Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * include/linux/backing-dev.h | |
4 | * | |
5 | * low-level device information and state which is propagated up through | |
6 | * to high-level code. | |
7 | */ | |
8 | ||
9 | #ifndef _LINUX_BACKING_DEV_H | |
10 | #define _LINUX_BACKING_DEV_H | |
11 | ||
cf0ca9fe | 12 | #include <linux/kernel.h> |
e4ad08fe | 13 | #include <linux/fs.h> |
03ba3782 | 14 | #include <linux/sched.h> |
68f23b89 | 15 | #include <linux/device.h> |
03ba3782 | 16 | #include <linux/writeback.h> |
66114cad | 17 | #include <linux/backing-dev-defs.h> |
a13f35e8 | 18 | #include <linux/slab.h> |
de1414a6 | 19 | |
e41d12f5 CH |
20 | struct blkcg; |
21 | ||
d03f6cdc JK |
22 | static inline struct backing_dev_info *bdi_get(struct backing_dev_info *bdi) |
23 | { | |
24 | kref_get(&bdi->refcnt); | |
25 | return bdi; | |
26 | } | |
27 | ||
34f8fe50 | 28 | struct backing_dev_info *bdi_get_by_id(u64 id); |
d03f6cdc | 29 | void bdi_put(struct backing_dev_info *bdi); |
b2e8fb6e | 30 | |
7c4cc300 JK |
31 | __printf(2, 3) |
32 | int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...); | |
a93f00b3 | 33 | __printf(2, 0) |
7c4cc300 JK |
34 | int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, |
35 | va_list args); | |
3c5d202b | 36 | void bdi_set_owner(struct backing_dev_info *bdi, struct device *owner); |
b02176f3 TH |
37 | void bdi_unregister(struct backing_dev_info *bdi); |
38 | ||
aef33c2f | 39 | struct backing_dev_info *bdi_alloc(int node_id); |
b02176f3 | 40 | |
9ecf4866 | 41 | void wb_start_background_writeback(struct bdi_writeback *wb); |
f0054bb1 | 42 | void wb_workfn(struct work_struct *work); |
f0054bb1 | 43 | void wb_wakeup_delayed(struct bdi_writeback *wb); |
cf0ca9fe | 44 | |
5b9cce4c TH |
45 | void wb_wait_for_completion(struct wb_completion *done); |
46 | ||
03ba3782 | 47 | extern spinlock_t bdi_lock; |
66f3b8e2 JA |
48 | extern struct list_head bdi_list; |
49 | ||
839a8e86 | 50 | extern struct workqueue_struct *bdi_wq; |
d3f77dfd | 51 | extern struct workqueue_struct *bdi_async_bio_wq; |
839a8e86 | 52 | |
d6c10f1f | 53 | static inline bool wb_has_dirty_io(struct bdi_writeback *wb) |
03ba3782 | 54 | { |
d6c10f1f | 55 | return test_bit(WB_has_dirty_io, &wb->state); |
03ba3782 JA |
56 | } |
57 | ||
95a46c65 TH |
58 | static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi) |
59 | { | |
60 | /* | |
61 | * @bdi->tot_write_bandwidth is guaranteed to be > 0 if there are | |
62 | * any dirty wbs. See wb_update_write_bandwidth(). | |
63 | */ | |
64 | return atomic_long_read(&bdi->tot_write_bandwidth); | |
03ba3782 JA |
65 | } |
66 | ||
bd3488e7 | 67 | static inline void wb_stat_mod(struct bdi_writeback *wb, |
93f78d88 | 68 | enum wb_stat_item item, s64 amount) |
b2e8fb6e | 69 | { |
104b4e51 | 70 | percpu_counter_add_batch(&wb->stat[item], amount, WB_STAT_BATCH); |
b2e8fb6e PZ |
71 | } |
72 | ||
93f78d88 | 73 | static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e | 74 | { |
bd3488e7 | 75 | wb_stat_mod(wb, item, 1); |
b2e8fb6e PZ |
76 | } |
77 | ||
93f78d88 | 78 | static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e | 79 | { |
bd3488e7 | 80 | wb_stat_mod(wb, item, -1); |
b2e8fb6e PZ |
81 | } |
82 | ||
93f78d88 | 83 | static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e | 84 | { |
93f78d88 | 85 | return percpu_counter_read_positive(&wb->stat[item]); |
b2e8fb6e PZ |
86 | } |
87 | ||
93f78d88 | 88 | static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item) |
e0bf68dd | 89 | { |
e3d3910a | 90 | return percpu_counter_sum_positive(&wb->stat[item]); |
e0bf68dd PZ |
91 | } |
92 | ||
93f78d88 | 93 | extern void wb_writeout_inc(struct bdi_writeback *wb); |
dd5656e5 | 94 | |
b2e8fb6e PZ |
95 | /* |
96 | * maximal error of a stat counter. | |
97 | */ | |
2bce774e | 98 | static inline unsigned long wb_stat_error(void) |
e0bf68dd | 99 | { |
b2e8fb6e | 100 | #ifdef CONFIG_SMP |
93f78d88 | 101 | return nr_cpu_ids * WB_STAT_BATCH; |
b2e8fb6e PZ |
102 | #else |
103 | return 1; | |
104 | #endif | |
e0bf68dd | 105 | } |
1da177e4 | 106 | |
189d3c4a | 107 | int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio); |
a42dde04 | 108 | int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); |
189d3c4a | 109 | |
1da177e4 LT |
110 | /* |
111 | * Flags in backing_dev_info::capability | |
e4ad08fe | 112 | * |
f56753ac CH |
113 | * BDI_CAP_WRITEBACK: Supports dirty page writeback, and dirty pages |
114 | * should contribute to accounting | |
115 | * BDI_CAP_WRITEBACK_ACCT: Automatically account writeback pages | |
116 | * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold | |
1da177e4 | 117 | */ |
f56753ac CH |
118 | #define BDI_CAP_WRITEBACK (1 << 0) |
119 | #define BDI_CAP_WRITEBACK_ACCT (1 << 1) | |
120 | #define BDI_CAP_STRICTLIMIT (1 << 2) | |
e4ad08fe | 121 | |
5129a469 | 122 | extern struct backing_dev_info noop_backing_dev_info; |
1da177e4 | 123 | |
bc05873d TH |
124 | /** |
125 | * writeback_in_progress - determine whether there is writeback in progress | |
126 | * @wb: bdi_writeback of interest | |
127 | * | |
128 | * Determine whether there is writeback waiting to be handled against a | |
129 | * bdi_writeback. | |
130 | */ | |
131 | static inline bool writeback_in_progress(struct bdi_writeback *wb) | |
1da177e4 | 132 | { |
bc05873d | 133 | return test_bit(WB_writeback_running, &wb->state); |
1da177e4 LT |
134 | } |
135 | ||
ccdf7741 | 136 | struct backing_dev_info *inode_to_bdi(struct inode *inode); |
1da177e4 | 137 | |
ec8a6f26 | 138 | static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) |
1da177e4 | 139 | { |
8c911f3d | 140 | return wb->congested & cong_bits; |
1da177e4 | 141 | } |
373c0a7e | 142 | |
8aa7e847 | 143 | long congestion_wait(int sync, long timeout); |
1da177e4 | 144 | |
f56753ac | 145 | static inline bool mapping_can_writeback(struct address_space *mapping) |
e4ad08fe | 146 | { |
f56753ac | 147 | return inode_to_bdi(mapping->host)->capabilities & BDI_CAP_WRITEBACK; |
e4ad08fe | 148 | } |
1da177e4 | 149 | |
03ba3782 JA |
150 | static inline int bdi_sched_wait(void *word) |
151 | { | |
152 | schedule(); | |
153 | return 0; | |
154 | } | |
155 | ||
89e9b9e0 TH |
156 | #ifdef CONFIG_CGROUP_WRITEBACK |
157 | ||
ed288dc0 TH |
158 | struct bdi_writeback *wb_get_lookup(struct backing_dev_info *bdi, |
159 | struct cgroup_subsys_state *memcg_css); | |
52ebea74 TH |
160 | struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, |
161 | struct cgroup_subsys_state *memcg_css, | |
162 | gfp_t gfp); | |
52ebea74 TH |
163 | void wb_memcg_offline(struct mem_cgroup *memcg); |
164 | void wb_blkcg_offline(struct blkcg *blkcg); | |
703c2708 | 165 | int inode_congested(struct inode *inode, int cong_bits); |
52ebea74 | 166 | |
89e9b9e0 TH |
167 | /** |
168 | * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode | |
169 | * @inode: inode of interest | |
170 | * | |
ed7b6b4f CH |
171 | * Cgroup writeback requires support from the filesystem. Also, both memcg and |
172 | * iocg have to be on the default hierarchy. Test whether all conditions are | |
173 | * met. | |
9badce00 TH |
174 | * |
175 | * Note that the test result may change dynamically on the same inode | |
176 | * depending on how memcg and iocg are configured. | |
89e9b9e0 TH |
177 | */ |
178 | static inline bool inode_cgwb_enabled(struct inode *inode) | |
179 | { | |
180 | struct backing_dev_info *bdi = inode_to_bdi(inode); | |
181 | ||
c0522908 TH |
182 | return cgroup_subsys_on_dfl(memory_cgrp_subsys) && |
183 | cgroup_subsys_on_dfl(io_cgrp_subsys) && | |
f56753ac | 184 | (bdi->capabilities & BDI_CAP_WRITEBACK) && |
46b15caa | 185 | (inode->i_sb->s_iflags & SB_I_CGROUPWB); |
89e9b9e0 TH |
186 | } |
187 | ||
52ebea74 TH |
188 | /** |
189 | * wb_find_current - find wb for %current on a bdi | |
190 | * @bdi: bdi of interest | |
191 | * | |
192 | * Find the wb of @bdi which matches both the memcg and blkcg of %current. | |
193 | * Must be called under rcu_read_lock() which protects the returend wb. | |
194 | * NULL if not found. | |
195 | */ | |
196 | static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi) | |
197 | { | |
198 | struct cgroup_subsys_state *memcg_css; | |
199 | struct bdi_writeback *wb; | |
200 | ||
201 | memcg_css = task_css(current, memory_cgrp_id); | |
202 | if (!memcg_css->parent) | |
203 | return &bdi->wb; | |
204 | ||
205 | wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); | |
206 | ||
207 | /* | |
208 | * %current's blkcg equals the effective blkcg of its memcg. No | |
209 | * need to use the relatively expensive cgroup_get_e_css(). | |
210 | */ | |
c165b3e3 | 211 | if (likely(wb && wb->blkcg_css == task_css(current, io_cgrp_id))) |
52ebea74 TH |
212 | return wb; |
213 | return NULL; | |
214 | } | |
215 | ||
216 | /** | |
217 | * wb_get_create_current - get or create wb for %current on a bdi | |
218 | * @bdi: bdi of interest | |
219 | * @gfp: allocation mask | |
220 | * | |
221 | * Equivalent to wb_get_create() on %current's memcg. This function is | |
222 | * called from a relatively hot path and optimizes the common cases using | |
223 | * wb_find_current(). | |
224 | */ | |
225 | static inline struct bdi_writeback * | |
226 | wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp) | |
227 | { | |
228 | struct bdi_writeback *wb; | |
229 | ||
230 | rcu_read_lock(); | |
231 | wb = wb_find_current(bdi); | |
232 | if (wb && unlikely(!wb_tryget(wb))) | |
233 | wb = NULL; | |
234 | rcu_read_unlock(); | |
235 | ||
236 | if (unlikely(!wb)) { | |
237 | struct cgroup_subsys_state *memcg_css; | |
238 | ||
239 | memcg_css = task_get_css(current, memory_cgrp_id); | |
240 | wb = wb_get_create(bdi, memcg_css, gfp); | |
241 | css_put(memcg_css); | |
242 | } | |
243 | return wb; | |
244 | } | |
245 | ||
aaa2cacf TH |
246 | /** |
247 | * inode_to_wb_is_valid - test whether an inode has a wb associated | |
248 | * @inode: inode of interest | |
249 | * | |
250 | * Returns %true if @inode has a wb associated. May be called without any | |
251 | * locking. | |
252 | */ | |
253 | static inline bool inode_to_wb_is_valid(struct inode *inode) | |
254 | { | |
255 | return inode->i_wb; | |
256 | } | |
257 | ||
52ebea74 TH |
258 | /** |
259 | * inode_to_wb - determine the wb of an inode | |
260 | * @inode: inode of interest | |
261 | * | |
aaa2cacf | 262 | * Returns the wb @inode is currently associated with. The caller must be |
b93b0163 | 263 | * holding either @inode->i_lock, the i_pages lock, or the |
aaa2cacf | 264 | * associated wb's list_lock. |
52ebea74 | 265 | */ |
05b93801 | 266 | static inline struct bdi_writeback *inode_to_wb(const struct inode *inode) |
52ebea74 | 267 | { |
aaa2cacf TH |
268 | #ifdef CONFIG_LOCKDEP |
269 | WARN_ON_ONCE(debug_locks && | |
270 | (!lockdep_is_held(&inode->i_lock) && | |
b93b0163 | 271 | !lockdep_is_held(&inode->i_mapping->i_pages.xa_lock) && |
aaa2cacf TH |
272 | !lockdep_is_held(&inode->i_wb->list_lock))); |
273 | #endif | |
52ebea74 TH |
274 | return inode->i_wb; |
275 | } | |
276 | ||
fee468fd JK |
277 | static inline struct bdi_writeback *inode_to_wb_wbc( |
278 | struct inode *inode, | |
279 | struct writeback_control *wbc) | |
280 | { | |
281 | /* | |
282 | * If wbc does not have inode attached, it means cgroup writeback was | |
283 | * disabled when wbc started. Just use the default wb in that case. | |
284 | */ | |
285 | return wbc->wb ? wbc->wb : &inode_to_bdi(inode)->wb; | |
286 | } | |
287 | ||
682aa8e1 TH |
288 | /** |
289 | * unlocked_inode_to_wb_begin - begin unlocked inode wb access transaction | |
290 | * @inode: target inode | |
2e898e4c | 291 | * @cookie: output param, to be passed to the end function |
682aa8e1 TH |
292 | * |
293 | * The caller wants to access the wb associated with @inode but isn't | |
b93b0163 | 294 | * holding inode->i_lock, the i_pages lock or wb->list_lock. This |
682aa8e1 TH |
295 | * function determines the wb associated with @inode and ensures that the |
296 | * association doesn't change until the transaction is finished with | |
297 | * unlocked_inode_to_wb_end(). | |
298 | * | |
2e898e4c GT |
299 | * The caller must call unlocked_inode_to_wb_end() with *@cookie afterwards and |
300 | * can't sleep during the transaction. IRQs may or may not be disabled on | |
301 | * return. | |
682aa8e1 TH |
302 | */ |
303 | static inline struct bdi_writeback * | |
2e898e4c | 304 | unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie) |
682aa8e1 TH |
305 | { |
306 | rcu_read_lock(); | |
307 | ||
308 | /* | |
a9519def | 309 | * Paired with store_release in inode_switch_wbs_work_fn() and |
682aa8e1 TH |
310 | * ensures that we see the new wb if we see cleared I_WB_SWITCH. |
311 | */ | |
2e898e4c | 312 | cookie->locked = smp_load_acquire(&inode->i_state) & I_WB_SWITCH; |
682aa8e1 | 313 | |
2e898e4c GT |
314 | if (unlikely(cookie->locked)) |
315 | xa_lock_irqsave(&inode->i_mapping->i_pages, cookie->flags); | |
aaa2cacf TH |
316 | |
317 | /* | |
b93b0163 MW |
318 | * Protected by either !I_WB_SWITCH + rcu_read_lock() or the i_pages |
319 | * lock. inode_to_wb() will bark. Deref directly. | |
aaa2cacf TH |
320 | */ |
321 | return inode->i_wb; | |
682aa8e1 TH |
322 | } |
323 | ||
324 | /** | |
325 | * unlocked_inode_to_wb_end - end inode wb access transaction | |
326 | * @inode: target inode | |
2e898e4c | 327 | * @cookie: @cookie from unlocked_inode_to_wb_begin() |
682aa8e1 | 328 | */ |
2e898e4c GT |
329 | static inline void unlocked_inode_to_wb_end(struct inode *inode, |
330 | struct wb_lock_cookie *cookie) | |
682aa8e1 | 331 | { |
2e898e4c GT |
332 | if (unlikely(cookie->locked)) |
333 | xa_unlock_irqrestore(&inode->i_mapping->i_pages, cookie->flags); | |
682aa8e1 TH |
334 | |
335 | rcu_read_unlock(); | |
336 | } | |
337 | ||
89e9b9e0 TH |
338 | #else /* CONFIG_CGROUP_WRITEBACK */ |
339 | ||
340 | static inline bool inode_cgwb_enabled(struct inode *inode) | |
341 | { | |
342 | return false; | |
343 | } | |
344 | ||
52ebea74 TH |
345 | static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi) |
346 | { | |
347 | return &bdi->wb; | |
348 | } | |
349 | ||
350 | static inline struct bdi_writeback * | |
351 | wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp) | |
352 | { | |
353 | return &bdi->wb; | |
354 | } | |
355 | ||
aaa2cacf TH |
356 | static inline bool inode_to_wb_is_valid(struct inode *inode) |
357 | { | |
358 | return true; | |
359 | } | |
360 | ||
52ebea74 TH |
361 | static inline struct bdi_writeback *inode_to_wb(struct inode *inode) |
362 | { | |
363 | return &inode_to_bdi(inode)->wb; | |
364 | } | |
365 | ||
fee468fd JK |
366 | static inline struct bdi_writeback *inode_to_wb_wbc( |
367 | struct inode *inode, | |
368 | struct writeback_control *wbc) | |
369 | { | |
370 | return inode_to_wb(inode); | |
371 | } | |
372 | ||
373 | ||
682aa8e1 | 374 | static inline struct bdi_writeback * |
2e898e4c | 375 | unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie) |
682aa8e1 TH |
376 | { |
377 | return inode_to_wb(inode); | |
378 | } | |
379 | ||
2e898e4c GT |
380 | static inline void unlocked_inode_to_wb_end(struct inode *inode, |
381 | struct wb_lock_cookie *cookie) | |
682aa8e1 TH |
382 | { |
383 | } | |
384 | ||
52ebea74 TH |
385 | static inline void wb_memcg_offline(struct mem_cgroup *memcg) |
386 | { | |
387 | } | |
388 | ||
389 | static inline void wb_blkcg_offline(struct blkcg *blkcg) | |
390 | { | |
391 | } | |
392 | ||
703c2708 TH |
393 | static inline int inode_congested(struct inode *inode, int cong_bits) |
394 | { | |
395 | return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); | |
396 | } | |
397 | ||
89e9b9e0 TH |
398 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
399 | ||
703c2708 TH |
400 | static inline int inode_read_congested(struct inode *inode) |
401 | { | |
402 | return inode_congested(inode, 1 << WB_sync_congested); | |
403 | } | |
404 | ||
405 | static inline int inode_write_congested(struct inode *inode) | |
406 | { | |
407 | return inode_congested(inode, 1 << WB_async_congested); | |
408 | } | |
409 | ||
410 | static inline int inode_rw_congested(struct inode *inode) | |
411 | { | |
412 | return inode_congested(inode, (1 << WB_sync_congested) | | |
413 | (1 << WB_async_congested)); | |
414 | } | |
415 | ||
ec8a6f26 TH |
416 | static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) |
417 | { | |
418 | return wb_congested(&bdi->wb, cong_bits); | |
419 | } | |
420 | ||
421 | static inline int bdi_read_congested(struct backing_dev_info *bdi) | |
422 | { | |
423 | return bdi_congested(bdi, 1 << WB_sync_congested); | |
424 | } | |
425 | ||
426 | static inline int bdi_write_congested(struct backing_dev_info *bdi) | |
427 | { | |
428 | return bdi_congested(bdi, 1 << WB_async_congested); | |
429 | } | |
430 | ||
431 | static inline int bdi_rw_congested(struct backing_dev_info *bdi) | |
432 | { | |
433 | return bdi_congested(bdi, (1 << WB_sync_congested) | | |
434 | (1 << WB_async_congested)); | |
435 | } | |
436 | ||
eb7ae5e0 | 437 | const char *bdi_dev_name(struct backing_dev_info *bdi); |
68f23b89 | 438 | |
89e9b9e0 | 439 | #endif /* _LINUX_BACKING_DEV_H */ |