1
2#ifndef __LINUX_BACKING_DEV_DEFS_H
3#define __LINUX_BACKING_DEV_DEFS_H
4
5#include <linux/list.h>
6#include <linux/radix-tree.h>
7#include <linux/rbtree.h>
8#include <linux/spinlock.h>
9#include <linux/percpu_counter.h>
10#include <linux/percpu-refcount.h>
11#include <linux/flex_proportions.h>
12#include <linux/timer.h>
13#include <linux/workqueue.h>
14#include <linux/kref.h>
15#include <linux/refcount.h>
16
17struct page;
18struct device;
19struct dentry;
20
21
22
23
24enum wb_state {
25 WB_registered,
26 WB_writeback_running,
27 WB_has_dirty_io,
28 WB_start_all,
29};
30
31enum wb_congested_state {
32 WB_async_congested,
33 WB_sync_congested,
34};
35
36typedef int (congested_fn)(void *, int);
37
38enum wb_stat_item {
39 WB_RECLAIMABLE,
40 WB_WRITEBACK,
41 WB_DIRTIED,
42 WB_WRITTEN,
43 NR_WB_STAT_ITEMS
44};
45
46#define WB_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
47
48
49
50
51enum wb_reason {
52 WB_REASON_BACKGROUND,
53 WB_REASON_VMSCAN,
54 WB_REASON_SYNC,
55 WB_REASON_PERIODIC,
56 WB_REASON_LAPTOP_TIMER,
57 WB_REASON_FREE_MORE_MEM,
58 WB_REASON_FS_FREE_SPACE,
59
60
61
62
63
64
65 WB_REASON_FORKER_THREAD,
66 WB_REASON_FOREIGN_FLUSH,
67
68 WB_REASON_MAX,
69};
70
71struct wb_completion {
72 atomic_t cnt;
73 wait_queue_head_t *waitq;
74};
75
76#define __WB_COMPLETION_INIT(_waitq) \
77 (struct wb_completion){ .cnt = ATOMIC_INIT(1), .waitq = (_waitq) }
78
79
80
81
82
83
84
85
86#define WB_COMPLETION_INIT(bdi) __WB_COMPLETION_INIT(&(bdi)->wb_waitq)
87
88#define DEFINE_WB_COMPLETION(cmpl, bdi) \
89 struct wb_completion cmpl = WB_COMPLETION_INIT(bdi)
90
91
92
93
94
95
96
97
98struct bdi_writeback_congested {
99 unsigned long state;
100 refcount_t refcnt;
101
102#ifdef CONFIG_CGROUP_WRITEBACK
103 struct backing_dev_info *__bdi;
104
105
106 int blkcg_id;
107 struct rb_node rb_node;
108#endif
109};
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130struct bdi_writeback {
131 struct backing_dev_info *bdi;
132
133 unsigned long state;
134 unsigned long last_old_flush;
135
136 struct list_head b_dirty;
137 struct list_head b_io;
138 struct list_head b_more_io;
139 struct list_head b_dirty_time;
140 spinlock_t list_lock;
141
142 struct percpu_counter stat[NR_WB_STAT_ITEMS];
143
144 struct bdi_writeback_congested *congested;
145
146 unsigned long bw_time_stamp;
147 unsigned long dirtied_stamp;
148 unsigned long written_stamp;
149 unsigned long write_bandwidth;
150 unsigned long avg_write_bandwidth;
151
152
153
154
155
156
157
158 unsigned long dirty_ratelimit;
159 unsigned long balanced_dirty_ratelimit;
160
161 struct fprop_local_percpu completions;
162 int dirty_exceeded;
163 enum wb_reason start_all_reason;
164
165 spinlock_t work_lock;
166 struct list_head work_list;
167 struct delayed_work dwork;
168
169 unsigned long dirty_sleep;
170
171 struct list_head bdi_node;
172
173#ifdef CONFIG_CGROUP_WRITEBACK
174 struct percpu_ref refcnt;
175 struct fprop_local_percpu memcg_completions;
176 struct cgroup_subsys_state *memcg_css;
177 struct cgroup_subsys_state *blkcg_css;
178 struct list_head memcg_node;
179 struct list_head blkcg_node;
180
181 union {
182 struct work_struct release_work;
183 struct rcu_head rcu;
184 };
185#endif
186};
187
188struct backing_dev_info {
189 u64 id;
190 struct rb_node rb_node;
191 struct list_head bdi_list;
192 unsigned long ra_pages;
193 unsigned long io_pages;
194 congested_fn *congested_fn;
195 void *congested_data;
196
197 const char *name;
198
199 struct kref refcnt;
200 unsigned int capabilities;
201 unsigned int min_ratio;
202 unsigned int max_ratio, max_prop_frac;
203
204
205
206
207
208 atomic_long_t tot_write_bandwidth;
209
210 struct bdi_writeback wb;
211 struct list_head wb_list;
212#ifdef CONFIG_CGROUP_WRITEBACK
213 struct radix_tree_root cgwb_tree;
214 struct rb_root cgwb_congested_tree;
215 struct mutex cgwb_release_mutex;
216 struct rw_semaphore wb_switch_rwsem;
217#else
218 struct bdi_writeback_congested *wb_congested;
219#endif
220 wait_queue_head_t wb_waitq;
221
222 struct device *dev;
223 struct device *owner;
224
225 struct timer_list laptop_mode_wb_timer;
226
227#ifdef CONFIG_DEBUG_FS
228 struct dentry *debug_dir;
229#endif
230};
231
232enum {
233 BLK_RW_ASYNC = 0,
234 BLK_RW_SYNC = 1,
235};
236
237void clear_wb_congested(struct bdi_writeback_congested *congested, int sync);
238void set_wb_congested(struct bdi_writeback_congested *congested, int sync);
239
240static inline void clear_bdi_congested(struct backing_dev_info *bdi, int sync)
241{
242 clear_wb_congested(bdi->wb.congested, sync);
243}
244
245static inline void set_bdi_congested(struct backing_dev_info *bdi, int sync)
246{
247 set_wb_congested(bdi->wb.congested, sync);
248}
249
250struct wb_lock_cookie {
251 bool locked;
252 unsigned long flags;
253};
254
255#ifdef CONFIG_CGROUP_WRITEBACK
256
257
258
259
260
261static inline bool wb_tryget(struct bdi_writeback *wb)
262{
263 if (wb != &wb->bdi->wb)
264 return percpu_ref_tryget(&wb->refcnt);
265 return true;
266}
267
268
269
270
271
272static inline void wb_get(struct bdi_writeback *wb)
273{
274 if (wb != &wb->bdi->wb)
275 percpu_ref_get(&wb->refcnt);
276}
277
278
279
280
281
282static inline void wb_put(struct bdi_writeback *wb)
283{
284 if (WARN_ON_ONCE(!wb->bdi)) {
285
286
287
288
289 return;
290 }
291
292 if (wb != &wb->bdi->wb)
293 percpu_ref_put(&wb->refcnt);
294}
295
296
297
298
299
300
301
302static inline bool wb_dying(struct bdi_writeback *wb)
303{
304 return percpu_ref_is_dying(&wb->refcnt);
305}
306
307#else
308
309static inline bool wb_tryget(struct bdi_writeback *wb)
310{
311 return true;
312}
313
314static inline void wb_get(struct bdi_writeback *wb)
315{
316}
317
318static inline void wb_put(struct bdi_writeback *wb)
319{
320}
321
322static inline bool wb_dying(struct bdi_writeback *wb)
323{
324 return false;
325}
326
327#endif
328
329#endif
330