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         void            (*bc_free_rqst)(struct rpc_rqst *rqst);
 146         void            (*bc_destroy)(struct rpc_xprt *xprt,
 147                                       unsigned int max_reqs);
 148 };
 149
 150 /*
 151  * RPC transport identifiers
 152  *
 153  * To preserve compatibility with the historical use of raw IP protocol
 154  * id's for transport selection, UDP and TCP identifiers are specified
 155  * with the previous values. No such restriction exists for new transports,
 156  * except that they may not collide with these values (17 and 6,
 157  * respectively).
 158  */
 159 #define XPRT_TRANSPORT_BC       (1 << 31)
 160 enum xprt_transports {
 161         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 162         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 163         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 164         XPRT_TRANSPORT_RDMA     = 256,
 165         XPRT_TRANSPORT_BC_RDMA  = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
 166         XPRT_TRANSPORT_LOCAL    = 257,
 167 };
 168
 169 struct rpc_xprt {
 170         struct kref             kref;           /* Reference count */
 171         struct rpc_xprt_ops *   ops;            /* transport methods */
 172
 173         const struct rpc_timeout *timeout;      /* timeout parms */
 174         struct sockaddr_storage addr;           /* server address */
 175         size_t                  addrlen;        /* size of server address */
 176         int                     prot;           /* IP protocol */
 177
 178         unsigned long           cong;           /* current congestion */
 179         unsigned long           cwnd;           /* congestion window */
 180
 181         size_t                  max_payload;    /* largest RPC payload size,
 182                                                    in bytes */
 183         unsigned int            tsh_size;       /* size of transport specific
 184                                                    header */
 185
 186         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 187         struct rpc_wait_queue   sending;        /* requests waiting to send */
 188         struct rpc_wait_queue   pending;        /* requests in flight */
 189         struct rpc_wait_queue   backlog;        /* waiting for slot */
 190         struct list_head        free;           /* free slots */
 191         unsigned int            max_reqs;       /* max number of slots */
 192         unsigned int            min_reqs;       /* min number of slots */
 193         atomic_t                num_reqs;       /* total slots */
 194         unsigned long           state;          /* transport state */
 195         unsigned char           resvport   : 1; /* use a reserved port */
 196         atomic_t                swapper;        /* we're swapping over this
 197                                                    transport */
 198         unsigned int            bind_index;     /* bind function index */
 199
 200         /*
 201          * Multipath
 202          */
 203         struct list_head        xprt_switch;
 204
 205         /*
 206          * Connection of transports
 207          */
 208         unsigned long           bind_timeout,
 209                                 reestablish_timeout;
 210         unsigned int            connect_cookie; /* A cookie that gets bumped
 211                                                    every time the transport
 212                                                    is reconnected */
 213
 214         /*
 215          * Disconnection of idle transports
 216          */
 217         struct work_struct      task_cleanup;
 218         struct timer_list       timer;
 219         unsigned long           last_used,
 220                                 idle_timeout;
 221
 222         /*
 223          * Send stuff
 224          */
 225         spinlock_t              transport_lock; /* lock transport info */
 226         spinlock_t              reserve_lock;   /* lock slot table */
 227         u32                     xid;            /* Next XID value to use */
 228         struct rpc_task *       snd_task;       /* Task blocked in send */
 229         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 230 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 231         struct svc_serv         *bc_serv;       /* The RPC service which will */
 232                                                 /* process the callback */
 233         int                     bc_alloc_count; /* Total number of preallocs */
 234         atomic_t                bc_free_slots;
 235         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 236                                                  * items */
 237         struct list_head        bc_pa_list;     /* List of preallocated
 238                                                  * backchannel rpc_rqst's */
 239 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 240         struct list_head        recv;
 241
 242         struct {
 243                 unsigned long           bind_count,     /* total number of binds */
 244                                         connect_count,  /* total number of connects */
 245                                         connect_start,  /* connect start timestamp */
 246                                         connect_time,   /* jiffies waiting for connect */
 247                                         sends,          /* how many complete requests */
 248                                         recvs,          /* how many complete requests */
 249                                         bad_xids,       /* lookup_rqst didn't find XID */
 250                                         max_slots;      /* max rpc_slots used */
 251
 252                 unsigned long long      req_u,          /* average requests on the wire */
 253                                         bklog_u,        /* backlog queue utilization */
 254                                         sending_u,      /* send q utilization */
 255                                         pending_u;      /* pend q utilization */
 256         } stat;
 257
 258         struct net              *xprt_net;
 259         const char              *servername;
 260         const char              *address_strings[RPC_DISPLAY_MAX];
 261 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 262         struct dentry           *debugfs;               /* debugfs directory */
 263         atomic_t                inject_disconnect;
 264 #endif
 265         struct rcu_head         rcu;
 266 };
 267
 268 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 269 /*
 270  * Backchannel flags
 271  */
 272 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 273                                                 /* buffer in use */
 274 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 275
 276 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 277 static inline int bc_prealloc(struct rpc_rqst *req)
 278 {
 279         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 280 }
 281 #else
 282 static inline int bc_prealloc(struct rpc_rqst *req)
 283 {
 284         return 0;
 285 }
 286 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 287
 288 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 289 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 290
 291 struct xprt_create {
 292         int                     ident;          /* XPRT_TRANSPORT identifier */
 293         struct net *            net;
 294         struct sockaddr *       srcaddr;        /* optional local address */
 295         struct sockaddr *       dstaddr;        /* remote peer address */
 296         size_t                  addrlen;
 297         const char              *servername;
 298         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 299         unsigned int            flags;
 300 };
 301
 302 struct xprt_class {
 303         struct list_head        list;
 304         int                     ident;          /* XPRT_TRANSPORT identifier */
 305         struct rpc_xprt *       (*setup)(struct xprt_create *);
 306         struct module           *owner;
 307         char                    name[32];
 308 };
 309
 310 /*
 311  * Generic internal transport functions
 312  */
 313 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 314 void                    xprt_connect(struct rpc_task *task);
 315 void                    xprt_reserve(struct rpc_task *task);
 316 void                    xprt_retry_reserve(struct rpc_task *task);
 317 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 318 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 319 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 320 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 321 bool                    xprt_prepare_transmit(struct rpc_task *task);
 322 void                    xprt_transmit(struct rpc_task *task);
 323 void                    xprt_end_transmit(struct rpc_task *task);
 324 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 325 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 326 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 327 void                    xprt_release(struct rpc_task *task);
 328 struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 329 void                    xprt_put(struct rpc_xprt *xprt);
 330 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 331                                 unsigned int num_prealloc,
 332                                 unsigned int max_req);
 333 void                    xprt_free(struct rpc_xprt *);
 334
 335 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 336 {
 337         return p + xprt->tsh_size;
 338 }
 339
 340 static inline int
 341 xprt_enable_swap(struct rpc_xprt *xprt)
 342 {
 343         return xprt->ops->enable_swap(xprt);
 344 }
 345
 346 static inline void
 347 xprt_disable_swap(struct rpc_xprt *xprt)
 348 {
 349         xprt->ops->disable_swap(xprt);
 350 }
 351
 352 /*
 353  * Transport switch helper functions
 354  */
 355 int                     xprt_register_transport(struct xprt_class *type);
 356 int                     xprt_unregister_transport(struct xprt_class *type);
 357 int                     xprt_load_transport(const char *);
 358 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 359 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 360 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 361 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 362 void                    xprt_write_space(struct rpc_xprt *xprt);
 363 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 364 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 365 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 366 void                    xprt_release_rqst_cong(struct rpc_task *task);
 367 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 368 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 369 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 370
 371 bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 372 void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 373
 374 /*
 375  * Reserved bit positions in xprt->state
 376  */
 377 #define XPRT_LOCKED             (0)
 378 #define XPRT_CONNECTED          (1)
 379 #define XPRT_CONNECTING         (2)
 380 #define XPRT_CLOSE_WAIT         (3)
 381 #define XPRT_BOUND              (4)
 382 #define XPRT_BINDING            (5)
 383 #define XPRT_CLOSING            (6)
 384 #define XPRT_CONGESTED          (9)
 385
 386 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 387 {
 388         set_bit(XPRT_CONNECTED, &xprt->state);
 389 }
 390
 391 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 392 {
 393         clear_bit(XPRT_CONNECTED, &xprt->state);
 394 }
 395
 396 static inline int xprt_connected(struct rpc_xprt *xprt)
 397 {
 398         return test_bit(XPRT_CONNECTED, &xprt->state);
 399 }
 400
 401 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 402 {
 403         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 404 }
 405
 406 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 407 {
 408         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 409 }
 410
 411 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 412 {
 413         smp_mb__before_atomic();
 414         clear_bit(XPRT_CONNECTING, &xprt->state);
 415         smp_mb__after_atomic();
 416 }
 417
 418 static inline int xprt_connecting(struct rpc_xprt *xprt)
 419 {
 420         return test_bit(XPRT_CONNECTING, &xprt->state);
 421 }
 422
 423 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 424 {
 425         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 426 }
 427
 428 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 429 {
 430         test_and_set_bit(XPRT_BOUND, &xprt->state);
 431 }
 432
 433 static inline int xprt_bound(struct rpc_xprt *xprt)
 434 {
 435         return test_bit(XPRT_BOUND, &xprt->state);
 436 }
 437
 438 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 439 {
 440         clear_bit(XPRT_BOUND, &xprt->state);
 441 }
 442
 443 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 444 {
 445         smp_mb__before_atomic();
 446         clear_bit(XPRT_BINDING, &xprt->state);
 447         smp_mb__after_atomic();
 448 }
 449
 450 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 451 {
 452         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 453 }
 454
 455 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 456 extern unsigned int rpc_inject_disconnect;
 457 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 458 {
 459         if (!rpc_inject_disconnect)
 460                 return;
 461         if (atomic_dec_return(&xprt->inject_disconnect))
 462                 return;
 463         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 464         xprt->ops->inject_disconnect(xprt);
 465 }
 466 #else
 467 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 468 {
 469 }
 470 #endif
 471
 472 #endif /* __KERNEL__*/
 473
 474 #endif /* _LINUX_SUNRPC_XPRT_H */