[PATCH 3.16 116/306] Set previous session id correctly on SMB3 reconnect

[Ben Hutchings]

3.16.40-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Steve French <smfre...@gmail.com>

commit c2afb8147e69819885493edf3a7c1ce03aaf2d4e upstream.

Signed-off-by: Steve French <steve.fre...@primarydata.com>
Reported-by: David Goebel <david...@microsoft.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 fs/cifs/smb2pdu.c | 5 +++++
 fs/cifs/smb2pdu.h | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -566,6 +566,7 @@ SMB2_sess_setup(const unsigned int xid,
        char *security_blob;
        unsigned char *ntlmssp_blob = NULL;
        bool use_spnego = false; /* else use raw ntlmssp */
+       u64 previous_session = ses->Suid;
 
        cifs_dbg(FYI, "Session Setup\n");
 
@@ -602,6 +603,10 @@ ssetup_ntlmssp_authenticate:
                return rc;
 
        req->hdr.SessionId = 0; /* First session, not a reauthenticate */
+
+       /* if reconnect, we need to send previous sess id, otherwise it is 0 */
+       req->PreviousSessionId = previous_session;
+
        req->VcNumber = 0; /* MBZ */
        /* to enable echos and oplocks */
        req->hdr.CreditRequest = cpu_to_le16(3);
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -245,7 +245,7 @@ struct smb2_sess_setup_req {
        __le32 Channel;
        __le16 SecurityBufferOffset;
        __le16 SecurityBufferLength;
-       __le64 PreviousSessionId;
+       __u64 PreviousSessionId;
        __u8   Buffer[1];       /* variable length GSS security buffer */
 } __packed;