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  */
  23 struct rpc_procinfo;
  24 struct 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
  31 struct rpc_call_ops;
  32 struct rpc_wait_queue;
  33 struct 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  */
  43 struct 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 };
  89 #define tk_xprt                 tk_client->cl_xprt
  90
  91 /* support walking a list of tasks on a wait queue */
  92 #define task_for_each(task, pos, head) \
  93         list_for_each(pos, head) \
  94                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
  95
  96 #define task_for_first(task, head) \
  97         if (!list_empty(head) &&  \
  98             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
  99
 100 typedef void                    (*rpc_action)(struct rpc_task *);
 101
 102 struct rpc_call_ops {
 103         void (*rpc_call_prepare)(struct rpc_task *, void *);
 104         void (*rpc_call_done)(struct rpc_task *, void *);
 105         void (*rpc_release)(void *);
 106 };
 107
 108 struct rpc_task_setup {
 109         struct rpc_task *task;
 110         struct rpc_clnt *rpc_client;
 111         const struct rpc_message *rpc_message;
 112         const struct rpc_call_ops *callback_ops;
 113         void *callback_data;
 114         struct workqueue_struct *workqueue;
 115         unsigned short flags;
 116         signed char priority;
 117 };
 118
 119 /*
 120  * RPC task flags
 121  */
 122 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 123 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 124 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 125 #define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 126 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 127 #define RPC_TASK_KILLED         0x0100          /* task was killed */
 128 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 129 #define RPC_TASK_SOFTCONN       0x0400          /* Fail if can't connect */
 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)
 136 #define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 137
 138 #define RPC_TASK_RUNNING        0
 139 #define RPC_TASK_QUEUED         1
 140 #define RPC_TASK_ACTIVE         2
 141
 142 #define RPC_IS_RUNNING(t)       test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 143 #define rpc_set_running(t)      set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 144 #define rpc_test_and_set_running(t) \
 145                                 test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 146 #define rpc_clear_running(t)    \
 147         do { \
 148                 smp_mb__before_clear_bit(); \
 149                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 150                 smp_mb__after_clear_bit(); \
 151         } while (0)
 152
 153 #define RPC_IS_QUEUED(t)        test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 154 #define rpc_set_queued(t)       set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 155 #define rpc_clear_queued(t)     \
 156         do { \
 157                 smp_mb__before_clear_bit(); \
 158                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 159                 smp_mb__after_clear_bit(); \
 160         } while (0)
 161
 162 #define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 163
 164 /*
 165  * Task priorities.
 166  * Note: if you change these, you must also change
 167  * the task initialization definitions below.
 168  */
 169 #define RPC_PRIORITY_LOW        (-1)
 170 #define RPC_PRIORITY_NORMAL     (0)
 171 #define RPC_PRIORITY_HIGH       (1)
 172 #define RPC_PRIORITY_PRIVILEGED (2)
 173 #define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
 174
 175 struct rpc_timer {
 176         struct timer_list timer;
 177         struct list_head list;
 178         unsigned long expires;
 179 };
 180
 181 /*
 182  * RPC synchronization objects
 183  */
 184 struct rpc_wait_queue {
 185         spinlock_t              lock;
 186         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 187         pid_t                   owner;                  /* process id of last task serviced */
 188         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 189         unsigned char           priority;               /* current priority */
 190         unsigned char           count;                  /* # task groups remaining serviced so far */
 191         unsigned char           nr;                     /* # tasks remaining for cookie */
 192         unsigned short          qlen;                   /* total # tasks waiting in queue */
 193         struct rpc_timer        timer_list;
 194 #ifdef RPC_DEBUG
 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  */
 210 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 211 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 212 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 213                                 const struct rpc_call_ops *ops);
 214 void            rpc_put_task(struct rpc_task *);
 215 void            rpc_put_task_async(struct rpc_task *);
 216 void            rpc_exit_task(struct rpc_task *);
 217 void            rpc_exit(struct rpc_task *, int);
 218 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 219 void            rpc_killall_tasks(struct rpc_clnt *);
 220 void            rpc_execute(struct rpc_task *);
 221 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 222 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 223 void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 224 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 225                                         rpc_action action);
 226 void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 227                                         struct rpc_task *);
 228 void            rpc_wake_up(struct rpc_wait_queue *);
 229 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 230 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 231 int             rpc_queue_empty(struct rpc_wait_queue *);
 232 void            rpc_delay(struct rpc_task *, unsigned long);
 233 void *          rpc_malloc(struct rpc_task *, size_t);
 234 void            rpc_free(void *);
 235 int             rpciod_up(void);
 236 void            rpciod_down(void);
 237 int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 238 #ifdef RPC_DEBUG
 239 void            rpc_show_tasks(void);
 240 #endif
 241 int             rpc_init_mempool(void);
 242 void            rpc_destroy_mempool(void);
 243 extern struct workqueue_struct *rpciod_workqueue;
 244 void            rpc_prepare_task(struct rpc_task *task);
 245
 246 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 247 {
 248         return __rpc_wait_for_completion_task(task, NULL);
 249 }
 250
 251 static inline void rpc_task_set_priority(struct rpc_task *task, unsigned char prio)
 252 {
 253         task->tk_priority = prio - RPC_PRIORITY_LOW;
 254 }
 255
 256 static inline int rpc_task_has_priority(struct rpc_task *task, unsigned char prio)
 257 {
 258         return (task->tk_priority + RPC_PRIORITY_LOW == prio);
 259 }
 260
 261 #ifdef RPC_DEBUG
 262 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 263 {
 264         return ((q && q->name) ? q->name : "unknown");
 265 }
 266 #endif
 267
 268 #endif /* _LINUX_SUNRPC_SCHED_H_ */