1 /*
2 * linux/include/linux/sunrpc/sched.h
3 *
4 * Scheduling primitives for kernel Sun RPC.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
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.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 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 struct list_head tk_task; /* global list of tasks */
46 struct rpc_clnt * tk_client; /* RPC client */
47 struct rpc_rqst * tk_rqstp; /* RPC request */
48
49 /*
50 * RPC call state
51 */
52 struct rpc_message tk_msg; /* RPC call info */
53
54 /*
55 * callback to be executed after waking up
56 * action next procedure for async tasks
57 * tk_ops caller callbacks
58 */
59 void (*tk_callback)(struct rpc_task *);
60 void (*tk_action)(struct rpc_task *);
61 const struct rpc_call_ops *tk_ops;
62 void * tk_calldata;
63
64 unsigned long tk_timeout; /* timeout for rpc_sleep() */
65 unsigned long tk_runstate; /* Task run status */
66 struct workqueue_struct *tk_workqueue; /* Normally rpciod, but could
67 * be any workqueue
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 ktime_t tk_start; /* RPC task init timestamp */
76
77 pid_t tk_owner; /* Process id for batching tasks */
78 int tk_status; /* result of last operation */
79 unsigned short tk_flags; /* misc flags */
80 unsigned short tk_timeouts; /* maj timeouts */
81
82 #ifdef RPC_DEBUG
83 unsigned short tk_pid; /* debugging aid */
84 #endif
85 unsigned char tk_priority : 2,/* Task priority */
86 tk_garb_retry : 2,
87 tk_cred_retry : 2;
88 };
89 #define tk_xprt tk_client->cl_xprt
90
91 /* support walking a list of tasks on a wait queue */
92 #define task_for_each(task, pos, head) \
93 list_for_each(pos, head) \
94 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
95
96 #define task_for_first(task, head) \
97 if (!list_empty(head) && \
98 ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
99
100 typedef void (*rpc_action)(struct rpc_task *);
101
102 struct rpc_call_ops {
103 void (*rpc_call_prepare)(struct rpc_task *, void *);
104 void (*rpc_call_done)(struct rpc_task *, void *);
105 void (*rpc_release)(void *);
106 };
107
108 struct rpc_task_setup {
109 struct rpc_task *task;
110 struct rpc_clnt *rpc_client;
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_CALL_MAJORSEEN 0x0020 /* major timeout seen */
125 #define RPC_TASK_ROOTCREDS 0x0040 /* force root creds */
126 #define RPC_TASK_DYNAMIC 0x0080 /* task was kmalloc'ed */
127 #define RPC_TASK_KILLED 0x0100 /* task was killed */
128 #define RPC_TASK_SOFT 0x0200 /* Use soft timeouts */
129 #define RPC_TASK_SOFTCONN 0x0400 /* Fail if can't connect */
130 #define RPC_TASK_SENT 0x0800 /* message was sent */
131 #define RPC_TASK_TIMEOUT 0x1000 /* fail with ETIMEDOUT on timeout */
132
133 #define RPC_IS_ASYNC(t) ((t)->tk_flags & RPC_TASK_ASYNC)
134 #define RPC_IS_SWAPPER(t) ((t)->tk_flags & RPC_TASK_SWAPPER)
135 #define RPC_DO_ROOTOVERRIDE(t) ((t)->tk_flags & RPC_TASK_ROOTCREDS)
136 #define RPC_ASSASSINATED(t) ((t)->tk_flags & RPC_TASK_KILLED)
137 #define RPC_IS_SOFT(t) ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
138 #define RPC_IS_SOFTCONN(t) ((t)->tk_flags & RPC_TASK_SOFTCONN)
139 #define RPC_WAS_SENT(t) ((t)->tk_flags & RPC_TASK_SENT)
140
141 #define RPC_TASK_RUNNING 0
142 #define RPC_TASK_QUEUED 1
143 #define RPC_TASK_ACTIVE 2
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_clear_bit(); \
152 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
153 smp_mb__after_clear_bit(); \
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_clear_bit(); \
161 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
162 smp_mb__after_clear_bit(); \
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 count; /* # task groups remaining serviced so far */
194 unsigned char nr; /* # tasks remaining for cookie */
195 unsigned short qlen; /* total # tasks waiting in queue */
196 struct rpc_timer timer_list;
197 #ifdef RPC_DEBUG
198 const char * name;
199 #endif
200 };
201
202 /*
203 * This is the # requests to send consecutively
204 * from a single cookie. The aim is to improve
205 * performance of NFS operations such as read/write.
206 */
207 #define RPC_BATCH_COUNT 16
208 #define RPC_IS_PRIORITY(q) ((q)->maxpriority > 0)
209
210 /*
211 * Function prototypes
212 */
213 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
214 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
215 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
216 const struct rpc_call_ops *ops);
217 void rpc_put_task(struct rpc_task *);
218 void rpc_put_task_async(struct rpc_task *);
219 void rpc_exit_task(struct rpc_task *);
220 void rpc_exit(struct rpc_task *, int);
221 void rpc_release_calldata(const struct rpc_call_ops *, void *);
222 void rpc_killall_tasks(struct rpc_clnt *);
223 void rpc_execute(struct rpc_task *);
224 void rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
225 void rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
226 void rpc_destroy_wait_queue(struct rpc_wait_queue *);
227 void rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
228 rpc_action action);
229 void rpc_wake_up_queued_task(struct rpc_wait_queue *,
230 struct rpc_task *);
231 void rpc_wake_up(struct rpc_wait_queue *);
232 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
233 void rpc_wake_up_status(struct rpc_wait_queue *, int);
234 int rpc_queue_empty(struct rpc_wait_queue *);
235 void rpc_delay(struct rpc_task *, unsigned long);
236 void * rpc_malloc(struct rpc_task *, size_t);
237 void rpc_free(void *);
238 int rpciod_up(void);
239 void rpciod_down(void);
240 int __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
241 #ifdef RPC_DEBUG
242 void rpc_show_tasks(void);
243 #endif
244 int rpc_init_mempool(void);
245 void rpc_destroy_mempool(void);
246 extern struct workqueue_struct *rpciod_workqueue;
247 void rpc_prepare_task(struct rpc_task *task);
248
rpc_wait_for_completion_task(struct rpc_task * task)249 static inline int rpc_wait_for_completion_task(struct rpc_task *task)
250 {
251 return __rpc_wait_for_completion_task(task, NULL);
252 }
253
rpc_task_set_priority(struct rpc_task * task,unsigned char prio)254 static inline void rpc_task_set_priority(struct rpc_task *task, unsigned char prio)
255 {
256 task->tk_priority = prio - RPC_PRIORITY_LOW;
257 }
258
rpc_task_has_priority(struct rpc_task * task,unsigned char prio)259 static inline int rpc_task_has_priority(struct rpc_task *task, unsigned char prio)
260 {
261 return (task->tk_priority + RPC_PRIORITY_LOW == prio);
262 }
263
264 #ifdef RPC_DEBUG
rpc_qname(struct rpc_wait_queue * q)265 static inline const char * rpc_qname(struct rpc_wait_queue *q)
266 {
267 return ((q && q->name) ? q->name : "unknown");
268 }
269 #endif
270
271 #endif /* _LINUX_SUNRPC_SCHED_H_ */
272