NFS: Save the value of the "port=" mount option

During a remount based on the mount options displayed in /proc/mounts, we
want to preserve the original behavior of the mount request.  Let's save
the original setting of the "port=" mount option in the mount's nfs_server
structure.

This allows us to simplify the default behavior of port setting for NFSv4
mounts: by default, NFSv2/3 mounts first try an RPC bind to determine the
NFS server's port, unless the user specified the "port=" mount option;
Users can force the client to skip the RPC bind by explicitly specifying
"port=<value>".

NFSv4, by contrast, assumes the NFS server port is 2049 and skips the RPC
bind, unless the user specifies "port=".  Users can force an RPC bind for
NFSv4 by explicitly specifying "port=0".

I added a couple of extra comments to clarify this behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 06f064d8fbbe..874018113d0e 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -682,6 +682,8 @@ static int nfs_init_server(struct nfs_server *server,
         if (error < 0)
                 goto error;
 
+        server->port = data->nfs_server.port;
+
         error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
         if (error < 0)
                 goto error;
@@ -1064,6 +1066,8 @@ static int nfs4_init_server(struct nfs_server *server,
         server->acdirmin = data->acdirmin * HZ;
         server->acdirmax = data->acdirmax * HZ;
 
+        server->port = data->nfs_server.port;
+
         error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
 
 error: