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