SUNRPC: Use RCU to dereference the rpc_clnt.cl_xprt field

A migration event will replace the rpc_xprt used by an rpc_clnt.  To
ensure this can be done safely, all references to cl_xprt must now use
a form of rcu_dereference().

Special care is taken with rpc_peeraddr2str(), which returns a pointer
to memory whose lifetime is the same as the rpc_xprt.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[ cel: fix lockdep splats and layering violations ]
[ cel: forward ported to 3.4 ]
[ cel: remove rpc_max_reqs(), add rpc_net_ns() ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 667ea7406fd3..9c8eca315f43 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -96,8 +96,8 @@ static int nfs4_validate_fspath(struct dentry *dentry,
 static size_t nfs_parse_server_name(char *string, size_t len,
                 struct sockaddr *sa, size_t salen, struct nfs_server *server)
 {
+        struct net *net = rpc_net_ns(server->client);
         ssize_t ret;
-        struct net *net = server->client->cl_xprt->xprt_net;
 
         ret = rpc_pton(net, string, len, sa, salen);
         if (ret == 0) {