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         struct rpc_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         unsigned long           expires;
  39 };
  40
  41 /*
  42  * This is the RPC task struct
  43  */
  44 struct rpc_task {
  45         atomic_t                tk_count;       /* Reference count */
  46         int                     tk_status;      /* result of last operation */
  47         struct list_head        tk_task;        /* global list of tasks */
  48
  49         /*
  50          * callback     to be executed after waking up
  51          * action       next procedure for async tasks
  52          */
  53         void                    (*tk_callback)(struct rpc_task *);
  54         void                    (*tk_action)(struct rpc_task *);
  55
  56         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
  57         unsigned long           tk_runstate;    /* Task run status */
  58
  59         struct rpc_wait_queue   *tk_waitqueue;  /* RPC wait queue we're on */
  60         union {
  61                 struct work_struct      tk_work;        /* Async task work queue */
  62                 struct rpc_wait         tk_wait;        /* RPC wait */
  63         } u;
  64
  65         /*
  66          * RPC call state
  67          */
  68         struct rpc_message      tk_msg;         /* RPC call info */
  69         void *                  tk_calldata;    /* Caller private data */
  70         const struct rpc_call_ops *tk_ops;      /* Caller callbacks */
  71
  72         struct rpc_clnt *       tk_client;      /* RPC client */
  73         struct rpc_xprt *       tk_xprt;        /* Transport */
  74
  75         struct rpc_rqst *       tk_rqstp;       /* RPC request */
  76
  77         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
  78                                                  * be any workqueue
  79                                                  */
  80         ktime_t                 tk_start;       /* RPC task init timestamp */
  81
  82         pid_t                   tk_owner;       /* Process id for batching tasks */
  83         unsigned short          tk_flags;       /* misc flags */
  84         unsigned short          tk_timeouts;    /* maj timeouts */
  85
  86 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
  87         unsigned short          tk_pid;         /* debugging aid */
  88 #endif
  89         unsigned char           tk_priority : 2,/* Task priority */
  90                                 tk_garb_retry : 2,
  91                                 tk_cred_retry : 2,
  92                                 tk_rebind_retry : 2;
  93 };
  94
  95 typedef void                    (*rpc_action)(struct rpc_task *);
  96
  97 struct rpc_call_ops {
  98         void (*rpc_call_prepare)(struct rpc_task *, void *);
  99         void (*rpc_call_done)(struct rpc_task *, void *);
 100         void (*rpc_count_stats)(struct rpc_task *, void *);
 101         void (*rpc_release)(void *);
 102 };
 103
 104 struct rpc_task_setup {
 105         struct rpc_task *task;
 106         struct rpc_clnt *rpc_client;
 107         struct rpc_xprt *rpc_xprt;
 108         const struct rpc_message *rpc_message;
 109         const struct rpc_call_ops *callback_ops;
 110         void *callback_data;
 111         struct workqueue_struct *workqueue;
 112         unsigned short flags;
 113         signed char priority;
 114 };
 115
 116 /*
 117  * RPC task flags
 118  */
 119 #define RPC_TASK_ASYNC          0x0001          /* is an async task */
 120 #define RPC_TASK_SWAPPER        0x0002          /* is swapping in/out */
 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_SOFTCONN       0x0400          /* Fail if can't connect */
 127 #define RPC_TASK_SENT           0x0800          /* message was sent */
 128 #define RPC_TASK_TIMEOUT        0x1000          /* fail with ETIMEDOUT on timeout */
 129 #define RPC_TASK_NOCONNECT      0x2000          /* return ENOTCONN if not connected */
 130 #define RPC_TASK_NO_RETRANS_TIMEOUT     0x4000          /* wait forever for a reply */
 131
 132 #define RPC_IS_ASYNC(t)         ((t)->tk_flags & RPC_TASK_ASYNC)
 133 #define RPC_IS_SWAPPER(t)       ((t)->tk_flags & RPC_TASK_SWAPPER)
 134 #define RPC_DO_ROOTOVERRIDE(t)  ((t)->tk_flags & RPC_TASK_ROOTCREDS)
 135 #define RPC_ASSASSINATED(t)     ((t)->tk_flags & RPC_TASK_KILLED)
 136 #define RPC_IS_SOFT(t)          ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
 137 #define RPC_IS_SOFTCONN(t)      ((t)->tk_flags & RPC_TASK_SOFTCONN)
 138 #define RPC_WAS_SENT(t)         ((t)->tk_flags & RPC_TASK_SENT)
 139
 140 #define RPC_TASK_RUNNING        0
 141 #define RPC_TASK_QUEUED         1
 142 #define RPC_TASK_ACTIVE         2
 143 #define RPC_TASK_MSG_RECV       3
 144 #define RPC_TASK_MSG_RECV_WAIT  4
 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_atomic(); \
 153                 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
 154                 smp_mb__after_atomic(); \
 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_atomic(); \
 162                 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
 163                 smp_mb__after_atomic(); \
 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           nr;                     /* # tasks remaining for cookie */
 195         unsigned short          qlen;                   /* total # tasks waiting in queue */
 196         struct rpc_timer        timer_list;
 197 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 198         const char *            name;
 199 #endif
 200 };
 201
 202 /*
 203  * This is the # requests to send consecutively
 204  * from a single cookie.  The aim is to improve
 205  * performance of NFS operations such as read/write.
 206  */
 207 #define RPC_BATCH_COUNT                 16
 208 #define RPC_IS_PRIORITY(q)              ((q)->maxpriority > 0)
 209
 210 /*
 211  * Function prototypes
 212  */
 213 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 214 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 215 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
 216 void            rpc_put_task(struct rpc_task *);
 217 void            rpc_put_task_async(struct rpc_task *);
 218 void            rpc_exit_task(struct rpc_task *);
 219 void            rpc_exit(struct rpc_task *, int);
 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_sleep_on_priority(struct rpc_wait_queue *,
 229                                         struct rpc_task *,
 230                                         rpc_action action,
 231                                         int priority);
 232 void rpc_wake_up_queued_task_on_wq(struct workqueue_struct *wq,
 233                 struct rpc_wait_queue *queue,
 234                 struct rpc_task *task);
 235 void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 236                                         struct rpc_task *);
 237 void            rpc_wake_up(struct rpc_wait_queue *);
 238 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 239 struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
 240                                         struct rpc_wait_queue *,
 241                                         bool (*)(struct rpc_task *, void *),
 242                                         void *);
 243 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
 244                                         bool (*)(struct rpc_task *, void *),
 245                                         void *);
 246 void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 247 void            rpc_delay(struct rpc_task *, unsigned long);
 248 int             rpc_malloc(struct rpc_task *);
 249 void            rpc_free(struct rpc_task *);
 250 int             rpciod_up(void);
 251 void            rpciod_down(void);
 252 int             __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
 253 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 254 struct net;
 255 void            rpc_show_tasks(struct net *);
 256 #endif
 257 int             rpc_init_mempool(void);
 258 void            rpc_destroy_mempool(void);
 259 extern struct workqueue_struct *rpciod_workqueue;
 260 extern struct workqueue_struct *xprtiod_workqueue;
 261 void            rpc_prepare_task(struct rpc_task *task);
 262
 263 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
 264 {
 265         return __rpc_wait_for_completion_task(task, NULL);
 266 }
 267
 268 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
 269 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
 270 {
 271         return ((q && q->name) ? q->name : "unknown");
 272 }
 273
 274 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 275                 const char *name)
 276 {
 277         q->name = name;
 278 }
 279 #else
 280 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 281                 const char *name)
 282 {
 283 }
 284 #endif
 285
 286 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
 287 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
 288 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
 289 #else
 290 static inline int
 291 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
 292 {
 293         return -EINVAL;
 294 }
 295
 296 static inline void
 297 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
 298 {
 299 }
 300 #endif /* CONFIG_SUNRPC_SWAP */
 301
 302 #endif /* _LINUX_SUNRPC_SCHED_H_ */