346  * to return positive, while there's no actual upper alias for the inode.
347  * Copy up code needs to know about the existence of the upper alias, so it
542 	 * Check if copy-up has happened as well as for upper alias (in  in ovl_already_copied_up()
549 	 *      upper dentry is up-to-date  in ovl_already_copied_up()
551 	 *      upper parent i_rwsem to prevent reordering copy-up  in ovl_already_copied_up()
615 #define OVL_XATTR_UPPER_POSTFIX		"upper"
646 		pr_warn("cannot set %s xattr on upper\n", ovl_xattr(ofs, ox));  in ovl_check_setxattr()
663 	 * Do not fail when upper doesn't support xattrs.  in ovl_set_impure()
664 	 * Upper inodes won't have origin nor redirect xattr anyway.  in ovl_set_impure()
676 void ovl_check_protattr(struct inode *inode, struct dentry *upper)  in ovl_check_protattr()  argument
683 	res = ovl_getxattr_upper(ofs, upper, OVL_XATTR_PROTATTR, buf,  in ovl_check_protattr()
689 	 * Initialize inode flags from overlay.protattr xattr and upper inode  in ovl_check_protattr()
690 	 * flags.  If upper inode has those fileattr flags set (i.e. from old  in ovl_check_protattr()
705 				    upper, res);  in ovl_check_protattr()
711 int ovl_set_protattr(struct inode *inode, struct dentry *upper,  in ovl_set_protattr()  argument
731 	 * Do not allow to set protection flags when upper doesn't support  in ovl_set_protattr()
732 	 * xattrs, because we do not set those fileattr flags on upper inode.  in ovl_set_protattr()
736 		err = ovl_check_setxattr(ofs, upper, OVL_XATTR_PROTATTR,  in ovl_set_protattr()
739 		err = ovl_removexattr(ofs, upper, OVL_XATTR_PROTATTR);  in ovl_set_protattr()
748 	/* Mask out the fileattr flags that should not be set in upper inode */  in ovl_set_protattr()
844 		 * overlay nlink to zero before all upper inodes are unlinked.  in ovl_cleanup_index()
883  * Operations that change overlay inode and upper inode nlink need to be
899 	 * first copy up, we have no upper index inode to store the xattr.  in ovl_nlink_start()
902 	 * copy up to create the upper index. Creating the upper index will  in ovl_nlink_start()
925 	 * upper operation succeeds, along with nlink change of upper inode.  in ovl_nlink_start()
927 	 * value relative to the upper inode nlink in an upper inode xattr.  in ovl_nlink_start()
1094  * When overlay copies inode information from an upper or lower layer to the
1095  * relevant overlay inode it will apply the idmapping of the upper or lower
1097  * reflect the ownership of the idmapped upper or lower layer. For example, an
1098  * idmapped upper or lower layer mapping id 1001 to id 1000 will take care to
1099  * map any lower or upper inode owned by id 1001 to id 1000. These mapping