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Commit | Line | Data |
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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> |
f5ff8422 | 8 | #include <linux/fs.h> |
e8edc6e0 | 9 | |
1da177e4 LT |
10 | struct backing_dev_info; |
11 | ||
12 | extern spinlock_t inode_lock; | |
13 | extern struct list_head inode_in_use; | |
14 | extern struct list_head inode_unused; | |
15 | ||
16 | /* | |
17 | * Yes, writeback.h requires sched.h | |
18 | * No, sched.h is not included from here. | |
19 | */ | |
22e2c507 | 20 | static inline int task_is_pdflush(struct task_struct *task) |
1da177e4 | 21 | { |
22e2c507 | 22 | return task->flags & PF_FLUSHER; |
1da177e4 LT |
23 | } |
24 | ||
22e2c507 JA |
25 | #define current_is_pdflush() task_is_pdflush(current) |
26 | ||
1da177e4 LT |
27 | /* |
28 | * fs/fs-writeback.c | |
29 | */ | |
30 | enum writeback_sync_modes { | |
31 | WB_SYNC_NONE, /* Don't wait on anything */ | |
32 | WB_SYNC_ALL, /* Wait on every mapping */ | |
1da177e4 LT |
33 | }; |
34 | ||
35 | /* | |
36 | * A control structure which tells the writeback code what to do. These are | |
37 | * always on the stack, and hence need no locking. They are always initialised | |
38 | * in a manner such that unspecified fields are set to zero. | |
39 | */ | |
40 | struct writeback_control { | |
41 | struct backing_dev_info *bdi; /* If !NULL, only write back this | |
42 | queue */ | |
43 | enum writeback_sync_modes sync_mode; | |
44 | unsigned long *older_than_this; /* If !NULL, only write back inodes | |
45 | older than this */ | |
46 | long nr_to_write; /* Write this many pages, and decrement | |
47 | this for each page written */ | |
48 | long pages_skipped; /* Pages which were not written */ | |
49 | ||
50 | /* | |
51 | * For a_ops->writepages(): is start or end are non-zero then this is | |
52 | * a hint that the filesystem need only write out the pages inside that | |
53 | * byterange. The byte at `end' is included in the writeout request. | |
54 | */ | |
111ebb6e OH |
55 | loff_t range_start; |
56 | loff_t range_end; | |
1da177e4 | 57 | |
22905f77 AM |
58 | unsigned nonblocking:1; /* Don't get stuck on request queues */ |
59 | unsigned encountered_congestion:1; /* An output: a queue is full */ | |
60 | unsigned for_kupdate:1; /* A kupdate writeback */ | |
61 | unsigned for_reclaim:1; /* Invoked from the page allocator */ | |
62 | unsigned for_writepages:1; /* This is a writepages() call */ | |
111ebb6e | 63 | unsigned range_cyclic:1; /* range_start is cyclic */ |
8bc3be27 | 64 | unsigned more_io:1; /* more io to be dispatched */ |
17bc6c30 AK |
65 | /* |
66 | * write_cache_pages() won't update wbc->nr_to_write and | |
67 | * mapping->writeback_index if no_nrwrite_index_update | |
68 | * is set. write_cache_pages() may write more than we | |
69 | * requested and we want to make sure nr_to_write and | |
70 | * writeback_index are updated in a consistent manner | |
71 | * so we use a single control to update them | |
72 | */ | |
73 | unsigned no_nrwrite_index_update:1; | |
1da177e4 LT |
74 | }; |
75 | ||
1da177e4 LT |
76 | /* |
77 | * fs/fs-writeback.c | |
78 | */ | |
79 | void writeback_inodes(struct writeback_control *wbc); | |
1da177e4 LT |
80 | int inode_wait(void *); |
81 | void sync_inodes_sb(struct super_block *, int wait); | |
82 | void sync_inodes(int wait); | |
83 | ||
84 | /* writeback.h requires fs.h; it, too, is not included from here. */ | |
85 | static inline void wait_on_inode(struct inode *inode) | |
86 | { | |
87 | might_sleep(); | |
88 | wait_on_bit(&inode->i_state, __I_LOCK, inode_wait, | |
89 | TASK_UNINTERRUPTIBLE); | |
90 | } | |
1c0eeaf5 JE |
91 | static inline void inode_sync_wait(struct inode *inode) |
92 | { | |
93 | might_sleep(); | |
94 | wait_on_bit(&inode->i_state, __I_SYNC, inode_wait, | |
95 | TASK_UNINTERRUPTIBLE); | |
96 | } | |
97 | ||
1da177e4 LT |
98 | |
99 | /* | |
100 | * mm/page-writeback.c | |
101 | */ | |
687a21ce | 102 | int wakeup_pdflush(long nr_pages); |
1da177e4 LT |
103 | void laptop_io_completion(void); |
104 | void laptop_sync_completion(void); | |
232ea4d6 | 105 | void throttle_vm_writeout(gfp_t gfp_mask); |
1da177e4 LT |
106 | |
107 | /* These are exported to sysctl. */ | |
108 | extern int dirty_background_ratio; | |
2da02997 | 109 | extern unsigned long dirty_background_bytes; |
1da177e4 | 110 | extern int vm_dirty_ratio; |
2da02997 | 111 | extern unsigned long vm_dirty_bytes; |
f6ef9438 BS |
112 | extern int dirty_writeback_interval; |
113 | extern int dirty_expire_interval; | |
195cf453 | 114 | extern int vm_highmem_is_dirtyable; |
1da177e4 LT |
115 | extern int block_dump; |
116 | extern int laptop_mode; | |
117 | ||
3eefae99 SR |
118 | extern unsigned long determine_dirtyable_memory(void); |
119 | ||
2da02997 DR |
120 | extern int dirty_background_ratio_handler(struct ctl_table *table, int write, |
121 | struct file *filp, void __user *buffer, size_t *lenp, | |
122 | loff_t *ppos); | |
123 | extern int dirty_background_bytes_handler(struct ctl_table *table, int write, | |
124 | struct file *filp, void __user *buffer, size_t *lenp, | |
125 | loff_t *ppos); | |
04fbfdc1 PZ |
126 | extern int dirty_ratio_handler(struct ctl_table *table, int write, |
127 | struct file *filp, void __user *buffer, size_t *lenp, | |
128 | loff_t *ppos); | |
2da02997 DR |
129 | extern int dirty_bytes_handler(struct ctl_table *table, int write, |
130 | struct file *filp, void __user *buffer, size_t *lenp, | |
131 | loff_t *ppos); | |
04fbfdc1 | 132 | |
1da177e4 LT |
133 | struct ctl_table; |
134 | struct file; | |
135 | int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *, | |
136 | void __user *, size_t *, loff_t *); | |
137 | ||
364aeb28 DR |
138 | void get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty, |
139 | unsigned long *pbdi_dirty, struct backing_dev_info *bdi); | |
cf0ca9fe | 140 | |
1da177e4 | 141 | void page_writeback_init(void); |
fa5a734e AM |
142 | void balance_dirty_pages_ratelimited_nr(struct address_space *mapping, |
143 | unsigned long nr_pages_dirtied); | |
144 | ||
145 | static inline void | |
146 | balance_dirty_pages_ratelimited(struct address_space *mapping) | |
147 | { | |
148 | balance_dirty_pages_ratelimited_nr(mapping, 1); | |
149 | } | |
150 | ||
0ea97180 MS |
151 | typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, |
152 | void *data); | |
153 | ||
1da177e4 | 154 | int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0); |
0ea97180 MS |
155 | int generic_writepages(struct address_space *mapping, |
156 | struct writeback_control *wbc); | |
157 | int write_cache_pages(struct address_space *mapping, | |
158 | struct writeback_control *wbc, writepage_t writepage, | |
159 | void *data); | |
1da177e4 LT |
160 | int do_writepages(struct address_space *mapping, struct writeback_control *wbc); |
161 | int sync_page_range(struct inode *inode, struct address_space *mapping, | |
268fc16e OH |
162 | loff_t pos, loff_t count); |
163 | int sync_page_range_nolock(struct inode *inode, struct address_space *mapping, | |
164 | loff_t pos, loff_t count); | |
a200ee18 | 165 | void set_page_dirty_balance(struct page *page, int page_mkwrite); |
2d1d43f6 | 166 | void writeback_set_ratelimit(void); |
1da177e4 LT |
167 | |
168 | /* pdflush.c */ | |
169 | extern int nr_pdflush_threads; /* Global so it can be exported to sysctl | |
170 | read-only. */ | |
171 | ||
172 | ||
173 | #endif /* WRITEBACK_H */ |