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