cifs`: handle ERRBaduid for SMB1

If server returns ERRBaduid but does not reset transport connection,
we'll keep sending command with a non-valid UID for the server as long
as transport is healthy, without actually recovering. This have been
observed on the field.

This patch adds ERRBaduid handling so that we set CifsNeedReconnect.

map_and_check_smb_error() can be modified to extend use cases.

Signed-off-by: Roberto Bergantinos Corpas <[e-mail]>
Signed-off-by: Steve French <[e-mail]>
Reviewed-by: Ronnie Sahlberg <[e-mail]>

fs/cifs/cifsproto.h

···
 extern int cifs_convert_address(struct sockaddr *dst, const char *src, int len);
 extern void cifs_set_port(struct sockaddr *addr, const unsigned short int port);
 extern int map_smb_to_linux_error(char *buf, bool logErr);
+extern int map_and_check_smb_error(struct mid_q_entry *mid, bool logErr);
 extern void header_assemble(struct smb_hdr *, char /* command */ ,
 			    const struct cifs_tcon *, int /* length of
 			    fixed section (word count) in two byte units */);

fs/cifs/netmisc.c

···
 	return rc;
 }
 
+int
+map_and_check_smb_error(struct mid_q_entry *mid, bool logErr)
+{
+	int rc;
+	struct smb_hdr *smb = (struct smb_hdr *)mid->resp_buf;
+
+	rc = map_smb_to_linux_error((char *)smb, logErr);
+	if (rc == -EACCES && !(smb->Flags2 & SMBFLG2_ERR_STATUS)) {
+		/* possible ERRBaduid */
+		__u8 class = smb->Status.DosError.ErrorClass;
+		__u16 code = le16_to_cpu(smb->Status.DosError.Error);
+
+		/* switch can be used to handle different errors */
+		if (class == ERRSRV && code == ERRbaduid) {
+			cifs_dbg(FYI, "Server returned 0x%x, reconnecting session...\n",
+				code);
+			spin_lock(&GlobalMid_Lock);
+			if (mid->server->tcpStatus != CifsExiting)
+				mid->server->tcpStatus = CifsNeedReconnect;
+			spin_unlock(&GlobalMid_Lock);
+		}
+	}
+
+	return rc;
+}
+
+
 /*
  * calculate the size of the SMB message based on the fixed header
  * portion, the number of word parameters and the data portion of the message

fs/cifs/transport.c

···
 	}
 
 	/* BB special case reconnect tid and uid here? */
-	return map_smb_to_linux_error(mid->resp_buf, log_error);
+	return map_and_check_smb_error(mid, log_error);
 }
 
 struct mid_q_entry *