LXR linux/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/ktime.h>
  16#include <linux/sunrpc/sched.h>
  17#include <linux/sunrpc/xdr.h>
  18#include <linux/sunrpc/msg_prot.h>
  19
  20#ifdef __KERNEL__
  21
  22#define RPC_MIN_SLOT_TABLE      (2U)
  23#define RPC_DEF_SLOT_TABLE      (16U)
  24#define RPC_MAX_SLOT_TABLE_LIMIT        (65536U)
  25#define RPC_MAX_SLOT_TABLE      RPC_MAX_SLOT_TABLE_LIMIT
  26
  27/*
  28 * This describes a timeout strategy
  29 */
  30struct 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
  38enum 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
  48struct rpc_task;
  49struct rpc_xprt;
  50struct seq_file;
  51
  52/*
  53 * This describes a complete RPC request
  54 */
  55struct 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        struct rpc_cred *       rq_cred;        /* Bound cred */
  68        __be32                  rq_xid;         /* request XID */
  69        int                     rq_cong;        /* has incremented xprt->cong */
  70        u32                     rq_seqno;       /* gss seq no. used on req. */
  71        int                     rq_enc_pages_num;
  72        struct page             **rq_enc_pages; /* scratch pages for use by
  73                                                   gss privacy code */
  74        void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  75        struct list_head        rq_list;
  76
  77        __u32 *                 rq_buffer;      /* XDR encode buffer */
  78        size_t                  rq_callsize,
  79                                rq_rcvsize;
  80        size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  81        size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  82                                                        /* received */
  83
  84        struct xdr_buf          rq_private_buf;         /* The receive buffer
  85                                                         * used in the softirq.
  86                                                         */
  87        unsigned long           rq_majortimeo;  /* major timeout alarm */
  88        unsigned long           rq_timeout;     /* Current timeout value */
  89        ktime_t                 rq_rtt;         /* round-trip time */
  90        unsigned int            rq_retries;     /* # of retries */
  91        unsigned int            rq_connect_cookie;
  92                                                /* A cookie used to track the
  93                                                   state of the transport
  94                                                   connection */
  95        
  96        /*
  97         * Partial send handling
  98         */
  99        u32                     rq_bytes_sent;  /* Bytes we have sent */
 100
 101        ktime_t                 rq_xtime;       /* transmit time stamp */
 102        int                     rq_ntrans;
 103
 104#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 105        struct list_head        rq_bc_list;     /* Callback service list */
 106        unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 107        struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 108#endif /* CONFIG_SUNRPC_BACKCHANEL */
 109};
 110#define rq_svec                 rq_snd_buf.head
 111#define rq_slen                 rq_snd_buf.len
 112
 113struct rpc_xprt_ops {
 114        void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 115        int             (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 116        void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 117        void            (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
 118        void            (*rpcbind)(struct rpc_task *task);
 119        void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 120        void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 121        void *          (*buf_alloc)(struct rpc_task *task, size_t size);
 122        void            (*buf_free)(void *buffer);
 123        int             (*send_request)(struct rpc_task *task);
 124        void            (*set_retrans_timeout)(struct rpc_task *task);
 125        void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 126        void            (*release_request)(struct rpc_task *task);
 127        void            (*close)(struct rpc_xprt *xprt);
 128        void            (*destroy)(struct rpc_xprt *xprt);
 129        void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 130};
 131
 132/*
 133 * RPC transport identifiers
 134 *
 135 * To preserve compatibility with the historical use of raw IP protocol
 136 * id's for transport selection, UDP and TCP identifiers are specified
 137 * with the previous values. No such restriction exists for new transports,
 138 * except that they may not collide with these values (17 and 6,
 139 * respectively).
 140 */
 141#define XPRT_TRANSPORT_BC       (1 << 31)
 142enum xprt_transports {
 143        XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 144        XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 145        XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 146        XPRT_TRANSPORT_RDMA     = 256,
 147        XPRT_TRANSPORT_LOCAL    = 257,
 148};
 149
 150struct rpc_xprt {
 151        atomic_t                count;          /* Reference count */
 152        struct rpc_xprt_ops *   ops;            /* transport methods */
 153
 154        const struct rpc_timeout *timeout;      /* timeout parms */
 155        struct sockaddr_storage addr;           /* server address */
 156        size_t                  addrlen;        /* size of server address */
 157        int                     prot;           /* IP protocol */
 158
 159        unsigned long           cong;           /* current congestion */
 160        unsigned long           cwnd;           /* congestion window */
 161
 162        size_t                  max_payload;    /* largest RPC payload size,
 163                                                   in bytes */
 164        unsigned int            tsh_size;       /* size of transport specific
 165                                                   header */
 166
 167        struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 168        struct rpc_wait_queue   sending;        /* requests waiting to send */
 169        struct rpc_wait_queue   pending;        /* requests in flight */
 170        struct rpc_wait_queue   backlog;        /* waiting for slot */
 171        struct list_head        free;           /* free slots */
 172        unsigned int            max_reqs;       /* max number of slots */
 173        unsigned int            min_reqs;       /* min number of slots */
 174        atomic_t                num_reqs;       /* total slots */
 175        unsigned long           state;          /* transport state */
 176        unsigned char           resvport   : 1; /* use a reserved port */
 177        unsigned int            swapper;        /* we're swapping over this
 178                                                   transport */
 179        unsigned int            bind_index;     /* bind function index */
 180
 181        /*
 182         * Connection of transports
 183         */
 184        unsigned long           bind_timeout,
 185                                reestablish_timeout;
 186        unsigned int            connect_cookie; /* A cookie that gets bumped
 187                                                   every time the transport
 188                                                   is reconnected */
 189
 190        /*
 191         * Disconnection of idle transports
 192         */
 193        struct work_struct      task_cleanup;
 194        struct timer_list       timer;
 195        unsigned long           last_used,
 196                                idle_timeout;
 197
 198        /*
 199         * Send stuff
 200         */
 201        spinlock_t              transport_lock; /* lock transport info */
 202        spinlock_t              reserve_lock;   /* lock slot table */
 203        u32                     xid;            /* Next XID value to use */
 204        struct rpc_task *       snd_task;       /* Task blocked in send */
 205        struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 206#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 207        struct svc_serv         *bc_serv;       /* The RPC service which will */
 208                                                /* process the callback */
 209        unsigned int            bc_alloc_count; /* Total number of preallocs */
 210        spinlock_t              bc_pa_lock;     /* Protects the preallocated
 211                                                 * items */
 212        struct list_head        bc_pa_list;     /* List of preallocated
 213                                                 * backchannel rpc_rqst's */
 214#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 215        struct list_head        recv;
 216
 217        struct {
 218                unsigned long           bind_count,     /* total number of binds */
 219                                        connect_count,  /* total number of connects */
 220                                        connect_start,  /* connect start timestamp */
 221                                        connect_time,   /* jiffies waiting for connect */
 222                                        sends,          /* how many complete requests */
 223                                        recvs,          /* how many complete requests */
 224                                        bad_xids,       /* lookup_rqst didn't find XID */
 225                                        max_slots;      /* max rpc_slots used */
 226
 227                unsigned long long      req_u,          /* average requests on the wire */
 228                                        bklog_u,        /* backlog queue utilization */
 229                                        sending_u,      /* send q utilization */
 230                                        pending_u;      /* pend q utilization */
 231        } stat;
 232
 233        struct net              *xprt_net;
 234        const char              *servername;
 235        const char              *address_strings[RPC_DISPLAY_MAX];
 236};
 237
 238#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 239/*
 240 * Backchannel flags
 241 */
 242#define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 243                                                /* buffer in use */
 244#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 245
 246#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 247static inline int bc_prealloc(struct rpc_rqst *req)
 248{
 249        return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 250}
 251#else
 252static inline int bc_prealloc(struct rpc_rqst *req)
 253{
 254        return 0;
 255}
 256#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 257
 258#define XPRT_CREATE_INFINITE_SLOTS      (1U)
 259#define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 260
 261struct xprt_create {
 262        int                     ident;          /* XPRT_TRANSPORT identifier */
 263        struct net *            net;
 264        struct sockaddr *       srcaddr;        /* optional local address */
 265        struct sockaddr *       dstaddr;        /* remote peer address */
 266        size_t                  addrlen;
 267        const char              *servername;
 268        struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 269        unsigned int            flags;
 270};
 271
 272struct xprt_class {
 273        struct list_head        list;
 274        int                     ident;          /* XPRT_TRANSPORT identifier */
 275        struct rpc_xprt *       (*setup)(struct xprt_create *);
 276        struct module           *owner;
 277        char                    name[32];
 278};
 279
 280/*
 281 * Generic internal transport functions
 282 */
 283struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 284void                    xprt_connect(struct rpc_task *task);
 285void                    xprt_reserve(struct rpc_task *task);
 286void                    xprt_retry_reserve(struct rpc_task *task);
 287int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 288int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 289void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 290void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 291int                     xprt_prepare_transmit(struct rpc_task *task);
 292void                    xprt_transmit(struct rpc_task *task);
 293void                    xprt_end_transmit(struct rpc_task *task);
 294int                     xprt_adjust_timeout(struct rpc_rqst *req);
 295void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 296void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 297void                    xprt_release(struct rpc_task *task);
 298struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 299void                    xprt_put(struct rpc_xprt *xprt);
 300struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 301                                unsigned int num_prealloc,
 302                                unsigned int max_req);
 303void                    xprt_free(struct rpc_xprt *);
 304
 305static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 306{
 307        return p + xprt->tsh_size;
 308}
 309
 310/*
 311 * Transport switch helper functions
 312 */
 313int                     xprt_register_transport(struct xprt_class *type);
 314int                     xprt_unregister_transport(struct xprt_class *type);
 315int                     xprt_load_transport(const char *);
 316void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 317void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 318void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 319void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 320void                    xprt_write_space(struct rpc_xprt *xprt);
 321void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 322struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 323void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 324void                    xprt_release_rqst_cong(struct rpc_task *task);
 325void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 326void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 327void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 328int                     xs_swapper(struct rpc_xprt *xprt, int enable);
 329
 330/*
 331 * Reserved bit positions in xprt->state
 332 */
 333#define XPRT_LOCKED             (0)
 334#define XPRT_CONNECTED          (1)
 335#define XPRT_CONNECTING         (2)
 336#define XPRT_CLOSE_WAIT         (3)
 337#define XPRT_BOUND              (4)
 338#define XPRT_BINDING            (5)
 339#define XPRT_CLOSING            (6)
 340#define XPRT_CONNECTION_ABORT   (7)
 341#define XPRT_CONNECTION_CLOSE   (8)
 342#define XPRT_CONGESTED          (9)
 343
 344static inline void xprt_set_connected(struct rpc_xprt *xprt)
 345{
 346        set_bit(XPRT_CONNECTED, &xprt->state);
 347}
 348
 349static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 350{
 351        clear_bit(XPRT_CONNECTED, &xprt->state);
 352}
 353
 354static inline int xprt_connected(struct rpc_xprt *xprt)
 355{
 356        return test_bit(XPRT_CONNECTED, &xprt->state);
 357}
 358
 359static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 360{
 361        return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 362}
 363
 364static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 365{
 366        return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 367}
 368
 369static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 370{
 371        smp_mb__before_clear_bit();
 372        clear_bit(XPRT_CONNECTING, &xprt->state);
 373        smp_mb__after_clear_bit();
 374}
 375
 376static inline int xprt_connecting(struct rpc_xprt *xprt)
 377{
 378        return test_bit(XPRT_CONNECTING, &xprt->state);
 379}
 380
 381static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 382{
 383        return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 384}
 385
 386static inline void xprt_set_bound(struct rpc_xprt *xprt)
 387{
 388        test_and_set_bit(XPRT_BOUND, &xprt->state);
 389}
 390
 391static inline int xprt_bound(struct rpc_xprt *xprt)
 392{
 393        return test_bit(XPRT_BOUND, &xprt->state);
 394}
 395
 396static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 397{
 398        clear_bit(XPRT_BOUND, &xprt->state);
 399}
 400
 401static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 402{
 403        smp_mb__before_clear_bit();
 404        clear_bit(XPRT_BINDING, &xprt->state);
 405        smp_mb__after_clear_bit();
 406}
 407
 408static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 409{
 410        return test_and_set_bit(XPRT_BINDING, &xprt->state);
 411}
 412
 413#endif /* __KERNEL__*/
 414
 415#endif /* _LINUX_SUNRPC_XPRT_H */
 416