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/rcupdate.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 rpc_wait_queue * rpc_waitq;      /* RPC wait queue we're on */
  37 };
  38
  39 /*
  40  * This is the RPC task struct
  41  */
  42 struct 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         unsigned long           tk_cookie;      /* Cookie for batching tasks */
  60
  61         /*
  62          * timeout_fn   to be executed by timer bottom half
  63          * callback     to be executed after waking up
  64          * action       next procedure for async tasks
  65          * tk_ops       caller callbacks
  66          */
  67         void                    (*tk_timeout_fn)(struct rpc_task *);
  68         void                    (*tk_callback)(struct rpc_task *);
  69         void                    (*tk_action)(struct rpc_task *);
  70         const struct rpc_call_ops *tk_ops;
  71         void *                  tk_calldata;
  72
  73         /*
  74          * tk_timer is used for async processing by the RPC scheduling
  75          * primitives. You should not access this directly unless
  76          * you have a pathological interest in kernel oopses.
  77          */
  78         struct timer_list       tk_timer;       /* kernel timer */
  79         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  80         unsigned short          tk_flags;       /* misc flags */
  81         unsigned char           tk_priority : 2;/* Task priority */
  82         unsigned long           tk_runstate;    /* Task run status */
  83         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  84                                                  * be any workqueue
  85                                                  */
  86         union {
  87                 struct work_struct      tk_work;        /* Async task work queue */
  88                 struct rpc_wait         tk_wait;        /* RPC wait */
  89                 struct rcu_head         tk_rcu;         /* for task deletion */
  90         } u;
  91
  92         unsigned short          tk_timeouts;    /* maj timeouts */
  93         size_t                  tk_bytes_sent;  /* total bytes sent */
  94         unsigned long           tk_start;       /* RPC task init timestamp */
  95         long                    tk_rtt;         /* round-trip time (jiffies) */
  96
  97 #ifdef RPC_DEBUG
  98         unsigned short          tk_pid;         /* debugging aid */
  99 #endif
 100 };
 101 #define tk_xprt                 tk_client->cl_xprt
 102
 103 /* support walking a list of tasks on a wait queue */
 104 #define task_for_each(task, pos, head) \
 105         list_for_each(pos, head) \
 106                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
 107
 108 #define task_for_first(task, head) \
 109         if (!list_empty(head) &&  \
 110             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),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_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_NOINTR         0x0400          /* uninterruptible task */
 132
 133 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 134 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 135 #define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 136 #define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 137 #define RPC_DO_CALLBACK(t)      ((t)->tk_callback != NULL)
 138 #define RPC_IS_SOFT(t)          ((t)->tk_flags & RPC_TASK_SOFT)
 139 #define RPC_TASK_UNINTERRUPTIBLE(t) ((t)->tk_flags & RPC_TASK_NOINTR)
 140
 141 #define RPC_TASK_RUNNING        0
 142 #define RPC_TASK_QUEUED         1
 143 #define RPC_TASK_WAKEUP         2
 144 #define RPC_TASK_HAS_TIMER      3
 145 #define RPC_TASK_ACTIVE         4
 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_start_wakeup(t) \
 168         (test_and_set_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate) == 0)
 169 #define rpc_finish_wakeup(t) \
 170         do { \
 171                 smp_mb__before_clear_bit(); \
 172                 clear_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate); \
 173                 smp_mb__after_clear_bit(); \
 174         } while (0)
 175
 176 #define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 177
 178 /*
 179  * Task priorities.
 180  * Note: if you change these, you must also change
 181  * the task initialization definitions below.
 182  */
 183 #define RPC_PRIORITY_LOW        0
 184 #define RPC_PRIORITY_NORMAL     1
 185 #define RPC_PRIORITY_HIGH       2
 186 #define RPC_NR_PRIORITY         (RPC_PRIORITY_HIGH+1)
 187
 188 /*
 189  * RPC synchronization objects
 190  */
 191 struct rpc_wait_queue {
 192         spinlock_t              lock;
 193         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 194         unsigned long           cookie;                 /* cookie of last task serviced */
 195         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 196         unsigned char           priority;               /* current priority */
 197         unsigned char           count;                  /* # task groups remaining serviced so far */
 198         unsigned char           nr;                     /* # tasks remaining for cookie */
 199         unsigned short          qlen;                   /* total # tasks waiting in queue */
 200 #ifdef RPC_DEBUG
 201         const char *            name;
 202 #endif
 203 };
 204
 205 /*
 206  * This is the # requests to send consecutively
 207  * from a single cookie.  The aim is to improve
 208  * performance of NFS operations such as read/write.
 209  */
 210 #define RPC_BATCH_COUNT                 16
 211
 212 #ifndef RPC_DEBUG
 213 # define RPC_WAITQ_INIT(var,qname) { \
 214                 .lock = __SPIN_LOCK_UNLOCKED(var.lock), \
 215                 .tasks = { \
 216                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 217                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 218                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 219                 }, \
 220         }
 221 #else
 222 # define RPC_WAITQ_INIT(var,qname) { \
 223                 .lock = __SPIN_LOCK_UNLOCKED(var.lock), \
 224                 .tasks = { \
 225                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 226                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 227                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 228                 }, \
 229                 .name = qname, \
 230         }
 231 #endif
 232 # define RPC_WAITQ(var,qname)      struct rpc_wait_queue var = RPC_WAITQ_INIT(var,qname)
 233
 234 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 235
 236 /*
 237  * Function prototypes
 238  */
 239 struct rpc_task *rpc_new_task(struct rpc_clnt *, int flags,
 240                                 const struct rpc_call_ops *ops, void *data);
 241 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
 242                                 const struct rpc_call_ops *ops, void *data);
 243 void            rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt,
 244                                 int flags, const struct rpc_call_ops *ops,
 245                                 void *data);
 246 void            rpc_put_task(struct rpc_task *);
 247 void            rpc_exit_task(struct rpc_task *);
 248 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 249 void            rpc_killall_tasks(struct rpc_clnt *);
 250 void            rpc_execute(struct rpc_task *);
 251 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 252 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 253 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 254                                         rpc_action action, rpc_action timer);
 255 void            rpc_wake_up_task(struct rpc_task *);
 256 void            rpc_wake_up(struct rpc_wait_queue *);
 257 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 258 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 259 void            rpc_delay(struct rpc_task *, unsigned long);
 260 void *          rpc_malloc(struct rpc_task *, size_t);
 261 void            rpc_free(void *);
 262 int             rpciod_up(void);
 263 void            rpciod_down(void);
 264 int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 265 #ifdef RPC_DEBUG
 266 void            rpc_show_tasks(void);
 267 #endif
 268 int             rpc_init_mempool(void);
 269 void            rpc_destroy_mempool(void);
 270 extern struct workqueue_struct *rpciod_workqueue;
 271
 272 static inline void rpc_exit(struct rpc_task *task, int status)
 273 {
 274         task->tk_status = status;
 275         task->tk_action = rpc_exit_task;
 276 }
 277
 278 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 279 {
 280         return __rpc_wait_for_completion_task(task, NULL);
 281 }
 282
 283 #ifdef RPC_DEBUG
 284 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 285 {
 286         return ((q && q->name) ? q->name : "unknown");
 287 }
 288 #endif
 289
 290 #endif /* _LINUX_SUNRPC_SCHED_H_ */