LXR linux/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 */
  24struct rpc_procinfo;
  25struct 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
  32struct rpc_call_ops;
  33struct rpc_wait_queue;
  34struct 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 */
  44struct 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
  95typedef void                    (*rpc_action)(struct rpc_task *);
  96
  97struct 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
 104struct 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
 179struct rpc_timer {
 180        struct timer_list timer;
 181        struct list_head list;
 182        unsigned long expires;
 183};
 184
 185/*
 186 * RPC synchronization objects
 187 */
 188struct 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 */
 213struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
 214struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
 215struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
 216void            rpc_put_task(struct rpc_task *);
 217void            rpc_put_task_async(struct rpc_task *);
 218void            rpc_exit_task(struct rpc_task *);
 219void            rpc_exit(struct rpc_task *, int);
 220void            rpc_release_calldata(const struct rpc_call_ops *, void *);
 221void            rpc_killall_tasks(struct rpc_clnt *);
 222void            rpc_execute(struct rpc_task *);
 223void            rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 224void            rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 225void            rpc_destroy_wait_queue(struct rpc_wait_queue *);
 226void            rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
 227                                        rpc_action action);
 228void            rpc_sleep_on_priority(struct rpc_wait_queue *,
 229                                        struct rpc_task *,
 230                                        rpc_action action,
 231                                        int priority);
 232void rpc_wake_up_queued_task_on_wq(struct workqueue_struct *wq,
 233                struct rpc_wait_queue *queue,
 234                struct rpc_task *task);
 235void            rpc_wake_up_queued_task(struct rpc_wait_queue *,
 236                                        struct rpc_task *);
 237void            rpc_wake_up(struct rpc_wait_queue *);
 238struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
 239struct 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 *);
 243struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
 244                                        bool (*)(struct rpc_task *, void *),
 245                                        void *);
 246void            rpc_wake_up_status(struct rpc_wait_queue *, int);
 247void            rpc_delay(struct rpc_task *, unsigned long);
 248int             rpc_malloc(struct rpc_task *);
 249void            rpc_free(struct rpc_task *);
 250int             rpciod_up(void);
 251void            rpciod_down(void);
 252int             __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
 253#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 254struct net;
 255void            rpc_show_tasks(struct net *);
 256#endif
 257int             rpc_init_mempool(void);
 258void            rpc_destroy_mempool(void);
 259extern struct workqueue_struct *rpciod_workqueue;
 260extern struct workqueue_struct *xprtiod_workqueue;
 261void            rpc_prepare_task(struct rpc_task *task);
 262
 263static 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)
 269static inline const char * rpc_qname(const struct rpc_wait_queue *q)
 270{
 271        return ((q && q->name) ? q->name : "unknown");
 272}
 273
 274static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
 275                const char *name)
 276{
 277        q->name = name;
 278}
 279#else
 280static 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)
 287int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
 288void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
 289#else
 290static inline int
 291rpc_clnt_swap_activate(struct rpc_clnt *clnt)
 292{
 293        return -EINVAL;
 294}
 295
 296static inline void
 297rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
 298{
 299}
 300#endif /* CONFIG_SUNRPC_SWAP */
 301
 302#endif /* _LINUX_SUNRPC_SCHED_H_ */
 303