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9#ifndef _LINUX_BACKING_DEV_H
10#define _LINUX_BACKING_DEV_H
11
12#include <linux/kernel.h>
13#include <linux/fs.h>
14#include <linux/sched.h>
15#include <linux/blkdev.h>
16#include <linux/device.h>
17#include <linux/writeback.h>
18#include <linux/blk-cgroup.h>
19#include <linux/backing-dev-defs.h>
20#include <linux/slab.h>
21
22static inline struct backing_dev_info *bdi_get(struct backing_dev_info *bdi)
23{
24 kref_get(&bdi->refcnt);
25 return bdi;
26}
27
28struct backing_dev_info *bdi_get_by_id(u64 id);
29void bdi_put(struct backing_dev_info *bdi);
30
31__printf(2, 3)
32int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...);
33__printf(2, 0)
34int bdi_register_va(struct backing_dev_info *bdi, const char *fmt,
35 va_list args);
36int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner);
37void bdi_unregister(struct backing_dev_info *bdi);
38
39struct backing_dev_info *bdi_alloc_node(gfp_t gfp_mask, int node_id);
40static inline struct backing_dev_info *bdi_alloc(gfp_t gfp_mask)
41{
42 return bdi_alloc_node(gfp_mask, NUMA_NO_NODE);
43}
44
45void wb_start_background_writeback(struct bdi_writeback *wb);
46void wb_workfn(struct work_struct *work);
47void wb_wakeup_delayed(struct bdi_writeback *wb);
48
49void wb_wait_for_completion(struct wb_completion *done);
50
51extern spinlock_t bdi_lock;
52extern struct list_head bdi_list;
53
54extern struct workqueue_struct *bdi_wq;
55extern struct workqueue_struct *bdi_async_bio_wq;
56
57static inline bool wb_has_dirty_io(struct bdi_writeback *wb)
58{
59 return test_bit(WB_has_dirty_io, &wb->state);
60}
61
62static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi)
63{
64
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67
68 return atomic_long_read(&bdi->tot_write_bandwidth);
69}
70
71static inline void __add_wb_stat(struct bdi_writeback *wb,
72 enum wb_stat_item item, s64 amount)
73{
74 percpu_counter_add_batch(&wb->stat[item], amount, WB_STAT_BATCH);
75}
76
77static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
78{
79 __add_wb_stat(wb, item, 1);
80}
81
82static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
83{
84 __add_wb_stat(wb, item, -1);
85}
86
87static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
88{
89 return percpu_counter_read_positive(&wb->stat[item]);
90}
91
92static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item)
93{
94 return percpu_counter_sum_positive(&wb->stat[item]);
95}
96
97extern void wb_writeout_inc(struct bdi_writeback *wb);
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102static inline unsigned long wb_stat_error(void)
103{
104#ifdef CONFIG_SMP
105 return nr_cpu_ids * WB_STAT_BATCH;
106#else
107 return 1;
108#endif
109}
110
111int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
112int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
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134#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
135#define BDI_CAP_NO_WRITEBACK 0x00000002
136#define BDI_CAP_NO_ACCT_WB 0x00000004
137#define BDI_CAP_STABLE_WRITES 0x00000008
138#define BDI_CAP_STRICTLIMIT 0x00000010
139#define BDI_CAP_CGROUP_WRITEBACK 0x00000020
140#define BDI_CAP_SYNCHRONOUS_IO 0x00000040
141
142#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
143 (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
144
145extern struct backing_dev_info noop_backing_dev_info;
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153
154static inline bool writeback_in_progress(struct bdi_writeback *wb)
155{
156 return test_bit(WB_writeback_running, &wb->state);
157}
158
159static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
160{
161 struct super_block *sb;
162
163 if (!inode)
164 return &noop_backing_dev_info;
165
166 sb = inode->i_sb;
167#ifdef CONFIG_BLOCK
168 if (sb_is_blkdev_sb(sb))
169 return I_BDEV(inode)->bd_bdi;
170#endif
171 return sb->s_bdi;
172}
173
174static inline int wb_congested(struct bdi_writeback *wb, int cong_bits)
175{
176 struct backing_dev_info *bdi = wb->bdi;
177
178 if (bdi->congested_fn)
179 return bdi->congested_fn(bdi->congested_data, cong_bits);
180 return wb->congested->state & cong_bits;
181}
182
183long congestion_wait(int sync, long timeout);
184long wait_iff_congested(int sync, long timeout);
185
186static inline bool bdi_cap_synchronous_io(struct backing_dev_info *bdi)
187{
188 return bdi->capabilities & BDI_CAP_SYNCHRONOUS_IO;
189}
190
191static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi)
192{
193 return bdi->capabilities & BDI_CAP_STABLE_WRITES;
194}
195
196static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)
197{
198 return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);
199}
200
201static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)
202{
203 return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);
204}
205
206static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)
207{
208
209 return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |
210 BDI_CAP_NO_WRITEBACK));
211}
212
213static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
214{
215 return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host));
216}
217
218static inline bool mapping_cap_account_dirty(struct address_space *mapping)
219{
220 return bdi_cap_account_dirty(inode_to_bdi(mapping->host));
221}
222
223static inline int bdi_sched_wait(void *word)
224{
225 schedule();
226 return 0;
227}
228
229#ifdef CONFIG_CGROUP_WRITEBACK
230
231struct bdi_writeback_congested *
232wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp);
233void wb_congested_put(struct bdi_writeback_congested *congested);
234struct bdi_writeback *wb_get_lookup(struct backing_dev_info *bdi,
235 struct cgroup_subsys_state *memcg_css);
236struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
237 struct cgroup_subsys_state *memcg_css,
238 gfp_t gfp);
239void wb_memcg_offline(struct mem_cgroup *memcg);
240void wb_blkcg_offline(struct blkcg *blkcg);
241int inode_congested(struct inode *inode, int cong_bits);
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254static inline bool inode_cgwb_enabled(struct inode *inode)
255{
256 struct backing_dev_info *bdi = inode_to_bdi(inode);
257
258 return cgroup_subsys_on_dfl(memory_cgrp_subsys) &&
259 cgroup_subsys_on_dfl(io_cgrp_subsys) &&
260 bdi_cap_account_dirty(bdi) &&
261 (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
262 (inode->i_sb->s_iflags & SB_I_CGROUPWB);
263}
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273static 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;
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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);
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288 if (likely(wb && wb->blkcg_css == task_css(current, io_cgrp_id)))
289 return wb;
290 return NULL;
291}
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302static inline struct bdi_writeback *
303wb_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}
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330static inline bool inode_to_wb_is_valid(struct inode *inode)
331{
332 return inode->i_wb;
333}
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343static inline struct bdi_writeback *inode_to_wb(const struct inode *inode)
344{
345#ifdef CONFIG_LOCKDEP
346 WARN_ON_ONCE(debug_locks &&
347 (!lockdep_is_held(&inode->i_lock) &&
348 !lockdep_is_held(&inode->i_mapping->i_pages.xa_lock) &&
349 !lockdep_is_held(&inode->i_wb->list_lock)));
350#endif
351 return inode->i_wb;
352}
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369static inline struct bdi_writeback *
370unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie)
371{
372 rcu_read_lock();
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378 cookie->locked = smp_load_acquire(&inode->i_state) & I_WB_SWITCH;
379
380 if (unlikely(cookie->locked))
381 xa_lock_irqsave(&inode->i_mapping->i_pages, cookie->flags);
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387 return inode->i_wb;
388}
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395static inline void unlocked_inode_to_wb_end(struct inode *inode,
396 struct wb_lock_cookie *cookie)
397{
398 if (unlikely(cookie->locked))
399 xa_unlock_irqrestore(&inode->i_mapping->i_pages, cookie->flags);
400
401 rcu_read_unlock();
402}
403
404#else
405
406static inline bool inode_cgwb_enabled(struct inode *inode)
407{
408 return false;
409}
410
411static inline struct bdi_writeback_congested *
412wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp)
413{
414 refcount_inc(&bdi->wb_congested->refcnt);
415 return bdi->wb_congested;
416}
417
418static inline void wb_congested_put(struct bdi_writeback_congested *congested)
419{
420 if (refcount_dec_and_test(&congested->refcnt))
421 kfree(congested);
422}
423
424static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi)
425{
426 return &bdi->wb;
427}
428
429static inline struct bdi_writeback *
430wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp)
431{
432 return &bdi->wb;
433}
434
435static inline bool inode_to_wb_is_valid(struct inode *inode)
436{
437 return true;
438}
439
440static inline struct bdi_writeback *inode_to_wb(struct inode *inode)
441{
442 return &inode_to_bdi(inode)->wb;
443}
444
445static inline struct bdi_writeback *
446unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie)
447{
448 return inode_to_wb(inode);
449}
450
451static inline void unlocked_inode_to_wb_end(struct inode *inode,
452 struct wb_lock_cookie *cookie)
453{
454}
455
456static inline void wb_memcg_offline(struct mem_cgroup *memcg)
457{
458}
459
460static inline void wb_blkcg_offline(struct blkcg *blkcg)
461{
462}
463
464static inline int inode_congested(struct inode *inode, int cong_bits)
465{
466 return wb_congested(&inode_to_bdi(inode)->wb, cong_bits);
467}
468
469#endif
470
471static inline int inode_read_congested(struct inode *inode)
472{
473 return inode_congested(inode, 1 << WB_sync_congested);
474}
475
476static inline int inode_write_congested(struct inode *inode)
477{
478 return inode_congested(inode, 1 << WB_async_congested);
479}
480
481static inline int inode_rw_congested(struct inode *inode)
482{
483 return inode_congested(inode, (1 << WB_sync_congested) |
484 (1 << WB_async_congested));
485}
486
487static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits)
488{
489 return wb_congested(&bdi->wb, cong_bits);
490}
491
492static inline int bdi_read_congested(struct backing_dev_info *bdi)
493{
494 return bdi_congested(bdi, 1 << WB_sync_congested);
495}
496
497static inline int bdi_write_congested(struct backing_dev_info *bdi)
498{
499 return bdi_congested(bdi, 1 << WB_async_congested);
500}
501
502static inline int bdi_rw_congested(struct backing_dev_info *bdi)
503{
504 return bdi_congested(bdi, (1 << WB_sync_congested) |
505 (1 << WB_async_congested));
506}
507
508const char *bdi_dev_name(struct backing_dev_info *bdi);
509
510#endif
511