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/sunrpc/types.h> 14 #include <linux/rcupdate.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 rpc_wait_queue * rpc_waitq; /* RPC wait queue we're on */ 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 unsigned long tk_cookie; /* Cookie for batching tasks */ 60 61 /* 62 * timeout_fn to be executed by timer bottom half 63 * callback to be executed after waking up 64 * action next procedure for async tasks 65 * tk_ops caller callbacks 66 */ 67 void (*tk_timeout_fn)(struct rpc_task *); 68 void (*tk_callback)(struct rpc_task *); 69 void (*tk_action)(struct rpc_task *); 70 const struct rpc_call_ops *tk_ops; 71 void * tk_calldata; 72 73 /* 74 * tk_timer is used for async processing by the RPC scheduling 75 * primitives. You should not access this directly unless 76 * you have a pathological interest in kernel oopses. 77 */ 78 struct timer_list tk_timer; /* kernel timer */ 79 unsigned long tk_timeout; /* timeout for rpc_sleep() */ 80 unsigned short tk_flags; /* misc flags */ 81 unsigned char tk_priority : 2;/* Task priority */ 82 unsigned long tk_runstate; /* Task run status */ 83 struct workqueue_struct *tk_workqueue; /* Normally rpciod, but could 84 * be any workqueue 85 */ 86 union { 87 struct work_struct tk_work; /* Async task work queue */ 88 struct rpc_wait tk_wait; /* RPC wait */ 89 struct rcu_head tk_rcu; /* for task deletion */ 90 } u; 91 92 unsigned short tk_timeouts; /* maj timeouts */ 93 size_t tk_bytes_sent; /* total bytes sent */ 94 unsigned long tk_start; /* RPC task init timestamp */ 95 long tk_rtt; /* round-trip time (jiffies) */ 96 97 #ifdef RPC_DEBUG 98 unsigned short tk_pid; /* debugging aid */ 99 #endif 100 }; 101 #define tk_xprt tk_client->cl_xprt 102 103 /* support walking a list of tasks on a wait queue */ 104 #define task_for_each(task, pos, head) \ 105 list_for_each(pos, head) \ 106 if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1) 107 108 #define task_for_first(task, head) \ 109 if (!list_empty(head) && \ 110 ((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1)) 111 112 typedef void (*rpc_action)(struct rpc_task *); 113 114 struct rpc_call_ops { 115 void (*rpc_call_prepare)(struct rpc_task *, void *); 116 void (*rpc_call_done)(struct rpc_task *, void *); 117 void (*rpc_release)(void *); 118 }; 119 120 121 /* 122 * RPC task flags 123 */ 124 #define RPC_TASK_ASYNC 0x0001 /* is an async task */ 125 #define RPC_TASK_SWAPPER 0x0002 /* is swapping in/out */ 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_KILLED 0x0100 /* task was killed */ 130 #define RPC_TASK_SOFT 0x0200 /* Use soft timeouts */ 131 #define RPC_TASK_NOINTR 0x0400 /* uninterruptible task */ 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_DO_CALLBACK(t) ((t)->tk_callback != NULL) 138 #define RPC_IS_SOFT(t) ((t)->tk_flags & RPC_TASK_SOFT) 139 #define RPC_TASK_UNINTERRUPTIBLE(t) ((t)->tk_flags & RPC_TASK_NOINTR) 140 141 #define RPC_TASK_RUNNING 0 142 #define RPC_TASK_QUEUED 1 143 #define RPC_TASK_WAKEUP 2 144 #define RPC_TASK_HAS_TIMER 3 145 #define RPC_TASK_ACTIVE 4 146 147 #define RPC_IS_RUNNING(t) test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate) 148 #define rpc_set_running(t) set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate) 149 #define rpc_test_and_set_running(t) \ 150 test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate) 151 #define rpc_clear_running(t) \ 152 do { \ 153 smp_mb__before_clear_bit(); \ 154 clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \ 155 smp_mb__after_clear_bit(); \ 156 } while (0) 157 158 #define RPC_IS_QUEUED(t) test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate) 159 #define rpc_set_queued(t) set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate) 160 #define rpc_clear_queued(t) \ 161 do { \ 162 smp_mb__before_clear_bit(); \ 163 clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \ 164 smp_mb__after_clear_bit(); \ 165 } while (0) 166 167 #define rpc_start_wakeup(t) \ 168 (test_and_set_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate) == 0) 169 #define rpc_finish_wakeup(t) \ 170 do { \ 171 smp_mb__before_clear_bit(); \ 172 clear_bit(RPC_TASK_WAKEUP, &(t)->tk_runstate); \ 173 smp_mb__after_clear_bit(); \ 174 } while (0) 175 176 #define RPC_IS_ACTIVATED(t) test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate) 177 178 /* 179 * Task priorities. 180 * Note: if you change these, you must also change 181 * the task initialization definitions below. 182 */ 183 #define RPC_PRIORITY_LOW 0 184 #define RPC_PRIORITY_NORMAL 1 185 #define RPC_PRIORITY_HIGH 2 186 #define RPC_NR_PRIORITY (RPC_PRIORITY_HIGH+1) 187 188 /* 189 * RPC synchronization objects 190 */ 191 struct rpc_wait_queue { 192 spinlock_t lock; 193 struct list_head tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */ 194 unsigned long cookie; /* cookie of last task serviced */ 195 unsigned char maxpriority; /* maximum priority (0 if queue is not a priority queue) */ 196 unsigned char priority; /* current priority */ 197 unsigned char count; /* # task groups remaining serviced so far */ 198 unsigned char nr; /* # tasks remaining for cookie */ 199 unsigned short qlen; /* total # tasks waiting in queue */ 200 #ifdef RPC_DEBUG 201 const char * name; 202 #endif 203 }; 204 205 /* 206 * This is the # requests to send consecutively 207 * from a single cookie. The aim is to improve 208 * performance of NFS operations such as read/write. 209 */ 210 #define RPC_BATCH_COUNT 16 211 212 #ifndef RPC_DEBUG 213 # define RPC_WAITQ_INIT(var,qname) { \ 214 .lock = __SPIN_LOCK_UNLOCKED(var.lock), \ 215 .tasks = { \ 216 [0] = LIST_HEAD_INIT(var.tasks[0]), \ 217 [1] = LIST_HEAD_INIT(var.tasks[1]), \ 218 [2] = LIST_HEAD_INIT(var.tasks[2]), \ 219 }, \ 220 } 221 #else 222 # define RPC_WAITQ_INIT(var,qname) { \ 223 .lock = __SPIN_LOCK_UNLOCKED(var.lock), \ 224 .tasks = { \ 225 [0] = LIST_HEAD_INIT(var.tasks[0]), \ 226 [1] = LIST_HEAD_INIT(var.tasks[1]), \ 227 [2] = LIST_HEAD_INIT(var.tasks[2]), \ 228 }, \ 229 .name = qname, \ 230 } 231 #endif 232 # define RPC_WAITQ(var,qname) struct rpc_wait_queue var = RPC_WAITQ_INIT(var,qname) 233 234 #define RPC_IS_PRIORITY(q) ((q)->maxpriority > 0) 235 236 /* 237 * Function prototypes 238 */ 239 struct rpc_task *rpc_new_task(struct rpc_clnt *, int flags, 240 const struct rpc_call_ops *ops, void *data); 241 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags, 242 const struct rpc_call_ops *ops, void *data); 243 void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, 244 int flags, const struct rpc_call_ops *ops, 245 void *data); 246 void rpc_put_task(struct rpc_task *); 247 void rpc_exit_task(struct rpc_task *); 248 void rpc_release_calldata(const struct rpc_call_ops *, void *); 249 void rpc_killall_tasks(struct rpc_clnt *); 250 void rpc_execute(struct rpc_task *); 251 void rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *); 252 void rpc_init_wait_queue(struct rpc_wait_queue *, const char *); 253 void rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *, 254 rpc_action action, rpc_action timer); 255 void rpc_wake_up_task(struct rpc_task *); 256 void rpc_wake_up(struct rpc_wait_queue *); 257 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *); 258 void rpc_wake_up_status(struct rpc_wait_queue *, int); 259 void rpc_delay(struct rpc_task *, unsigned long); 260 void * rpc_malloc(struct rpc_task *, size_t); 261 void rpc_free(void *); 262 int rpciod_up(void); 263 void rpciod_down(void); 264 int __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *)); 265 #ifdef RPC_DEBUG 266 void rpc_show_tasks(void); 267 #endif 268 int rpc_init_mempool(void); 269 void rpc_destroy_mempool(void); 270 extern struct workqueue_struct *rpciod_workqueue; 271 272 static inline void rpc_exit(struct rpc_task *task, int status) 273 { 274 task->tk_status = status; 275 task->tk_action = rpc_exit_task; 276 } 277 278 static inline int rpc_wait_for_completion_task(struct rpc_task *task) 279 { 280 return __rpc_wait_for_completion_task(task, NULL); 281 } 282 283 #ifdef RPC_DEBUG 284 static inline const char * rpc_qname(struct rpc_wait_queue *q) 285 { 286 return ((q && q->name) ? q->name : "unknown"); 287 } 288 #endif 289 290 #endif /* _LINUX_SUNRPC_SCHED_H_ */ 291