include/linux/ceph/messenger.h

   1 #ifndef __FS_CEPH_MESSENGER_H
   2 #define __FS_CEPH_MESSENGER_H
   3
   4 #include <linux/kref.h>
   5 #include <linux/mutex.h>
   6 #include <linux/net.h>
   7 #include <linux/radix-tree.h>
   8 #include <linux/uio.h>
   9 #include <linux/version.h>
  10 #include <linux/workqueue.h>
  11
  12 #include "types.h"
  13 #include "buffer.h"
  14
  15 struct ceph_msg;
  16 struct ceph_connection;
  17
  18 extern struct workqueue_struct *ceph_msgr_wq;       /* receive work queue */
  19
  20 /*
  21  * Ceph defines these callbacks for handling connection events.
  22  */
  23 struct ceph_connection_operations {
  24         struct ceph_connection *(*get)(struct ceph_connection *);
  25         void (*put)(struct ceph_connection *);
  26
  27         /* handle an incoming message. */
  28         void (*dispatch) (struct ceph_connection *con, struct ceph_msg *m);
  29
  30         /* authorize an outgoing connection */
  31         int (*get_authorizer) (struct ceph_connection *con,
  32                                void **buf, int *len, int *proto,
  33                                void **reply_buf, int *reply_len, int force_new);
  34         int (*verify_authorizer_reply) (struct ceph_connection *con, int len);
  35         int (*invalidate_authorizer)(struct ceph_connection *con);
  36
  37         /* protocol version mismatch */
  38         void (*bad_proto) (struct ceph_connection *con);
  39
  40         /* there was some error on the socket (disconnect, whatever) */
  41         void (*fault) (struct ceph_connection *con);
  42
  43         /* a remote host as terminated a message exchange session, and messages
  44          * we sent (or they tried to send us) may be lost. */
  45         void (*peer_reset) (struct ceph_connection *con);
  46
  47         struct ceph_msg * (*alloc_msg) (struct ceph_connection *con,
  48                                         struct ceph_msg_header *hdr,
  49                                         int *skip);
  50 };
  51
  52 /* use format string %s%d */
  53 #define ENTITY_NAME(n) ceph_entity_type_name((n).type), le64_to_cpu((n).num)
  54
  55 struct ceph_messenger {
  56         struct ceph_entity_inst inst;    /* my name+address */
  57         struct ceph_entity_addr my_enc_addr;
  58         struct page *zero_page;          /* used in certain error cases */
  59
  60         bool nocrc;
  61
  62         /*
  63          * the global_seq counts connections i (attempt to) initiate
  64          * in order to disambiguate certain connect race conditions.
  65          */
  66         u32 global_seq;
  67         spinlock_t global_seq_lock;
  68
  69         u32 supported_features;
  70         u32 required_features;
  71 };
  72
  73 /*
  74  * a single message.  it contains a header (src, dest, message type, etc.),
  75  * footer (crc values, mainly), a "front" message body, and possibly a
  76  * data payload (stored in some number of pages).
  77  */
  78 struct ceph_msg {
  79         struct ceph_msg_header hdr;     /* header */
  80         struct ceph_msg_footer footer;  /* footer */
  81         struct kvec front;              /* unaligned blobs of message */
  82         struct ceph_buffer *middle;
  83         struct page **pages;            /* data payload.  NOT OWNER. */
  84         unsigned nr_pages;              /* size of page array */
  85         struct ceph_pagelist *pagelist; /* instead of pages */
  86         struct list_head list_head;
  87         struct kref kref;
  88         struct bio  *bio;               /* instead of pages/pagelist */
  89         struct bio  *bio_iter;          /* bio iterator */
  90         int bio_seg;                    /* current bio segment */
  91         struct ceph_pagelist *trail;    /* the trailing part of the data */
  92         bool front_is_vmalloc;
  93         bool more_to_follow;
  94         bool needs_out_seq;
  95         int front_max;
  96
  97         struct ceph_msgpool *pool;
  98 };
  99
 100 struct ceph_msg_pos {
 101         int page, page_pos;  /* which page; offset in page */
 102         int data_pos;        /* offset in data payload */
 103         int did_page_crc;    /* true if we've calculated crc for current page */
 104 };
 105
 106 /* ceph connection fault delay defaults, for exponential backoff */
 107 #define BASE_DELAY_INTERVAL     (HZ/2)
 108 #define MAX_DELAY_INTERVAL      (5 * 60 * HZ)
 109
 110 /*
 111  * ceph_connection state bit flags
 112  *
 113  * QUEUED and BUSY are used together to ensure that only a single
 114  * thread is currently opening, reading or writing data to the socket.
 115  */
 116 #define LOSSYTX         0  /* we can close channel or drop messages on errors */
 117 #define CONNECTING      1
 118 #define NEGOTIATING     2
 119 #define KEEPALIVE_PENDING      3
 120 #define WRITE_PENDING   4  /* we have data ready to send */
 121 #define QUEUED          5  /* there is work queued on this connection */
 122 #define BUSY            6  /* work is being done */
 123 #define STANDBY         8  /* no outgoing messages, socket closed.  we keep
 124                             * the ceph_connection around to maintain shared
 125                             * state with the peer. */
 126 #define CLOSED          10 /* we've closed the connection */
 127 #define SOCK_CLOSED     11 /* socket state changed to closed */
 128 #define OPENING         13 /* open connection w/ (possibly new) peer */
 129 #define DEAD            14 /* dead, about to kfree */
 130
 131 /*
 132  * A single connection with another host.
 133  *
 134  * We maintain a queue of outgoing messages, and some session state to
 135  * ensure that we can preserve the lossless, ordered delivery of
 136  * messages in the case of a TCP disconnect.
 137  */
 138 struct ceph_connection {
 139         void *private;
 140         atomic_t nref;
 141
 142         const struct ceph_connection_operations *ops;
 143
 144         struct ceph_messenger *msgr;
 145         struct socket *sock;
 146         unsigned long state;    /* connection state (see flags above) */
 147         const char *error_msg;  /* error message, if any */
 148
 149         struct ceph_entity_addr peer_addr; /* peer address */
 150         struct ceph_entity_name peer_name; /* peer name */
 151         struct ceph_entity_addr peer_addr_for_me;
 152         unsigned peer_features;
 153         u32 connect_seq;      /* identify the most recent connection
 154                                  attempt for this connection, client */
 155         u32 peer_global_seq;  /* peer's global seq for this connection */
 156
 157         int auth_retry;       /* true if we need a newer authorizer */
 158         void *auth_reply_buf;   /* where to put the authorizer reply */
 159         int auth_reply_buf_len;
 160
 161         struct mutex mutex;
 162
 163         /* out queue */
 164         struct list_head out_queue;
 165         struct list_head out_sent;   /* sending or sent but unacked */
 166         u64 out_seq;                 /* last message queued for send */
 167         bool out_keepalive_pending;
 168
 169         u64 in_seq, in_seq_acked;  /* last message received, acked */
 170
 171         /* connection negotiation temps */
 172         char in_banner[CEPH_BANNER_MAX_LEN];
 173         union {
 174                 struct {  /* outgoing connection */
 175                         struct ceph_msg_connect out_connect;
 176                         struct ceph_msg_connect_reply in_reply;
 177                 };
 178                 struct {  /* incoming */
 179                         struct ceph_msg_connect in_connect;
 180                         struct ceph_msg_connect_reply out_reply;
 181                 };
 182         };
 183         struct ceph_entity_addr actual_peer_addr;
 184
 185         /* message out temps */
 186         struct ceph_msg *out_msg;        /* sending message (== tail of
 187                                             out_sent) */
 188         bool out_msg_done;
 189         struct ceph_msg_pos out_msg_pos;
 190
 191         struct kvec out_kvec[8],         /* sending header/footer data */
 192                 *out_kvec_cur;
 193         int out_kvec_left;   /* kvec's left in out_kvec */
 194         int out_skip;        /* skip this many bytes */
 195         int out_kvec_bytes;  /* total bytes left */
 196         bool out_kvec_is_msg; /* kvec refers to out_msg */
 197         int out_more;        /* there is more data after the kvecs */
 198         __le64 out_temp_ack; /* for writing an ack */
 199
 200         /* message in temps */
 201         struct ceph_msg_header in_hdr;
 202         struct ceph_msg *in_msg;
 203         struct ceph_msg_pos in_msg_pos;
 204         u32 in_front_crc, in_middle_crc, in_data_crc;  /* calculated crc */
 205
 206         char in_tag;         /* protocol control byte */
 207         int in_base_pos;     /* bytes read */
 208         __le64 in_temp_ack;  /* for reading an ack */
 209
 210         struct delayed_work work;           /* send|recv work */
 211         unsigned long       delay;          /* current delay interval */
 212 };
 213
 214
 215 extern const char *ceph_pr_addr(const struct sockaddr_storage *ss);
 216 extern int ceph_parse_ips(const char *c, const char *end,
 217                           struct ceph_entity_addr *addr,
 218                           int max_count, int *count);
 219
 220
 221 extern int ceph_msgr_init(void);
 222 extern void ceph_msgr_exit(void);
 223 extern void ceph_msgr_flush(void);
 224
 225 extern struct ceph_messenger *ceph_messenger_create(
 226         struct ceph_entity_addr *myaddr,
 227         u32 features, u32 required);
 228 extern void ceph_messenger_destroy(struct ceph_messenger *);
 229
 230 extern void ceph_con_init(struct ceph_messenger *msgr,
 231                           struct ceph_connection *con);
 232 extern void ceph_con_open(struct ceph_connection *con,
 233                           struct ceph_entity_addr *addr);
 234 extern bool ceph_con_opened(struct ceph_connection *con);
 235 extern void ceph_con_close(struct ceph_connection *con);
 236 extern void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg);
 237 extern void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg);
 238 extern void ceph_con_revoke_message(struct ceph_connection *con,
 239                                   struct ceph_msg *msg);
 240 extern void ceph_con_keepalive(struct ceph_connection *con);
 241 extern struct ceph_connection *ceph_con_get(struct ceph_connection *con);
 242 extern void ceph_con_put(struct ceph_connection *con);
 243
 244 extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags);
 245 extern void ceph_msg_kfree(struct ceph_msg *m);
 246
 247
 248 static inline struct ceph_msg *ceph_msg_get(struct ceph_msg *msg)
 249 {
 250         kref_get(&msg->kref);
 251         return msg;
 252 }
 253 extern void ceph_msg_last_put(struct kref *kref);
 254 static inline void ceph_msg_put(struct ceph_msg *msg)
 255 {
 256         kref_put(&msg->kref, ceph_msg_last_put);
 257 }
 258
 259 extern void ceph_msg_dump(struct ceph_msg *msg);
 260
 261 #endif