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	const struct 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};
39
40/*
41 * This describes a timeout strategy
42 */
43struct 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 */
54struct 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
107typedef void			(*rpc_action)(struct rpc_task *);
108
109struct 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
116struct 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#define RPC_TASK_RUNNING	0
155#define RPC_TASK_QUEUED		1
156#define RPC_TASK_ACTIVE		2
157#define RPC_TASK_NEED_XMIT	3
158#define RPC_TASK_NEED_RECV	4
159#define RPC_TASK_MSG_PIN_WAIT	5
160#define RPC_TASK_SIGNALLED	6
161
162#define rpc_test_and_set_running(t) \
163				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
164#define rpc_clear_running(t)	clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
165
166#define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
167#define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
168#define rpc_clear_queued(t)	clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
169
170#define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
171
172#define RPC_SIGNALLED(t)	test_bit(RPC_TASK_SIGNALLED, &(t)->tk_runstate)
173
174/*
175 * Task priorities.
176 * Note: if you change these, you must also change
177 * the task initialization definitions below.
178 */
179#define RPC_PRIORITY_LOW	(-1)
180#define RPC_PRIORITY_NORMAL	(0)
181#define RPC_PRIORITY_HIGH	(1)
182#define RPC_PRIORITY_PRIVILEGED	(2)
183#define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
184
185struct rpc_timer {
186	struct list_head list;
187	unsigned long expires;
188	struct delayed_work dwork;
189};
190
191/*
192 * RPC synchronization objects
193 */
194struct rpc_wait_queue {
195	spinlock_t		lock;
196	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
197	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
198	unsigned char		priority;		/* current priority */
199	unsigned char		nr;			/* # tasks remaining for cookie */
200	unsigned int		qlen;			/* total # tasks waiting in queue */
201	struct rpc_timer	timer_list;
202#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
203	const char *		name;
204#endif
205};
206
207/*
208 * This is the # requests to send consecutively
209 * from a single cookie.  The aim is to improve
210 * performance of NFS operations such as read/write.
211 */
212#define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
213
214/*
215 * Function prototypes
216 */
217struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
218struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
219struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
220		struct rpc_timeout *timeout);
221void		rpc_put_task(struct rpc_task *);
222void		rpc_put_task_async(struct rpc_task *);
223bool		rpc_task_set_rpc_status(struct rpc_task *task, int rpc_status);
224void		rpc_task_try_cancel(struct rpc_task *task, int error);
225void		rpc_signal_task(struct rpc_task *);
226void		rpc_exit_task(struct rpc_task *);
227void		rpc_exit(struct rpc_task *, int);
228void		rpc_release_calldata(const struct rpc_call_ops *, void *);
229void		rpc_killall_tasks(struct rpc_clnt *);
230unsigned long	rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
231				 bool (*fnmatch)(const struct rpc_task *,
232						 const void *),
233				 const void *data);
234void		rpc_execute(struct rpc_task *);
235void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
236void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
237void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
238unsigned long	rpc_task_timeout(const struct rpc_task *task);
239void		rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
240					struct rpc_task *task,
241					rpc_action action,
242					unsigned long timeout);
243void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
244					rpc_action action);
245void		rpc_sleep_on_priority_timeout(struct rpc_wait_queue *queue,
246					struct rpc_task *task,
247					unsigned long timeout,
248					int priority);
249void		rpc_sleep_on_priority(struct rpc_wait_queue *,
250					struct rpc_task *,
251					int priority);
252void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
253					struct rpc_task *);
254void		rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
255						   struct rpc_task *,
256						   int);
257void		rpc_wake_up(struct rpc_wait_queue *);
258struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
259struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
260					struct rpc_wait_queue *,
261					bool (*)(struct rpc_task *, void *),
262					void *);
263struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
264					bool (*)(struct rpc_task *, void *),
265					void *);
266void		rpc_wake_up_status(struct rpc_wait_queue *, int);
267void		rpc_delay(struct rpc_task *, unsigned long);
268int		rpc_malloc(struct rpc_task *);
269void		rpc_free(struct rpc_task *);
270int		rpciod_up(void);
271void		rpciod_down(void);
272int		rpc_wait_for_completion_task(struct rpc_task *task);
273#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
274struct net;
275void		rpc_show_tasks(struct net *);
276#endif
277int		rpc_init_mempool(void);
278void		rpc_destroy_mempool(void);
279extern struct workqueue_struct *rpciod_workqueue;
280extern struct workqueue_struct *xprtiod_workqueue;
281void		rpc_prepare_task(struct rpc_task *task);
282gfp_t		rpc_task_gfp_mask(void);
283
284#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
285static inline const char * rpc_qname(const struct rpc_wait_queue *q)
286{
287	return ((q && q->name) ? q->name : "unknown");
288}
289
290static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
291		const char *name)
292{
293	q->name = name;
294}
295#else
296static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
297		const char *name)
298{
299}
300#endif
301
302#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
303int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
304void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
305#else
306static inline int
307rpc_clnt_swap_activate(struct rpc_clnt *clnt)
308{
309	return -EINVAL;
310}
311
312static inline void
313rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
314{
315}
316#endif /* CONFIG_SUNRPC_SWAP */
317
318#endif /* _LINUX_SUNRPC_SCHED_H_ */
319