kernel/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/sunrpc/sched.h>
  17 #include <linux/sunrpc/xdr.h>
  18 #include <linux/sunrpc/msg_prot.h>
  19
  20 #ifdef __KERNEL__
  21
  22 #define RPC_MIN_SLOT_TABLE      (2U)
  23 #define RPC_DEF_SLOT_TABLE      (16U)
  24 #define RPC_MAX_SLOT_TABLE_LIMIT        (65536U)
  25 #define RPC_MAX_SLOT_TABLE      RPC_MAX_SLOT_TABLE_LIMIT
  26
  27 #define RPC_CWNDSHIFT           (8U)
  28 #define RPC_CWNDSCALE           (1U << RPC_CWNDSHIFT)
  29 #define RPC_INITCWND            RPC_CWNDSCALE
  30 #define RPC_MAXCWND(xprt)       ((xprt)->max_reqs << RPC_CWNDSHIFT)
  31 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
  32
  33 /*
  34  * This describes a timeout strategy
  35  */
  36 struct rpc_timeout {
  37         unsigned long           to_initval,             /* initial timeout */
  38                                 to_maxval,              /* max timeout */
  39                                 to_increment;           /* if !exponential */
  40         unsigned int            to_retries;             /* max # of retries */
  41         unsigned char           to_exponential;
  42 };
  43
  44 enum rpc_display_format_t {
  45         RPC_DISPLAY_ADDR = 0,
  46         RPC_DISPLAY_PORT,
  47         RPC_DISPLAY_PROTO,
  48         RPC_DISPLAY_HEX_ADDR,
  49         RPC_DISPLAY_HEX_PORT,
  50         RPC_DISPLAY_NETID,
  51         RPC_DISPLAY_MAX,
  52 };
  53
  54 struct rpc_task;
  55 struct rpc_xprt;
  56 struct seq_file;
  57 struct svc_serv;
  58 struct net;
  59
  60 /*
  61  * This describes a complete RPC request
  62  */
  63 struct rpc_rqst {
  64         /*
  65          * This is the user-visible part
  66          */
  67         struct rpc_xprt *       rq_xprt;                /* RPC client */
  68         struct xdr_buf          rq_snd_buf;             /* send buffer */
  69         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  70
  71         /*
  72          * This is the private part
  73          */
  74         struct rpc_task *       rq_task;        /* RPC task data */
  75         struct rpc_cred *       rq_cred;        /* Bound cred */
  76         __be32                  rq_xid;         /* request XID */
  77         int                     rq_cong;        /* has incremented xprt->cong */
  78         u32                     rq_seqno;       /* gss seq no. used on req. */
  79         int                     rq_enc_pages_num;
  80         struct page             **rq_enc_pages; /* scratch pages for use by
  81                                                    gss privacy code */
  82         void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  83         struct list_head        rq_list;
  84
  85         __u32 *                 rq_buffer;      /* XDR encode buffer */
  86         size_t                  rq_callsize,
  87                                 rq_rcvsize;
  88         size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  89         size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  90                                                         /* received */
  91
  92         struct xdr_buf          rq_private_buf;         /* The receive buffer
  93                                                          * used in the softirq.
  94                                                          */
  95         unsigned long           rq_majortimeo;  /* major timeout alarm */
  96         unsigned long           rq_timeout;     /* Current timeout value */
  97         ktime_t                 rq_rtt;         /* round-trip time */
  98         unsigned int            rq_retries;     /* # of retries */
  99         unsigned int            rq_connect_cookie;
 100                                                 /* A cookie used to track the
 101                                                    state of the transport
 102                                                    connection */
 103
 104         /*
 105          * Partial send handling
 106          */
 107         u32                     rq_bytes_sent;  /* Bytes we have sent */
 108
 109         ktime_t                 rq_xtime;       /* transmit time stamp */
 110         int                     rq_ntrans;
 111
 112 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 113         struct list_head        rq_bc_list;     /* Callback service list */
 114         unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 115         struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 116 #endif /* CONFIG_SUNRPC_BACKCHANEL */
 117 };
 118 #define rq_svec                 rq_snd_buf.head
 119 #define rq_slen                 rq_snd_buf.len
 120
 121 struct rpc_xprt_ops {
 122         void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 123         int             (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 124         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 125         void            (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
 126         void            (*rpcbind)(struct rpc_task *task);
 127         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 128         void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 129         void *          (*buf_alloc)(struct rpc_task *task, size_t size);
 130         void            (*buf_free)(void *buffer);
 131         int             (*send_request)(struct rpc_task *task);
 132         void            (*set_retrans_timeout)(struct rpc_task *task);
 133         void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 134         void            (*release_request)(struct rpc_task *task);
 135         void            (*close)(struct rpc_xprt *xprt);
 136         void            (*destroy)(struct rpc_xprt *xprt);
 137         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 138         int             (*enable_swap)(struct rpc_xprt *xprt);
 139         void            (*disable_swap)(struct rpc_xprt *xprt);
 140         void            (*inject_disconnect)(struct rpc_xprt *xprt);
 141         int             (*bc_setup)(struct rpc_xprt *xprt,
 142                                     unsigned int min_reqs);
 143         int             (*bc_up)(struct svc_serv *serv, struct net *net);
 144         void            (*bc_free_rqst)(struct rpc_rqst *rqst);
 145         void            (*bc_destroy)(struct rpc_xprt *xprt,
 146                                       unsigned int max_reqs);
 147 };
 148
 149 /*
 150  * RPC transport identifiers
 151  *
 152  * To preserve compatibility with the historical use of raw IP protocol
 153  * id's for transport selection, UDP and TCP identifiers are specified
 154  * with the previous values. No such restriction exists for new transports,
 155  * except that they may not collide with these values (17 and 6,
 156  * respectively).
 157  */
 158 #define XPRT_TRANSPORT_BC       (1 << 31)
 159 enum xprt_transports {
 160         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 161         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 162         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 163         XPRT_TRANSPORT_RDMA     = 256,
 164         XPRT_TRANSPORT_BC_RDMA  = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
 165         XPRT_TRANSPORT_LOCAL    = 257,
 166 };
 167
 168 struct rpc_xprt {
 169         atomic_t                count;          /* Reference count */
 170         struct rpc_xprt_ops *   ops;            /* transport methods */
 171
 172         const struct rpc_timeout *timeout;      /* timeout parms */
 173         struct sockaddr_storage addr;           /* server address */
 174         size_t                  addrlen;        /* size of server address */
 175         int                     prot;           /* IP protocol */
 176
 177         unsigned long           cong;           /* current congestion */
 178         unsigned long           cwnd;           /* congestion window */
 179
 180         size_t                  max_payload;    /* largest RPC payload size,
 181                                                    in bytes */
 182         unsigned int            tsh_size;       /* size of transport specific
 183                                                    header */
 184
 185         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 186         struct rpc_wait_queue   sending;        /* requests waiting to send */
 187         struct rpc_wait_queue   pending;        /* requests in flight */
 188         struct rpc_wait_queue   backlog;        /* waiting for slot */
 189         struct list_head        free;           /* free slots */
 190         unsigned int            max_reqs;       /* max number of slots */
 191         unsigned int            min_reqs;       /* min number of slots */
 192         atomic_t                num_reqs;       /* total slots */
 193         unsigned long           state;          /* transport state */
 194         unsigned char           resvport   : 1; /* use a reserved port */
 195         atomic_t                swapper;        /* we're swapping over this
 196                                                    transport */
 197         unsigned int            bind_index;     /* bind function index */
 198
 199         /*
 200          * Connection of transports
 201          */
 202         unsigned long           bind_timeout,
 203                                 reestablish_timeout;
 204         unsigned int            connect_cookie; /* A cookie that gets bumped
 205                                                    every time the transport
 206                                                    is reconnected */
 207
 208         /*
 209          * Disconnection of idle transports
 210          */
 211         struct work_struct      task_cleanup;
 212         struct timer_list       timer;
 213         unsigned long           last_used,
 214                                 idle_timeout;
 215
 216         /*
 217          * Send stuff
 218          */
 219         spinlock_t              transport_lock; /* lock transport info */
 220         spinlock_t              reserve_lock;   /* lock slot table */
 221         u32                     xid;            /* Next XID value to use */
 222         struct rpc_task *       snd_task;       /* Task blocked in send */
 223         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 224 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 225         struct svc_serv         *bc_serv;       /* The RPC service which will */
 226                                                 /* process the callback */
 227         int                     bc_alloc_count; /* Total number of preallocs */
 228         atomic_t                bc_free_slots;
 229         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 230                                                  * items */
 231         struct list_head        bc_pa_list;     /* List of preallocated
 232                                                  * backchannel rpc_rqst's */
 233 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 234         struct list_head        recv;
 235
 236         struct {
 237                 unsigned long           bind_count,     /* total number of binds */
 238                                         connect_count,  /* total number of connects */
 239                                         connect_start,  /* connect start timestamp */
 240                                         connect_time,   /* jiffies waiting for connect */
 241                                         sends,          /* how many complete requests */
 242                                         recvs,          /* how many complete requests */
 243                                         bad_xids,       /* lookup_rqst didn't find XID */
 244                                         max_slots;      /* max rpc_slots used */
 245
 246                 unsigned long long      req_u,          /* average requests on the wire */
 247                                         bklog_u,        /* backlog queue utilization */
 248                                         sending_u,      /* send q utilization */
 249                                         pending_u;      /* pend q utilization */
 250         } stat;
 251
 252         struct net              *xprt_net;
 253         const char              *servername;
 254         const char              *address_strings[RPC_DISPLAY_MAX];
 255 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 256         struct dentry           *debugfs;               /* debugfs directory */
 257         atomic_t                inject_disconnect;
 258 #endif
 259 };
 260
 261 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 262 /*
 263  * Backchannel flags
 264  */
 265 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 266                                                 /* buffer in use */
 267 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 268
 269 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 270 static inline int bc_prealloc(struct rpc_rqst *req)
 271 {
 272         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 273 }
 274 #else
 275 static inline int bc_prealloc(struct rpc_rqst *req)
 276 {
 277         return 0;
 278 }
 279 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 280
 281 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 282 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 283
 284 struct xprt_create {
 285         int                     ident;          /* XPRT_TRANSPORT identifier */
 286         struct net *            net;
 287         struct sockaddr *       srcaddr;        /* optional local address */
 288         struct sockaddr *       dstaddr;        /* remote peer address */
 289         size_t                  addrlen;
 290         const char              *servername;
 291         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 292         unsigned int            flags;
 293 };
 294
 295 struct xprt_class {
 296         struct list_head        list;
 297         int                     ident;          /* XPRT_TRANSPORT identifier */
 298         struct rpc_xprt *       (*setup)(struct xprt_create *);
 299         struct module           *owner;
 300         char                    name[32];
 301 };
 302
 303 /*
 304  * Generic internal transport functions
 305  */
 306 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 307 void                    xprt_connect(struct rpc_task *task);
 308 void                    xprt_reserve(struct rpc_task *task);
 309 void                    xprt_retry_reserve(struct rpc_task *task);
 310 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 311 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 312 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 313 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 314 bool                    xprt_prepare_transmit(struct rpc_task *task);
 315 void                    xprt_transmit(struct rpc_task *task);
 316 void                    xprt_end_transmit(struct rpc_task *task);
 317 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 318 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 319 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 320 void                    xprt_release(struct rpc_task *task);
 321 void                    xprt_put(struct rpc_xprt *xprt);
 322 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 323                                 unsigned int num_prealloc,
 324                                 unsigned int max_req);
 325 void                    xprt_free(struct rpc_xprt *);
 326
 327 /**
 328  * xprt_get - return a reference to an RPC transport.
 329  * @xprt: pointer to the transport
 330  *
 331  */
 332 static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
 333 {
 334         if (atomic_inc_not_zero(&xprt->count))
 335                 return xprt;
 336         return NULL;
 337 }
 338
 339 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 340 {
 341         return p + xprt->tsh_size;
 342 }
 343
 344 static inline int
 345 xprt_enable_swap(struct rpc_xprt *xprt)
 346 {
 347         return xprt->ops->enable_swap(xprt);
 348 }
 349
 350 static inline void
 351 xprt_disable_swap(struct rpc_xprt *xprt)
 352 {
 353         xprt->ops->disable_swap(xprt);
 354 }
 355
 356 /*
 357  * Transport switch helper functions
 358  */
 359 int                     xprt_register_transport(struct xprt_class *type);
 360 int                     xprt_unregister_transport(struct xprt_class *type);
 361 int                     xprt_load_transport(const char *);
 362 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 363 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 364 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 365 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 366 void                    xprt_write_space(struct rpc_xprt *xprt);
 367 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 368 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 369 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 370 void                    xprt_release_rqst_cong(struct rpc_task *task);
 371 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 372 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 373 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 374
 375 bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 376 void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 377
 378 /*
 379  * Reserved bit positions in xprt->state
 380  */
 381 #define XPRT_LOCKED             (0)
 382 #define XPRT_CONNECTED          (1)
 383 #define XPRT_CONNECTING         (2)
 384 #define XPRT_CLOSE_WAIT         (3)
 385 #define XPRT_BOUND              (4)
 386 #define XPRT_BINDING            (5)
 387 #define XPRT_CLOSING            (6)
 388 #define XPRT_CONGESTED          (9)
 389
 390 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 391 {
 392         set_bit(XPRT_CONNECTED, &xprt->state);
 393 }
 394
 395 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 396 {
 397         clear_bit(XPRT_CONNECTED, &xprt->state);
 398 }
 399
 400 static inline int xprt_connected(struct rpc_xprt *xprt)
 401 {
 402         return test_bit(XPRT_CONNECTED, &xprt->state);
 403 }
 404
 405 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 406 {
 407         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 408 }
 409
 410 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 411 {
 412         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 413 }
 414
 415 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 416 {
 417         smp_mb__before_atomic();
 418         clear_bit(XPRT_CONNECTING, &xprt->state);
 419         smp_mb__after_atomic();
 420 }
 421
 422 static inline int xprt_connecting(struct rpc_xprt *xprt)
 423 {
 424         return test_bit(XPRT_CONNECTING, &xprt->state);
 425 }
 426
 427 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 428 {
 429         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 430 }
 431
 432 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 433 {
 434         test_and_set_bit(XPRT_BOUND, &xprt->state);
 435 }
 436
 437 static inline int xprt_bound(struct rpc_xprt *xprt)
 438 {
 439         return test_bit(XPRT_BOUND, &xprt->state);
 440 }
 441
 442 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 443 {
 444         clear_bit(XPRT_BOUND, &xprt->state);
 445 }
 446
 447 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 448 {
 449         smp_mb__before_atomic();
 450         clear_bit(XPRT_BINDING, &xprt->state);
 451         smp_mb__after_atomic();
 452 }
 453
 454 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 455 {
 456         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 457 }
 458
 459 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 460 extern unsigned int rpc_inject_disconnect;
 461 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 462 {
 463         if (!rpc_inject_disconnect)
 464                 return;
 465         if (atomic_dec_return(&xprt->inject_disconnect))
 466                 return;
 467         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 468         xprt->ops->inject_disconnect(xprt);
 469 }
 470 #else
 471 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 472 {
 473 }
 474 #endif
 475
 476 #endif /* __KERNEL__*/
 477
 478 #endif /* _LINUX_SUNRPC_XPRT_H */