dm verity: allow only one error handling mode

If more than one one handling mode is requested during DM verity table
load, the last requested mode will be used.

Change this to impose more strict checking so that the table load will
fail if more than one error handling mode is requested.

Signed-off-by: JeongHyeon Lee <[e-mail]>
Signed-off-by: Mike Snitzer <[e-mail]>

drivers/md/dm-verity-target.c

···
 	return r;
 }
 
+static inline bool verity_is_verity_mode(const char *arg_name)
+{
+	return (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING) ||
+		!strcasecmp(arg_name, DM_VERITY_OPT_RESTART) ||
+		!strcasecmp(arg_name, DM_VERITY_OPT_PANIC));
+}
+
+static int verity_parse_verity_mode(struct dm_verity *v, const char *arg_name)
+{
+	if (v->mode)
+		return -EINVAL;
+
+	if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING))
+		v->mode = DM_VERITY_MODE_LOGGING;
+	else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART))
+		v->mode = DM_VERITY_MODE_RESTART;
+	else if (!strcasecmp(arg_name, DM_VERITY_OPT_PANIC))
+		v->mode = DM_VERITY_MODE_PANIC;
+
+	return 0;
+}
+
 static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
 				 struct dm_verity_sig_opts *verify_args)
 {
···
 		arg_name = dm_shift_arg(as);
 		argc--;
 
-		if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING)) {
-			v->mode = DM_VERITY_MODE_LOGGING;
-			continue;
-
-		} else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART)) {
-			v->mode = DM_VERITY_MODE_RESTART;
-			continue;
-
-		} else if (!strcasecmp(arg_name, DM_VERITY_OPT_PANIC)) {
-			v->mode = DM_VERITY_MODE_PANIC;
+		if (verity_is_verity_mode(arg_name)) {
+			r = verity_parse_verity_mode(v, arg_name);
+			if (r) {
+				ti->error = "Conflicting error handling parameters";
+				return r;
+			}
 			continue;
 
 		} else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) {
···
 
 static struct target_type verity_target = {
 	.name		= "verity",
-	.version	= {1, 7, 0},
+	.version	= {1, 8, 0},
 	.module		= THIS_MODULE,
 	.ctr		= verity_ctr,
 	.dtr		= verity_dtr,