xref: /openbmc/linux/include/linux/sunrpc/sched.h (revision 1a4e39c2e5ca2eb494a53ecd73055562f690bca0)
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  */
23 struct rpc_procinfo;
24 struct 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 
31 struct rpc_call_ops;
32 struct rpc_wait_queue;
33 struct 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  */
43 struct 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 defined(RPC_DEBUG) || defined(RPC_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 
91 typedef void			(*rpc_action)(struct rpc_task *);
92 
93 struct 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 
100 struct 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 
172 struct rpc_timer {
173 	struct timer_list timer;
174 	struct list_head list;
175 	unsigned long expires;
176 };
177 
178 /*
179  * RPC synchronization objects
180  */
181 struct 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 defined(RPC_DEBUG) || defined(RPC_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  */
206 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
207 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
208 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
209 				const struct rpc_call_ops *ops);
210 void		rpc_put_task(struct rpc_task *);
211 void		rpc_put_task_async(struct rpc_task *);
212 void		rpc_exit_task(struct rpc_task *);
213 void		rpc_exit(struct rpc_task *, int);
214 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
215 void		rpc_killall_tasks(struct rpc_clnt *);
216 void		rpc_execute(struct rpc_task *);
217 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
218 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
219 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
220 void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
221 					rpc_action action);
222 void		rpc_sleep_on_priority(struct rpc_wait_queue *,
223 					struct rpc_task *,
224 					rpc_action action,
225 					int priority);
226 void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
227 					struct rpc_task *);
228 void		rpc_wake_up(struct rpc_wait_queue *);
229 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
230 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
231 					bool (*)(struct rpc_task *, void *),
232 					void *);
233 void		rpc_wake_up_status(struct rpc_wait_queue *, int);
234 void		rpc_delay(struct rpc_task *, unsigned long);
235 void *		rpc_malloc(struct rpc_task *, size_t);
236 void		rpc_free(void *);
237 int		rpciod_up(void);
238 void		rpciod_down(void);
239 int		__rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
240 #ifdef RPC_DEBUG
241 struct net;
242 void		rpc_show_tasks(struct net *);
243 #endif
244 int		rpc_init_mempool(void);
245 void		rpc_destroy_mempool(void);
246 extern struct workqueue_struct *rpciod_workqueue;
247 void		rpc_prepare_task(struct rpc_task *task);
248 
249 static 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 defined(RPC_DEBUG) || defined (RPC_TRACEPOINTS)
255 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
256 {
257 	return ((q && q->name) ? q->name : "unknown");
258 }
259 
260 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
261 		const char *name)
262 {
263 	q->name = name;
264 }
265 #else
266 static 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