sysctl: remove "struct file *" argument of ->proc_handler
[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 extern spinlock_t inode_lock;
13 extern struct list_head inode_in_use;
14 extern struct list_head inode_unused;
15
16 /*
17  * fs/fs-writeback.c
18  */
19 enum writeback_sync_modes {
20         WB_SYNC_NONE,   /* Don't wait on anything */
21         WB_SYNC_ALL,    /* Wait on every mapping */
22 };
23
24 /*
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.
28  */
29 struct writeback_control {
30         struct backing_dev_info *bdi;   /* If !NULL, only write back this
31                                            queue */
32         struct super_block *sb;         /* if !NULL, only write inodes from
33                                            this super_block */
34         enum writeback_sync_modes sync_mode;
35         unsigned long *older_than_this; /* If !NULL, only write back inodes
36                                            older than this */
37         long nr_to_write;               /* Write this many pages, and decrement
38                                            this for each page written */
39         long pages_skipped;             /* Pages which were not written */
40
41         /*
42          * For a_ops->writepages(): is start or end are non-zero then this is
43          * a hint that the filesystem need only write out the pages inside that
44          * byterange.  The byte at `end' is included in the writeout request.
45          */
46         loff_t range_start;
47         loff_t range_end;
48
49         unsigned nonblocking:1;         /* Don't get stuck on request queues */
50         unsigned encountered_congestion:1; /* An output: a queue is full */
51         unsigned for_kupdate:1;         /* A kupdate 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 */
55         /*
56          * write_cache_pages() won't update wbc->nr_to_write and
57          * mapping->writeback_index if no_nrwrite_index_update
58          * is set.  write_cache_pages() may write more than we
59          * requested and we want to make sure nr_to_write and
60          * writeback_index are updated in a consistent manner
61          * so we use a single control to update them
62          */
63         unsigned no_nrwrite_index_update:1;
64 };
65
66 /*
67  * fs/fs-writeback.c
68  */     
69 struct bdi_writeback;
70 int inode_wait(void *);
71 void writeback_inodes_sb(struct super_block *);
72 void sync_inodes_sb(struct super_block *);
73 void writeback_inodes_wbc(struct writeback_control *wbc);
74 long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
75 void wakeup_flusher_threads(long nr_pages);
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 static inline void inode_sync_wait(struct inode *inode)
85 {
86         might_sleep();
87         wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
88                                                         TASK_UNINTERRUPTIBLE);
89 }
90
91
92 /*
93  * mm/page-writeback.c
94  */
95 void laptop_io_completion(void);
96 void laptop_sync_completion(void);
97 void throttle_vm_writeout(gfp_t gfp_mask);
98
99 /* These are exported to sysctl. */
100 extern int dirty_background_ratio;
101 extern unsigned long dirty_background_bytes;
102 extern int vm_dirty_ratio;
103 extern unsigned long vm_dirty_bytes;
104 extern unsigned int dirty_writeback_interval;
105 extern unsigned int dirty_expire_interval;
106 extern int vm_highmem_is_dirtyable;
107 extern int block_dump;
108 extern int laptop_mode;
109
110 extern unsigned long determine_dirtyable_memory(void);
111
112 extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
113                 void __user *buffer, size_t *lenp,
114                 loff_t *ppos);
115 extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
116                 void __user *buffer, size_t *lenp,
117                 loff_t *ppos);
118 extern int dirty_ratio_handler(struct ctl_table *table, int write,
119                 void __user *buffer, size_t *lenp,
120                 loff_t *ppos);
121 extern int dirty_bytes_handler(struct ctl_table *table, int write,
122                 void __user *buffer, size_t *lenp,
123                 loff_t *ppos);
124
125 struct ctl_table;
126 int dirty_writeback_centisecs_handler(struct ctl_table *, int,
127                                       void __user *, size_t *, loff_t *);
128
129 void get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
130                       unsigned long *pbdi_dirty, struct backing_dev_info *bdi);
131
132 void page_writeback_init(void);
133 void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
134                                         unsigned long nr_pages_dirtied);
135
136 static inline void
137 balance_dirty_pages_ratelimited(struct address_space *mapping)
138 {
139         balance_dirty_pages_ratelimited_nr(mapping, 1);
140 }
141
142 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
143                                 void *data);
144
145 int generic_writepages(struct address_space *mapping,
146                        struct writeback_control *wbc);
147 int write_cache_pages(struct address_space *mapping,
148                       struct writeback_control *wbc, writepage_t writepage,
149                       void *data);
150 int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
151 void set_page_dirty_balance(struct page *page, int page_mkwrite);
152 void writeback_set_ratelimit(void);
153
154 /* pdflush.c */
155 extern int nr_pdflush_threads;  /* Global so it can be exported to sysctl
156                                    read-only. */
157
158
159 #endif          /* WRITEBACK_H */