root/include/linux/ceph/messenger.h

INCLUDED FROM

DEFINITIONS

1. ceph_msg_data_type_valid

#ifndef __FS_CEPH_MESSENGER_H
#define __FS_CEPH_MESSENGER_H

#include <linux/blk_types.h>
#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/net.h>
#include <linux/radix-tree.h>
#include <linux/uio.h>
#include <linux/workqueue.h>

#include <linux/ceph/types.h>
#include <linux/ceph/buffer.h>

struct ceph_msg;
struct ceph_connection;

/*
 * Ceph defines these callbacks for handling connection events.
 */
struct ceph_connection_operations {
        struct ceph_connection *(*get)(struct ceph_connection *);
        void (*put)(struct ceph_connection *);

        /* handle an incoming message. */
        void (*dispatch) (struct ceph_connection *con, struct ceph_msg *m);

        /* authorize an outgoing connection */
        struct ceph_auth_handshake *(*get_authorizer) (
                                struct ceph_connection *con,
                               int *proto, int force_new);
        int (*verify_authorizer_reply) (struct ceph_connection *con, int len);
        int (*invalidate_authorizer)(struct ceph_connection *con);

        /* there was some error on the socket (disconnect, whatever) */
        void (*fault) (struct ceph_connection *con);

        /* a remote host as terminated a message exchange session, and messages
         * we sent (or they tried to send us) may be lost. */
        void (*peer_reset) (struct ceph_connection *con);

        struct ceph_msg * (*alloc_msg) (struct ceph_connection *con,
                                        struct ceph_msg_header *hdr,
                                        int *skip);
};

/* use format string %s%d */
#define ENTITY_NAME(n) ceph_entity_type_name((n).type), le64_to_cpu((n).num)

struct ceph_messenger {
        struct ceph_entity_inst inst;    /* my name+address */
        struct ceph_entity_addr my_enc_addr;

        atomic_t stopping;
        bool nocrc;

        /*
         * the global_seq counts connections i (attempt to) initiate
         * in order to disambiguate certain connect race conditions.
         */
        u32 global_seq;
        spinlock_t global_seq_lock;

        u64 supported_features;
        u64 required_features;
};

enum ceph_msg_data_type {
        CEPH_MSG_DATA_NONE,     /* message contains no data payload */
        CEPH_MSG_DATA_PAGES,    /* data source/destination is a page array */
        CEPH_MSG_DATA_PAGELIST, /* data source/destination is a pagelist */
#ifdef CONFIG_BLOCK
        CEPH_MSG_DATA_BIO,      /* data source/destination is a bio list */
#endif /* CONFIG_BLOCK */
};

static __inline__ bool ceph_msg_data_type_valid(enum ceph_msg_data_type type)
{
        switch (type) {
        case CEPH_MSG_DATA_NONE:
        case CEPH_MSG_DATA_PAGES:
        case CEPH_MSG_DATA_PAGELIST:
#ifdef CONFIG_BLOCK
        case CEPH_MSG_DATA_BIO:
#endif /* CONFIG_BLOCK */
                return true;
        default:
                return false;
        }
}

struct ceph_msg_data {
        struct list_head                links;  /* ceph_msg->data */
        enum ceph_msg_data_type         type;
        union {
#ifdef CONFIG_BLOCK
                struct {
                        struct bio      *bio;
                        size_t          bio_length;
                };
#endif /* CONFIG_BLOCK */
                struct {
                        struct page     **pages;        /* NOT OWNER. */
                        size_t          length;         /* total # bytes */
                        unsigned int    alignment;      /* first page */
                };
                struct ceph_pagelist    *pagelist;
        };
};

struct ceph_msg_data_cursor {
        size_t                  total_resid;    /* across all data items */
        struct list_head        *data_head;     /* = &ceph_msg->data */

        struct ceph_msg_data    *data;          /* current data item */
        size_t                  resid;          /* bytes not yet consumed */
        bool                    last_piece;     /* current is last piece */
        bool                    need_crc;       /* crc update needed */
        union {
#ifdef CONFIG_BLOCK
                struct {                                /* bio */
                        struct bio      *bio;           /* bio from list */
                        struct bvec_iter bvec_iter;
                };
#endif /* CONFIG_BLOCK */
                struct {                                /* pages */
                        unsigned int    page_offset;    /* offset in page */
                        unsigned short  page_index;     /* index in array */
                        unsigned short  page_count;     /* pages in array */
                };
                struct {                                /* pagelist */
                        struct page     *page;          /* page from list */
                        size_t          offset;         /* bytes from list */
                };
        };
};

/*
 * a single message.  it contains a header (src, dest, message type, etc.),
 * footer (crc values, mainly), a "front" message body, and possibly a
 * data payload (stored in some number of pages).
 */
struct ceph_msg {
        struct ceph_msg_header hdr;     /* header */
        struct ceph_msg_footer footer;  /* footer */
        struct kvec front;              /* unaligned blobs of message */
        struct ceph_buffer *middle;

        size_t                          data_length;
        struct list_head                data;
        struct ceph_msg_data_cursor     cursor;

        struct ceph_connection *con;
        struct list_head list_head;     /* links for connection lists */

        struct kref kref;
        bool more_to_follow;
        bool needs_out_seq;
        int front_alloc_len;
        unsigned long ack_stamp;        /* tx: when we were acked */

        struct ceph_msgpool *pool;
};

/* ceph connection fault delay defaults, for exponential backoff */
#define BASE_DELAY_INTERVAL     (HZ/2)
#define MAX_DELAY_INTERVAL      (5 * 60 * HZ)

/*
 * A single connection with another host.
 *
 * We maintain a queue of outgoing messages, and some session state to
 * ensure that we can preserve the lossless, ordered delivery of
 * messages in the case of a TCP disconnect.
 */
struct ceph_connection {
        void *private;

        const struct ceph_connection_operations *ops;

        struct ceph_messenger *msgr;

        atomic_t sock_state;
        struct socket *sock;
        struct ceph_entity_addr peer_addr; /* peer address */
        struct ceph_entity_addr peer_addr_for_me;

        unsigned long flags;
        unsigned long state;
        const char *error_msg;  /* error message, if any */

        struct ceph_entity_name peer_name; /* peer name */

        u64 peer_features;
        u32 connect_seq;      /* identify the most recent connection
                                 attempt for this connection, client */
        u32 peer_global_seq;  /* peer's global seq for this connection */

        int auth_retry;       /* true if we need a newer authorizer */
        void *auth_reply_buf;   /* where to put the authorizer reply */
        int auth_reply_buf_len;

        struct mutex mutex;

        /* out queue */
        struct list_head out_queue;
        struct list_head out_sent;   /* sending or sent but unacked */
        u64 out_seq;                 /* last message queued for send */

        u64 in_seq, in_seq_acked;  /* last message received, acked */

        /* connection negotiation temps */
        char in_banner[CEPH_BANNER_MAX_LEN];
        struct ceph_msg_connect out_connect;
        struct ceph_msg_connect_reply in_reply;
        struct ceph_entity_addr actual_peer_addr;

        /* message out temps */
        struct ceph_msg *out_msg;        /* sending message (== tail of
                                            out_sent) */
        bool out_msg_done;

        struct kvec out_kvec[8],         /* sending header/footer data */
                *out_kvec_cur;
        int out_kvec_left;   /* kvec's left in out_kvec */
        int out_skip;        /* skip this many bytes */
        int out_kvec_bytes;  /* total bytes left */
        bool out_kvec_is_msg; /* kvec refers to out_msg */
        int out_more;        /* there is more data after the kvecs */
        __le64 out_temp_ack; /* for writing an ack */

        /* message in temps */
        struct ceph_msg_header in_hdr;
        struct ceph_msg *in_msg;
        u32 in_front_crc, in_middle_crc, in_data_crc;  /* calculated crc */

        char in_tag;         /* protocol control byte */
        int in_base_pos;     /* bytes read */
        __le64 in_temp_ack;  /* for reading an ack */

        struct delayed_work work;           /* send|recv work */
        unsigned long       delay;          /* current delay interval */
};


extern const char *ceph_pr_addr(const struct sockaddr_storage *ss);
extern int ceph_parse_ips(const char *c, const char *end,
                          struct ceph_entity_addr *addr,
                          int max_count, int *count);


extern int ceph_msgr_init(void);
extern void ceph_msgr_exit(void);
extern void ceph_msgr_flush(void);

extern void ceph_messenger_init(struct ceph_messenger *msgr,
                        struct ceph_entity_addr *myaddr,
                        u64 supported_features,
                        u64 required_features,
                        bool nocrc);

extern void ceph_con_init(struct ceph_connection *con, void *private,
                        const struct ceph_connection_operations *ops,
                        struct ceph_messenger *msgr);
extern void ceph_con_open(struct ceph_connection *con,
                          __u8 entity_type, __u64 entity_num,
                          struct ceph_entity_addr *addr);
extern bool ceph_con_opened(struct ceph_connection *con);
extern void ceph_con_close(struct ceph_connection *con);
extern void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg);

extern void ceph_msg_revoke(struct ceph_msg *msg);
extern void ceph_msg_revoke_incoming(struct ceph_msg *msg);

extern void ceph_con_keepalive(struct ceph_connection *con);

extern void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
                                size_t length, size_t alignment);
extern void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
                                struct ceph_pagelist *pagelist);
#ifdef CONFIG_BLOCK
extern void ceph_msg_data_add_bio(struct ceph_msg *msg, struct bio *bio,
                                size_t length);
#endif /* CONFIG_BLOCK */

extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
                                     bool can_fail);

extern struct ceph_msg *ceph_msg_get(struct ceph_msg *msg);
extern void ceph_msg_put(struct ceph_msg *msg);

extern void ceph_msg_dump(struct ceph_msg *msg);

#endif