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/**

 *	file_update_time-- update mtime and ctime time *	@file: file accessed * *	Update the mtime and ctime members of an inode and mark the inode *	for writeback.  Note that this function is meant exclusively for *	usage in the file write path of filesystems, and filesystems may *	choose to explicitly ignore update via this function with the *	S_NOCMTIME inode flag, e.g. for network filesystem where these *	timestamps are handled by the server.  This can return an error for *	file systems who need to allocate space in order to update an inode. */int file_update_time(struct file *file){	struct inode *inode = file_inode(file);	struct timespec now;	int sync_it = 0;	int ret;	/* First try to exhaust all avenues to not sync */	if (IS_NOCMTIME(inode))		return 0;	now = current_time(inode);	if (!timespec_equal(&inode->i_mtime, &now))		sync_it = S_MTIME;	if (!timespec_equal(&inode->i_ctime, &now))		sync_it |= S_CTIME;	if (IS_I_VERSION(inode))		sync_it |= S_VERSION;	if (!sync_it)		return 0;	/* Finally allowed to write? Takes lock. */	if (__mnt_want_write_file(file))		return 0;	ret = update_time(inode, &now, sync_it);	__mnt_drop_write_file(file);	return ret;}

/* * This does the actual work of updating an inodes time or version.  Must have * had called mnt_want_write() before calling this. */static int update_time(struct inode *inode, struct timespec *time, int flags){	int (*update_time)(struct inode *, struct timespec *, int);	update_time = inode->i_op->update_time ? inode->i_op->update_time :		generic_update_time;	return update_time(inode, time, flags);}

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