From 517f17481685afbabea6750b57d71a736f9a157e Mon Sep 17 00:00:00 2001

From: Vojtech Trefny <vtrefny@redhat.com>

Date: Thu, 25 May 2023 17:02:39 +0200

Subject: [PATCH] Do not add new PVs to the LVM devices file if it doesn't

 exist and VGs are present

If there is a preexisting VG on the system when we create a new PV

and the LVM devices file doesn't exist we will create it and add

only the new PV to it which means the preexisting VG will now be

ignored by LVM tools. This change skips adding newly created PVs

to the devices file in the same way 'pvcreate' and 'vgcreate' do.

---

 blivet/devicelibs/lvm.py                     |  3 +

 blivet/formats/lvmpv.py                      | 17 ++++-

 tests/unit_tests/formats_tests/__init__.py   |  1 +

 tests/unit_tests/formats_tests/lvmpv_test.py | 73 ++++++++++++++++++++

 4 files changed, 91 insertions(+), 3 deletions(-)

 create mode 100644 tests/unit_tests/formats_tests/lvmpv_test.py

diff --git a/blivet/devicelibs/lvm.py b/blivet/devicelibs/lvm.py

index 16a8e8f8..dc7d0cbe 100644

--- a/blivet/devicelibs/lvm.py

+++ b/blivet/devicelibs/lvm.py

@@ -84,6 +84,9 @@ if hasattr(blockdev.LVMTech, "DEVICES"):

 else:

     HAVE_LVMDEVICES = False

+

+LVM_DEVICES_FILE = "/etc/lvm/devices/system.devices"

+

 # list of devices that LVM is allowed to use

 # with LVM >= 2.0.13 we'll use this for the --devices option and when creating

 # the /etc/lvm/devices/system.devices file

diff --git a/blivet/formats/lvmpv.py b/blivet/formats/lvmpv.py

index cb01b2f3..65acedbe 100644

--- a/blivet/formats/lvmpv.py

+++ b/blivet/formats/lvmpv.py

@@ -36,7 +36,7 @@ from ..size import Size

 from ..errors import PhysicalVolumeError

 from . import DeviceFormat, register_device_format

 from .. import udev

-from ..static_data.lvm_info import pvs_info

+from ..static_data.lvm_info import pvs_info, vgs_info

 import logging

 log = logging.getLogger("blivet")

@@ -121,10 +121,21 @@ class LVMPhysicalVolume(DeviceFormat):

     def supported(self):

         return super(LVMPhysicalVolume, self).supported and self._plugin.available

-    def lvmdevices_add(self):

+    def lvmdevices_add(self, force=True):

+        """ Add this PV to the LVM system devices file

+            :keyword force: whether to add the PV even if the system devices file doesn't exist and

+                            VGs are present in the system

+            :type force: bool

+        """

+

         if not lvm.HAVE_LVMDEVICES:

             raise PhysicalVolumeError("LVM devices file feature is not supported")

+        if not os.path.exists(lvm.LVM_DEVICES_FILE) and vgs_info.cache and not force:

+            log.debug("Not adding %s to devices file: %s doesn't exist and there are VGs present in the system",

+                      self.device, lvm.LVM_DEVICES_FILE)

+            return

+

         try:

             blockdev.lvm.devices_add(self.device)

         except blockdev.LVMError as e:

@@ -151,7 +162,7 @@ class LVMPhysicalVolume(DeviceFormat):

                 # with lvmdbusd we need to call the pvcreate without --devices otherwise lvmdbusd

                 # wouldn't be able to find the newly created pv and the call would fail

                 blockdev.lvm.pvcreate(self.device, data_alignment=self.data_alignment, extra=[ea_yes])

-                self.lvmdevices_add()

+                self.lvmdevices_add(force=False)

         else:

             blockdev.lvm.pvcreate(self.device, data_alignment=self.data_alignment, extra=[ea_yes])

diff --git a/tests/unit_tests/formats_tests/__init__.py b/tests/unit_tests/formats_tests/__init__.py

index d678900b..95c7a25b 100644

--- a/tests/unit_tests/formats_tests/__init__.py

+++ b/tests/unit_tests/formats_tests/__init__.py

@@ -2,6 +2,7 @@ from .device_test import *

 from .disklabel_test import *

 from .init_test import *

 from .luks_test import *

+from .lvmpv_test import *

 from .methods_test import *

 from .misc_test import *

 from .selinux_test import *

diff --git a/tests/unit_tests/formats_tests/lvmpv_test.py b/tests/unit_tests/formats_tests/lvmpv_test.py

new file mode 100644

index 00000000..6490c7d4

--- /dev/null

+++ b/tests/unit_tests/formats_tests/lvmpv_test.py

@@ -0,0 +1,73 @@

+try:

+    from unittest.mock import patch

+except ImportError:

+    from mock import patch

+

+from contextlib import contextmanager

+

+import unittest

+

+from blivet.formats.lvmpv import LVMPhysicalVolume

+

+

+class LVMPVNodevTestCase(unittest.TestCase):

+

+    @contextmanager

+    def patches(self):

+        patchers = dict()

+        mocks = dict()

+

+        patchers["blockdev"] = patch("blivet.formats.lvmpv.blockdev")

+        patchers["lvm"] = patch("blivet.formats.lvmpv.lvm")

+        patchers["vgs_info"] = patch("blivet.formats.lvmpv.vgs_info")

+        patchers["os"] = patch("blivet.formats.lvmpv.os")

+

+        for name, patcher in patchers.items():

+            mocks[name] = patcher.start()

+

+        yield mocks

+

+        for patcher in patchers.values():

+            patcher.stop()

+

+    def test_lvm_devices(self):

+        fmt = LVMPhysicalVolume(device="/dev/test")

+

+        with self.patches() as mock:

+            # LVM devices file not enabled/supported -> devices_add should not be called

+            mock["lvm"].HAVE_LVMDEVICES = False

+

+            fmt._create()

+

+            mock["blockdev"].lvm.devices_add.assert_not_called()

+

+        with self.patches() as mock:

+            # LVM devices file enabled and devices file exists -> devices_add should be called

+            mock["lvm"].HAVE_LVMDEVICES = True

+            mock["os"].path.exists.return_value = True

+

+            fmt._create()

+

+            mock["blockdev"].lvm.devices_add.assert_called_with("/dev/test")

+

+        with self.patches() as mock:

+            # LVM devices file enabled and devices file doesn't exist

+            # and no existing VGs present -> devices_add should be called

+            mock["lvm"].HAVE_LVMDEVICES = True

+            mock["os"].path.exists.return_value = False

+            mock["vgs_info"].cache = {}

+

+            fmt._create()

+

+            mock["blockdev"].lvm.devices_add.assert_called_with("/dev/test")

+

+        with self.patches() as mock:

+            # LVM devices file enabled and devices file doesn't exist

+            # and existing VGs present -> devices_add should not be called

+            mock["lvm"].HAVE_LVMDEVICES = True

+            mock["os"].path.exists.return_value = False

+            mock["vgs_info"].cache = {"fake_vg_uuid": "fake_vg_data"}

+

+            fmt._create()

+

+            mock["blockdev"].lvm.devices_add.assert_not_called()

-- 

2.43.0