1/*
2 * linux/include/linux/sunrpc/sched.h
3 *
4 * Scheduling primitives for kernel Sun RPC.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#ifndef _LINUX_SUNRPC_SCHED_H_
10#define _LINUX_SUNRPC_SCHED_H_
11
12#include <linux/timer.h>
13#include <linux/ktime.h>
14#include <linux/sunrpc/types.h>
15#include <linux/spinlock.h>
16#include <linux/wait.h>
17#include <linux/workqueue.h>
18#include <linux/sunrpc/xdr.h>
19
20/*
21 * This is the actual RPC procedure call info.
22 */
23struct rpc_procinfo;
24struct rpc_message {
25	struct rpc_procinfo *	rpc_proc;	/* Procedure information */
26	void *			rpc_argp;	/* Arguments */
27	void *			rpc_resp;	/* Result */
28	struct rpc_cred *	rpc_cred;	/* Credentials */
29};
30
31struct rpc_call_ops;
32struct rpc_wait_queue;
33struct rpc_wait {
34	struct list_head	list;		/* wait queue links */
35	struct list_head	links;		/* Links to related tasks */
36	struct list_head	timer_list;	/* Timer list */
37	unsigned long		expires;
38};
39
40/*
41 * This is the RPC task struct
42 */
43struct rpc_task {
44	atomic_t		tk_count;	/* Reference count */
45	struct list_head	tk_task;	/* global list of tasks */
46	struct rpc_clnt *	tk_client;	/* RPC client */
47	struct rpc_rqst *	tk_rqstp;	/* RPC request */
48
49	/*
50	 * RPC call state
51	 */
52	struct rpc_message	tk_msg;		/* RPC call info */
53
54	/*
55	 * callback	to be executed after waking up
56	 * action	next procedure for async tasks
57	 * tk_ops	caller callbacks
58	 */
59	void			(*tk_callback)(struct rpc_task *);
60	void			(*tk_action)(struct rpc_task *);
61	const struct rpc_call_ops *tk_ops;
62	void *			tk_calldata;
63
64	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
65	unsigned long		tk_runstate;	/* Task run status */
66	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
67						 * be any workqueue
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	ktime_t			tk_start;	/* RPC task init timestamp */
76
77	pid_t			tk_owner;	/* Process id for batching tasks */
78	int			tk_status;	/* result of last operation */
79	unsigned short		tk_flags;	/* misc flags */
80	unsigned short		tk_timeouts;	/* maj timeouts */
81
82#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
83	unsigned short		tk_pid;		/* debugging aid */
84#endif
85	unsigned char		tk_priority : 2,/* Task priority */
86				tk_garb_retry : 2,
87				tk_cred_retry : 2,
88				tk_rebind_retry : 2;
89};
90
91typedef void			(*rpc_action)(struct rpc_task *);
92
93struct rpc_call_ops {
94	void (*rpc_call_prepare)(struct rpc_task *, void *);
95	void (*rpc_call_done)(struct rpc_task *, void *);
96	void (*rpc_count_stats)(struct rpc_task *, void *);
97	void (*rpc_release)(void *);
98};
99
100struct rpc_task_setup {
101	struct rpc_task *task;
102	struct rpc_clnt *rpc_client;
103	const struct rpc_message *rpc_message;
104	const struct rpc_call_ops *callback_ops;
105	void *callback_data;
106	struct workqueue_struct *workqueue;
107	unsigned short flags;
108	signed char priority;
109};
110
111/*
112 * RPC task flags
113 */
114#define RPC_TASK_ASYNC		0x0001		/* is an async task */
115#define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
116#define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
117#define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
118#define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
119#define RPC_TASK_KILLED		0x0100		/* task was killed */
120#define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
121#define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
122#define RPC_TASK_SENT		0x0800		/* message was sent */
123#define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
124#define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
125#define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
126
127#define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
128#define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
129#define RPC_DO_ROOTOVERRIDE(t)	((t)->tk_flags & RPC_TASK_ROOTCREDS)
130#define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)
131#define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
132#define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
133#define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
134
135#define RPC_TASK_RUNNING	0
136#define RPC_TASK_QUEUED		1
137#define RPC_TASK_ACTIVE		2
138
139#define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
140#define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
141#define rpc_test_and_set_running(t) \
142				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
143#define rpc_clear_running(t)	\
144	do { \
145		smp_mb__before_atomic(); \
146		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
147		smp_mb__after_atomic(); \
148	} while (0)
149
150#define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
151#define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
152#define rpc_clear_queued(t)	\
153	do { \
154		smp_mb__before_atomic(); \
155		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
156		smp_mb__after_atomic(); \
157	} while (0)
158
159#define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
160
161/*
162 * Task priorities.
163 * Note: if you change these, you must also change
164 * the task initialization definitions below.
165 */
166#define RPC_PRIORITY_LOW	(-1)
167#define RPC_PRIORITY_NORMAL	(0)
168#define RPC_PRIORITY_HIGH	(1)
169#define RPC_PRIORITY_PRIVILEGED	(2)
170#define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
171
172struct rpc_timer {
173	struct timer_list timer;
174	struct list_head list;
175	unsigned long expires;
176};
177
178/*
179 * RPC synchronization objects
180 */
181struct rpc_wait_queue {
182	spinlock_t		lock;
183	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
184	pid_t			owner;			/* process id of last task serviced */
185	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
186	unsigned char		priority;		/* current priority */
187	unsigned char		nr;			/* # tasks remaining for cookie */
188	unsigned short		qlen;			/* total # tasks waiting in queue */
189	struct rpc_timer	timer_list;
190#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
191	const char *		name;
192#endif
193};
194
195/*
196 * This is the # requests to send consecutively
197 * from a single cookie.  The aim is to improve
198 * performance of NFS operations such as read/write.
199 */
200#define RPC_BATCH_COUNT			16
201#define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
202
203/*
204 * Function prototypes
205 */
206struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
207struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
208struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
209				const struct rpc_call_ops *ops);
210void		rpc_put_task(struct rpc_task *);
211void		rpc_put_task_async(struct rpc_task *);
212void		rpc_exit_task(struct rpc_task *);
213void		rpc_exit(struct rpc_task *, int);
214void		rpc_release_calldata(const struct rpc_call_ops *, void *);
215void		rpc_killall_tasks(struct rpc_clnt *);
216void		rpc_execute(struct rpc_task *);
217void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
218void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
219void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
220void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
221					rpc_action action);
222void		rpc_sleep_on_priority(struct rpc_wait_queue *,
223					struct rpc_task *,
224					rpc_action action,
225					int priority);
226void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
227					struct rpc_task *);
228void		rpc_wake_up(struct rpc_wait_queue *);
229struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
230struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
231					bool (*)(struct rpc_task *, void *),
232					void *);
233void		rpc_wake_up_status(struct rpc_wait_queue *, int);
234void		rpc_delay(struct rpc_task *, unsigned long);
235void *		rpc_malloc(struct rpc_task *, size_t);
236void		rpc_free(void *);
237int		rpciod_up(void);
238void		rpciod_down(void);
239int		__rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
240#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
241struct net;
242void		rpc_show_tasks(struct net *);
243#endif
244int		rpc_init_mempool(void);
245void		rpc_destroy_mempool(void);
246extern struct workqueue_struct *rpciod_workqueue;
247void		rpc_prepare_task(struct rpc_task *task);
248
249static inline int rpc_wait_for_completion_task(struct rpc_task *task)
250{
251	return __rpc_wait_for_completion_task(task, NULL);
252}
253
254#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
255static inline const char * rpc_qname(const struct rpc_wait_queue *q)
256{
257	return ((q && q->name) ? q->name : "unknown");
258}
259
260static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
261		const char *name)
262{
263	q->name = name;
264}
265#else
266static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
267		const char *name)
268{
269}
270#endif
271
272#endif /* _LINUX_SUNRPC_SCHED_H_ */
273