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