fs: move i_wb_list out from under inode_lock
[linux-3.10.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 spinlock_t inode_wb_list_lock;
14
15 /*
16  * fs/fs-writeback.c
17  */
18 enum writeback_sync_modes {
19         WB_SYNC_NONE,   /* Don't wait on anything */
20         WB_SYNC_ALL,    /* Wait on every mapping */
21 };
22
23 /*
24  * A control structure which tells the writeback code what to do.  These are
25  * always on the stack, and hence need no locking.  They are always initialised
26  * in a manner such that unspecified fields are set to zero.
27  */
28 struct writeback_control {
29         enum writeback_sync_modes sync_mode;
30         unsigned long *older_than_this; /* If !NULL, only write back inodes
31                                            older than this */
32         unsigned long wb_start;         /* Time writeback_inodes_wb was
33                                            called. This is needed to avoid
34                                            extra jobs and livelock */
35         long nr_to_write;               /* Write this many pages, and decrement
36                                            this for each page written */
37         long pages_skipped;             /* Pages which were not written */
38
39         /*
40          * For a_ops->writepages(): is start or end are non-zero then this is
41          * a hint that the filesystem need only write out the pages inside that
42          * byterange.  The byte at `end' is included in the writeout request.
43          */
44         loff_t range_start;
45         loff_t range_end;
46
47         unsigned nonblocking:1;         /* Don't get stuck on request queues */
48         unsigned encountered_congestion:1; /* An output: a queue is full */
49         unsigned for_kupdate:1;         /* A kupdate writeback */
50         unsigned for_background:1;      /* A background writeback */
51         unsigned for_reclaim:1;         /* Invoked from the page allocator */
52         unsigned range_cyclic:1;        /* range_start is cyclic */
53         unsigned more_io:1;             /* more io to be dispatched */
54 };
55
56 /*
57  * fs/fs-writeback.c
58  */     
59 struct bdi_writeback;
60 int inode_wait(void *);
61 void writeback_inodes_sb(struct super_block *);
62 void writeback_inodes_sb_nr(struct super_block *, unsigned long nr);
63 int writeback_inodes_sb_if_idle(struct super_block *);
64 int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr);
65 void sync_inodes_sb(struct super_block *);
66 void writeback_inodes_wb(struct bdi_writeback *wb,
67                 struct writeback_control *wbc);
68 long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
69 void wakeup_flusher_threads(long nr_pages);
70
71 /* writeback.h requires fs.h; it, too, is not included from here. */
72 static inline void wait_on_inode(struct inode *inode)
73 {
74         might_sleep();
75         wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
76 }
77 static inline void inode_sync_wait(struct inode *inode)
78 {
79         might_sleep();
80         wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
81                                                         TASK_UNINTERRUPTIBLE);
82 }
83
84
85 /*
86  * mm/page-writeback.c
87  */
88 #ifdef CONFIG_BLOCK
89 void laptop_io_completion(struct backing_dev_info *info);
90 void laptop_sync_completion(void);
91 void laptop_mode_sync(struct work_struct *work);
92 void laptop_mode_timer_fn(unsigned long data);
93 #else
94 static inline void laptop_sync_completion(void) { }
95 #endif
96 void throttle_vm_writeout(gfp_t gfp_mask);
97
98 /* These are exported to sysctl. */
99 extern int dirty_background_ratio;
100 extern unsigned long dirty_background_bytes;
101 extern int vm_dirty_ratio;
102 extern unsigned long vm_dirty_bytes;
103 extern unsigned int dirty_writeback_interval;
104 extern unsigned int dirty_expire_interval;
105 extern int vm_highmem_is_dirtyable;
106 extern int block_dump;
107 extern int laptop_mode;
108
109 extern unsigned long determine_dirtyable_memory(void);
110
111 extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
112                 void __user *buffer, size_t *lenp,
113                 loff_t *ppos);
114 extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
115                 void __user *buffer, size_t *lenp,
116                 loff_t *ppos);
117 extern int dirty_ratio_handler(struct ctl_table *table, int write,
118                 void __user *buffer, size_t *lenp,
119                 loff_t *ppos);
120 extern int dirty_bytes_handler(struct ctl_table *table, int write,
121                 void __user *buffer, size_t *lenp,
122                 loff_t *ppos);
123
124 struct ctl_table;
125 int dirty_writeback_centisecs_handler(struct ctl_table *, int,
126                                       void __user *, size_t *, loff_t *);
127
128 void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
129 unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
130                                unsigned long dirty);
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 void tag_pages_for_writeback(struct address_space *mapping,
148                              pgoff_t start, pgoff_t end);
149 int write_cache_pages(struct address_space *mapping,
150                       struct writeback_control *wbc, writepage_t writepage,
151                       void *data);
152 int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
153 void set_page_dirty_balance(struct page *page, int page_mkwrite);
154 void writeback_set_ratelimit(void);
155 void tag_pages_for_writeback(struct address_space *mapping,
156                              pgoff_t start, pgoff_t end);
157
158 /* pdflush.c */
159 extern int nr_pdflush_threads;  /* Global so it can be exported to sysctl
160                                    read-only. */
161
162
163 #endif          /* WRITEBACK_H */