Re: [Bug 14276] nfsroot will not remount rw and claims illegal options

[Trond Myklebust <trond.myklebust@fys.uio.no>]

On Sun, 2009-10-04 at 15:06 -0400, Trond Myklebust wrote:
> Chuck, can you see how the rpc_pton() might be breaking nfsroot?
> The cmdline is of the form
> 
>     root=/dev/nfs nfsroot=10.10.0.2:/nfs/gemini,v3,tcp ro ip=::::::dhcp

I think I see it...

The difference is that rpc_pton4() starts with

	memset(sap, 0, sizeof(struct sockaddr_in));

That clears the port number that was set in nfs_remount(), and so the
comparison in nfs_compare_remount_data() fails.

Does the following patch fix the problem?

--------------------------------------------------------------------------
NFS: Fix port initialisation in nfs_remount()
From: Trond Myklebust <Trond.Myklebust@netapp.com>

The recent changeset 53a0b9c4c99ab0085a06421f71592722e5b3fd5f (NFS: Replace
nfs_parse_ip_address() with rpc_pton()) broke nfs_remount, since the call
to rpc_pton() will zero out the port number in data->nfs_server.address.

This is actually due to a bug in nfs_remount: it should be looking at the
port number in nfs_server.port instead...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---

 fs/nfs/super.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)


diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 0d14704..fb3b280 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1846,9 +1846,10 @@ nfs_compare_remount_data(struct nfs_server *nfss,
 	    data->acdirmin != nfss->acdirmin / HZ ||
 	    data->acdirmax != nfss->acdirmax / HZ ||
 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
+	    data->nfs_server.port != nfss->port ||
 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
-	    memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
-		   data->nfs_server.addrlen) != 0)
+	    !rpc_cmp_addr(&data->nfs_server.address,
+		    &nfss->nfs_client->cl_addr))
 		return -EINVAL;
 
 	return 0;
@@ -1891,6 +1892,7 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
 	data->acdirmin = nfss->acdirmin / HZ;
 	data->acdirmax = nfss->acdirmax / HZ;
 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
+	data->nfs_server.port = nfss->port;
 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
 		data->nfs_server.addrlen);