From 88796a8936ca99f8eb03a483a02ee6b62139a60e Mon Sep 17 00:00:00 2001
From: Dmitry Tantsur <dtantsur@protonmail.com>
Date: Wed, 7 Aug 2019 16:10:51 +0200
Subject: [PATCH] Do not try to use zRAM devices for anything

These devices are mapped into memory, but nonetheless can appear
in lsblk output. Ignore them explicitly.

Change-Id: I2bb595ef29abdc98bd887bdf41c3c7f64cc3a7e6
---
 ironic_python_agent/hardware.py                  | 6 ++++++
 ironic_python_agent/tests/unit/test_hardware.py  | 3 ++-
 releasenotes/notes/no-zram-78cc6583f4f90a9c.yaml | 4 ++++
 3 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 releasenotes/notes/no-zram-78cc6583f4f90a9c.yaml

diff --git a/ironic_python_agent/hardware.py b/ironic_python_agent/hardware.py
index 25cfada9c..7c0636be7 100644
--- a/ironic_python_agent/hardware.py
+++ b/ironic_python_agent/hardware.py
@@ -305,6 +305,12 @@ def list_all_block_devices(block_type='disk',
             raise errors.BlockDeviceError(
                 '%s must be returned by lsblk.' % ', '.join(sorted(missing)))
 
+        # NOTE(dtantsur): zRAM devices can appear in the output of lsblk, but
+        # we cannot do anything useful with them.
+        if device['KNAME'].startswith('zram'):
+            LOG.debug('Skipping zRAM device %s', device)
+            continue
+
         name = os.path.join('/dev', device['KNAME'])
 
         try:
diff --git a/ironic_python_agent/tests/unit/test_hardware.py b/ironic_python_agent/tests/unit/test_hardware.py
index 64258757c..2822962cd 100644
--- a/ironic_python_agent/tests/unit/test_hardware.py
+++ b/ironic_python_agent/tests/unit/test_hardware.py
@@ -137,7 +137,8 @@ BLK_DEVICE_TEMPLATE = (
     ' ROTA="0" TYPE="disk"\n'
     'KNAME="sdd" MODEL="NWD-BLP4-1600   " SIZE="1765517033472" '
     ' ROTA="0" TYPE="disk"\n'
-    'KNAME="loop0" MODEL="" SIZE="109109248" ROTA="1" TYPE="loop"'
+    'KNAME="loop0" MODEL="" SIZE="109109248" ROTA="1" TYPE="loop"\n'
+    'KNAME="zram0" MODEL="" SIZE="" ROTA="0" TYPE="disk"'
 )
 
 # NOTE(pas-ha) largest device is 1 byte smaller than 4GiB
diff --git a/releasenotes/notes/no-zram-78cc6583f4f90a9c.yaml b/releasenotes/notes/no-zram-78cc6583f4f90a9c.yaml
new file mode 100644
index 000000000..12597f6d8
--- /dev/null
+++ b/releasenotes/notes/no-zram-78cc6583f4f90a9c.yaml
@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    No longer tries to use zRAM devices for anything.