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  */
  22 struct rpc_procinfo;
  23 struct 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
  30 struct rpc_call_ops;
  31 struct rpc_wait_queue;
  32 struct rpc_wait {
  33         struct list_head        list;           /* wait queue links */
  34         struct list_head        links;          /* Links to related tasks */
  35         struct rpc_wait_queue * rpc_waitq;      /* RPC wait queue we're on */
  36 };
  37
  38 /*
  39  * This is the RPC task struct
  40  */
  41 struct rpc_task {
  42 #ifdef RPC_DEBUG
  43         unsigned long           tk_magic;       /* 0xf00baa */
  44 #endif
  45         atomic_t                tk_count;       /* Reference count */
  46         struct list_head        tk_task;        /* global list of tasks */
  47         struct rpc_clnt *       tk_client;      /* RPC client */
  48         struct rpc_rqst *       tk_rqstp;       /* RPC request */
  49         int                     tk_status;      /* result of last operation */
  50
  51         /*
  52          * RPC call state
  53          */
  54         struct rpc_message      tk_msg;         /* RPC call info */
  55         __u8                    tk_garb_retry;
  56         __u8                    tk_cred_retry;
  57
  58         unsigned long           tk_cookie;      /* Cookie for batching tasks */
  59
  60         /*
  61          * timeout_fn   to be executed by timer bottom half
  62          * callback     to be executed after waking up
  63          * action       next procedure for async tasks
  64          * tk_ops       caller callbacks
  65          */
  66         void                    (*tk_timeout_fn)(struct rpc_task *);
  67         void                    (*tk_callback)(struct rpc_task *);
  68         void                    (*tk_action)(struct rpc_task *);
  69         const struct rpc_call_ops *tk_ops;
  70         void *                  tk_calldata;
  71
  72         /*
  73          * tk_timer is used for async processing by the RPC scheduling
  74          * primitives. You should not access this directly unless
  75          * you have a pathological interest in kernel oopses.
  76          */
  77         struct timer_list       tk_timer;       /* kernel timer */
  78         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  79         unsigned short          tk_flags;       /* misc flags */
  80         unsigned char           tk_priority : 2;/* Task priority */
  81         unsigned long           tk_runstate;    /* Task run status */
  82         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  83                                                  * be any workqueue
  84                                                  */
  85         union {
  86                 struct work_struct      tk_work;        /* Async task work queue */
  87                 struct rpc_wait         tk_wait;        /* RPC wait */
  88         } u;
  89
  90         unsigned short          tk_timeouts;    /* maj timeouts */
  91         size_t                  tk_bytes_sent;  /* total bytes sent */
  92         unsigned long           tk_start;       /* RPC task init timestamp */
  93         long                    tk_rtt;         /* round-trip time (jiffies) */
  94
  95 #ifdef RPC_DEBUG
  96         unsigned short          tk_pid;         /* debugging aid */
  97 #endif
  98 };
  99 #define tk_auth                 tk_client->cl_auth
 100 #define tk_xprt                 tk_client->cl_xprt
 101
 102 /* support walking a list of tasks on a wait queue */
 103 #define task_for_each(task, pos, head) \
 104         list_for_each(pos, head) \
 105                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
 106
 107 #define task_for_first(task, head) \
 108         if (!list_empty(head) &&  \
 109             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
 110
 111 /* .. and walking list of all tasks */
 112 #define alltask_for_each(task, pos, head) \
 113         list_for_each(pos, head) \
 114                 if ((task=list_entry(pos, struct rpc_task, tk_task)),1)
 115
 116 typedef void                    (*rpc_action)(struct rpc_task *);
 117
 118 struct rpc_call_ops {
 119         void (*rpc_call_prepare)(struct rpc_task *, void *);
 120         void (*rpc_call_done)(struct rpc_task *, void *);
 121         void (*rpc_release)(void *);
 122 };
 123
 124
 125 /*
 126  * RPC task flags
 127  */
 128 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 129 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 130 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 131 #define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 132 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 133 #define RPC_TASK_KILLED         0x0100          /* task was killed */
 134 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 135 #define RPC_TASK_NOINTR         0x0400          /* uninterruptible task */
 136
 137 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 138 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 139 #define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 140 #define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 141 #define RPC_DO_CALLBACK(t)      ((t)->tk_callback != NULL)
 142 #define RPC_IS_SOFT(t)          ((t)->tk_flags & RPC_TASK_SOFT)
 143 #define RPC_TASK_UNINTERRUPTIBLE(t) ((t)->tk_flags & RPC_TASK_NOINTR)
 144
 145 #define RPC_TASK_RUNNING        0
 146 #define RPC_TASK_QUEUED         1
 147 #define RPC_TASK_WAKEUP         2
 148 #define RPC_TASK_HAS_TIMER      3
 149 #define RPC_TASK_ACTIVE         4
 150
 151 #define RPC_IS_RUNNING(t)       (test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 152 #define rpc_set_running(t)      (set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 153 #define rpc_test_and_set_running(t) \
 154                                 (test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 155 #define rpc_clear_running(t)    \
 156         do { \
 157                 smp_mb__before_clear_bit(); \
 158                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 159                 smp_mb__after_clear_bit(); \
 160         } while (0)
 161
 162 #define RPC_IS_QUEUED(t)        (test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate))
 163 #define rpc_set_queued(t)       (set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate))
 164 #define rpc_clear_queued(t)     \
 165         do { \
 166                 smp_mb__before_clear_bit(); \
 167                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 168                 smp_mb__after_clear_bit(); \
 169         } while (0)
 170
 171 #define rpc_start_wakeup(t) \
 172         (test_and_set_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate) == 0)
 173 #define rpc_finish_wakeup(t) \
 174         do { \
 175                 smp_mb__before_clear_bit(); \
 176                 clear_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate); \
 177                 smp_mb__after_clear_bit(); \
 178         } while (0)
 179
 180 #define RPC_IS_ACTIVATED(t)     (test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate))
 181 #define rpc_set_active(t)       (set_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate))
 182 #define rpc_clear_active(t)     \
 183         do { \
 184                 smp_mb__before_clear_bit(); \
 185                 clear_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate); \
 186                 smp_mb__after_clear_bit(); \
 187         } while(0)
 188
 189 /*
 190  * Task priorities.
 191  * Note: if you change these, you must also change
 192  * the task initialization definitions below.
 193  */
 194 #define RPC_PRIORITY_LOW        0
 195 #define RPC_PRIORITY_NORMAL     1
 196 #define RPC_PRIORITY_HIGH       2
 197 #define RPC_NR_PRIORITY         (RPC_PRIORITY_HIGH+1)
 198
 199 /*
 200  * RPC synchronization objects
 201  */
 202 struct rpc_wait_queue {
 203         spinlock_t              lock;
 204         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 205         unsigned long           cookie;                 /* cookie of last task serviced */
 206         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 207         unsigned char           priority;               /* current priority */
 208         unsigned char           count;                  /* # task groups remaining serviced so far */
 209         unsigned char           nr;                     /* # tasks remaining for cookie */
 210         unsigned short          qlen;                   /* total # tasks waiting in queue */
 211 #ifdef RPC_DEBUG
 212         const char *            name;
 213 #endif
 214 };
 215
 216 /*
 217  * This is the # requests to send consecutively
 218  * from a single cookie.  The aim is to improve
 219  * performance of NFS operations such as read/write.
 220  */
 221 #define RPC_BATCH_COUNT                 16
 222
 223 #ifndef RPC_DEBUG
 224 # define RPC_WAITQ_INIT(var,qname) { \
 225                 .lock = SPIN_LOCK_UNLOCKED, \
 226                 .tasks = { \
 227                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 228                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 229                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 230                 }, \
 231         }
 232 #else
 233 # define RPC_WAITQ_INIT(var,qname) { \
 234                 .lock = SPIN_LOCK_UNLOCKED, \
 235                 .tasks = { \
 236                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 237                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 238                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 239                 }, \
 240                 .name = qname, \
 241         }
 242 #endif
 243 # define RPC_WAITQ(var,qname)      struct rpc_wait_queue var = RPC_WAITQ_INIT(var,qname)
 244
 245 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 246
 247 /*
 248  * Function prototypes
 249  */
 250 struct rpc_task *rpc_new_task(struct rpc_clnt *, int flags,
 251                                 const struct rpc_call_ops *ops, void *data);
 252 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
 253                                 const struct rpc_call_ops *ops, void *data);
 254 void            rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt,
 255                                 int flags, const struct rpc_call_ops *ops,
 256                                 void *data);
 257 void            rpc_release_task(struct rpc_task *);
 258 void            rpc_exit_task(struct rpc_task *);
 259 void            rpc_killall_tasks(struct rpc_clnt *);
 260 int             rpc_execute(struct rpc_task *);
 261 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 262 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 263 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 264                                         rpc_action action, rpc_action timer);
 265 void            rpc_wake_up_task(struct rpc_task *);
 266 void            rpc_wake_up(struct rpc_wait_queue *);
 267 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 268 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 269 void            rpc_delay(struct rpc_task *, unsigned long);
 270 void *          rpc_malloc(struct rpc_task *, size_t);
 271 void            rpc_free(struct rpc_task *);
 272 int             rpciod_up(void);
 273 void            rpciod_down(void);
 274 int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 275 #ifdef RPC_DEBUG
 276 void            rpc_show_tasks(void);
 277 #endif
 278 int             rpc_init_mempool(void);
 279 void            rpc_destroy_mempool(void);
 280 extern struct workqueue_struct *rpciod_workqueue;
 281
 282 static inline void rpc_exit(struct rpc_task *task, int status)
 283 {
 284         task->tk_status = status;
 285         task->tk_action = rpc_exit_task;
 286 }
 287
 288 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 289 {
 290         return __rpc_wait_for_completion_task(task, NULL);
 291 }
 292
 293 #ifdef RPC_DEBUG
 294 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 295 {
 296         return ((q && q->name) ? q->name : "unknown");
 297 }
 298 #endif
 299
 300 #endif /* _LINUX_SUNRPC_SCHED_H_ */