From 3056bbfc2cb24ec80ebfd831bf5c2fb3d7596a2f Mon Sep 17 00:00:00 2001
From: Toomas Soome <tsoome@FreeBSD.org>
Date: Sat, 3 Apr 2021 02:40:51 +0300
Subject: [PATCH] loader: we should support pools without features

nvlist_check_features_for_read() does return error when there
are no features for read.

Reported by:	yuripv

(cherry picked from commit d36341f7b8ddc2457a1e9e4a721d27d2e66cb39a)
---
 stand/libsa/zfs/zfsimpl.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/stand/libsa/zfs/zfsimpl.c b/stand/libsa/zfs/zfsimpl.c
index bc577f16845..7036b508fa3 100644
--- a/stand/libsa/zfs/zfsimpl.c
+++ b/stand/libsa/zfs/zfsimpl.c
@@ -191,8 +191,16 @@ nvlist_check_features_for_read(nvlist_t *nvl)
 
 	rc = nvlist_find(nvl, ZPOOL_CONFIG_FEATURES_FOR_READ,
 	    DATA_TYPE_NVLIST, NULL, &features, NULL);
-	if (rc != 0)
-		return (rc);
+	switch (rc) {
+	case 0:
+		break;		/* Continue with checks */
+
+	case ENOENT:
+		return (0);	/* All features are disabled */
+
+	default:
+		return (rc);	/* Error while reading nvlist */
+	}
 
 	data = (nvs_data_t *)features->nv_data;
 	nvp = &data->nvl_pair;	/* first pair in nvlist */