9p/xen: Add cleanup path in p9_trans_xen_init

commit 80a316ff16276b36d0392a8f8b2f63259857ae98 upstream.

If xenbus_register_frontend() fails in p9_trans_xen_init,
we should call v9fs_unregister_trans() to do cleanup.

Link: http://lkml.kernel.org/r/20190430143933.19368-1-yuehaibing@huawei.com
Cc: stable@vger.kernel.org
Fixes: 868eb122739a ("xen/9pfs: introduce Xen 9pfs transport driver")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index e2fbf36..9daab0d 100644 (file)
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -530,13 +530,19 @@ static struct xenbus_driver xen_9pfs_front_driver = {
 
 static int p9_trans_xen_init(void)
 {
+       int rc;
+
        if (!xen_domain())
                return -ENODEV;
 
        pr_info("Initialising Xen transport for 9pfs\n");
 
        v9fs_register_trans(&p9_xen_trans);
-       return xenbus_register_frontend(&xen_9pfs_front_driver);
+       rc = xenbus_register_frontend(&xen_9pfs_front_driver);
+       if (rc)
+               v9fs_unregister_trans(&p9_xen_trans);
+
+       return rc;
 }
 module_init(p9_trans_xen_init);