lvmdevices check: error exit if update is needed

. error exit means that lvmdevices --update would make a change.

. remove check of PART field from --check because it isn't used.

. unlink searched_devnames file to ensure check|update will search

lib/device/device_id.c

@@ -2278,6 +2278,7 @@ void device_ids_find_renamed_devs(struct cmd_context *cmd, struct dm_list *dev_l
 			continue;
 		}
 
+		if (!noupdate)
 			log_warn("Devices file PVID %s updating IDNAME to %s.", dev->pvid, devname);
 
 		free(du->idname);

test/shell/devicesfile-realdevs.sh

@@ -423,7 +423,7 @@ sed "s/$pvid1/badpvid/" "$DF.orig" |tee $DF
 not grep $pvid1 $DF
 grep $did1 $DF
 
-lvmdevices --check 2>&1|tee out
+not lvmdevices --check 2>&1|tee out
 grep $dev1 out
 grep badpvid out
 grep $pvid1 out
@@ -493,7 +493,7 @@ rm $DF
 d1=$(basename $dev1)
 d3=$(basename $dev3)
 sed "s/$d1/$d3/" "$DF.orig" |tee $DF
-lvmdevices --check 2>&1 |tee out
+not lvmdevices --check 2>&1 |tee out
 grep $dev1 out
 
 lvmdevices --update
@@ -515,7 +515,7 @@ sed "s/$d1/tmp/" "$DF.orig" |tee ${DF}_1
 sed "s/$d2/$d1/" "${DF}_1" |tee ${DF}_2
 sed "s/tmp/$d2/" "${DF}_2" |tee $DF
 rm ${DF}_1 ${DF}_2
-lvmdevices --check 2>&1 |tee out
+not lvmdevices --check 2>&1 |tee out
 grep $dev1 out
 grep $dev2 out
 
@@ -536,7 +536,7 @@ rm $DF
 d1=$(basename $dev1)
 d3=$(basename $dev3)
 sed "s/$d1/$d3/" "$DF.orig" |tee $DF
-lvmdevices --check 2>&1 |tee out
+not lvmdevices --check 2>&1 |tee out
 grep $dev1 out
 
 pvs -o+uuid,deviceid | grep $vg |tee out

tools/args.h

@@ -159,7 +159,8 @@ arg(cachesize_ARG, '\0', "cachesize", sizemb_VAL, 0, 0,
     "The size of cache to use.\n")
 
 arg(check_ARG, '\0', "check", 0, 0, 0,
-    "Check the content of the devices file.\n")
+    "Checks the content of the devices file.\n"
+    "Reports incorrect device names or PVIDs for entries.\n")
 
 arg(commandprofile_ARG, '\0', "commandprofile", string_VAL, 0, 0,
     "The command profile to use for command configuration.\n"

tools/lvmdevices.c

@@ -128,7 +128,6 @@ int lvmdevices(struct cmd_context *cmd, int argc, char **argv)
 	struct device *dev;
 	struct dev_use *du, *du2;
 	const char *deviceidtype;
-	int changes = 0;
 
 	dm_list_init(&search_pvids);
 	dm_list_init(&found_devs);
@@ -184,8 +183,11 @@ int lvmdevices(struct cmd_context *cmd, int argc, char **argv)
 
 	if (arg_is_set(cmd, check_ARG) || arg_is_set(cmd, update_ARG)) {
 		int search_count = 0;
+		int update_needed = 0;
 		int invalid = 0;
 
+		unlink_searched_devnames(cmd);
+
 		label_scan_setup_bcache();
 
 		dm_list_iterate_items(du, &cmd->use_devices) {
@@ -225,6 +227,8 @@ int lvmdevices(struct cmd_context *cmd, int argc, char **argv)
 		 * run just above.
 		 */
 		device_ids_validate(cmd, NULL, &invalid, 1);
+		if (invalid)
+			update_needed = 1;
 
 		/*
 		 * Find and fix any devname entries that have moved to a
@@ -240,33 +244,24 @@ int lvmdevices(struct cmd_context *cmd, int argc, char **argv)
 				label_scan_invalidate(du->dev);
 		}
 
-		/*
-		 * check du->part
-		 */
-		dm_list_iterate_items(du, &cmd->use_devices) {
-			int part = 0;
-			if (!du->dev)
-				continue;
-			dev = du->dev;
-
-			dev_get_partition_number(dev, &part);
-
-			if (part != du->part) {
-				log_warn("Device %s partition %u has incorrect PART in devices file (%u)",
-					 dev_name(dev), part, du->part);
-				du->part = part;
-				changes++;
-			}
-		}
-
 		if (arg_is_set(cmd, update_ARG)) {
-			if (invalid || !dm_list_empty(&found_devs)) {
+			if (update_needed || !dm_list_empty(&found_devs)) {
 				if (!device_ids_write(cmd))
 					goto_bad;
 				log_print("Updated devices file to version %s", devices_file_version());
 			} else {
 				log_print("No update for devices file is needed.");
 			}
+		} else {
+			/*
+			 * --check exits with an error if the devices file
+			 * needs updates, i.e. running --update would make
+			 * changes.
+			 */
+			if (update_needed) {
+				log_error("Updates needed for devices file.");
+				goto bad;
+			}
 		}
 		goto out;
 	}