diff --git a/0001-RBD-Pass-bytes-type-for-mon_command-inbuf.patch b/0001-RBD-Pass-bytes-type-for-mon_command-inbuf.patch
new file mode 100644
index 0000000000000000000000000000000000000000..56c12a16b5996c1a97592b0cacfc7fe18426afa5
--- /dev/null
+++ b/0001-RBD-Pass-bytes-type-for-mon_command-inbuf.patch
@@ -0,0 +1,62 @@
+From aed8e1625494d7232c2629def748a878a0d52dbf Mon Sep 17 00:00:00 2001
+From: zhangy1317 <zhangy1317@chinaunicom.cn>
+Date: Wed, 16 Mar 2022 16:18:08 +0800
+Subject: [PATCH] RBD:Pass-bytes-type-for-mon_command-inbuf
+
+---
+ cinder/tests/unit/volume/drivers/test_rbd.py          | 8 ++++----
+ cinder/volume/drivers/rbd.py  		               | 4 ++--
+ 2 files changed, 6 insertions(+), 6 deletions(-)
+
+diff --git a/cinder/tests/unit/volume/drivers/test_rbd.py b/cinder/tests/unit/volume/drivers/test_rbd.py
+index d20c95a..d7df401 100644
+--- a/cinder/tests/unit/volume/drivers/test_rbd.py
++++ b/cinder/tests/unit/volume/drivers/test_rbd.py
+@@ -1580,9 +1580,9 @@ class RBDTestCase(test.TestCase):
+                                return_value=dynamic_total):
+             result = self.driver._get_pool_stats()
+         client.cluster.mon_command.assert_has_calls([
+-            mock.call('{"prefix":"df", "format":"json"}', ''),
++            mock.call('{"prefix":"df", "format":"json"}', b''),
+             mock.call('{"prefix":"osd pool get-quota", "pool": "rbd",'
+-                      ' "format":"json"}', ''),
++                      ' "format":"json"}', b''),
+         ])
+         self.assertEqual((free_capacity, total_capacity), result)
+ 
+@@ -1603,9 +1603,9 @@ class RBDTestCase(test.TestCase):
+         ]
+         result = self.driver._get_pool_stats()
+         client.cluster.mon_command.assert_has_calls([
+-            mock.call('{"prefix":"df", "format":"json"}', ''),
++            mock.call('{"prefix":"df", "format":"json"}', b''),
+             mock.call('{"prefix":"osd pool get-quota", "pool": "rbd",'
+-                      ' "format":"json"}', ''),
++                      ' "format":"json"}', b''),
+         ])
+         free_capacity = 1.56
+         total_capacity = 3.0
+diff --git a/cinder/volume/drivers/rbd.py b/cinder/volume/drivers/rbd.py
+index 2fa2e01..8637a61 100644
+--- a/cinder/volume/drivers/rbd.py
++++ b/cinder/volume/drivers/rbd.py
+@@ -546,14 +546,14 @@ class RBDDriver(driver.CloneableImageVD, driver.MigrateVD,
+ 
+         with RADOSClient(self) as client:
+             ret, df_outbuf, __ = client.cluster.mon_command(
+-                '{"prefix":"df", "format":"json"}', '')
++                '{"prefix":"df", "format":"json"}', b'')
+             if ret:
+                 LOG.warning('Unable to get rados pool stats.')
+                 return 'unknown', 'unknown'
+ 
+             ret, quota_outbuf, __ = client.cluster.mon_command(
+                 '{"prefix":"osd pool get-quota", "pool": "%s",'
+-                ' "format":"json"}' % pool_name, '')
++                ' "format":"json"}' % pool_name, b'')
+             if ret:
+                 LOG.warning('Unable to get rados pool quotas.')
+                 return 'unknown', 'unknown'
+-- 
+2.33.0
+
diff --git a/openstack-cinder.spec b/openstack-cinder.spec
index 5ed50aa8440921ad9a38c22dea0d337eda54f5a7..da3a4891772f8b87be90fa997c24f5a1031c8767 100644
--- a/openstack-cinder.spec
+++ b/openstack-cinder.spec
@@ -6,7 +6,7 @@ access block storage volumes for use by Virtual Machine instances.
 
 Name:             openstack-%{service}
 Version:          15.6.0
-Release:          1
+Release:          2
 Summary:          OpenStack Volume service
 License:          ASL 2.0
 URL:              http://www.openstack.org/software/openstack-storage/
@@ -21,6 +21,7 @@ Source13:         openstack-%{service}-backup.service
 
 Source20:         %{service}-sudoers
 Source21:         %{service}.logrotate
+Patch:            0001-RBD-Pass-bytes-type-for-mon_command-inbuf.patch
 
 BuildRequires:         openstack-macros
 BuildRequires:         python3-os-win
@@ -256,8 +257,9 @@ Requires:       python3-%{service}
 This package contains the Cinder test files.
 
 %prep
-%autosetup -n %{service}-%{version}
+%setup -q -n %{service}-%{version}
 %py_req_cleanup
+%autopatch -p1
 
 %build
 %{py3_build}
@@ -377,5 +379,8 @@ exit 0
 %{python3_sitelib}/%{service}/tests
 
 %changelog
+* Wed Mar 16 2022 zhangy1317 <zhangy1317@chinaunicom.cn> - 15.6.0-2
+- Fix RBD: Pass bytes type for mon_command inbuf
+
 * Fri Nov 05 2021 wangxiyuan <wangxiyuan1007@gmail.com> - 15.6.0-1
 - Support OpenStack Train release