writeback: remove writeback_control.more_io
[linux-2.6.git] / include / linux / writeback.h
1 /*
2  * include/linux/writeback.h
3  */
4 #ifndef WRITEBACK_H
5 #define WRITEBACK_H
6
7 #include <linux/sched.h>
8 #include <linux/fs.h>
9
10 struct backing_dev_info;
11
12 /*
13  * fs/fs-writeback.c
14  */
15 enum writeback_sync_modes {
16         WB_SYNC_NONE,   /* Don't wait on anything */
17         WB_SYNC_ALL,    /* Wait on every mapping */
18 };
19
20 /*
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.
24  */
25 struct writeback_control {
26         enum writeback_sync_modes sync_mode;
27         unsigned long *older_than_this; /* If !NULL, only write back inodes
28                                            older than this */
29         long nr_to_write;               /* Write this many pages, and decrement
30                                            this for each page written */
31         long pages_skipped;             /* Pages which were not written */
32         long inodes_written;            /* # of inodes written (at least) */
33
34         /*
35          * For a_ops->writepages(): is start or end are non-zero then this is
36          * a hint that the filesystem need only write out the pages inside that
37          * byterange.  The byte at `end' is included in the writeout request.
38          */
39         loff_t range_start;
40         loff_t range_end;
41
42         unsigned nonblocking:1;         /* Don't get stuck on request queues */
43         unsigned encountered_congestion:1; /* An output: a queue is full */
44         unsigned for_kupdate:1;         /* A kupdate writeback */
45         unsigned for_background:1;      /* A background writeback */
46         unsigned tagged_writepages:1;   /* tag-and-write to avoid livelock */
47         unsigned for_reclaim:1;         /* Invoked from the page allocator */
48         unsigned range_cyclic:1;        /* range_start is cyclic */
49 };
50
51 /*
52  * fs/fs-writeback.c
53  */     
54 struct bdi_writeback;
55 int inode_wait(void *);
56 void writeback_inodes_sb(struct super_block *);
57 void writeback_inodes_sb_nr(struct super_block *, unsigned long nr);
58 int writeback_inodes_sb_if_idle(struct super_block *);
59 int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr);
60 void sync_inodes_sb(struct super_block *);
61 void writeback_inodes_wb(struct bdi_writeback *wb,
62                 struct writeback_control *wbc);
63 long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
64 void wakeup_flusher_threads(long nr_pages);
65
66 /* writeback.h requires fs.h; it, too, is not included from here. */
67 static inline void wait_on_inode(struct inode *inode)
68 {
69         might_sleep();
70         wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
71 }
72 static inline void inode_sync_wait(struct inode *inode)
73 {
74         might_sleep();
75         wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
76                                                         TASK_UNINTERRUPTIBLE);
77 }
78
79
80 /*
81  * mm/page-writeback.c
82  */
83 #ifdef CONFIG_BLOCK
84 void laptop_io_completion(struct backing_dev_info *info);
85 void laptop_sync_completion(void);
86 void laptop_mode_sync(struct work_struct *work);
87 void laptop_mode_timer_fn(unsigned long data);
88 #else
89 static inline void laptop_sync_completion(void) { }
90 #endif
91 void throttle_vm_writeout(gfp_t gfp_mask);
92
93 /* These are exported to sysctl. */
94 extern int dirty_background_ratio;
95 extern unsigned long dirty_background_bytes;
96 extern int vm_dirty_ratio;
97 extern unsigned long vm_dirty_bytes;
98 extern unsigned int dirty_writeback_interval;
99 extern unsigned int dirty_expire_interval;
100 extern int vm_highmem_is_dirtyable;
101 extern int block_dump;
102 extern int laptop_mode;
103
104 extern unsigned long determine_dirtyable_memory(void);
105
106 extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
107                 void __user *buffer, size_t *lenp,
108                 loff_t *ppos);
109 extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
110                 void __user *buffer, size_t *lenp,
111                 loff_t *ppos);
112 extern int dirty_ratio_handler(struct ctl_table *table, int write,
113                 void __user *buffer, size_t *lenp,
114                 loff_t *ppos);
115 extern int dirty_bytes_handler(struct ctl_table *table, int write,
116                 void __user *buffer, size_t *lenp,
117                 loff_t *ppos);
118
119 struct ctl_table;
120 int dirty_writeback_centisecs_handler(struct ctl_table *, int,
121                                       void __user *, size_t *, loff_t *);
122
123 void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
124 unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
125                                unsigned long dirty);
126
127 void page_writeback_init(void);
128 void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
129                                         unsigned long nr_pages_dirtied);
130
131 static inline void
132 balance_dirty_pages_ratelimited(struct address_space *mapping)
133 {
134         balance_dirty_pages_ratelimited_nr(mapping, 1);
135 }
136
137 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
138                                 void *data);
139
140 int generic_writepages(struct address_space *mapping,
141                        struct writeback_control *wbc);
142 void tag_pages_for_writeback(struct address_space *mapping,
143                              pgoff_t start, pgoff_t end);
144 int write_cache_pages(struct address_space *mapping,
145                       struct writeback_control *wbc, writepage_t writepage,
146                       void *data);
147 int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
148 void set_page_dirty_balance(struct page *page, int page_mkwrite);
149 void writeback_set_ratelimit(void);
150 void tag_pages_for_writeback(struct address_space *mapping,
151                              pgoff_t start, pgoff_t end);
152
153 /* pdflush.c */
154 extern int nr_pdflush_threads;  /* Global so it can be exported to sysctl
155                                    read-only. */
156
157
158 #endif          /* WRITEBACK_H */