2 * include/linux/writeback.h
7 #include <linux/sched.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 * Yes, writeback.h requires sched.h
18 * No, sched.h is not included from here.
20 static inline int task_is_pdflush(struct task_struct
*task
)
22 return task
->flags
& PF_FLUSHER
;
25 #define current_is_pdflush() task_is_pdflush(current)
30 enum writeback_sync_modes
{
31 WB_SYNC_NONE
, /* Don't wait on anything */
32 WB_SYNC_ALL
, /* Wait on every mapping */
33 WB_SYNC_HOLD
, /* Hold the inode on sb_dirty for sys_sync() */
37 * A control structure which tells the writeback code what to do. These are
38 * always on the stack, and hence need no locking. They are always initialised
39 * in a manner such that unspecified fields are set to zero.
41 struct writeback_control
{
42 struct backing_dev_info
*bdi
; /* If !NULL, only write back this
44 enum writeback_sync_modes sync_mode
;
45 unsigned long *older_than_this
; /* If !NULL, only write back inodes
47 long nr_to_write
; /* Write this many pages, and decrement
48 this for each page written */
49 long pages_skipped
; /* Pages which were not written */
52 * For a_ops->writepages(): is start or end are non-zero then this is
53 * a hint that the filesystem need only write out the pages inside that
54 * byterange. The byte at `end' is included in the writeout request.
59 unsigned nonblocking
:1; /* Don't get stuck on request queues */
60 unsigned encountered_congestion
:1; /* An output: a queue is full */
61 unsigned for_kupdate
:1; /* A kupdate writeback */
62 unsigned for_reclaim
:1; /* Invoked from the page allocator */
63 unsigned for_writepages
:1; /* This is a writepages() call */
64 unsigned range_cyclic
:1; /* range_start is cyclic */
65 unsigned more_io
:1; /* more io to be dispatched */
71 void writeback_inodes(struct writeback_control
*wbc
);
72 int inode_wait(void *);
73 void sync_inodes_sb(struct super_block
*, int wait
);
74 void sync_inodes(int wait
);
76 /* writeback.h requires fs.h; it, too, is not included from here. */
77 static inline void wait_on_inode(struct inode
*inode
)
80 wait_on_bit(&inode
->i_state
, __I_LOCK
, inode_wait
,
81 TASK_UNINTERRUPTIBLE
);
83 static inline void inode_sync_wait(struct inode
*inode
)
86 wait_on_bit(&inode
->i_state
, __I_SYNC
, inode_wait
,
87 TASK_UNINTERRUPTIBLE
);
94 int wakeup_pdflush(long nr_pages
);
95 void laptop_io_completion(void);
96 void laptop_sync_completion(void);
97 void throttle_vm_writeout(gfp_t gfp_mask
);
99 /* These are exported to sysctl. */
100 extern int dirty_background_ratio
;
101 extern int vm_dirty_ratio
;
102 extern int dirty_writeback_interval
;
103 extern int dirty_expire_interval
;
104 extern int vm_highmem_is_dirtyable
;
105 extern int block_dump
;
106 extern int laptop_mode
;
108 extern int dirty_ratio_handler(struct ctl_table
*table
, int write
,
109 struct file
*filp
, void __user
*buffer
, size_t *lenp
,
114 int dirty_writeback_centisecs_handler(struct ctl_table
*, int, struct file
*,
115 void __user
*, size_t *, loff_t
*);
117 void page_writeback_init(void);
118 void balance_dirty_pages_ratelimited_nr(struct address_space
*mapping
,
119 unsigned long nr_pages_dirtied
);
122 balance_dirty_pages_ratelimited(struct address_space
*mapping
)
124 balance_dirty_pages_ratelimited_nr(mapping
, 1);
127 typedef int (*writepage_t
)(struct page
*page
, struct writeback_control
*wbc
,
130 int pdflush_operation(void (*fn
)(unsigned long), unsigned long arg0
);
131 int generic_writepages(struct address_space
*mapping
,
132 struct writeback_control
*wbc
);
133 int write_cache_pages(struct address_space
*mapping
,
134 struct writeback_control
*wbc
, writepage_t writepage
,
136 int do_writepages(struct address_space
*mapping
, struct writeback_control
*wbc
);
137 int sync_page_range(struct inode
*inode
, struct address_space
*mapping
,
138 loff_t pos
, loff_t count
);
139 int sync_page_range_nolock(struct inode
*inode
, struct address_space
*mapping
,
140 loff_t pos
, loff_t count
);
141 void set_page_dirty_balance(struct page
*page
, int page_mkwrite
);
142 void writeback_set_ratelimit(void);
145 extern int nr_pdflush_threads
; /* Global so it can be exported to sysctl
149 #endif /* WRITEBACK_H */