Add a reference to sunrpc in svc_addsock

The svc_addsock function adds transport instances without taking a
reference on the sunrpc.ko module, however, the generic transport
destruction code drops a reference when a transport instance
is destroyed.

Add a try_module_get call to the svc_addsock function for transport
instances added by this function.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Tested-by: Jeff Moyer <jmoyer@redhat.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 95293f549e9c..a1951dcc5776 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1183,7 +1183,11 @@ int svc_addsock(struct svc_serv *serv,
         else if (so->state > SS_UNCONNECTED)
                 err = -EISCONN;
         else {
-                svsk = svc_setup_socket(serv, so, &err, SVC_SOCK_DEFAULTS);
+                if (!try_module_get(THIS_MODULE))
+                        err = -ENOENT;
+                else
+                        svsk = svc_setup_socket(serv, so, &err,
+                                                SVC_SOCK_DEFAULTS);
                 if (svsk) {
                         struct sockaddr_storage addr;
                         struct sockaddr *sin = (struct sockaddr *)&addr;
@@ -1196,7 +1200,8 @@ int svc_addsock(struct svc_serv *serv,
                         spin_unlock_bh(&serv->sv_lock);
                         svc_xprt_received(&svsk->sk_xprt);
                         err = 0;
-                }
+                } else
+                        module_put(THIS_MODULE);
         }
         if (err) {
                 sockfd_put(so);