diff options
Diffstat (limited to 'include/linux/writeback.h')
| -rw-r--r-- | include/linux/writeback.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h new file mode 100644 index 00000000000..76e8903cd20 --- /dev/null +++ b/include/linux/writeback.h @@ -0,0 +1,160 @@ +/* + * include/linux/writeback.h + */ +#ifndef WRITEBACK_H +#define WRITEBACK_H + +#include <linux/sched.h> +#include <linux/fs.h> + +struct backing_dev_info; + +extern spinlock_t inode_lock; +extern struct list_head inode_in_use; +extern struct list_head inode_unused; + +/* + * fs/fs-writeback.c + */ +enum writeback_sync_modes { + WB_SYNC_NONE, /* Don't wait on anything */ + WB_SYNC_ALL, /* Wait on every mapping */ +}; + +/* + * A control structure which tells the writeback code what to do. These are + * always on the stack, and hence need no locking. They are always initialised + * in a manner such that unspecified fields are set to zero. + */ +struct writeback_control { + struct backing_dev_info *bdi; /* If !NULL, only write back this + queue */ + struct super_block *sb; /* if !NULL, only write inodes from + this super_block */ + enum writeback_sync_modes sync_mode; + unsigned long *older_than_this; /* If !NULL, only write back inodes + older than this */ + long nr_to_write; /* Write this many pages, and decrement + this for each page written */ + long pages_skipped; /* Pages which were not written */ + + /* + * For a_ops->writepages(): is start or end are non-zero then this is + * a hint that the filesystem need only write out the pages inside that + * byterange. The byte at `end' is included in the writeout request. + */ + loff_t range_start; + loff_t range_end; + + unsigned nonblocking:1; /* Don't get stuck on request queues */ + unsigned encountered_congestion:1; /* An output: a queue is full */ + unsigned for_kupdate:1; /* A kupdate writeback */ + unsigned for_background:1; /* A background writeback */ + unsigned for_reclaim:1; /* Invoked from the page allocator */ + unsigned range_cyclic:1; /* range_start is cyclic */ + unsigned more_io:1; /* more io to be dispatched */ + /* + * write_cache_pages() won't update wbc->nr_to_write and + * mapping->writeback_index if no_nrwrite_index_update + * is set. write_cache_pages() may write more than we + * requested and we want to make sure nr_to_write and + * writeback_index are updated in a consistent manner + * so we use a single control to update them + */ + unsigned no_nrwrite_index_update:1; +}; + +/* + * fs/fs-writeback.c + */ +struct bdi_writeback; +int inode_wait(void *); +void writeback_inodes_sb(struct super_block *); +int writeback_inodes_sb_if_idle(struct super_block *); +void sync_inodes_sb(struct super_block *); +void writeback_inodes_wbc(struct writeback_control *wbc); +long wb_do_writeback(struct bdi_writeback *wb, int force_wait); +void wakeup_flusher_threads(long nr_pages); + +/* writeback.h requires fs.h; it, too, is not included from here. */ +static inline void wait_on_inode(struct inode *inode) +{ + might_sleep(); + wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE); +} +static inline void inode_sync_wait(struct inode *inode) +{ + might_sleep(); + wait_on_bit(&inode->i_state, __I_SYNC, inode_wait, + TASK_UNINTERRUPTIBLE); +} + + +/* + * mm/page-writeback.c + */ +void laptop_io_completion(void); +void laptop_sync_completion(void); +void throttle_vm_writeout(gfp_t gfp_mask); + +/* These are exported to sysctl. */ +extern int dirty_background_ratio; +extern unsigned long dirty_background_bytes; +extern int vm_dirty_ratio; +extern unsigned long vm_dirty_bytes; +extern unsigned int dirty_writeback_interval; +extern unsigned int dirty_expire_interval; +extern int vm_highmem_is_dirtyable; +extern int block_dump; +extern int laptop_mode; + +extern unsigned long determine_dirtyable_memory(void); + +extern int dirty_background_ratio_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); +extern int dirty_background_bytes_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); +extern int dirty_ratio_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); +extern int dirty_bytes_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); + +struct ctl_table; +int dirty_writeback_centisecs_handler(struct ctl_table *, int, + void __user *, size_t *, loff_t *); + +void get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty, + unsigned long *pbdi_dirty, struct backing_dev_info *bdi); + +void page_writeback_init(void); +void balance_dirty_pages_ratelimited_nr(struct address_space *mapping, + unsigned long nr_pages_dirtied); + +static inline void +balance_dirty_pages_ratelimited(struct address_space *mapping) +{ + balance_dirty_pages_ratelimited_nr(mapping, 1); +} + +typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, + void *data); + +int generic_writepages(struct address_space *mapping, + struct writeback_control *wbc); +int write_cache_pages(struct address_space *mapping, + struct writeback_control *wbc, writepage_t writepage, + void *data); +int do_writepages(struct address_space *mapping, struct writeback_control *wbc); +void set_page_dirty_balance(struct page *page, int page_mkwrite); +void writeback_set_ratelimit(void); + +/* pdflush.c */ +extern int nr_pdflush_threads; /* Global so it can be exported to sysctl + read-only. */ + + +#endif /* WRITEBACK_H */ |