NFS: populate ->net in mount data when remounting

Otherwise the kernel oopses when remounting with IPv6 server because
net is dereferenced in dev_get_by_name.

Use net ns of current thread so that dev_get_by_name does not operate on
foreign ns. Changing the address is prohibited anyway so this should not
affect anything.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Cc: linux-nfs@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 1a6d7ac..084af10 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2260,6 +2260,7 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
        data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
        data->version = nfsvers;
        data->minorversion = nfss->nfs_client->cl_minorversion;
+       data->net = current->nsproxy->net_ns;
        memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
                data->nfs_server.addrlen);