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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_wb_alloc,
32 BDI_async_congested,
33 BDI_sync_congested,
34 BDI_registered,
35 BDI_writeback_running,
36 BDI_unused,
37};
38
39typedef int (congested_fn)(void *, int);
40
41enum bdi_stat_item {
42 BDI_RECLAIMABLE,
43 BDI_WRITEBACK,
44 BDI_DIRTIED,
45 BDI_WRITTEN,
46 NR_BDI_STAT_ITEMS
47};
48
49#define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
50
51struct bdi_writeback {
52 struct backing_dev_info *bdi;
53 unsigned int nr;
54
55 unsigned long last_old_flush;
56
57 struct delayed_work dwork;
58 struct list_head b_dirty;
59 struct list_head b_io;
60 struct list_head b_more_io;
61 spinlock_t list_lock;
62};
63
64struct backing_dev_info {
65 struct list_head bdi_list;
66 unsigned long ra_pages;
67 unsigned long state;
68 unsigned int capabilities;
69 congested_fn *congested_fn;
70 void *congested_data;
71
72 char *name;
73
74 struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS];
75
76 unsigned long bw_time_stamp;
77 unsigned long dirtied_stamp;
78 unsigned long written_stamp;
79 unsigned long write_bandwidth;
80 unsigned long avg_write_bandwidth;
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87
88 unsigned long dirty_ratelimit;
89 unsigned long balanced_dirty_ratelimit;
90
91 struct fprop_local_percpu completions;
92 int dirty_exceeded;
93
94 unsigned int min_ratio;
95 unsigned int max_ratio, max_prop_frac;
96
97 struct bdi_writeback wb;
98 spinlock_t wb_lock;
99
100 struct list_head work_list;
101
102 struct device *dev;
103
104 struct timer_list laptop_mode_wb_timer;
105
106#ifdef CONFIG_DEBUG_FS
107 struct dentry *debug_dir;
108 struct dentry *debug_stats;
109#endif
110};
111
112int 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);
119void bdi_unregister(struct backing_dev_info *bdi);
120int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int);
121void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
122 enum wb_reason reason);
123void bdi_start_background_writeback(struct backing_dev_info *bdi);
124void bdi_writeback_workfn(struct work_struct *work);
125int bdi_has_dirty_io(struct backing_dev_info *bdi);
126void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi);
127void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2);
128
129extern spinlock_t bdi_lock;
130extern struct list_head bdi_list;
131
132extern struct workqueue_struct *bdi_wq;
133
134static inline int wb_has_dirty_io(struct bdi_writeback *wb)
135{
136 return !list_empty(&wb->b_dirty) ||
137 !list_empty(&wb->b_io) ||
138 !list_empty(&wb->b_more_io);
139}
140
141static inline void __add_bdi_stat(struct backing_dev_info *bdi,
142 enum bdi_stat_item item, s64 amount)
143{
144 __percpu_counter_add(&bdi->bdi_stat[item], amount, BDI_STAT_BATCH);
145}
146
147static inline void __inc_bdi_stat(struct backing_dev_info *bdi,
148 enum bdi_stat_item item)
149{
150 __add_bdi_stat(bdi, item, 1);
151}
152
153static inline void inc_bdi_stat(struct backing_dev_info *bdi,
154 enum bdi_stat_item item)
155{
156 unsigned long flags;
157
158 local_irq_save(flags);
159 __inc_bdi_stat(bdi, item);
160 local_irq_restore(flags);
161}
162
163static inline void __dec_bdi_stat(struct backing_dev_info *bdi,
164 enum bdi_stat_item item)
165{
166 __add_bdi_stat(bdi, item, -1);
167}
168
169static inline void dec_bdi_stat(struct backing_dev_info *bdi,
170 enum bdi_stat_item item)
171{
172 unsigned long flags;
173
174 local_irq_save(flags);
175 __dec_bdi_stat(bdi, item);
176 local_irq_restore(flags);
177}
178
179static inline s64 bdi_stat(struct backing_dev_info *bdi,
180 enum bdi_stat_item item)
181{
182 return percpu_counter_read_positive(&bdi->bdi_stat[item]);
183}
184
185static inline s64 __bdi_stat_sum(struct backing_dev_info *bdi,
186 enum bdi_stat_item item)
187{
188 return percpu_counter_sum_positive(&bdi->bdi_stat[item]);
189}
190
191static inline s64 bdi_stat_sum(struct backing_dev_info *bdi,
192 enum bdi_stat_item item)
193{
194 s64 sum;
195 unsigned long flags;
196
197 local_irq_save(flags);
198 sum = __bdi_stat_sum(bdi, item);
199 local_irq_restore(flags);
200
201 return sum;
202}
203
204extern void bdi_writeout_inc(struct backing_dev_info *bdi);
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209static inline unsigned long bdi_stat_error(struct backing_dev_info *bdi)
210{
211#ifdef CONFIG_SMP
212 return nr_cpu_ids * BDI_STAT_BATCH;
213#else
214 return 1;
215#endif
216}
217
218int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);
219int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
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249#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
250#define BDI_CAP_NO_WRITEBACK 0x00000002
251#define BDI_CAP_MAP_COPY 0x00000004
252#define BDI_CAP_MAP_DIRECT 0x00000008
253#define BDI_CAP_READ_MAP 0x00000010
254#define BDI_CAP_WRITE_MAP 0x00000020
255#define BDI_CAP_EXEC_MAP 0x00000040
256#define BDI_CAP_NO_ACCT_WB 0x00000080
257#define BDI_CAP_SWAP_BACKED 0x00000100
258#define BDI_CAP_STABLE_WRITES 0x00000200
259#define BDI_CAP_STRICTLIMIT 0x00000400
260
261#define BDI_CAP_VMFLAGS \
262 (BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP)
263
264#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
265 (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
266
267#if defined(VM_MAYREAD) && \
268 (BDI_CAP_READ_MAP != VM_MAYREAD || \
269 BDI_CAP_WRITE_MAP != VM_MAYWRITE || \
270 BDI_CAP_EXEC_MAP != VM_MAYEXEC)
271#error please change backing_dev_info::capabilities flags
272#endif
273
274extern struct backing_dev_info default_backing_dev_info;
275extern struct backing_dev_info noop_backing_dev_info;
276
277int writeback_in_progress(struct backing_dev_info *bdi);
278
279static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits)
280{
281 if (bdi->congested_fn)
282 return bdi->congested_fn(bdi->congested_data, bdi_bits);
283 return (bdi->state & bdi_bits);
284}
285
286static inline int bdi_read_congested(struct backing_dev_info *bdi)
287{
288 return bdi_congested(bdi, 1 << BDI_sync_congested);
289}
290
291static inline int bdi_write_congested(struct backing_dev_info *bdi)
292{
293 return bdi_congested(bdi, 1 << BDI_async_congested);
294}
295
296static inline int bdi_rw_congested(struct backing_dev_info *bdi)
297{
298 return bdi_congested(bdi, (1 << BDI_sync_congested) |
299 (1 << BDI_async_congested));
300}
301
302enum {
303 BLK_RW_ASYNC = 0,
304 BLK_RW_SYNC = 1,
305};
306
307void clear_bdi_congested(struct backing_dev_info *bdi, int sync);
308void set_bdi_congested(struct backing_dev_info *bdi, int sync);
309long congestion_wait(int sync, long timeout);
310long wait_iff_congested(struct zone *zone, int sync, long timeout);
311int pdflush_proc_obsolete(struct ctl_table *table, int write,
312 void __user *buffer, size_t *lenp, loff_t *ppos);
313
314static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi)
315{
316 return bdi->capabilities & BDI_CAP_STABLE_WRITES;
317}
318
319static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)
320{
321 return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);
322}
323
324static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)
325{
326 return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);
327}
328
329static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)
330{
331
332 return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |
333 BDI_CAP_NO_WRITEBACK));
334}
335
336static inline bool bdi_cap_swap_backed(struct backing_dev_info *bdi)
337{
338 return bdi->capabilities & BDI_CAP_SWAP_BACKED;
339}
340
341static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
342{
343 return bdi_cap_writeback_dirty(mapping->backing_dev_info);
344}
345
346static inline bool mapping_cap_account_dirty(struct address_space *mapping)
347{
348 return bdi_cap_account_dirty(mapping->backing_dev_info);
349}
350
351static inline bool mapping_cap_swap_backed(struct address_space *mapping)
352{
353 return bdi_cap_swap_backed(mapping->backing_dev_info);
354}
355
356static inline int bdi_sched_wait(void *word)
357{
358 schedule();
359 return 0;
360}
361
362#endif
363