cifs: fail i/o on soft mounts if sessionsetup errors out

commit b0dd940e upstream.

RHBZ: 1579050

If we have a soft mount we should fail commands for session-setup
failures (such as the password having changed/ account being deleted/ ...)
and return an error back to the application.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/cifs/smb2pdu.c

@@ -247,9 +247,14 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
 	 */
 	mutex_lock(&tcon->ses->session_mutex);
 	rc = cifs_negotiate_protocol(0, tcon->ses);
-	if (!rc && tcon->ses->need_reconnect)
+	if (!rc && tcon->ses->need_reconnect) {
 		rc = cifs_setup_session(0, tcon->ses, nls_codepage);
-
+		if ((rc == -EACCES) && !tcon->retry) {
+			rc = -EHOSTDOWN;
+			mutex_unlock(&tcon->ses->session_mutex);
+			goto failed;
+		}
+	}
 	if (rc || !tcon->need_reconnect) {
 		mutex_unlock(&tcon->ses->session_mutex);
 		goto out;
@@ -291,6 +296,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
 	case SMB2_SET_INFO:
 		rc = -EAGAIN;
 	}
+failed:
 	unload_nls(nls_codepage);
 	return rc;
 }