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/kref.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_LIMIT        (65536U)
  26 #define RPC_MAX_SLOT_TABLE      RPC_MAX_SLOT_TABLE_LIMIT
  27
  28 #define RPC_CWNDSHIFT           (8U)
  29 #define RPC_CWNDSCALE           (1U << RPC_CWNDSHIFT)
  30 #define RPC_INITCWND            RPC_CWNDSCALE
  31 #define RPC_MAXCWND(xprt)       ((xprt)->max_reqs << RPC_CWNDSHIFT)
  32 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
  33
  34 /*
  35  * This describes a timeout strategy
  36  */
  37 struct rpc_timeout {
  38         unsigned long           to_initval,             /* initial timeout */
  39                                 to_maxval,              /* max timeout */
  40                                 to_increment;           /* if !exponential */
  41         unsigned int            to_retries;             /* max # of retries */
  42         unsigned char           to_exponential;
  43 };
  44
  45 enum rpc_display_format_t {
  46         RPC_DISPLAY_ADDR = 0,
  47         RPC_DISPLAY_PORT,
  48         RPC_DISPLAY_PROTO,
  49         RPC_DISPLAY_HEX_ADDR,
  50         RPC_DISPLAY_HEX_PORT,
  51         RPC_DISPLAY_NETID,
  52         RPC_DISPLAY_MAX,
  53 };
  54
  55 struct rpc_task;
  56 struct rpc_xprt;
  57 struct seq_file;
  58 struct svc_serv;
  59 struct net;
  60
  61 /*
  62  * This describes a complete RPC request
  63  */
  64 struct rpc_rqst {
  65         /*
  66          * This is the user-visible part
  67          */
  68         struct rpc_xprt *       rq_xprt;                /* RPC client */
  69         struct xdr_buf          rq_snd_buf;             /* send buffer */
  70         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  71
  72         /*
  73          * This is the private part
  74          */
  75         struct rpc_task *       rq_task;        /* RPC task data */
  76         struct rpc_cred *       rq_cred;        /* Bound cred */
  77         __be32                  rq_xid;         /* request XID */
  78         int                     rq_cong;        /* has incremented xprt->cong */
  79         u32                     rq_seqno;       /* gss seq no. used on req. */
  80         int                     rq_enc_pages_num;
  81         struct page             **rq_enc_pages; /* scratch pages for use by
  82                                                    gss privacy code */
  83         void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  84         struct list_head        rq_list;
  85
  86         __u32 *                 rq_buffer;      /* XDR encode buffer */
  87         size_t                  rq_callsize,
  88                                 rq_rcvsize;
  89         size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  90         size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  91                                                         /* received */
  92
  93         struct xdr_buf          rq_private_buf;         /* The receive buffer
  94                                                          * used in the softirq.
  95                                                          */
  96         unsigned long           rq_majortimeo;  /* major timeout alarm */
  97         unsigned long           rq_timeout;     /* Current timeout value */
  98         ktime_t                 rq_rtt;         /* round-trip time */
  99         unsigned int            rq_retries;     /* # of retries */
 100         unsigned int            rq_connect_cookie;
 101                                                 /* A cookie used to track the
 102                                                    state of the transport
 103                                                    connection */
 104
 105         /*
 106          * Partial send handling
 107          */
 108         u32                     rq_bytes_sent;  /* Bytes we have sent */
 109
 110         ktime_t                 rq_xtime;       /* transmit time stamp */
 111         int                     rq_ntrans;
 112
 113 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 114         struct list_head        rq_bc_list;     /* Callback service list */
 115         unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 116         struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 117 #endif /* CONFIG_SUNRPC_BACKCHANEL */
 118 };
 119 #define rq_svec                 rq_snd_buf.head
 120 #define rq_slen                 rq_snd_buf.len
 121
 122 struct rpc_xprt_ops {
 123         void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 124         int             (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 125         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 126         void            (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
 127         void            (*rpcbind)(struct rpc_task *task);
 128         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 129         void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 130         void *          (*buf_alloc)(struct rpc_task *task, size_t size);
 131         void            (*buf_free)(void *buffer);
 132         int             (*send_request)(struct rpc_task *task);
 133         void            (*set_retrans_timeout)(struct rpc_task *task);
 134         void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 135         void            (*release_request)(struct rpc_task *task);
 136         void            (*close)(struct rpc_xprt *xprt);
 137         void            (*destroy)(struct rpc_xprt *xprt);
 138         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 139         int             (*enable_swap)(struct rpc_xprt *xprt);
 140         void            (*disable_swap)(struct rpc_xprt *xprt);
 141         void            (*inject_disconnect)(struct rpc_xprt *xprt);
 142         int             (*bc_setup)(struct rpc_xprt *xprt,
 143                                     unsigned int min_reqs);
 144         int             (*bc_up)(struct svc_serv *serv, struct net *net);
 145         size_t          (*bc_maxpayload)(struct rpc_xprt *xprt);
 146         void            (*bc_free_rqst)(struct rpc_rqst *rqst);
 147         void            (*bc_destroy)(struct rpc_xprt *xprt,
 148                                       unsigned int max_reqs);
 149 };
 150
 151 /*
 152  * RPC transport identifiers
 153  *
 154  * To preserve compatibility with the historical use of raw IP protocol
 155  * id's for transport selection, UDP and TCP identifiers are specified
 156  * with the previous values. No such restriction exists for new transports,
 157  * except that they may not collide with these values (17 and 6,
 158  * respectively).
 159  */
 160 #define XPRT_TRANSPORT_BC       (1 << 31)
 161 enum xprt_transports {
 162         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 163         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 164         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 165         XPRT_TRANSPORT_RDMA     = 256,
 166         XPRT_TRANSPORT_BC_RDMA  = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
 167         XPRT_TRANSPORT_LOCAL    = 257,
 168 };
 169
 170 struct rpc_xprt {
 171         struct kref             kref;           /* Reference count */
 172         struct rpc_xprt_ops *   ops;            /* transport methods */
 173
 174         const struct rpc_timeout *timeout;      /* timeout parms */
 175         struct sockaddr_storage addr;           /* server address */
 176         size_t                  addrlen;        /* size of server address */
 177         int                     prot;           /* IP protocol */
 178
 179         unsigned long           cong;           /* current congestion */
 180         unsigned long           cwnd;           /* congestion window */
 181
 182         size_t                  max_payload;    /* largest RPC payload size,
 183                                                    in bytes */
 184         unsigned int            tsh_size;       /* size of transport specific
 185                                                    header */
 186
 187         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 188         struct rpc_wait_queue   sending;        /* requests waiting to send */
 189         struct rpc_wait_queue   pending;        /* requests in flight */
 190         struct rpc_wait_queue   backlog;        /* waiting for slot */
 191         struct list_head        free;           /* free slots */
 192         unsigned int            max_reqs;       /* max number of slots */
 193         unsigned int            min_reqs;       /* min number of slots */
 194         atomic_t                num_reqs;       /* total slots */
 195         unsigned long           state;          /* transport state */
 196         unsigned char           resvport   : 1; /* use a reserved port */
 197         atomic_t                swapper;        /* we're swapping over this
 198                                                    transport */
 199         unsigned int            bind_index;     /* bind function index */
 200
 201         /*
 202          * Multipath
 203          */
 204         struct list_head        xprt_switch;
 205
 206         /*
 207          * Connection of transports
 208          */
 209         unsigned long           bind_timeout,
 210                                 reestablish_timeout;
 211         unsigned int            connect_cookie; /* A cookie that gets bumped
 212                                                    every time the transport
 213                                                    is reconnected */
 214
 215         /*
 216          * Disconnection of idle transports
 217          */
 218         struct work_struct      task_cleanup;
 219         struct timer_list       timer;
 220         unsigned long           last_used,
 221                                 idle_timeout,
 222                                 max_reconnect_timeout;
 223
 224         /*
 225          * Send stuff
 226          */
 227         spinlock_t              transport_lock; /* lock transport info */
 228         spinlock_t              reserve_lock;   /* lock slot table */
 229         u32                     xid;            /* Next XID value to use */
 230         struct rpc_task *       snd_task;       /* Task blocked in send */
 231         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 232 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 233         struct svc_serv         *bc_serv;       /* The RPC service which will */
 234                                                 /* process the callback */
 235         int                     bc_alloc_count; /* Total number of preallocs */
 236         atomic_t                bc_free_slots;
 237         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 238                                                  * items */
 239         struct list_head        bc_pa_list;     /* List of preallocated
 240                                                  * backchannel rpc_rqst's */
 241 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 242         struct list_head        recv;
 243
 244         struct {
 245                 unsigned long           bind_count,     /* total number of binds */
 246                                         connect_count,  /* total number of connects */
 247                                         connect_start,  /* connect start timestamp */
 248                                         connect_time,   /* jiffies waiting for connect */
 249                                         sends,          /* how many complete requests */
 250                                         recvs,          /* how many complete requests */
 251                                         bad_xids,       /* lookup_rqst didn't find XID */
 252                                         max_slots;      /* max rpc_slots used */
 253
 254                 unsigned long long      req_u,          /* average requests on the wire */
 255                                         bklog_u,        /* backlog queue utilization */
 256                                         sending_u,      /* send q utilization */
 257                                         pending_u;      /* pend q utilization */
 258         } stat;
 259
 260         struct net              *xprt_net;
 261         const char              *servername;
 262         const char              *address_strings[RPC_DISPLAY_MAX];
 263 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 264         struct dentry           *debugfs;               /* debugfs directory */
 265         atomic_t                inject_disconnect;
 266 #endif
 267         struct rcu_head         rcu;
 268 };
 269
 270 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 271 /*
 272  * Backchannel flags
 273  */
 274 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 275                                                 /* buffer in use */
 276 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 277
 278 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 279 static inline int bc_prealloc(struct rpc_rqst *req)
 280 {
 281         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 282 }
 283 #else
 284 static inline int bc_prealloc(struct rpc_rqst *req)
 285 {
 286         return 0;
 287 }
 288 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 289
 290 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 291 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 292
 293 struct xprt_create {
 294         int                     ident;          /* XPRT_TRANSPORT identifier */
 295         struct net *            net;
 296         struct sockaddr *       srcaddr;        /* optional local address */
 297         struct sockaddr *       dstaddr;        /* remote peer address */
 298         size_t                  addrlen;
 299         const char              *servername;
 300         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 301         struct rpc_xprt_switch  *bc_xps;
 302         unsigned int            flags;
 303 };
 304
 305 struct xprt_class {
 306         struct list_head        list;
 307         int                     ident;          /* XPRT_TRANSPORT identifier */
 308         struct rpc_xprt *       (*setup)(struct xprt_create *);
 309         struct module           *owner;
 310         char                    name[32];
 311 };
 312
 313 /*
 314  * Generic internal transport functions
 315  */
 316 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 317 void                    xprt_connect(struct rpc_task *task);
 318 void                    xprt_reserve(struct rpc_task *task);
 319 void                    xprt_retry_reserve(struct rpc_task *task);
 320 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 321 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 322 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 323 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 324 bool                    xprt_prepare_transmit(struct rpc_task *task);
 325 void                    xprt_transmit(struct rpc_task *task);
 326 void                    xprt_end_transmit(struct rpc_task *task);
 327 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 328 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 329 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 330 void                    xprt_release(struct rpc_task *task);
 331 struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 332 void                    xprt_put(struct rpc_xprt *xprt);
 333 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 334                                 unsigned int num_prealloc,
 335                                 unsigned int max_req);
 336 void                    xprt_free(struct rpc_xprt *);
 337
 338 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 339 {
 340         return p + xprt->tsh_size;
 341 }
 342
 343 static inline int
 344 xprt_enable_swap(struct rpc_xprt *xprt)
 345 {
 346         return xprt->ops->enable_swap(xprt);
 347 }
 348
 349 static inline void
 350 xprt_disable_swap(struct rpc_xprt *xprt)
 351 {
 352         xprt->ops->disable_swap(xprt);
 353 }
 354
 355 /*
 356  * Transport switch helper functions
 357  */
 358 int                     xprt_register_transport(struct xprt_class *type);
 359 int                     xprt_unregister_transport(struct xprt_class *type);
 360 int                     xprt_load_transport(const char *);
 361 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 362 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 363 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 364 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 365 void                    xprt_write_space(struct rpc_xprt *xprt);
 366 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 367 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 368 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 369 void                    xprt_release_rqst_cong(struct rpc_task *task);
 370 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 371 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 372 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 373
 374 bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 375 void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 376
 377 /*
 378  * Reserved bit positions in xprt->state
 379  */
 380 #define XPRT_LOCKED             (0)
 381 #define XPRT_CONNECTED          (1)
 382 #define XPRT_CONNECTING         (2)
 383 #define XPRT_CLOSE_WAIT         (3)
 384 #define XPRT_BOUND              (4)
 385 #define XPRT_BINDING            (5)
 386 #define XPRT_CLOSING            (6)
 387 #define XPRT_CONGESTED          (9)
 388
 389 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 390 {
 391         set_bit(XPRT_CONNECTED, &xprt->state);
 392 }
 393
 394 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 395 {
 396         clear_bit(XPRT_CONNECTED, &xprt->state);
 397 }
 398
 399 static inline int xprt_connected(struct rpc_xprt *xprt)
 400 {
 401         return test_bit(XPRT_CONNECTED, &xprt->state);
 402 }
 403
 404 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 405 {
 406         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 407 }
 408
 409 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 410 {
 411         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 412 }
 413
 414 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 415 {
 416         smp_mb__before_atomic();
 417         clear_bit(XPRT_CONNECTING, &xprt->state);
 418         smp_mb__after_atomic();
 419 }
 420
 421 static inline int xprt_connecting(struct rpc_xprt *xprt)
 422 {
 423         return test_bit(XPRT_CONNECTING, &xprt->state);
 424 }
 425
 426 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 427 {
 428         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 429 }
 430
 431 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 432 {
 433         test_and_set_bit(XPRT_BOUND, &xprt->state);
 434 }
 435
 436 static inline int xprt_bound(struct rpc_xprt *xprt)
 437 {
 438         return test_bit(XPRT_BOUND, &xprt->state);
 439 }
 440
 441 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 442 {
 443         clear_bit(XPRT_BOUND, &xprt->state);
 444 }
 445
 446 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 447 {
 448         smp_mb__before_atomic();
 449         clear_bit(XPRT_BINDING, &xprt->state);
 450         smp_mb__after_atomic();
 451 }
 452
 453 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 454 {
 455         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 456 }
 457
 458 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 459 extern unsigned int rpc_inject_disconnect;
 460 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 461 {
 462         if (!rpc_inject_disconnect)
 463                 return;
 464         if (atomic_dec_return(&xprt->inject_disconnect))
 465                 return;
 466         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 467         xprt->ops->inject_disconnect(xprt);
 468 }
 469 #else
 470 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 471 {
 472 }
 473 #endif
 474
 475 #endif /* __KERNEL__*/
 476
 477 #endif /* _LINUX_SUNRPC_XPRT_H */