[PATCH] iseries_veth: Make init_connection() & destroy_connection() symmetrical

This patch makes veth_init_connection() and veth_destroy_connection()
symmetrical in that they allocate/deallocate the same data.

Currently if there's an error while initialising connections (ie. ENOMEM)
we call veth_module_cleanup(), however this will oops because we call
driver_unregister() before we've called driver_register(). I've never seen
this actually happen though.

So instead we explicitly call veth_destroy_connection() for each connection,
any that have been set up will be deallocated.

We also fix a potential leak if vio_register_driver() fails.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 22 insertions, 13 deletions

diff --git a/drivers/net/iseries_veth.c b/drivers/net/iseries_veth.c
index 91d79db96e82..ab9fb218d111 100644
--- a/drivers/net/iseries_veth.c
+++ b/drivers/net/iseries_veth.c
@@ -683,6 +683,14 @@ static void veth_stop_connection(u8 rlp)
 
         /* Wait for the state machine to run. */
         flush_scheduled_work();
+}
+
+static void veth_destroy_connection(u8 rlp)
+{
+        struct veth_lpar_connection *cnx = veth_cnx[rlp];
+
+        if (! cnx)
+                return;
 
         if (cnx->num_events > 0)
                 mf_deallocate_lp_events(cnx->remote_lp,
@@ -694,14 +702,6 @@ static void veth_stop_connection(u8 rlp)
                                       HvLpEvent_Type_VirtualLan,
                                       cnx->num_ack_events,
                                       NULL, NULL);
-}
-
-static void veth_destroy_connection(u8 rlp)
-{
-        struct veth_lpar_connection *cnx = veth_cnx[rlp];
-
-        if (! cnx)
-                return;
 
         kfree(cnx->msgs);
         kfree(cnx);
@@ -1441,15 +1441,24 @@ int __init veth_module_init(void)
 
         for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
                 rc = veth_init_connection(i);
-                if (rc != 0) {
-                        veth_module_cleanup();
-                        return rc;
-                }
+                if (rc != 0)
+                        goto error;
         }
 
         HvLpEvent_registerHandler(HvLpEvent_Type_VirtualLan,
                                   &veth_handle_event);
 
-        return vio_register_driver(&veth_driver);
+        rc = vio_register_driver(&veth_driver);
+        if (rc != 0)
+                goto error;
+
+        return 0;
+
+error:
+        for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
+                veth_destroy_connection(i);
+        }
+
+        return rc;
 }
 module_init(veth_module_init);