add --nohints option

The command will not use the hints file to locate devices for PVs.
It will still do standard hint file invalidation where appropriate.

test/shell/hints.sh

@@ -37,6 +37,57 @@ aux prepare_devs 6
 pvs
 not grep scan: $HINTS
 
+#
+# test --nohints option
+#
+
+pvcreate "$dev1"
+pvcreate "$dev2"
+# pvs --nohints does not create hints
+pvs --nohints |tee out
+grep "$dev1" out
+grep "$dev2" out
+not grep "$dev1" $HINTS
+not grep "$dev2" $HINTS
+# pvs creates hints
+pvs
+grep "$dev1" $HINTS
+grep "$dev2" $HINTS
+
+# save hints with dev1 and dev2 before dev3 is created
+cp $HINTS $PREV
+# pvcreate --nohints invalidates hints
+pvcreate --nohints "$dev3"
+ls $NEWHINTS
+# pvs --nohints does not update hints
+pvs --nohints |tee out
+grep "$dev1" out
+grep "$dev2" out
+grep "$dev3" out
+not grep "$dev3" $HINTS
+# restore old hint file without dev3
+cp $PREV $HINTS
+# pvs --nohints does not update hints
+pvs --nohints |tee out
+grep "$dev1" out
+grep "$dev2" out
+grep "$dev3" out
+grep "$dev1" $HINTS
+grep "$dev2" $HINTS
+not grep "$dev3" $HINTS
+# pvs updates hints
+pvs |tee out
+grep "$dev1" out
+grep "$dev2" out
+grep "$dev3" out
+grep "$dev1" $HINTS
+grep "$dev2" $HINTS
+grep "$dev3" $HINTS
+
+aux wipefs_a "$dev1"
+aux wipefs_a "$dev2"
+aux wipefs_a "$dev3"
+
 #
 # vg1 uses dev1,dev2
 #
@@ -44,6 +95,8 @@ not grep scan: $HINTS
 # and that only PVs are scanned when using hints.
 #
 
+rm $HINTS
+
 vgcreate $vg1 "$dev1" "$dev2"
 lvcreate -n $lv1 -l 4 $vg1
 

tools/args.h

@@ -460,6 +460,11 @@ arg(noheadings_ARG, '\0', "noheadings", 0, 0, 0,
     "Suppress the headings line that is normally the first line of output.\n"
     "Useful if grepping the output.\n")
 
+arg(nohints_ARG, '\0', "nohints", 0, 0, 0,
+    "Do not use the hints file to locate devices for PVs. A command may read\n"
+    "more devices to find PVs when hints are not used. The command will still\n"
+    "perform standard hint file invalidation where appropriate.\n")
+
 arg(nohistory_ARG, '\0', "nohistory", 0, 0, 0,
     "Do not record history of LVs being removed.\n"
     "This has no effect unless the configuration setting\n"

tools/command-lines.in

@@ -204,7 +204,7 @@
 #
 OO_ALL: --commandprofile String, --config String, --debug,
 --driverloaded Bool, --help, --nolocking, --lockopt String, --longhelp, --profile String, --quiet,
---verbose, --version, --yes, --test, --devicesfile String, --devices PV
+--verbose, --version, --yes, --test, --devicesfile String, --devices PV, --nohints
 
 #
 # options for pvs, lvs, vgs, fullreport

tools/lvmcmdline.c

@@ -2512,6 +2512,14 @@ static int _get_current_settings(struct cmd_context *cmd)
 	if (arg_is_set(cmd, sysinit_ARG))
 		cmd->use_hints = 0;
 
+	/*
+	 * Don't use hints from this command, but enable_hints will
+	 * remain set unless hints=none in the config.  See above re
+	 * the meaning of use_hints=0 && enable_hints=1.
+	 */
+	if (arg_is_set(cmd, nohints_ARG))
+		cmd->use_hints = 0;
+
 	if ((hint_mode = find_config_tree_str(cmd, devices_hints_CFG, NULL))) {
 		if (!strcmp(hint_mode, "none")) {
 			cmd->enable_hints = 0;