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         __u32 *                 tk_buffer;      /* XDR buffer */
  56         size_t                  tk_bufsize;
  57         __u8                    tk_garb_retry;
  58         __u8                    tk_cred_retry;
  59
  60         unsigned long           tk_cookie;      /* Cookie for batching tasks */
  61
  62         /*
  63          * timeout_fn   to be executed by timer bottom half
  64          * callback     to be executed after waking up
  65          * action       next procedure for async tasks
  66          * tk_ops       caller callbacks
  67          */
  68         void                    (*tk_timeout_fn)(struct rpc_task *);
  69         void                    (*tk_callback)(struct rpc_task *);
  70         void                    (*tk_action)(struct rpc_task *);
  71         const struct rpc_call_ops *tk_ops;
  72         void *                  tk_calldata;
  73
  74         /*
  75          * tk_timer is used for async processing by the RPC scheduling
  76          * primitives. You should not access this directly unless
  77          * you have a pathological interest in kernel oopses.
  78          */
  79         struct timer_list       tk_timer;       /* kernel timer */
  80         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  81         unsigned short          tk_flags;       /* misc flags */
  82         unsigned char           tk_priority : 2;/* Task priority */
  83         unsigned long           tk_runstate;    /* Task run status */
  84         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  85                                                  * be any workqueue
  86                                                  */
  87         union {
  88                 struct work_struct      tk_work;        /* Async task work queue */
  89                 struct rpc_wait         tk_wait;        /* RPC wait */
  90         } u;
  91 #ifdef RPC_DEBUG
  92         unsigned short          tk_pid;         /* debugging aid */
  93 #endif
  94 };
  95 #define tk_auth                 tk_client->cl_auth
  96 #define tk_xprt                 tk_client->cl_xprt
  97
  98 /* support walking a list of tasks on a wait queue */
  99 #define task_for_each(task, pos, head) \
 100         list_for_each(pos, head) \
 101                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
 102
 103 #define task_for_first(task, head) \
 104         if (!list_empty(head) &&  \
 105             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
 106
 107 /* .. and walking list of all tasks */
 108 #define alltask_for_each(task, pos, head) \
 109         list_for_each(pos, head) \
 110                 if ((task=list_entry(pos, struct rpc_task, tk_task)),1)
 111
 112 typedef void                    (*rpc_action)(struct rpc_task *);
 113
 114 struct rpc_call_ops {
 115         void (*rpc_call_prepare)(struct rpc_task *, void *);
 116         void (*rpc_call_done)(struct rpc_task *, void *);
 117         void (*rpc_release)(void *);
 118 };
 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_TASK_CHILD          0x0008          /* is child of other task */
 127 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 128 #define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 129 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 130 #define RPC_TASK_KILLED         0x0100          /* task was killed */
 131 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 132 #define RPC_TASK_NOINTR         0x0400          /* uninterruptible task */
 133
 134 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 135 #define RPC_IS_CHILD(t)         ((t)->tk_flags & RPC_TASK_CHILD)
 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_DO_CALLBACK(t)      ((t)->tk_callback != NULL)
 140 #define RPC_IS_SOFT(t)          ((t)->tk_flags & RPC_TASK_SOFT)
 141 #define RPC_TASK_UNINTERRUPTIBLE(t) ((t)->tk_flags & RPC_TASK_NOINTR)
 142
 143 #define RPC_TASK_RUNNING        0
 144 #define RPC_TASK_QUEUED         1
 145 #define RPC_TASK_WAKEUP         2
 146 #define RPC_TASK_HAS_TIMER      3
 147 #define RPC_TASK_ACTIVE         4
 148
 149 #define RPC_IS_RUNNING(t)       (test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 150 #define rpc_set_running(t)      (set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 151 #define rpc_test_and_set_running(t) \
 152                                 (test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 153 #define rpc_clear_running(t)    \
 154         do { \
 155                 smp_mb__before_clear_bit(); \
 156                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 157                 smp_mb__after_clear_bit(); \
 158         } while (0)
 159
 160 #define RPC_IS_QUEUED(t)        (test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate))
 161 #define rpc_set_queued(t)       (set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate))
 162 #define rpc_clear_queued(t)     \
 163         do { \
 164                 smp_mb__before_clear_bit(); \
 165                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 166                 smp_mb__after_clear_bit(); \
 167         } while (0)
 168
 169 #define rpc_start_wakeup(t) \
 170         (test_and_set_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate) == 0)
 171 #define rpc_finish_wakeup(t) \
 172         do { \
 173                 smp_mb__before_clear_bit(); \
 174                 clear_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate); \
 175                 smp_mb__after_clear_bit(); \
 176         } while (0)
 177
 178 #define RPC_IS_ACTIVATED(t)     (test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate))
 179 #define rpc_set_active(t)       (set_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate))
 180 #define rpc_clear_active(t)     \
 181         do { \
 182                 smp_mb__before_clear_bit(); \
 183                 clear_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate); \
 184                 smp_mb__after_clear_bit(); \
 185         } while(0)
 186
 187 /*
 188  * Task priorities.
 189  * Note: if you change these, you must also change
 190  * the task initialization definitions below.
 191  */
 192 #define RPC_PRIORITY_LOW        0
 193 #define RPC_PRIORITY_NORMAL     1
 194 #define RPC_PRIORITY_HIGH       2
 195 #define RPC_NR_PRIORITY         (RPC_PRIORITY_HIGH+1)
 196
 197 /*
 198  * RPC synchronization objects
 199  */
 200 struct rpc_wait_queue {
 201         spinlock_t              lock;
 202         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 203         unsigned long           cookie;                 /* cookie of last task serviced */
 204         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 205         unsigned char           priority;               /* current priority */
 206         unsigned char           count;                  /* # task groups remaining serviced so far */
 207         unsigned char           nr;                     /* # tasks remaining for cookie */
 208 #ifdef RPC_DEBUG
 209         const char *            name;
 210 #endif
 211 };
 212
 213 /*
 214  * This is the # requests to send consecutively
 215  * from a single cookie.  The aim is to improve
 216  * performance of NFS operations such as read/write.
 217  */
 218 #define RPC_BATCH_COUNT                 16
 219
 220 #ifndef RPC_DEBUG
 221 # define RPC_WAITQ_INIT(var,qname) { \
 222                 .lock = SPIN_LOCK_UNLOCKED, \
 223                 .tasks = { \
 224                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 225                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 226                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 227                 }, \
 228         }
 229 #else
 230 # define RPC_WAITQ_INIT(var,qname) { \
 231                 .lock = SPIN_LOCK_UNLOCKED, \
 232                 .tasks = { \
 233                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 234                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 235                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 236                 }, \
 237                 .name = qname, \
 238         }
 239 #endif
 240 # define RPC_WAITQ(var,qname)      struct rpc_wait_queue var = RPC_WAITQ_INIT(var,qname)
 241
 242 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 243
 244 /*
 245  * Function prototypes
 246  */
 247 struct rpc_task *rpc_new_task(struct rpc_clnt *, int flags,
 248                                 const struct rpc_call_ops *ops, void *data);
 249 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
 250                                 const struct rpc_call_ops *ops, void *data);
 251 struct rpc_task *rpc_new_child(struct rpc_clnt *, struct rpc_task *parent);
 252 void            rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt,
 253                                 int flags, const struct rpc_call_ops *ops,
 254                                 void *data);
 255 void            rpc_release_task(struct rpc_task *);
 256 void            rpc_exit_task(struct rpc_task *);
 257 void            rpc_killall_tasks(struct rpc_clnt *);
 258 int             rpc_execute(struct rpc_task *);
 259 void            rpc_run_child(struct rpc_task *parent, struct rpc_task *child,
 260                                         rpc_action action);
 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 int             rpciod_up(void);
 272 void            rpciod_down(void);
 273 void            rpciod_wake_up(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
 281 static inline void rpc_exit(struct rpc_task *task, int status)
 282 {
 283         task->tk_status = status;
 284         task->tk_action = rpc_exit_task;
 285 }
 286
 287 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 288 {
 289         return __rpc_wait_for_completion_task(task, NULL);
 290 }
 291
 292 #ifdef RPC_DEBUG
 293 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 294 {
 295         return ((q && q->name) ? q->name : "unknown");
 296 }
 297 #endif
 298
 299 #endif /* _LINUX_SUNRPC_SCHED_H_ */