Don't increment mi->usage is alloc_major_info return NULL

Signed-off-by: Vincent Hanquez <vincent@xensource.com>

diff --git a/linux-2.6-xen-sparse/drivers/xen/blkfront/vbd.c b/linux-2.6-xen-sparse/drivers/xen/blkfront/vbd.c
index 01b62e695d628d4c3aa3b8db10668f526932ec20..49a6ab488279c90ce3d8bea2d4af3bf49b5742f0 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/blkfront/vbd.c
+++ b/linux-2.6-xen-sparse/drivers/xen/blkfront/vbd.c
@@ -160,7 +160,8 @@ xlbd_get_major_info(int vdevice)
 
        mi = ((major_info[index] != NULL) ? major_info[index] :
              xlbd_alloc_major_info(major, minor, index));
-       mi->usage++;
+       if (mi)
+               mi->usage++;
        return mi;
 }