[PATCH 1/3] fs_parser: handle parameters that can be empty and don't have a value

From: Luis Henriques <lhenriques@suse.de>
To: Theodore Ts'o <tytso@mit.edu>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	Miklos Szeredi <miklos@szeredi.hu>,
	Amir Goldstein <amir73il@gmail.com>
Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org,
	Luis Henriques <lhenriques@suse.de>
Subject: [PATCH 1/3] fs_parser: handle parameters that can be empty and don't have a value
Date: Thu, 29 Feb 2024 16:30:08 +0000	[thread overview]
Message-ID: <20240229163011.16248-2-lhenriques@suse.de> (raw)
In-Reply-To: <20240229163011.16248-1-lhenriques@suse.de>

Currently, only parameters that have the fs_parameter_spec 'type' set to
NULL are handled as 'flag' types.  However, parameters that have the
'fs_param_can_be_empty' flag set and their value is NULL should also be
handled as 'flag' type, as their type is set to 'fs_value_is_flag'.

Signed-off-by: Luis Henriques <lhenriques@suse.de>
---
 fs/fs_parser.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/fs_parser.c b/fs/fs_parser.c
index edb3712dcfa5..53f6cb98a3e0 100644
--- a/fs/fs_parser.c
+++ b/fs/fs_parser.c
@@ -119,7 +119,8 @@ int __fs_parse(struct p_log *log,
 	/* Try to turn the type we were given into the type desired by the
 	 * parameter and give an error if we can't.
 	 */
-	if (is_flag(p)) {
+	if (is_flag(p) ||
+	    (!param->string && (p->flags & fs_param_can_be_empty))) {
 		if (param->type != fs_value_is_flag)
 			return inval_plog(log, "Unexpected value for '%s'",
 				      param->key);
