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From: Chen Hanxiao <chenhx.fnst@fujitsu.com>
To: Steve Dickson <steved@redhat.com>
Cc: linux-nfs@vger.kernel.org
Subject: [nfs-utils PATCH] mount: warning "namlen=" option for a NFSv4 mount
Date: Wed,  3 Apr 2024 15:02:28 +0800
Message-Id: <20240403070228.308-1-chenhx.fnst@fujitsu.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

namlen is not a valid option for NFSv4.
Currently, we could pass a namlen=xxx in a NFSv4 mount,
the mount command succeed and namlen is ignored silently

# mount -o vers=4,namlen=100 192.168.122.19:/nfsroot /mnt/ -vvv
mount.nfs: timeout set for Fri Mar 22 14:22:18 2024
mount.nfs: trying text-based options 'namlen=100,vers=4.2,
	   addr=192.168.122.19,clientaddr=192.168.122.15'

This patch will remove "namlen=" option in a NFSv4 mount,
and give a warning message in verbose mode.

Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
---
 utils/mount/stropts.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index dbdd11e7..a92c4200 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -780,6 +780,14 @@ static int nfs_do_mount_v4(struct nfsmount_info *mi,
 		goto out_fail;
 	}
 
+	if (po_contains(options, "namlen")) {
+		po_remove_all(options, "namlen");
+		if (verbose) {
+			printf(_("%s: Ignore unsupported nfs4 mount option 'namlen' in '%s'\n"),
+				progname, *mi->extra_opts);
+		}
+	}
+
 	if (mi->version.v_mode != V_SPECIFIC) {
 		char *fmt;
 		switch (mi->version.minor) {
-- 
2.39.1