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                                 tk_rebind_retry : 2;
  89 };
  90 #define tk_xprt                 tk_client->cl_xprt
  91
  92 /* support walking a list of tasks on a wait queue */
  93 #define task_for_each(task, pos, head) \
  94         list_for_each(pos, head) \
  95                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
  96
  97 #define task_for_first(task, head) \
  98         if (!list_empty(head) &&  \
  99             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
 100
 101 typedef void                    (*rpc_action)(struct rpc_task *);
 102
 103 struct rpc_call_ops {
 104         void (*rpc_call_prepare)(struct rpc_task *, void *);
 105         void (*rpc_call_done)(struct rpc_task *, void *);
 106         void (*rpc_count_stats)(struct rpc_task *, void *);
 107         void (*rpc_release)(void *);
 108 };
 109
 110 struct rpc_task_setup {
 111         struct rpc_task *task;
 112         struct rpc_clnt *rpc_client;
 113         const struct rpc_message *rpc_message;
 114         const struct rpc_call_ops *callback_ops;
 115         void *callback_data;
 116         struct workqueue_struct *workqueue;
 117         unsigned short flags;
 118         signed char priority;
 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_SOFTCONN       0x0400          /* Fail if can't connect */
 132 #define RPC_TASK_SENT           0x0800          /* message was sent */
 133 #define RPC_TASK_TIMEOUT        0x1000          /* fail with ETIMEDOUT on timeout */
 134
 135 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 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_IS_SOFT(t)          ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
 140 #define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 141 #define RPC_WAS_SENT(t)         ((t)->tk_flags & RPC_TASK_SENT)
 142
 143 #define RPC_TASK_RUNNING        0
 144 #define RPC_TASK_QUEUED         1
 145 #define RPC_TASK_ACTIVE         2
 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_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 168
 169 /*
 170  * Task priorities.
 171  * Note: if you change these, you must also change
 172  * the task initialization definitions below.
 173  */
 174 #define RPC_PRIORITY_LOW        (-1)
 175 #define RPC_PRIORITY_NORMAL     (0)
 176 #define RPC_PRIORITY_HIGH       (1)
 177 #define RPC_PRIORITY_PRIVILEGED (2)
 178 #define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
 179
 180 struct rpc_timer {
 181         struct timer_list timer;
 182         struct list_head list;
 183         unsigned long expires;
 184 };
 185
 186 /*
 187  * RPC synchronization objects
 188  */
 189 struct rpc_wait_queue {
 190         spinlock_t              lock;
 191         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 192         pid_t                   owner;                  /* process id of last task serviced */
 193         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 194         unsigned char           priority;               /* current priority */
 195         unsigned char           count;                  /* # task groups remaining serviced so far */
 196         unsigned char           nr;                     /* # tasks remaining for cookie */
 197         unsigned short          qlen;                   /* total # tasks waiting in queue */
 198         struct rpc_timer        timer_list;
 199 #if defined(RPC_DEBUG) || defined(RPC_TRACEPOINTS)
 200         const char *            name;
 201 #endif
 202 };
 203
 204 /*
 205  * This is the # requests to send consecutively
 206  * from a single cookie.  The aim is to improve
 207  * performance of NFS operations such as read/write.
 208  */
 209 #define RPC_BATCH_COUNT                 16
 210 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 211
 212 /*
 213  * Function prototypes
 214  */
 215 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 216 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 217 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 218                                 const struct rpc_call_ops *ops);
 219 void            rpc_put_task(struct rpc_task *);
 220 void            rpc_put_task_async(struct rpc_task *);
 221 void            rpc_exit_task(struct rpc_task *);
 222 void            rpc_exit(struct rpc_task *, int);
 223 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 224 void            rpc_killall_tasks(struct rpc_clnt *);
 225 void            rpc_execute(struct rpc_task *);
 226 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 227 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 228 void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 229 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 230                                         rpc_action action);
 231 void            rpc_sleep_on_priority(struct rpc_wait_queue *,
 232                                         struct rpc_task *,
 233                                         rpc_action action,
 234                                         int priority);
 235 void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 236                                         struct rpc_task *);
 237 void            rpc_wake_up(struct rpc_wait_queue *);
 238 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 239 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
 240                                         bool (*)(struct rpc_task *, void *),
 241                                         void *);
 242 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 243 int             rpc_queue_empty(struct rpc_wait_queue *);
 244 void            rpc_delay(struct rpc_task *, unsigned long);
 245 void *          rpc_malloc(struct rpc_task *, size_t);
 246 void            rpc_free(void *);
 247 int             rpciod_up(void);
 248 void            rpciod_down(void);
 249 int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 250 #ifdef RPC_DEBUG
 251 struct net;
 252 void            rpc_show_tasks(struct net *);
 253 #endif
 254 int             rpc_init_mempool(void);
 255 void            rpc_destroy_mempool(void);
 256 extern struct workqueue_struct *rpciod_workqueue;
 257 void            rpc_prepare_task(struct rpc_task *task);
 258
 259 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 260 {
 261         return __rpc_wait_for_completion_task(task, NULL);
 262 }
 263
 264 static inline void rpc_task_set_priority(struct rpc_task *task, unsigned char prio)
 265 {
 266         task->tk_priority = prio - RPC_PRIORITY_LOW;
 267 }
 268
 269 static inline int rpc_task_has_priority(struct rpc_task *task, unsigned char prio)
 270 {
 271         return (task->tk_priority + RPC_PRIORITY_LOW == prio);
 272 }
 273
 274 #if defined(RPC_DEBUG) || defined (RPC_TRACEPOINTS)
 275 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
 276 {
 277         return ((q && q->name) ? q->name : "unknown");
 278 }
 279
 280 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 281                 const char *name)
 282 {
 283         q->name = name;
 284 }
 285 #else
 286 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 287                 const char *name)
 288 {
 289 }
 290 #endif
 291
 292 #endif /* _LINUX_SUNRPC_SCHED_H_ */