From: Roberto Bergantinos Corpas <rbergant@redhat.com>
Date: Fri, 3 Jul 2020 11:29:32 +0200
Subject: [PATCH] cifs`: handle ERRBaduid for SMB1
Git-commit: a3713ec3d775ff9da2e46f6652b23ff598c3ed36
References: bsc#1190317
Patch-mainline: v5.9-rc1

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 <rbergant@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
 fs/cifs/cifsproto.h |  1 +
 fs/cifs/netmisc.c   | 27 +++++++++++++++++++++++++++
 fs/cifs/transport.c |  2 +-
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 7a836ec0438e..ed13be38a265 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -154,6 +154,7 @@ extern int decode_negTokenInit(unsigned char *security_blob, int length,
 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 */);
diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
index b7ca4960d4ca..0e728aac67e9 100644
--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -881,6 +881,33 @@ map_smb_to_linux_error(char *buf, bool logErr)
 	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
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 84433d0653f9..ac7632482736 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -936,7 +936,7 @@ cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 	}
 
 	/* 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 *
-- 
2.33.0