writeback: split writeback_inodes_wb
[linux-2.6/next.git] / include / linux / writeback.h
blobc24eca71e80c8a1908a44cf94e11ed487b50b875
1 /*
2 * include/linux/writeback.h
3 */
4 #ifndef WRITEBACK_H
5 #define WRITEBACK_H
7 #include <linux/sched.h>
8 #include <linux/fs.h>
10 struct backing_dev_info;
12 extern spinlock_t inode_lock;
13 extern struct list_head inode_in_use;
14 extern struct list_head inode_unused;
17 * fs/fs-writeback.c
19 enum writeback_sync_modes {
20 WB_SYNC_NONE, /* Don't wait on anything */
21 WB_SYNC_ALL, /* Wait on every mapping */
25 * A control structure which tells the writeback code what to do. These are
26 * always on the stack, and hence need no locking. They are always initialised
27 * in a manner such that unspecified fields are set to zero.
29 struct writeback_control {
30 enum writeback_sync_modes sync_mode;
31 unsigned long *older_than_this; /* If !NULL, only write back inodes
32 older than this */
33 unsigned long wb_start; /* Time writeback_inodes_wb was
34 called. This is needed to avoid
35 extra jobs and livelock */
36 long nr_to_write; /* Write this many pages, and decrement
37 this for each page written */
38 long pages_skipped; /* Pages which were not written */
41 * For a_ops->writepages(): is start or end are non-zero then this is
42 * a hint that the filesystem need only write out the pages inside that
43 * byterange. The byte at `end' is included in the writeout request.
45 loff_t range_start;
46 loff_t range_end;
48 unsigned nonblocking:1; /* Don't get stuck on request queues */
49 unsigned encountered_congestion:1; /* An output: a queue is full */
50 unsigned for_kupdate:1; /* A kupdate writeback */
51 unsigned for_background:1; /* A background writeback */
52 unsigned for_reclaim:1; /* Invoked from the page allocator */
53 unsigned range_cyclic:1; /* range_start is cyclic */
54 unsigned more_io:1; /* more io to be dispatched */
58 * fs/fs-writeback.c
59 */
60 struct bdi_writeback;
61 int inode_wait(void *);
62 void writeback_inodes_sb(struct super_block *);
63 int writeback_inodes_sb_if_idle(struct super_block *);
64 void sync_inodes_sb(struct super_block *);
65 void writeback_inodes_wb(struct bdi_writeback *wb,
66 struct writeback_control *wbc);
67 long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
68 void wakeup_flusher_threads(long nr_pages);
70 /* writeback.h requires fs.h; it, too, is not included from here. */
71 static inline void wait_on_inode(struct inode *inode)
73 might_sleep();
74 wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
76 static inline void inode_sync_wait(struct inode *inode)
78 might_sleep();
79 wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
80 TASK_UNINTERRUPTIBLE);
85 * mm/page-writeback.c
87 #ifdef CONFIG_BLOCK
88 void laptop_io_completion(struct backing_dev_info *info);
89 void laptop_sync_completion(void);
90 void laptop_mode_sync(struct work_struct *work);
91 void laptop_mode_timer_fn(unsigned long data);
92 #else
93 static inline void laptop_sync_completion(void) { }
94 #endif
95 void throttle_vm_writeout(gfp_t gfp_mask);
97 /* These are exported to sysctl. */
98 extern int dirty_background_ratio;
99 extern unsigned long dirty_background_bytes;
100 extern int vm_dirty_ratio;
101 extern unsigned long vm_dirty_bytes;
102 extern unsigned int dirty_writeback_interval;
103 extern unsigned int dirty_expire_interval;
104 extern int vm_highmem_is_dirtyable;
105 extern int block_dump;
106 extern int laptop_mode;
108 extern unsigned long determine_dirtyable_memory(void);
110 extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
111 void __user *buffer, size_t *lenp,
112 loff_t *ppos);
113 extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
114 void __user *buffer, size_t *lenp,
115 loff_t *ppos);
116 extern int dirty_ratio_handler(struct ctl_table *table, int write,
117 void __user *buffer, size_t *lenp,
118 loff_t *ppos);
119 extern int dirty_bytes_handler(struct ctl_table *table, int write,
120 void __user *buffer, size_t *lenp,
121 loff_t *ppos);
123 struct ctl_table;
124 int dirty_writeback_centisecs_handler(struct ctl_table *, int,
125 void __user *, size_t *, loff_t *);
127 void get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
128 unsigned long *pbdi_dirty, struct backing_dev_info *bdi);
130 void page_writeback_init(void);
131 void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
132 unsigned long nr_pages_dirtied);
134 static inline void
135 balance_dirty_pages_ratelimited(struct address_space *mapping)
137 balance_dirty_pages_ratelimited_nr(mapping, 1);
140 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
141 void *data);
143 int generic_writepages(struct address_space *mapping,
144 struct writeback_control *wbc);
145 int write_cache_pages(struct address_space *mapping,
146 struct writeback_control *wbc, writepage_t writepage,
147 void *data);
148 int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
149 void set_page_dirty_balance(struct page *page, int page_mkwrite);
150 void writeback_set_ratelimit(void);
152 /* pdflush.c */
153 extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
154 read-only. */
157 #endif /* WRITEBACK_H */