cache: capture missing policy name

Policy name has to be always defined.
Capture it as an internal error before write.
When reading metadata without defined policy name, use default defined policy.

TODO: Unsure, but it might have to be actually always 'mq' in this case.

1 files changed, 12 insertions, 4 deletions

diff --git a/lib/cache_segtype/cache.c b/lib/cache_segtype/cache.c
index ca30495aa..ad356a97f 100644
--- a/lib/cache_segtype/cache.c
+++ b/lib/cache_segtype/cache.c
@@ -77,9 +77,13 @@ static int _cache_pool_text_import(struct lv_segment *seg,
 			return SEG_LOG_ERROR("policy must be a string in");
 		if (!(seg->policy_name = dm_pool_strdup(mem, str)))
 			return SEG_LOG_ERROR("Failed to duplicate policy in");
-	} else
+	} else {
 		/* Cannot use 'just' default, so pick one */
 		seg->policy_name = DEFAULT_CACHE_POOL_POLICY; /* FIXME make configurable */
+		/* FIXME maybe here should be always 'mq' */
+		log_warn("WARNING: cache_policy undefined, using default \"%s\" policy.",
+			 seg->policy_name);
+	}
 
 	/*
 	 * Read in policy args:
@@ -130,13 +134,17 @@ static int _cache_pool_text_export(const struct lv_segment *seg,
 	if (!(cache_mode = get_cache_pool_cachemode_name(seg)))
 		return_0;
 
+	if (!seg->policy_name) {
+		log_error(INTERNAL_ERROR "Policy name for %s is not defined.",
+			  display_lvname(seg->lv));
+		return 0;
+	}
+
 	outf(f, "data = \"%s\"", seg_lv(seg, 0)->name);
 	outf(f, "metadata = \"%s\"", seg->metadata_lv->name);
 	outf(f, "chunk_size = %" PRIu32, seg->chunk_size);
 	outf(f, "cache_mode = \"%s\"", cache_mode);
-
-	if (seg->policy_name)
-		outf(f, "policy = \"%s\"", seg->policy_name);
+	outf(f, "policy = \"%s\"", seg->policy_name);
 
 	if (seg->policy_settings) {
 		if (strcmp(seg->policy_settings->key, "policy_settings")) {