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From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-renesas-soc@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Christian Brauner <brauner@kernel.org>,
	Eric Sandeen <sandeen@redhat.com>,
	David Howells <dhowells@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] debugfs: ignore auto and noauto options if given
Date: Wed, 22 May 2024 10:38:51 +0200
Message-Id: <20240522083851.37668-1-wsa+renesas@sang-engineering.com>
Precedence: bulk
MIME-Version: 1.0
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The 'noauto' and 'auto' options were missed when migrating to the new
mount API. As a result, users with these in their fstab mount options
are now unable to mount debugfs filesystems, as they'll receive an
"Unknown parameter" error.

This restores the old behaviour of ignoring noauto and auto if they're
given.

Fixes: a20971c18752 ("vfs: Convert debugfs to use the new mount API")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

With current top-of-tree, debugfs remained empty on my boards triggering
the message "debugfs: Unknown parameter 'auto'". I applied a similar fix
which CIFS got and largely reused the commit message from 19d51588125f
("cifs: ignore auto and noauto options if given").

Given the comment in debugfs_parse_param(), I am not sure if this patch
is a complete fix or if there are more options to be ignored. This patch
makes it work for me(tm), however.

From my light research, tracefs (which was converted to new mount API
together with debugfs) doesn't need the same fixing. But I am not
super-sure about that.

Looking forward to comments.


 fs/debugfs/inode.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index dc51df0b118d..915f0b618486 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -89,12 +89,14 @@ enum {
 	Opt_uid,
 	Opt_gid,
 	Opt_mode,
+	Opt_ignore,
 };
 
 static const struct fs_parameter_spec debugfs_param_specs[] = {
 	fsparam_u32	("gid",		Opt_gid),
 	fsparam_u32oct	("mode",	Opt_mode),
 	fsparam_u32	("uid",		Opt_uid),
+	fsparam_flag_no	("auto",	Opt_ignore),
 	{}
 };
 
-- 
2.39.2