2 * include/linux/writeback.h
7 #include <linux/sched.h>
10 struct backing_dev_info;
15 enum writeback_sync_modes {
16 WB_SYNC_NONE, /* Don't wait on anything */
17 WB_SYNC_ALL, /* Wait on every mapping */
21 * A control structure which tells the writeback code what to do. These are
22 * always on the stack, and hence need no locking. They are always initialised
23 * in a manner such that unspecified fields are set to zero.
25 struct writeback_control {
26 enum writeback_sync_modes sync_mode;
27 long nr_to_write; /* Write this many pages, and decrement
28 this for each page written */
29 long pages_skipped; /* Pages which were not written */
32 * For a_ops->writepages(): is start or end are non-zero then this is
33 * a hint that the filesystem need only write out the pages inside that
34 * byterange. The byte at `end' is included in the writeout request.
39 unsigned for_kupdate:1; /* A kupdate writeback */
40 unsigned for_background:1; /* A background writeback */
41 unsigned tagged_writepages:1; /* tag-and-write to avoid livelock */
42 unsigned for_reclaim:1; /* Invoked from the page allocator */
43 unsigned range_cyclic:1; /* range_start is cyclic */
50 int inode_wait(void *);
51 void writeback_inodes_sb(struct super_block *);
52 void writeback_inodes_sb_nr(struct super_block *, unsigned long nr);
53 int writeback_inodes_sb_if_idle(struct super_block *);
54 int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr);
55 void sync_inodes_sb(struct super_block *);
56 long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages);
57 long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
58 void wakeup_flusher_threads(long nr_pages);
60 /* writeback.h requires fs.h; it, too, is not included from here. */
61 static inline void wait_on_inode(struct inode *inode)
64 wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
66 static inline void inode_sync_wait(struct inode *inode)
69 wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
70 TASK_UNINTERRUPTIBLE);
78 void laptop_io_completion(struct backing_dev_info *info);
79 void laptop_sync_completion(void);
80 void laptop_mode_sync(struct work_struct *work);
81 void laptop_mode_timer_fn(unsigned long data);
83 static inline void laptop_sync_completion(void) { }
85 void throttle_vm_writeout(gfp_t gfp_mask);
87 /* These are exported to sysctl. */
88 extern int dirty_background_ratio;
89 extern unsigned long dirty_background_bytes;
90 extern int vm_dirty_ratio;
91 extern unsigned long vm_dirty_bytes;
92 extern unsigned int dirty_writeback_interval;
93 extern unsigned int dirty_expire_interval;
94 extern int vm_highmem_is_dirtyable;
95 extern int block_dump;
96 extern int laptop_mode;
98 extern unsigned long determine_dirtyable_memory(void);
100 extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
101 void __user *buffer, size_t *lenp,
103 extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
104 void __user *buffer, size_t *lenp,
106 extern int dirty_ratio_handler(struct ctl_table *table, int write,
107 void __user *buffer, size_t *lenp,
109 extern int dirty_bytes_handler(struct ctl_table *table, int write,
110 void __user *buffer, size_t *lenp,
114 int dirty_writeback_centisecs_handler(struct ctl_table *, int,
115 void __user *, size_t *, loff_t *);
117 void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
118 unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
119 unsigned long dirty);
121 void __bdi_update_bandwidth(struct backing_dev_info *bdi,
122 unsigned long start_time);
124 void page_writeback_init(void);
125 void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
126 unsigned long nr_pages_dirtied);
129 balance_dirty_pages_ratelimited(struct address_space *mapping)
131 balance_dirty_pages_ratelimited_nr(mapping, 1);
134 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
137 int generic_writepages(struct address_space *mapping,
138 struct writeback_control *wbc);
139 void tag_pages_for_writeback(struct address_space *mapping,
140 pgoff_t start, pgoff_t end);
141 int write_cache_pages(struct address_space *mapping,
142 struct writeback_control *wbc, writepage_t writepage,
144 int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
145 void set_page_dirty_balance(struct page *page, int page_mkwrite);
146 void writeback_set_ratelimit(void);
147 void tag_pages_for_writeback(struct address_space *mapping,
148 pgoff_t start, pgoff_t end);
151 extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
155 #endif /* WRITEBACK_H */