xref: /openbmc/linux/include/linux/sunrpc/sched.h (revision 17bc4815de586d001c82d0ddf75247283c3f002a)
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 	unsigned long		expires;
39 };
40 
41 /*
42  * This is the RPC task struct
43  */
44 struct rpc_task {
45 	atomic_t		tk_count;	/* Reference count */
46 	int			tk_status;	/* result of last operation */
47 	struct list_head	tk_task;	/* global list of tasks */
48 
49 	/*
50 	 * callback	to be executed after waking up
51 	 * action	next procedure for async tasks
52 	 */
53 	void			(*tk_callback)(struct rpc_task *);
54 	void			(*tk_action)(struct rpc_task *);
55 
56 	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
57 	unsigned long		tk_runstate;	/* Task run status */
58 
59 	struct rpc_wait_queue 	*tk_waitqueue;	/* RPC wait queue we're on */
60 	union {
61 		struct work_struct	tk_work;	/* Async task work queue */
62 		struct rpc_wait		tk_wait;	/* RPC wait */
63 	} u;
64 
65 	/*
66 	 * RPC call state
67 	 */
68 	struct rpc_message	tk_msg;		/* RPC call info */
69 	void *			tk_calldata;	/* Caller private data */
70 	const struct rpc_call_ops *tk_ops;	/* Caller callbacks */
71 
72 	struct rpc_clnt *	tk_client;	/* RPC client */
73 	struct rpc_xprt *	tk_xprt;	/* Transport */
74 	struct rpc_cred *	tk_op_cred;	/* cred being operated on */
75 
76 	struct rpc_rqst *	tk_rqstp;	/* RPC request */
77 
78 	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
79 						 * be any workqueue
80 						 */
81 	ktime_t			tk_start;	/* RPC task init timestamp */
82 
83 	pid_t			tk_owner;	/* Process id for batching tasks */
84 	unsigned short		tk_flags;	/* misc flags */
85 	unsigned short		tk_timeouts;	/* maj timeouts */
86 
87 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
88 	unsigned short		tk_pid;		/* debugging aid */
89 #endif
90 	unsigned char		tk_priority : 2,/* Task priority */
91 				tk_garb_retry : 2,
92 				tk_cred_retry : 2,
93 				tk_rebind_retry : 2;
94 };
95 
96 typedef void			(*rpc_action)(struct rpc_task *);
97 
98 struct rpc_call_ops {
99 	void (*rpc_call_prepare)(struct rpc_task *, void *);
100 	void (*rpc_call_done)(struct rpc_task *, void *);
101 	void (*rpc_count_stats)(struct rpc_task *, void *);
102 	void (*rpc_release)(void *);
103 };
104 
105 struct rpc_task_setup {
106 	struct rpc_task *task;
107 	struct rpc_clnt *rpc_client;
108 	struct rpc_xprt *rpc_xprt;
109 	struct rpc_cred *rpc_op_cred;	/* credential being operated on */
110 	const struct rpc_message *rpc_message;
111 	const struct rpc_call_ops *callback_ops;
112 	void *callback_data;
113 	struct workqueue_struct *workqueue;
114 	unsigned short flags;
115 	signed char priority;
116 };
117 
118 /*
119  * RPC task flags
120  */
121 #define RPC_TASK_ASYNC		0x0001		/* is an async task */
122 #define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
123 #define RPC_TASK_NULLCREDS	0x0010		/* Use AUTH_NULL credential */
124 #define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
125 #define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
126 #define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
127 #define RPC_TASK_KILLED		0x0100		/* task was killed */
128 #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
129 #define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
130 #define RPC_TASK_SENT		0x0800		/* message was sent */
131 #define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
132 #define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
133 #define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
134 
135 #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
136 #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
137 #define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)
138 #define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
139 #define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
140 #define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
141 
142 #define RPC_TASK_RUNNING	0
143 #define RPC_TASK_QUEUED		1
144 #define RPC_TASK_ACTIVE		2
145 #define RPC_TASK_NEED_XMIT	3
146 #define RPC_TASK_NEED_RECV	4
147 #define RPC_TASK_MSG_PIN_WAIT	5
148 
149 #define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
150 #define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
151 #define rpc_test_and_set_running(t) \
152 				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
153 #define rpc_clear_running(t)	\
154 	do { \
155 		smp_mb__before_atomic(); \
156 		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
157 		smp_mb__after_atomic(); \
158 	} while (0)
159 
160 #define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
161 #define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
162 #define rpc_clear_queued(t)	\
163 	do { \
164 		smp_mb__before_atomic(); \
165 		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
166 		smp_mb__after_atomic(); \
167 	} while (0)
168 
169 #define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
170 
171 /*
172  * Task priorities.
173  * Note: if you change these, you must also change
174  * the task initialization definitions below.
175  */
176 #define RPC_PRIORITY_LOW	(-1)
177 #define RPC_PRIORITY_NORMAL	(0)
178 #define RPC_PRIORITY_HIGH	(1)
179 #define RPC_PRIORITY_PRIVILEGED	(2)
180 #define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
181 
182 struct rpc_timer {
183 	struct timer_list timer;
184 	struct list_head list;
185 	unsigned long expires;
186 };
187 
188 /*
189  * RPC synchronization objects
190  */
191 struct rpc_wait_queue {
192 	spinlock_t		lock;
193 	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
194 	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
195 	unsigned char		priority;		/* current priority */
196 	unsigned char		nr;			/* # tasks remaining for cookie */
197 	unsigned short		qlen;			/* total # tasks waiting in queue */
198 	struct rpc_timer	timer_list;
199 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
200 	const char *		name;
201 #endif
202 };
203 
204 /*
205  * This is the # requests to send consecutively
206  * from a single cookie.  The aim is to improve
207  * performance of NFS operations such as read/write.
208  */
209 #define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
210 
211 /*
212  * Function prototypes
213  */
214 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
215 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
216 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
217 void		rpc_put_task(struct rpc_task *);
218 void		rpc_put_task_async(struct rpc_task *);
219 void		rpc_exit_task(struct rpc_task *);
220 void		rpc_exit(struct rpc_task *, int);
221 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
222 void		rpc_killall_tasks(struct rpc_clnt *);
223 void		rpc_execute(struct rpc_task *);
224 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
225 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
226 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
227 void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
228 					rpc_action action);
229 void		rpc_sleep_on_priority(struct rpc_wait_queue *,
230 					struct rpc_task *,
231 					rpc_action action,
232 					int priority);
233 void rpc_wake_up_queued_task_on_wq(struct workqueue_struct *wq,
234 		struct rpc_wait_queue *queue,
235 		struct rpc_task *task);
236 void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
237 					struct rpc_task *);
238 void		rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
239 						   struct rpc_task *,
240 						   int);
241 void		rpc_wake_up(struct rpc_wait_queue *);
242 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
243 struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
244 					struct rpc_wait_queue *,
245 					bool (*)(struct rpc_task *, void *),
246 					void *);
247 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
248 					bool (*)(struct rpc_task *, void *),
249 					void *);
250 void		rpc_wake_up_status(struct rpc_wait_queue *, int);
251 void		rpc_delay(struct rpc_task *, unsigned long);
252 int		rpc_malloc(struct rpc_task *);
253 void		rpc_free(struct rpc_task *);
254 int		rpciod_up(void);
255 void		rpciod_down(void);
256 int		__rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
257 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
258 struct net;
259 void		rpc_show_tasks(struct net *);
260 #endif
261 int		rpc_init_mempool(void);
262 void		rpc_destroy_mempool(void);
263 extern struct workqueue_struct *rpciod_workqueue;
264 extern struct workqueue_struct *xprtiod_workqueue;
265 void		rpc_prepare_task(struct rpc_task *task);
266 
267 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
268 {
269 	return __rpc_wait_for_completion_task(task, NULL);
270 }
271 
272 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
273 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
274 {
275 	return ((q && q->name) ? q->name : "unknown");
276 }
277 
278 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
279 		const char *name)
280 {
281 	q->name = name;
282 }
283 #else
284 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
285 		const char *name)
286 {
287 }
288 #endif
289 
290 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
291 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
292 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
293 #else
294 static inline int
295 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
296 {
297 	return -EINVAL;
298 }
299 
300 static inline void
301 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
302 {
303 }
304 #endif /* CONFIG_SUNRPC_SWAP */
305 
306 #endif /* _LINUX_SUNRPC_SCHED_H_ */
307