2 * include/linux/writeback.h.
7 struct backing_dev_info
;
9 extern spinlock_t inode_lock
;
10 extern struct list_head inode_in_use
;
11 extern struct list_head inode_unused
;
14 * Yes, writeback.h requires sched.h
15 * No, sched.h is not included from here.
17 static inline int task_is_pdflush(struct task_struct
*task
)
19 return task
->flags
& PF_FLUSHER
;
22 #define current_is_pdflush() task_is_pdflush(current)
27 enum writeback_sync_modes
{
28 WB_SYNC_NONE
, /* Don't wait on anything */
29 WB_SYNC_ALL
, /* Wait on every mapping */
30 WB_SYNC_HOLD
, /* Hold the inode on sb_dirty for sys_sync() */
34 * A control structure which tells the writeback code what to do. These are
35 * always on the stack, and hence need no locking. They are always initialised
36 * in a manner such that unspecified fields are set to zero.
38 struct writeback_control
{
39 struct backing_dev_info
*bdi
; /* If !NULL, only write back this
41 enum writeback_sync_modes sync_mode
;
42 unsigned long *older_than_this
; /* If !NULL, only write back inodes
44 long nr_to_write
; /* Write this many pages, and decrement
45 this for each page written */
46 long pages_skipped
; /* Pages which were not written */
49 * For a_ops->writepages(): is start or end are non-zero then this is
50 * a hint that the filesystem need only write out the pages inside that
51 * byterange. The byte at `end' is included in the writeout request.
56 unsigned nonblocking
:1; /* Don't get stuck on request queues */
57 unsigned encountered_congestion
:1; /* An output: a queue is full */
58 unsigned for_kupdate
:1; /* A kupdate writeback */
59 unsigned for_reclaim
:1; /* Invoked from the page allocator */
63 * ->writepage() return values (make these much larger than a pagesize, in
64 * case some fs is returning number-of-bytes-written from writepage)
66 #define WRITEPAGE_ACTIVATE 0x80000 /* IO was not started: activate page */
71 void writeback_inodes(struct writeback_control
*wbc
);
72 void wake_up_inode(struct inode
*inode
);
73 int inode_wait(void *);
74 void sync_inodes_sb(struct super_block
*, int wait
);
75 void sync_inodes(int wait
);
77 /* writeback.h requires fs.h; it, too, is not included from here. */
78 static inline void wait_on_inode(struct inode
*inode
)
81 wait_on_bit(&inode
->i_state
, __I_LOCK
, inode_wait
,
82 TASK_UNINTERRUPTIBLE
);
88 int wakeup_pdflush(long nr_pages
);
89 void laptop_io_completion(void);
90 void laptop_sync_completion(void);
91 void throttle_vm_writeout(void);
93 /* These are exported to sysctl. */
94 extern int dirty_background_ratio
;
95 extern int vm_dirty_ratio
;
96 extern int dirty_writeback_centisecs
;
97 extern int dirty_expire_centisecs
;
98 extern int block_dump
;
99 extern int laptop_mode
;
103 int dirty_writeback_centisecs_handler(struct ctl_table
*, int, struct file
*,
104 void __user
*, size_t *, loff_t
*);
106 void page_writeback_init(void);
107 void balance_dirty_pages_ratelimited(struct address_space
*mapping
);
108 int pdflush_operation(void (*fn
)(unsigned long), unsigned long arg0
);
109 int do_writepages(struct address_space
*mapping
, struct writeback_control
*wbc
);
110 int sync_page_range(struct inode
*inode
, struct address_space
*mapping
,
111 loff_t pos
, size_t count
);
112 int sync_page_range_nolock(struct inode
*inode
, struct address_space
113 *mapping
, loff_t pos
, size_t count
);
116 extern int nr_pdflush_threads
; /* Global so it can be exported to sysctl
120 #endif /* WRITEBACK_H */