41  * Before encoding a non-upper directory file handle from real layer N, we need
53  * copied up and renamed, upper dir /a will be indexed by lower dir /a from
93 	/* We can get upper/overlay path from indexed/lower dentry */  in ovl_connectable_layer()
159  * encoding also after copy up. If non-pure upper is not indexed, then it was
161  * about staying consistent with pre copy up encoding and we encode an upper
162  * file handle. Overlay root dentry is a private case of non-indexed upper.
169  *  Pure upper		| U
170  *  Non-indexed upper	| U
171  *  Indexed upper	| L (*)
172  *  Non-upper		| L (*)
174  * U = upper file handle
180  * of a decodable file handle for non-upper dir.
182  * Return 0 for upper file handle, > 0 for lower file handle or < 0 on error.
191 	/* No upper layer? */  in ovl_check_encode_origin()
195 	/* Lower file handle for non-upper non-decodable */  in ovl_check_encode_origin()
199 	/* Upper file handle for pure upper */  in ovl_check_encode_origin()
204 	 * Root is never indexed, so if there's an upper layer, encode upper for  in ovl_check_encode_origin()
211 	 * Upper decodable file handle for non-indexed upper.  in ovl_check_encode_origin()
219 	 * lower dir or under a non-indexed upper is not always possible.  in ovl_check_encode_origin()
235 	/* Lower file handle for indexed and non-upper dir/non-dir */  in ovl_check_encode_origin()
247 	 * Check if we should encode a lower or upper file handle and maybe  in ovl_dentry_to_fid()
254 	/* Encode an upper or lower file handle */  in ovl_dentry_to_fid()
305 	struct dentry *upper = upper_alias ?: index;  in ovl_obtain_alias()  local
314 	if (d_is_dir(upper ?: lower))  in ovl_obtain_alias()
321 	oip.upperdentry = dget(upper);  in ovl_obtain_alias()
330 		dput(upper);  in ovl_obtain_alias()
334 	if (upper)  in ovl_obtain_alias()
348 	ovl_dentry_init_reval(dentry, upper, OVL_I_E(inode));  in ovl_obtain_alias()
360 /* Get the upper or lower dentry in stack whose on layer @idx */
380  * dentry is @real. If @real is on upper layer, we lookup a child overlay
462 	 * Decoding upper dir from index is expensive, so first try to lookup  in ovl_lookup_real_inode()
483 	/* Get connected upper overlay dir from index */  in ovl_lookup_real_inode()
485 		struct dentry *upper = ovl_index_upper(ofs, index, true);  in ovl_lookup_real_inode()  local
488 		if (IS_ERR_OR_NULL(upper))  in ovl_lookup_real_inode()
489 			return upper;  in ovl_lookup_real_inode()
493 		 * ovl_lookup_real() in upper layer. The first level call walks  in ovl_lookup_real_inode()
495 		 * recursive call walks back from indexed upper to the topmost  in ovl_lookup_real_inode()
496 		 * connected/hashed upper parent (or up to root).  in ovl_lookup_real_inode()
498 		this = ovl_lookup_real(sb, upper, &ofs->layers[0]);  in ovl_lookup_real_inode()
499 		dput(upper);  in ovl_lookup_real_inode()
567  * If @real is on upper layer, we lookup a child overlay dentry with the same
670  * Get an overlay dentry from upper/lower real dentries and index.
673 				     struct dentry *upper,  in ovl_get_dentry()  argument
678 	const struct ovl_layer *layer = upper ? &ofs->layers[0] : lowerpath->layer;  in ovl_get_dentry()
679 	struct dentry *real = upper ?: (index ?: lowerpath->dentry);  in ovl_get_dentry()
686 		return ovl_obtain_alias(sb, upper, lowerpath, index);  in ovl_get_dentry()
704 	struct dentry *upper;  in ovl_upper_fh_to_d()  local
709 	upper = ovl_decode_real_fh(ofs, fh, ovl_upper_mnt(ofs), true);  in ovl_upper_fh_to_d()
710 	if (IS_ERR_OR_NULL(upper))  in ovl_upper_fh_to_d()
711 		return upper;  in ovl_upper_fh_to_d()
713 	dentry = ovl_get_dentry(sb, upper, NULL, NULL);  in ovl_upper_fh_to_d()
714 	dput(upper);  in ovl_upper_fh_to_d()
749 	/* Then lookup indexed upper/whiteout by origin fh */  in ovl_lower_fh_to_d()
759 	/* Then try to get a connected upper dir by index */  in ovl_lower_fh_to_d()
761 		struct dentry *upper = ovl_index_upper(ofs, index, true);  in ovl_lower_fh_to_d()  local
763 		err = PTR_ERR(upper);  in ovl_lower_fh_to_d()
764 		if (IS_ERR_OR_NULL(upper))  in ovl_lower_fh_to_d()
767 		dentry = ovl_get_dentry(sb, upper, NULL, NULL);  in ovl_lower_fh_to_d()
768 		dput(upper);  in ovl_lower_fh_to_d()
786 	/* Get a connected non-upper dir or disconnected non-dir */  in ovl_lower_fh_to_d()