mount -t cifs -o username=user1,password=passwd1,dir_mode=0777,file_mode=0777,uid=centos7,gid=www //192.168.1.2/www/ /var/www

mount error(115): Operation now in progress
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

==> default: Mounting SMB shared folders...
    default: D:/Vagrant/general => /vagrant
Failed to mount folders in Linux guest. This is usually because
the "vboxsf" file system is not available. Please verify that
the guest additions are properly installed in the guest and
can work properly. The command attempted was:

mount -t cifs -o sec=ntlmssp,credentials=/etc/smb_creds_vgt-  2e7e00e92f59cc95193a0f4a9585a3f6-   6ad5fdbcbf2eaa93bd62f92333a2e6e5,uid=1000,gid=1000 //192.168.1.2/vgt-2e7e00e92f59cc95193a0f4a9585a3f6-6ad5fdbcbf2eaa93bd62f92333a2e6e5 /vagrant

The error output from the last command was:

mount error(115): Operation now in progress
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)