Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
f30c2269 | 2 | * include/linux/writeback.h |
1da177e4 LT |
3 | */ |
4 | #ifndef WRITEBACK_H | |
5 | #define WRITEBACK_H | |
6 | ||
e8edc6e0 | 7 | #include <linux/sched.h> |
a27bb332 | 8 | #include <linux/workqueue.h> |
f5ff8422 | 9 | #include <linux/fs.h> |
e8edc6e0 | 10 | |
54848d73 WF |
11 | DECLARE_PER_CPU(int, dirty_throttle_leaks); |
12 | ||
ffd1f609 | 13 | /* |
1a12d8bd WF |
14 | * The 1/4 region under the global dirty thresh is for smooth dirty throttling: |
15 | * | |
16 | * (thresh - thresh/DIRTY_FULL_SCOPE, thresh) | |
17 | * | |
ffd1f609 WF |
18 | * Further beyond, all dirtier tasks will enter a loop waiting (possibly long |
19 | * time) for the dirty pages to drop, unless written enough pages. | |
20 | * | |
21 | * The global dirty threshold is normally equal to the global dirty limit, | |
22 | * except when the system suddenly allocates a lot of anonymous memory and | |
23 | * knocks down the global dirty threshold quickly, in which case the global | |
24 | * dirty limit will follow down slowly to prevent livelocking all dirtier tasks. | |
25 | */ | |
1a12d8bd WF |
26 | #define DIRTY_SCOPE 8 |
27 | #define DIRTY_FULL_SCOPE (DIRTY_SCOPE / 2) | |
ffd1f609 | 28 | |
1da177e4 LT |
29 | struct backing_dev_info; |
30 | ||
1da177e4 LT |
31 | /* |
32 | * fs/fs-writeback.c | |
33 | */ | |
34 | enum writeback_sync_modes { | |
35 | WB_SYNC_NONE, /* Don't wait on anything */ | |
36 | WB_SYNC_ALL, /* Wait on every mapping */ | |
1da177e4 LT |
37 | }; |
38 | ||
0e175a18 CW |
39 | /* |
40 | * why some writeback work was initiated | |
41 | */ | |
42 | enum wb_reason { | |
43 | WB_REASON_BACKGROUND, | |
44 | WB_REASON_TRY_TO_FREE_PAGES, | |
45 | WB_REASON_SYNC, | |
46 | WB_REASON_PERIODIC, | |
47 | WB_REASON_LAPTOP_TIMER, | |
48 | WB_REASON_FREE_MORE_MEM, | |
49 | WB_REASON_FS_FREE_SPACE, | |
fc6df808 WL |
50 | /* |
51 | * There is no bdi forker thread any more and works are done | |
52 | * by emergency worker, however, this is TPs userland visible | |
53 | * and we'll be exposing exactly the same information, | |
54 | * so it has a mismatch name. | |
55 | */ | |
0e175a18 CW |
56 | WB_REASON_FORKER_THREAD, |
57 | ||
58 | WB_REASON_MAX, | |
59 | }; | |
0e175a18 | 60 | |
1da177e4 LT |
61 | /* |
62 | * A control structure which tells the writeback code what to do. These are | |
63 | * always on the stack, and hence need no locking. They are always initialised | |
64 | * in a manner such that unspecified fields are set to zero. | |
65 | */ | |
66 | struct writeback_control { | |
1da177e4 LT |
67 | long nr_to_write; /* Write this many pages, and decrement |
68 | this for each page written */ | |
69 | long pages_skipped; /* Pages which were not written */ | |
70 | ||
71 | /* | |
95468fd4 | 72 | * For a_ops->writepages(): if start or end are non-zero then this is |
1da177e4 LT |
73 | * a hint that the filesystem need only write out the pages inside that |
74 | * byterange. The byte at `end' is included in the writeout request. | |
75 | */ | |
111ebb6e OH |
76 | loff_t range_start; |
77 | loff_t range_end; | |
1da177e4 | 78 | |
4cd9069a RK |
79 | enum writeback_sync_modes sync_mode; |
80 | ||
22905f77 | 81 | unsigned for_kupdate:1; /* A kupdate writeback */ |
b17621fe | 82 | unsigned for_background:1; /* A background writeback */ |
6e6938b6 | 83 | unsigned tagged_writepages:1; /* tag-and-write to avoid livelock */ |
22905f77 | 84 | unsigned for_reclaim:1; /* Invoked from the page allocator */ |
111ebb6e | 85 | unsigned range_cyclic:1; /* range_start is cyclic */ |
7747bd4b | 86 | unsigned for_sync:1; /* sync(2) WB_SYNC_ALL writeback */ |
1da177e4 LT |
87 | }; |
88 | ||
1da177e4 LT |
89 | /* |
90 | * fs/fs-writeback.c | |
91 | */ | |
03ba3782 | 92 | struct bdi_writeback; |
1da177e4 | 93 | int inode_wait(void *); |
0e175a18 CW |
94 | void writeback_inodes_sb(struct super_block *, enum wb_reason reason); |
95 | void writeback_inodes_sb_nr(struct super_block *, unsigned long nr, | |
96 | enum wb_reason reason); | |
10ee27a0 MX |
97 | int try_to_writeback_inodes_sb(struct super_block *, enum wb_reason reason); |
98 | int try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr, | |
99 | enum wb_reason reason); | |
0dc83bd3 | 100 | void sync_inodes_sb(struct super_block *); |
0e175a18 | 101 | void wakeup_flusher_threads(long nr_pages, enum wb_reason reason); |
169ebd90 | 102 | void inode_wait_for_writeback(struct inode *inode); |
1da177e4 LT |
103 | |
104 | /* writeback.h requires fs.h; it, too, is not included from here. */ | |
105 | static inline void wait_on_inode(struct inode *inode) | |
106 | { | |
107 | might_sleep(); | |
eaff8079 | 108 | wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE); |
1da177e4 | 109 | } |
1c0eeaf5 | 110 | |
1da177e4 LT |
111 | /* |
112 | * mm/page-writeback.c | |
113 | */ | |
c2c4986e | 114 | #ifdef CONFIG_BLOCK |
31373d09 | 115 | void laptop_io_completion(struct backing_dev_info *info); |
1da177e4 | 116 | void laptop_sync_completion(void); |
31373d09 MG |
117 | void laptop_mode_sync(struct work_struct *work); |
118 | void laptop_mode_timer_fn(unsigned long data); | |
c2c4986e JA |
119 | #else |
120 | static inline void laptop_sync_completion(void) { } | |
121 | #endif | |
232ea4d6 | 122 | void throttle_vm_writeout(gfp_t gfp_mask); |
a756cf59 | 123 | bool zone_dirty_ok(struct zone *zone); |
1da177e4 | 124 | |
c42843f2 WF |
125 | extern unsigned long global_dirty_limit; |
126 | ||
1da177e4 LT |
127 | /* These are exported to sysctl. */ |
128 | extern int dirty_background_ratio; | |
2da02997 | 129 | extern unsigned long dirty_background_bytes; |
1da177e4 | 130 | extern int vm_dirty_ratio; |
2da02997 | 131 | extern unsigned long vm_dirty_bytes; |
704503d8 AD |
132 | extern unsigned int dirty_writeback_interval; |
133 | extern unsigned int dirty_expire_interval; | |
195cf453 | 134 | extern int vm_highmem_is_dirtyable; |
1da177e4 LT |
135 | extern int block_dump; |
136 | extern int laptop_mode; | |
137 | ||
2da02997 | 138 | extern int dirty_background_ratio_handler(struct ctl_table *table, int write, |
8d65af78 | 139 | void __user *buffer, size_t *lenp, |
2da02997 DR |
140 | loff_t *ppos); |
141 | extern int dirty_background_bytes_handler(struct ctl_table *table, int write, | |
8d65af78 | 142 | void __user *buffer, size_t *lenp, |
2da02997 | 143 | loff_t *ppos); |
04fbfdc1 | 144 | extern int dirty_ratio_handler(struct ctl_table *table, int write, |
8d65af78 | 145 | void __user *buffer, size_t *lenp, |
04fbfdc1 | 146 | loff_t *ppos); |
2da02997 | 147 | extern int dirty_bytes_handler(struct ctl_table *table, int write, |
8d65af78 | 148 | void __user *buffer, size_t *lenp, |
2da02997 | 149 | loff_t *ppos); |
04fbfdc1 | 150 | |
1da177e4 | 151 | struct ctl_table; |
8d65af78 | 152 | int dirty_writeback_centisecs_handler(struct ctl_table *, int, |
1da177e4 LT |
153 | void __user *, size_t *, loff_t *); |
154 | ||
16c4042f WF |
155 | void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); |
156 | unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, | |
157 | unsigned long dirty); | |
cf0ca9fe | 158 | |
e98be2d5 | 159 | void __bdi_update_bandwidth(struct backing_dev_info *bdi, |
c42843f2 | 160 | unsigned long thresh, |
af6a3113 | 161 | unsigned long bg_thresh, |
c42843f2 WF |
162 | unsigned long dirty, |
163 | unsigned long bdi_thresh, | |
164 | unsigned long bdi_dirty, | |
e98be2d5 WF |
165 | unsigned long start_time); |
166 | ||
1da177e4 | 167 | void page_writeback_init(void); |
d0e1d66b | 168 | void balance_dirty_pages_ratelimited(struct address_space *mapping); |
fa5a734e | 169 | |
0ea97180 MS |
170 | typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, |
171 | void *data); | |
172 | ||
0ea97180 MS |
173 | int generic_writepages(struct address_space *mapping, |
174 | struct writeback_control *wbc); | |
5b41d924 ES |
175 | void tag_pages_for_writeback(struct address_space *mapping, |
176 | pgoff_t start, pgoff_t end); | |
0ea97180 MS |
177 | int write_cache_pages(struct address_space *mapping, |
178 | struct writeback_control *wbc, writepage_t writepage, | |
179 | void *data); | |
1da177e4 | 180 | int do_writepages(struct address_space *mapping, struct writeback_control *wbc); |
ed6d7c8e | 181 | void set_page_dirty_balance(struct page *page); |
2d1d43f6 | 182 | void writeback_set_ratelimit(void); |
92c09c04 NK |
183 | void tag_pages_for_writeback(struct address_space *mapping, |
184 | pgoff_t start, pgoff_t end); | |
1da177e4 | 185 | |
2f800fbd WF |
186 | void account_page_redirty(struct page *page); |
187 | ||
1da177e4 | 188 | #endif /* WRITEBACK_H */ |