include/linux/sunrpc/sched.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * linux/include/linux/sunrpc/sched.h
   4  *
   5  * Scheduling primitives for kernel Sun RPC.
   6  *
   7  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   8  */
   9
  10 #ifndef _LINUX_SUNRPC_SCHED_H_
  11 #define _LINUX_SUNRPC_SCHED_H_
  12
  13 #include <linux/timer.h>
  14 #include <linux/ktime.h>
  15 #include <linux/sunrpc/types.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/wait_bit.h>
  18 #include <linux/workqueue.h>
  19 #include <linux/sunrpc/xdr.h>
  20
  21 /*
  22  * This is the actual RPC procedure call info.
  23  */
  24 struct rpc_procinfo;
  25 struct rpc_message {
  26         const struct rpc_procinfo *rpc_proc;    /* Procedure information */
  27         void *                  rpc_argp;       /* Arguments */
  28         void *                  rpc_resp;       /* Result */
  29         const struct cred *     rpc_cred;       /* Credentials */
  30 };
  31
  32 struct rpc_call_ops;
  33 struct rpc_wait_queue;
  34 struct rpc_wait {
  35         struct list_head        list;           /* wait queue links */
  36         struct list_head        links;          /* Links to related tasks */
  37         struct list_head        timer_list;     /* Timer list */
  38 };
  39
  40 /*
  41  * This describes a timeout strategy
  42  */
  43 struct rpc_timeout {
  44         unsigned long           to_initval,             /* initial timeout */
  45                                 to_maxval,              /* max timeout */
  46                                 to_increment;           /* if !exponential */
  47         unsigned int            to_retries;             /* max # of retries */
  48         unsigned char           to_exponential;
  49 };
  50
  51 /*
  52  * This is the RPC task struct
  53  */
  54 struct rpc_task {
  55         atomic_t                tk_count;       /* Reference count */
  56         int                     tk_status;      /* result of last operation */
  57         struct list_head        tk_task;        /* global list of tasks */
  58
  59         /*
  60          * callback     to be executed after waking up
  61          * action       next procedure for async tasks
  62          */
  63         void                    (*tk_callback)(struct rpc_task *);
  64         void                    (*tk_action)(struct rpc_task *);
  65
  66         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  67         unsigned long           tk_runstate;    /* Task run status */
  68
  69         struct rpc_wait_queue   *tk_waitqueue;  /* RPC wait queue we're on */
  70         union {
  71                 struct work_struct      tk_work;        /* Async task work queue */
  72                 struct rpc_wait         tk_wait;        /* RPC wait */
  73         } u;
  74
  75         /*
  76          * RPC call state
  77          */
  78         struct rpc_message      tk_msg;         /* RPC call info */
  79         void *                  tk_calldata;    /* Caller private data */
  80         const struct rpc_call_ops *tk_ops;      /* Caller callbacks */
  81
  82         struct rpc_clnt *       tk_client;      /* RPC client */
  83         struct rpc_xprt *       tk_xprt;        /* Transport */
  84         struct rpc_cred *       tk_op_cred;     /* cred being operated on */
  85
  86         struct rpc_rqst *       tk_rqstp;       /* RPC request */
  87
  88         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  89                                                  * be any workqueue
  90                                                  */
  91         ktime_t                 tk_start;       /* RPC task init timestamp */
  92
  93         pid_t                   tk_owner;       /* Process id for batching tasks */
  94
  95         int                     tk_rpc_status;  /* Result of last RPC operation */
  96         unsigned short          tk_flags;       /* misc flags */
  97         unsigned short          tk_timeouts;    /* maj timeouts */
  98
  99 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 100         unsigned short          tk_pid;         /* debugging aid */
 101 #endif
 102         unsigned char           tk_priority : 2,/* Task priority */
 103                                 tk_garb_retry : 2,
 104                                 tk_cred_retry : 2;
 105 };
 106
 107 typedef void                    (*rpc_action)(struct rpc_task *);
 108
 109 struct rpc_call_ops {
 110         void (*rpc_call_prepare)(struct rpc_task *, void *);
 111         void (*rpc_call_done)(struct rpc_task *, void *);
 112         void (*rpc_count_stats)(struct rpc_task *, void *);
 113         void (*rpc_release)(void *);
 114 };
 115
 116 struct rpc_task_setup {
 117         struct rpc_task *task;
 118         struct rpc_clnt *rpc_client;
 119         struct rpc_xprt *rpc_xprt;
 120         struct rpc_cred *rpc_op_cred;   /* credential being operated on */
 121         const struct rpc_message *rpc_message;
 122         const struct rpc_call_ops *callback_ops;
 123         void *callback_data;
 124         struct workqueue_struct *workqueue;
 125         unsigned short flags;
 126         signed char priority;
 127 };
 128
 129 /*
 130  * RPC task flags
 131  */
 132 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 133 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 134 #define RPC_TASK_MOVEABLE       0x0004          /* nfs4.1+ rpc tasks */
 135 #define RPC_TASK_NULLCREDS      0x0010          /* Use AUTH_NULL credential */
 136 #define RPC_CALL_MAJORSEEN      0x0020          /* major timeout seen */
 137 #define RPC_TASK_DYNAMIC        0x0080          /* task was kmalloc'ed */
 138 #define RPC_TASK_NO_ROUND_ROBIN 0x0100          /* send requests on "main" xprt */
 139 #define RPC_TASK_SOFT           0x0200          /* Use soft timeouts */
 140 #define RPC_TASK_SOFTCONN       0x0400          /* Fail if can't connect */
 141 #define RPC_TASK_SENT           0x0800          /* message was sent */
 142 #define RPC_TASK_TIMEOUT        0x1000          /* fail with ETIMEDOUT on timeout */
 143 #define RPC_TASK_NOCONNECT      0x2000          /* return ENOTCONN if not connected */
 144 #define RPC_TASK_NO_RETRANS_TIMEOUT     0x4000          /* wait forever for a reply */
 145 #define RPC_TASK_CRED_NOREF     0x8000          /* No refcount on the credential */
 146
 147 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 148 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 149 #define RPC_IS_SOFT(t)          ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
 150 #define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 151 #define RPC_WAS_SENT(t)         ((t)->tk_flags & RPC_TASK_SENT)
 152 #define RPC_IS_MOVEABLE(t)      ((t)->tk_flags & RPC_TASK_MOVEABLE)
 153
 154 enum {
 155         RPC_TASK_RUNNING,
 156         RPC_TASK_QUEUED,
 157         RPC_TASK_ACTIVE,
 158         RPC_TASK_NEED_XMIT,
 159         RPC_TASK_NEED_RECV,
 160         RPC_TASK_MSG_PIN_WAIT,
 161         RPC_TASK_SIGNALLED,
 162 };
 163
 164 #define rpc_test_and_set_running(t) \
 165                                 test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 166 #define rpc_clear_running(t)    clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 167
 168 #define RPC_IS_QUEUED(t)        test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 169 #define rpc_set_queued(t)       set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 170 #define rpc_clear_queued(t)     clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
 171
 172 #define RPC_IS_ACTIVATED(t)     test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
 173
 174 #define RPC_SIGNALLED(t)        test_bit(RPC_TASK_SIGNALLED, &(t)->tk_runstate)
 175
 176 /*
 177  * Task priorities.
 178  * Note: if you change these, you must also change
 179  * the task initialization definitions below.
 180  */
 181 #define RPC_PRIORITY_LOW        (-1)
 182 #define RPC_PRIORITY_NORMAL     (0)
 183 #define RPC_PRIORITY_HIGH       (1)
 184 #define RPC_PRIORITY_PRIVILEGED (2)
 185 #define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
 186
 187 struct rpc_timer {
 188         struct list_head list;
 189         unsigned long expires;
 190         struct delayed_work dwork;
 191 };
 192
 193 /*
 194  * RPC synchronization objects
 195  */
 196 struct rpc_wait_queue {
 197         spinlock_t              lock;
 198         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
 199         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
 200         unsigned char           priority;               /* current priority */
 201         unsigned char           nr;                     /* # tasks remaining for cookie */
 202         unsigned int            qlen;                   /* total # tasks waiting in queue */
 203         struct rpc_timer        timer_list;
 204 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 205         const char *            name;
 206 #endif
 207 };
 208
 209 /*
 210  * This is the # requests to send consecutively
 211  * from a single cookie.  The aim is to improve
 212  * performance of NFS operations such as read/write.
 213  */
 214 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 215
 216 /*
 217  * Function prototypes
 218  */
 219 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 220 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 221 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 222                 struct rpc_timeout *timeout);
 223 void            rpc_put_task(struct rpc_task *);
 224 void            rpc_put_task_async(struct rpc_task *);
 225 bool            rpc_task_set_rpc_status(struct rpc_task *task, int rpc_status);
 226 void            rpc_task_try_cancel(struct rpc_task *task, int error);
 227 void            rpc_signal_task(struct rpc_task *);
 228 void            rpc_exit_task(struct rpc_task *);
 229 void            rpc_exit(struct rpc_task *, int);
 230 void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 231 void            rpc_killall_tasks(struct rpc_clnt *);
 232 unsigned long   rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
 233                                  bool (*fnmatch)(const struct rpc_task *,
 234                                                  const void *),
 235                                  const void *data);
 236 void            rpc_execute(struct rpc_task *);
 237 void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 238 void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 239 void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 240 unsigned long   rpc_task_timeout(const struct rpc_task *task);
 241 void            rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
 242                                         struct rpc_task *task,
 243                                         rpc_action action,
 244                                         unsigned long timeout);
 245 void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 246                                         rpc_action action);
 247 void            rpc_sleep_on_priority_timeout(struct rpc_wait_queue *queue,
 248                                         struct rpc_task *task,
 249                                         unsigned long timeout,
 250                                         int priority);
 251 void            rpc_sleep_on_priority(struct rpc_wait_queue *,
 252                                         struct rpc_task *,
 253                                         int priority);
 254 void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 255                                         struct rpc_task *);
 256 void            rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
 257                                                    struct rpc_task *,
 258                                                    int);
 259 void            rpc_wake_up(struct rpc_wait_queue *);
 260 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 261 struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
 262                                         struct rpc_wait_queue *,
 263                                         bool (*)(struct rpc_task *, void *),
 264                                         void *);
 265 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
 266                                         bool (*)(struct rpc_task *, void *),
 267                                         void *);
 268 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 269 void            rpc_delay(struct rpc_task *, unsigned long);
 270 int             rpc_malloc(struct rpc_task *);
 271 void            rpc_free(struct rpc_task *);
 272 int             rpciod_up(void);
 273 void            rpciod_down(void);
 274 int             rpc_wait_for_completion_task(struct rpc_task *task);
 275 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 276 struct net;
 277 void            rpc_show_tasks(struct net *);
 278 #endif
 279 int             rpc_init_mempool(void);
 280 void            rpc_destroy_mempool(void);
 281 extern struct workqueue_struct *rpciod_workqueue;
 282 extern struct workqueue_struct *xprtiod_workqueue;
 283 void            rpc_prepare_task(struct rpc_task *task);
 284 gfp_t           rpc_task_gfp_mask(void);
 285
 286 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 287 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
 288 {
 289         return ((q && q->name) ? q->name : "unknown");
 290 }
 291
 292 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 293                 const char *name)
 294 {
 295         q->name = name;
 296 }
 297 #else
 298 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 299                 const char *name)
 300 {
 301 }
 302 #endif
 303
 304 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
 305 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
 306 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
 307 #else
 308 static inline int
 309 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
 310 {
 311         return -EINVAL;
 312 }
 313
 314 static inline void
 315 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
 316 {
 317 }
 318 #endif /* CONFIG_SUNRPC_SWAP */
 319
 320 #endif /* _LINUX_SUNRPC_SCHED_H_ */