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8#ifndef _LINUX_BACKING_DEV_H
9#define _LINUX_BACKING_DEV_H
10
11#include <linux/percpu_counter.h>
12#include <linux/log2.h>
13#include <linux/flex_proportions.h>
14#include <linux/kernel.h>
15#include <linux/fs.h>
16#include <linux/sched.h>
17#include <linux/timer.h>
18#include <linux/writeback.h>
19#include <linux/atomic.h>
20#include <linux/sysctl.h>
21#include <linux/workqueue.h>
22
23struct page;
24struct device;
25struct dentry;
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29
30enum bdi_state {
31 BDI_async_congested,
32 BDI_sync_congested,
33 BDI_registered,
34 BDI_writeback_running,
35};
36
37typedef int (congested_fn)(void *, int);
38
39enum bdi_stat_item {
40 BDI_RECLAIMABLE,
41 BDI_WRITEBACK,
42 BDI_DIRTIED,
43 BDI_WRITTEN,
44 NR_BDI_STAT_ITEMS
45};
46
47#define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
48
49struct bdi_writeback {
50 struct backing_dev_info *bdi;
51
52 unsigned long last_old_flush;
53
54 struct delayed_work dwork;
55 struct list_head b_dirty;
56 struct list_head b_io;
57 struct list_head b_more_io;
58 struct list_head b_dirty_time;
59 spinlock_t list_lock;
60};
61
62struct backing_dev_info {
63 struct list_head bdi_list;
64 unsigned long ra_pages;
65 unsigned long state;
66 unsigned int capabilities;
67 congested_fn *congested_fn;
68 void *congested_data;
69
70 char *name;
71
72 struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS];
73
74 unsigned long bw_time_stamp;
75 unsigned long dirtied_stamp;
76 unsigned long written_stamp;
77 unsigned long write_bandwidth;
78 unsigned long avg_write_bandwidth;
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85
86 unsigned long dirty_ratelimit;
87 unsigned long balanced_dirty_ratelimit;
88
89 struct fprop_local_percpu completions;
90 int dirty_exceeded;
91
92 unsigned int min_ratio;
93 unsigned int max_ratio, max_prop_frac;
94
95 struct bdi_writeback wb;
96 spinlock_t wb_lock;
97
98 struct list_head work_list;
99
100 struct device *dev;
101
102 struct timer_list laptop_mode_wb_timer;
103
104#ifdef CONFIG_DEBUG_FS
105 struct dentry *debug_dir;
106 struct dentry *debug_stats;
107#endif
108};
109
110struct backing_dev_info *inode_to_bdi(struct inode *inode);
111
112int __must_check bdi_init(struct backing_dev_info *bdi);
113void bdi_destroy(struct backing_dev_info *bdi);
114
115__printf(3, 4)
116int bdi_register(struct backing_dev_info *bdi, struct device *parent,
117 const char *fmt, ...);
118int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
119int __must_check bdi_setup_and_register(struct backing_dev_info *, char *);
120void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
121 enum wb_reason reason);
122void bdi_start_background_writeback(struct backing_dev_info *bdi);
123void bdi_writeback_workfn(struct work_struct *work);
124int bdi_has_dirty_io(struct backing_dev_info *bdi);
125void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi);
126
127extern spinlock_t bdi_lock;
128extern struct list_head bdi_list;
129
130extern struct workqueue_struct *bdi_wq;
131
132static inline int wb_has_dirty_io(struct bdi_writeback *wb)
133{
134 return !list_empty(&wb->b_dirty) ||
135 !list_empty(&wb->b_io) ||
136 !list_empty(&wb->b_more_io);
137}
138
139static inline void __add_bdi_stat(struct backing_dev_info *bdi,
140 enum bdi_stat_item item, s64 amount)
141{
142 __percpu_counter_add(&bdi->bdi_stat[item], amount, BDI_STAT_BATCH);
143}
144
145static inline void __inc_bdi_stat(struct backing_dev_info *bdi,
146 enum bdi_stat_item item)
147{
148 __add_bdi_stat(bdi, item, 1);
149}
150
151static inline void inc_bdi_stat(struct backing_dev_info *bdi,
152 enum bdi_stat_item item)
153{
154 unsigned long flags;
155
156 local_irq_save(flags);
157 __inc_bdi_stat(bdi, item);
158 local_irq_restore(flags);
159}
160
161static inline void __dec_bdi_stat(struct backing_dev_info *bdi,
162 enum bdi_stat_item item)
163{
164 __add_bdi_stat(bdi, item, -1);
165}
166
167static inline void dec_bdi_stat(struct backing_dev_info *bdi,
168 enum bdi_stat_item item)
169{
170 unsigned long flags;
171
172 local_irq_save(flags);
173 __dec_bdi_stat(bdi, item);
174 local_irq_restore(flags);
175}
176
177static inline s64 bdi_stat(struct backing_dev_info *bdi,
178 enum bdi_stat_item item)
179{
180 return percpu_counter_read_positive(&bdi->bdi_stat[item]);
181}
182
183static inline s64 __bdi_stat_sum(struct backing_dev_info *bdi,
184 enum bdi_stat_item item)
185{
186 return percpu_counter_sum_positive(&bdi->bdi_stat[item]);
187}
188
189static inline s64 bdi_stat_sum(struct backing_dev_info *bdi,
190 enum bdi_stat_item item)
191{
192 s64 sum;
193 unsigned long flags;
194
195 local_irq_save(flags);
196 sum = __bdi_stat_sum(bdi, item);
197 local_irq_restore(flags);
198
199 return sum;
200}
201
202extern void bdi_writeout_inc(struct backing_dev_info *bdi);
203
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206
207static inline unsigned long bdi_stat_error(struct backing_dev_info *bdi)
208{
209#ifdef CONFIG_SMP
210 return nr_cpu_ids * BDI_STAT_BATCH;
211#else
212 return 1;
213#endif
214}
215
216int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
217int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
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234
235#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
236#define BDI_CAP_NO_WRITEBACK 0x00000002
237#define BDI_CAP_NO_ACCT_WB 0x00000004
238#define BDI_CAP_STABLE_WRITES 0x00000008
239#define BDI_CAP_STRICTLIMIT 0x00000010
240
241#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
242 (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
243
244extern struct backing_dev_info noop_backing_dev_info;
245
246int writeback_in_progress(struct backing_dev_info *bdi);
247
248static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits)
249{
250 if (bdi->congested_fn)
251 return bdi->congested_fn(bdi->congested_data, bdi_bits);
252 return (bdi->state & bdi_bits);
253}
254
255static inline int bdi_read_congested(struct backing_dev_info *bdi)
256{
257 return bdi_congested(bdi, 1 << BDI_sync_congested);
258}
259
260static inline int bdi_write_congested(struct backing_dev_info *bdi)
261{
262 return bdi_congested(bdi, 1 << BDI_async_congested);
263}
264
265static inline int bdi_rw_congested(struct backing_dev_info *bdi)
266{
267 return bdi_congested(bdi, (1 << BDI_sync_congested) |
268 (1 << BDI_async_congested));
269}
270
271enum {
272 BLK_RW_ASYNC = 0,
273 BLK_RW_SYNC = 1,
274};
275
276void clear_bdi_congested(struct backing_dev_info *bdi, int sync);
277void set_bdi_congested(struct backing_dev_info *bdi, int sync);
278long congestion_wait(int sync, long timeout);
279long wait_iff_congested(struct zone *zone, int sync, long timeout);
280int pdflush_proc_obsolete(struct ctl_table *table, int write,
281 void __user *buffer, size_t *lenp, loff_t *ppos);
282
283static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi)
284{
285 return bdi->capabilities & BDI_CAP_STABLE_WRITES;
286}
287
288static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)
289{
290 return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);
291}
292
293static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)
294{
295 return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);
296}
297
298static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)
299{
300
301 return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |
302 BDI_CAP_NO_WRITEBACK));
303}
304
305static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
306{
307 return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host));
308}
309
310static inline bool mapping_cap_account_dirty(struct address_space *mapping)
311{
312 return bdi_cap_account_dirty(inode_to_bdi(mapping->host));
313}
314
315static inline int bdi_sched_wait(void *word)
316{
317 schedule();
318 return 0;
319}
320
321#endif
322