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 };
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 	int			tk_rpc_status;	/* Result of last RPC operation */
65 
66 	/*
67 	 * RPC call state
68 	 */
69 	struct rpc_message	tk_msg;		/* RPC call info */
70 	void *			tk_calldata;	/* Caller private data */
71 	const struct rpc_call_ops *tk_ops;	/* Caller callbacks */
72 
73 	struct rpc_clnt *	tk_client;	/* RPC client */
74 	struct rpc_xprt *	tk_xprt;	/* Transport */
75 	struct rpc_cred *	tk_op_cred;	/* cred being operated on */
76 
77 	struct rpc_rqst *	tk_rqstp;	/* RPC request */
78 
79 	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
80 						 * be any workqueue
81 						 */
82 	ktime_t			tk_start;	/* RPC task init timestamp */
83 
84 	pid_t			tk_owner;	/* Process id for batching tasks */
85 	unsigned short		tk_flags;	/* misc flags */
86 	unsigned short		tk_timeouts;	/* maj timeouts */
87 
88 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
89 	unsigned short		tk_pid;		/* debugging aid */
90 #endif
91 	unsigned char		tk_priority : 2,/* Task priority */
92 				tk_garb_retry : 2,
93 				tk_cred_retry : 2,
94 				tk_rebind_retry : 2;
95 };
96 
97 typedef void			(*rpc_action)(struct rpc_task *);
98 
99 struct rpc_call_ops {
100 	void (*rpc_call_prepare)(struct rpc_task *, void *);
101 	void (*rpc_call_done)(struct rpc_task *, void *);
102 	void (*rpc_count_stats)(struct rpc_task *, void *);
103 	void (*rpc_release)(void *);
104 };
105 
106 struct rpc_task_setup {
107 	struct rpc_task *task;
108 	struct rpc_clnt *rpc_client;
109 	struct rpc_xprt *rpc_xprt;
110 	struct rpc_cred *rpc_op_cred;	/* credential being operated on */
111 	const struct rpc_message *rpc_message;
112 	const struct rpc_call_ops *callback_ops;
113 	void *callback_data;
114 	struct workqueue_struct *workqueue;
115 	unsigned short flags;
116 	signed char priority;
117 };
118 
119 /*
120  * RPC task flags
121  */
122 #define RPC_TASK_ASYNC		0x0001		/* is an async task */
123 #define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
124 #define RPC_TASK_NULLCREDS	0x0010		/* Use AUTH_NULL credential */
125 #define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
126 #define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
127 #define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
128 #define	RPC_TASK_NO_ROUND_ROBIN	0x0100		/* send requests on "main" xprt */
129 #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
130 #define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
131 #define RPC_TASK_SENT		0x0800		/* message was sent */
132 #define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
133 #define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
134 #define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
135 
136 #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
137 #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
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 #define RPC_TASK_SIGNALLED	6
149 
150 #define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
151 #define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
152 #define rpc_test_and_set_running(t) \
153 				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
154 #define rpc_clear_running(t)	\
155 	do { \
156 		smp_mb__before_atomic(); \
157 		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
158 		smp_mb__after_atomic(); \
159 	} while (0)
160 
161 #define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
162 #define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
163 #define rpc_clear_queued(t)	\
164 	do { \
165 		smp_mb__before_atomic(); \
166 		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
167 		smp_mb__after_atomic(); \
168 	} while (0)
169 
170 #define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
171 
172 #define RPC_SIGNALLED(t)	test_bit(RPC_TASK_SIGNALLED, &(t)->tk_runstate)
173 
174 /*
175  * Task priorities.
176  * Note: if you change these, you must also change
177  * the task initialization definitions below.
178  */
179 #define RPC_PRIORITY_LOW	(-1)
180 #define RPC_PRIORITY_NORMAL	(0)
181 #define RPC_PRIORITY_HIGH	(1)
182 #define RPC_PRIORITY_PRIVILEGED	(2)
183 #define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
184 
185 struct rpc_timer {
186 	struct list_head list;
187 	unsigned long expires;
188 	struct delayed_work dwork;
189 };
190 
191 /*
192  * RPC synchronization objects
193  */
194 struct rpc_wait_queue {
195 	spinlock_t		lock;
196 	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
197 	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
198 	unsigned char		priority;		/* current priority */
199 	unsigned char		nr;			/* # tasks remaining for cookie */
200 	unsigned short		qlen;			/* total # tasks waiting in queue */
201 	struct rpc_timer	timer_list;
202 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
203 	const char *		name;
204 #endif
205 };
206 
207 /*
208  * This is the # requests to send consecutively
209  * from a single cookie.  The aim is to improve
210  * performance of NFS operations such as read/write.
211  */
212 #define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
213 
214 /*
215  * Function prototypes
216  */
217 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
218 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
219 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
220 void		rpc_put_task(struct rpc_task *);
221 void		rpc_put_task_async(struct rpc_task *);
222 void		rpc_signal_task(struct rpc_task *);
223 void		rpc_exit_task(struct rpc_task *);
224 void		rpc_exit(struct rpc_task *, int);
225 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
226 void		rpc_killall_tasks(struct rpc_clnt *);
227 void		rpc_execute(struct rpc_task *);
228 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
229 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
230 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
231 unsigned long	rpc_task_timeout(const struct rpc_task *task);
232 void		rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
233 					struct rpc_task *task,
234 					rpc_action action,
235 					unsigned long timeout);
236 void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
237 					rpc_action action);
238 void		rpc_sleep_on_priority_timeout(struct rpc_wait_queue *queue,
239 					struct rpc_task *task,
240 					unsigned long timeout,
241 					int priority);
242 void		rpc_sleep_on_priority(struct rpc_wait_queue *,
243 					struct rpc_task *,
244 					int priority);
245 void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
246 					struct rpc_task *);
247 void		rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
248 						   struct rpc_task *,
249 						   int);
250 void		rpc_wake_up(struct rpc_wait_queue *);
251 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
252 struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
253 					struct rpc_wait_queue *,
254 					bool (*)(struct rpc_task *, void *),
255 					void *);
256 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
257 					bool (*)(struct rpc_task *, void *),
258 					void *);
259 void		rpc_wake_up_status(struct rpc_wait_queue *, int);
260 void		rpc_delay(struct rpc_task *, unsigned long);
261 int		rpc_malloc(struct rpc_task *);
262 void		rpc_free(struct rpc_task *);
263 int		rpciod_up(void);
264 void		rpciod_down(void);
265 int		__rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
266 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
267 struct net;
268 void		rpc_show_tasks(struct net *);
269 #endif
270 int		rpc_init_mempool(void);
271 void		rpc_destroy_mempool(void);
272 extern struct workqueue_struct *rpciod_workqueue;
273 extern struct workqueue_struct *xprtiod_workqueue;
274 void		rpc_prepare_task(struct rpc_task *task);
275 
rpc_wait_for_completion_task(struct rpc_task * task)276 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
277 {
278 	return __rpc_wait_for_completion_task(task, NULL);
279 }
280 
281 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
rpc_qname(const struct rpc_wait_queue * q)282 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
283 {
284 	return ((q && q->name) ? q->name : "unknown");
285 }
286 
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)287 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
288 		const char *name)
289 {
290 	q->name = name;
291 }
292 #else
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)293 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
294 		const char *name)
295 {
296 }
297 #endif
298 
299 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
300 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
301 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
302 #else
303 static inline int
rpc_clnt_swap_activate(struct rpc_clnt * clnt)304 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
305 {
306 	return -EINVAL;
307 }
308 
309 static inline void
rpc_clnt_swap_deactivate(struct rpc_clnt * clnt)310 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
311 {
312 }
313 #endif /* CONFIG_SUNRPC_SWAP */
314 
315 #endif /* _LINUX_SUNRPC_SCHED_H_ */
316