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_wait_queue;
  31 struct rpc_wait {
  32         struct list_head        list;           /* wait queue links */
  33         struct list_head        links;          /* Links to related tasks */
  34         wait_queue_head_t       waitq;          /* sync: sleep on this q */
  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         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         int                     tk_status;      /* result of last operation */
  49
  50         /*
  51          * RPC call state
  52          */
  53         struct rpc_message      tk_msg;         /* RPC call info */
  54         __u32 *                 tk_buffer;      /* XDR buffer */
  55         size_t                  tk_bufsize;
  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          * exit         exit async task and report to caller
  66          */
  67         void                    (*tk_timeout_fn)(struct rpc_task *);
  68         void                    (*tk_callback)(struct rpc_task *);
  69         void                    (*tk_action)(struct rpc_task *);
  70         void                    (*tk_exit)(struct rpc_task *);
  71         void                    (*tk_release)(struct rpc_task *);
  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_active   : 1;/* Task has been activated */
  83         unsigned char           tk_priority : 2;/* Task priority */
  84         unsigned long           tk_runstate;    /* Task run status */
  85         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  86                                                  * be any workqueue
  87                                                  */
  88         union {
  89                 struct work_struct      tk_work;        /* Async task work queue */
  90                 struct rpc_wait         tk_wait;        /* RPC wait */
  91         } u;
  92 #ifdef RPC_DEBUG
  93         unsigned short          tk_pid;         /* debugging aid */
  94 #endif
  95 };
  96 #define tk_auth                 tk_client->cl_auth
  97 #define tk_xprt                 tk_client->cl_xprt
  98
  99 /* support walking a list of tasks on a wait queue */
 100 #define task_for_each(task, pos, head) \
 101         list_for_each(pos, head) \
 102                 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
 103
 104 #define task_for_first(task, head) \
 105         if (!list_empty(head) &&  \
 106             ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
 107
 108 /* .. and walking list of all tasks */
 109 #define alltask_for_each(task, pos, head) \
 110         list_for_each(pos, head) \
 111                 if ((task=list_entry(pos, struct rpc_task, tk_task)),1)
 112
 113 typedef void                    (*rpc_action)(struct rpc_task *);
 114
 115 /*
 116  * RPC task flags
 117  */
 118 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 119 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 120 #define RPC_TASK_CHILD          0x0008          /* is child of other task */
 121 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 122 #define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 123 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 124 #define RPC_TASK_KILLED         0x0100          /* task was killed */
 125 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 126 #define RPC_TASK_NOINTR         0x0400          /* uninterruptible task */
 127
 128 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 129 #define RPC_IS_CHILD(t)         ((t)->tk_flags & RPC_TASK_CHILD)
 130 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 131 #define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 132 #define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 133 #define RPC_IS_ACTIVATED(t)     ((t)->tk_active)
 134 #define RPC_DO_CALLBACK(t)      ((t)->tk_callback != NULL)
 135 #define RPC_IS_SOFT(t)          ((t)->tk_flags & RPC_TASK_SOFT)
 136 #define RPC_TASK_UNINTERRUPTIBLE(t) ((t)->tk_flags & RPC_TASK_NOINTR)
 137
 138 #define RPC_TASK_RUNNING        0
 139 #define RPC_TASK_QUEUED         1
 140 #define RPC_TASK_WAKEUP         2
 141 #define RPC_TASK_HAS_TIMER      3
 142
 143 #define RPC_IS_RUNNING(t)       (test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 144 #define rpc_set_running(t)      (set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 145 #define rpc_test_and_set_running(t) \
 146                                 (test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate))
 147 #define rpc_clear_running(t)    \
 148         do { \
 149                 smp_mb__before_clear_bit(); \
 150                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 151                 smp_mb__after_clear_bit(); \
 152         } while (0)
 153
 154 #define RPC_IS_QUEUED(t)        (test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate))
 155 #define rpc_set_queued(t)       (set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate))
 156 #define rpc_clear_queued(t)     \
 157         do { \
 158                 smp_mb__before_clear_bit(); \
 159                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 160                 smp_mb__after_clear_bit(); \
 161         } while (0)
 162
 163 #define rpc_start_wakeup(t) \
 164         (test_and_set_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate) == 0)
 165 #define rpc_finish_wakeup(t) \
 166         do { \
 167                 smp_mb__before_clear_bit(); \
 168                 clear_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate); \
 169                 smp_mb__after_clear_bit(); \
 170         } while (0)
 171
 172 /*
 173  * Task priorities.
 174  * Note: if you change these, you must also change
 175  * the task initialization definitions below.
 176  */
 177 #define RPC_PRIORITY_LOW        0
 178 #define RPC_PRIORITY_NORMAL     1
 179 #define RPC_PRIORITY_HIGH       2
 180 #define RPC_NR_PRIORITY         (RPC_PRIORITY_HIGH+1)
 181
 182 /*
 183  * RPC synchronization objects
 184  */
 185 struct rpc_wait_queue {
 186         spinlock_t              lock;
 187         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 188         unsigned long           cookie;                 /* cookie of last task serviced */
 189         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 190         unsigned char           priority;               /* current priority */
 191         unsigned char           count;                  /* # task groups remaining serviced so far */
 192         unsigned char           nr;                     /* # tasks remaining for cookie */
 193 #ifdef RPC_DEBUG
 194         const char *            name;
 195 #endif
 196 };
 197
 198 /*
 199  * This is the # requests to send consecutively
 200  * from a single cookie.  The aim is to improve
 201  * performance of NFS operations such as read/write.
 202  */
 203 #define RPC_BATCH_COUNT                 16
 204
 205 #ifndef RPC_DEBUG
 206 # define RPC_WAITQ_INIT(var,qname) { \
 207                 .lock = SPIN_LOCK_UNLOCKED, \
 208                 .tasks = { \
 209                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 210                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 211                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 212                 }, \
 213         }
 214 #else
 215 # define RPC_WAITQ_INIT(var,qname) { \
 216                 .lock = SPIN_LOCK_UNLOCKED, \
 217                 .tasks = { \
 218                         [0] = LIST_HEAD_INIT(var.tasks[0]), \
 219                         [1] = LIST_HEAD_INIT(var.tasks[1]), \
 220                         [2] = LIST_HEAD_INIT(var.tasks[2]), \
 221                 }, \
 222                 .name = qname, \
 223         }
 224 #endif
 225 # define RPC_WAITQ(var,qname)      struct rpc_wait_queue var = RPC_WAITQ_INIT(var,qname)
 226
 227 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 228
 229 /*
 230  * Function prototypes
 231  */
 232 struct rpc_task *rpc_new_task(struct rpc_clnt *, rpc_action, int flags);
 233 struct rpc_task *rpc_new_child(struct rpc_clnt *, struct rpc_task *parent);
 234 void            rpc_init_task(struct rpc_task *, struct rpc_clnt *,
 235                                         rpc_action exitfunc, int flags);
 236 void            rpc_release_task(struct rpc_task *);
 237 void            rpc_killall_tasks(struct rpc_clnt *);
 238 int             rpc_execute(struct rpc_task *);
 239 void            rpc_run_child(struct rpc_task *parent, struct rpc_task *child,
 240                                         rpc_action action);
 241 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 242 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 243 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 244                                         rpc_action action, rpc_action timer);
 245 void            rpc_wake_up_task(struct rpc_task *);
 246 void            rpc_wake_up(struct rpc_wait_queue *);
 247 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 248 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 249 void            rpc_delay(struct rpc_task *, unsigned long);
 250 void *          rpc_malloc(struct rpc_task *, size_t);
 251 int             rpciod_up(void);
 252 void            rpciod_down(void);
 253 void            rpciod_wake_up(void);
 254 #ifdef RPC_DEBUG
 255 void            rpc_show_tasks(void);
 256 #endif
 257 int             rpc_init_mempool(void);
 258 void            rpc_destroy_mempool(void);
 259
 260 static inline void rpc_exit(struct rpc_task *task, int status)
 261 {
 262         task->tk_status = status;
 263         task->tk_action = NULL;
 264 }
 265
 266 #ifdef RPC_DEBUG
 267 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 268 {
 269         return ((q && q->name) ? q->name : "unknown");
 270 }
 271 #endif
 272
 273 #endif /* _LINUX_SUNRPC_SCHED_H_ */