xref: /linux-6.15/include/linux/sunrpc/sched.h (revision bcefe12e)
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/sunrpc/types.h>
14 #include <linux/spinlock.h>
15 #include <linux/wait.h>
16 #include <linux/workqueue.h>
17 #include <linux/sunrpc/xdr.h>
18 
19 /*
20  * This is the actual RPC procedure call info.
21  */
22 struct rpc_procinfo;
23 struct rpc_message {
24 	struct rpc_procinfo *	rpc_proc;	/* Procedure information */
25 	void *			rpc_argp;	/* Arguments */
26 	void *			rpc_resp;	/* Result */
27 	struct rpc_cred *	rpc_cred;	/* Credentials */
28 };
29 
30 struct rpc_call_ops;
31 struct rpc_wait_queue;
32 struct rpc_wait {
33 	struct list_head	list;		/* wait queue links */
34 	struct list_head	links;		/* Links to related tasks */
35 	struct list_head	timer_list;	/* Timer list */
36 	unsigned long		expires;
37 };
38 
39 /*
40  * This is the RPC task struct
41  */
42 struct rpc_task {
43 #ifdef RPC_DEBUG
44 	unsigned long		tk_magic;	/* 0xf00baa */
45 #endif
46 	atomic_t		tk_count;	/* Reference count */
47 	struct list_head	tk_task;	/* global list of tasks */
48 	struct rpc_clnt *	tk_client;	/* RPC client */
49 	struct rpc_rqst *	tk_rqstp;	/* RPC request */
50 	int			tk_status;	/* result of last operation */
51 
52 	/*
53 	 * RPC call state
54 	 */
55 	struct rpc_message	tk_msg;		/* RPC call info */
56 	__u8			tk_garb_retry;
57 	__u8			tk_cred_retry;
58 
59 	/*
60 	 * callback	to be executed after waking up
61 	 * action	next procedure for async tasks
62 	 * tk_ops	caller callbacks
63 	 */
64 	void			(*tk_callback)(struct rpc_task *);
65 	void			(*tk_action)(struct rpc_task *);
66 	const struct rpc_call_ops *tk_ops;
67 	void *			tk_calldata;
68 
69 	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
70 	unsigned short		tk_flags;	/* misc flags */
71 	unsigned long		tk_runstate;	/* Task run status */
72 	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
73 						 * be any workqueue
74 						 */
75 	struct rpc_wait_queue 	*tk_waitqueue;	/* RPC wait queue we're on */
76 	union {
77 		struct work_struct	tk_work;	/* Async task work queue */
78 		struct rpc_wait		tk_wait;	/* RPC wait */
79 	} u;
80 
81 	unsigned short		tk_timeouts;	/* maj timeouts */
82 	size_t			tk_bytes_sent;	/* total bytes sent */
83 	unsigned long		tk_start;	/* RPC task init timestamp */
84 	long			tk_rtt;		/* round-trip time (jiffies) */
85 
86 	pid_t			tk_owner;	/* Process id for batching tasks */
87 	unsigned char		tk_priority : 2;/* Task priority */
88 
89 #ifdef RPC_DEBUG
90 	unsigned short		tk_pid;		/* debugging aid */
91 #endif
92 };
93 #define tk_xprt			tk_client->cl_xprt
94 
95 /* support walking a list of tasks on a wait queue */
96 #define	task_for_each(task, pos, head) \
97 	list_for_each(pos, head) \
98 		if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
99 
100 #define	task_for_first(task, head) \
101 	if (!list_empty(head) &&  \
102 	    ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
103 
104 typedef void			(*rpc_action)(struct rpc_task *);
105 
106 struct rpc_call_ops {
107 	void (*rpc_call_prepare)(struct rpc_task *, void *);
108 	void (*rpc_call_done)(struct rpc_task *, void *);
109 	void (*rpc_release)(void *);
110 };
111 
112 struct rpc_task_setup {
113 	struct rpc_task *task;
114 	struct rpc_clnt *rpc_client;
115 	const struct rpc_message *rpc_message;
116 	const struct rpc_call_ops *callback_ops;
117 	void *callback_data;
118 	struct workqueue_struct *workqueue;
119 	unsigned short flags;
120 	signed char priority;
121 };
122 
123 /*
124  * RPC task flags
125  */
126 #define RPC_TASK_ASYNC		0x0001		/* is an async task */
127 #define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
128 #define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
129 #define RPC_TASK_ROOTCREDS	0x0040		/* force root creds */
130 #define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
131 #define RPC_TASK_KILLED		0x0100		/* task was killed */
132 #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
133 
134 #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
135 #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
136 #define RPC_DO_ROOTOVERRIDE(t)	((t)->tk_flags & RPC_TASK_ROOTCREDS)
137 #define RPC_ASSASSINATED(t)	((t)->tk_flags & RPC_TASK_KILLED)
138 #define RPC_IS_SOFT(t)		((t)->tk_flags & RPC_TASK_SOFT)
139 
140 #define RPC_TASK_RUNNING	0
141 #define RPC_TASK_QUEUED		1
142 #define RPC_TASK_ACTIVE		2
143 
144 #define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
145 #define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
146 #define rpc_test_and_set_running(t) \
147 				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
148 #define rpc_clear_running(t)	\
149 	do { \
150 		smp_mb__before_clear_bit(); \
151 		clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
152 		smp_mb__after_clear_bit(); \
153 	} while (0)
154 
155 #define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
156 #define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
157 #define rpc_clear_queued(t)	\
158 	do { \
159 		smp_mb__before_clear_bit(); \
160 		clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
161 		smp_mb__after_clear_bit(); \
162 	} while (0)
163 
164 #define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
165 
166 /*
167  * Task priorities.
168  * Note: if you change these, you must also change
169  * the task initialization definitions below.
170  */
171 #define RPC_PRIORITY_LOW	(-1)
172 #define RPC_PRIORITY_NORMAL	(0)
173 #define RPC_PRIORITY_HIGH	(1)
174 #define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_HIGH - RPC_PRIORITY_LOW)
175 
176 struct rpc_timer {
177 	struct timer_list timer;
178 	struct list_head list;
179 	unsigned long expires;
180 };
181 
182 /*
183  * RPC synchronization objects
184  */
185 struct rpc_wait_queue {
186 	spinlock_t		lock;
187 	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
188 	pid_t			owner;			/* process id of last task serviced */
189 	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
190 	unsigned char		priority;		/* current priority */
191 	unsigned char		count;			/* # task groups remaining serviced so far */
192 	unsigned char		nr;			/* # tasks remaining for cookie */
193 	unsigned short		qlen;			/* total # tasks waiting in queue */
194 	struct rpc_timer	timer_list;
195 #ifdef RPC_DEBUG
196 	const char *		name;
197 #endif
198 };
199 
200 /*
201  * This is the # requests to send consecutively
202  * from a single cookie.  The aim is to improve
203  * performance of NFS operations such as read/write.
204  */
205 #define RPC_BATCH_COUNT			16
206 #define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
207 
208 /*
209  * Function prototypes
210  */
211 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
212 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
213 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
214 				const struct rpc_call_ops *ops);
215 void		rpc_put_task(struct rpc_task *);
216 void		rpc_exit_task(struct rpc_task *);
217 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
218 void		rpc_killall_tasks(struct rpc_clnt *);
219 void		rpc_execute(struct rpc_task *);
220 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
221 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
222 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
223 void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
224 					rpc_action action);
225 void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
226 					struct rpc_task *);
227 void		rpc_wake_up(struct rpc_wait_queue *);
228 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
229 void		rpc_wake_up_status(struct rpc_wait_queue *, int);
230 void		rpc_delay(struct rpc_task *, unsigned long);
231 void *		rpc_malloc(struct rpc_task *, size_t);
232 void		rpc_free(void *);
233 int		rpciod_up(void);
234 void		rpciod_down(void);
235 int		__rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
236 #ifdef RPC_DEBUG
237 void		rpc_show_tasks(void);
238 #endif
239 int		rpc_init_mempool(void);
240 void		rpc_destroy_mempool(void);
241 extern struct workqueue_struct *rpciod_workqueue;
242 void		rpc_prepare_task(struct rpc_task *task);
243 
244 static inline void rpc_exit(struct rpc_task *task, int status)
245 {
246 	task->tk_status = status;
247 	task->tk_action = rpc_exit_task;
248 }
249 
250 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
251 {
252 	return __rpc_wait_for_completion_task(task, NULL);
253 }
254 
255 #ifdef RPC_DEBUG
256 static inline const char * rpc_qname(struct rpc_wait_queue *q)
257 {
258 	return ((q && q->name) ? q->name : "unknown");
259 }
260 #endif
261 
262 #endif /* _LINUX_SUNRPC_SCHED_H_ */
263