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
 134 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 135 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 136 #define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 137 #define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 138 #define RPC_IS_SOFT(t)          ((t)->tk_flags & RPC_TASK_SOFT)
 139
 140 #define RPC_TASK_RUNNING        0
 141 #define RPC_TASK_QUEUED         1
 142 #define RPC_TASK_ACTIVE         2
 143
 144 #define RPC_IS_RUNNING(t)       test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 145 #define rpc_set_running(t)      set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 146 #define rpc_test_and_set_running(t) \
 147                                 test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 148 #define rpc_clear_running(t)    \
 149         do { \
 150                 smp_mb__before_clear_bit(); \
 151                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 152                 smp_mb__after_clear_bit(); \
 153         } while (0)
 154
 155 #define RPC_IS_QUEUED(t)        test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 156 #define rpc_set_queued(t)       set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 157 #define rpc_clear_queued(t)     \
 158         do { \
 159                 smp_mb__before_clear_bit(); \
 160                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 161                 smp_mb__after_clear_bit(); \
 162         } while (0)
 163
 164 #define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 165
 166 /*
 167  * Task priorities.
 168  * Note: if you change these, you must also change
 169  * the task initialization definitions below.
 170  */
 171 #define RPC_PRIORITY_LOW        (-1)
 172 #define RPC_PRIORITY_NORMAL     (0)
 173 #define RPC_PRIORITY_HIGH       (1)
 174 #define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_HIGH - RPC_PRIORITY_LOW)
 175
 176 struct rpc_timer {
 177         struct timer_list timer;
 178         struct list_head list;
 179         unsigned long expires;
 180 };
 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         pid_t                   owner;                  /* process id 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         unsigned short          qlen;                   /* total # tasks waiting in queue */
 194         struct rpc_timer        timer_list;
 195 #ifdef RPC_DEBUG
 196         const char *            name;
 197 #endif
 198 };
 199
 200 /*
 201  * This is the # requests to send consecutively
 202  * from a single cookie.  The aim is to improve
 203  * performance of NFS operations such as read/write.
 204  */
 205 #define RPC_BATCH_COUNT                 16
 206 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 207
 208 /*
 209  * Function prototypes
 210  */
 211 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 212 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 213 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 214                                 const struct rpc_call_ops *ops);
 215 void            rpc_put_task(struct rpc_task *);
 216 void            rpc_exit_task(struct rpc_task *);
 217 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 218 void            rpc_killall_tasks(struct rpc_clnt *);
 219 void            rpc_execute(struct rpc_task *);
 220 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 221 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 222 void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 223 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 224                                         rpc_action action);
 225 void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 226                                         struct rpc_task *);
 227 void            rpc_wake_up(struct rpc_wait_queue *);
 228 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 229 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 230 void            rpc_delay(struct rpc_task *, unsigned long);
 231 void *          rpc_malloc(struct rpc_task *, size_t);
 232 void            rpc_free(void *);
 233 int             rpciod_up(void);
 234 void            rpciod_down(void);
 235 int             __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
 236 #ifdef RPC_DEBUG
 237 void            rpc_show_tasks(void);
 238 #endif
 239 int             rpc_init_mempool(void);
 240 void            rpc_destroy_mempool(void);
 241 extern struct workqueue_struct *rpciod_workqueue;
 242 void            rpc_prepare_task(struct rpc_task *task);
 243
 244 static inline void rpc_exit(struct rpc_task *task, int status)
 245 {
 246         task->tk_status = status;
 247         task->tk_action = rpc_exit_task;
 248 }
 249
 250 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 251 {
 252         return __rpc_wait_for_completion_task(task, NULL);
 253 }
 254
 255 #ifdef RPC_DEBUG
 256 static inline const char * rpc_qname(struct rpc_wait_queue *q)
 257 {
 258         return ((q && q->name) ? q->name : "unknown");
 259 }
 260 #endif
 261
 262 #endif /* _LINUX_SUNRPC_SCHED_H_ */