36  * Before encoding a non-upper directory file handle from real layer N, we need
48  * copied up and renamed, upper dir /a will be indexed by lower dir /a from
88 	/* We can get upper/overlay path from indexed/lower dentry */  in ovl_connectable_layer()
154  * encoding also after copy up. If non-pure upper is not indexed, then it was
156  * about staying consistent with pre copy up encoding and we encode an upper
157  * file handle. Overlay root dentry is a private case of non-indexed upper.
164  *  Pure upper		| U
165  *  Non-indexed upper	| U
166  *  Indexed upper	| L (*)
167  *  Non-upper		| L (*)
169  * U = upper file handle
175  * of a decodable file handle for non-upper dir.
177  * Return 0 for upper file handle, > 0 for lower file handle or < 0 on error.
184 	/* No upper layer? */  in ovl_check_encode_origin()
188 	/* Lower file handle for non-upper non-decodable */  in ovl_check_encode_origin()
192 	/* Upper file handle for pure 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()
204 	 * Upper decodable file handle for non-indexed upper.  in ovl_check_encode_origin()
212 	 * lower dir or under a non-indexed upper is not always possible.  in ovl_check_encode_origin()
219 	/* Lower file handle for indexed and non-upper dir/non-dir */  in ovl_check_encode_origin()
231 	 * Check if we should encode a lower or upper file handle and maybe  in ovl_dentry_to_fid()
238 	/* Encode an upper or lower file handle */  in ovl_dentry_to_fid()
295 	struct dentry *upper = upper_alias ?: index;  in ovl_obtain_alias()  local
303 	if (d_is_dir(upper ?: lower))  in ovl_obtain_alias()
310 	oip.upperdentry = dget(upper);  in ovl_obtain_alias()
319 		dput(upper);  in ovl_obtain_alias()
323 	if (upper)  in ovl_obtain_alias()
329 /* Get the upper or lower dentry in stack whose on layer @idx */
349  * dentry is @real. If @real is on upper layer, we lookup a child overlay
431 	 * Decoding upper dir from index is expensive, so first try to lookup  in ovl_lookup_real_inode()
452 	/* Get connected upper overlay dir from index */  in ovl_lookup_real_inode()
454 		struct dentry *upper = ovl_index_upper(ofs, index, true);  in ovl_lookup_real_inode()  local
457 		if (IS_ERR_OR_NULL(upper))  in ovl_lookup_real_inode()
458 			return upper;  in ovl_lookup_real_inode()
462 		 * ovl_lookup_real() in upper layer. The first level call walks  in ovl_lookup_real_inode()
464 		 * recursive call walks back from indexed upper to the topmost  in ovl_lookup_real_inode()
465 		 * connected/hashed upper parent (or up to root).  in ovl_lookup_real_inode()
467 		this = ovl_lookup_real(sb, upper, &ofs->layers[0]);  in ovl_lookup_real_inode()
468 		dput(upper);  in ovl_lookup_real_inode()
536  * If @real is on upper layer, we lookup a child overlay dentry with the same
639  * Get an overlay dentry from upper/lower real dentries and index.
642 				     struct dentry *upper,  in ovl_get_dentry()  argument
647 	const struct ovl_layer *layer = upper ? &ofs->layers[0] : lowerpath->layer;  in ovl_get_dentry()
648 	struct dentry *real = upper ?: (index ?: lowerpath->dentry);  in ovl_get_dentry()
655 		return ovl_obtain_alias(sb, upper, lowerpath, index);  in ovl_get_dentry()
673 	struct dentry *upper;  in ovl_upper_fh_to_d()  local
678 	upper = ovl_decode_real_fh(ofs, fh, ovl_upper_mnt(ofs), true);  in ovl_upper_fh_to_d()
679 	if (IS_ERR_OR_NULL(upper))  in ovl_upper_fh_to_d()
680 		return upper;  in ovl_upper_fh_to_d()
682 	dentry = ovl_get_dentry(sb, upper, NULL, NULL);  in ovl_upper_fh_to_d()
683 	dput(upper);  in ovl_upper_fh_to_d()
718 	/* Then lookup indexed upper/whiteout by origin fh */  in ovl_lower_fh_to_d()
728 	/* Then try to get a connected upper dir by index */  in ovl_lower_fh_to_d()
730 		struct dentry *upper = ovl_index_upper(ofs, index, true);  in ovl_lower_fh_to_d()  local
732 		err = PTR_ERR(upper);  in ovl_lower_fh_to_d()
733 		if (IS_ERR_OR_NULL(upper))  in ovl_lower_fh_to_d()
736 		dentry = ovl_get_dentry(sb, upper, NULL, NULL);  in ovl_lower_fh_to_d()
737 		dput(upper);  in ovl_lower_fh_to_d()
755 	/* Get a connected non-upper dir or disconnected non-dir */  in ovl_lower_fh_to_d()