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8b712842 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
08a9ff32 | 3 | * Copyright (C) 2014 Fujitsu. All rights reserved. |
8b712842 CM |
4 | * |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public | |
7 | * License v2 as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public | |
15 | * License along with this program; if not, write to the | |
16 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
17 | * Boston, MA 021110-1307, USA. | |
18 | */ | |
19 | ||
20 | #include <linux/kthread.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
8b712842 CM |
22 | #include <linux/list.h> |
23 | #include <linux/spinlock.h> | |
b51912c9 | 24 | #include <linux/freezer.h> |
8b712842 | 25 | #include "async-thread.h" |
52483bc2 | 26 | #include "ctree.h" |
8b712842 | 27 | |
a046e9c8 QW |
28 | #define WORK_DONE_BIT 0 |
29 | #define WORK_ORDER_DONE_BIT 1 | |
30 | #define WORK_HIGH_PRIO_BIT 2 | |
4a69a410 | 31 | |
0bd9289c QW |
32 | #define NO_THRESHOLD (-1) |
33 | #define DFT_THRESHOLD (32) | |
34 | ||
d458b054 | 35 | struct __btrfs_workqueue { |
08a9ff32 QW |
36 | struct workqueue_struct *normal_wq; |
37 | /* List head pointing to ordered work list */ | |
38 | struct list_head ordered_list; | |
39 | ||
40 | /* Spinlock for ordered_list */ | |
41 | spinlock_t list_lock; | |
0bd9289c QW |
42 | |
43 | /* Thresholding related variants */ | |
44 | atomic_t pending; | |
c6dd6ea5 QW |
45 | |
46 | /* Up limit of concurrency workers */ | |
47 | int limit_active; | |
48 | ||
49 | /* Current number of concurrency workers */ | |
50 | int current_active; | |
51 | ||
52 | /* Threshold to change current_active */ | |
0bd9289c QW |
53 | int thresh; |
54 | unsigned int count; | |
55 | spinlock_t thres_lock; | |
08a9ff32 QW |
56 | }; |
57 | ||
d458b054 QW |
58 | struct btrfs_workqueue { |
59 | struct __btrfs_workqueue *normal; | |
60 | struct __btrfs_workqueue *high; | |
1ca08976 QW |
61 | }; |
62 | ||
9e0af237 LB |
63 | static void normal_work_helper(struct btrfs_work *work); |
64 | ||
65 | #define BTRFS_WORK_HELPER(name) \ | |
66 | void btrfs_##name(struct work_struct *arg) \ | |
67 | { \ | |
68 | struct btrfs_work *work = container_of(arg, struct btrfs_work, \ | |
69 | normal_work); \ | |
70 | normal_work_helper(work); \ | |
71 | } | |
72 | ||
73 | BTRFS_WORK_HELPER(worker_helper); | |
74 | BTRFS_WORK_HELPER(delalloc_helper); | |
75 | BTRFS_WORK_HELPER(flush_delalloc_helper); | |
76 | BTRFS_WORK_HELPER(cache_helper); | |
77 | BTRFS_WORK_HELPER(submit_helper); | |
78 | BTRFS_WORK_HELPER(fixup_helper); | |
79 | BTRFS_WORK_HELPER(endio_helper); | |
80 | BTRFS_WORK_HELPER(endio_meta_helper); | |
81 | BTRFS_WORK_HELPER(endio_meta_write_helper); | |
82 | BTRFS_WORK_HELPER(endio_raid56_helper); | |
8b110e39 | 83 | BTRFS_WORK_HELPER(endio_repair_helper); |
9e0af237 LB |
84 | BTRFS_WORK_HELPER(rmw_helper); |
85 | BTRFS_WORK_HELPER(endio_write_helper); | |
86 | BTRFS_WORK_HELPER(freespace_write_helper); | |
87 | BTRFS_WORK_HELPER(delayed_meta_helper); | |
88 | BTRFS_WORK_HELPER(readahead_helper); | |
89 | BTRFS_WORK_HELPER(qgroup_rescan_helper); | |
90 | BTRFS_WORK_HELPER(extent_refs_helper); | |
91 | BTRFS_WORK_HELPER(scrub_helper); | |
92 | BTRFS_WORK_HELPER(scrubwrc_helper); | |
93 | BTRFS_WORK_HELPER(scrubnc_helper); | |
20b2e302 | 94 | BTRFS_WORK_HELPER(scrubparity_helper); |
9e0af237 LB |
95 | |
96 | static struct __btrfs_workqueue * | |
c6dd6ea5 | 97 | __btrfs_alloc_workqueue(const char *name, unsigned int flags, int limit_active, |
c3a46891 | 98 | int thresh) |
1ca08976 | 99 | { |
61dd5ae6 | 100 | struct __btrfs_workqueue *ret = kzalloc(sizeof(*ret), GFP_KERNEL); |
1ca08976 | 101 | |
5d99a998 | 102 | if (!ret) |
1ca08976 QW |
103 | return NULL; |
104 | ||
c6dd6ea5 | 105 | ret->limit_active = limit_active; |
0bd9289c QW |
106 | atomic_set(&ret->pending, 0); |
107 | if (thresh == 0) | |
108 | thresh = DFT_THRESHOLD; | |
109 | /* For low threshold, disabling threshold is a better choice */ | |
110 | if (thresh < DFT_THRESHOLD) { | |
c6dd6ea5 | 111 | ret->current_active = limit_active; |
0bd9289c QW |
112 | ret->thresh = NO_THRESHOLD; |
113 | } else { | |
c6dd6ea5 QW |
114 | /* |
115 | * For threshold-able wq, let its concurrency grow on demand. | |
116 | * Use minimal max_active at alloc time to reduce resource | |
117 | * usage. | |
118 | */ | |
119 | ret->current_active = 1; | |
0bd9289c QW |
120 | ret->thresh = thresh; |
121 | } | |
122 | ||
1ca08976 QW |
123 | if (flags & WQ_HIGHPRI) |
124 | ret->normal_wq = alloc_workqueue("%s-%s-high", flags, | |
c6dd6ea5 QW |
125 | ret->current_active, "btrfs", |
126 | name); | |
1ca08976 QW |
127 | else |
128 | ret->normal_wq = alloc_workqueue("%s-%s", flags, | |
c6dd6ea5 | 129 | ret->current_active, "btrfs", |
0bd9289c | 130 | name); |
5d99a998 | 131 | if (!ret->normal_wq) { |
1ca08976 QW |
132 | kfree(ret); |
133 | return NULL; | |
134 | } | |
135 | ||
136 | INIT_LIST_HEAD(&ret->ordered_list); | |
137 | spin_lock_init(&ret->list_lock); | |
0bd9289c | 138 | spin_lock_init(&ret->thres_lock); |
c3a46891 | 139 | trace_btrfs_workqueue_alloc(ret, name, flags & WQ_HIGHPRI); |
1ca08976 QW |
140 | return ret; |
141 | } | |
142 | ||
143 | static inline void | |
d458b054 | 144 | __btrfs_destroy_workqueue(struct __btrfs_workqueue *wq); |
1ca08976 | 145 | |
c3a46891 | 146 | struct btrfs_workqueue *btrfs_alloc_workqueue(const char *name, |
6f011058 | 147 | unsigned int flags, |
c6dd6ea5 | 148 | int limit_active, |
d458b054 | 149 | int thresh) |
08a9ff32 | 150 | { |
61dd5ae6 | 151 | struct btrfs_workqueue *ret = kzalloc(sizeof(*ret), GFP_KERNEL); |
08a9ff32 | 152 | |
5d99a998 | 153 | if (!ret) |
08a9ff32 QW |
154 | return NULL; |
155 | ||
1ca08976 | 156 | ret->normal = __btrfs_alloc_workqueue(name, flags & ~WQ_HIGHPRI, |
c6dd6ea5 | 157 | limit_active, thresh); |
5d99a998 | 158 | if (!ret->normal) { |
08a9ff32 QW |
159 | kfree(ret); |
160 | return NULL; | |
161 | } | |
162 | ||
1ca08976 | 163 | if (flags & WQ_HIGHPRI) { |
c6dd6ea5 | 164 | ret->high = __btrfs_alloc_workqueue(name, flags, limit_active, |
0bd9289c | 165 | thresh); |
5d99a998 | 166 | if (!ret->high) { |
1ca08976 QW |
167 | __btrfs_destroy_workqueue(ret->normal); |
168 | kfree(ret); | |
169 | return NULL; | |
170 | } | |
171 | } | |
08a9ff32 QW |
172 | return ret; |
173 | } | |
174 | ||
0bd9289c QW |
175 | /* |
176 | * Hook for threshold which will be called in btrfs_queue_work. | |
177 | * This hook WILL be called in IRQ handler context, | |
178 | * so workqueue_set_max_active MUST NOT be called in this hook | |
179 | */ | |
d458b054 | 180 | static inline void thresh_queue_hook(struct __btrfs_workqueue *wq) |
0bd9289c QW |
181 | { |
182 | if (wq->thresh == NO_THRESHOLD) | |
183 | return; | |
184 | atomic_inc(&wq->pending); | |
185 | } | |
186 | ||
187 | /* | |
188 | * Hook for threshold which will be called before executing the work, | |
189 | * This hook is called in kthread content. | |
190 | * So workqueue_set_max_active is called here. | |
191 | */ | |
d458b054 | 192 | static inline void thresh_exec_hook(struct __btrfs_workqueue *wq) |
0bd9289c | 193 | { |
c6dd6ea5 | 194 | int new_current_active; |
0bd9289c QW |
195 | long pending; |
196 | int need_change = 0; | |
197 | ||
198 | if (wq->thresh == NO_THRESHOLD) | |
199 | return; | |
200 | ||
201 | atomic_dec(&wq->pending); | |
202 | spin_lock(&wq->thres_lock); | |
203 | /* | |
204 | * Use wq->count to limit the calling frequency of | |
205 | * workqueue_set_max_active. | |
206 | */ | |
207 | wq->count++; | |
208 | wq->count %= (wq->thresh / 4); | |
209 | if (!wq->count) | |
210 | goto out; | |
c6dd6ea5 | 211 | new_current_active = wq->current_active; |
0bd9289c QW |
212 | |
213 | /* | |
214 | * pending may be changed later, but it's OK since we really | |
215 | * don't need it so accurate to calculate new_max_active. | |
216 | */ | |
217 | pending = atomic_read(&wq->pending); | |
218 | if (pending > wq->thresh) | |
c6dd6ea5 | 219 | new_current_active++; |
0bd9289c | 220 | if (pending < wq->thresh / 2) |
c6dd6ea5 QW |
221 | new_current_active--; |
222 | new_current_active = clamp_val(new_current_active, 1, wq->limit_active); | |
223 | if (new_current_active != wq->current_active) { | |
0bd9289c | 224 | need_change = 1; |
c6dd6ea5 | 225 | wq->current_active = new_current_active; |
0bd9289c QW |
226 | } |
227 | out: | |
228 | spin_unlock(&wq->thres_lock); | |
229 | ||
230 | if (need_change) { | |
c6dd6ea5 | 231 | workqueue_set_max_active(wq->normal_wq, wq->current_active); |
0bd9289c QW |
232 | } |
233 | } | |
234 | ||
d458b054 | 235 | static void run_ordered_work(struct __btrfs_workqueue *wq) |
08a9ff32 QW |
236 | { |
237 | struct list_head *list = &wq->ordered_list; | |
d458b054 | 238 | struct btrfs_work *work; |
08a9ff32 QW |
239 | spinlock_t *lock = &wq->list_lock; |
240 | unsigned long flags; | |
241 | ||
242 | while (1) { | |
243 | spin_lock_irqsave(lock, flags); | |
244 | if (list_empty(list)) | |
245 | break; | |
d458b054 | 246 | work = list_entry(list->next, struct btrfs_work, |
08a9ff32 QW |
247 | ordered_list); |
248 | if (!test_bit(WORK_DONE_BIT, &work->flags)) | |
249 | break; | |
250 | ||
251 | /* | |
252 | * we are going to call the ordered done function, but | |
253 | * we leave the work item on the list as a barrier so | |
254 | * that later work items that are done don't have their | |
255 | * functions called before this one returns | |
256 | */ | |
257 | if (test_and_set_bit(WORK_ORDER_DONE_BIT, &work->flags)) | |
258 | break; | |
52483bc2 | 259 | trace_btrfs_ordered_sched(work); |
08a9ff32 QW |
260 | spin_unlock_irqrestore(lock, flags); |
261 | work->ordered_func(work); | |
262 | ||
263 | /* now take the lock again and drop our item from the list */ | |
264 | spin_lock_irqsave(lock, flags); | |
265 | list_del(&work->ordered_list); | |
266 | spin_unlock_irqrestore(lock, flags); | |
267 | ||
268 | /* | |
269 | * we don't want to call the ordered free functions | |
270 | * with the lock held though | |
271 | */ | |
272 | work->ordered_free(work); | |
52483bc2 | 273 | trace_btrfs_all_work_done(work); |
08a9ff32 QW |
274 | } |
275 | spin_unlock_irqrestore(lock, flags); | |
276 | } | |
277 | ||
9e0af237 | 278 | static void normal_work_helper(struct btrfs_work *work) |
08a9ff32 | 279 | { |
d458b054 | 280 | struct __btrfs_workqueue *wq; |
08a9ff32 QW |
281 | int need_order = 0; |
282 | ||
08a9ff32 QW |
283 | /* |
284 | * We should not touch things inside work in the following cases: | |
285 | * 1) after work->func() if it has no ordered_free | |
286 | * Since the struct is freed in work->func(). | |
287 | * 2) after setting WORK_DONE_BIT | |
288 | * The work may be freed in other threads almost instantly. | |
289 | * So we save the needed things here. | |
290 | */ | |
291 | if (work->ordered_func) | |
292 | need_order = 1; | |
293 | wq = work->wq; | |
294 | ||
52483bc2 | 295 | trace_btrfs_work_sched(work); |
0bd9289c | 296 | thresh_exec_hook(wq); |
08a9ff32 QW |
297 | work->func(work); |
298 | if (need_order) { | |
299 | set_bit(WORK_DONE_BIT, &work->flags); | |
300 | run_ordered_work(wq); | |
301 | } | |
52483bc2 QW |
302 | if (!need_order) |
303 | trace_btrfs_all_work_done(work); | |
08a9ff32 QW |
304 | } |
305 | ||
9e0af237 | 306 | void btrfs_init_work(struct btrfs_work *work, btrfs_work_func_t uniq_func, |
6db8914f QW |
307 | btrfs_func_t func, |
308 | btrfs_func_t ordered_func, | |
309 | btrfs_func_t ordered_free) | |
08a9ff32 QW |
310 | { |
311 | work->func = func; | |
312 | work->ordered_func = ordered_func; | |
313 | work->ordered_free = ordered_free; | |
9e0af237 | 314 | INIT_WORK(&work->normal_work, uniq_func); |
08a9ff32 QW |
315 | INIT_LIST_HEAD(&work->ordered_list); |
316 | work->flags = 0; | |
317 | } | |
318 | ||
d458b054 QW |
319 | static inline void __btrfs_queue_work(struct __btrfs_workqueue *wq, |
320 | struct btrfs_work *work) | |
08a9ff32 QW |
321 | { |
322 | unsigned long flags; | |
323 | ||
324 | work->wq = wq; | |
0bd9289c | 325 | thresh_queue_hook(wq); |
08a9ff32 QW |
326 | if (work->ordered_func) { |
327 | spin_lock_irqsave(&wq->list_lock, flags); | |
328 | list_add_tail(&work->ordered_list, &wq->ordered_list); | |
329 | spin_unlock_irqrestore(&wq->list_lock, flags); | |
330 | } | |
52483bc2 | 331 | trace_btrfs_work_queued(work); |
0a95b851 | 332 | queue_work(wq->normal_wq, &work->normal_work); |
08a9ff32 QW |
333 | } |
334 | ||
d458b054 QW |
335 | void btrfs_queue_work(struct btrfs_workqueue *wq, |
336 | struct btrfs_work *work) | |
1ca08976 | 337 | { |
d458b054 | 338 | struct __btrfs_workqueue *dest_wq; |
1ca08976 QW |
339 | |
340 | if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags) && wq->high) | |
341 | dest_wq = wq->high; | |
342 | else | |
343 | dest_wq = wq->normal; | |
344 | __btrfs_queue_work(dest_wq, work); | |
345 | } | |
346 | ||
347 | static inline void | |
d458b054 | 348 | __btrfs_destroy_workqueue(struct __btrfs_workqueue *wq) |
08a9ff32 QW |
349 | { |
350 | destroy_workqueue(wq->normal_wq); | |
c3a46891 | 351 | trace_btrfs_workqueue_destroy(wq); |
08a9ff32 QW |
352 | kfree(wq); |
353 | } | |
354 | ||
d458b054 | 355 | void btrfs_destroy_workqueue(struct btrfs_workqueue *wq) |
1ca08976 QW |
356 | { |
357 | if (!wq) | |
358 | return; | |
359 | if (wq->high) | |
360 | __btrfs_destroy_workqueue(wq->high); | |
361 | __btrfs_destroy_workqueue(wq->normal); | |
ef66af10 | 362 | kfree(wq); |
1ca08976 QW |
363 | } |
364 | ||
c6dd6ea5 | 365 | void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int limit_active) |
08a9ff32 | 366 | { |
800ee224 ST |
367 | if (!wq) |
368 | return; | |
c6dd6ea5 | 369 | wq->normal->limit_active = limit_active; |
1ca08976 | 370 | if (wq->high) |
c6dd6ea5 | 371 | wq->high->limit_active = limit_active; |
1ca08976 QW |
372 | } |
373 | ||
d458b054 | 374 | void btrfs_set_work_high_priority(struct btrfs_work *work) |
1ca08976 QW |
375 | { |
376 | set_bit(WORK_HIGH_PRIO_BIT, &work->flags); | |
08a9ff32 | 377 | } |