get rid of fs_value_is_filename_empty

Its behaviour is identical to that of fs_value_is_filename.
It makes no sense, anyway - LOOKUP_EMPTY affects nothing
whatsoever once the pathname has been imported from userland.
And both fs_value_is_filename and fs_value_is_filename_empty
carry an already imported pathname.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Documentation/filesystems/mount_api.txt

@@ -427,7 +427,6 @@ returned.
 	fs_value_is_string,		Value is a string
 	fs_value_is_blob,		Value is a binary blob
 	fs_value_is_filename,		Value is a filename* + dirfd
-	fs_value_is_filename_empty,	Value is a filename* + dirfd + AT_EMPTY_PATH
 	fs_value_is_file,		Value is an open file (file*)
 
      If there is a value, that value is stored in a union in the struct in one

fs/fs_parser.c

@@ -268,9 +268,6 @@ int fs_lookup_param(struct fs_context *fc,
 			return PTR_ERR(f);
 		put_f = true;
 		break;
-	case fs_value_is_filename_empty:
-		flags = LOOKUP_EMPTY;
-		/* Fall through */
 	case fs_value_is_filename:
 		f = param->name;
 		put_f = false;

fs/fsopen.c

@@ -321,6 +321,7 @@ SYSCALL_DEFINE5(fsconfig,
 	struct fs_context *fc;
 	struct fd f;
 	int ret;
+	int lookup_flags = 0;
 
 	struct fs_parameter param = {
 		.type	= fs_value_is_undefined,
@@ -409,19 +410,12 @@ SYSCALL_DEFINE5(fsconfig,
 			goto out_key;
 		}
 		break;
+	case FSCONFIG_SET_PATH_EMPTY:
+		lookup_flags = LOOKUP_EMPTY;
+		/* fallthru */
 	case FSCONFIG_SET_PATH:
 		param.type = fs_value_is_filename;
-		param.name = getname_flags(_value, 0, NULL);
-		if (IS_ERR(param.name)) {
-			ret = PTR_ERR(param.name);
-			goto out_key;
-		}
-		param.dirfd = aux;
-		param.size = strlen(param.name->name);
-		break;
-	case FSCONFIG_SET_PATH_EMPTY:
-		param.type = fs_value_is_filename_empty;
-		param.name = getname_flags(_value, LOOKUP_EMPTY, NULL);
+		param.name = getname_flags(_value, lookup_flags, NULL);
 		if (IS_ERR(param.name)) {
 			ret = PTR_ERR(param.name);
 			goto out_key;

include/linux/fs_context.h

@@ -54,7 +54,6 @@ enum fs_value_type {
 	fs_value_is_string,		/* Value is a string */
 	fs_value_is_blob,		/* Value is a binary blob */
 	fs_value_is_filename,		/* Value is a filename* + dirfd */
-	fs_value_is_filename_empty,	/* Value is a filename* + dirfd + AT_EMPTY_PATH */
 	fs_value_is_file,		/* Value is a file* */
 };