Merge tag '5.19-rc6-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three smb3 client fixes:

   - two multichannel fixes: fix a potential deadlock freeing a channel,
     and fix a race condition on failed creation of a new channel

   - mount failure fix: work around a server bug in some common older
     Samba servers by avoiding padding at the end of the negotiate
     protocol request"

* tag '5.19-rc6-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: workaround negprot bug in some Samba servers
  cifs: remove unnecessary locking of chan_lock while freeing session
  cifs: fix race condition with delayed threads

fs/cifs/connect.c

@@ -1918,7 +1918,6 @@ void cifs_put_smb_ses(struct cifs_ses *ses)
 	list_del_init(&ses->smb_ses_list);
 	spin_unlock(&cifs_tcp_ses_lock);
 
-	spin_lock(&ses->chan_lock);
 	chan_count = ses->chan_count;
 
 	/* close any extra channels */
@@ -1934,7 +1933,6 @@ void cifs_put_smb_ses(struct cifs_ses *ses)
 			ses->chans[i].server = NULL;
 		}
 	}
-	spin_unlock(&ses->chan_lock);
 
 	sesInfoFree(ses);
 	cifs_put_tcp_session(server, 0);

fs/cifs/sess.c

@@ -474,6 +474,14 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 
 out:
 	if (rc && chan->server) {
+		/*
+		 * we should avoid race with these delayed works before we
+		 * remove this channel
+		 */
+		cancel_delayed_work_sync(&chan->server->echo);
+		cancel_delayed_work_sync(&chan->server->resolve);
+		cancel_delayed_work_sync(&chan->server->reconnect);
+
 		spin_lock(&ses->chan_lock);
 		/* we rely on all bits beyond chan_count to be clear */
 		cifs_chan_clear_need_reconnect(ses, chan->server);
@@ -484,10 +492,9 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 		 */
 		WARN_ON(ses->chan_count < 1);
 		spin_unlock(&ses->chan_lock);
-	}
 
-	if (rc && chan->server)
 		cifs_put_tcp_session(chan->server, 0);
+	}
 
 	return rc;
 }

fs/cifs/smb2pdu.c

@@ -571,10 +571,6 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	*total_len += ctxt_len;
 	pneg_ctxt += ctxt_len;
 
-	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
-	*total_len += sizeof(struct smb2_posix_neg_context);
-	pneg_ctxt += sizeof(struct smb2_posix_neg_context);
-
 	/*
 	 * secondary channels don't have the hostname field populated
 	 * use the hostname field in the primary channel instead
@@ -586,9 +582,14 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 					      hostname);
 		*total_len += ctxt_len;
 		pneg_ctxt += ctxt_len;
-		neg_context_count = 4;
-	} else /* second channels do not have a hostname */
 		neg_context_count = 3;
+	} else
+		neg_context_count = 2;
+
+	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
+	*total_len += sizeof(struct smb2_posix_neg_context);
+	pneg_ctxt += sizeof(struct smb2_posix_neg_context);
+	neg_context_count++;
 
 	if (server->compress_algorithm) {
 		build_compression_ctxt((struct smb2_compression_capabilities_context *)