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_MOVEABLE	0x0004		/* nfs4.1+ rpc tasks */
125 #define RPC_TASK_NULLCREDS	0x0010		/* Use AUTH_NULL credential */
126 #define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
127 #define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
128 #define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
129 #define	RPC_TASK_NO_ROUND_ROBIN	0x0100		/* send requests on "main" xprt */
130 #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
131 #define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
132 #define RPC_TASK_SENT		0x0800		/* message was sent */
133 #define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
134 #define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
135 #define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
136 #define RPC_TASK_CRED_NOREF	0x8000		/* No refcount on the credential */
137 
138 #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
139 #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
140 #define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
141 #define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
142 #define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
143 #define RPC_IS_MOVEABLE(t)	((t)->tk_flags & RPC_TASK_MOVEABLE)
144 
145 #define RPC_TASK_RUNNING	0
146 #define RPC_TASK_QUEUED		1
147 #define RPC_TASK_ACTIVE		2
148 #define RPC_TASK_NEED_XMIT	3
149 #define RPC_TASK_NEED_RECV	4
150 #define RPC_TASK_MSG_PIN_WAIT	5
151 #define RPC_TASK_SIGNALLED	6
152 
153 #define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
154 #define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
155 #define rpc_test_and_set_running(t) \
156 				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
157 #define rpc_clear_running(t)	\
158 	do { \
159 		smp_mb__before_atomic(); \
160 		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
161 		smp_mb__after_atomic(); \
162 	} while (0)
163 
164 #define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
165 #define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
166 #define rpc_clear_queued(t)	\
167 	do { \
168 		smp_mb__before_atomic(); \
169 		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
170 		smp_mb__after_atomic(); \
171 	} while (0)
172 
173 #define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
174 
175 #define RPC_SIGNALLED(t)	test_bit(RPC_TASK_SIGNALLED, &(t)->tk_runstate)
176 
177 /*
178  * Task priorities.
179  * Note: if you change these, you must also change
180  * the task initialization definitions below.
181  */
182 #define RPC_PRIORITY_LOW	(-1)
183 #define RPC_PRIORITY_NORMAL	(0)
184 #define RPC_PRIORITY_HIGH	(1)
185 #define RPC_PRIORITY_PRIVILEGED	(2)
186 #define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
187 
188 struct rpc_timer {
189 	struct list_head list;
190 	unsigned long expires;
191 	struct delayed_work dwork;
192 };
193 
194 /*
195  * RPC synchronization objects
196  */
197 struct rpc_wait_queue {
198 	spinlock_t		lock;
199 	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
200 	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
201 	unsigned char		priority;		/* current priority */
202 	unsigned char		nr;			/* # tasks remaining for cookie */
203 	unsigned short		qlen;			/* total # tasks waiting in queue */
204 	struct rpc_timer	timer_list;
205 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
206 	const char *		name;
207 #endif
208 };
209 
210 /*
211  * This is the # requests to send consecutively
212  * from a single cookie.  The aim is to improve
213  * performance of NFS operations such as read/write.
214  */
215 #define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
216 
217 /*
218  * Function prototypes
219  */
220 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
221 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
222 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
223 void		rpc_put_task(struct rpc_task *);
224 void		rpc_put_task_async(struct rpc_task *);
225 void		rpc_signal_task(struct rpc_task *);
226 void		rpc_exit_task(struct rpc_task *);
227 void		rpc_exit(struct rpc_task *, int);
228 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
229 void		rpc_killall_tasks(struct rpc_clnt *);
230 void		rpc_execute(struct rpc_task *);
231 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
232 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
233 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
234 unsigned long	rpc_task_timeout(const struct rpc_task *task);
235 void		rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
236 					struct rpc_task *task,
237 					rpc_action action,
238 					unsigned long timeout);
239 void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
240 					rpc_action action);
241 void		rpc_sleep_on_priority_timeout(struct rpc_wait_queue *queue,
242 					struct rpc_task *task,
243 					unsigned long timeout,
244 					int priority);
245 void		rpc_sleep_on_priority(struct rpc_wait_queue *,
246 					struct rpc_task *,
247 					int priority);
248 void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
249 					struct rpc_task *);
250 void		rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
251 						   struct rpc_task *,
252 						   int);
253 void		rpc_wake_up(struct rpc_wait_queue *);
254 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
255 struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
256 					struct rpc_wait_queue *,
257 					bool (*)(struct rpc_task *, void *),
258 					void *);
259 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
260 					bool (*)(struct rpc_task *, void *),
261 					void *);
262 void		rpc_wake_up_status(struct rpc_wait_queue *, int);
263 void		rpc_delay(struct rpc_task *, unsigned long);
264 int		rpc_malloc(struct rpc_task *);
265 void		rpc_free(struct rpc_task *);
266 int		rpciod_up(void);
267 void		rpciod_down(void);
268 int		__rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
269 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
270 struct net;
271 void		rpc_show_tasks(struct net *);
272 #endif
273 int		rpc_init_mempool(void);
274 void		rpc_destroy_mempool(void);
275 extern struct workqueue_struct *rpciod_workqueue;
276 extern struct workqueue_struct *xprtiod_workqueue;
277 void		rpc_prepare_task(struct rpc_task *task);
278 
rpc_wait_for_completion_task(struct rpc_task * task)279 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
280 {
281 	return __rpc_wait_for_completion_task(task, NULL);
282 }
283 
284 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
rpc_qname(const struct rpc_wait_queue * q)285 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
286 {
287 	return ((q && q->name) ? q->name : "unknown");
288 }
289 
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)290 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
291 		const char *name)
292 {
293 	q->name = name;
294 }
295 #else
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)296 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
297 		const char *name)
298 {
299 }
300 #endif
301 
302 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
303 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
304 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
305 #else
306 static inline int
rpc_clnt_swap_activate(struct rpc_clnt * clnt)307 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
308 {
309 	return -EINVAL;
310 }
311 
312 static inline void
rpc_clnt_swap_deactivate(struct rpc_clnt * clnt)313 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
314 {
315 }
316 #endif /* CONFIG_SUNRPC_SWAP */
317 
318 #endif /* _LINUX_SUNRPC_SCHED_H_ */
319