sched.h

  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 */
 24struct rpc_procinfo;
 25struct 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
 32struct rpc_call_ops;
 33struct rpc_wait_queue;
 34struct 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 describes a timeout strategy
 42 */
 43struct rpc_timeout {
 44	unsigned long		to_initval,		/* initial timeout */
 45				to_maxval,		/* max timeout */
 46				to_increment;		/* if !exponential */
 47	unsigned int		to_retries;		/* max # of retries */
 48	unsigned char		to_exponential;
 49};
 50
 51/*
 52 * This is the RPC task struct
 53 */
 54struct rpc_task {
 55	atomic_t		tk_count;	/* Reference count */
 56	int			tk_status;	/* result of last operation */
 57	struct list_head	tk_task;	/* global list of tasks */
 58
 59	/*
 60	 * callback	to be executed after waking up
 61	 * action	next procedure for async tasks
 62	 */
 63	void			(*tk_callback)(struct rpc_task *);
 64	void			(*tk_action)(struct rpc_task *);
 65
 66	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
 67	unsigned long		tk_runstate;	/* Task run status */
 68
 69	struct rpc_wait_queue 	*tk_waitqueue;	/* RPC wait queue we're on */
 70	union {
 71		struct work_struct	tk_work;	/* Async task work queue */
 72		struct rpc_wait		tk_wait;	/* RPC wait */
 73	} u;
 74
 75	/*
 76	 * RPC call state
 77	 */
 78	struct rpc_message	tk_msg;		/* RPC call info */
 79	void *			tk_calldata;	/* Caller private data */
 80	const struct rpc_call_ops *tk_ops;	/* Caller callbacks */
 81
 82	struct rpc_clnt *	tk_client;	/* RPC client */
 83	struct rpc_xprt *	tk_xprt;	/* Transport */
 84	struct rpc_cred *	tk_op_cred;	/* cred being operated on */
 85
 86	struct rpc_rqst *	tk_rqstp;	/* RPC request */
 87
 88	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
 89						 * be any workqueue
 90						 */
 91	ktime_t			tk_start;	/* RPC task init timestamp */
 92
 93	pid_t			tk_owner;	/* Process id for batching tasks */
 94
 95	int			tk_rpc_status;	/* Result of last RPC operation */
 96	unsigned short		tk_flags;	/* misc flags */
 97	unsigned short		tk_timeouts;	/* maj timeouts */
 98
 99#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
100	unsigned short		tk_pid;		/* debugging aid */
101#endif
102	unsigned char		tk_priority : 2,/* Task priority */
103				tk_garb_retry : 2,
104				tk_cred_retry : 2;
105};
106
107typedef void			(*rpc_action)(struct rpc_task *);
108
109struct rpc_call_ops {
110	void (*rpc_call_prepare)(struct rpc_task *, void *);
111	void (*rpc_call_done)(struct rpc_task *, void *);
112	void (*rpc_count_stats)(struct rpc_task *, void *);
113	void (*rpc_release)(void *);
114};
115
116struct rpc_task_setup {
117	struct rpc_task *task;
118	struct rpc_clnt *rpc_client;
119	struct rpc_xprt *rpc_xprt;
120	struct rpc_cred *rpc_op_cred;	/* credential being operated on */
121	const struct rpc_message *rpc_message;
122	const struct rpc_call_ops *callback_ops;
123	void *callback_data;
124	struct workqueue_struct *workqueue;
125	unsigned short flags;
126	signed char priority;
127};
128
129/*
130 * RPC task flags
131 */
132#define RPC_TASK_ASYNC		0x0001		/* is an async task */
133#define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
134#define RPC_TASK_MOVEABLE	0x0004		/* nfs4.1+ rpc tasks */
135#define RPC_TASK_NULLCREDS	0x0010		/* Use AUTH_NULL credential */
136#define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
137#define RPC_TASK_NETUNREACH_FATAL 0x0040	/* ENETUNREACH is fatal */
138#define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
139#define	RPC_TASK_NO_ROUND_ROBIN	0x0100		/* send requests on "main" xprt */
140#define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
141#define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
142#define RPC_TASK_SENT		0x0800		/* message was sent */
143#define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
144#define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
145#define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
146#define RPC_TASK_CRED_NOREF	0x8000		/* No refcount on the credential */
147
148#define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
149#define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
150#define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
151#define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
152#define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
153#define RPC_IS_MOVEABLE(t)	((t)->tk_flags & RPC_TASK_MOVEABLE)
154
155enum {
156	RPC_TASK_RUNNING,
157	RPC_TASK_QUEUED,
158	RPC_TASK_ACTIVE,
159	RPC_TASK_NEED_XMIT,
160	RPC_TASK_NEED_RECV,
161	RPC_TASK_MSG_PIN_WAIT,
162};
163
164#define rpc_test_and_set_running(t) \
165				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
166#define rpc_clear_running(t)	clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
167
168#define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
169#define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
170#define rpc_clear_queued(t)	clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
171
172#define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
173
174#define RPC_SIGNALLED(t)	(READ_ONCE(task->tk_rpc_status) == -ERESTARTSYS)
175
176/*
177 * Task priorities.
178 * Note: if you change these, you must also change
179 * the task initialization definitions below.
180 */
181#define RPC_PRIORITY_LOW	(-1)
182#define RPC_PRIORITY_NORMAL	(0)
183#define RPC_PRIORITY_HIGH	(1)
184#define RPC_PRIORITY_PRIVILEGED	(2)
185#define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
186
187struct rpc_timer {
188	struct list_head list;
189	unsigned long expires;
190	struct delayed_work dwork;
191};
192
193/*
194 * RPC synchronization objects
195 */
196struct rpc_wait_queue {
197	spinlock_t		lock;
198	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
199	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
200	unsigned char		priority;		/* current priority */
201	unsigned char		nr;			/* # tasks remaining for cookie */
202	unsigned int		qlen;			/* total # tasks waiting in queue */
203	struct rpc_timer	timer_list;
204#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
205	const char *		name;
206#endif
207};
208
209/*
210 * This is the # requests to send consecutively
211 * from a single cookie.  The aim is to improve
212 * performance of NFS operations such as read/write.
213 */
214#define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
215
216/*
217 * Function prototypes
218 */
219struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
220struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
221struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
222		struct rpc_timeout *timeout);
223void		rpc_put_task(struct rpc_task *);
224void		rpc_put_task_async(struct rpc_task *);
225bool		rpc_task_set_rpc_status(struct rpc_task *task, int rpc_status);
226void		rpc_task_try_cancel(struct rpc_task *task, int error);
227void		rpc_signal_task(struct rpc_task *);
228void		rpc_exit_task(struct rpc_task *);
229void		rpc_exit(struct rpc_task *, int);
230void		rpc_release_calldata(const struct rpc_call_ops *, void *);
231void		rpc_killall_tasks(struct rpc_clnt *);
232unsigned long	rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
233				 bool (*fnmatch)(const struct rpc_task *,
234						 const void *),
235				 const void *data);
236void		rpc_execute(struct rpc_task *);
237void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
238void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
239void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
240unsigned long	rpc_task_timeout(const struct rpc_task *task);
241void		rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
242					struct rpc_task *task,
243					rpc_action action,
244					unsigned long timeout);
245void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
246					rpc_action action);
247void		rpc_sleep_on_priority_timeout(struct rpc_wait_queue *queue,
248					struct rpc_task *task,
249					unsigned long timeout,
250					int priority);
251void		rpc_sleep_on_priority(struct rpc_wait_queue *,
252					struct rpc_task *,
253					int priority);
254void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
255					struct rpc_task *);
256void		rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
257						   struct rpc_task *,
258						   int);
259void		rpc_wake_up(struct rpc_wait_queue *);
260struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
261struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
262					struct rpc_wait_queue *,
263					bool (*)(struct rpc_task *, void *),
264					void *);
265struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
266					bool (*)(struct rpc_task *, void *),
267					void *);
268void		rpc_wake_up_status(struct rpc_wait_queue *, int);
269void		rpc_delay(struct rpc_task *, unsigned long);
270int		rpc_malloc(struct rpc_task *);
271void		rpc_free(struct rpc_task *);
272int		rpciod_up(void);
273void		rpciod_down(void);
274int		rpc_wait_for_completion_task(struct rpc_task *task);
275#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
276struct net;
277void		rpc_show_tasks(struct net *);
278#endif
279int		rpc_init_mempool(void);
280void		rpc_destroy_mempool(void);
281extern struct workqueue_struct *rpciod_workqueue;
282extern struct workqueue_struct *xprtiod_workqueue;
283void		rpc_prepare_task(struct rpc_task *task);
284gfp_t		rpc_task_gfp_mask(void);
285
286#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
287static inline const char * rpc_qname(const struct rpc_wait_queue *q)
288{
289	return ((q && q->name) ? q->name : "unknown");
290}
291
292static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
293		const char *name)
294{
295	q->name = name;
296}
297#else
298static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
299		const char *name)
300{
301}
302#endif
303
304#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
305int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
306void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
307#else
308static inline int
309rpc_clnt_swap_activate(struct rpc_clnt *clnt)
310{
311	return -EINVAL;
312}
313
314static inline void
315rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
316{
317}
318#endif /* CONFIG_SUNRPC_SWAP */
319
320#endif /* _LINUX_SUNRPC_SCHED_H_ */