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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02002 * include/linux/writeback.h
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 */
4#ifndef WRITEBACK_H
5#define WRITEBACK_H
6
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +04007#include <linux/sched.h>
Jens Axboef5ff8422007-09-21 09:19:54 +02008#include <linux/fs.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +04009
Linus Torvalds1da177e2005-04-16 15:20:36 -070010struct backing_dev_info;
11
12extern spinlock_t inode_lock;
13extern struct list_head inode_in_use;
14extern struct list_head inode_unused;
15
16/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 * fs/fs-writeback.c
18 */
19enum writeback_sync_modes {
20 WB_SYNC_NONE, /* Don't wait on anything */
21 WB_SYNC_ALL, /* Wait on every mapping */
Linus Torvalds1da177e2005-04-16 15:20:36 -070022};
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 */
29struct writeback_control {
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 enum writeback_sync_modes sync_mode;
31 unsigned long *older_than_this; /* If !NULL, only write back inodes
32 older than this */
Edward Shishkinf11c9c52010-03-11 14:09:47 -080033 unsigned long wb_start; /* Time writeback_inodes_wb was
34 called. This is needed to avoid
35 extra jobs and livelock */
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 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 */
39
40 /*
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.
44 */
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -070045 loff_t range_start;
46 loff_t range_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Andrew Morton22905f72005-11-16 15:07:01 -080048 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 */
Wu Fengguangb17621f2009-12-03 13:54:25 +010051 unsigned for_background:1; /* A background writeback */
Andrew Morton22905f72005-11-16 15:07:01 -080052 unsigned for_reclaim:1; /* Invoked from the page allocator */
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -070053 unsigned range_cyclic:1; /* range_start is cyclic */
Fengguang Wu8bc3be22008-02-04 22:29:36 -080054 unsigned more_io:1; /* more io to be dispatched */
Linus Torvalds1da177e2005-04-16 15:20:36 -070055};
56
57/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 * fs/fs-writeback.c
59 */
Jens Axboe03ba3782009-09-09 09:08:54 +020060struct bdi_writeback;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061int inode_wait(void *);
Jens Axboeb6e51312009-09-16 15:13:54 +020062void writeback_inodes_sb(struct super_block *);
Eric Sandeen17bd55d2009-12-23 07:57:07 -050063int writeback_inodes_sb_if_idle(struct super_block *);
Jens Axboeb6e51312009-09-16 15:13:54 +020064void sync_inodes_sb(struct super_block *);
Christoph Hellwig9c3a8ee2010-06-10 12:07:27 +020065void writeback_inodes_wb(struct bdi_writeback *wb,
66 struct writeback_control *wbc);
Jens Axboe03ba3782009-09-09 09:08:54 +020067long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
68void wakeup_flusher_threads(long nr_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70/* writeback.h requires fs.h; it, too, is not included from here. */
71static inline void wait_on_inode(struct inode *inode)
72{
73 might_sleep();
Christoph Hellwigeaff8072009-12-17 14:25:01 +010074 wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075}
Joern Engel1c0eeaf2007-10-16 23:30:44 -070076static inline void inode_sync_wait(struct inode *inode)
77{
78 might_sleep();
79 wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
80 TASK_UNINTERRUPTIBLE);
81}
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84/*
85 * mm/page-writeback.c
86 */
Jens Axboec2c49862010-05-20 09:18:47 +020087#ifdef CONFIG_BLOCK
Matthew Garrett31373d02010-04-06 14:25:14 +020088void laptop_io_completion(struct backing_dev_info *info);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089void laptop_sync_completion(void);
Matthew Garrett31373d02010-04-06 14:25:14 +020090void laptop_mode_sync(struct work_struct *work);
91void laptop_mode_timer_fn(unsigned long data);
Jens Axboec2c49862010-05-20 09:18:47 +020092#else
93static inline void laptop_sync_completion(void) { }
94#endif
Andrew Morton232ea4d2007-02-28 20:13:21 -080095void throttle_vm_writeout(gfp_t gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97/* These are exported to sysctl. */
98extern int dirty_background_ratio;
David Rientjes2da02992009-01-06 14:39:31 -080099extern unsigned long dirty_background_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100extern int vm_dirty_ratio;
David Rientjes2da02992009-01-06 14:39:31 -0800101extern unsigned long vm_dirty_bytes;
Alexey Dobriyan704503d2009-03-31 15:23:18 -0700102extern unsigned int dirty_writeback_interval;
103extern unsigned int dirty_expire_interval;
Bron Gondwana195cf4532008-02-04 22:29:20 -0800104extern int vm_highmem_is_dirtyable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105extern int block_dump;
106extern int laptop_mode;
107
Steven Rostedt3eefae92008-05-12 21:21:04 +0200108extern unsigned long determine_dirtyable_memory(void);
109
David Rientjes2da02992009-01-06 14:39:31 -0800110extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700111 void __user *buffer, size_t *lenp,
David Rientjes2da02992009-01-06 14:39:31 -0800112 loff_t *ppos);
113extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700114 void __user *buffer, size_t *lenp,
David Rientjes2da02992009-01-06 14:39:31 -0800115 loff_t *ppos);
Peter Zijlstra04fbfdc2007-10-16 23:25:50 -0700116extern int dirty_ratio_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700117 void __user *buffer, size_t *lenp,
Peter Zijlstra04fbfdc2007-10-16 23:25:50 -0700118 loff_t *ppos);
David Rientjes2da02992009-01-06 14:39:31 -0800119extern int dirty_bytes_handler(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700120 void __user *buffer, size_t *lenp,
David Rientjes2da02992009-01-06 14:39:31 -0800121 loff_t *ppos);
Peter Zijlstra04fbfdc2007-10-16 23:25:50 -0700122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123struct ctl_table;
Alexey Dobriyan8d65af72009-09-23 15:57:19 -0700124int dirty_writeback_centisecs_handler(struct ctl_table *, int,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 void __user *, size_t *, loff_t *);
126
Wu Fengguang16c40422010-08-11 14:17:39 -0700127void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
128unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
129 unsigned long dirty);
Peter Zijlstracf0ca9f2008-04-30 00:54:32 -0700130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131void page_writeback_init(void);
Andrew Mortonfa5a7342006-03-24 03:18:10 -0800132void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
133 unsigned long nr_pages_dirtied);
134
135static inline void
136balance_dirty_pages_ratelimited(struct address_space *mapping)
137{
138 balance_dirty_pages_ratelimited_nr(mapping, 1);
139}
140
Miklos Szeredi0ea97182007-05-10 22:22:51 -0700141typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
142 void *data);
143
Miklos Szeredi0ea97182007-05-10 22:22:51 -0700144int generic_writepages(struct address_space *mapping,
145 struct writeback_control *wbc);
146int write_cache_pages(struct address_space *mapping,
147 struct writeback_control *wbc, writepage_t writepage,
148 void *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
Peter Zijlstraa200ee12007-10-08 18:54:37 +0200150void set_page_dirty_balance(struct page *page, int page_mkwrite);
Chandra Seetharaman2d1d43f2006-09-29 02:01:25 -0700151void writeback_set_ratelimit(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153/* pdflush.c */
154extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
155 read-only. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157
158#endif /* WRITEBACK_H */