extern int filemap_fdatawrite_range(struct address_space *mapping,
loff_t start, loff_t end);
-extern long do_fsync(struct file *file, int datasync);
+extern int vfs_fsync(struct file *file, struct dentry *dentry, int datasync);
extern void sync_supers(void);
extern void sync_filesystems(int wait);
extern void __fsync_super(struct super_block *sb);