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From: Chen Hanxiao <chenhx.fnst@fujitsu.com>
To: Trond Myklebust <trond.myklebust@hammerspace.com>,
	Anna Schumaker <anna@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>,
	linux-nfs@vger.kernel.org
Subject: [PATCH] nfs: fix regression in handling of namlen= option in NFSv4
Date: Wed, 21 Feb 2024 23:16:13 +0800
Message-Id: <20240221151613.555-1-chenhx.fnst@fujitsu.com>
Precedence: bulk
MIME-Version: 1.0
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Setting the maximum length of a pathname component
via the namlen= mount option is currently broken in NFSv4.

This patch will fix this issue.

Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
---
 fs/nfs/namespace.c     | 2 ++
 fs/nfs/nfs4client.c    | 2 ++
 fs/nfs/nfs4namespace.c | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index e7494cdd957e..8da1fc9ebbd4 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -277,6 +277,8 @@ int nfs_do_submount(struct fs_context *fc)
 	if (IS_ERR(server))
 		return PTR_ERR(server);
 
+	if (ctx->namlen)
+		server->namelen = ctx->namlen;
 	ctx->server = server;
 
 	buffer = kmalloc(4096, GFP_USER);
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 11e3a285594c..9826c2fcb0a7 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -1187,6 +1187,8 @@ static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
 		server->rsize = nfs_io_size(ctx->rsize, server->nfs_client->cl_proto);
 	if (ctx->wsize)
 		server->wsize = nfs_io_size(ctx->wsize, server->nfs_client->cl_proto);
+	if (ctx->namlen)
+		server->namelen = ctx->namlen;
 
 	server->acregmin = ctx->acregmin * HZ;
 	server->acregmax = ctx->acregmax * HZ;
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 9a98595bb160..1a30224df7b9 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -465,6 +465,8 @@ int nfs4_submount(struct fs_context *fc, struct nfs_server *server)
 		return PTR_ERR(client);
 
 	ctx->selected_flavor = client->cl_auth->au_flavor;
+	if (server->namelen)
+		ctx->namlen = server->namelen;
 	if (ctx->clone_data.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
 		ret = nfs_do_refmount(fc, client);
 	} else {
-- 
2.39.1