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8#ifndef _LINUX_BACKING_DEV_H
9#define _LINUX_BACKING_DEV_H
10
11#include <linux/kernel.h>
12#include <linux/fs.h>
13#include <linux/sched.h>
14#include <linux/blkdev.h>
15#include <linux/writeback.h>
16#include <linux/blk-cgroup.h>
17#include <linux/backing-dev-defs.h>
18#include <linux/slab.h>
19
20static inline struct backing_dev_info *bdi_get(struct backing_dev_info *bdi)
21{
22 kref_get(&bdi->refcnt);
23 return bdi;
24}
25
26void bdi_put(struct backing_dev_info *bdi);
27
28__printf(2, 3)
29int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...);
30int bdi_register_va(struct backing_dev_info *bdi, const char *fmt,
31 va_list args);
32int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner);
33void bdi_unregister(struct backing_dev_info *bdi);
34
35struct backing_dev_info *bdi_alloc_node(gfp_t gfp_mask, int node_id);
36static inline struct backing_dev_info *bdi_alloc(gfp_t gfp_mask)
37{
38 return bdi_alloc_node(gfp_mask, NUMA_NO_NODE);
39}
40
41void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,
42 bool range_cyclic, enum wb_reason reason);
43void wb_start_background_writeback(struct bdi_writeback *wb);
44void wb_workfn(struct work_struct *work);
45void wb_wakeup_delayed(struct bdi_writeback *wb);
46
47extern spinlock_t bdi_lock;
48extern struct list_head bdi_list;
49
50extern struct workqueue_struct *bdi_wq;
51
52static inline bool wb_has_dirty_io(struct bdi_writeback *wb)
53{
54 return test_bit(WB_has_dirty_io, &wb->state);
55}
56
57static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi)
58{
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63 return atomic_long_read(&bdi->tot_write_bandwidth);
64}
65
66static inline void __add_wb_stat(struct bdi_writeback *wb,
67 enum wb_stat_item item, s64 amount)
68{
69 percpu_counter_add_batch(&wb->stat[item], amount, WB_STAT_BATCH);
70}
71
72static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
73{
74 __add_wb_stat(wb, item, 1);
75}
76
77static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
78{
79 __add_wb_stat(wb, item, -1);
80}
81
82static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
83{
84 return percpu_counter_read_positive(&wb->stat[item]);
85}
86
87static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item)
88{
89 return percpu_counter_sum_positive(&wb->stat[item]);
90}
91
92extern void wb_writeout_inc(struct bdi_writeback *wb);
93
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96
97static inline unsigned long wb_stat_error(struct bdi_writeback *wb)
98{
99#ifdef CONFIG_SMP
100 return nr_cpu_ids * WB_STAT_BATCH;
101#else
102 return 1;
103#endif
104}
105
106int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
107int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
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127#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
128#define BDI_CAP_NO_WRITEBACK 0x00000002
129#define BDI_CAP_NO_ACCT_WB 0x00000004
130#define BDI_CAP_STABLE_WRITES 0x00000008
131#define BDI_CAP_STRICTLIMIT 0x00000010
132#define BDI_CAP_CGROUP_WRITEBACK 0x00000020
133
134#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
135 (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
136
137extern struct backing_dev_info noop_backing_dev_info;
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146static inline bool writeback_in_progress(struct bdi_writeback *wb)
147{
148 return test_bit(WB_writeback_running, &wb->state);
149}
150
151static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
152{
153 struct super_block *sb;
154
155 if (!inode)
156 return &noop_backing_dev_info;
157
158 sb = inode->i_sb;
159#ifdef CONFIG_BLOCK
160 if (sb_is_blkdev_sb(sb))
161 return I_BDEV(inode)->bd_bdi;
162#endif
163 return sb->s_bdi;
164}
165
166static inline int wb_congested(struct bdi_writeback *wb, int cong_bits)
167{
168 struct backing_dev_info *bdi = wb->bdi;
169
170 if (bdi->congested_fn)
171 return bdi->congested_fn(bdi->congested_data, cong_bits);
172 return wb->congested->state & cong_bits;
173}
174
175long congestion_wait(int sync, long timeout);
176long wait_iff_congested(struct pglist_data *pgdat, int sync, long timeout);
177int pdflush_proc_obsolete(struct ctl_table *table, int write,
178 void __user *buffer, size_t *lenp, loff_t *ppos);
179
180static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi)
181{
182 return bdi->capabilities & BDI_CAP_STABLE_WRITES;
183}
184
185static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)
186{
187 return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);
188}
189
190static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)
191{
192 return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);
193}
194
195static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)
196{
197
198 return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |
199 BDI_CAP_NO_WRITEBACK));
200}
201
202static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
203{
204 return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host));
205}
206
207static inline bool mapping_cap_account_dirty(struct address_space *mapping)
208{
209 return bdi_cap_account_dirty(inode_to_bdi(mapping->host));
210}
211
212static inline int bdi_sched_wait(void *word)
213{
214 schedule();
215 return 0;
216}
217
218#ifdef CONFIG_CGROUP_WRITEBACK
219
220struct bdi_writeback_congested *
221wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp);
222void wb_congested_put(struct bdi_writeback_congested *congested);
223struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
224 struct cgroup_subsys_state *memcg_css,
225 gfp_t gfp);
226void wb_memcg_offline(struct mem_cgroup *memcg);
227void wb_blkcg_offline(struct blkcg *blkcg);
228int inode_congested(struct inode *inode, int cong_bits);
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241static inline bool inode_cgwb_enabled(struct inode *inode)
242{
243 struct backing_dev_info *bdi = inode_to_bdi(inode);
244
245 return cgroup_subsys_on_dfl(memory_cgrp_subsys) &&
246 cgroup_subsys_on_dfl(io_cgrp_subsys) &&
247 bdi_cap_account_dirty(bdi) &&
248 (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
249 (inode->i_sb->s_iflags & SB_I_CGROUPWB);
250}
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260static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi)
261{
262 struct cgroup_subsys_state *memcg_css;
263 struct bdi_writeback *wb;
264
265 memcg_css = task_css(current, memory_cgrp_id);
266 if (!memcg_css->parent)
267 return &bdi->wb;
268
269 wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
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275 if (likely(wb && wb->blkcg_css == task_css(current, io_cgrp_id)))
276 return wb;
277 return NULL;
278}
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289static inline struct bdi_writeback *
290wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp)
291{
292 struct bdi_writeback *wb;
293
294 rcu_read_lock();
295 wb = wb_find_current(bdi);
296 if (wb && unlikely(!wb_tryget(wb)))
297 wb = NULL;
298 rcu_read_unlock();
299
300 if (unlikely(!wb)) {
301 struct cgroup_subsys_state *memcg_css;
302
303 memcg_css = task_get_css(current, memory_cgrp_id);
304 wb = wb_get_create(bdi, memcg_css, gfp);
305 css_put(memcg_css);
306 }
307 return wb;
308}
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317static inline bool inode_to_wb_is_valid(struct inode *inode)
318{
319 return inode->i_wb;
320}
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330static inline struct bdi_writeback *inode_to_wb(struct inode *inode)
331{
332#ifdef CONFIG_LOCKDEP
333 WARN_ON_ONCE(debug_locks &&
334 (!lockdep_is_held(&inode->i_lock) &&
335 !lockdep_is_held(&inode->i_mapping->tree_lock) &&
336 !lockdep_is_held(&inode->i_wb->list_lock)));
337#endif
338 return inode->i_wb;
339}
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356static inline struct bdi_writeback *
357unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp)
358{
359 rcu_read_lock();
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365 *lockedp = smp_load_acquire(&inode->i_state) & I_WB_SWITCH;
366
367 if (unlikely(*lockedp))
368 spin_lock_irq(&inode->i_mapping->tree_lock);
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374 return inode->i_wb;
375}
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382static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked)
383{
384 if (unlikely(locked))
385 spin_unlock_irq(&inode->i_mapping->tree_lock);
386
387 rcu_read_unlock();
388}
389
390#else
391
392static inline bool inode_cgwb_enabled(struct inode *inode)
393{
394 return false;
395}
396
397static inline struct bdi_writeback_congested *
398wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp)
399{
400 atomic_inc(&bdi->wb_congested->refcnt);
401 return bdi->wb_congested;
402}
403
404static inline void wb_congested_put(struct bdi_writeback_congested *congested)
405{
406 if (atomic_dec_and_test(&congested->refcnt))
407 kfree(congested);
408}
409
410static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi)
411{
412 return &bdi->wb;
413}
414
415static inline struct bdi_writeback *
416wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp)
417{
418 return &bdi->wb;
419}
420
421static inline bool inode_to_wb_is_valid(struct inode *inode)
422{
423 return true;
424}
425
426static inline struct bdi_writeback *inode_to_wb(struct inode *inode)
427{
428 return &inode_to_bdi(inode)->wb;
429}
430
431static inline struct bdi_writeback *
432unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp)
433{
434 return inode_to_wb(inode);
435}
436
437static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked)
438{
439}
440
441static inline void wb_memcg_offline(struct mem_cgroup *memcg)
442{
443}
444
445static inline void wb_blkcg_offline(struct blkcg *blkcg)
446{
447}
448
449static inline int inode_congested(struct inode *inode, int cong_bits)
450{
451 return wb_congested(&inode_to_bdi(inode)->wb, cong_bits);
452}
453
454#endif
455
456static inline int inode_read_congested(struct inode *inode)
457{
458 return inode_congested(inode, 1 << WB_sync_congested);
459}
460
461static inline int inode_write_congested(struct inode *inode)
462{
463 return inode_congested(inode, 1 << WB_async_congested);
464}
465
466static inline int inode_rw_congested(struct inode *inode)
467{
468 return inode_congested(inode, (1 << WB_sync_congested) |
469 (1 << WB_async_congested));
470}
471
472static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits)
473{
474 return wb_congested(&bdi->wb, cong_bits);
475}
476
477static inline int bdi_read_congested(struct backing_dev_info *bdi)
478{
479 return bdi_congested(bdi, 1 << WB_sync_congested);
480}
481
482static inline int bdi_write_congested(struct backing_dev_info *bdi)
483{
484 return bdi_congested(bdi, 1 << WB_async_congested);
485}
486
487static inline int bdi_rw_congested(struct backing_dev_info *bdi)
488{
489 return bdi_congested(bdi, (1 << WB_sync_congested) |
490 (1 << WB_async_congested));
491}
492
493#endif
494