43  * lower decoded dentry. This is done by following the overlay ancestry up to a
53  * copied up and renamed, upper dir /a will be indexed by lower dir /a from
56  * dentry from the connected lower dentry /a/b/c.
61  * and when the time comes to decode the file handle from lower dentry /a/b/c,
66  * entry /a in the lower layers above layer N and find the indexed dir /a from
68  * will need to verify there are no redirects in lower layers above N. In the
87 	 * lower layer  in ovl_connectable_layer()
93 	/* We can get upper/overlay path from indexed/lower dentry */  in ovl_connectable_layer()
99  * have the same uppermost lower layer as the origin's layer. We may need to
174  * L = lower file handle
176  * (*) Connecting an overlay dir from real lower dentry is not always
177  * possible when there are redirects in lower layers and non-indexed merge dirs.
178  * To mitigate those case, we may copy up the lower dir ancestor before encode
179  * a lower dir file handle.
181  * Return 0 for upper file handle, > 0 for lower file handle or < 0 on error.
203 	 * lower dir or under a non-indexed upper is not always possible.  in ovl_check_encode_origin()
210 	/* Lower file handle for indexed and non-upper dir/non-dir */  in ovl_check_encode_origin()
221 	 * Check if we should encode a lower or upper file handle and maybe  in ovl_dentry_to_fid()
222 	 * copy up an ancestor to make lower file handle connectable.  in ovl_dentry_to_fid()
228 	/* Encode an upper or lower file handle */  in ovl_dentry_to_fid()
283 	struct dentry *lower = lowerpath ? lowerpath->dentry : NULL;  in ovl_obtain_alias()  local
291 		.numlower = !!lower  in ovl_obtain_alias()
295 	if (d_is_dir(upper ?: lower))  in ovl_obtain_alias()
315 	oe = ovl_alloc_entry(lower ? 1 : 0);  in ovl_obtain_alias()
319 	if (lower) {  in ovl_obtain_alias()
320 		oe->lowerstack->dentry = dget(lower);  in ovl_obtain_alias()
340 /* Get the upper or lower dentry in stach whose on layer @idx */
448 	 * For decoded lower dir file handle, lookup index by origin to check  in ovl_lookup_real_inode()
449 	 * if lower dir was copied up and and/or removed.  in ovl_lookup_real_inode()
466 		 * ovl_lookup_real() in lower layer may call recursively once to  in ovl_lookup_real_inode()
468 		 * back lower parents to the topmost indexed parent. The second  in ovl_lookup_real_inode()
644  * Get an overlay dentry from upper/lower real dentries and index.