Add SMB2.02 dialect support

This patch enables optional for original SMB2 (SMB2.02) dialect
by specifying vers=2.0 on mount.

Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 137aaf8..ad4d96a 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -625,6 +625,23 @@
 	.new_lease_key = smb2_new_lease_key,
 };
 
+struct smb_version_values smb20_values = {
+	.version_string = SMB20_VERSION_STRING,
+	.protocol_id = SMB20_PROT_ID,
+	.req_capabilities = 0, /* MBZ */
+	.large_lock_type = 0,
+	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
+	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
+	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
+	.header_size = sizeof(struct smb2_hdr),
+	.max_header_size = MAX_SMB2_HDR_SIZE,
+	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
+	.lock_cmd = SMB2_LOCK,
+	.cap_unix = 0,
+	.cap_nt_find = SMB2_NT_FIND,
+	.cap_large_files = SMB2_LARGE_FILES,
+};
+
 struct smb_version_values smb21_values = {
 	.version_string = SMB21_VERSION_STRING,
 	.protocol_id = SMB21_PROT_ID,