include/linux/sunrpc/xprt.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  linux/include/linux/sunrpc/xprt.h
   4  *
   5  *  Declarations for the RPC transport interface.
   6  *
   7  *  Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   8  */
   9
  10 #ifndef _LINUX_SUNRPC_XPRT_H
  11 #define _LINUX_SUNRPC_XPRT_H
  12
  13 #include <linux/uio.h>
  14 #include <linux/socket.h>
  15 #include <linux/in.h>
  16 #include <linux/ktime.h>
  17 #include <linux/kref.h>
  18 #include <linux/sunrpc/sched.h>
  19 #include <linux/sunrpc/xdr.h>
  20 #include <linux/sunrpc/msg_prot.h>
  21
  22 #ifdef __KERNEL__
  23
  24 #define RPC_MIN_SLOT_TABLE      (2U)
  25 #define RPC_DEF_SLOT_TABLE      (16U)
  26 #define RPC_MAX_SLOT_TABLE_LIMIT        (65536U)
  27 #define RPC_MAX_SLOT_TABLE      RPC_MAX_SLOT_TABLE_LIMIT
  28
  29 #define RPC_CWNDSHIFT           (8U)
  30 #define RPC_CWNDSCALE           (1U << RPC_CWNDSHIFT)
  31 #define RPC_INITCWND            RPC_CWNDSCALE
  32 #define RPC_MAXCWND(xprt)       ((xprt)->max_reqs << RPC_CWNDSHIFT)
  33 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
  34
  35 /*
  36  * This describes a timeout strategy
  37  */
  38 struct rpc_timeout {
  39         unsigned long           to_initval,             /* initial timeout */
  40                                 to_maxval,              /* max timeout */
  41                                 to_increment;           /* if !exponential */
  42         unsigned int            to_retries;             /* max # of retries */
  43         unsigned char           to_exponential;
  44 };
  45
  46 enum rpc_display_format_t {
  47         RPC_DISPLAY_ADDR = 0,
  48         RPC_DISPLAY_PORT,
  49         RPC_DISPLAY_PROTO,
  50         RPC_DISPLAY_HEX_ADDR,
  51         RPC_DISPLAY_HEX_PORT,
  52         RPC_DISPLAY_NETID,
  53         RPC_DISPLAY_MAX,
  54 };
  55
  56 struct rpc_task;
  57 struct rpc_xprt;
  58 struct seq_file;
  59 struct svc_serv;
  60 struct net;
  61
  62 /*
  63  * This describes a complete RPC request
  64  */
  65 struct rpc_rqst {
  66         /*
  67          * This is the user-visible part
  68          */
  69         struct rpc_xprt *       rq_xprt;                /* RPC client */
  70         struct xdr_buf          rq_snd_buf;             /* send buffer */
  71         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  72
  73         /*
  74          * This is the private part
  75          */
  76         struct rpc_task *       rq_task;        /* RPC task data */
  77         struct rpc_cred *       rq_cred;        /* Bound cred */
  78         __be32                  rq_xid;         /* request XID */
  79         int                     rq_cong;        /* has incremented xprt->cong */
  80         u32                     rq_seqno;       /* gss seq no. used on req. */
  81         int                     rq_enc_pages_num;
  82         struct page             **rq_enc_pages; /* scratch pages for use by
  83                                                    gss privacy code */
  84         void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  85         struct list_head        rq_list;
  86
  87         void                    *rq_xprtdata;   /* Per-xprt private data */
  88         void                    *rq_buffer;     /* Call XDR encode buffer */
  89         size_t                  rq_callsize;
  90         void                    *rq_rbuffer;    /* Reply XDR decode buffer */
  91         size_t                  rq_rcvsize;
  92         size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  93         size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  94                                                         /* received */
  95
  96         struct xdr_buf          rq_private_buf;         /* The receive buffer
  97                                                          * used in the softirq.
  98                                                          */
  99         unsigned long           rq_majortimeo;  /* major timeout alarm */
 100         unsigned long           rq_timeout;     /* Current timeout value */
 101         ktime_t                 rq_rtt;         /* round-trip time */
 102         unsigned int            rq_retries;     /* # of retries */
 103         unsigned int            rq_connect_cookie;
 104                                                 /* A cookie used to track the
 105                                                    state of the transport
 106                                                    connection */
 107
 108         /*
 109          * Partial send handling
 110          */
 111         u32                     rq_bytes_sent;  /* Bytes we have sent */
 112
 113         ktime_t                 rq_xtime;       /* transmit time stamp */
 114         int                     rq_ntrans;
 115
 116 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 117         struct list_head        rq_bc_list;     /* Callback service list */
 118         unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 119         struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 120 #endif /* CONFIG_SUNRPC_BACKCHANEL */
 121 };
 122 #define rq_svec                 rq_snd_buf.head
 123 #define rq_slen                 rq_snd_buf.len
 124
 125 struct rpc_xprt_ops {
 126         void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 127         int             (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 128         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 129         void            (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
 130         void            (*rpcbind)(struct rpc_task *task);
 131         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 132         void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 133         int             (*buf_alloc)(struct rpc_task *task);
 134         void            (*buf_free)(struct rpc_task *task);
 135         int             (*send_request)(struct rpc_task *task);
 136         void            (*set_retrans_timeout)(struct rpc_task *task);
 137         void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 138         void            (*release_request)(struct rpc_task *task);
 139         void            (*close)(struct rpc_xprt *xprt);
 140         void            (*destroy)(struct rpc_xprt *xprt);
 141         void            (*set_connect_timeout)(struct rpc_xprt *xprt,
 142                                         unsigned long connect_timeout,
 143                                         unsigned long reconnect_timeout);
 144         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 145         int             (*enable_swap)(struct rpc_xprt *xprt);
 146         void            (*disable_swap)(struct rpc_xprt *xprt);
 147         void            (*inject_disconnect)(struct rpc_xprt *xprt);
 148         int             (*bc_setup)(struct rpc_xprt *xprt,
 149                                     unsigned int min_reqs);
 150         int             (*bc_up)(struct svc_serv *serv, struct net *net);
 151         size_t          (*bc_maxpayload)(struct rpc_xprt *xprt);
 152         void            (*bc_free_rqst)(struct rpc_rqst *rqst);
 153         void            (*bc_destroy)(struct rpc_xprt *xprt,
 154                                       unsigned int max_reqs);
 155 };
 156
 157 /*
 158  * RPC transport identifiers
 159  *
 160  * To preserve compatibility with the historical use of raw IP protocol
 161  * id's for transport selection, UDP and TCP identifiers are specified
 162  * with the previous values. No such restriction exists for new transports,
 163  * except that they may not collide with these values (17 and 6,
 164  * respectively).
 165  */
 166 #define XPRT_TRANSPORT_BC       (1 << 31)
 167 enum xprt_transports {
 168         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 169         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 170         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 171         XPRT_TRANSPORT_RDMA     = 256,
 172         XPRT_TRANSPORT_BC_RDMA  = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
 173         XPRT_TRANSPORT_LOCAL    = 257,
 174 };
 175
 176 struct rpc_xprt {
 177         struct kref             kref;           /* Reference count */
 178         const struct rpc_xprt_ops *ops;         /* transport methods */
 179
 180         const struct rpc_timeout *timeout;      /* timeout parms */
 181         struct sockaddr_storage addr;           /* server address */
 182         size_t                  addrlen;        /* size of server address */
 183         int                     prot;           /* IP protocol */
 184
 185         unsigned long           cong;           /* current congestion */
 186         unsigned long           cwnd;           /* congestion window */
 187
 188         size_t                  max_payload;    /* largest RPC payload size,
 189                                                    in bytes */
 190         unsigned int            tsh_size;       /* size of transport specific
 191                                                    header */
 192
 193         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 194         struct rpc_wait_queue   sending;        /* requests waiting to send */
 195         struct rpc_wait_queue   pending;        /* requests in flight */
 196         struct rpc_wait_queue   backlog;        /* waiting for slot */
 197         struct list_head        free;           /* free slots */
 198         unsigned int            max_reqs;       /* max number of slots */
 199         unsigned int            min_reqs;       /* min number of slots */
 200         atomic_t                num_reqs;       /* total slots */
 201         unsigned long           state;          /* transport state */
 202         unsigned char           resvport   : 1; /* use a reserved port */
 203         atomic_t                swapper;        /* we're swapping over this
 204                                                    transport */
 205         unsigned int            bind_index;     /* bind function index */
 206
 207         /*
 208          * Multipath
 209          */
 210         struct list_head        xprt_switch;
 211
 212         /*
 213          * Connection of transports
 214          */
 215         unsigned long           bind_timeout,
 216                                 reestablish_timeout;
 217         unsigned int            connect_cookie; /* A cookie that gets bumped
 218                                                    every time the transport
 219                                                    is reconnected */
 220
 221         /*
 222          * Disconnection of idle transports
 223          */
 224         struct work_struct      task_cleanup;
 225         struct timer_list       timer;
 226         unsigned long           last_used,
 227                                 idle_timeout,
 228                                 connect_timeout,
 229                                 max_reconnect_timeout;
 230
 231         /*
 232          * Send stuff
 233          */
 234         spinlock_t              transport_lock; /* lock transport info */
 235         spinlock_t              reserve_lock;   /* lock slot table */
 236         spinlock_t              recv_lock;      /* lock receive list */
 237         u32                     xid;            /* Next XID value to use */
 238         struct rpc_task *       snd_task;       /* Task blocked in send */
 239         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 240 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 241         struct svc_serv         *bc_serv;       /* The RPC service which will */
 242                                                 /* process the callback */
 243         int                     bc_alloc_count; /* Total number of preallocs */
 244         atomic_t                bc_free_slots;
 245         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 246                                                  * items */
 247         struct list_head        bc_pa_list;     /* List of preallocated
 248                                                  * backchannel rpc_rqst's */
 249 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 250         struct list_head        recv;
 251
 252         struct {
 253                 unsigned long           bind_count,     /* total number of binds */
 254                                         connect_count,  /* total number of connects */
 255                                         connect_start,  /* connect start timestamp */
 256                                         connect_time,   /* jiffies waiting for connect */
 257                                         sends,          /* how many complete requests */
 258                                         recvs,          /* how many complete requests */
 259                                         bad_xids,       /* lookup_rqst didn't find XID */
 260                                         max_slots;      /* max rpc_slots used */
 261
 262                 unsigned long long      req_u,          /* average requests on the wire */
 263                                         bklog_u,        /* backlog queue utilization */
 264                                         sending_u,      /* send q utilization */
 265                                         pending_u;      /* pend q utilization */
 266         } stat;
 267
 268         struct net              *xprt_net;
 269         const char              *servername;
 270         const char              *address_strings[RPC_DISPLAY_MAX];
 271 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 272         struct dentry           *debugfs;               /* debugfs directory */
 273         atomic_t                inject_disconnect;
 274 #endif
 275         struct rcu_head         rcu;
 276 };
 277
 278 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 279 /*
 280  * Backchannel flags
 281  */
 282 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 283                                                 /* buffer in use */
 284 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 285
 286 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 287 static inline int bc_prealloc(struct rpc_rqst *req)
 288 {
 289         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 290 }
 291 #else
 292 static inline int bc_prealloc(struct rpc_rqst *req)
 293 {
 294         return 0;
 295 }
 296 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 297
 298 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 299 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 300
 301 struct xprt_create {
 302         int                     ident;          /* XPRT_TRANSPORT identifier */
 303         struct net *            net;
 304         struct sockaddr *       srcaddr;        /* optional local address */
 305         struct sockaddr *       dstaddr;        /* remote peer address */
 306         size_t                  addrlen;
 307         const char              *servername;
 308         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 309         struct rpc_xprt_switch  *bc_xps;
 310         unsigned int            flags;
 311 };
 312
 313 struct xprt_class {
 314         struct list_head        list;
 315         int                     ident;          /* XPRT_TRANSPORT identifier */
 316         struct rpc_xprt *       (*setup)(struct xprt_create *);
 317         struct module           *owner;
 318         char                    name[32];
 319         const char *            netid[];
 320 };
 321
 322 /*
 323  * Generic internal transport functions
 324  */
 325 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 326 void                    xprt_connect(struct rpc_task *task);
 327 void                    xprt_reserve(struct rpc_task *task);
 328 void                    xprt_retry_reserve(struct rpc_task *task);
 329 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 330 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 331 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 332 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 333 bool                    xprt_prepare_transmit(struct rpc_task *task);
 334 void                    xprt_transmit(struct rpc_task *task);
 335 void                    xprt_end_transmit(struct rpc_task *task);
 336 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 337 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 338 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 339 void                    xprt_release(struct rpc_task *task);
 340 struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 341 void                    xprt_put(struct rpc_xprt *xprt);
 342 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 343                                 unsigned int num_prealloc,
 344                                 unsigned int max_req);
 345 void                    xprt_free(struct rpc_xprt *);
 346
 347 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 348 {
 349         return p + xprt->tsh_size;
 350 }
 351
 352 static inline int
 353 xprt_enable_swap(struct rpc_xprt *xprt)
 354 {
 355         return xprt->ops->enable_swap(xprt);
 356 }
 357
 358 static inline void
 359 xprt_disable_swap(struct rpc_xprt *xprt)
 360 {
 361         xprt->ops->disable_swap(xprt);
 362 }
 363
 364 /*
 365  * Transport switch helper functions
 366  */
 367 int                     xprt_register_transport(struct xprt_class *type);
 368 int                     xprt_unregister_transport(struct xprt_class *type);
 369 int                     xprt_load_transport(const char *);
 370 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 371 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 372 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 373 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 374 void                    xprt_write_space(struct rpc_xprt *xprt);
 375 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 376 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 377 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 378 void                    xprt_pin_rqst(struct rpc_rqst *req);
 379 void                    xprt_unpin_rqst(struct rpc_rqst *req);
 380 void                    xprt_release_rqst_cong(struct rpc_task *task);
 381 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 382 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 383 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 384
 385 bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 386 void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 387
 388 /*
 389  * Reserved bit positions in xprt->state
 390  */
 391 #define XPRT_LOCKED             (0)
 392 #define XPRT_CONNECTED          (1)
 393 #define XPRT_CONNECTING         (2)
 394 #define XPRT_CLOSE_WAIT         (3)
 395 #define XPRT_BOUND              (4)
 396 #define XPRT_BINDING            (5)
 397 #define XPRT_CLOSING            (6)
 398 #define XPRT_CONGESTED          (9)
 399
 400 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 401 {
 402         set_bit(XPRT_CONNECTED, &xprt->state);
 403 }
 404
 405 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 406 {
 407         clear_bit(XPRT_CONNECTED, &xprt->state);
 408 }
 409
 410 static inline int xprt_connected(struct rpc_xprt *xprt)
 411 {
 412         return test_bit(XPRT_CONNECTED, &xprt->state);
 413 }
 414
 415 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 416 {
 417         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 418 }
 419
 420 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 421 {
 422         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 423 }
 424
 425 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 426 {
 427         smp_mb__before_atomic();
 428         clear_bit(XPRT_CONNECTING, &xprt->state);
 429         smp_mb__after_atomic();
 430 }
 431
 432 static inline int xprt_connecting(struct rpc_xprt *xprt)
 433 {
 434         return test_bit(XPRT_CONNECTING, &xprt->state);
 435 }
 436
 437 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 438 {
 439         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 440 }
 441
 442 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 443 {
 444         test_and_set_bit(XPRT_BOUND, &xprt->state);
 445 }
 446
 447 static inline int xprt_bound(struct rpc_xprt *xprt)
 448 {
 449         return test_bit(XPRT_BOUND, &xprt->state);
 450 }
 451
 452 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 453 {
 454         clear_bit(XPRT_BOUND, &xprt->state);
 455 }
 456
 457 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 458 {
 459         smp_mb__before_atomic();
 460         clear_bit(XPRT_BINDING, &xprt->state);
 461         smp_mb__after_atomic();
 462 }
 463
 464 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 465 {
 466         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 467 }
 468
 469 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 470 extern unsigned int rpc_inject_disconnect;
 471 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 472 {
 473         if (!rpc_inject_disconnect)
 474                 return;
 475         if (atomic_dec_return(&xprt->inject_disconnect))
 476                 return;
 477         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 478         xprt->ops->inject_disconnect(xprt);
 479 }
 480 #else
 481 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 482 {
 483 }
 484 #endif
 485
 486 #endif /* __KERNEL__*/
 487
 488 #endif /* _LINUX_SUNRPC_XPRT_H */