xref: /linux-6.15/include/linux/sunrpc/sched.h (revision bb7e5ce7)
1 /*
2  * linux/include/linux/sunrpc/sched.h
3  *
4  * Scheduling primitives for kernel Sun RPC.
5  *
6  * Copyright (C) 1996, Olaf Kirch <[email protected]>
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_bit.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 	const 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 	int			tk_status;	/* result of last operation */
46 	struct list_head	tk_task;	/* global list of tasks */
47 
48 	/*
49 	 * callback	to be executed after waking up
50 	 * action	next procedure for async tasks
51 	 */
52 	void			(*tk_callback)(struct rpc_task *);
53 	void			(*tk_action)(struct rpc_task *);
54 
55 	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
56 	unsigned long		tk_runstate;	/* Task run status */
57 
58 	struct rpc_wait_queue 	*tk_waitqueue;	/* RPC wait queue we're on */
59 	union {
60 		struct work_struct	tk_work;	/* Async task work queue */
61 		struct rpc_wait		tk_wait;	/* RPC wait */
62 	} u;
63 
64 	/*
65 	 * RPC call state
66 	 */
67 	struct rpc_message	tk_msg;		/* RPC call info */
68 	void *			tk_calldata;	/* Caller private data */
69 	const struct rpc_call_ops *tk_ops;	/* Caller callbacks */
70 
71 	struct rpc_clnt *	tk_client;	/* RPC client */
72 	struct rpc_xprt *	tk_xprt;	/* Transport */
73 
74 	struct rpc_rqst *	tk_rqstp;	/* RPC request */
75 
76 	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
77 						 * be any workqueue
78 						 */
79 	ktime_t			tk_start;	/* RPC task init timestamp */
80 
81 	pid_t			tk_owner;	/* Process id for batching tasks */
82 	unsigned short		tk_flags;	/* misc flags */
83 	unsigned short		tk_timeouts;	/* maj timeouts */
84 
85 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
86 	unsigned short		tk_pid;		/* debugging aid */
87 #endif
88 	unsigned char		tk_priority : 2,/* Task priority */
89 				tk_garb_retry : 2,
90 				tk_cred_retry : 2,
91 				tk_rebind_retry : 2;
92 };
93 
94 typedef void			(*rpc_action)(struct rpc_task *);
95 
96 struct rpc_call_ops {
97 	void (*rpc_call_prepare)(struct rpc_task *, void *);
98 	void (*rpc_call_done)(struct rpc_task *, void *);
99 	void (*rpc_count_stats)(struct rpc_task *, void *);
100 	void (*rpc_release)(void *);
101 };
102 
103 struct rpc_task_setup {
104 	struct rpc_task *task;
105 	struct rpc_clnt *rpc_client;
106 	struct rpc_xprt *rpc_xprt;
107 	const struct rpc_message *rpc_message;
108 	const struct rpc_call_ops *callback_ops;
109 	void *callback_data;
110 	struct workqueue_struct *workqueue;
111 	unsigned short flags;
112 	signed char priority;
113 };
114 
115 /*
116  * RPC task flags
117  */
118 #define RPC_TASK_ASYNC		0x0001		/* is an async task */
119 #define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
120 #define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
121 #define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
122 #define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
123 #define RPC_TASK_KILLED		0x0100		/* task was killed */
124 #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
125 #define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
126 #define RPC_TASK_SENT		0x0800		/* message was sent */
127 #define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
128 #define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
129 #define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
130 
131 #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
132 #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
133 #define RPC_DO_ROOTOVERRIDE(t)	((t)->tk_flags & RPC_TASK_ROOTCREDS)
134 #define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)
135 #define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
136 #define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
137 #define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
138 
139 #define RPC_TASK_RUNNING	0
140 #define RPC_TASK_QUEUED		1
141 #define RPC_TASK_ACTIVE		2
142 #define RPC_TASK_MSG_RECV	3
143 #define RPC_TASK_MSG_RECV_WAIT	4
144 
145 #define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
146 #define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
147 #define rpc_test_and_set_running(t) \
148 				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
149 #define rpc_clear_running(t)	\
150 	do { \
151 		smp_mb__before_atomic(); \
152 		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
153 		smp_mb__after_atomic(); \
154 	} while (0)
155 
156 #define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
157 #define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
158 #define rpc_clear_queued(t)	\
159 	do { \
160 		smp_mb__before_atomic(); \
161 		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
162 		smp_mb__after_atomic(); \
163 	} while (0)
164 
165 #define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
166 
167 /*
168  * Task priorities.
169  * Note: if you change these, you must also change
170  * the task initialization definitions below.
171  */
172 #define RPC_PRIORITY_LOW	(-1)
173 #define RPC_PRIORITY_NORMAL	(0)
174 #define RPC_PRIORITY_HIGH	(1)
175 #define RPC_PRIORITY_PRIVILEGED	(2)
176 #define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
177 
178 struct rpc_timer {
179 	struct timer_list timer;
180 	struct list_head list;
181 	unsigned long expires;
182 };
183 
184 /*
185  * RPC synchronization objects
186  */
187 struct rpc_wait_queue {
188 	spinlock_t		lock;
189 	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
190 	pid_t			owner;			/* process id of last task serviced */
191 	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
192 	unsigned char		priority;		/* current priority */
193 	unsigned char		nr;			/* # tasks remaining for cookie */
194 	unsigned short		qlen;			/* total # tasks waiting in queue */
195 	struct rpc_timer	timer_list;
196 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
197 	const char *		name;
198 #endif
199 };
200 
201 /*
202  * This is the # requests to send consecutively
203  * from a single cookie.  The aim is to improve
204  * performance of NFS operations such as read/write.
205  */
206 #define RPC_BATCH_COUNT			16
207 #define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
208 
209 /*
210  * Function prototypes
211  */
212 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
213 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
214 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
215 void		rpc_put_task(struct rpc_task *);
216 void		rpc_put_task_async(struct rpc_task *);
217 void		rpc_exit_task(struct rpc_task *);
218 void		rpc_exit(struct rpc_task *, int);
219 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
220 void		rpc_killall_tasks(struct rpc_clnt *);
221 void		rpc_execute(struct rpc_task *);
222 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
223 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
224 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
225 void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
226 					rpc_action action);
227 void		rpc_sleep_on_priority(struct rpc_wait_queue *,
228 					struct rpc_task *,
229 					rpc_action action,
230 					int priority);
231 void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
232 					struct rpc_task *);
233 void		rpc_wake_up(struct rpc_wait_queue *);
234 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
235 struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
236 					struct rpc_wait_queue *,
237 					bool (*)(struct rpc_task *, void *),
238 					void *);
239 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
240 					bool (*)(struct rpc_task *, void *),
241 					void *);
242 void		rpc_wake_up_status(struct rpc_wait_queue *, int);
243 void		rpc_delay(struct rpc_task *, unsigned long);
244 int		rpc_malloc(struct rpc_task *);
245 void		rpc_free(struct rpc_task *);
246 int		rpciod_up(void);
247 void		rpciod_down(void);
248 int		__rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
249 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
250 struct net;
251 void		rpc_show_tasks(struct net *);
252 #endif
253 int		rpc_init_mempool(void);
254 void		rpc_destroy_mempool(void);
255 extern struct workqueue_struct *rpciod_workqueue;
256 extern struct workqueue_struct *xprtiod_workqueue;
257 void		rpc_prepare_task(struct rpc_task *task);
258 
259 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
260 {
261 	return __rpc_wait_for_completion_task(task, NULL);
262 }
263 
264 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
265 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
266 {
267 	return ((q && q->name) ? q->name : "unknown");
268 }
269 
270 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
271 		const char *name)
272 {
273 	q->name = name;
274 }
275 #else
276 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
277 		const char *name)
278 {
279 }
280 #endif
281 
282 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
283 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
284 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
285 #else
286 static inline int
287 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
288 {
289 	return -EINVAL;
290 }
291 
292 static inline void
293 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
294 {
295 }
296 #endif /* CONFIG_SUNRPC_SWAP */
297 
298 #endif /* _LINUX_SUNRPC_SCHED_H_ */
299