98 		 * (upper fsid is 0). This way overlay inode numbers are unique  in ovl_map_dev_ino()
131 		 * is unique per lower fs. Upper layer uses real st_dev and  in ovl_map_dev_ino()
187 			 * upper files, so we cannot use the lower origin st_ino  in ovl_getattr()
197 			 * upper hardlink is not broken and that a redirected  in ovl_getattr()
224 			 * no origin on upper, we can end up here.  in ovl_getattr()
251 	 * Return the overlay inode nlinks for indexed upper inodes.  in ovl_getattr()
252 	 * Overlay inode nlink counts the union of the upper hardlinks  in ovl_getattr()
253 	 * and non-covered lower hardlinks. It does not include the upper  in ovl_getattr()
560 	 * upper inode i_ino on ovl_inode_init() or ovl_inode_update().  in ovl_fill_inode()
601  * With inodes index enabled, an overlay inode nlink counts the union of upper
603  * upper inode, the following nlink modifying operations can happen:
606  * 2. Upper hardlink created, unlinked or renamed over
610  * operation succeeds or fails, but the upper inode nlink may change.
614  * For the second, upper hardlink case, the union nlink should be incremented
616  * upper inode. Therefore, before link/unlink/rename, we store the union nlink
617  * value relative to the upper inode nlink in the index inode.
621  * upper inode where the nlink xattr can be stored before the copied up upper
629  * nlink relative to the upper inode - "U[+-]NUM"
727 	 * checks, so NULL lower/upper in dentry must match NULL lower/upper in  in ovl_verify_inode()
729 	 * 'unknown' lower/upper.  in ovl_verify_inode()
732 		/* Real lower dir moved to upper layer under us? */  in ovl_verify_inode()
829 static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,  in ovl_hash_bylower()  argument
834 	/* No, if pure upper */  in ovl_hash_bylower()
847 	if ((upper || !ovl_indexdir(sb)) &&  in ovl_hash_bylower()
851 	/* No, if non-indexed upper with NFS export */  in ovl_hash_bylower()
852 	if (sb->s_export_op && upper)  in ovl_hash_bylower()
887 	 * Copy up origin (lower) may exist for non-indexed upper, but we must  in ovl_get_inode()