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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * include/linux/backing-dev.h | |
3 | * | |
4 | * low-level device information and state which is propagated up through | |
5 | * to high-level code. | |
6 | */ | |
7 | ||
8 | #ifndef _LINUX_BACKING_DEV_H | |
9 | #define _LINUX_BACKING_DEV_H | |
10 | ||
cf0ca9fe | 11 | #include <linux/kernel.h> |
e4ad08fe | 12 | #include <linux/fs.h> |
03ba3782 | 13 | #include <linux/sched.h> |
a212b105 | 14 | #include <linux/blkdev.h> |
03ba3782 | 15 | #include <linux/writeback.h> |
52ebea74 | 16 | #include <linux/blk-cgroup.h> |
66114cad | 17 | #include <linux/backing-dev-defs.h> |
de1414a6 | 18 | |
8077c0d9 | 19 | int __must_check bdi_init(struct backing_dev_info *bdi); |
b2e8fb6e PZ |
20 | void bdi_destroy(struct backing_dev_info *bdi); |
21 | ||
d2cc4dde | 22 | __printf(3, 4) |
cf0ca9fe PZ |
23 | int bdi_register(struct backing_dev_info *bdi, struct device *parent, |
24 | const char *fmt, ...); | |
25 | int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); | |
b4caecd4 | 26 | int __must_check bdi_setup_and_register(struct backing_dev_info *, char *); |
c00ddad3 TH |
27 | void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, |
28 | bool range_cyclic, enum wb_reason reason); | |
9ecf4866 | 29 | void wb_start_background_writeback(struct bdi_writeback *wb); |
f0054bb1 | 30 | void wb_workfn(struct work_struct *work); |
f0054bb1 | 31 | void wb_wakeup_delayed(struct bdi_writeback *wb); |
cf0ca9fe | 32 | |
03ba3782 | 33 | extern spinlock_t bdi_lock; |
66f3b8e2 JA |
34 | extern struct list_head bdi_list; |
35 | ||
839a8e86 TH |
36 | extern struct workqueue_struct *bdi_wq; |
37 | ||
d6c10f1f | 38 | static inline bool wb_has_dirty_io(struct bdi_writeback *wb) |
03ba3782 | 39 | { |
d6c10f1f | 40 | return test_bit(WB_has_dirty_io, &wb->state); |
03ba3782 JA |
41 | } |
42 | ||
95a46c65 TH |
43 | static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi) |
44 | { | |
45 | /* | |
46 | * @bdi->tot_write_bandwidth is guaranteed to be > 0 if there are | |
47 | * any dirty wbs. See wb_update_write_bandwidth(). | |
48 | */ | |
49 | return atomic_long_read(&bdi->tot_write_bandwidth); | |
03ba3782 JA |
50 | } |
51 | ||
93f78d88 TH |
52 | static inline void __add_wb_stat(struct bdi_writeback *wb, |
53 | enum wb_stat_item item, s64 amount) | |
b2e8fb6e | 54 | { |
93f78d88 | 55 | __percpu_counter_add(&wb->stat[item], amount, WB_STAT_BATCH); |
b2e8fb6e PZ |
56 | } |
57 | ||
93f78d88 TH |
58 | static inline void __inc_wb_stat(struct bdi_writeback *wb, |
59 | enum wb_stat_item item) | |
b2e8fb6e | 60 | { |
93f78d88 | 61 | __add_wb_stat(wb, item, 1); |
b2e8fb6e PZ |
62 | } |
63 | ||
93f78d88 | 64 | static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e PZ |
65 | { |
66 | unsigned long flags; | |
67 | ||
68 | local_irq_save(flags); | |
93f78d88 | 69 | __inc_wb_stat(wb, item); |
b2e8fb6e PZ |
70 | local_irq_restore(flags); |
71 | } | |
72 | ||
93f78d88 TH |
73 | static inline void __dec_wb_stat(struct bdi_writeback *wb, |
74 | enum wb_stat_item item) | |
b2e8fb6e | 75 | { |
93f78d88 | 76 | __add_wb_stat(wb, item, -1); |
b2e8fb6e PZ |
77 | } |
78 | ||
93f78d88 | 79 | static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e PZ |
80 | { |
81 | unsigned long flags; | |
82 | ||
83 | local_irq_save(flags); | |
93f78d88 | 84 | __dec_wb_stat(wb, item); |
b2e8fb6e PZ |
85 | local_irq_restore(flags); |
86 | } | |
87 | ||
93f78d88 | 88 | static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e | 89 | { |
93f78d88 | 90 | return percpu_counter_read_positive(&wb->stat[item]); |
b2e8fb6e PZ |
91 | } |
92 | ||
93f78d88 TH |
93 | static inline s64 __wb_stat_sum(struct bdi_writeback *wb, |
94 | enum wb_stat_item item) | |
b2e8fb6e | 95 | { |
93f78d88 | 96 | return percpu_counter_sum_positive(&wb->stat[item]); |
b2e8fb6e PZ |
97 | } |
98 | ||
93f78d88 | 99 | static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item) |
e0bf68dd | 100 | { |
b2e8fb6e PZ |
101 | s64 sum; |
102 | unsigned long flags; | |
103 | ||
104 | local_irq_save(flags); | |
93f78d88 | 105 | sum = __wb_stat_sum(wb, item); |
b2e8fb6e PZ |
106 | local_irq_restore(flags); |
107 | ||
108 | return sum; | |
e0bf68dd PZ |
109 | } |
110 | ||
93f78d88 | 111 | extern void wb_writeout_inc(struct bdi_writeback *wb); |
dd5656e5 | 112 | |
b2e8fb6e PZ |
113 | /* |
114 | * maximal error of a stat counter. | |
115 | */ | |
93f78d88 | 116 | static inline unsigned long wb_stat_error(struct bdi_writeback *wb) |
e0bf68dd | 117 | { |
b2e8fb6e | 118 | #ifdef CONFIG_SMP |
93f78d88 | 119 | return nr_cpu_ids * WB_STAT_BATCH; |
b2e8fb6e PZ |
120 | #else |
121 | return 1; | |
122 | #endif | |
e0bf68dd | 123 | } |
1da177e4 | 124 | |
189d3c4a | 125 | int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio); |
a42dde04 | 126 | int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); |
189d3c4a | 127 | |
1da177e4 LT |
128 | /* |
129 | * Flags in backing_dev_info::capability | |
e4ad08fe MS |
130 | * |
131 | * The first three flags control whether dirty pages will contribute to the | |
132 | * VM's accounting and whether writepages() should be called for dirty pages | |
133 | * (something that would not, for example, be appropriate for ramfs) | |
134 | * | |
135 | * WARNING: these flags are closely related and should not normally be | |
136 | * used separately. The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these | |
137 | * three flags into a single convenience macro. | |
138 | * | |
139 | * BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting | |
140 | * BDI_CAP_NO_WRITEBACK: Don't write pages back | |
141 | * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages | |
5a537485 | 142 | * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. |
89e9b9e0 TH |
143 | * |
144 | * BDI_CAP_CGROUP_WRITEBACK: Supports cgroup-aware writeback. | |
1da177e4 | 145 | */ |
e4ad08fe MS |
146 | #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 |
147 | #define BDI_CAP_NO_WRITEBACK 0x00000002 | |
b4caecd4 CH |
148 | #define BDI_CAP_NO_ACCT_WB 0x00000004 |
149 | #define BDI_CAP_STABLE_WRITES 0x00000008 | |
150 | #define BDI_CAP_STRICTLIMIT 0x00000010 | |
89e9b9e0 | 151 | #define BDI_CAP_CGROUP_WRITEBACK 0x00000020 |
1da177e4 | 152 | |
e4ad08fe MS |
153 | #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ |
154 | (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) | |
155 | ||
5129a469 | 156 | extern struct backing_dev_info noop_backing_dev_info; |
1da177e4 | 157 | |
bc05873d TH |
158 | /** |
159 | * writeback_in_progress - determine whether there is writeback in progress | |
160 | * @wb: bdi_writeback of interest | |
161 | * | |
162 | * Determine whether there is writeback waiting to be handled against a | |
163 | * bdi_writeback. | |
164 | */ | |
165 | static inline bool writeback_in_progress(struct bdi_writeback *wb) | |
1da177e4 | 166 | { |
bc05873d | 167 | return test_bit(WB_writeback_running, &wb->state); |
1da177e4 LT |
168 | } |
169 | ||
a212b105 | 170 | static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) |
1da177e4 | 171 | { |
a212b105 | 172 | struct super_block *sb; |
1da177e4 | 173 | |
a212b105 TH |
174 | if (!inode) |
175 | return &noop_backing_dev_info; | |
176 | ||
177 | sb = inode->i_sb; | |
178 | #ifdef CONFIG_BLOCK | |
179 | if (sb_is_blkdev_sb(sb)) | |
180 | return blk_get_backing_dev_info(I_BDEV(inode)); | |
181 | #endif | |
182 | return sb->s_bdi; | |
1da177e4 LT |
183 | } |
184 | ||
ec8a6f26 | 185 | static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) |
1da177e4 | 186 | { |
ec8a6f26 | 187 | struct backing_dev_info *bdi = wb->bdi; |
1da177e4 | 188 | |
ec8a6f26 TH |
189 | if (bdi->congested_fn) |
190 | return bdi->congested_fn(bdi->congested_data, cong_bits); | |
191 | return wb->congested->state & cong_bits; | |
1da177e4 | 192 | } |
373c0a7e | 193 | |
8aa7e847 | 194 | long congestion_wait(int sync, long timeout); |
0e093d99 | 195 | long wait_iff_congested(struct zone *zone, int sync, long timeout); |
3965c9ae WL |
196 | int pdflush_proc_obsolete(struct ctl_table *table, int write, |
197 | void __user *buffer, size_t *lenp, loff_t *ppos); | |
1da177e4 | 198 | |
7d311cda DW |
199 | static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) |
200 | { | |
201 | return bdi->capabilities & BDI_CAP_STABLE_WRITES; | |
202 | } | |
203 | ||
e4ad08fe MS |
204 | static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) |
205 | { | |
206 | return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); | |
207 | } | |
208 | ||
209 | static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) | |
210 | { | |
211 | return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); | |
212 | } | |
1da177e4 | 213 | |
e4ad08fe MS |
214 | static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi) |
215 | { | |
216 | /* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */ | |
217 | return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB | | |
218 | BDI_CAP_NO_WRITEBACK)); | |
219 | } | |
1da177e4 | 220 | |
e4ad08fe MS |
221 | static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) |
222 | { | |
de1414a6 | 223 | return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host)); |
e4ad08fe | 224 | } |
1da177e4 | 225 | |
e4ad08fe MS |
226 | static inline bool mapping_cap_account_dirty(struct address_space *mapping) |
227 | { | |
de1414a6 | 228 | return bdi_cap_account_dirty(inode_to_bdi(mapping->host)); |
e4ad08fe | 229 | } |
1da177e4 | 230 | |
03ba3782 JA |
231 | static inline int bdi_sched_wait(void *word) |
232 | { | |
233 | schedule(); | |
234 | return 0; | |
235 | } | |
236 | ||
89e9b9e0 TH |
237 | #ifdef CONFIG_CGROUP_WRITEBACK |
238 | ||
52ebea74 TH |
239 | struct bdi_writeback_congested * |
240 | wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp); | |
241 | void wb_congested_put(struct bdi_writeback_congested *congested); | |
242 | struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, | |
243 | struct cgroup_subsys_state *memcg_css, | |
244 | gfp_t gfp); | |
52ebea74 TH |
245 | void wb_memcg_offline(struct mem_cgroup *memcg); |
246 | void wb_blkcg_offline(struct blkcg *blkcg); | |
703c2708 | 247 | int inode_congested(struct inode *inode, int cong_bits); |
52ebea74 | 248 | |
89e9b9e0 TH |
249 | /** |
250 | * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode | |
251 | * @inode: inode of interest | |
252 | * | |
253 | * cgroup writeback requires support from both the bdi and filesystem. | |
254 | * Test whether @inode has both. | |
255 | */ | |
256 | static inline bool inode_cgwb_enabled(struct inode *inode) | |
257 | { | |
258 | struct backing_dev_info *bdi = inode_to_bdi(inode); | |
259 | ||
260 | return bdi_cap_account_dirty(bdi) && | |
261 | (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) && | |
46b15caa | 262 | (inode->i_sb->s_iflags & SB_I_CGROUPWB); |
89e9b9e0 TH |
263 | } |
264 | ||
52ebea74 TH |
265 | /** |
266 | * wb_find_current - find wb for %current on a bdi | |
267 | * @bdi: bdi of interest | |
268 | * | |
269 | * Find the wb of @bdi which matches both the memcg and blkcg of %current. | |
270 | * Must be called under rcu_read_lock() which protects the returend wb. | |
271 | * NULL if not found. | |
272 | */ | |
273 | static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi) | |
274 | { | |
275 | struct cgroup_subsys_state *memcg_css; | |
276 | struct bdi_writeback *wb; | |
277 | ||
278 | memcg_css = task_css(current, memory_cgrp_id); | |
279 | if (!memcg_css->parent) | |
280 | return &bdi->wb; | |
281 | ||
282 | wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); | |
283 | ||
284 | /* | |
285 | * %current's blkcg equals the effective blkcg of its memcg. No | |
286 | * need to use the relatively expensive cgroup_get_e_css(). | |
287 | */ | |
288 | if (likely(wb && wb->blkcg_css == task_css(current, blkio_cgrp_id))) | |
289 | return wb; | |
290 | return NULL; | |
291 | } | |
292 | ||
293 | /** | |
294 | * wb_get_create_current - get or create wb for %current on a bdi | |
295 | * @bdi: bdi of interest | |
296 | * @gfp: allocation mask | |
297 | * | |
298 | * Equivalent to wb_get_create() on %current's memcg. This function is | |
299 | * called from a relatively hot path and optimizes the common cases using | |
300 | * wb_find_current(). | |
301 | */ | |
302 | static inline struct bdi_writeback * | |
303 | wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp) | |
304 | { | |
305 | struct bdi_writeback *wb; | |
306 | ||
307 | rcu_read_lock(); | |
308 | wb = wb_find_current(bdi); | |
309 | if (wb && unlikely(!wb_tryget(wb))) | |
310 | wb = NULL; | |
311 | rcu_read_unlock(); | |
312 | ||
313 | if (unlikely(!wb)) { | |
314 | struct cgroup_subsys_state *memcg_css; | |
315 | ||
316 | memcg_css = task_get_css(current, memory_cgrp_id); | |
317 | wb = wb_get_create(bdi, memcg_css, gfp); | |
318 | css_put(memcg_css); | |
319 | } | |
320 | return wb; | |
321 | } | |
322 | ||
aaa2cacf TH |
323 | /** |
324 | * inode_to_wb_is_valid - test whether an inode has a wb associated | |
325 | * @inode: inode of interest | |
326 | * | |
327 | * Returns %true if @inode has a wb associated. May be called without any | |
328 | * locking. | |
329 | */ | |
330 | static inline bool inode_to_wb_is_valid(struct inode *inode) | |
331 | { | |
332 | return inode->i_wb; | |
333 | } | |
334 | ||
52ebea74 TH |
335 | /** |
336 | * inode_to_wb - determine the wb of an inode | |
337 | * @inode: inode of interest | |
338 | * | |
aaa2cacf TH |
339 | * Returns the wb @inode is currently associated with. The caller must be |
340 | * holding either @inode->i_lock, @inode->i_mapping->tree_lock, or the | |
341 | * associated wb's list_lock. | |
52ebea74 TH |
342 | */ |
343 | static inline struct bdi_writeback *inode_to_wb(struct inode *inode) | |
344 | { | |
aaa2cacf TH |
345 | #ifdef CONFIG_LOCKDEP |
346 | WARN_ON_ONCE(debug_locks && | |
347 | (!lockdep_is_held(&inode->i_lock) && | |
348 | !lockdep_is_held(&inode->i_mapping->tree_lock) && | |
349 | !lockdep_is_held(&inode->i_wb->list_lock))); | |
350 | #endif | |
52ebea74 TH |
351 | return inode->i_wb; |
352 | } | |
353 | ||
682aa8e1 TH |
354 | /** |
355 | * unlocked_inode_to_wb_begin - begin unlocked inode wb access transaction | |
356 | * @inode: target inode | |
357 | * @lockedp: temp bool output param, to be passed to the end function | |
358 | * | |
359 | * The caller wants to access the wb associated with @inode but isn't | |
360 | * holding inode->i_lock, mapping->tree_lock or wb->list_lock. This | |
361 | * function determines the wb associated with @inode and ensures that the | |
362 | * association doesn't change until the transaction is finished with | |
363 | * unlocked_inode_to_wb_end(). | |
364 | * | |
365 | * The caller must call unlocked_inode_to_wb_end() with *@lockdep | |
366 | * afterwards and can't sleep during transaction. IRQ may or may not be | |
367 | * disabled on return. | |
368 | */ | |
369 | static inline struct bdi_writeback * | |
370 | unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp) | |
371 | { | |
372 | rcu_read_lock(); | |
373 | ||
374 | /* | |
375 | * Paired with store_release in inode_switch_wb_work_fn() and | |
376 | * ensures that we see the new wb if we see cleared I_WB_SWITCH. | |
377 | */ | |
378 | *lockedp = smp_load_acquire(&inode->i_state) & I_WB_SWITCH; | |
379 | ||
380 | if (unlikely(*lockedp)) | |
381 | spin_lock_irq(&inode->i_mapping->tree_lock); | |
aaa2cacf TH |
382 | |
383 | /* | |
384 | * Protected by either !I_WB_SWITCH + rcu_read_lock() or tree_lock. | |
385 | * inode_to_wb() will bark. Deref directly. | |
386 | */ | |
387 | return inode->i_wb; | |
682aa8e1 TH |
388 | } |
389 | ||
390 | /** | |
391 | * unlocked_inode_to_wb_end - end inode wb access transaction | |
392 | * @inode: target inode | |
393 | * @locked: *@lockedp from unlocked_inode_to_wb_begin() | |
394 | */ | |
395 | static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked) | |
396 | { | |
397 | if (unlikely(locked)) | |
398 | spin_unlock_irq(&inode->i_mapping->tree_lock); | |
399 | ||
400 | rcu_read_unlock(); | |
401 | } | |
402 | ||
ebe41ab0 TH |
403 | struct wb_iter { |
404 | int start_blkcg_id; | |
405 | struct radix_tree_iter tree_iter; | |
406 | void **slot; | |
407 | }; | |
408 | ||
409 | static inline struct bdi_writeback *__wb_iter_next(struct wb_iter *iter, | |
410 | struct backing_dev_info *bdi) | |
411 | { | |
412 | struct radix_tree_iter *titer = &iter->tree_iter; | |
413 | ||
414 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
415 | ||
416 | if (iter->start_blkcg_id >= 0) { | |
417 | iter->slot = radix_tree_iter_init(titer, iter->start_blkcg_id); | |
418 | iter->start_blkcg_id = -1; | |
419 | } else { | |
420 | iter->slot = radix_tree_next_slot(iter->slot, titer, 0); | |
421 | } | |
422 | ||
423 | if (!iter->slot) | |
424 | iter->slot = radix_tree_next_chunk(&bdi->cgwb_tree, titer, 0); | |
425 | if (iter->slot) | |
426 | return *iter->slot; | |
427 | return NULL; | |
428 | } | |
429 | ||
430 | static inline struct bdi_writeback *__wb_iter_init(struct wb_iter *iter, | |
431 | struct backing_dev_info *bdi, | |
432 | int start_blkcg_id) | |
433 | { | |
434 | iter->start_blkcg_id = start_blkcg_id; | |
435 | ||
436 | if (start_blkcg_id) | |
437 | return __wb_iter_next(iter, bdi); | |
438 | else | |
439 | return &bdi->wb; | |
440 | } | |
441 | ||
442 | /** | |
443 | * bdi_for_each_wb - walk all wb's of a bdi in ascending blkcg ID order | |
444 | * @wb_cur: cursor struct bdi_writeback pointer | |
445 | * @bdi: bdi to walk wb's of | |
446 | * @iter: pointer to struct wb_iter to be used as iteration buffer | |
447 | * @start_blkcg_id: blkcg ID to start iteration from | |
448 | * | |
449 | * Iterate @wb_cur through the wb's (bdi_writeback's) of @bdi in ascending | |
450 | * blkcg ID order starting from @start_blkcg_id. @iter is struct wb_iter | |
451 | * to be used as temp storage during iteration. rcu_read_lock() must be | |
452 | * held throughout iteration. | |
453 | */ | |
454 | #define bdi_for_each_wb(wb_cur, bdi, iter, start_blkcg_id) \ | |
455 | for ((wb_cur) = __wb_iter_init(iter, bdi, start_blkcg_id); \ | |
456 | (wb_cur); (wb_cur) = __wb_iter_next(iter, bdi)) | |
457 | ||
89e9b9e0 TH |
458 | #else /* CONFIG_CGROUP_WRITEBACK */ |
459 | ||
460 | static inline bool inode_cgwb_enabled(struct inode *inode) | |
461 | { | |
462 | return false; | |
463 | } | |
464 | ||
52ebea74 TH |
465 | static inline struct bdi_writeback_congested * |
466 | wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp) | |
467 | { | |
468 | return bdi->wb.congested; | |
469 | } | |
470 | ||
471 | static inline void wb_congested_put(struct bdi_writeback_congested *congested) | |
472 | { | |
473 | } | |
474 | ||
52ebea74 TH |
475 | static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi) |
476 | { | |
477 | return &bdi->wb; | |
478 | } | |
479 | ||
480 | static inline struct bdi_writeback * | |
481 | wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp) | |
482 | { | |
483 | return &bdi->wb; | |
484 | } | |
485 | ||
aaa2cacf TH |
486 | static inline bool inode_to_wb_is_valid(struct inode *inode) |
487 | { | |
488 | return true; | |
489 | } | |
490 | ||
52ebea74 TH |
491 | static inline struct bdi_writeback *inode_to_wb(struct inode *inode) |
492 | { | |
493 | return &inode_to_bdi(inode)->wb; | |
494 | } | |
495 | ||
682aa8e1 TH |
496 | static inline struct bdi_writeback * |
497 | unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp) | |
498 | { | |
499 | return inode_to_wb(inode); | |
500 | } | |
501 | ||
502 | static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked) | |
503 | { | |
504 | } | |
505 | ||
52ebea74 TH |
506 | static inline void wb_memcg_offline(struct mem_cgroup *memcg) |
507 | { | |
508 | } | |
509 | ||
510 | static inline void wb_blkcg_offline(struct blkcg *blkcg) | |
511 | { | |
512 | } | |
513 | ||
ebe41ab0 TH |
514 | struct wb_iter { |
515 | int next_id; | |
516 | }; | |
517 | ||
518 | #define bdi_for_each_wb(wb_cur, bdi, iter, start_blkcg_id) \ | |
519 | for ((iter)->next_id = (start_blkcg_id); \ | |
520 | ({ (wb_cur) = !(iter)->next_id++ ? &(bdi)->wb : NULL; }); ) | |
521 | ||
703c2708 TH |
522 | static inline int inode_congested(struct inode *inode, int cong_bits) |
523 | { | |
524 | return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); | |
525 | } | |
526 | ||
89e9b9e0 TH |
527 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
528 | ||
703c2708 TH |
529 | static inline int inode_read_congested(struct inode *inode) |
530 | { | |
531 | return inode_congested(inode, 1 << WB_sync_congested); | |
532 | } | |
533 | ||
534 | static inline int inode_write_congested(struct inode *inode) | |
535 | { | |
536 | return inode_congested(inode, 1 << WB_async_congested); | |
537 | } | |
538 | ||
539 | static inline int inode_rw_congested(struct inode *inode) | |
540 | { | |
541 | return inode_congested(inode, (1 << WB_sync_congested) | | |
542 | (1 << WB_async_congested)); | |
543 | } | |
544 | ||
ec8a6f26 TH |
545 | static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) |
546 | { | |
547 | return wb_congested(&bdi->wb, cong_bits); | |
548 | } | |
549 | ||
550 | static inline int bdi_read_congested(struct backing_dev_info *bdi) | |
551 | { | |
552 | return bdi_congested(bdi, 1 << WB_sync_congested); | |
553 | } | |
554 | ||
555 | static inline int bdi_write_congested(struct backing_dev_info *bdi) | |
556 | { | |
557 | return bdi_congested(bdi, 1 << WB_async_congested); | |
558 | } | |
559 | ||
560 | static inline int bdi_rw_congested(struct backing_dev_info *bdi) | |
561 | { | |
562 | return bdi_congested(bdi, (1 << WB_sync_congested) | | |
563 | (1 << WB_async_congested)); | |
564 | } | |
565 | ||
89e9b9e0 | 566 | #endif /* _LINUX_BACKING_DEV_H */ |