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
  59         /*
  60          * callback     to be executed after waking up
  61          * action       next procedure for async tasks
  62          * tk_ops       caller callbacks
  63          */
  64         void                    (*tk_callback)(struct rpc_task *);
  65         void                    (*tk_action)(struct rpc_task *);
  66         const struct rpc_call_ops *tk_ops;
  67         void *                  tk_calldata;
  68
  69         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  70         unsigned short          tk_flags;       /* misc flags */
  71         unsigned long           tk_runstate;    /* Task run status */
  72         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  73                                                  * be any workqueue
  74                                                  */
  75         struct rpc_wait_queue   *tk_waitqueue;  /* RPC wait queue we're on */
  76         union {
  77                 struct work_struct      tk_work;        /* Async task work queue */
  78                 struct rpc_wait         tk_wait;        /* RPC wait */
  79         } u;
  80
  81         unsigned short          tk_timeouts;    /* maj timeouts */
  82         size_t                  tk_bytes_sent;  /* total bytes sent */
  83         unsigned long           tk_start;       /* RPC task init timestamp */
  84         long                    tk_rtt;         /* round-trip time (jiffies) */
  85
  86         pid_t                   tk_owner;       /* Process id for batching tasks */
  87         unsigned char           tk_priority : 2;/* Task priority */
  88
  89 #ifdef RPC_DEBUG
  90         unsigned short          tk_pid;         /* debugging aid */
  91 #endif
  92 };
  93 #define tk_xprt                 tk_client->cl_xprt
  94
  95 /* support walking a list of tasks on a wait queue */
  96 #define task_for_each(task, pos, head) \
  97         list_for_each(pos, head) \
  98                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
  99
 100 #define task_for_first(task, head) \
 101         if (!list_empty(head) &&  \
 102             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
 103
 104 typedef void                    (*rpc_action)(struct rpc_task *);
 105
 106 struct rpc_call_ops {
 107         void (*rpc_call_prepare)(struct rpc_task *, void *);
 108         void (*rpc_call_done)(struct rpc_task *, void *);
 109         void (*rpc_release)(void *);
 110 };
 111
 112 struct rpc_task_setup {
 113         struct rpc_task *task;
 114         struct rpc_clnt *rpc_client;
 115         const struct rpc_message *rpc_message;
 116         const struct rpc_call_ops *callback_ops;
 117         void *callback_data;
 118         struct workqueue_struct *workqueue;
 119         unsigned short flags;
 120         signed char priority;
 121 };
 122
 123 /*
 124  * RPC task flags
 125  */
 126 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 127 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 128 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 129 #define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 130 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 131 #define RPC_TASK_KILLED         0x0100          /* task was killed */
 132 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 133 #define RPC_TASK_SOFTCONN       0x0400          /* Fail if can't connect */
 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)
 140 #define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 141
 142 #define RPC_TASK_RUNNING        0
 143 #define RPC_TASK_QUEUED         1
 144 #define RPC_TASK_ACTIVE         2
 145
 146 #define RPC_IS_RUNNING(t)       test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 147 #define rpc_set_running(t)      set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 148 #define rpc_test_and_set_running(t) \
 149                                 test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 150 #define rpc_clear_running(t)    \
 151         do { \
 152                 smp_mb__before_clear_bit(); \
 153                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 154                 smp_mb__after_clear_bit(); \
 155         } while (0)
 156
 157 #define RPC_IS_QUEUED(t)        test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 158 #define rpc_set_queued(t)       set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 159 #define rpc_clear_queued(t)     \
 160         do { \
 161                 smp_mb__before_clear_bit(); \
 162                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 163                 smp_mb__after_clear_bit(); \
 164         } while (0)
 165
 166 #define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 167
 168 /*
 169  * Task priorities.
 170  * Note: if you change these, you must also change
 171  * the task initialization definitions below.
 172  */
 173 #define RPC_PRIORITY_LOW        (-1)
 174 #define RPC_PRIORITY_NORMAL     (0)
 175 #define RPC_PRIORITY_HIGH       (1)
 176 #define RPC_PRIORITY_PRIVILEGED (2)
 177 #define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
 178
 179 struct rpc_timer {
 180         struct timer_list timer;
 181         struct list_head list;
 182         unsigned long expires;
 183 };
 184
 185 /*
 186  * RPC synchronization objects
 187  */
 188 struct rpc_wait_queue {
 189         spinlock_t              lock;
 190         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 191         pid_t                   owner;                  /* process id of last task serviced */
 192         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 193         unsigned char           priority;               /* current priority */
 194         unsigned char           count;                  /* # task groups remaining serviced so far */
 195         unsigned char           nr;                     /* # tasks remaining for cookie */
 196         unsigned short          qlen;                   /* total # tasks waiting in queue */
 197         struct rpc_timer        timer_list;
 198 #ifdef RPC_DEBUG
 199         const char *            name;
 200 #endif
 201 };
 202
 203 /*
 204  * This is the # requests to send consecutively
 205  * from a single cookie.  The aim is to improve
 206  * performance of NFS operations such as read/write.
 207  */
 208 #define RPC_BATCH_COUNT                 16
 209 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 210
 211 /*
 212  * Function prototypes
 213  */
 214 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 215 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 216 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 217                                 const struct rpc_call_ops *ops);
 218 void            rpc_put_task(struct rpc_task *);
 219 void            rpc_exit_task(struct rpc_task *);
 220 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 221 void            rpc_killall_tasks(struct rpc_clnt *);
 222 void            rpc_execute(struct rpc_task *);
 223 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 224 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 225 void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 226 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 227                                         rpc_action action);
 228 void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 229                                         struct rpc_task *);
 230 void            rpc_wake_up(struct rpc_wait_queue *);
 231 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 232 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 233 int             rpc_queue_empty(struct rpc_wait_queue *);
 234 void            rpc_delay(struct rpc_task *, unsigned long);
 235 void *          rpc_malloc(struct rpc_task *, size_t);
 236 void            rpc_free(void *);
 237 int             rpciod_up(void);
 238 void            rpciod_down(void);
 239 int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 240 #ifdef RPC_DEBUG
 241 void            rpc_show_tasks(void);
 242 #endif
 243 int             rpc_init_mempool(void);
 244 void            rpc_destroy_mempool(void);
 245 extern struct workqueue_struct *rpciod_workqueue;
 246 void            rpc_prepare_task(struct rpc_task *task);
 247
 248 static inline void rpc_exit(struct rpc_task *task, int status)
 249 {
 250         task->tk_status = status;
 251         task->tk_action = rpc_exit_task;
 252 }
 253
 254 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 255 {
 256         return __rpc_wait_for_completion_task(task, NULL);
 257 }
 258
 259 static inline void rpc_task_set_priority(struct rpc_task *task, unsigned char prio)
 260 {
 261         task->tk_priority = prio - RPC_PRIORITY_LOW;
 262 }
 263
 264 static inline int rpc_task_has_priority(struct rpc_task *task, unsigned char prio)
 265 {
 266         return (task->tk_priority + RPC_PRIORITY_LOW == prio);
 267 }
 268
 269 #ifdef RPC_DEBUG
 270 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 271 {
 272         return ((q && q->name) ? q->name : "unknown");
 273 }
 274 #endif
 275
 276 #endif /* _LINUX_SUNRPC_SCHED_H_ */