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/sunrpc/types.h>
  14#include <linux/spinlock.h>
  15#include <linux/wait.h>
  16#include <linux/workqueue.h>
  17#include <linux/sunrpc/xdr.h>
  18
  19/*
  20 * This is the actual RPC procedure call info.
  21 */
  22struct rpc_procinfo;
  23struct rpc_message {
  24        struct rpc_procinfo *   rpc_proc;       /* Procedure information */
  25        void *                  rpc_argp;       /* Arguments */
  26        void *                  rpc_resp;       /* Result */
  27        struct rpc_cred *       rpc_cred;       /* Credentials */
  28};
  29
  30struct rpc_call_ops;
  31struct rpc_wait_queue;
  32struct rpc_wait {
  33        struct list_head        list;           /* wait queue links */
  34        struct list_head        links;          /* Links to related tasks */
  35        struct list_head        timer_list;     /* Timer list */
  36        unsigned long           expires;
  37};
  38
  39/*
  40 * This is the RPC task struct
  41 */
  42struct rpc_task {
  43#ifdef RPC_DEBUG
  44        unsigned long           tk_magic;       /* 0xf00baa */
  45#endif
  46        atomic_t                tk_count;       /* Reference count */
  47        struct list_head        tk_task;        /* global list of tasks */
  48        struct rpc_clnt *       tk_client;      /* RPC client */
  49        struct rpc_rqst *       tk_rqstp;       /* RPC request */
  50        int                     tk_status;      /* result of last operation */
  51
  52        /*
  53         * RPC call state
  54         */
  55        struct rpc_message      tk_msg;         /* RPC call info */
  56        __u8                    tk_garb_retry;
  57        __u8                    tk_cred_retry;
  58
  59        /*
  60         * callback     to be executed after waking up
  61         * action       next procedure for async tasks
  62         * tk_ops       caller callbacks
  63         */
  64        void                    (*tk_callback)(struct rpc_task *);
  65        void                    (*tk_action)(struct rpc_task *);
  66        const struct rpc_call_ops *tk_ops;
  67        void *                  tk_calldata;
  68
  69        unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  70        unsigned short          tk_flags;       /* misc flags */
  71        unsigned long           tk_runstate;    /* Task run status */
  72        struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  73                                                 * be any workqueue
  74                                                 */
  75        struct rpc_wait_queue   *tk_waitqueue;  /* RPC wait queue we're on */
  76        union {
  77                struct work_struct      tk_work;        /* Async task work queue */
  78                struct rpc_wait         tk_wait;        /* RPC wait */
  79        } u;
  80
  81        unsigned short          tk_timeouts;    /* maj timeouts */
  82        size_t                  tk_bytes_sent;  /* total bytes sent */
  83        unsigned long           tk_start;       /* RPC task init timestamp */
  84        long                    tk_rtt;         /* round-trip time (jiffies) */
  85
  86        pid_t                   tk_owner;       /* Process id for batching tasks */
  87        unsigned char           tk_priority : 2;/* Task priority */
  88
  89#ifdef RPC_DEBUG
  90        unsigned short          tk_pid;         /* debugging aid */
  91#endif
  92};
  93#define tk_xprt                 tk_client->cl_xprt
  94
  95/* support walking a list of tasks on a wait queue */
  96#define task_for_each(task, pos, head) \
  97        list_for_each(pos, head) \
  98                if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
  99
 100#define task_for_first(task, head) \
 101        if (!list_empty(head) &&  \
 102            ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
 103
 104typedef void                    (*rpc_action)(struct rpc_task *);
 105
 106struct rpc_call_ops {
 107        void (*rpc_call_prepare)(struct rpc_task *, void *);
 108        void (*rpc_call_done)(struct rpc_task *, void *);
 109        void (*rpc_release)(void *);
 110};
 111
 112struct rpc_task_setup {
 113        struct rpc_task *task;
 114        struct rpc_clnt *rpc_client;
 115        const struct rpc_message *rpc_message;
 116        const struct rpc_call_ops *callback_ops;
 117        void *callback_data;
 118        struct workqueue_struct *workqueue;
 119        unsigned short flags;
 120        signed char priority;
 121};
 122
 123/*
 124 * RPC task flags
 125 */
 126#define RPC_TASK_ASYNC          0x0001          /* is an async task */
 127#define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 128#define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 129#define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 130#define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 131#define RPC_TASK_KILLED         0x0100          /* task was killed */
 132#define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 133
 134#define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 135#define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 136#define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 137#define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 138#define RPC_IS_SOFT(t)          ((t)->tk_flags & RPC_TASK_SOFT)
 139
 140#define RPC_TASK_RUNNING        0
 141#define RPC_TASK_QUEUED         1
 142#define RPC_TASK_ACTIVE         2
 143
 144#define RPC_IS_RUNNING(t)       test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 145#define rpc_set_running(t)      set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 146#define rpc_test_and_set_running(t) \
 147                                test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 148#define rpc_clear_running(t)    \
 149        do { \
 150                smp_mb__before_clear_bit(); \
 151                clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 152                smp_mb__after_clear_bit(); \
 153        } while (0)
 154
 155#define RPC_IS_QUEUED(t)        test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 156#define rpc_set_queued(t)       set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 157#define rpc_clear_queued(t)     \
 158        do { \
 159                smp_mb__before_clear_bit(); \
 160                clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 161                smp_mb__after_clear_bit(); \
 162        } while (0)
 163
 164#define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 165
 166/*
 167 * Task priorities.
 168 * Note: if you change these, you must also change
 169 * the task initialization definitions below.
 170 */
 171#define RPC_PRIORITY_LOW        (-1)
 172#define RPC_PRIORITY_NORMAL     (0)
 173#define RPC_PRIORITY_HIGH       (1)
 174#define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_HIGH - 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           count;                  /* # task groups remaining serviced so far */
 192        unsigned char           nr;                     /* # tasks remaining for cookie */
 193        unsigned short          qlen;                   /* total # tasks waiting in queue */
 194        struct rpc_timer        timer_list;
 195#ifdef RPC_DEBUG
 196        const char *            name;
 197#endif
 198};
 199
 200/*
 201 * This is the # requests to send consecutively
 202 * from a single cookie.  The aim is to improve
 203 * performance of NFS operations such as read/write.
 204 */
 205#define RPC_BATCH_COUNT                 16
 206#define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 207
 208/*
 209 * Function prototypes
 210 */
 211struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 212struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 213struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 214                                const struct rpc_call_ops *ops);
 215void            rpc_put_task(struct rpc_task *);
 216void            rpc_exit_task(struct rpc_task *);
 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_wake_up_queued_task(struct rpc_wait_queue *,
 226                                        struct rpc_task *);
 227void            rpc_wake_up(struct rpc_wait_queue *);
 228struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 229void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 230void            rpc_delay(struct rpc_task *, unsigned long);
 231void *          rpc_malloc(struct rpc_task *, size_t);
 232void            rpc_free(void *);
 233int             rpciod_up(void);
 234void            rpciod_down(void);
 235int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 236#ifdef RPC_DEBUG
 237void            rpc_show_tasks(void);
 238#endif
 239int             rpc_init_mempool(void);
 240void            rpc_destroy_mempool(void);
 241extern struct workqueue_struct *rpciod_workqueue;
 242void            rpc_prepare_task(struct rpc_task *task);
 243
 244static inline void rpc_exit(struct rpc_task *task, int status)
 245{
 246        task->tk_status = status;
 247        task->tk_action = rpc_exit_task;
 248}
 249
 250static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 251{
 252        return __rpc_wait_for_completion_task(task, NULL);
 253}
 254
 255#ifdef RPC_DEBUG
 256static inline const char * rpc_qname(struct rpc_wait_queue *q)
 257{
 258        return ((q && q->name) ? q->name : "unknown");
 259}
 260#endif
 261
 262#endif /* _LINUX_SUNRPC_SCHED_H_ */
 263