When the vhost-user is reconnecting to the backend, and if the vhost-user fails
at the get_features in vhost_dev_init(), then the reconnect will fail
and it will not be retriggered forever.

The reason is:
When the vhost-user fail at get_features, the vhost_dev_cleanup will be called
immediately.

vhost_dev_cleanup calls 'memset(hdev, 0, sizeof(struct vhost_dev))'.

The reconnect path is:
vhost_user_blk_event
   vhost_user_async_close(.. vhost_user_blk_disconnect ..)
     qemu_chr_fe_set_handlers <----- clear the notifier callback
       schedule vhost_user_async_close_bh

The vhost->vdev is null, so the vhost_user_blk_disconnect will not be
called, then the event fd callback will not be reinstalled.

With this patch, the vhost_user_blk_disconnect will call the
vhost_dev_cleanup() again, it's safe.

All vhost-user devices have this issue, including vhost-user-blk/scsi.

Fixes: 71e076a07d ("hw/virtio: generalise CHR_EVENT_CLOSED handling")

Signed-off-by: Li Feng <fengli@smartx.com>
---
 hw/virtio/vhost-user.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index c929097e87..c407ea8939 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -2781,16 +2781,8 @@ typedef struct {
 static void vhost_user_async_close_bh(void *opaque)
 {
     VhostAsyncCallback *data = opaque;
-    struct vhost_dev *vhost = data->vhost;
 
-    /*
-     * If the vhost_dev has been cleared in the meantime there is
-     * nothing left to do as some other path has completed the
-     * cleanup.
-     */
-    if (vhost->vdev) {
-        data->cb(data->dev);
-    }
+    data->cb(data->dev);
 
     g_free(data);
 }
-- 
2.44.0