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/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 */
  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_NFS_V4_1)
 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_NFS_V4_1 */
 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_task *task);
 116        void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 117        void            (*rpcbind)(struct rpc_task *task);
 118        void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 119        void            (*connect)(struct rpc_task *task);
 120        void *          (*buf_alloc)(struct rpc_task *task, size_t size);
 121        void            (*buf_free)(void *buffer);
 122        int             (*send_request)(struct rpc_task *task);
 123        void            (*set_retrans_timeout)(struct rpc_task *task);
 124        void            (*timer)(struct rpc_task *task);
 125        void            (*release_request)(struct rpc_task *task);
 126        void            (*close)(struct rpc_xprt *xprt);
 127        void            (*destroy)(struct rpc_xprt *xprt);
 128        void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 129};
 130
 131/*
 132 * RPC transport identifiers
 133 *
 134 * To preserve compatibility with the historical use of raw IP protocol
 135 * id's for transport selection, UDP and TCP identifiers are specified
 136 * with the previous values. No such restriction exists for new transports,
 137 * except that they may not collide with these values (17 and 6,
 138 * respectively).
 139 */
 140#define XPRT_TRANSPORT_BC       (1 << 31)
 141enum xprt_transports {
 142        XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 143        XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 144        XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 145        XPRT_TRANSPORT_RDMA     = 256
 146};
 147
 148struct rpc_xprt {
 149        struct kref             kref;           /* Reference count */
 150        struct rpc_xprt_ops *   ops;            /* transport methods */
 151
 152        const struct rpc_timeout *timeout;      /* timeout parms */
 153        struct sockaddr_storage addr;           /* server address */
 154        size_t                  addrlen;        /* size of server address */
 155        int                     prot;           /* IP protocol */
 156
 157        unsigned long           cong;           /* current congestion */
 158        unsigned long           cwnd;           /* congestion window */
 159
 160        size_t                  max_payload;    /* largest RPC payload size,
 161                                                   in bytes */
 162        unsigned int            tsh_size;       /* size of transport specific
 163                                                   header */
 164
 165        struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 166        struct rpc_wait_queue   sending;        /* requests waiting to send */
 167        struct rpc_wait_queue   resend;         /* requests waiting to resend */
 168        struct rpc_wait_queue   pending;        /* requests in flight */
 169        struct rpc_wait_queue   backlog;        /* waiting for slot */
 170        struct list_head        free;           /* free slots */
 171        struct rpc_rqst *       slot;           /* slot table storage */
 172        unsigned int            max_reqs;       /* total slots */
 173        unsigned long           state;          /* transport state */
 174        unsigned char           shutdown   : 1, /* being shut down */
 175                                resvport   : 1; /* use a reserved port */
 176        unsigned int            bind_index;     /* bind function index */
 177
 178        /*
 179         * Connection of transports
 180         */
 181        unsigned long           bind_timeout,
 182                                reestablish_timeout;
 183        unsigned int            connect_cookie; /* A cookie that gets bumped
 184                                                   every time the transport
 185                                                   is reconnected */
 186
 187        /*
 188         * Disconnection of idle transports
 189         */
 190        struct work_struct      task_cleanup;
 191        struct timer_list       timer;
 192        unsigned long           last_used,
 193                                idle_timeout;
 194
 195        /*
 196         * Send stuff
 197         */
 198        spinlock_t              transport_lock; /* lock transport info */
 199        spinlock_t              reserve_lock;   /* lock slot table */
 200        u32                     xid;            /* Next XID value to use */
 201        struct rpc_task *       snd_task;       /* Task blocked in send */
 202        struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 203#if defined(CONFIG_NFS_V4_1)
 204        struct svc_serv         *bc_serv;       /* The RPC service which will */
 205                                                /* process the callback */
 206        unsigned int            bc_alloc_count; /* Total number of preallocs */
 207        spinlock_t              bc_pa_lock;     /* Protects the preallocated
 208                                                 * items */
 209        struct list_head        bc_pa_list;     /* List of preallocated
 210                                                 * backchannel rpc_rqst's */
 211#endif /* CONFIG_NFS_V4_1 */
 212        struct list_head        recv;
 213
 214        struct {
 215                unsigned long           bind_count,     /* total number of binds */
 216                                        connect_count,  /* total number of connects */
 217                                        connect_start,  /* connect start timestamp */
 218                                        connect_time,   /* jiffies waiting for connect */
 219                                        sends,          /* how many complete requests */
 220                                        recvs,          /* how many complete requests */
 221                                        bad_xids;       /* lookup_rqst didn't find XID */
 222
 223                unsigned long long      req_u,          /* average requests on the wire */
 224                                        bklog_u;        /* backlog queue utilization */
 225        } stat;
 226
 227        struct net              *xprt_net;
 228        const char              *address_strings[RPC_DISPLAY_MAX];
 229};
 230
 231#if defined(CONFIG_NFS_V4_1)
 232/*
 233 * Backchannel flags
 234 */
 235#define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 236                                                /* buffer in use */
 237#endif /* CONFIG_NFS_V4_1 */
 238
 239#if defined(CONFIG_NFS_V4_1)
 240static inline int bc_prealloc(struct rpc_rqst *req)
 241{
 242        return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 243}
 244#else
 245static inline int bc_prealloc(struct rpc_rqst *req)
 246{
 247        return 0;
 248}
 249#endif /* CONFIG_NFS_V4_1 */
 250
 251struct xprt_create {
 252        int                     ident;          /* XPRT_TRANSPORT identifier */
 253        struct net *            net;
 254        struct sockaddr *       srcaddr;        /* optional local address */
 255        struct sockaddr *       dstaddr;        /* remote peer address */
 256        size_t                  addrlen;
 257        struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 258};
 259
 260struct xprt_class {
 261        struct list_head        list;
 262        int                     ident;          /* XPRT_TRANSPORT identifier */
 263        struct rpc_xprt *       (*setup)(struct xprt_create *);
 264        struct module           *owner;
 265        char                    name[32];
 266};
 267
 268/*
 269 * Generic internal transport functions
 270 */
 271struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 272void                    xprt_connect(struct rpc_task *task);
 273void                    xprt_reserve(struct rpc_task *task);
 274int                     xprt_reserve_xprt(struct rpc_task *task);
 275int                     xprt_reserve_xprt_cong(struct rpc_task *task);
 276int                     xprt_prepare_transmit(struct rpc_task *task);
 277void                    xprt_transmit(struct rpc_task *task);
 278void                    xprt_end_transmit(struct rpc_task *task);
 279int                     xprt_adjust_timeout(struct rpc_rqst *req);
 280void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 281void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 282void                    xprt_release(struct rpc_task *task);
 283struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 284void                    xprt_put(struct rpc_xprt *xprt);
 285struct rpc_xprt *       xprt_alloc(struct net *net, int size, int max_req);
 286void                    xprt_free(struct rpc_xprt *);
 287
 288static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 289{
 290        return p + xprt->tsh_size;
 291}
 292
 293/*
 294 * Transport switch helper functions
 295 */
 296int                     xprt_register_transport(struct xprt_class *type);
 297int                     xprt_unregister_transport(struct xprt_class *type);
 298int                     xprt_load_transport(const char *);
 299void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 300void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 301void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 302void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 303void                    xprt_write_space(struct rpc_xprt *xprt);
 304void                    xprt_adjust_cwnd(struct rpc_task *task, int result);
 305struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 306void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 307void                    xprt_release_rqst_cong(struct rpc_task *task);
 308void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 309void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 310void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 311
 312/*
 313 * Reserved bit positions in xprt->state
 314 */
 315#define XPRT_LOCKED             (0)
 316#define XPRT_CONNECTED          (1)
 317#define XPRT_CONNECTING         (2)
 318#define XPRT_CLOSE_WAIT         (3)
 319#define XPRT_BOUND              (4)
 320#define XPRT_BINDING            (5)
 321#define XPRT_CLOSING            (6)
 322#define XPRT_CONNECTION_ABORT   (7)
 323#define XPRT_CONNECTION_CLOSE   (8)
 324#define XPRT_INITIALIZED        (9)
 325
 326static inline void xprt_set_connected(struct rpc_xprt *xprt)
 327{
 328        set_bit(XPRT_CONNECTED, &xprt->state);
 329}
 330
 331static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 332{
 333        clear_bit(XPRT_CONNECTED, &xprt->state);
 334}
 335
 336static inline int xprt_connected(struct rpc_xprt *xprt)
 337{
 338        return test_bit(XPRT_CONNECTED, &xprt->state);
 339}
 340
 341static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 342{
 343        return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 344}
 345
 346static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 347{
 348        return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 349}
 350
 351static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 352{
 353        smp_mb__before_clear_bit();
 354        clear_bit(XPRT_CONNECTING, &xprt->state);
 355        smp_mb__after_clear_bit();
 356}
 357
 358static inline int xprt_connecting(struct rpc_xprt *xprt)
 359{
 360        return test_bit(XPRT_CONNECTING, &xprt->state);
 361}
 362
 363static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 364{
 365        return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 366}
 367
 368static inline void xprt_set_bound(struct rpc_xprt *xprt)
 369{
 370        test_and_set_bit(XPRT_BOUND, &xprt->state);
 371}
 372
 373static inline int xprt_bound(struct rpc_xprt *xprt)
 374{
 375        return test_bit(XPRT_BOUND, &xprt->state);
 376}
 377
 378static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 379{
 380        clear_bit(XPRT_BOUND, &xprt->state);
 381}
 382
 383static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 384{
 385        smp_mb__before_clear_bit();
 386        clear_bit(XPRT_BINDING, &xprt->state);
 387        smp_mb__after_clear_bit();
 388}
 389
 390static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 391{
 392        return test_and_set_bit(XPRT_BINDING, &xprt->state);
 393}
 394
 395#endif /* __KERNEL__*/
 396
 397#endif /* _LINUX_SUNRPC_XPRT_H */
 398