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)
rpc_qname(const struct rpc_wait_queue * q)287  static inline const char * rpc_qname(const struct rpc_wait_queue *q)
288  {
289  	return ((q && q->name) ? q->name : "unknown");
290  }
291  
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)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
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)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
rpc_clnt_swap_activate(struct rpc_clnt * clnt)309  rpc_clnt_swap_activate(struct rpc_clnt *clnt)
310  {
311  	return -EINVAL;
312  }
313  
314  static inline void
rpc_clnt_swap_deactivate(struct rpc_clnt * clnt)315  rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
316  {
317  }
318  #endif /* CONFIG_SUNRPC_SWAP */
319  
320  #endif /* _LINUX_SUNRPC_SCHED_H_ */
321