/* * 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; /* * Yes, writeback.h requires sched.h * No, sched.h is not included from here. */ static inline int task_is_pdflush(struct task_struct *task) { return task->flags & PF_FLUSHER; } #define current_is_pdflush() task_is_pdflush(current) /* * 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 */ 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_reclaim:1; /* Invoked from the page allocator */ unsigned for_writepages:1; /* This is a writepages() call */ 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 */ void writeback_inodes(struct writeback_control *wbc); int inode_wait(void *); void sync_inodes_sb(struct super_block *, int wait); void sync_inodes(int wait); /* 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_LOCK, 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 */ int wakeup_pdflush(long nr_pages); 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 int dirty_writeback_interval; extern 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, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); extern int dirty_background_bytes_handler(struct ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); extern int dirty_ratio_handler(struct ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); extern int dirty_bytes_handler(struct ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); struct ctl_table; struct file; int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *, 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 pdflush_operation(void (*fn)(unsigned long), unsigned long arg0); 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); int sync_page_range(struct inode *inode, struct address_space *mapping, loff_t pos, loff_t count); int sync_page_range_nolock(struct inode *inode, struct address_space *mapping, loff_t pos, loff_t count); 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 */