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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);
36void bdi_set_owner(struct backing_dev_info *bdi, struct device *owner);
37void bdi_unregister(struct backing_dev_info *bdi);
38
39struct backing_dev_info *bdi_alloc(int node_id);
40
41void wb_start_background_writeback(struct bdi_writeback *wb);
42void wb_workfn(struct work_struct *work);
43void wb_wakeup_delayed(struct bdi_writeback *wb);
44
45void wb_wait_for_completion(struct wb_completion *done);
46
47extern spinlock_t bdi_lock;
48extern struct list_head bdi_list;
49
50extern struct workqueue_struct *bdi_wq;
51extern struct workqueue_struct *bdi_async_bio_wq;
52
53static inline bool wb_has_dirty_io(struct bdi_writeback *wb)
54{
55 return test_bit(WB_has_dirty_io, &wb->state);
56}
57
58static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi)
59{
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64 return atomic_long_read(&bdi->tot_write_bandwidth);
65}
66
67static inline void __add_wb_stat(struct bdi_writeback *wb,
68 enum wb_stat_item item, s64 amount)
69{
70 percpu_counter_add_batch(&wb->stat[item], amount, WB_STAT_BATCH);
71}
72
73static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
74{
75 __add_wb_stat(wb, item, 1);
76}
77
78static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
79{
80 __add_wb_stat(wb, item, -1);
81}
82
83static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
84{
85 return percpu_counter_read_positive(&wb->stat[item]);
86}
87
88static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item)
89{
90 return percpu_counter_sum_positive(&wb->stat[item]);
91}
92
93extern void wb_writeout_inc(struct bdi_writeback *wb);
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98static inline unsigned long wb_stat_error(void)
99{
100#ifdef CONFIG_SMP
101 return nr_cpu_ids * WB_STAT_BATCH;
102#else
103 return 1;
104#endif
105}
106
107int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
108int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
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130#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
131#define BDI_CAP_NO_WRITEBACK 0x00000002
132#define BDI_CAP_NO_ACCT_WB 0x00000004
133#define BDI_CAP_STABLE_WRITES 0x00000008
134#define BDI_CAP_STRICTLIMIT 0x00000010
135#define BDI_CAP_CGROUP_WRITEBACK 0x00000020
136#define BDI_CAP_SYNCHRONOUS_IO 0x00000040
137
138#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
139 (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
140
141extern struct backing_dev_info noop_backing_dev_info;
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150static inline bool writeback_in_progress(struct bdi_writeback *wb)
151{
152 return test_bit(WB_writeback_running, &wb->state);
153}
154
155static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
156{
157 struct super_block *sb;
158
159 if (!inode)
160 return &noop_backing_dev_info;
161
162 sb = inode->i_sb;
163#ifdef CONFIG_BLOCK
164 if (sb_is_blkdev_sb(sb))
165 return I_BDEV(inode)->bd_bdi;
166#endif
167 return sb->s_bdi;
168}
169
170static inline int wb_congested(struct bdi_writeback *wb, int cong_bits)
171{
172 return wb->congested & cong_bits;
173}
174
175long congestion_wait(int sync, long timeout);
176long wait_iff_congested(int sync, long timeout);
177
178static inline bool bdi_cap_synchronous_io(struct backing_dev_info *bdi)
179{
180 return bdi->capabilities & BDI_CAP_SYNCHRONOUS_IO;
181}
182
183static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi)
184{
185 return bdi->capabilities & BDI_CAP_STABLE_WRITES;
186}
187
188static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)
189{
190 return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);
191}
192
193static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)
194{
195 return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);
196}
197
198static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)
199{
200
201 return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |
202 BDI_CAP_NO_WRITEBACK));
203}
204
205static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
206{
207 return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host));
208}
209
210static inline bool mapping_cap_account_dirty(struct address_space *mapping)
211{
212 return bdi_cap_account_dirty(inode_to_bdi(mapping->host));
213}
214
215static inline int bdi_sched_wait(void *word)
216{
217 schedule();
218 return 0;
219}
220
221#ifdef CONFIG_CGROUP_WRITEBACK
222
223struct bdi_writeback *wb_get_lookup(struct backing_dev_info *bdi,
224 struct cgroup_subsys_state *memcg_css);
225struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
226 struct cgroup_subsys_state *memcg_css,
227 gfp_t gfp);
228void wb_memcg_offline(struct mem_cgroup *memcg);
229void wb_blkcg_offline(struct blkcg *blkcg);
230int inode_congested(struct inode *inode, int cong_bits);
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243static inline bool inode_cgwb_enabled(struct inode *inode)
244{
245 struct backing_dev_info *bdi = inode_to_bdi(inode);
246
247 return cgroup_subsys_on_dfl(memory_cgrp_subsys) &&
248 cgroup_subsys_on_dfl(io_cgrp_subsys) &&
249 bdi_cap_account_dirty(bdi) &&
250 (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
251 (inode->i_sb->s_iflags & SB_I_CGROUPWB);
252}
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262static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi)
263{
264 struct cgroup_subsys_state *memcg_css;
265 struct bdi_writeback *wb;
266
267 memcg_css = task_css(current, memory_cgrp_id);
268 if (!memcg_css->parent)
269 return &bdi->wb;
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271 wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
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277 if (likely(wb && wb->blkcg_css == task_css(current, io_cgrp_id)))
278 return wb;
279 return NULL;
280}
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291static inline struct bdi_writeback *
292wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp)
293{
294 struct bdi_writeback *wb;
295
296 rcu_read_lock();
297 wb = wb_find_current(bdi);
298 if (wb && unlikely(!wb_tryget(wb)))
299 wb = NULL;
300 rcu_read_unlock();
301
302 if (unlikely(!wb)) {
303 struct cgroup_subsys_state *memcg_css;
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305 memcg_css = task_get_css(current, memory_cgrp_id);
306 wb = wb_get_create(bdi, memcg_css, gfp);
307 css_put(memcg_css);
308 }
309 return wb;
310}
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319static inline bool inode_to_wb_is_valid(struct inode *inode)
320{
321 return inode->i_wb;
322}
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332static inline struct bdi_writeback *inode_to_wb(const struct inode *inode)
333{
334#ifdef CONFIG_LOCKDEP
335 WARN_ON_ONCE(debug_locks &&
336 (!lockdep_is_held(&inode->i_lock) &&
337 !lockdep_is_held(&inode->i_mapping->i_pages.xa_lock) &&
338 !lockdep_is_held(&inode->i_wb->list_lock)));
339#endif
340 return inode->i_wb;
341}
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358static inline struct bdi_writeback *
359unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie)
360{
361 rcu_read_lock();
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367 cookie->locked = smp_load_acquire(&inode->i_state) & I_WB_SWITCH;
368
369 if (unlikely(cookie->locked))
370 xa_lock_irqsave(&inode->i_mapping->i_pages, cookie->flags);
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376 return inode->i_wb;
377}
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384static inline void unlocked_inode_to_wb_end(struct inode *inode,
385 struct wb_lock_cookie *cookie)
386{
387 if (unlikely(cookie->locked))
388 xa_unlock_irqrestore(&inode->i_mapping->i_pages, cookie->flags);
389
390 rcu_read_unlock();
391}
392
393#else
394
395static inline bool inode_cgwb_enabled(struct inode *inode)
396{
397 return false;
398}
399
400static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi)
401{
402 return &bdi->wb;
403}
404
405static inline struct bdi_writeback *
406wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp)
407{
408 return &bdi->wb;
409}
410
411static inline bool inode_to_wb_is_valid(struct inode *inode)
412{
413 return true;
414}
415
416static inline struct bdi_writeback *inode_to_wb(struct inode *inode)
417{
418 return &inode_to_bdi(inode)->wb;
419}
420
421static inline struct bdi_writeback *
422unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie)
423{
424 return inode_to_wb(inode);
425}
426
427static inline void unlocked_inode_to_wb_end(struct inode *inode,
428 struct wb_lock_cookie *cookie)
429{
430}
431
432static inline void wb_memcg_offline(struct mem_cgroup *memcg)
433{
434}
435
436static inline void wb_blkcg_offline(struct blkcg *blkcg)
437{
438}
439
440static inline int inode_congested(struct inode *inode, int cong_bits)
441{
442 return wb_congested(&inode_to_bdi(inode)->wb, cong_bits);
443}
444
445#endif
446
447static inline int inode_read_congested(struct inode *inode)
448{
449 return inode_congested(inode, 1 << WB_sync_congested);
450}
451
452static inline int inode_write_congested(struct inode *inode)
453{
454 return inode_congested(inode, 1 << WB_async_congested);
455}
456
457static inline int inode_rw_congested(struct inode *inode)
458{
459 return inode_congested(inode, (1 << WB_sync_congested) |
460 (1 << WB_async_congested));
461}
462
463static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits)
464{
465 return wb_congested(&bdi->wb, cong_bits);
466}
467
468static inline int bdi_read_congested(struct backing_dev_info *bdi)
469{
470 return bdi_congested(bdi, 1 << WB_sync_congested);
471}
472
473static inline int bdi_write_congested(struct backing_dev_info *bdi)
474{
475 return bdi_congested(bdi, 1 << WB_async_congested);
476}
477
478static inline int bdi_rw_congested(struct backing_dev_info *bdi)
479{
480 return bdi_congested(bdi, (1 << WB_sync_congested) |
481 (1 << WB_async_congested));
482}
483
484const char *bdi_dev_name(struct backing_dev_info *bdi);
485
486#endif
487