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         int                     tk_status;      /* result of last operation */
  46         struct list_head        tk_task;        /* global list of tasks */
  47
  48         /*
  49          * callback     to be executed after waking up
  50          * action       next procedure for async tasks
  51          */
  52         void                    (*tk_callback)(struct rpc_task *);
  53         void                    (*tk_action)(struct rpc_task *);
  54
  55         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  56         unsigned long           tk_runstate;    /* Task run status */
  57
  58         struct rpc_wait_queue   *tk_waitqueue;  /* RPC wait queue we're on */
  59         union {
  60                 struct work_struct      tk_work;        /* Async task work queue */
  61                 struct rpc_wait         tk_wait;        /* RPC wait */
  62         } u;
  63
  64         /*
  65          * RPC call state
  66          */
  67         struct rpc_message      tk_msg;         /* RPC call info */
  68         void *                  tk_calldata;    /* Caller private data */
  69         const struct rpc_call_ops *tk_ops;      /* Caller callbacks */
  70
  71         struct rpc_clnt *       tk_client;      /* RPC client */
  72         struct rpc_xprt *       tk_xprt;        /* Transport */
  73
  74         struct rpc_rqst *       tk_rqstp;       /* RPC request */
  75
  76         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  77                                                  * be any workqueue
  78                                                  */
  79         ktime_t                 tk_start;       /* RPC task init timestamp */
  80
  81         pid_t                   tk_owner;       /* Process id for batching tasks */
  82         unsigned short          tk_flags;       /* misc flags */
  83         unsigned short          tk_timeouts;    /* maj timeouts */
  84
  85 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
  86         unsigned short          tk_pid;         /* debugging aid */
  87 #endif
  88         unsigned char           tk_priority : 2,/* Task priority */
  89                                 tk_garb_retry : 2,
  90                                 tk_cred_retry : 2,
  91                                 tk_rebind_retry : 2;
  92 };
  93
  94 typedef void                    (*rpc_action)(struct rpc_task *);
  95
  96 struct rpc_call_ops {
  97         void (*rpc_call_prepare)(struct rpc_task *, void *);
  98         void (*rpc_call_done)(struct rpc_task *, void *);
  99         void (*rpc_count_stats)(struct rpc_task *, void *);
 100         void (*rpc_release)(void *);
 101 };
 102
 103 struct rpc_task_setup {
 104         struct rpc_task *task;
 105         struct rpc_clnt *rpc_client;
 106         const struct rpc_message *rpc_message;
 107         const struct rpc_call_ops *callback_ops;
 108         void *callback_data;
 109         struct workqueue_struct *workqueue;
 110         unsigned short flags;
 111         signed char priority;
 112 };
 113
 114 /*
 115  * RPC task flags
 116  */
 117 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 118 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 119 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 120 #define RPC_TASK_ROOTCREDS      0x0040          /* force root creds */
 121 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 122 #define RPC_TASK_KILLED         0x0100          /* task was killed */
 123 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 124 #define RPC_TASK_SOFTCONN       0x0400          /* Fail if can't connect */
 125 #define RPC_TASK_SENT           0x0800          /* message was sent */
 126 #define RPC_TASK_TIMEOUT        0x1000          /* fail with ETIMEDOUT on timeout */
 127 #define RPC_TASK_NOCONNECT      0x2000          /* return ENOTCONN if not connected */
 128 #define RPC_TASK_NO_RETRANS_TIMEOUT     0x4000          /* wait forever for a reply */
 129
 130 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 131 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 132 #define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 133 #define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 134 #define RPC_IS_SOFT(t)          ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
 135 #define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 136 #define RPC_WAS_SENT(t)         ((t)->tk_flags & RPC_TASK_SENT)
 137
 138 #define RPC_TASK_RUNNING        0
 139 #define RPC_TASK_QUEUED         1
 140 #define RPC_TASK_ACTIVE         2
 141
 142 #define RPC_IS_RUNNING(t)       test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 143 #define rpc_set_running(t)      set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 144 #define rpc_test_and_set_running(t) \
 145                                 test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 146 #define rpc_clear_running(t)    \
 147         do { \
 148                 smp_mb__before_atomic(); \
 149                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 150                 smp_mb__after_atomic(); \
 151         } while (0)
 152
 153 #define RPC_IS_QUEUED(t)        test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 154 #define rpc_set_queued(t)       set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 155 #define rpc_clear_queued(t)     \
 156         do { \
 157                 smp_mb__before_atomic(); \
 158                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 159                 smp_mb__after_atomic(); \
 160         } while (0)
 161
 162 #define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 163
 164 /*
 165  * Task priorities.
 166  * Note: if you change these, you must also change
 167  * the task initialization definitions below.
 168  */
 169 #define RPC_PRIORITY_LOW        (-1)
 170 #define RPC_PRIORITY_NORMAL     (0)
 171 #define RPC_PRIORITY_HIGH       (1)
 172 #define RPC_PRIORITY_PRIVILEGED (2)
 173 #define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
 174
 175 struct rpc_timer {
 176         struct timer_list timer;
 177         struct list_head list;
 178         unsigned long expires;
 179 };
 180
 181 /*
 182  * RPC synchronization objects
 183  */
 184 struct rpc_wait_queue {
 185         spinlock_t              lock;
 186         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 187         pid_t                   owner;                  /* process id of last task serviced */
 188         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 189         unsigned char           priority;               /* current priority */
 190         unsigned char           nr;                     /* # tasks remaining for cookie */
 191         unsigned short          qlen;                   /* total # tasks waiting in queue */
 192         struct rpc_timer        timer_list;
 193 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 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 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 205
 206 /*
 207  * Function prototypes
 208  */
 209 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 210 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 211 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
 212 void            rpc_put_task(struct rpc_task *);
 213 void            rpc_put_task_async(struct rpc_task *);
 214 void            rpc_exit_task(struct rpc_task *);
 215 void            rpc_exit(struct rpc_task *, int);
 216 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 217 void            rpc_killall_tasks(struct rpc_clnt *);
 218 void            rpc_execute(struct rpc_task *);
 219 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 220 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 221 void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 222 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 223                                         rpc_action action);
 224 void            rpc_sleep_on_priority(struct rpc_wait_queue *,
 225                                         struct rpc_task *,
 226                                         rpc_action action,
 227                                         int priority);
 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 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
 233                                         bool (*)(struct rpc_task *, void *),
 234                                         void *);
 235 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 236 void            rpc_delay(struct rpc_task *, unsigned long);
 237 void *          rpc_malloc(struct rpc_task *, size_t);
 238 void            rpc_free(void *);
 239 int             rpciod_up(void);
 240 void            rpciod_down(void);
 241 int             __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
 242 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 243 struct net;
 244 void            rpc_show_tasks(struct net *);
 245 #endif
 246 int             rpc_init_mempool(void);
 247 void            rpc_destroy_mempool(void);
 248 extern struct workqueue_struct *rpciod_workqueue;
 249 void            rpc_prepare_task(struct rpc_task *task);
 250
 251 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 252 {
 253         return __rpc_wait_for_completion_task(task, NULL);
 254 }
 255
 256 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 257 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
 258 {
 259         return ((q && q->name) ? q->name : "unknown");
 260 }
 261
 262 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 263                 const char *name)
 264 {
 265         q->name = name;
 266 }
 267 #else
 268 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 269                 const char *name)
 270 {
 271 }
 272 #endif
 273
 274 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
 275 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
 276 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
 277 #else
 278 static inline int
 279 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
 280 {
 281         return -EINVAL;
 282 }
 283
 284 static inline void
 285 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
 286 {
 287 }
 288 #endif /* CONFIG_SUNRPC_SWAP */
 289
 290 #endif /* _LINUX_SUNRPC_SCHED_H_ */