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