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Merged
vojtechtrefny merged 1 commit into from
Jun 3, 2025
Merged

lvm: Add support for running vgcfgbackup/restore #1109

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2 changes: 2 additions & 0 deletions docs/libblockdev-sections.txt
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Expand Up @@ -327,6 +327,8 @@ bd_lvm_vgextend
bd_lvm_vgreduce
bd_lvm_vglock_start
bd_lvm_vglock_stop
bd_lvm_vgcfgbackup
bd_lvm_vgcfgrestore
bd_lvm_add_vg_tags
bd_lvm_delete_vg_tags
bd_lvm_vginfo
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37 changes: 37 additions & 0 deletions src/lib/plugin_apis/lvm.api
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Expand Up @@ -738,6 +738,7 @@ typedef enum {
BD_LVM_TECH_DEVICES,
BD_LVM_TECH_SHARED,
BD_LVM_TECH_CONFIG,
BD_LVM_TECH_VG_CFG_BACKUP_RESTORE,
} BDLVMTech;

typedef enum {
Expand Down Expand Up @@ -2044,4 +2045,40 @@ gboolean bd_lvm_devices_delete (const gchar *device, const gchar *devices_file,
*/
gchar* bd_lvm_config_get (const gchar *section, const gchar *setting, const gchar *type, gboolean values_only, gboolean global_config, const BDExtraArg **extra, GError **error);

/**
* bd_lvm_vgcfgbackup:
* @vg_name: name of the VG to backup configuration
* @backup_file: (nullable): file to save the backup to or %NULL for using the default backup file
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@tbzatek tbzatek May 30, 2025

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I still get an impression that this is about backing up the whole VG data. I think it should be noted this is about configuration of the VG.

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@vojtechtrefny vojtechtrefny May 31, 2025

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Ok, I've changed both the docstrings to emphasize the backup/restore is for configuration only. I've also added note from the vgcfgbackup which mentions this doesn't back up the LV data.

* in /etc/lvm/backup
* @extra: (nullable) (array zero-terminated=1): extra options for the vgcfgbackup command
* (just passed to LVM as is)
* @error: (out) (optional): place to store error (if any)
*
* Note: This function does not back up the data content of LVs. See `vgcfbackup(8)` man page
* for more information.
*
* Returns: Whether the backup was successfully created or not.
*
* Tech category: %BD_LVM_TECH_VG_CFG_BACKUP_RESTORE no mode (it is ignored)
*/
gboolean bd_lvm_vgcfgbackup (const gchar *vg_name, const gchar *backup_file, const BDExtraArg **extra, GError **error);

/**
* bd_lvm_vgcfgrestore:
* @vg_name: name of the VG to restore configuration
* @backup_file: (nullable): file to restore VG configuration from to or %NULL for using the
* latest backup in /etc/lvm/backup
* @extra: (nullable) (array zero-terminated=1): extra options for the vgcfgrestore command
* (just passed to LVM as is)
* @error: (out) (optional): place to store error (if any)
*
* Note: This function restores VG configuration created by %bd_lvm_vgcfgbackup from given
* @backup_file or from the latest backup in /etc/lvm/backup.
*
* Returns: Whether the configuration was successfully restored or not.
*
* Tech category: %BD_LVM_TECH_VG_CFG_BACKUP_RESTORE no mode (it is ignored)
*/
gboolean bd_lvm_vgcfgrestore (const gchar *vg_name, const gchar *backup_file, const BDExtraArg **extra, GError **error);

#endif /* BD_LVM_API */
63 changes: 63 additions & 0 deletions src/plugins/lvm/lvm-common.c
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Expand Up @@ -787,3 +787,66 @@ gchar* bd_lvm_config_get (const gchar *section, const gchar *setting, const gcha
return NULL;
return g_strchomp (output);
}

gboolean _vgcfgbackup_restore (const gchar *command, const gchar *vg_name, const gchar *file, const BDExtraArg **extra, GError **error) {
const gchar *args[6] = {"lvm", NULL, NULL, NULL, NULL, NULL};
guint next_arg = 1;
gchar *output = NULL;
g_autofree gchar *config_arg = NULL;

args[next_arg++] = command;
if (file) {
args[next_arg++] = "-f";
args[next_arg++] = file;
}
args[next_arg++] = vg_name;

g_mutex_lock (&global_config_lock);
if (global_config_str) {
config_arg = g_strdup_printf ("--config=%s", global_config_str);
args[next_arg++] = config_arg;
}
g_mutex_unlock (&global_config_lock);

return bd_utils_exec_and_capture_output (args, extra, &output, error);
}

/**
* bd_lvm_vgcfgbackup:
* @vg_name: name of the VG to backup configuration
* @backup_file: (nullable): file to save the backup to or %NULL for using the default backup file
* in /etc/lvm/backup
* @extra: (nullable) (array zero-terminated=1): extra options for the vgcfgbackup command
* (just passed to LVM as is)
* @error: (out) (optional): place to store error (if any)
*
* Note: This function does not back up the data content of LVs. See `vgcfbackup(8)` man page
* for more information.
*
* Returns: Whether the backup was successfully created or not.
*
* Tech category: %BD_LVM_TECH_VG_CFG_BACKUP_RESTORE no mode (it is ignored)
*/
gboolean bd_lvm_vgcfgbackup (const gchar *vg_name, const gchar *backup_file, const BDExtraArg **extra, GError **error) {
return _vgcfgbackup_restore ("vgcfgbackup", vg_name, backup_file, extra, error);
}

/**
* bd_lvm_vgcfgrestore:
* @vg_name: name of the VG to restore configuration
* @backup_file: (nullable): file to restore VG configuration from to or %NULL for using the
* latest backup in /etc/lvm/backup
* @extra: (nullable) (array zero-terminated=1): extra options for the vgcfgrestore command
* (just passed to LVM as is)
* @error: (out) (optional): place to store error (if any)
*
* Note: This function restores VG configuration created by %bd_lvm_vgcfgbackup from given
* @backup_file or from the latest backup in /etc/lvm/backup.
*
* Returns: Whether the configuration was successfully restored or not.
*
* Tech category: %BD_LVM_TECH_VG_CFG_BACKUP_RESTORE no mode (it is ignored)
*/
gboolean bd_lvm_vgcfgrestore (const gchar *vg_name, const gchar *backup_file, const BDExtraArg **extra, GError **error) {
return _vgcfgbackup_restore ("vgcfgrestore", vg_name, backup_file, extra, error);
}
2 changes: 2 additions & 0 deletions src/plugins/lvm/lvm-dbus.c
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Expand Up @@ -382,6 +382,8 @@ gboolean bd_lvm_is_tech_avail (BDLVMTech tech, guint64 mode, GError **error) {
return check_deps (&avail_deps, DEPS_LVMDEVICES_MASK, deps, DEPS_LAST, &deps_check_lock, error);
case BD_LVM_TECH_CONFIG:
return check_deps (&avail_deps, DEPS_LVMCONFIG_MASK, deps, DEPS_LAST, &deps_check_lock, error);
case BD_LVM_TECH_VG_CFG_BACKUP_RESTORE:
return check_deps (&avail_deps, DEPS_LVM_MASK, deps, DEPS_LAST, &deps_check_lock, error);
default:
/* everything is supported by this implementation of the plugin */
return check_dbus_deps (&avail_dbus_deps, DBUS_DEPS_LVMDBUSD_MASK, dbus_deps, DBUS_DEPS_LAST, &deps_check_lock, error);
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3 changes: 3 additions & 0 deletions src/plugins/lvm/lvm.h
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Expand Up @@ -202,6 +202,7 @@ typedef enum {
BD_LVM_TECH_DEVICES,
BD_LVM_TECH_SHARED,
BD_LVM_TECH_CONFIG,
BD_LVM_TECH_VG_CFG_BACKUP_RESTORE,
} BDLVMTech;

typedef enum {
Expand Down Expand Up @@ -256,6 +257,8 @@ gboolean bd_lvm_add_vg_tags (const gchar *vg_name, const gchar **tags, GError **
gboolean bd_lvm_delete_vg_tags (const gchar *vg_name, const gchar **tags, GError **error);
gboolean bd_lvm_vglock_start (const gchar *vg_name, const BDExtraArg **extra, GError **error);
gboolean bd_lvm_vglock_stop (const gchar *vg_name, const BDExtraArg **extra, GError **error);
gboolean bd_lvm_vgcfgbackup (const gchar *vg_name, const gchar *backup_file, const BDExtraArg **extra, GError **error);
gboolean bd_lvm_vgcfgrestore (const gchar *vg_name, const gchar *backup_file, const BDExtraArg **extra, GError **error);
BDLVMVGdata* bd_lvm_vginfo (const gchar *vg_name, GError **error);
BDLVMVGdata** bd_lvm_vgs (GError **error);

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31 changes: 31 additions & 0 deletions tests/lvm_dbus_tests.py
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Expand Up @@ -6,6 +6,7 @@
import re
import shutil
import time
import tempfile
from contextlib import contextmanager
from packaging.version import Version
from itertools import chain
Expand Down Expand Up @@ -2404,3 +2405,33 @@ def test_set_empty_config(self):
BlockDev.lvm_set_global_config("")
succ = BlockDev.lvm_pvremove(self.loop_dev)
self.assertTrue(succ)


class LvmTestBackupRestore(LvmPVVGTestCase):
def test_vgcfgbackup_restore(self):
"""Verify that it is possible to backup and restore VG configuration"""

succ = BlockDev.lvm_pvcreate(self.loop_dev, 0, 0, None)
self.assertTrue(succ)

succ = BlockDev.lvm_vgcreate("testVG", [self.loop_dev], 0, None)
self.assertTrue(succ)

with tempfile.TemporaryDirectory() as d:
succ = BlockDev.lvm_vgcfgbackup("testVG", os.path.join(d, "testVGbackup"))
self.assertTrue(succ)
self.assertTrue(os.path.isfile(os.path.join(d, "testVGbackup")))

succ = BlockDev.lvm_vgcfgrestore("testVG", os.path.join(d, "testVGbackup"))
self.assertTrue(succ)

succ = BlockDev.lvm_vgcfgbackup("testVG", None)
self.assertTrue(succ)

# default location is /etc/lvm/backup/<vgname>
self.assertTrue(os.path.isfile("/etc/lvm/backup/testVG"))

succ = BlockDev.lvm_vgcfgrestore("testVG", None)
self.assertTrue(succ)

os.unlink("/etc/lvm/backup/testVG")
31 changes: 31 additions & 0 deletions tests/lvm_test.py
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Expand Up @@ -5,6 +5,7 @@
import overrides_hack
import re
import shutil
import tempfile
import time
from contextlib import contextmanager
from packaging.version import Version
Expand Down Expand Up @@ -2291,3 +2292,33 @@ def test_set_empty_config(self):
BlockDev.lvm_set_global_config("")
succ = BlockDev.lvm_pvremove(self.loop_dev)
self.assertTrue(succ)


class LvmTestBackupRestore(LvmPVVGTestCase):
def test_vgcfgbackup_restore(self):
"""Verify that it is possible to backup and restore VG configuration"""

succ = BlockDev.lvm_pvcreate(self.loop_dev, 0, 0, None)
self.assertTrue(succ)

succ = BlockDev.lvm_vgcreate("testVG", [self.loop_dev], 0, None)
self.assertTrue(succ)

with tempfile.TemporaryDirectory() as d:
succ = BlockDev.lvm_vgcfgbackup("testVG", os.path.join(d, "testVGbackup"))
self.assertTrue(succ)
self.assertTrue(os.path.isfile(os.path.join(d, "testVGbackup")))

succ = BlockDev.lvm_vgcfgrestore("testVG", os.path.join(d, "testVGbackup"))
self.assertTrue(succ)

succ = BlockDev.lvm_vgcfgbackup("testVG", None)
self.assertTrue(succ)

# default location is /etc/lvm/backup/<vgname>
self.assertTrue(os.path.isfile("/etc/lvm/backup/testVG"))

succ = BlockDev.lvm_vgcfgrestore("testVG", None)
self.assertTrue(succ)

os.unlink("/etc/lvm/backup/testVG")