rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
(char *)pneg_inbuf, inbuflen, (char **)&pneg_rsp, &rsplen);
-
- if (rc != 0) {
+ if (rc == -EOPNOTSUPP) {
+ /*
+ * Old Windows versions or Netapp SMB server can return
+ * not supported error. Client should accept it.
+ */
+ cifs_dbg(VFS, "Server does not support validate negotiate\n");
+ return 0;
+ } else if (rc != 0) {
cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
rc = -EIO;
goto out_free_inbuf;