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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * include/linux/writeback.h. | |
3 | */ | |
4 | #ifndef WRITEBACK_H | |
5 | #define WRITEBACK_H | |
6 | ||
7 | struct backing_dev_info; | |
8 | ||
9 | extern spinlock_t inode_lock; | |
10 | extern struct list_head inode_in_use; | |
11 | extern struct list_head inode_unused; | |
12 | ||
13 | /* | |
14 | * Yes, writeback.h requires sched.h | |
15 | * No, sched.h is not included from here. | |
16 | */ | |
22e2c507 | 17 | static inline int task_is_pdflush(struct task_struct *task) |
1da177e4 | 18 | { |
22e2c507 | 19 | return task->flags & PF_FLUSHER; |
1da177e4 LT |
20 | } |
21 | ||
22e2c507 JA |
22 | #define current_is_pdflush() task_is_pdflush(current) |
23 | ||
1da177e4 LT |
24 | /* |
25 | * fs/fs-writeback.c | |
26 | */ | |
27 | enum writeback_sync_modes { | |
28 | WB_SYNC_NONE, /* Don't wait on anything */ | |
29 | WB_SYNC_ALL, /* Wait on every mapping */ | |
30 | WB_SYNC_HOLD, /* Hold the inode on sb_dirty for sys_sync() */ | |
31 | }; | |
32 | ||
33 | /* | |
34 | * A control structure which tells the writeback code what to do. These are | |
35 | * always on the stack, and hence need no locking. They are always initialised | |
36 | * in a manner such that unspecified fields are set to zero. | |
37 | */ | |
38 | struct writeback_control { | |
39 | struct backing_dev_info *bdi; /* If !NULL, only write back this | |
40 | queue */ | |
41 | enum writeback_sync_modes sync_mode; | |
42 | unsigned long *older_than_this; /* If !NULL, only write back inodes | |
43 | older than this */ | |
44 | long nr_to_write; /* Write this many pages, and decrement | |
45 | this for each page written */ | |
46 | long pages_skipped; /* Pages which were not written */ | |
47 | ||
48 | /* | |
49 | * For a_ops->writepages(): is start or end are non-zero then this is | |
50 | * a hint that the filesystem need only write out the pages inside that | |
51 | * byterange. The byte at `end' is included in the writeout request. | |
52 | */ | |
53 | loff_t start; | |
54 | loff_t end; | |
55 | ||
56 | unsigned nonblocking:1; /* Don't get stuck on request queues */ | |
57 | unsigned encountered_congestion:1; /* An output: a queue is full */ | |
58 | unsigned for_kupdate:1; /* A kupdate writeback */ | |
59 | unsigned for_reclaim:1; /* Invoked from the page allocator */ | |
60 | }; | |
61 | ||
62 | /* | |
63 | * ->writepage() return values (make these much larger than a pagesize, in | |
64 | * case some fs is returning number-of-bytes-written from writepage) | |
65 | */ | |
66 | #define WRITEPAGE_ACTIVATE 0x80000 /* IO was not started: activate page */ | |
67 | ||
68 | /* | |
69 | * fs/fs-writeback.c | |
70 | */ | |
71 | void writeback_inodes(struct writeback_control *wbc); | |
72 | void wake_up_inode(struct inode *inode); | |
73 | int inode_wait(void *); | |
74 | void sync_inodes_sb(struct super_block *, int wait); | |
75 | void sync_inodes(int wait); | |
76 | ||
77 | /* writeback.h requires fs.h; it, too, is not included from here. */ | |
78 | static inline void wait_on_inode(struct inode *inode) | |
79 | { | |
80 | might_sleep(); | |
81 | wait_on_bit(&inode->i_state, __I_LOCK, inode_wait, | |
82 | TASK_UNINTERRUPTIBLE); | |
83 | } | |
84 | ||
85 | /* | |
86 | * mm/page-writeback.c | |
87 | */ | |
687a21ce | 88 | int wakeup_pdflush(long nr_pages); |
1da177e4 LT |
89 | void laptop_io_completion(void); |
90 | void laptop_sync_completion(void); | |
91 | void throttle_vm_writeout(void); | |
92 | ||
93 | /* These are exported to sysctl. */ | |
94 | extern int dirty_background_ratio; | |
95 | extern int vm_dirty_ratio; | |
96 | extern int dirty_writeback_centisecs; | |
97 | extern int dirty_expire_centisecs; | |
98 | extern int block_dump; | |
99 | extern int laptop_mode; | |
100 | ||
101 | struct ctl_table; | |
102 | struct file; | |
103 | int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *, | |
104 | void __user *, size_t *, loff_t *); | |
105 | ||
106 | void page_writeback_init(void); | |
107 | void balance_dirty_pages_ratelimited(struct address_space *mapping); | |
108 | int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0); | |
109 | int do_writepages(struct address_space *mapping, struct writeback_control *wbc); | |
110 | int sync_page_range(struct inode *inode, struct address_space *mapping, | |
111 | loff_t pos, size_t count); | |
112 | int sync_page_range_nolock(struct inode *inode, struct address_space | |
113 | *mapping, loff_t pos, size_t count); | |
114 | ||
115 | /* pdflush.c */ | |
116 | extern int nr_pdflush_threads; /* Global so it can be exported to sysctl | |
117 | read-only. */ | |
118 | ||
119 | ||
120 | #endif /* WRITEBACK_H */ |