 332#define CEPH_GCM_BLOCK_LEN              16
 333#define CEPH_GCM_TAG_LEN                16
 334
 335#define CEPH_PREAMBLE_LEN               32
 336#define CEPH_PREAMBLE_INLINE_LEN        48
 337#define CEPH_PREAMBLE_PLAIN_LEN         CEPH_PREAMBLE_LEN
 338#define CEPH_PREAMBLE_SECURE_LEN        (CEPH_PREAMBLE_LEN +            \
 339                                         CEPH_PREAMBLE_INLINE_LEN +     \
 340                                         CEPH_GCM_TAG_LEN)
 341#define CEPH_EPILOGUE_PLAIN_LEN         (1 + 3 * CEPH_CRC_LEN)
 342#define CEPH_EPILOGUE_SECURE_LEN        (CEPH_GCM_BLOCK_LEN + CEPH_GCM_TAG_LEN)
 343
 344#define CEPH_FRAME_MAX_SEGMENT_COUNT    4
 345
 346struct ceph_frame_desc {
 347        int fd_tag;  /* FRAME_TAG_* */
 348        int fd_seg_cnt;
 349        int fd_lens[CEPH_FRAME_MAX_SEGMENT_COUNT];  /* logical */
 350        int fd_aligns[CEPH_FRAME_MAX_SEGMENT_COUNT];
 351};
 352
 353struct ceph_gcm_nonce {
 354        __le32 fixed;
 355        __le64 counter __packed;
 356};
 357
 358struct ceph_connection_v2_info {
 359        struct iov_iter in_iter;
 360        struct kvec in_kvecs[5];  /* recvmsg */
 361        struct bio_vec in_bvec;  /* recvmsg (in_cursor) */
 362        int in_kvec_cnt;
 363        int in_state;  /* IN_S_* */
 364
 365        struct iov_iter out_iter;
 366        struct kvec out_kvecs[8];  /* sendmsg */
 367        struct bio_vec out_bvec;  /* sendpage (out_cursor, out_zero),
 368                                     sendmsg (out_enc_pages) */
 369        int out_kvec_cnt;
 370        int out_state;  /* OUT_S_* */
 371
 372        int out_zero;  /* # of zero bytes to send */
 373        bool out_iter_sendpage;  /* use sendpage if possible */
 374
 375        struct ceph_frame_desc in_desc;
 376        struct ceph_msg_data_cursor in_cursor;
 377        struct ceph_msg_data_cursor out_cursor;
 378
 379        struct crypto_shash *hmac_tfm;  /* post-auth signature */
 380        struct crypto_aead *gcm_tfm;  /* on-wire encryption */
 381        struct aead_request *gcm_req;
 382        struct crypto_wait gcm_wait;
 383        struct ceph_gcm_nonce in_gcm_nonce;
 384        struct ceph_gcm_nonce out_gcm_nonce;
 385
 386        struct page **out_enc_pages;
 387        int out_enc_page_cnt;
 388        int out_enc_resid;
 389        int out_enc_i;
 390
 391        int con_mode;  /* CEPH_CON_MODE_* */
 392
 393        void *conn_bufs[16];
 394        int conn_buf_cnt;
 395
 396        struct kvec in_sign_kvecs[8];
 397        struct kvec out_sign_kvecs[8];
 398        int in_sign_kvec_cnt;
 399        int out_sign_kvec_cnt;
 400
 401        u64 client_cookie;
 402        u64 server_cookie;
 403        u64 global_seq;
 404        u64 connect_seq;
 405        u64 peer_global_seq;
 406
 407        u8 in_buf[CEPH_PREAMBLE_SECURE_LEN];
 408        u8 out_buf[CEPH_PREAMBLE_SECURE_LEN];
 409        struct {
 410                u8 late_status;  /* FRAME_LATE_STATUS_* */
 411                union {
 412                        struct {
 413                                u32 front_crc;
 414                                u32 middle_crc;
 415                                u32 data_crc;
 416                        } __packed;
 417                        u8 pad[CEPH_GCM_BLOCK_LEN - 1];
 418                };
 419        } out_epil;
 420};
 421
 422/*
 423 * A single connection with another host.
 424 *
 425 * We maintain a queue of outgoing messages, and some session state to
 426 * ensure that we can preserve the lossless, ordered delivery of
 427 * messages in the case of a TCP disconnect.
 428 */
 429struct ceph_connection {
 430        void *private;
 431
 432        const struct ceph_connection_operations *ops;
 433
 434        struct ceph_messenger *msgr;
 435
 436        int state;  /* CEPH_CON_S_* */
 437        atomic_t sock_state;
 438        struct socket *sock;
 439
 440        unsigned long flags;  /* CEPH_CON_F_* */
 441        const char *error_msg;  /* error message, if any */
 442
 443        struct ceph_entity_name peer_name; /* peer name */
 444        struct ceph_entity_addr peer_addr; /* peer address */
 445        u64 peer_features;
 446
 447        struct mutex mutex;
 448
 449        /* out queue */
 450        struct list_head out_queue;
 451        struct list_head out_sent;   /* sending or sent but unacked */
 452        u64 out_seq;                 /* last message queued for send */
 453
 454        u64 in_seq, in_seq_acked;  /* last message received, acked */
 455
 456        struct ceph_msg *in_msg;
 457        struct ceph_msg *out_msg;        /* sending message (== tail of
 458                                            out_sent) */
 459
 460        u32 in_front_crc, in_middle_crc, in_data_crc;  /* calculated crc */
 461
 462        struct timespec64 last_keepalive_ack; /* keepalive2 ack stamp */
 463
 464        struct delayed_work work;           /* send|recv work */
 465        unsigned long       delay;          /* current delay interval */
 466
 467        union {
 468                struct ceph_connection_v1_info v1;
 469                struct ceph_connection_v2_info v2;
 470        };
 471};
 472
 473extern struct page *ceph_zero_page;
 474
 475void ceph_con_flag_clear(struct ceph_connection *con, unsigned long con_flag);
 476void ceph_con_flag_set(struct ceph_connection *con, unsigned long con_flag);
 477bool ceph_con_flag_test(struct ceph_connection *con, unsigned long con_flag);
 478bool ceph_con_flag_test_and_clear(struct ceph_connection *con,
 479                                  unsigned long con_flag);
 480bool ceph_con_flag_test_and_set(struct ceph_connection *con,
 481                                unsigned long con_flag);
 482
 483void ceph_encode_my_addr(struct ceph_messenger *msgr);
 484
 485int ceph_tcp_connect(struct ceph_connection *con);
 486int ceph_con_close_socket(struct ceph_connection *con);
 487void ceph_con_reset_session(struct ceph_connection *con);
 488
 489u32 ceph_get_global_seq(struct ceph_messenger *msgr, u32 gt);
 490void ceph_con_discard_sent(struct ceph_connection *con, u64 ack_seq);
 491void ceph_con_discard_requeued(struct ceph_connection *con, u64 reconnect_seq);
 492
 493void ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor,
 494                               struct ceph_msg *msg, size_t length);
 495struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
 496                                size_t *page_offset, size_t *length,
 497                                bool *last_piece);
 498void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor, size_t bytes);
 499
 500u32 ceph_crc32c_page(u32 crc, struct page *page, unsigned int page_offset,
 501                     unsigned int length);
 502
 503bool ceph_addr_is_blank(const struct ceph_entity_addr *addr);
 504int ceph_addr_port(const struct ceph_entity_addr *addr);
 505void ceph_addr_set_port(struct ceph_entity_addr *addr, int p);
 506
 507void ceph_con_process_message(struct ceph_connection *con);
 508int ceph_con_in_msg_alloc(struct ceph_connection *con,
 509                          struct ceph_msg_header *hdr, int *skip);
 510void ceph_con_get_out_msg(struct ceph_connection *con);
 511
 512/* messenger_v1.c */
 513int ceph_con_v1_try_read(struct ceph_connection *con);
 514int ceph_con_v1_try_write(struct ceph_connection *con);
 515void ceph_con_v1_revoke(struct ceph_connection *con);
 516void ceph_con_v1_revoke_incoming(struct ceph_connection *con);
 517bool ceph_con_v1_opened(struct ceph_connection *con);
 518void ceph_con_v1_reset_session(struct ceph_connection *con);
 519void ceph_con_v1_reset_protocol(struct ceph_connection *con);
 520
 521/* messenger_v2.c */
 522int ceph_con_v2_try_read(struct ceph_connection *con);
 523int ceph_con_v2_try_write(struct ceph_connection *con);
 524void ceph_con_v2_revoke(struct ceph_connection *con);
 525void ceph_con_v2_revoke_incoming(struct ceph_connection *con);
 526bool ceph_con_v2_opened(struct ceph_connection *con);
 527void ceph_con_v2_reset_session(struct ceph_connection *con);
 528void ceph_con_v2_reset_protocol(struct ceph_connection *con);
 529
 530
 531extern const char *ceph_pr_addr(const struct ceph_entity_addr *addr);
 532
 533extern int ceph_parse_ips(const char *c, const char *end,
 534                          struct ceph_entity_addr *addr,
 535                          int max_count, int *count);
 536
 537extern int ceph_msgr_init(void);
 538extern void ceph_msgr_exit(void);
 539extern void ceph_msgr_flush(void);
 540
 541extern void ceph_messenger_init(struct ceph_messenger *msgr,
 542                                struct ceph_entity_addr *myaddr);
 543extern void ceph_messenger_fini(struct ceph_messenger *msgr);
 544extern void ceph_messenger_reset_nonce(struct ceph_messenger *msgr);
 545
 546extern void ceph_con_init(struct ceph_connection *con, void *private,
 547                        const struct ceph_connection_operations *ops,
 548                        struct ceph_messenger *msgr);
 549extern void ceph_con_open(struct ceph_connection *con,
 550                          __u8 entity_type, __u64 entity_num,
 551                          struct ceph_entity_addr *addr);
 552extern bool ceph_con_opened(struct ceph_connection *con);
 553extern void ceph_con_close(struct ceph_connection *con);
 554extern void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg);
 555
 556extern void ceph_msg_revoke(struct ceph_msg *msg);
 557extern void ceph_msg_revoke_incoming(struct ceph_msg *msg);
 558
 559extern void ceph_con_keepalive(struct ceph_connection *con);
 560extern bool ceph_con_keepalive_expired(struct ceph_connection *con,
 561                                       unsigned long interval);
 562
 563void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
 564                             size_t length, size_t alignment, bool own_pages);
 565extern void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
 566                                struct ceph_pagelist *pagelist);
 567#ifdef CONFIG_BLOCK
 568void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
 569                           u32 length);
 570#endif /* CONFIG_BLOCK */
 571void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
 572                             struct ceph_bvec_iter *bvec_pos);
 573
 574struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
 575                               gfp_t flags, bool can_fail);
 576extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
 577                                     bool can_fail);
 578
 579extern struct ceph_msg *ceph_msg_get(struct ceph_msg *msg);
 580extern void ceph_msg_put(struct ceph_msg *msg);
 581
 582extern void ceph_msg_dump(struct ceph_msg *msg);
 583
 584#endif
 585