Commit | Line | Data |
---|---|---|
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> |
a13f35e8 | 18 | #include <linux/slab.h> |
de1414a6 | 19 | |
8077c0d9 | 20 | int __must_check bdi_init(struct backing_dev_info *bdi); |
b2e8fb6e PZ |
21 | void bdi_destroy(struct backing_dev_info *bdi); |
22 | ||
d2cc4dde | 23 | __printf(3, 4) |
cf0ca9fe PZ |
24 | int bdi_register(struct backing_dev_info *bdi, struct device *parent, |
25 | const char *fmt, ...); | |
26 | int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); | |
b4caecd4 | 27 | int __must_check bdi_setup_and_register(struct backing_dev_info *, char *); |
c00ddad3 TH |
28 | void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, |
29 | bool range_cyclic, enum wb_reason reason); | |
9ecf4866 | 30 | void wb_start_background_writeback(struct bdi_writeback *wb); |
f0054bb1 | 31 | void wb_workfn(struct work_struct *work); |
f0054bb1 | 32 | void wb_wakeup_delayed(struct bdi_writeback *wb); |
cf0ca9fe | 33 | |
03ba3782 | 34 | extern spinlock_t bdi_lock; |
66f3b8e2 JA |
35 | extern struct list_head bdi_list; |
36 | ||
839a8e86 TH |
37 | extern struct workqueue_struct *bdi_wq; |
38 | ||
d6c10f1f | 39 | static inline bool wb_has_dirty_io(struct bdi_writeback *wb) |
03ba3782 | 40 | { |
d6c10f1f | 41 | return test_bit(WB_has_dirty_io, &wb->state); |
03ba3782 JA |
42 | } |
43 | ||
95a46c65 TH |
44 | static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi) |
45 | { | |
46 | /* | |
47 | * @bdi->tot_write_bandwidth is guaranteed to be > 0 if there are | |
48 | * any dirty wbs. See wb_update_write_bandwidth(). | |
49 | */ | |
50 | return atomic_long_read(&bdi->tot_write_bandwidth); | |
03ba3782 JA |
51 | } |
52 | ||
93f78d88 TH |
53 | static inline void __add_wb_stat(struct bdi_writeback *wb, |
54 | enum wb_stat_item item, s64 amount) | |
b2e8fb6e | 55 | { |
93f78d88 | 56 | __percpu_counter_add(&wb->stat[item], amount, WB_STAT_BATCH); |
b2e8fb6e PZ |
57 | } |
58 | ||
93f78d88 TH |
59 | static inline void __inc_wb_stat(struct bdi_writeback *wb, |
60 | enum wb_stat_item item) | |
b2e8fb6e | 61 | { |
93f78d88 | 62 | __add_wb_stat(wb, item, 1); |
b2e8fb6e PZ |
63 | } |
64 | ||
93f78d88 | 65 | static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e PZ |
66 | { |
67 | unsigned long flags; | |
68 | ||
69 | local_irq_save(flags); | |
93f78d88 | 70 | __inc_wb_stat(wb, item); |
b2e8fb6e PZ |
71 | local_irq_restore(flags); |
72 | } | |
73 | ||
93f78d88 TH |
74 | static inline void __dec_wb_stat(struct bdi_writeback *wb, |
75 | enum wb_stat_item item) | |
b2e8fb6e | 76 | { |
93f78d88 | 77 | __add_wb_stat(wb, item, -1); |
b2e8fb6e PZ |
78 | } |
79 | ||
93f78d88 | 80 | static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e PZ |
81 | { |
82 | unsigned long flags; | |
83 | ||
84 | local_irq_save(flags); | |
93f78d88 | 85 | __dec_wb_stat(wb, item); |
b2e8fb6e PZ |
86 | local_irq_restore(flags); |
87 | } | |
88 | ||
93f78d88 | 89 | static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item) |
b2e8fb6e | 90 | { |
93f78d88 | 91 | return percpu_counter_read_positive(&wb->stat[item]); |
b2e8fb6e PZ |
92 | } |
93 | ||
93f78d88 TH |
94 | static inline s64 __wb_stat_sum(struct bdi_writeback *wb, |
95 | enum wb_stat_item item) | |
b2e8fb6e | 96 | { |
93f78d88 | 97 | return percpu_counter_sum_positive(&wb->stat[item]); |
b2e8fb6e PZ |
98 | } |
99 | ||
93f78d88 | 100 | static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item) |
e0bf68dd | 101 | { |
b2e8fb6e PZ |
102 | s64 sum; |
103 | unsigned long flags; | |
104 | ||
105 | local_irq_save(flags); | |
93f78d88 | 106 | sum = __wb_stat_sum(wb, item); |
b2e8fb6e PZ |
107 | local_irq_restore(flags); |
108 | ||
109 | return sum; | |
e0bf68dd PZ |
110 | } |
111 | ||
93f78d88 | 112 | extern void wb_writeout_inc(struct bdi_writeback *wb); |
dd5656e5 | 113 | |
b2e8fb6e PZ |
114 | /* |
115 | * maximal error of a stat counter. | |
116 | */ | |
93f78d88 | 117 | static inline unsigned long wb_stat_error(struct bdi_writeback *wb) |
e0bf68dd | 118 | { |
b2e8fb6e | 119 | #ifdef CONFIG_SMP |
93f78d88 | 120 | return nr_cpu_ids * WB_STAT_BATCH; |
b2e8fb6e PZ |
121 | #else |
122 | return 1; | |
123 | #endif | |
e0bf68dd | 124 | } |
1da177e4 | 125 | |
189d3c4a | 126 | int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio); |
a42dde04 | 127 | int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); |
189d3c4a | 128 | |
1da177e4 LT |
129 | /* |
130 | * Flags in backing_dev_info::capability | |
e4ad08fe MS |
131 | * |
132 | * The first three flags control whether dirty pages will contribute to the | |
133 | * VM's accounting and whether writepages() should be called for dirty pages | |
134 | * (something that would not, for example, be appropriate for ramfs) | |
135 | * | |
136 | * WARNING: these flags are closely related and should not normally be | |
137 | * used separately. The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these | |
138 | * three flags into a single convenience macro. | |
139 | * | |
140 | * BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting | |
141 | * BDI_CAP_NO_WRITEBACK: Don't write pages back | |
142 | * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages | |
5a537485 | 143 | * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. |
89e9b9e0 TH |
144 | * |
145 | * BDI_CAP_CGROUP_WRITEBACK: Supports cgroup-aware writeback. | |
1da177e4 | 146 | */ |
e4ad08fe MS |
147 | #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 |
148 | #define BDI_CAP_NO_WRITEBACK 0x00000002 | |
b4caecd4 CH |
149 | #define BDI_CAP_NO_ACCT_WB 0x00000004 |
150 | #define BDI_CAP_STABLE_WRITES 0x00000008 | |
151 | #define BDI_CAP_STRICTLIMIT 0x00000010 | |
89e9b9e0 | 152 | #define BDI_CAP_CGROUP_WRITEBACK 0x00000020 |
1da177e4 | 153 | |
e4ad08fe MS |
154 | #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ |
155 | (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) | |
156 | ||
5129a469 | 157 | extern struct backing_dev_info noop_backing_dev_info; |
1da177e4 | 158 | |
bc05873d TH |
159 | /** |
160 | * writeback_in_progress - determine whether there is writeback in progress | |
161 | * @wb: bdi_writeback of interest | |
162 | * | |
163 | * Determine whether there is writeback waiting to be handled against a | |
164 | * bdi_writeback. | |
165 | */ | |
166 | static inline bool writeback_in_progress(struct bdi_writeback *wb) | |
1da177e4 | 167 | { |
bc05873d | 168 | return test_bit(WB_writeback_running, &wb->state); |
1da177e4 LT |
169 | } |
170 | ||
a212b105 | 171 | static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) |
1da177e4 | 172 | { |
a212b105 | 173 | struct super_block *sb; |
1da177e4 | 174 | |
a212b105 TH |
175 | if (!inode) |
176 | return &noop_backing_dev_info; | |
177 | ||
178 | sb = inode->i_sb; | |
179 | #ifdef CONFIG_BLOCK | |
180 | if (sb_is_blkdev_sb(sb)) | |
181 | return blk_get_backing_dev_info(I_BDEV(inode)); | |
182 | #endif | |
183 | return sb->s_bdi; | |
1da177e4 LT |
184 | } |
185 | ||
ec8a6f26 | 186 | static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) |
1da177e4 | 187 | { |
ec8a6f26 | 188 | struct backing_dev_info *bdi = wb->bdi; |
1da177e4 | 189 | |
ec8a6f26 TH |
190 | if (bdi->congested_fn) |
191 | return bdi->congested_fn(bdi->congested_data, cong_bits); | |
192 | return wb->congested->state & cong_bits; | |
1da177e4 | 193 | } |
373c0a7e | 194 | |
8aa7e847 | 195 | long congestion_wait(int sync, long timeout); |
0e093d99 | 196 | long wait_iff_congested(struct zone *zone, int sync, long timeout); |
3965c9ae WL |
197 | int pdflush_proc_obsolete(struct ctl_table *table, int write, |
198 | void __user *buffer, size_t *lenp, loff_t *ppos); | |
1da177e4 | 199 | |
7d311cda DW |
200 | static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) |
201 | { | |
202 | return bdi->capabilities & BDI_CAP_STABLE_WRITES; | |
203 | } | |
204 | ||
e4ad08fe MS |
205 | static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) |
206 | { | |
207 | return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); | |
208 | } | |
209 | ||
210 | static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) | |
211 | { | |
212 | return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); | |
213 | } | |
1da177e4 | 214 | |
e4ad08fe MS |
215 | static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi) |
216 | { | |
217 | /* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */ | |
218 | return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB | | |
219 | BDI_CAP_NO_WRITEBACK)); | |
220 | } | |
1da177e4 | 221 | |
e4ad08fe MS |
222 | static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) |
223 | { | |
de1414a6 | 224 | return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host)); |
e4ad08fe | 225 | } |
1da177e4 | 226 | |
e4ad08fe MS |
227 | static inline bool mapping_cap_account_dirty(struct address_space *mapping) |
228 | { | |
de1414a6 | 229 | return bdi_cap_account_dirty(inode_to_bdi(mapping->host)); |
e4ad08fe | 230 | } |
1da177e4 | 231 | |
03ba3782 JA |
232 | static inline int bdi_sched_wait(void *word) |
233 | { | |
234 | schedule(); | |
235 | return 0; | |
236 | } | |
237 | ||
89e9b9e0 TH |
238 | #ifdef CONFIG_CGROUP_WRITEBACK |
239 | ||
52ebea74 TH |
240 | struct bdi_writeback_congested * |
241 | wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp); | |
242 | void wb_congested_put(struct bdi_writeback_congested *congested); | |
243 | struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, | |
244 | struct cgroup_subsys_state *memcg_css, | |
245 | gfp_t gfp); | |
52ebea74 TH |
246 | void wb_memcg_offline(struct mem_cgroup *memcg); |
247 | void wb_blkcg_offline(struct blkcg *blkcg); | |
703c2708 | 248 | int inode_congested(struct inode *inode, int cong_bits); |
52ebea74 | 249 | |
89e9b9e0 TH |
250 | /** |
251 | * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode | |
252 | * @inode: inode of interest | |
253 | * | |
254 | * cgroup writeback requires support from both the bdi and filesystem. | |
255 | * Test whether @inode has both. | |
256 | */ | |
257 | static inline bool inode_cgwb_enabled(struct inode *inode) | |
258 | { | |
259 | struct backing_dev_info *bdi = inode_to_bdi(inode); | |
260 | ||
261 | return bdi_cap_account_dirty(bdi) && | |
262 | (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) && | |
46b15caa | 263 | (inode->i_sb->s_iflags & SB_I_CGROUPWB); |
89e9b9e0 TH |
264 | } |
265 | ||
52ebea74 TH |
266 | /** |
267 | * wb_find_current - find wb for %current on a bdi | |
268 | * @bdi: bdi of interest | |
269 | * | |
270 | * Find the wb of @bdi which matches both the memcg and blkcg of %current. | |
271 | * Must be called under rcu_read_lock() which protects the returend wb. | |
272 | * NULL if not found. | |
273 | */ | |
274 | static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi) | |
275 | { | |
276 | struct cgroup_subsys_state *memcg_css; | |
277 | struct bdi_writeback *wb; | |
278 | ||
279 | memcg_css = task_css(current, memory_cgrp_id); | |
280 | if (!memcg_css->parent) | |
281 | return &bdi->wb; | |
282 | ||
283 | wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); | |
284 | ||
285 | /* | |
286 | * %current's blkcg equals the effective blkcg of its memcg. No | |
287 | * need to use the relatively expensive cgroup_get_e_css(). | |
288 | */ | |
289 | if (likely(wb && wb->blkcg_css == task_css(current, blkio_cgrp_id))) | |
290 | return wb; | |
291 | return NULL; | |
292 | } | |
293 | ||
294 | /** | |
295 | * wb_get_create_current - get or create wb for %current on a bdi | |
296 | * @bdi: bdi of interest | |
297 | * @gfp: allocation mask | |
298 | * | |
299 | * Equivalent to wb_get_create() on %current's memcg. This function is | |
300 | * called from a relatively hot path and optimizes the common cases using | |
301 | * wb_find_current(). | |
302 | */ | |
303 | static inline struct bdi_writeback * | |
304 | wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp) | |
305 | { | |
306 | struct bdi_writeback *wb; | |
307 | ||
308 | rcu_read_lock(); | |
309 | wb = wb_find_current(bdi); | |
310 | if (wb && unlikely(!wb_tryget(wb))) | |
311 | wb = NULL; | |
312 | rcu_read_unlock(); | |
313 | ||
314 | if (unlikely(!wb)) { | |
315 | struct cgroup_subsys_state *memcg_css; | |
316 | ||
317 | memcg_css = task_get_css(current, memory_cgrp_id); | |
318 | wb = wb_get_create(bdi, memcg_css, gfp); | |
319 | css_put(memcg_css); | |
320 | } | |
321 | return wb; | |
322 | } | |
323 | ||
aaa2cacf TH |
324 | /** |
325 | * inode_to_wb_is_valid - test whether an inode has a wb associated | |
326 | * @inode: inode of interest | |
327 | * | |
328 | * Returns %true if @inode has a wb associated. May be called without any | |
329 | * locking. | |
330 | */ | |
331 | static inline bool inode_to_wb_is_valid(struct inode *inode) | |
332 | { | |
333 | return inode->i_wb; | |
334 | } | |
335 | ||
52ebea74 TH |
336 | /** |
337 | * inode_to_wb - determine the wb of an inode | |
338 | * @inode: inode of interest | |
339 | * | |
aaa2cacf TH |
340 | * Returns the wb @inode is currently associated with. The caller must be |
341 | * holding either @inode->i_lock, @inode->i_mapping->tree_lock, or the | |
342 | * associated wb's list_lock. | |
52ebea74 TH |
343 | */ |
344 | static inline struct bdi_writeback *inode_to_wb(struct inode *inode) | |
345 | { | |
aaa2cacf TH |
346 | #ifdef CONFIG_LOCKDEP |
347 | WARN_ON_ONCE(debug_locks && | |
348 | (!lockdep_is_held(&inode->i_lock) && | |
349 | !lockdep_is_held(&inode->i_mapping->tree_lock) && | |
350 | !lockdep_is_held(&inode->i_wb->list_lock))); | |
351 | #endif | |
52ebea74 TH |
352 | return inode->i_wb; |
353 | } | |
354 | ||
682aa8e1 TH |
355 | /** |
356 | * unlocked_inode_to_wb_begin - begin unlocked inode wb access transaction | |
357 | * @inode: target inode | |
358 | * @lockedp: temp bool output param, to be passed to the end function | |
359 | * | |
360 | * The caller wants to access the wb associated with @inode but isn't | |
361 | * holding inode->i_lock, mapping->tree_lock or wb->list_lock. This | |
362 | * function determines the wb associated with @inode and ensures that the | |
363 | * association doesn't change until the transaction is finished with | |
364 | * unlocked_inode_to_wb_end(). | |
365 | * | |
366 | * The caller must call unlocked_inode_to_wb_end() with *@lockdep | |
367 | * afterwards and can't sleep during transaction. IRQ may or may not be | |
368 | * disabled on return. | |
369 | */ | |
370 | static inline struct bdi_writeback * | |
371 | unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp) | |
372 | { | |
373 | rcu_read_lock(); | |
374 | ||
375 | /* | |
376 | * Paired with store_release in inode_switch_wb_work_fn() and | |
377 | * ensures that we see the new wb if we see cleared I_WB_SWITCH. | |
378 | */ | |
379 | *lockedp = smp_load_acquire(&inode->i_state) & I_WB_SWITCH; | |
380 | ||
381 | if (unlikely(*lockedp)) | |
382 | spin_lock_irq(&inode->i_mapping->tree_lock); | |
aaa2cacf TH |
383 | |
384 | /* | |
385 | * Protected by either !I_WB_SWITCH + rcu_read_lock() or tree_lock. | |
386 | * inode_to_wb() will bark. Deref directly. | |
387 | */ | |
388 | return inode->i_wb; | |
682aa8e1 TH |
389 | } |
390 | ||
391 | /** | |
392 | * unlocked_inode_to_wb_end - end inode wb access transaction | |
393 | * @inode: target inode | |
394 | * @locked: *@lockedp from unlocked_inode_to_wb_begin() | |
395 | */ | |
396 | static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked) | |
397 | { | |
398 | if (unlikely(locked)) | |
399 | spin_unlock_irq(&inode->i_mapping->tree_lock); | |
400 | ||
401 | rcu_read_unlock(); | |
402 | } | |
403 | ||
ebe41ab0 TH |
404 | struct wb_iter { |
405 | int start_blkcg_id; | |
406 | struct radix_tree_iter tree_iter; | |
407 | void **slot; | |
408 | }; | |
409 | ||
410 | static inline struct bdi_writeback *__wb_iter_next(struct wb_iter *iter, | |
411 | struct backing_dev_info *bdi) | |
412 | { | |
413 | struct radix_tree_iter *titer = &iter->tree_iter; | |
414 | ||
415 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
416 | ||
417 | if (iter->start_blkcg_id >= 0) { | |
418 | iter->slot = radix_tree_iter_init(titer, iter->start_blkcg_id); | |
419 | iter->start_blkcg_id = -1; | |
420 | } else { | |
421 | iter->slot = radix_tree_next_slot(iter->slot, titer, 0); | |
422 | } | |
423 | ||
424 | if (!iter->slot) | |
425 | iter->slot = radix_tree_next_chunk(&bdi->cgwb_tree, titer, 0); | |
426 | if (iter->slot) | |
427 | return *iter->slot; | |
428 | return NULL; | |
429 | } | |
430 | ||
431 | static inline struct bdi_writeback *__wb_iter_init(struct wb_iter *iter, | |
432 | struct backing_dev_info *bdi, | |
433 | int start_blkcg_id) | |
434 | { | |
435 | iter->start_blkcg_id = start_blkcg_id; | |
436 | ||
437 | if (start_blkcg_id) | |
438 | return __wb_iter_next(iter, bdi); | |
439 | else | |
440 | return &bdi->wb; | |
441 | } | |
442 | ||
443 | /** | |
444 | * bdi_for_each_wb - walk all wb's of a bdi in ascending blkcg ID order | |
445 | * @wb_cur: cursor struct bdi_writeback pointer | |
446 | * @bdi: bdi to walk wb's of | |
447 | * @iter: pointer to struct wb_iter to be used as iteration buffer | |
448 | * @start_blkcg_id: blkcg ID to start iteration from | |
449 | * | |
450 | * Iterate @wb_cur through the wb's (bdi_writeback's) of @bdi in ascending | |
451 | * blkcg ID order starting from @start_blkcg_id. @iter is struct wb_iter | |
452 | * to be used as temp storage during iteration. rcu_read_lock() must be | |
453 | * held throughout iteration. | |
454 | */ | |
455 | #define bdi_for_each_wb(wb_cur, bdi, iter, start_blkcg_id) \ | |
456 | for ((wb_cur) = __wb_iter_init(iter, bdi, start_blkcg_id); \ | |
457 | (wb_cur); (wb_cur) = __wb_iter_next(iter, bdi)) | |
458 | ||
89e9b9e0 TH |
459 | #else /* CONFIG_CGROUP_WRITEBACK */ |
460 | ||
461 | static inline bool inode_cgwb_enabled(struct inode *inode) | |
462 | { | |
463 | return false; | |
464 | } | |
465 | ||
52ebea74 TH |
466 | static inline struct bdi_writeback_congested * |
467 | wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp) | |
468 | { | |
a13f35e8 TH |
469 | atomic_inc(&bdi->wb_congested->refcnt); |
470 | return bdi->wb_congested; | |
52ebea74 TH |
471 | } |
472 | ||
473 | static inline void wb_congested_put(struct bdi_writeback_congested *congested) | |
474 | { | |
a13f35e8 TH |
475 | if (atomic_dec_and_test(&congested->refcnt)) |
476 | kfree(congested); | |
52ebea74 TH |
477 | } |
478 | ||
52ebea74 TH |
479 | static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi) |
480 | { | |
481 | return &bdi->wb; | |
482 | } | |
483 | ||
484 | static inline struct bdi_writeback * | |
485 | wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp) | |
486 | { | |
487 | return &bdi->wb; | |
488 | } | |
489 | ||
aaa2cacf TH |
490 | static inline bool inode_to_wb_is_valid(struct inode *inode) |
491 | { | |
492 | return true; | |
493 | } | |
494 | ||
52ebea74 TH |
495 | static inline struct bdi_writeback *inode_to_wb(struct inode *inode) |
496 | { | |
497 | return &inode_to_bdi(inode)->wb; | |
498 | } | |
499 | ||
682aa8e1 TH |
500 | static inline struct bdi_writeback * |
501 | unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp) | |
502 | { | |
503 | return inode_to_wb(inode); | |
504 | } | |
505 | ||
506 | static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked) | |
507 | { | |
508 | } | |
509 | ||
52ebea74 TH |
510 | static inline void wb_memcg_offline(struct mem_cgroup *memcg) |
511 | { | |
512 | } | |
513 | ||
514 | static inline void wb_blkcg_offline(struct blkcg *blkcg) | |
515 | { | |
516 | } | |
517 | ||
ebe41ab0 TH |
518 | struct wb_iter { |
519 | int next_id; | |
520 | }; | |
521 | ||
522 | #define bdi_for_each_wb(wb_cur, bdi, iter, start_blkcg_id) \ | |
523 | for ((iter)->next_id = (start_blkcg_id); \ | |
524 | ({ (wb_cur) = !(iter)->next_id++ ? &(bdi)->wb : NULL; }); ) | |
525 | ||
703c2708 TH |
526 | static inline int inode_congested(struct inode *inode, int cong_bits) |
527 | { | |
528 | return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); | |
529 | } | |
530 | ||
89e9b9e0 TH |
531 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
532 | ||
703c2708 TH |
533 | static inline int inode_read_congested(struct inode *inode) |
534 | { | |
535 | return inode_congested(inode, 1 << WB_sync_congested); | |
536 | } | |
537 | ||
538 | static inline int inode_write_congested(struct inode *inode) | |
539 | { | |
540 | return inode_congested(inode, 1 << WB_async_congested); | |
541 | } | |
542 | ||
543 | static inline int inode_rw_congested(struct inode *inode) | |
544 | { | |
545 | return inode_congested(inode, (1 << WB_sync_congested) | | |
546 | (1 << WB_async_congested)); | |
547 | } | |
548 | ||
ec8a6f26 TH |
549 | static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) |
550 | { | |
551 | return wb_congested(&bdi->wb, cong_bits); | |
552 | } | |
553 | ||
554 | static inline int bdi_read_congested(struct backing_dev_info *bdi) | |
555 | { | |
556 | return bdi_congested(bdi, 1 << WB_sync_congested); | |
557 | } | |
558 | ||
559 | static inline int bdi_write_congested(struct backing_dev_info *bdi) | |
560 | { | |
561 | return bdi_congested(bdi, 1 << WB_async_congested); | |
562 | } | |
563 | ||
564 | static inline int bdi_rw_congested(struct backing_dev_info *bdi) | |
565 | { | |
566 | return bdi_congested(bdi, (1 << WB_sync_congested) | | |
567 | (1 << WB_async_congested)); | |
568 | } | |
569 | ||
89e9b9e0 | 570 | #endif /* _LINUX_BACKING_DEV_H */ |