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/sunrpc/sched.h>
  16 #include <linux/sunrpc/xdr.h>
  17
  18 /*
  19  * The transport code maintains an estimate on the maximum number of out-
  20  * standing RPC requests, using a smoothed version of the congestion
  21  * avoidance implemented in 44BSD. This is basically the Van Jacobson
  22  * congestion algorithm: If a retransmit occurs, the congestion window is
  23  * halved; otherwise, it is incremented by 1/cwnd when
  24  *
  25  *      -       a reply is received and
  26  *      -       a full number of requests are outstanding and
  27  *      -       the congestion window hasn't been updated recently.
  28  *
  29  * Upper procedures may check whether a request would block waiting for
  30  * a free RPC slot by using the RPC_CONGESTED() macro.
  31  */
  32 extern unsigned int xprt_udp_slot_table_entries;
  33 extern unsigned int xprt_tcp_slot_table_entries;
  34
  35 #define RPC_MIN_SLOT_TABLE      (2U)
  36 #define RPC_DEF_SLOT_TABLE      (16U)
  37 #define RPC_MAX_SLOT_TABLE      (128U)
  38
  39 #define RPC_CWNDSHIFT           (8U)
  40 #define RPC_CWNDSCALE           (1U << RPC_CWNDSHIFT)
  41 #define RPC_INITCWND            RPC_CWNDSCALE
  42 #define RPC_MAXCWND(xprt)       ((xprt)->max_reqs << RPC_CWNDSHIFT)
  43 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
  44
  45 /* Default timeout values */
  46 #define RPC_MAX_UDP_TIMEOUT     (60*HZ)
  47 #define RPC_MAX_TCP_TIMEOUT     (600*HZ)
  48
  49 /*
  50  * Wait duration for an RPC TCP connection to be established.  Solaris
  51  * NFS over TCP uses 60 seconds, for example, which is in line with how
  52  * long a server takes to reboot.
  53  */
  54 #define RPC_CONNECT_TIMEOUT     (60*HZ)
  55
  56 /*
  57  * Delay an arbitrary number of seconds before attempting to reconnect
  58  * after an error.
  59  */
  60 #define RPC_REESTABLISH_TIMEOUT (15*HZ)
  61
  62 /*
  63  * RPC transport idle timeout.
  64  */
  65 #define RPC_IDLE_DISCONNECT_TIMEOUT     (5*60*HZ)
  66
  67 /*
  68  * RPC call and reply header size as number of 32bit words (verifier
  69  * size computed separately)
  70  */
  71 #define RPC_CALLHDRSIZE         6
  72 #define RPC_REPHDRSIZE          4
  73
  74 /*
  75  * This describes a timeout strategy
  76  */
  77 struct rpc_timeout {
  78         unsigned long           to_initval,             /* initial timeout */
  79                                 to_maxval,              /* max timeout */
  80                                 to_increment;           /* if !exponential */
  81         unsigned int            to_retries;             /* max # of retries */
  82         unsigned char           to_exponential;
  83 };
  84
  85 /*
  86  * This describes a complete RPC request
  87  */
  88 struct rpc_rqst {
  89         /*
  90          * This is the user-visible part
  91          */
  92         struct rpc_xprt *       rq_xprt;                /* RPC client */
  93         struct xdr_buf          rq_snd_buf;             /* send buffer */
  94         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  95
  96         /*
  97          * This is the private part
  98          */
  99         struct rpc_task *       rq_task;        /* RPC task data */
 100         __u32                   rq_xid;         /* request XID */
 101         int                     rq_cong;        /* has incremented xprt->cong */
 102         int                     rq_received;    /* receive completed */
 103         u32                     rq_seqno;       /* gss seq no. used on req. */
 104
 105         struct list_head        rq_list;
 106
 107         struct xdr_buf          rq_private_buf;         /* The receive buffer
 108                                                          * used in the softirq.
 109                                                          */
 110         unsigned long           rq_majortimeo;  /* major timeout alarm */
 111         unsigned long           rq_timeout;     /* Current timeout value */
 112         unsigned int            rq_retries;     /* # of retries */
 113         /*
 114          * For authentication (e.g. auth_des)
 115          */
 116         u32                     rq_creddata[2];
 117
 118         /*
 119          * Partial send handling
 120          */
 121
 122         u32                     rq_bytes_sent;  /* Bytes we have sent */
 123
 124         unsigned long           rq_xtime;       /* when transmitted */
 125         int                     rq_ntrans;
 126 };
 127 #define rq_svec                 rq_snd_buf.head
 128 #define rq_slen                 rq_snd_buf.len
 129
 130 struct rpc_task;
 131 struct rpc_xprt;
 132
 133 struct rpc_xprt_ops {
 134         void            (*set_buffer_size)(struct rpc_xprt *xprt);
 135         void            (*connect)(struct rpc_task *task);
 136         int             (*send_request)(struct rpc_task *task);
 137         void            (*close)(struct rpc_xprt *xprt);
 138         void            (*destroy)(struct rpc_xprt *xprt);
 139 };
 140
 141 struct rpc_xprt {
 142         struct rpc_xprt_ops *   ops;            /* transport methods */
 143         struct socket *         sock;           /* BSD socket layer */
 144         struct sock *           inet;           /* INET layer */
 145
 146         struct rpc_timeout      timeout;        /* timeout parms */
 147         struct sockaddr_in      addr;           /* server address */
 148         int                     prot;           /* IP protocol */
 149
 150         unsigned long           cong;           /* current congestion */
 151         unsigned long           cwnd;           /* congestion window */
 152
 153         unsigned int            rcvsize,        /* transport rcv buffer size */
 154                                 sndsize;        /* transport send buffer size */
 155
 156         size_t                  max_payload;    /* largest RPC payload size,
 157                                                    in bytes */
 158         unsigned int            tsh_size;       /* size of transport specific
 159                                                    header */
 160
 161         struct rpc_wait_queue   sending;        /* requests waiting to send */
 162         struct rpc_wait_queue   resend;         /* requests waiting to resend */
 163         struct rpc_wait_queue   pending;        /* requests in flight */
 164         struct rpc_wait_queue   backlog;        /* waiting for slot */
 165         struct list_head        free;           /* free slots */
 166         struct rpc_rqst *       slot;           /* slot table storage */
 167         unsigned int            max_reqs;       /* total slots */
 168         unsigned long           state;          /* transport state */
 169         unsigned char           shutdown   : 1, /* being shut down */
 170                                 nocong     : 1, /* no congestion control */
 171                                 resvport   : 1; /* use a reserved port */
 172
 173         /*
 174          * XID
 175          */
 176         __u32                   xid;            /* Next XID value to use */
 177
 178         /*
 179          * State of TCP reply receive stuff
 180          */
 181         u32                     tcp_recm,       /* Fragment header */
 182                                 tcp_xid,        /* Current XID */
 183                                 tcp_reclen,     /* fragment length */
 184                                 tcp_offset;     /* fragment offset */
 185         unsigned long           tcp_copied,     /* copied to request */
 186                                 tcp_flags;
 187         /*
 188          * Connection of transports
 189          */
 190         struct work_struct      connect_worker;
 191         unsigned short          port;
 192         /*
 193          * Disconnection of idle transports
 194          */
 195         struct work_struct      task_cleanup;
 196         struct timer_list       timer;
 197         unsigned long           last_used;
 198
 199         /*
 200          * Send stuff
 201          */
 202         spinlock_t              transport_lock; /* lock transport info */
 203         spinlock_t              reserve_lock;   /* lock slot table */
 204         struct rpc_task *       snd_task;       /* Task blocked in send */
 205
 206         struct list_head        recv;
 207
 208
 209         void                    (*old_data_ready)(struct sock *, int);
 210         void                    (*old_state_change)(struct sock *);
 211         void                    (*old_write_space)(struct sock *);
 212
 213         wait_queue_head_t       cong_wait;
 214 };
 215
 216 #define XPRT_LAST_FRAG          (1 << 0)
 217 #define XPRT_COPY_RECM          (1 << 1)
 218 #define XPRT_COPY_XID           (1 << 2)
 219 #define XPRT_COPY_DATA          (1 << 3)
 220
 221 #ifdef __KERNEL__
 222
 223 /*
 224  * Transport operations used by ULPs
 225  */
 226 struct rpc_xprt *       xprt_create_proto(int proto, struct sockaddr_in *addr, struct rpc_timeout *to);
 227 void                    xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr);
 228
 229 /*
 230  * Generic internal transport functions
 231  */
 232 void                    xprt_connect(struct rpc_task *task);
 233 void                    xprt_reserve(struct rpc_task *task);
 234 int                     xprt_prepare_transmit(struct rpc_task *task);
 235 void                    xprt_transmit(struct rpc_task *task);
 236 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 237 void                    xprt_release(struct rpc_task *task);
 238 int                     xprt_destroy(struct rpc_xprt *xprt);
 239
 240 static inline u32 *xprt_skip_transport_header(struct rpc_xprt *xprt, u32 *p)
 241 {
 242         return p + xprt->tsh_size;
 243 }
 244
 245 /*
 246  * Transport switch helper functions
 247  */
 248 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 249 void                    xprt_wait_for_buffer_space(struct rpc_task *task);
 250 void                    xprt_write_space(struct rpc_xprt *xprt);
 251 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid);
 252 void                    xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied);
 253 void                    xprt_disconnect(struct rpc_xprt *xprt);
 254
 255 /*
 256  * Socket transport setup operations
 257  */
 258 int                     xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to);
 259 int                     xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to);
 260
 261 /*
 262  * Reserved bit positions in xprt->state
 263  */
 264 #define XPRT_LOCKED             (0)
 265 #define XPRT_CONNECTED          (1)
 266 #define XPRT_CONNECTING         (2)
 267
 268 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 269 {
 270         set_bit(XPRT_CONNECTED, &xprt->state);
 271 }
 272
 273 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 274 {
 275         clear_bit(XPRT_CONNECTED, &xprt->state);
 276 }
 277
 278 static inline int xprt_connected(struct rpc_xprt *xprt)
 279 {
 280         return test_bit(XPRT_CONNECTED, &xprt->state);
 281 }
 282
 283 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 284 {
 285         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 286 }
 287
 288 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 289 {
 290         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 291 }
 292
 293 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 294 {
 295         smp_mb__before_clear_bit();
 296         clear_bit(XPRT_CONNECTING, &xprt->state);
 297         smp_mb__after_clear_bit();
 298 }
 299
 300 static inline int xprt_connecting(struct rpc_xprt *xprt)
 301 {
 302         return test_bit(XPRT_CONNECTING, &xprt->state);
 303 }
 304
 305 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 306 {
 307         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 308 }
 309
 310 #endif /* __KERNEL__*/
 311
 312 #endif /* _LINUX_SUNRPC_XPRT_H */