X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Fcifs%2Fcifssmb.c;h=54b9f5d8d1dbf94a422d212039b45ea3862c5098;hb=766fdbb57fdb1e53bc34c431103e95383d7f13ba;hp=3652cc60314ceea3f19ac3ec1714e93b94b85433;hpb=a6827c184ea9f5452e4aaa7c799dd3c7cc9ba05e;p=firefly-linux-kernel-4.4.55.git

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 3652cc60314c..54b9f5d8d1db 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -706,6 +706,53 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
 	return rc;
 }
 
+/*
+ * This is a no-op for now. We're not really interested in the reply, but
+ * rather in the fact that the server sent one and that server->lstrp
+ * gets updated.
+ *
+ * FIXME: maybe we should consider checking that the reply matches request?
+ */
+static void
+cifs_echo_callback(struct mid_q_entry *mid)
+{
+	struct TCP_Server_Info *server = mid->callback_data;
+
+	DeleteMidQEntry(mid);
+	atomic_dec(&server->inFlight);
+	wake_up(&server->request_q);
+}
+
+int
+CIFSSMBEcho(struct TCP_Server_Info *server)
+{
+	ECHO_REQ *smb;
+	int rc = 0;
+
+	cFYI(1, "In echo request");
+
+	rc = small_smb_init(SMB_COM_ECHO, 0, NULL, (void **)&smb);
+	if (rc)
+		return rc;
+
+	/* set up echo request */
+	smb->hdr.Tid = cpu_to_le16(0xffff);
+	smb->hdr.WordCount = cpu_to_le16(1);
+	smb->EchoCount = cpu_to_le16(1);
+	smb->ByteCount = cpu_to_le16(1);
+	smb->Data[0] = 'a';
+	smb->hdr.smb_buf_length += 3;
+
+	rc = cifs_call_async(server, (struct smb_hdr *)smb,
+				cifs_echo_callback, server);
+	if (rc)
+		cFYI(1, "Echo request failed: %d", rc);
+
+	cifs_small_buf_release(smb);
+
+	return rc;
+}
+
 int
 CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
 {