LXR linux/include/linux/sunrpc/sched.h

   1/*
   2 * linux/include/linux/sunrpc/sched.h
   3 *
   4 * Scheduling primitives for kernel Sun RPC.
   5 *
   6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   7 */
   8
   9#ifndef _LINUX_SUNRPC_SCHED_H_
  10#define _LINUX_SUNRPC_SCHED_H_
  11
  12#include <linux/timer.h>
  13#include <linux/ktime.h>
  14#include <linux/sunrpc/types.h>
  15#include <linux/spinlock.h>
  16#include <linux/wait.h>
  17#include <linux/workqueue.h>
  18#include <linux/sunrpc/xdr.h>
  19
  20/*
  21 * This is the actual RPC procedure call info.
  22 */
  23struct rpc_procinfo;
  24struct rpc_message {
  25        struct rpc_procinfo *   rpc_proc;       /* Procedure information */
  26        void *                  rpc_argp;       /* Arguments */
  27        void *                  rpc_resp;       /* Result */
  28        struct rpc_cred *       rpc_cred;       /* Credentials */
  29};
  30
  31struct rpc_call_ops;
  32struct rpc_wait_queue;
  33struct rpc_wait {
  34        struct list_head        list;           /* wait queue links */
  35        struct list_head        links;          /* Links to related tasks */
  36        struct list_head        timer_list;     /* Timer list */
  37        unsigned long           expires;
  38};
  39
  40/*
  41 * This is the RPC task struct
  42 */
  43struct rpc_task {
  44        atomic_t                tk_count;       /* Reference count */
  45        int                     tk_status;      /* result of last operation */
  46        struct list_head        tk_task;        /* global list of tasks */
  47
  48        /*
  49         * callback     to be executed after waking up
  50         * action       next procedure for async tasks
  51         */
  52        void                    (*tk_callback)(struct rpc_task *);
  53        void                    (*tk_action)(struct rpc_task *);
  54
  55        unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  56        unsigned long           tk_runstate;    /* Task run status */
  57
  58        struct rpc_wait_queue   *tk_waitqueue;  /* RPC wait queue we're on */
  59        union {
  60                struct work_struct      tk_work;        /* Async task work queue */
  61                struct rpc_wait         tk_wait;        /* RPC wait */
  62        } u;
  63
  64        /*
  65         * RPC call state
  66         */
  67        struct rpc_message      tk_msg;         /* RPC call info */
  68        void *                  tk_calldata;    /* Caller private data */
  69        const struct rpc_call_ops *tk_ops;      /* Caller callbacks */
  70
  71        struct rpc_clnt *       tk_client;      /* RPC client */
  72        struct rpc_xprt *       tk_xprt;        /* Transport */
  73
  74        struct rpc_rqst *       tk_rqstp;       /* RPC request */
  75
  76        struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  77                                                 * be any workqueue
  78                                                 */
  79        ktime_t                 tk_start;       /* RPC task init timestamp */
  80
  81        pid_t                   tk_owner;       /* Process id for batching tasks */
  82        unsigned short          tk_flags;       /* misc flags */
  83        unsigned short          tk_timeouts;    /* maj timeouts */
  84
  85#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
  86        unsigned short          tk_pid;         /* debugging aid */
  87#endif
  88        unsigned char           tk_priority : 2,/* Task priority */
  89                                tk_garb_retry : 2,
  90                                tk_cred_retry : 2,
  91                                tk_rebind_retry : 2;
  92};
  93
  94typedef void                    (*rpc_action)(struct rpc_task *);
  95
  96struct rpc_call_ops {
  97        void (*rpc_call_prepare)(struct rpc_task *, void *);
  98        void (*rpc_call_done)(struct rpc_task *, void *);
  99        void (*rpc_count_stats)(struct rpc_task *, void *);
 100        void (*rpc_release)(void *);
 101};
 102
 103struct rpc_task_setup {
 104        struct rpc_task *task;
 105        struct rpc_clnt *rpc_client;
 106        struct rpc_xprt *rpc_xprt;
 107        const struct rpc_message *rpc_message;
 108        const struct rpc_call_ops *callback_ops;
 109        void *callback_data;
 110        struct workqueue_struct *workqueue;
 111        unsigned short flags;
 112        signed char priority;
 113};
 114
 115/*
 116 * RPC task flags
 117 */
 118#define RPC_TASK_ASYNC          0x0001          /* is an async task */
 119#define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 120#define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 121#define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 122#define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 123#define RPC_TASK_KILLED         0x0100          /* task was killed */
 124#define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 125#define RPC_TASK_SOFTCONN       0x0400          /* Fail if can't connect */
 126#define RPC_TASK_SENT           0x0800          /* message was sent */
 127#define RPC_TASK_TIMEOUT        0x1000          /* fail with ETIMEDOUT on timeout */
 128#define RPC_TASK_NOCONNECT      0x2000          /* return ENOTCONN if not connected */
 129#define RPC_TASK_NO_RETRANS_TIMEOUT     0x4000          /* wait forever for a reply */
 130
 131#define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 132#define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 133#define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 134#define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 135#define RPC_IS_SOFT(t)          ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
 136#define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 137#define RPC_WAS_SENT(t)         ((t)->tk_flags & RPC_TASK_SENT)
 138
 139#define RPC_TASK_RUNNING        0
 140#define RPC_TASK_QUEUED         1
 141#define RPC_TASK_ACTIVE         2
 142
 143#define RPC_IS_RUNNING(t)       test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 144#define rpc_set_running(t)      set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 145#define rpc_test_and_set_running(t) \
 146                                test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 147#define rpc_clear_running(t)    \
 148        do { \
 149                smp_mb__before_atomic(); \
 150                clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 151                smp_mb__after_atomic(); \
 152        } while (0)
 153
 154#define RPC_IS_QUEUED(t)        test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 155#define rpc_set_queued(t)       set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 156#define rpc_clear_queued(t)     \
 157        do { \
 158                smp_mb__before_atomic(); \
 159                clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 160                smp_mb__after_atomic(); \
 161        } while (0)
 162
 163#define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 164
 165/*
 166 * Task priorities.
 167 * Note: if you change these, you must also change
 168 * the task initialization definitions below.
 169 */
 170#define RPC_PRIORITY_LOW        (-1)
 171#define RPC_PRIORITY_NORMAL     (0)
 172#define RPC_PRIORITY_HIGH       (1)
 173#define RPC_PRIORITY_PRIVILEGED (2)
 174#define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
 175
 176struct rpc_timer {
 177        struct timer_list timer;
 178        struct list_head list;
 179        unsigned long expires;
 180};
 181
 182/*
 183 * RPC synchronization objects
 184 */
 185struct rpc_wait_queue {
 186        spinlock_t              lock;
 187        struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 188        pid_t                   owner;                  /* process id of last task serviced */
 189        unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 190        unsigned char           priority;               /* current priority */
 191        unsigned char           nr;                     /* # tasks remaining for cookie */
 192        unsigned short          qlen;                   /* total # tasks waiting in queue */
 193        struct rpc_timer        timer_list;
 194#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 195        const char *            name;
 196#endif
 197};
 198
 199/*
 200 * This is the # requests to send consecutively
 201 * from a single cookie.  The aim is to improve
 202 * performance of NFS operations such as read/write.
 203 */
 204#define RPC_BATCH_COUNT                 16
 205#define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 206
 207/*
 208 * Function prototypes
 209 */
 210struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 211struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 212struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
 213void            rpc_put_task(struct rpc_task *);
 214void            rpc_put_task_async(struct rpc_task *);
 215void            rpc_exit_task(struct rpc_task *);
 216void            rpc_exit(struct rpc_task *, int);
 217void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 218void            rpc_killall_tasks(struct rpc_clnt *);
 219void            rpc_execute(struct rpc_task *);
 220void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 221void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 222void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 223void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 224                                        rpc_action action);
 225void            rpc_sleep_on_priority(struct rpc_wait_queue *,
 226                                        struct rpc_task *,
 227                                        rpc_action action,
 228                                        int priority);
 229void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 230                                        struct rpc_task *);
 231void            rpc_wake_up(struct rpc_wait_queue *);
 232struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 233struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
 234                                        bool (*)(struct rpc_task *, void *),
 235                                        void *);
 236void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 237void            rpc_delay(struct rpc_task *, unsigned long);
 238void *          rpc_malloc(struct rpc_task *, size_t);
 239void            rpc_free(void *);
 240int             rpciod_up(void);
 241void            rpciod_down(void);
 242int             __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
 243#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 244struct net;
 245void            rpc_show_tasks(struct net *);
 246#endif
 247int             rpc_init_mempool(void);
 248void            rpc_destroy_mempool(void);
 249extern struct workqueue_struct *rpciod_workqueue;
 250void            rpc_prepare_task(struct rpc_task *task);
 251
 252static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 253{
 254        return __rpc_wait_for_completion_task(task, NULL);
 255}
 256
 257#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 258static inline const char * rpc_qname(const struct rpc_wait_queue *q)
 259{
 260        return ((q && q->name) ? q->name : "unknown");
 261}
 262
 263static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 264                const char *name)
 265{
 266        q->name = name;
 267}
 268#else
 269static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 270                const char *name)
 271{
 272}
 273#endif
 274
 275#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
 276int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
 277void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
 278#else
 279static inline int
 280rpc_clnt_swap_activate(struct rpc_clnt *clnt)
 281{
 282        return -EINVAL;
 283}
 284
 285static inline void
 286rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
 287{
 288}
 289#endif /* CONFIG_SUNRPC_SWAP */
 290
 291#endif /* _LINUX_SUNRPC_SCHED_H_ */
 292