Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * include/linux/writeback.h. |
| 3 | */ |
| 4 | #ifndef WRITEBACK_H |
| 5 | #define WRITEBACK_H |
| 6 | |
| 7 | struct backing_dev_info; |
| 8 | |
| 9 | extern spinlock_t inode_lock; |
| 10 | extern struct list_head inode_in_use; |
| 11 | extern struct list_head inode_unused; |
| 12 | |
| 13 | /* |
| 14 | * Yes, writeback.h requires sched.h |
| 15 | * No, sched.h is not included from here. |
| 16 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame^] | 17 | static inline int task_is_pdflush(struct task_struct *task) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame^] | 19 | return task->flags & PF_FLUSHER; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | } |
| 21 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame^] | 22 | #define current_is_pdflush() task_is_pdflush(current) |
| 23 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | /* |
| 25 | * fs/fs-writeback.c |
| 26 | */ |
| 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() */ |
| 31 | }; |
| 32 | |
| 33 | /* |
| 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. |
| 37 | */ |
| 38 | struct writeback_control { |
| 39 | struct backing_dev_info *bdi; /* If !NULL, only write back this |
| 40 | queue */ |
| 41 | enum writeback_sync_modes sync_mode; |
| 42 | unsigned long *older_than_this; /* If !NULL, only write back inodes |
| 43 | older than this */ |
| 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 */ |
| 47 | |
| 48 | /* |
| 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. |
| 52 | */ |
| 53 | loff_t start; |
| 54 | loff_t end; |
| 55 | |
| 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 */ |
| 60 | }; |
| 61 | |
| 62 | /* |
| 63 | * ->writepage() return values (make these much larger than a pagesize, in |
| 64 | * case some fs is returning number-of-bytes-written from writepage) |
| 65 | */ |
| 66 | #define WRITEPAGE_ACTIVATE 0x80000 /* IO was not started: activate page */ |
| 67 | |
| 68 | /* |
| 69 | * fs/fs-writeback.c |
| 70 | */ |
| 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); |
| 76 | |
| 77 | /* writeback.h requires fs.h; it, too, is not included from here. */ |
| 78 | static inline void wait_on_inode(struct inode *inode) |
| 79 | { |
| 80 | might_sleep(); |
| 81 | wait_on_bit(&inode->i_state, __I_LOCK, inode_wait, |
| 82 | TASK_UNINTERRUPTIBLE); |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * mm/page-writeback.c |
| 87 | */ |
| 88 | int wakeup_bdflush(long nr_pages); |
| 89 | void laptop_io_completion(void); |
| 90 | void laptop_sync_completion(void); |
| 91 | void throttle_vm_writeout(void); |
| 92 | |
| 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; |
| 100 | |
| 101 | struct ctl_table; |
| 102 | struct file; |
| 103 | int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *, |
| 104 | void __user *, size_t *, loff_t *); |
| 105 | |
| 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); |
| 114 | |
| 115 | /* pdflush.c */ |
| 116 | extern int nr_pdflush_threads; /* Global so it can be exported to sysctl |
| 117 | read-only. */ |
| 118 | |
| 119 | |
| 120 | #endif /* WRITEBACK_H */ |