include/linux/sunrpc/xprt.h

   1 /*
   2  *  linux/include/linux/sunrpc/xprt.h
   3  *
   4  *  Declarations for the RPC transport interface.
   5  *
   6  *  Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #ifndef _LINUX_SUNRPC_XPRT_H
  10 #define _LINUX_SUNRPC_XPRT_H
  11
  12 #include <linux/uio.h>
  13 #include <linux/socket.h>
  14 #include <linux/in.h>
  15 #include <linux/kref.h>
  16 #include <linux/ktime.h>
  17 #include <linux/sunrpc/sched.h>
  18 #include <linux/sunrpc/xdr.h>
  19 #include <linux/sunrpc/msg_prot.h>
  20
  21 #ifdef __KERNEL__
  22
  23 #define RPC_MIN_SLOT_TABLE      (2U)
  24 #define RPC_DEF_SLOT_TABLE      (16U)
  25 #define RPC_MAX_SLOT_TABLE      (128U)
  26
  27 /*
  28  * This describes a timeout strategy
  29  */
  30 struct rpc_timeout {
  31         unsigned long           to_initval,             /* initial timeout */
  32                                 to_maxval,              /* max timeout */
  33                                 to_increment;           /* if !exponential */
  34         unsigned int            to_retries;             /* max # of retries */
  35         unsigned char           to_exponential;
  36 };
  37
  38 enum rpc_display_format_t {
  39         RPC_DISPLAY_ADDR = 0,
  40         RPC_DISPLAY_PORT,
  41         RPC_DISPLAY_PROTO,
  42         RPC_DISPLAY_HEX_ADDR,
  43         RPC_DISPLAY_HEX_PORT,
  44         RPC_DISPLAY_NETID,
  45         RPC_DISPLAY_MAX,
  46 };
  47
  48 struct rpc_task;
  49 struct rpc_xprt;
  50 struct seq_file;
  51
  52 /*
  53  * This describes a complete RPC request
  54  */
  55 struct rpc_rqst {
  56         /*
  57          * This is the user-visible part
  58          */
  59         struct rpc_xprt *       rq_xprt;                /* RPC client */
  60         struct xdr_buf          rq_snd_buf;             /* send buffer */
  61         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  62
  63         /*
  64          * This is the private part
  65          */
  66         struct rpc_task *       rq_task;        /* RPC task data */
  67         __be32                  rq_xid;         /* request XID */
  68         int                     rq_cong;        /* has incremented xprt->cong */
  69         u32                     rq_seqno;       /* gss seq no. used on req. */
  70         int                     rq_enc_pages_num;
  71         struct page             **rq_enc_pages; /* scratch pages for use by
  72                                                    gss privacy code */
  73         void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  74         struct list_head        rq_list;
  75
  76         __u32 *                 rq_buffer;      /* XDR encode buffer */
  77         size_t                  rq_callsize,
  78                                 rq_rcvsize;
  79         size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  80         size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  81                                                         /* received */
  82
  83         struct xdr_buf          rq_private_buf;         /* The receive buffer
  84                                                          * used in the softirq.
  85                                                          */
  86         unsigned long           rq_majortimeo;  /* major timeout alarm */
  87         unsigned long           rq_timeout;     /* Current timeout value */
  88         ktime_t                 rq_rtt;         /* round-trip time */
  89         unsigned int            rq_retries;     /* # of retries */
  90         unsigned int            rq_connect_cookie;
  91                                                 /* A cookie used to track the
  92                                                    state of the transport
  93                                                    connection */
  94
  95         /*
  96          * Partial send handling
  97          */
  98         u32                     rq_bytes_sent;  /* Bytes we have sent */
  99
 100         ktime_t                 rq_xtime;       /* transmit time stamp */
 101         int                     rq_ntrans;
 102
 103 #if defined(CONFIG_NFS_V4_1)
 104         struct list_head        rq_bc_list;     /* Callback service list */
 105         unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 106         struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 107 #endif /* CONFIG_NFS_V4_1 */
 108 };
 109 #define rq_svec                 rq_snd_buf.head
 110 #define rq_slen                 rq_snd_buf.len
 111
 112 struct rpc_xprt_ops {
 113         void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 114         int             (*reserve_xprt)(struct rpc_task *task);
 115         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 116         void            (*rpcbind)(struct rpc_task *task);
 117         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 118         void            (*connect)(struct rpc_task *task);
 119         void *          (*buf_alloc)(struct rpc_task *task, size_t size);
 120         void            (*buf_free)(void *buffer);
 121         int             (*send_request)(struct rpc_task *task);
 122         void            (*set_retrans_timeout)(struct rpc_task *task);
 123         void            (*timer)(struct rpc_task *task);
 124         void            (*release_request)(struct rpc_task *task);
 125         void            (*close)(struct rpc_xprt *xprt);
 126         void            (*destroy)(struct rpc_xprt *xprt);
 127         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 128 };
 129
 130 /*
 131  * RPC transport identifiers
 132  *
 133  * To preserve compatibility with the historical use of raw IP protocol
 134  * id's for transport selection, UDP and TCP identifiers are specified
 135  * with the previous values. No such restriction exists for new transports,
 136  * except that they may not collide with these values (17 and 6,
 137  * respectively).
 138  */
 139 #define XPRT_TRANSPORT_BC       (1 << 31)
 140 enum xprt_transports {
 141         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 142         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 143         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 144         XPRT_TRANSPORT_RDMA     = 256
 145 };
 146
 147 struct rpc_xprt {
 148         struct kref             kref;           /* Reference count */
 149         struct rpc_xprt_ops *   ops;            /* transport methods */
 150
 151         const struct rpc_timeout *timeout;      /* timeout parms */
 152         struct sockaddr_storage addr;           /* server address */
 153         size_t                  addrlen;        /* size of server address */
 154         int                     prot;           /* IP protocol */
 155
 156         unsigned long           cong;           /* current congestion */
 157         unsigned long           cwnd;           /* congestion window */
 158
 159         size_t                  max_payload;    /* largest RPC payload size,
 160                                                    in bytes */
 161         unsigned int            tsh_size;       /* size of transport specific
 162                                                    header */
 163
 164         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 165         struct rpc_wait_queue   sending;        /* requests waiting to send */
 166         struct rpc_wait_queue   resend;         /* requests waiting to resend */
 167         struct rpc_wait_queue   pending;        /* requests in flight */
 168         struct rpc_wait_queue   backlog;        /* waiting for slot */
 169         struct list_head        free;           /* free slots */
 170         struct rpc_rqst *       slot;           /* slot table storage */
 171         unsigned int            max_reqs;       /* total slots */
 172         unsigned long           state;          /* transport state */
 173         unsigned char           shutdown   : 1, /* being shut down */
 174                                 resvport   : 1; /* use a reserved port */
 175         unsigned int            bind_index;     /* bind function index */
 176
 177         /*
 178          * Connection of transports
 179          */
 180         unsigned long           bind_timeout,
 181                                 reestablish_timeout;
 182         unsigned int            connect_cookie; /* A cookie that gets bumped
 183                                                    every time the transport
 184                                                    is reconnected */
 185
 186         /*
 187          * Disconnection of idle transports
 188          */
 189         struct work_struct      task_cleanup;
 190         struct timer_list       timer;
 191         unsigned long           last_used,
 192                                 idle_timeout;
 193
 194         /*
 195          * Send stuff
 196          */
 197         spinlock_t              transport_lock; /* lock transport info */
 198         spinlock_t              reserve_lock;   /* lock slot table */
 199         u32                     xid;            /* Next XID value to use */
 200         struct rpc_task *       snd_task;       /* Task blocked in send */
 201         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 202 #if defined(CONFIG_NFS_V4_1)
 203         struct svc_serv         *bc_serv;       /* The RPC service which will */
 204                                                 /* process the callback */
 205         unsigned int            bc_alloc_count; /* Total number of preallocs */
 206         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 207                                                  * items */
 208         struct list_head        bc_pa_list;     /* List of preallocated
 209                                                  * backchannel rpc_rqst's */
 210 #endif /* CONFIG_NFS_V4_1 */
 211         struct list_head        recv;
 212
 213         struct {
 214                 unsigned long           bind_count,     /* total number of binds */
 215                                         connect_count,  /* total number of connects */
 216                                         connect_start,  /* connect start timestamp */
 217                                         connect_time,   /* jiffies waiting for connect */
 218                                         sends,          /* how many complete requests */
 219                                         recvs,          /* how many complete requests */
 220                                         bad_xids;       /* lookup_rqst didn't find XID */
 221
 222                 unsigned long long      req_u,          /* average requests on the wire */
 223                                         bklog_u;        /* backlog queue utilization */
 224         } stat;
 225
 226         const char              *address_strings[RPC_DISPLAY_MAX];
 227 };
 228
 229 #if defined(CONFIG_NFS_V4_1)
 230 /*
 231  * Backchannel flags
 232  */
 233 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 234                                                 /* buffer in use */
 235 #endif /* CONFIG_NFS_V4_1 */
 236
 237 #if defined(CONFIG_NFS_V4_1)
 238 static inline int bc_prealloc(struct rpc_rqst *req)
 239 {
 240         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 241 }
 242 #else
 243 static inline int bc_prealloc(struct rpc_rqst *req)
 244 {
 245         return 0;
 246 }
 247 #endif /* CONFIG_NFS_V4_1 */
 248
 249 struct xprt_create {
 250         int                     ident;          /* XPRT_TRANSPORT identifier */
 251         struct sockaddr *       srcaddr;        /* optional local address */
 252         struct sockaddr *       dstaddr;        /* remote peer address */
 253         size_t                  addrlen;
 254         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 255 };
 256
 257 struct xprt_class {
 258         struct list_head        list;
 259         int                     ident;          /* XPRT_TRANSPORT identifier */
 260         struct rpc_xprt *       (*setup)(struct xprt_create *);
 261         struct module           *owner;
 262         char                    name[32];
 263 };
 264
 265 /*
 266  * Generic internal transport functions
 267  */
 268 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 269 void                    xprt_connect(struct rpc_task *task);
 270 void                    xprt_reserve(struct rpc_task *task);
 271 int                     xprt_reserve_xprt(struct rpc_task *task);
 272 int                     xprt_reserve_xprt_cong(struct rpc_task *task);
 273 int                     xprt_prepare_transmit(struct rpc_task *task);
 274 void                    xprt_transmit(struct rpc_task *task);
 275 void                    xprt_end_transmit(struct rpc_task *task);
 276 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 277 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 278 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 279 void                    xprt_release(struct rpc_task *task);
 280 struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 281 void                    xprt_put(struct rpc_xprt *xprt);
 282
 283 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 284 {
 285         return p + xprt->tsh_size;
 286 }
 287
 288 /*
 289  * Transport switch helper functions
 290  */
 291 int                     xprt_register_transport(struct xprt_class *type);
 292 int                     xprt_unregister_transport(struct xprt_class *type);
 293 int                     xprt_load_transport(const char *);
 294 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 295 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 296 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 297 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 298 void                    xprt_write_space(struct rpc_xprt *xprt);
 299 void                    xprt_adjust_cwnd(struct rpc_task *task, int result);
 300 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 301 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 302 void                    xprt_release_rqst_cong(struct rpc_task *task);
 303 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 304 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 305 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 306
 307 /*
 308  * Reserved bit positions in xprt->state
 309  */
 310 #define XPRT_LOCKED             (0)
 311 #define XPRT_CONNECTED          (1)
 312 #define XPRT_CONNECTING         (2)
 313 #define XPRT_CLOSE_WAIT         (3)
 314 #define XPRT_BOUND              (4)
 315 #define XPRT_BINDING            (5)
 316 #define XPRT_CLOSING            (6)
 317 #define XPRT_CONNECTION_ABORT   (7)
 318 #define XPRT_CONNECTION_CLOSE   (8)
 319
 320 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 321 {
 322         set_bit(XPRT_CONNECTED, &xprt->state);
 323 }
 324
 325 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 326 {
 327         clear_bit(XPRT_CONNECTED, &xprt->state);
 328 }
 329
 330 static inline int xprt_connected(struct rpc_xprt *xprt)
 331 {
 332         return test_bit(XPRT_CONNECTED, &xprt->state);
 333 }
 334
 335 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 336 {
 337         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 338 }
 339
 340 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 341 {
 342         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 343 }
 344
 345 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 346 {
 347         smp_mb__before_clear_bit();
 348         clear_bit(XPRT_CONNECTING, &xprt->state);
 349         smp_mb__after_clear_bit();
 350 }
 351
 352 static inline int xprt_connecting(struct rpc_xprt *xprt)
 353 {
 354         return test_bit(XPRT_CONNECTING, &xprt->state);
 355 }
 356
 357 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 358 {
 359         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 360 }
 361
 362 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 363 {
 364         test_and_set_bit(XPRT_BOUND, &xprt->state);
 365 }
 366
 367 static inline int xprt_bound(struct rpc_xprt *xprt)
 368 {
 369         return test_bit(XPRT_BOUND, &xprt->state);
 370 }
 371
 372 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 373 {
 374         clear_bit(XPRT_BOUND, &xprt->state);
 375 }
 376
 377 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 378 {
 379         smp_mb__before_clear_bit();
 380         clear_bit(XPRT_BINDING, &xprt->state);
 381         smp_mb__after_clear_bit();
 382 }
 383
 384 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 385 {
 386         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 387 }
 388
 389 #endif /* __KERNEL__*/
 390
 391 #endif /* _LINUX_SUNRPC_XPRT_H */