dm thin: log info when growing the data or metadata device

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 35d2e41..2346960 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -2216,6 +2216,10 @@
 		return -EINVAL;
 
 	} else if (data_size > sb_data_size) {
+		if (sb_data_size)
+			DMINFO("%s: growing the data device from %llu to %llu blocks",
+			       dm_device_name(pool->pool_md),
+			       sb_data_size, (unsigned long long)data_size);
 		r = dm_pool_resize_data_dev(pool->pmd, data_size);
 		if (r) {
 			metadata_operation_failed(pool, "dm_pool_resize_data_dev", r);
@@ -2253,6 +2257,9 @@
 		return -EINVAL;
 
 	} else if (metadata_dev_size > sb_metadata_dev_size) {
+		DMINFO("%s: growing the metadata device from %llu to %llu blocks",
+		       dm_device_name(pool->pool_md),
+		       sb_metadata_dev_size, metadata_dev_size);
 		r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size);
 		if (r) {
 			metadata_operation_failed(pool, "dm_pool_resize_metadata_dev", r);