Block all signal except those which are set for explicit handling in glusterfs_signals_setup(). Since thread spawning code in libglusterfs and xlators can get called from application threads when used through libgfapi, it is necessary to do this blocking. Change-Id: Ia320f80521a83d2edcda50b9ad414583a0175281 BUG: 1011662 Signed-off-by: Anand Avati <avati@redhat.com> Reviewed-on: http://review.gluster.org/5995 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Amar Tumballi <amarts@redhat.com> Reviewed-by: Vijay Bellur <vbellur@redhat.com>