cifs: Send a logoff request before removing a smb session

Send a smb session logoff request before removing smb session off of the list.
On a signed smb session, remvoing a session off of the list before sending
a logoff request results in server returning an error for lack of
smb signature.

Never seen an error during smb logoff, so as per MS-SMB2 3.2.5.1,
not sure how an error during logoff should be retried. So for now,
if a server returns an error to a logoff request, log the error and
remove the session off of the list.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 0ee6d249ef6f..b37570952846 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -431,13 +431,20 @@ static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
                 return -EAGAIN;
         }
 
-        if (ses->status != CifsGood) {
-                /* check if SMB session is bad because we are setting it up */
+        if (ses->status == CifsNew) {
                 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
                         (in_buf->Command != SMB_COM_NEGOTIATE))
                         return -EAGAIN;
                 /* else ok - we are setting up session */
         }
+
+        if (ses->status == CifsExiting) {
+                /* check if SMB session is bad because we are setting it up */
+                if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
+                        return -EAGAIN;
+                /* else ok - we are shutting down session */
+        }
+
         *ppmidQ = AllocMidQEntry(in_buf, ses->server);
         if (*ppmidQ == NULL)
                 return -ENOMEM;