44  * Before encoding a non-upper directory file handle from real layer N, we need
56  * copied up and renamed, upper dir /a will be indexed by lower dir /a from
96 	/* We can get upper/overlay path from indexed/lower dentry */  in ovl_connectable_layer()
161  * encoding also after copy up. If non-pure upper is not indexed, then it was
163  * about staying consistent with pre copy up encoding and we encode an upper
164  * file handle. Overlay root dentry is a private case of non-indexed upper.
171  *  Pure upper		| U
172  *  Non-indexed upper	| U
173  *  Indexed upper	| L (*)
174  *  Non-upper		| L (*)
176  * U = upper file handle
184  * Return 0 for upper file handle, > 0 for lower file handle or < 0 on error.
190 	/* Upper file handle for pure upper */  in ovl_check_encode_origin()
195 	 * Upper file handle for non-indexed upper.  in ovl_check_encode_origin()
197 	 * Root is never indexed, so if there's an upper layer, encode upper for  in ovl_check_encode_origin()
206 	 * lower dir or under a non-indexed upper is not always possible.  in ovl_check_encode_origin()
213 	/* Lower file handle for indexed and non-upper dir/non-dir */  in ovl_check_encode_origin()
223 	 * Check if we should encode a lower or upper file handle and maybe  in ovl_d_to_fh()
230 	/* Encode an upper or lower file handle */  in ovl_d_to_fh()
298 	struct dentry *upper = upper_alias ?: index;  in ovl_obtain_alias()  local
309 	if (d_is_dir(upper ?: lower))  in ovl_obtain_alias()
312 	oip.upperdentry = dget(upper);  in ovl_obtain_alias()
315 		dput(upper);  in ovl_obtain_alias()
319 	if (upper)  in ovl_obtain_alias()
348 /* Get the upper or lower dentry in stach whose on layer @idx */
367  * dentry is @real. If @real is on upper layer, we lookup a child overlay
445 	 * Decoding upper dir from index is expensive, so first try to lookup  in ovl_lookup_real_inode()
466 	/* Get connected upper overlay dir from index */  in ovl_lookup_real_inode()
468 		struct dentry *upper = ovl_index_upper(ofs, index);  in ovl_lookup_real_inode()  local
471 		if (IS_ERR_OR_NULL(upper))  in ovl_lookup_real_inode()
472 			return upper;  in ovl_lookup_real_inode()
476 		 * ovl_lookup_real() in upper layer. The first level call walks  in ovl_lookup_real_inode()
478 		 * recursive call walks back from indexed upper to the topmost  in ovl_lookup_real_inode()
479 		 * connected/hashed upper parent (or up to root).  in ovl_lookup_real_inode()
481 		this = ovl_lookup_real(sb, upper, &upper_layer);  in ovl_lookup_real_inode()
482 		dput(upper);  in ovl_lookup_real_inode()
550  * If @real is on upper layer, we lookup a child overlay dentry with the same
653  * Get an overlay dentry from upper/lower real dentries and index.
656 				     struct dentry *upper,  in ovl_get_dentry()  argument
662 	struct ovl_layer *layer = upper ? &upper_layer : lowerpath->layer;  in ovl_get_dentry()
663 	struct dentry *real = upper ?: (index ?: lowerpath->dentry);  in ovl_get_dentry()
670 		return ovl_obtain_alias(sb, upper, lowerpath, index);  in ovl_get_dentry()
688 	struct dentry *upper;  in ovl_upper_fh_to_d()  local
693 	upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);  in ovl_upper_fh_to_d()
694 	if (IS_ERR_OR_NULL(upper))  in ovl_upper_fh_to_d()
695 		return upper;  in ovl_upper_fh_to_d()
697 	dentry = ovl_get_dentry(sb, upper, NULL, NULL);  in ovl_upper_fh_to_d()
698 	dput(upper);  in ovl_upper_fh_to_d()
733 	/* Then lookup indexed upper/whiteout by origin fh */  in ovl_lower_fh_to_d()
743 	/* Then try to get a connected upper dir by index */  in ovl_lower_fh_to_d()
745 		struct dentry *upper = ovl_index_upper(ofs, index);  in ovl_lower_fh_to_d()  local
747 		err = PTR_ERR(upper);  in ovl_lower_fh_to_d()
748 		if (IS_ERR_OR_NULL(upper))  in ovl_lower_fh_to_d()
751 		dentry = ovl_get_dentry(sb, upper, NULL, NULL);  in ovl_lower_fh_to_d()
752 		dput(upper);  in ovl_lower_fh_to_d()
770 	/* Get a connected non-upper dir or disconnected non-dir */  in ovl_lower_fh_to_d()