When qemu close the unix socket fd of the vhostuser as a
server, and then immediately delete the vhostuser port on
openvswitch. There will be a deadlock.
A thread (fdset event thread): B thread:
1. fdset_event_dispatch rte_vhost_driver_unregister
2. set the fd busy to 1. lock vsocket->conn_mutex
3. vhost_user_read_cb fdset_del waits busy changed to 0.
4. vhost peer closed, remove the
conn from vsocket->conn_list:
lock vsocket->conn_mutex
5. set the fd busy to 0
Fixes: 65388b43f592 ("vhost: fix fd leaks for vhost-user server mode")
Cc: stable@dpdk.org
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Maxime Coquelin <maxime.coquelin@redhat.com>
8b4b949144