conf: add metadata/check_pv_device_sizes

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.141 - 
 ====================================
+  Add metadata/check_pv_device_sizes switch to lvm.conf for device size checks.
   Warn if device size is less than corresponding PV size in metadata.
   Cache device sizes internally.
   Restore support for command breaking in process_each_lv_in_vg() (2.02.118).

conf/example.conf.in

@@ -1415,6 +1415,17 @@ activation {
 # This configuration section has an automatic default value.
 # metadata {
 
+	# Configuration option metadata/check_pv_device_sizes.
+	# Check device sizes are not smaller than corresponding PV sizes.
+	# If device size is less than corresponding PV size found in metadata,
+	# there is always a risk of data loss. If this option is set, then LVM
+	# issues a warning message each time it finds that the device size is
+	# less than corresponding PV size. You should not disable this unless
+	# you are absolutely sure about what you are doing!
+	# This configuration option is advanced.
+	# This configuration option has an automatic default value.
+	# check_pv_device_sizes = 1
+
 	# Configuration option metadata/pvmetadatacopies.
 	# Number of copies of metadata to store on each PV.
 	# The --pvmetadatacopies option overrides this setting.

lib/commands/toolcontext.c

@@ -670,6 +670,8 @@ static int _process_config(struct cmd_context *cmd)
 	/* LVM stores sizes internally in units of 512-byte sectors. */
 	init_pv_min_size((uint64_t)pv_min_kb * (1024 >> SECTOR_SHIFT));
 
+	cmd->check_pv_dev_sizes = find_config_tree_bool(cmd, metadata_check_pv_device_sizes_CFG, NULL);
+
 	if (!process_profilable_config(cmd))
 		return_0;
 

lib/commands/toolcontext.h

@@ -113,6 +113,7 @@ struct cmd_context {
 	 * Switches.
 	 */
 	unsigned is_long_lived:1;		/* optimises persistent_filter handling */
+	unsigned check_pv_dev_sizes:1;
 	unsigned handles_missing_pvs:1;
 	unsigned handles_unknown_segments:1;
 	unsigned use_linear_target:1;

lib/config/config_settings.h

@@ -1352,6 +1352,14 @@ cfg_array(activation_auto_lock_start_list_CFG, "auto_lock_start_list", activatio
 	"Locking is auto-started only for VGs selected by this list.\n"
 	"The rules are the same as those for auto_activation_volume_list.\n")
 
+cfg(metadata_check_pv_device_sizes_CFG, "check_pv_device_sizes", metadata_CFG_SECTION, CFG_ADVANCED | CFG_DEFAULT_COMMENTED, CFG_TYPE_BOOL, 1, vsn(2, 2, 141), NULL, 0, NULL,
+	"Check device sizes are not smaller than corresponding PV sizes.\n"
+	"If device size is less than corresponding PV size found in metadata,\n"
+	"there is always a risk of data loss. If this option is set, then LVM\n"
+	"issues a warning message each time it finds that the device size is\n"
+	"less than corresponding PV size. You should not disable this unless\n"
+	"you are absolutely sure about what you are doing!\n")
+
 cfg(metadata_pvmetadatacopies_CFG, "pvmetadatacopies", metadata_CFG_SECTION, CFG_ADVANCED | CFG_DEFAULT_COMMENTED, CFG_TYPE_INT, DEFAULT_PVMETADATACOPIES, vsn(1, 0, 0), NULL, 0, NULL,
 	"Number of copies of metadata to store on each PV.\n"
 	"The --pvmetadatacopies option overrides this setting.\n"

lib/metadata/metadata.c

@@ -672,7 +672,8 @@ static int _check_pv_dev_sizes(struct volume_group *vg)
 	uint64_t dev_size, size;
 	int r = 1;
 
-	if (is_orphan_vg(vg->name))
+	if (!vg->cmd->check_pv_dev_sizes ||
+	    is_orphan_vg(vg->name))
 		return 1;
 
 	dm_list_iterate_items(pvl, &vg->pvs) {