LXR linux/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#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 */
  36struct 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
  44enum 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
  54struct rpc_task;
  55struct rpc_xprt;
  56struct xprt_class;
  57struct seq_file;
  58struct svc_serv;
  59struct net;
  60
  61/*
  62 * This describes a complete RPC request
  63 */
  64struct 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
  85        union {
  86                struct list_head        rq_list;        /* Slot allocation list */
  87                struct rb_node          rq_recv;        /* Receive queue */
  88        };
  89
  90        struct list_head        rq_xmit;        /* Send queue */
  91        struct list_head        rq_xmit2;       /* Send queue */
  92
  93        void                    *rq_buffer;     /* Call XDR encode buffer */
  94        size_t                  rq_callsize;
  95        void                    *rq_rbuffer;    /* Reply XDR decode buffer */
  96        size_t                  rq_rcvsize;
  97        size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  98        size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  99                                                        /* received */
 100
 101        struct xdr_buf          rq_private_buf;         /* The receive buffer
 102                                                         * used in the softirq.
 103                                                         */
 104        unsigned long           rq_majortimeo;  /* major timeout alarm */
 105        unsigned long           rq_minortimeo;  /* minor timeout alarm */
 106        unsigned long           rq_timeout;     /* Current timeout value */
 107        ktime_t                 rq_rtt;         /* round-trip time */
 108        unsigned int            rq_retries;     /* # of retries */
 109        unsigned int            rq_connect_cookie;
 110                                                /* A cookie used to track the
 111                                                   state of the transport
 112                                                   connection */
 113        atomic_t                rq_pin;
 114        
 115        /*
 116         * Partial send handling
 117         */
 118        u32                     rq_bytes_sent;  /* Bytes we have sent */
 119
 120        ktime_t                 rq_xtime;       /* transmit time stamp */
 121        int                     rq_ntrans;
 122
 123#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 124        struct list_head        rq_bc_list;     /* Callback service list */
 125        unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 126        struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 127#endif /* CONFIG_SUNRPC_BACKCHANEL */
 128};
 129#define rq_svec                 rq_snd_buf.head
 130#define rq_slen                 rq_snd_buf.len
 131
 132struct rpc_xprt_ops {
 133        void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 134        int             (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 135        void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 136        void            (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
 137        void            (*free_slot)(struct rpc_xprt *xprt,
 138                                     struct rpc_rqst *req);
 139        void            (*rpcbind)(struct rpc_task *task);
 140        void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 141        void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 142        int             (*buf_alloc)(struct rpc_task *task);
 143        void            (*buf_free)(struct rpc_task *task);
 144        void            (*prepare_request)(struct rpc_rqst *req);
 145        int             (*send_request)(struct rpc_rqst *req);
 146        void            (*wait_for_reply_request)(struct rpc_task *task);
 147        void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 148        void            (*release_request)(struct rpc_task *task);
 149        void            (*close)(struct rpc_xprt *xprt);
 150        void            (*destroy)(struct rpc_xprt *xprt);
 151        void            (*set_connect_timeout)(struct rpc_xprt *xprt,
 152                                        unsigned long connect_timeout,
 153                                        unsigned long reconnect_timeout);
 154        void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 155        int             (*enable_swap)(struct rpc_xprt *xprt);
 156        void            (*disable_swap)(struct rpc_xprt *xprt);
 157        void            (*inject_disconnect)(struct rpc_xprt *xprt);
 158        int             (*bc_setup)(struct rpc_xprt *xprt,
 159                                    unsigned int min_reqs);
 160        size_t          (*bc_maxpayload)(struct rpc_xprt *xprt);
 161        unsigned int    (*bc_num_slots)(struct rpc_xprt *xprt);
 162        void            (*bc_free_rqst)(struct rpc_rqst *rqst);
 163        void            (*bc_destroy)(struct rpc_xprt *xprt,
 164                                      unsigned int max_reqs);
 165};
 166
 167/*
 168 * RPC transport identifiers
 169 *
 170 * To preserve compatibility with the historical use of raw IP protocol
 171 * id's for transport selection, UDP and TCP identifiers are specified
 172 * with the previous values. No such restriction exists for new transports,
 173 * except that they may not collide with these values (17 and 6,
 174 * respectively).
 175 */
 176#define XPRT_TRANSPORT_BC       (1 << 31)
 177enum xprt_transports {
 178        XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 179        XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 180        XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 181        XPRT_TRANSPORT_RDMA     = 256,
 182        XPRT_TRANSPORT_BC_RDMA  = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
 183        XPRT_TRANSPORT_LOCAL    = 257,
 184};
 185
 186struct rpc_sysfs_xprt;
 187struct rpc_xprt {
 188        struct kref             kref;           /* Reference count */
 189        const struct rpc_xprt_ops *ops;         /* transport methods */
 190        unsigned int            id;             /* transport id */
 191
 192        const struct rpc_timeout *timeout;      /* timeout parms */
 193        struct sockaddr_storage addr;           /* server address */
 194        size_t                  addrlen;        /* size of server address */
 195        int                     prot;           /* IP protocol */
 196
 197        unsigned long           cong;           /* current congestion */
 198        unsigned long           cwnd;           /* congestion window */
 199
 200        size_t                  max_payload;    /* largest RPC payload size,
 201                                                   in bytes */
 202
 203        struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 204        struct rpc_wait_queue   sending;        /* requests waiting to send */
 205        struct rpc_wait_queue   pending;        /* requests in flight */
 206        struct rpc_wait_queue   backlog;        /* waiting for slot */
 207        struct list_head        free;           /* free slots */
 208        unsigned int            max_reqs;       /* max number of slots */
 209        unsigned int            min_reqs;       /* min number of slots */
 210        unsigned int            num_reqs;       /* total slots */
 211        unsigned long           state;          /* transport state */
 212        unsigned char           resvport   : 1, /* use a reserved port */
 213                                reuseport  : 1; /* reuse port on reconnect */
 214        atomic_t                swapper;        /* we're swapping over this
 215                                                   transport */
 216        unsigned int            bind_index;     /* bind function index */
 217
 218        /*
 219         * Multipath
 220         */
 221        struct list_head        xprt_switch;
 222
 223        /*
 224         * Connection of transports
 225         */
 226        unsigned long           bind_timeout,
 227                                reestablish_timeout;
 228        unsigned int            connect_cookie; /* A cookie that gets bumped
 229                                                   every time the transport
 230                                                   is reconnected */
 231
 232        /*
 233         * Disconnection of idle transports
 234         */
 235        struct work_struct      task_cleanup;
 236        struct timer_list       timer;
 237        unsigned long           last_used,
 238                                idle_timeout,
 239                                connect_timeout,
 240                                max_reconnect_timeout;
 241
 242        /*
 243         * Send stuff
 244         */
 245        atomic_long_t           queuelen;
 246        spinlock_t              transport_lock; /* lock transport info */
 247        spinlock_t              reserve_lock;   /* lock slot table */
 248        spinlock_t              queue_lock;     /* send/receive queue lock */
 249        u32                     xid;            /* Next XID value to use */
 250        struct rpc_task *       snd_task;       /* Task blocked in send */
 251
 252        struct list_head        xmit_queue;     /* Send queue */
 253        atomic_long_t           xmit_queuelen;
 254
 255        struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 256#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 257        struct svc_serv         *bc_serv;       /* The RPC service which will */
 258                                                /* process the callback */
 259        unsigned int            bc_alloc_max;
 260        unsigned int            bc_alloc_count; /* Total number of preallocs */
 261        atomic_t                bc_slot_count;  /* Number of allocated slots */
 262        spinlock_t              bc_pa_lock;     /* Protects the preallocated
 263                                                 * items */
 264        struct list_head        bc_pa_list;     /* List of preallocated
 265                                                 * backchannel rpc_rqst's */
 266#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 267
 268        struct rb_root          recv_queue;     /* Receive queue */
 269
 270        struct {
 271                unsigned long           bind_count,     /* total number of binds */
 272                                        connect_count,  /* total number of connects */
 273                                        connect_start,  /* connect start timestamp */
 274                                        connect_time,   /* jiffies waiting for connect */
 275                                        sends,          /* how many complete requests */
 276                                        recvs,          /* how many complete requests */
 277                                        bad_xids,       /* lookup_rqst didn't find XID */
 278                                        max_slots;      /* max rpc_slots used */
 279
 280                unsigned long long      req_u,          /* average requests on the wire */
 281                                        bklog_u,        /* backlog queue utilization */
 282                                        sending_u,      /* send q utilization */
 283                                        pending_u;      /* pend q utilization */
 284        } stat;
 285
 286        struct net              *xprt_net;
 287        const char              *servername;
 288        const char              *address_strings[RPC_DISPLAY_MAX];
 289#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 290        struct dentry           *debugfs;               /* debugfs directory */
 291#endif
 292        struct rcu_head         rcu;
 293        const struct xprt_class *xprt_class;
 294        struct rpc_sysfs_xprt   *xprt_sysfs;
 295        bool                    main; /*mark if this is the 1st transport */
 296};
 297
 298#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 299/*
 300 * Backchannel flags
 301 */
 302#define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 303                                                /* buffer in use */
 304#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 305
 306#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 307static inline int bc_prealloc(struct rpc_rqst *req)
 308{
 309        return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 310}
 311#else
 312static inline int bc_prealloc(struct rpc_rqst *req)
 313{
 314        return 0;
 315}
 316#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 317
 318#define XPRT_CREATE_INFINITE_SLOTS      (1U)
 319#define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 320
 321struct xprt_create {
 322        int                     ident;          /* XPRT_TRANSPORT identifier */
 323        struct net *            net;
 324        struct sockaddr *       srcaddr;        /* optional local address */
 325        struct sockaddr *       dstaddr;        /* remote peer address */
 326        size_t                  addrlen;
 327        const char              *servername;
 328        struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 329        struct rpc_xprt_switch  *bc_xps;
 330        unsigned int            flags;
 331};
 332
 333struct xprt_class {
 334        struct list_head        list;
 335        int                     ident;          /* XPRT_TRANSPORT identifier */
 336        struct rpc_xprt *       (*setup)(struct xprt_create *);
 337        struct module           *owner;
 338        char                    name[32];
 339        const char *            netid[];
 340};
 341
 342/*
 343 * Generic internal transport functions
 344 */
 345struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 346void                    xprt_connect(struct rpc_task *task);
 347unsigned long           xprt_reconnect_delay(const struct rpc_xprt *xprt);
 348void                    xprt_reconnect_backoff(struct rpc_xprt *xprt,
 349                                               unsigned long init_to);
 350void                    xprt_reserve(struct rpc_task *task);
 351void                    xprt_retry_reserve(struct rpc_task *task);
 352int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 353int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 354void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 355void                    xprt_free_slot(struct rpc_xprt *xprt,
 356                                       struct rpc_rqst *req);
 357void                    xprt_request_prepare(struct rpc_rqst *req);
 358bool                    xprt_prepare_transmit(struct rpc_task *task);
 359void                    xprt_request_enqueue_transmit(struct rpc_task *task);
 360void                    xprt_request_enqueue_receive(struct rpc_task *task);
 361void                    xprt_request_wait_receive(struct rpc_task *task);
 362void                    xprt_request_dequeue_xprt(struct rpc_task *task);
 363bool                    xprt_request_need_retransmit(struct rpc_task *task);
 364void                    xprt_transmit(struct rpc_task *task);
 365void                    xprt_end_transmit(struct rpc_task *task);
 366int                     xprt_adjust_timeout(struct rpc_rqst *req);
 367void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 368void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 369void                    xprt_release(struct rpc_task *task);
 370struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 371void                    xprt_put(struct rpc_xprt *xprt);
 372struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 373                                unsigned int num_prealloc,
 374                                unsigned int max_req);
 375void                    xprt_free(struct rpc_xprt *);
 376void                    xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task);
 377bool                    xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
 378void                    xprt_cleanup_ids(void);
 379
 380static inline int
 381xprt_enable_swap(struct rpc_xprt *xprt)
 382{
 383        return xprt->ops->enable_swap(xprt);
 384}
 385
 386static inline void
 387xprt_disable_swap(struct rpc_xprt *xprt)
 388{
 389        xprt->ops->disable_swap(xprt);
 390}
 391
 392/*
 393 * Transport switch helper functions
 394 */
 395int                     xprt_register_transport(struct xprt_class *type);
 396int                     xprt_unregister_transport(struct xprt_class *type);
 397int                     xprt_find_transport_ident(const char *);
 398void                    xprt_wait_for_reply_request_def(struct rpc_task *task);
 399void                    xprt_wait_for_reply_request_rtt(struct rpc_task *task);
 400void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 401void                    xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
 402bool                    xprt_write_space(struct rpc_xprt *xprt);
 403void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 404struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 405void                    xprt_update_rtt(struct rpc_task *task);
 406void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 407void                    xprt_pin_rqst(struct rpc_rqst *req);
 408void                    xprt_unpin_rqst(struct rpc_rqst *req);
 409void                    xprt_release_rqst_cong(struct rpc_task *task);
 410bool                    xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
 411void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 412void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 413void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 414
 415bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 416void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 417void                    xprt_release_write(struct rpc_xprt *, struct rpc_task *);
 418
 419/*
 420 * Reserved bit positions in xprt->state
 421 */
 422#define XPRT_LOCKED             (0)
 423#define XPRT_CONNECTED          (1)
 424#define XPRT_CONNECTING         (2)
 425#define XPRT_CLOSE_WAIT         (3)
 426#define XPRT_BOUND              (4)
 427#define XPRT_BINDING            (5)
 428#define XPRT_CLOSING            (6)
 429#define XPRT_OFFLINE            (7)
 430#define XPRT_REMOVE             (8)
 431#define XPRT_CONGESTED          (9)
 432#define XPRT_CWND_WAIT          (10)
 433#define XPRT_WRITE_SPACE        (11)
 434#define XPRT_SND_IS_COOKIE      (12)
 435
 436static inline void xprt_set_connected(struct rpc_xprt *xprt)
 437{
 438        set_bit(XPRT_CONNECTED, &xprt->state);
 439}
 440
 441static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 442{
 443        clear_bit(XPRT_CONNECTED, &xprt->state);
 444}
 445
 446static inline int xprt_connected(struct rpc_xprt *xprt)
 447{
 448        return test_bit(XPRT_CONNECTED, &xprt->state);
 449}
 450
 451static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 452{
 453        return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 454}
 455
 456static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 457{
 458        return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 459}
 460
 461static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 462{
 463        smp_mb__before_atomic();
 464        clear_bit(XPRT_CONNECTING, &xprt->state);
 465        smp_mb__after_atomic();
 466}
 467
 468static inline int xprt_connecting(struct rpc_xprt *xprt)
 469{
 470        return test_bit(XPRT_CONNECTING, &xprt->state);
 471}
 472
 473static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 474{
 475        return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 476}
 477
 478static inline void xprt_set_bound(struct rpc_xprt *xprt)
 479{
 480        test_and_set_bit(XPRT_BOUND, &xprt->state);
 481}
 482
 483static inline int xprt_bound(struct rpc_xprt *xprt)
 484{
 485        return test_bit(XPRT_BOUND, &xprt->state);
 486}
 487
 488static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 489{
 490        clear_bit(XPRT_BOUND, &xprt->state);
 491}
 492
 493static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 494{
 495        smp_mb__before_atomic();
 496        clear_bit(XPRT_BINDING, &xprt->state);
 497        smp_mb__after_atomic();
 498}
 499
 500static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 501{
 502        return test_and_set_bit(XPRT_BINDING, &xprt->state);
 503}
 504
 505#endif /* _LINUX_SUNRPC_XPRT_H */
 506