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 };
 137
 138 /*
 139  * RPC transport identifiers
 140  *
 141  * To preserve compatibility with the historical use of raw IP protocol
 142  * id's for transport selection, UDP and TCP identifiers are specified
 143  * with the previous values. No such restriction exists for new transports,
 144  * except that they may not collide with these values (17 and 6,
 145  * respectively).
 146  */
 147 #define XPRT_TRANSPORT_BC       (1 << 31)
 148 enum xprt_transports {
 149         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 150         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 151         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 152         XPRT_TRANSPORT_RDMA     = 256,
 153         XPRT_TRANSPORT_LOCAL    = 257,
 154 };
 155
 156 struct rpc_xprt {
 157         atomic_t                count;          /* Reference count */
 158         struct rpc_xprt_ops *   ops;            /* transport methods */
 159
 160         const struct rpc_timeout *timeout;      /* timeout parms */
 161         struct sockaddr_storage addr;           /* server address */
 162         size_t                  addrlen;        /* size of server address */
 163         int                     prot;           /* IP protocol */
 164
 165         unsigned long           cong;           /* current congestion */
 166         unsigned long           cwnd;           /* congestion window */
 167
 168         size_t                  max_payload;    /* largest RPC payload size,
 169                                                    in bytes */
 170         unsigned int            tsh_size;       /* size of transport specific
 171                                                    header */
 172
 173         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 174         struct rpc_wait_queue   sending;        /* requests waiting to send */
 175         struct rpc_wait_queue   pending;        /* requests in flight */
 176         struct rpc_wait_queue   backlog;        /* waiting for slot */
 177         struct list_head        free;           /* free slots */
 178         unsigned int            max_reqs;       /* max number of slots */
 179         unsigned int            min_reqs;       /* min number of slots */
 180         atomic_t                num_reqs;       /* total slots */
 181         unsigned long           state;          /* transport state */
 182         unsigned char           resvport   : 1; /* use a reserved port */
 183         unsigned int            swapper;        /* we're swapping over this
 184                                                    transport */
 185         unsigned int            bind_index;     /* bind function index */
 186
 187         /*
 188          * Connection of transports
 189          */
 190         unsigned long           bind_timeout,
 191                                 reestablish_timeout;
 192         unsigned int            connect_cookie; /* A cookie that gets bumped
 193                                                    every time the transport
 194                                                    is reconnected */
 195
 196         /*
 197          * Disconnection of idle transports
 198          */
 199         struct work_struct      task_cleanup;
 200         struct timer_list       timer;
 201         unsigned long           last_used,
 202                                 idle_timeout;
 203
 204         /*
 205          * Send stuff
 206          */
 207         spinlock_t              transport_lock; /* lock transport info */
 208         spinlock_t              reserve_lock;   /* lock slot table */
 209         u32                     xid;            /* Next XID value to use */
 210         struct rpc_task *       snd_task;       /* Task blocked in send */
 211         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 212 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 213         struct svc_serv         *bc_serv;       /* The RPC service which will */
 214                                                 /* process the callback */
 215         unsigned int            bc_alloc_count; /* Total number of preallocs */
 216         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 217                                                  * items */
 218         struct list_head        bc_pa_list;     /* List of preallocated
 219                                                  * backchannel rpc_rqst's */
 220 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 221         struct list_head        recv;
 222
 223         struct {
 224                 unsigned long           bind_count,     /* total number of binds */
 225                                         connect_count,  /* total number of connects */
 226                                         connect_start,  /* connect start timestamp */
 227                                         connect_time,   /* jiffies waiting for connect */
 228                                         sends,          /* how many complete requests */
 229                                         recvs,          /* how many complete requests */
 230                                         bad_xids,       /* lookup_rqst didn't find XID */
 231                                         max_slots;      /* max rpc_slots used */
 232
 233                 unsigned long long      req_u,          /* average requests on the wire */
 234                                         bklog_u,        /* backlog queue utilization */
 235                                         sending_u,      /* send q utilization */
 236                                         pending_u;      /* pend q utilization */
 237         } stat;
 238
 239         struct net              *xprt_net;
 240         const char              *servername;
 241         const char              *address_strings[RPC_DISPLAY_MAX];
 242 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 243         struct dentry           *debugfs;               /* debugfs directory */
 244 #endif
 245 };
 246
 247 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 248 /*
 249  * Backchannel flags
 250  */
 251 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 252                                                 /* buffer in use */
 253 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 254
 255 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 256 static inline int bc_prealloc(struct rpc_rqst *req)
 257 {
 258         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 259 }
 260 #else
 261 static inline int bc_prealloc(struct rpc_rqst *req)
 262 {
 263         return 0;
 264 }
 265 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 266
 267 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 268 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 269
 270 struct xprt_create {
 271         int                     ident;          /* XPRT_TRANSPORT identifier */
 272         struct net *            net;
 273         struct sockaddr *       srcaddr;        /* optional local address */
 274         struct sockaddr *       dstaddr;        /* remote peer address */
 275         size_t                  addrlen;
 276         const char              *servername;
 277         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 278         unsigned int            flags;
 279 };
 280
 281 struct xprt_class {
 282         struct list_head        list;
 283         int                     ident;          /* XPRT_TRANSPORT identifier */
 284         struct rpc_xprt *       (*setup)(struct xprt_create *);
 285         struct module           *owner;
 286         char                    name[32];
 287 };
 288
 289 /*
 290  * Generic internal transport functions
 291  */
 292 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 293 void                    xprt_connect(struct rpc_task *task);
 294 void                    xprt_reserve(struct rpc_task *task);
 295 void                    xprt_retry_reserve(struct rpc_task *task);
 296 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 297 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 298 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 299 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 300 bool                    xprt_prepare_transmit(struct rpc_task *task);
 301 void                    xprt_transmit(struct rpc_task *task);
 302 void                    xprt_end_transmit(struct rpc_task *task);
 303 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 304 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 305 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 306 void                    xprt_release(struct rpc_task *task);
 307 void                    xprt_put(struct rpc_xprt *xprt);
 308 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 309                                 unsigned int num_prealloc,
 310                                 unsigned int max_req);
 311 void                    xprt_free(struct rpc_xprt *);
 312
 313 /**
 314  * xprt_get - return a reference to an RPC transport.
 315  * @xprt: pointer to the transport
 316  *
 317  */
 318 static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
 319 {
 320         if (atomic_inc_not_zero(&xprt->count))
 321                 return xprt;
 322         return NULL;
 323 }
 324
 325 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 326 {
 327         return p + xprt->tsh_size;
 328 }
 329
 330 /*
 331  * Transport switch helper functions
 332  */
 333 int                     xprt_register_transport(struct xprt_class *type);
 334 int                     xprt_unregister_transport(struct xprt_class *type);
 335 int                     xprt_load_transport(const char *);
 336 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 337 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 338 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 339 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 340 void                    xprt_write_space(struct rpc_xprt *xprt);
 341 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 342 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 343 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 344 void                    xprt_release_rqst_cong(struct rpc_task *task);
 345 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 346 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 347 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 348 int                     xs_swapper(struct rpc_xprt *xprt, int enable);
 349
 350 bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 351 void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 352
 353 /*
 354  * Reserved bit positions in xprt->state
 355  */
 356 #define XPRT_LOCKED             (0)
 357 #define XPRT_CONNECTED          (1)
 358 #define XPRT_CONNECTING         (2)
 359 #define XPRT_CLOSE_WAIT         (3)
 360 #define XPRT_BOUND              (4)
 361 #define XPRT_BINDING            (5)
 362 #define XPRT_CLOSING            (6)
 363 #define XPRT_CONGESTED          (9)
 364
 365 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 366 {
 367         set_bit(XPRT_CONNECTED, &xprt->state);
 368 }
 369
 370 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 371 {
 372         clear_bit(XPRT_CONNECTED, &xprt->state);
 373 }
 374
 375 static inline int xprt_connected(struct rpc_xprt *xprt)
 376 {
 377         return test_bit(XPRT_CONNECTED, &xprt->state);
 378 }
 379
 380 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 381 {
 382         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 383 }
 384
 385 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 386 {
 387         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 388 }
 389
 390 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 391 {
 392         smp_mb__before_atomic();
 393         clear_bit(XPRT_CONNECTING, &xprt->state);
 394         smp_mb__after_atomic();
 395 }
 396
 397 static inline int xprt_connecting(struct rpc_xprt *xprt)
 398 {
 399         return test_bit(XPRT_CONNECTING, &xprt->state);
 400 }
 401
 402 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 403 {
 404         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 405 }
 406
 407 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 408 {
 409         test_and_set_bit(XPRT_BOUND, &xprt->state);
 410 }
 411
 412 static inline int xprt_bound(struct rpc_xprt *xprt)
 413 {
 414         return test_bit(XPRT_BOUND, &xprt->state);
 415 }
 416
 417 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 418 {
 419         clear_bit(XPRT_BOUND, &xprt->state);
 420 }
 421
 422 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 423 {
 424         smp_mb__before_atomic();
 425         clear_bit(XPRT_BINDING, &xprt->state);
 426         smp_mb__after_atomic();
 427 }
 428
 429 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 430 {
 431         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 432 }
 433
 434 #endif /* __KERNEL__*/
 435
 436 #endif /* _LINUX_SUNRPC_XPRT_H */