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8#include <linux/debugfs.h>
9#include <linux/module.h>
10#include <linux/seq_file.h>
11
12#include "closure.h"
13
14void closure_queue(struct closure *cl)
15{
16 struct workqueue_struct *wq = cl->wq;
17 if (wq) {
18 INIT_WORK(&cl->work, cl->work.func);
19 BUG_ON(!queue_work(wq, &cl->work));
20 } else
21 cl->fn(cl);
22}
23EXPORT_SYMBOL_GPL(closure_queue);
24
25#define CL_FIELD(type, field) \
26 case TYPE_ ## type: \
27 return &container_of(cl, struct type, cl)->field
28
29static struct closure_waitlist *closure_waitlist(struct closure *cl)
30{
31 switch (cl->type) {
32 CL_FIELD(closure_with_waitlist, wait);
33 CL_FIELD(closure_with_waitlist_and_timer, wait);
34 default:
35 return NULL;
36 }
37}
38
39static struct timer_list *closure_timer(struct closure *cl)
40{
41 switch (cl->type) {
42 CL_FIELD(closure_with_timer, timer);
43 CL_FIELD(closure_with_waitlist_and_timer, timer);
44 default:
45 return NULL;
46 }
47}
48
49static inline void closure_put_after_sub(struct closure *cl, int flags)
50{
51 int r = flags & CLOSURE_REMAINING_MASK;
52
53 BUG_ON(flags & CLOSURE_GUARD_MASK);
54 BUG_ON(!r && (flags & ~(CLOSURE_DESTRUCTOR|CLOSURE_BLOCKING)));
55
56
57 if (r == 1 && (flags & CLOSURE_SLEEPING))
58 wake_up_process(cl->task);
59
60 if (!r) {
61 if (cl->fn && !(flags & CLOSURE_DESTRUCTOR)) {
62
63 atomic_set(&cl->remaining,
64 CLOSURE_REMAINING_INITIALIZER);
65 closure_queue(cl);
66 } else {
67 struct closure *parent = cl->parent;
68 struct closure_waitlist *wait = closure_waitlist(cl);
69 closure_fn *destructor = cl->fn;
70
71 closure_debug_destroy(cl);
72
73 smp_mb();
74 atomic_set(&cl->remaining, -1);
75
76 if (wait)
77 closure_wake_up(wait);
78
79 if (destructor)
80 destructor(cl);
81
82 if (parent)
83 closure_put(parent);
84 }
85 }
86}
87
88
89void closure_sub(struct closure *cl, int v)
90{
91 closure_put_after_sub(cl, atomic_sub_return(v, &cl->remaining));
92}
93EXPORT_SYMBOL_GPL(closure_sub);
94
95void closure_put(struct closure *cl)
96{
97 closure_put_after_sub(cl, atomic_dec_return(&cl->remaining));
98}
99EXPORT_SYMBOL_GPL(closure_put);
100
101static void set_waiting(struct closure *cl, unsigned long f)
102{
103#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
104 cl->waiting_on = f;
105#endif
106}
107
108void __closure_wake_up(struct closure_waitlist *wait_list)
109{
110 struct llist_node *list;
111 struct closure *cl;
112 struct llist_node *reverse = NULL;
113
114 list = llist_del_all(&wait_list->list);
115
116
117
118 while (list) {
119 struct llist_node *t = list;
120 list = llist_next(list);
121
122 t->next = reverse;
123 reverse = t;
124 }
125
126
127
128 while (reverse) {
129 cl = container_of(reverse, struct closure, list);
130 reverse = llist_next(reverse);
131
132 set_waiting(cl, 0);
133 closure_sub(cl, CLOSURE_WAITING + 1);
134 }
135}
136EXPORT_SYMBOL_GPL(__closure_wake_up);
137
138bool closure_wait(struct closure_waitlist *list, struct closure *cl)
139{
140 if (atomic_read(&cl->remaining) & CLOSURE_WAITING)
141 return false;
142
143 set_waiting(cl, _RET_IP_);
144 atomic_add(CLOSURE_WAITING + 1, &cl->remaining);
145 llist_add(&cl->list, &list->list);
146
147 return true;
148}
149EXPORT_SYMBOL_GPL(closure_wait);
150
151
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153
154
155
156
157void closure_sync(struct closure *cl)
158{
159 while (1) {
160 __closure_start_sleep(cl);
161 closure_set_ret_ip(cl);
162
163 if ((atomic_read(&cl->remaining) &
164 CLOSURE_REMAINING_MASK) == 1)
165 break;
166
167 schedule();
168 }
169
170 __closure_end_sleep(cl);
171}
172EXPORT_SYMBOL_GPL(closure_sync);
173
174
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177
178
179
180bool closure_trylock(struct closure *cl, struct closure *parent)
181{
182 if (atomic_cmpxchg(&cl->remaining, -1,
183 CLOSURE_REMAINING_INITIALIZER) != -1)
184 return false;
185
186 closure_set_ret_ip(cl);
187
188 smp_mb();
189 cl->parent = parent;
190 if (parent)
191 closure_get(parent);
192
193 closure_debug_create(cl);
194 return true;
195}
196EXPORT_SYMBOL_GPL(closure_trylock);
197
198void __closure_lock(struct closure *cl, struct closure *parent,
199 struct closure_waitlist *wait_list)
200{
201 struct closure wait;
202 closure_init_stack(&wait);
203
204 while (1) {
205 if (closure_trylock(cl, parent))
206 return;
207
208 closure_wait_event_sync(wait_list, &wait,
209 atomic_read(&cl->remaining) == -1);
210 }
211}
212EXPORT_SYMBOL_GPL(__closure_lock);
213
214static void closure_delay_timer_fn(unsigned long data)
215{
216 struct closure *cl = (struct closure *) data;
217 closure_sub(cl, CLOSURE_TIMER + 1);
218}
219
220void do_closure_timer_init(struct closure *cl)
221{
222 struct timer_list *timer = closure_timer(cl);
223
224 init_timer(timer);
225 timer->data = (unsigned long) cl;
226 timer->function = closure_delay_timer_fn;
227}
228EXPORT_SYMBOL_GPL(do_closure_timer_init);
229
230bool __closure_delay(struct closure *cl, unsigned long delay,
231 struct timer_list *timer)
232{
233 if (atomic_read(&cl->remaining) & CLOSURE_TIMER)
234 return false;
235
236 BUG_ON(timer_pending(timer));
237
238 timer->expires = jiffies + delay;
239
240 atomic_add(CLOSURE_TIMER + 1, &cl->remaining);
241 add_timer(timer);
242 return true;
243}
244EXPORT_SYMBOL_GPL(__closure_delay);
245
246void __closure_flush(struct closure *cl, struct timer_list *timer)
247{
248 if (del_timer(timer))
249 closure_sub(cl, CLOSURE_TIMER + 1);
250}
251EXPORT_SYMBOL_GPL(__closure_flush);
252
253void __closure_flush_sync(struct closure *cl, struct timer_list *timer)
254{
255 if (del_timer_sync(timer))
256 closure_sub(cl, CLOSURE_TIMER + 1);
257}
258EXPORT_SYMBOL_GPL(__closure_flush_sync);
259
260#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
261
262static LIST_HEAD(closure_list);
263static DEFINE_SPINLOCK(closure_list_lock);
264
265void closure_debug_create(struct closure *cl)
266{
267 unsigned long flags;
268
269 BUG_ON(cl->magic == CLOSURE_MAGIC_ALIVE);
270 cl->magic = CLOSURE_MAGIC_ALIVE;
271
272 spin_lock_irqsave(&closure_list_lock, flags);
273 list_add(&cl->all, &closure_list);
274 spin_unlock_irqrestore(&closure_list_lock, flags);
275}
276EXPORT_SYMBOL_GPL(closure_debug_create);
277
278void closure_debug_destroy(struct closure *cl)
279{
280 unsigned long flags;
281
282 BUG_ON(cl->magic != CLOSURE_MAGIC_ALIVE);
283 cl->magic = CLOSURE_MAGIC_DEAD;
284
285 spin_lock_irqsave(&closure_list_lock, flags);
286 list_del(&cl->all);
287 spin_unlock_irqrestore(&closure_list_lock, flags);
288}
289EXPORT_SYMBOL_GPL(closure_debug_destroy);
290
291static struct dentry *debug;
292
293#define work_data_bits(work) ((unsigned long *)(&(work)->data))
294
295static int debug_seq_show(struct seq_file *f, void *data)
296{
297 struct closure *cl;
298 spin_lock_irq(&closure_list_lock);
299
300 list_for_each_entry(cl, &closure_list, all) {
301 int r = atomic_read(&cl->remaining);
302
303 seq_printf(f, "%p: %pF -> %pf p %p r %i ",
304 cl, (void *) cl->ip, cl->fn, cl->parent,
305 r & CLOSURE_REMAINING_MASK);
306
307 seq_printf(f, "%s%s%s%s%s%s\n",
308 test_bit(WORK_STRUCT_PENDING,
309 work_data_bits(&cl->work)) ? "Q" : "",
310 r & CLOSURE_RUNNING ? "R" : "",
311 r & CLOSURE_BLOCKING ? "B" : "",
312 r & CLOSURE_STACK ? "S" : "",
313 r & CLOSURE_SLEEPING ? "Sl" : "",
314 r & CLOSURE_TIMER ? "T" : "");
315
316 if (r & CLOSURE_WAITING)
317 seq_printf(f, " W %pF\n",
318 (void *) cl->waiting_on);
319
320 seq_printf(f, "\n");
321 }
322
323 spin_unlock_irq(&closure_list_lock);
324 return 0;
325}
326
327static int debug_seq_open(struct inode *inode, struct file *file)
328{
329 return single_open(file, debug_seq_show, NULL);
330}
331
332static const struct file_operations debug_ops = {
333 .owner = THIS_MODULE,
334 .open = debug_seq_open,
335 .read = seq_read,
336 .release = single_release
337};
338
339void __init closure_debug_init(void)
340{
341 debug = debugfs_create_file("closures", 0400, NULL, NULL, &debug_ops);
342}
343
344#endif
345
346MODULE_AUTHOR("Kent Overstreet <koverstreet@google.com>");
347MODULE_LICENSE("GPL");
348
