[nrf fromlist] settings: zms: code style clean up

Clean some parts of the code and refactor it to avoid multiple nested
conditions

Upstream PR #: 87792

Signed-off-by: Riadh Ghaddab <[email protected]>
(cherry picked from commit a11a6114156690aa3271193ca05f1210c8686ec2)

Author: rghaddab

subsys/settings/src/settings_zms.c

@@ -254,7 +254,8 @@ static int settings_zms_load_subtree(struct settings_store *cs, const struct set
 		ret = settings_call_set_handler(arg->subtree, rc2, settings_zms_read_fn,
 						&read_fn_arg, (void *)arg);
 		/* We should return here as there are no need to look for the next
-		 * hash collision */
+		 * hash collision
+		 */
 		return ret;
 	}
 
@@ -660,6 +661,44 @@ static ssize_t settings_zms_get_val_len(struct settings_store *cs, const char *n
 	return 0;
 }
 
+/* This function inits the linked list head if it doesn't exist or recover it
+ * if the ll_last_hash_id is different than the head hash ID
+ */
+static int settings_zms_init_or_recover_ll(struct settings_zms *cf, uint32_t ll_last_hash_id)
+{
+	struct settings_hash_linked_list settings_element;
+	int rc = 0;
+
+	if (ll_last_hash_id == ZMS_LL_HEAD_HASH_ID) {
+		/* header doesn't exist */
+		settings_element.previous_hash = 0;
+		settings_element.next_hash = 0;
+		rc = zms_write(&cf->cf_zms, ZMS_LL_HEAD_HASH_ID, &settings_element,
+			       sizeof(struct settings_hash_linked_list));
+		if (rc < 0) {
+			return rc;
+		}
+		cf->last_hash_id = ZMS_LL_HEAD_HASH_ID;
+		cf->second_to_last_hash_id = 0;
+#ifdef CONFIG_SETTINGS_ZMS_LL_CACHE
+		/* store the LL header in cache */
+		cf->ll_cache_next = 0;
+		cf->ll_cache[cf->ll_cache_next++] = settings_element;
+#endif
+	} else {
+		/* let's recover it by keeping all nodes until the last one */
+		settings_element.previous_hash = cf->second_to_last_hash_id;
+		settings_element.next_hash = 0;
+		rc = zms_write(&cf->cf_zms, cf->last_hash_id, &settings_element,
+			       sizeof(struct settings_hash_linked_list));
+		if (rc < 0) {
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
 static int settings_zms_get_last_hash_ids(struct settings_zms *cf)
 {
 	struct settings_hash_linked_list settings_element;
@@ -679,34 +718,7 @@ static int settings_zms_get_last_hash_ids(struct settings_zms *cf)
 			/* header doesn't exist or linked list broken, reinitialize the header
 			 * if it doesn't exist and recover it if it is broken
 			 */
-			if (ll_last_hash_id == ZMS_LL_HEAD_HASH_ID) {
-				/* header doesn't exist */
-				const struct settings_hash_linked_list settings_element = {
-					.previous_hash = 0, .next_hash = 0};
-				rc = zms_write(&cf->cf_zms, ZMS_LL_HEAD_HASH_ID, &settings_element,
-					       sizeof(struct settings_hash_linked_list));
-				if (rc < 0) {
-					return rc;
-				}
-				cf->last_hash_id = ZMS_LL_HEAD_HASH_ID;
-				cf->second_to_last_hash_id = 0;
-#ifdef CONFIG_SETTINGS_ZMS_LL_CACHE
-				/* store the LL header in cache */
-				cf->ll_cache_next = 0;
-				cf->ll_cache[cf->ll_cache_next++] = settings_element;
-#endif
-			} else {
-				/* let's recover it by keeping all nodes until the last one */
-				const struct settings_hash_linked_list settings_element = {
-					.previous_hash = cf->second_to_last_hash_id,
-					.next_hash = 0};
-				rc = zms_write(&cf->cf_zms, cf->last_hash_id, &settings_element,
-					       sizeof(struct settings_hash_linked_list));
-				if (rc < 0) {
-					return rc;
-				}
-			}
-			return 0;
+			return settings_zms_init_or_recover_ll(cf, ll_last_hash_id);
 		} else if (rc < 0) {
 			return rc;
 		}