aboutsummaryrefslogtreecommitdiff
path: root/include/linux/sunrpc/sched.h
blob: 8ea077db0099cc636a2c9053e7cd1cc17abec2a0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
/*
 * linux/include/linux/sunrpc/sched.h
 *
 * Scheduling primitives for kernel Sun RPC.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#ifndef _LINUX_SUNRPC_SCHED_H_
#define _LINUX_SUNRPC_SCHED_H_

#include <linux/timer.h>
#include <linux/sunrpc/types.h>
#include <linux/rcupdate.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/xdr.h>

/*
 * This is the actual RPC procedure call info.
 */
struct rpc_procinfo;
struct rpc_message {
	struct rpc_procinfo *	rpc_proc;	/* Procedure information */
	void *			rpc_argp;	/* Arguments */
	void *			rpc_resp;	/* Result */
	struct rpc_cred *	rpc_cred;	/* Credentials */
};

struct rpc_call_ops;
struct rpc_wait_queue;
struct rpc_wait {
	struct list_head	list;		/* wait queue links */
	struct list_head	links;		/* Links to related tasks */
	struct rpc_wait_queue *	rpc_waitq;	/* RPC wait queue we're on */
};

/*
 * This is the RPC task struct
 */
struct rpc_task {
#ifdef RPC_DEBUG
	unsigned long		tk_magic;	/* 0xf00baa */
#endif
	atomic_t		tk_count;	/* Reference count */
	struct list_head	tk_task;	/* global list of tasks */
	struct rpc_clnt *	tk_client;	/* RPC client */
	struct rpc_rqst *	tk_rqstp;	/* RPC request */
	int			tk_status;	/* result of last operation */

	/*
	 * RPC call state
	 */
	struct rpc_message	tk_msg;		/* RPC call info */
	__u8			tk_garb_retry;
	__u8			tk_cred_retry;

	unsigned long		tk_cookie;	/* Cookie for batching tasks */

	/*
	 * timeout_fn   to be executed by timer bottom half
	 * callback	to be executed after waking up
	 * action	next procedure for async tasks
	 * tk_ops	caller callbacks
	 */
	void			(*tk_timeout_fn)(struct rpc_task *);
	void			(*tk_callback)(struct rpc_task *);
	void			(*tk_action)(struct rpc_task *);
	const struct rpc_call_ops *tk_ops;
	void *			tk_calldata;

	/*
	 * tk_timer is used for async processing by the RPC scheduling
	 * primitives. You should not access this directly unless
	 * you have a pathological interest in kernel oopses.
	 */
	struct timer_list	tk_timer;	/* kernel timer */
	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
	unsigned short		tk_flags;	/* misc flags */
	unsigned char		tk_priority : 2;/* Task priority */
	unsigned long		tk_runstate;	/* Task run status */
	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
						 * be any workqueue
						 */
	union {
		struct work_struct	tk_work;	/* Async task work queue */
		struct rpc_wait		tk_wait;	/* RPC wait */
		struct rcu_head		tk_rcu;		/* for task deletion */
	} u;

	unsigned short		tk_timeouts;	/* maj timeouts */
	size_t			tk_bytes_sent;	/* total bytes sent */
	unsigned long		tk_start;	/* RPC task init timestamp */
	long			tk_rtt;		/* round-trip time (jiffies) */

#ifdef RPC_DEBUG
	unsigned short		tk_pid;		/* debugging aid */
#endif
};
#define tk_xprt			tk_client->cl_xprt

/* support walking a list of tasks on a wait queue */
#define	task_for_each(task, pos, head) \
	list_for_each(pos, head) \
		if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)

#define	task_for_first(task, head) \
	if (!list_empty(head) &&  \
	    ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))

typedef void			(*rpc_action)(struct rpc_task *);

struct rpc_call_ops {
	void (*rpc_call_prepare)(struct rpc_task *, void *);
	void (*rpc_call_done)(struct rpc_task *, void *);
	void (*rpc_release)(void *);
};


/*
 * RPC task flags
 */
#define RPC_TASK_ASYNC		0x0001		/* is an async task */
#define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
#define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
#define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
#define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
#define RPC_TASK_KILLED		0x0100		/* task was killed */
#define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
#define RPC_TASK_NOINTR		0x0400		/* uninterruptible task */

#define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
#define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
#define RPC_DO_ROOTOVERRIDE(t)	((t)->tk_flags & RPC_TASK_ROOTCREDS)
#define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)
#define RPC_DO_CALLBACK(t)	((t)->tk_callback != NULL)
#define RPC_IS_SOFT(t)		((t)->tk_flags & RPC_TASK_SOFT)
#define RPC_TASK_UNINTERRUPTIBLE(t) ((t)->tk_flags & RPC_TASK_NOINTR)

#define RPC_TASK_RUNNING	0
#define RPC_TASK_QUEUED		1
#define RPC_TASK_WAKEUP		2
#define RPC_TASK_HAS_TIMER	3
#define RPC_TASK_ACTIVE		4

#define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_test_and_set_running(t) \
				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_clear_running(t)	\
	do { \
		smp_mb__before_clear_bit(); \
		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
		smp_mb__after_clear_bit(); \
	} while (0)

#define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
#define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
#define rpc_clear_queued(t)	\
	do { \
		smp_mb__before_clear_bit(); \
		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
		smp_mb__after_clear_bit(); \
	} while (0)

#define rpc_start_wakeup(t) \
	(test_and_set_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate) == 0)
#define rpc_finish_wakeup(t) \
	do { \
		smp_mb__before_clear_bit(); \
		clear_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate); \
		smp_mb__after_clear_bit(); \
	} while (0)

#define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)

/*
 * Task priorities.
 * Note: if you change these, you must also change
 * the task initialization definitions below.
 */
#define RPC_PRIORITY_LOW	0
#define RPC_PRIORITY_NORMAL	1
#define RPC_PRIORITY_HIGH	2
#define RPC_NR_PRIORITY		(RPC_PRIORITY_HIGH+1)

/*
 * RPC synchronization objects
 */
struct rpc_wait_queue {
	spinlock_t		lock;
	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
	unsigned long		cookie;			/* cookie of last task serviced */
	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
	unsigned char		priority;		/* current priority */
	unsigned char		count;			/* # task groups remaining serviced so far */
	unsigned char		nr;			/* # tasks remaining for cookie */
	unsigned short		qlen;			/* total # tasks waiting in queue */
#ifdef RPC_DEBUG
	const char *		name;
#endif
};

/*
 * This is the # requests to send consecutively
 * from a single cookie.  The aim is to improve
 * performance of NFS operations such as read/write.
 */
#define RPC_BATCH_COUNT			16

#ifndef RPC_DEBUG
# define RPC_WAITQ_INIT(var,qname) { \
		.lock = __SPIN_LOCK_UNLOCKED(var.lock), \
		.tasks = { \
			[0] = LIST_HEAD_INIT(var.tasks[0]), \
			[1] = LIST_HEAD_INIT(var.tasks[1]), \
			[2] = LIST_HEAD_INIT(var.tasks[2]), \
		}, \
	}
#else
# define RPC_WAITQ_INIT(var,qname) { \
		.lock = __SPIN_LOCK_UNLOCKED(var.lock), \
		.tasks = { \
			[0] = LIST_HEAD_INIT(var.tasks[0]), \
			[1] = LIST_HEAD_INIT(var.tasks[1]), \
			[2] = LIST_HEAD_INIT(var.tasks[2]), \
		}, \
		.name = qname, \
	}
#endif
# define RPC_WAITQ(var,qname)      struct rpc_wait_queue var = RPC_WAITQ_INIT(var,qname)

#define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)

/*
 * Function prototypes
 */
struct rpc_task *rpc_new_task(struct rpc_clnt *, int flags,
				const struct rpc_call_ops *ops, void *data);
struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
				const struct rpc_call_ops *ops, void *data);
void		rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt,
				int flags, const struct rpc_call_ops *ops,
				void *data);
void		rpc_put_task(struct rpc_task *);
void		rpc_exit_task(struct rpc_task *);
void		rpc_release_calldata(const struct rpc_call_ops *, void *);
void		rpc_killall_tasks(struct rpc_clnt *);
void		rpc_execute(struct rpc_task *);
void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
					rpc_action action, rpc_action timer);
void		rpc_wake_up_task(struct rpc_task *);
void		rpc_wake_up(struct rpc_wait_queue *);
struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
void		rpc_wake_up_status(struct rpc_wait_queue *, int);
void		rpc_delay(struct rpc_task *, unsigned long);
void *		rpc_malloc(struct rpc_task *, size_t);
void		rpc_free(void *);
int		rpciod_up(void);
void		rpciod_down(void);
int		__rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
#ifdef RPC_DEBUG
void		rpc_show_tasks(void);
#endif
int		rpc_init_mempool(void);
void		rpc_destroy_mempool(void);
extern struct workqueue_struct *rpciod_workqueue;

static inline void rpc_exit(struct rpc_task *task, int status)
{
	task->tk_status = status;
	task->tk_action = rpc_exit_task;
}

static inline int rpc_wait_for_completion_task(struct rpc_task *task)
{
	return __rpc_wait_for_completion_task(task, NULL);
}

#ifdef RPC_DEBUG
static inline const char * rpc_qname(struct rpc_wait_queue *q)
{
	return ((q && q->name) ? q->name : "unknown");
}
#endif

#endif /* _LINUX_SUNRPC_SCHED_H_ */