WHATS_NEW                  | 1 +

 lib/activate/dev_manager.c | 5 +++++

 2 files changed, 6 insertions(+)

diff --git a/WHATS_NEW b/WHATS_NEW

index d1f4530..00b84f9 100644

--- a/WHATS_NEW

+++ b/WHATS_NEW

@@ -2,6 +2,7 @@ Version 2.02.187 -

 ===================================

   Prevent creating VGs with PVs with different logical block sizes.

   Pvmove runs in exlusively activating mode for exclusively active LVs.

+  Activate thin-pool layered volume as 'read-only' device.

   Enhance validation for thin and cache pool conversion and swapping.

 Version 2.02.186 - 27th August 2019

diff --git a/lib/activate/dev_manager.c b/lib/activate/dev_manager.c

index dc64159..56608e3 100644

--- a/lib/activate/dev_manager.c

+++ b/lib/activate/dev_manager.c

@@ -84,6 +84,11 @@ int read_only_lv(const struct logical_volume *lv, const struct lv_activate_opts

 	if (lv_is_raid_image(lv) || lv_is_raid_metadata(lv))

 		return 0; /* Keep RAID SubLvs writable */

+	if (!layer) {

+		if (lv_is_thin_pool(lv))

+			return 1;

+	}

+

 	return (laopts->read_only || !(lv->status & LVM_WRITE));

 }