CIFSSMBLock
return CIFSSMBLock(0, tcon, net_fid, current->tgid, 0, 0, 0, 0,
return CIFSSMBLock(xid, tlink_tcon(cfile->tlink), cfile->fid.netfid,
int CIFSSMBLock(const unsigned int xid, struct cifs_tcon *tcon,