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 list_head        timer_list;     /* Timer list */
  36         unsigned long           expires;
  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         __u8                    tk_rebind_retry;
  59
  60         /*
  61          * callback     to be executed after waking up
  62          * action       next procedure for async tasks
  63          * tk_ops       caller callbacks
  64          */
  65         void                    (*tk_callback)(struct rpc_task *);
  66         void                    (*tk_action)(struct rpc_task *);
  67         const struct rpc_call_ops *tk_ops;
  68         void *                  tk_calldata;
  69
  70         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  71         unsigned short          tk_flags;       /* misc flags */
  72         unsigned long           tk_runstate;    /* Task run status */
  73         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  74                                                  * be any workqueue
  75                                                  */
  76         struct rpc_wait_queue   *tk_waitqueue;  /* RPC wait queue we're on */
  77         union {
  78                 struct work_struct      tk_work;        /* Async task work queue */
  79                 struct rpc_wait         tk_wait;        /* RPC wait */
  80         } u;
  81
  82         unsigned short          tk_timeouts;    /* maj timeouts */
  83         size_t                  tk_bytes_sent;  /* total bytes sent */
  84         unsigned long           tk_start;       /* RPC task init timestamp */
  85         long                    tk_rtt;         /* round-trip time (jiffies) */
  86
  87         pid_t                   tk_owner;       /* Process id for batching tasks */
  88         unsigned char           tk_priority : 2;/* Task priority */
  89
  90 #ifdef RPC_DEBUG
  91         unsigned short          tk_pid;         /* debugging aid */
  92 #endif
  93 };
  94 #define tk_xprt                 tk_client->cl_xprt
  95
  96 /* support walking a list of tasks on a wait queue */
  97 #define task_for_each(task, pos, head) \
  98         list_for_each(pos, head) \
  99                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
 100
 101 #define task_for_first(task, head) \
 102         if (!list_empty(head) &&  \
 103             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
 104
 105 typedef void                    (*rpc_action)(struct rpc_task *);
 106
 107 struct rpc_call_ops {
 108         void (*rpc_call_prepare)(struct rpc_task *, void *);
 109         void (*rpc_call_done)(struct rpc_task *, void *);
 110         void (*rpc_release)(void *);
 111 };
 112
 113 struct rpc_task_setup {
 114         struct rpc_task *task;
 115         struct rpc_clnt *rpc_client;
 116         const struct rpc_message *rpc_message;
 117         const struct rpc_call_ops *callback_ops;
 118         void *callback_data;
 119         struct workqueue_struct *workqueue;
 120         unsigned short flags;
 121         signed char priority;
 122 };
 123
 124 /*
 125  * RPC task flags
 126  */
 127 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 128 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 129 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 130 #define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 131 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 132 #define RPC_TASK_KILLED         0x0100          /* task was killed */
 133 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 134 #define RPC_TASK_SOFTCONN       0x0400          /* Fail if can't connect */
 135
 136 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 137 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 138 #define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 139 #define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 140 #define RPC_IS_SOFT(t)          ((t)->tk_flags & RPC_TASK_SOFT)
 141 #define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 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 #ifdef RPC_DEBUG
 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_exit_task(struct rpc_task *);
 221 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 222 void            rpc_killall_tasks(struct rpc_clnt *);
 223 void            rpc_execute(struct rpc_task *);
 224 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 225 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 226 void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 227 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 228                                         rpc_action action);
 229 void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 230                                         struct rpc_task *);
 231 void            rpc_wake_up(struct rpc_wait_queue *);
 232 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 233 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 234 int             rpc_queue_empty(struct rpc_wait_queue *);
 235 void            rpc_delay(struct rpc_task *, unsigned long);
 236 void *          rpc_malloc(struct rpc_task *, size_t);
 237 void            rpc_free(void *);
 238 int             rpciod_up(void);
 239 void            rpciod_down(void);
 240 int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 241 #ifdef RPC_DEBUG
 242 void            rpc_show_tasks(void);
 243 #endif
 244 int             rpc_init_mempool(void);
 245 void            rpc_destroy_mempool(void);
 246 extern struct workqueue_struct *rpciod_workqueue;
 247 void            rpc_prepare_task(struct rpc_task *task);
 248
 249 static inline void rpc_exit(struct rpc_task *task, int status)
 250 {
 251         task->tk_status = status;
 252         task->tk_action = rpc_exit_task;
 253 }
 254
 255 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 256 {
 257         return __rpc_wait_for_completion_task(task, NULL);
 258 }
 259
 260 static inline void rpc_task_set_priority(struct rpc_task *task, unsigned char prio)
 261 {
 262         task->tk_priority = prio - RPC_PRIORITY_LOW;
 263 }
 264
 265 static inline int rpc_task_has_priority(struct rpc_task *task, unsigned char prio)
 266 {
 267         return (task->tk_priority + RPC_PRIORITY_LOW == prio);
 268 }
 269
 270 #ifdef RPC_DEBUG
 271 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 272 {
 273         return ((q && q->name) ? q->name : "unknown");
 274 }
 275 #endif
 276
 277 #endif /* _LINUX_SUNRPC_SCHED_H_ */