lib-storage: Rotate dovecot.list.index.log* more often.

The history in these files isn't as important as in mailbox indexes.
Reduce disk space usage by rotating them more often and deleting the
.log.2 more quickly.

src/lib-storage/list/mailbox-list-index.c

@@ -12,6 +12,12 @@
 
 #define MAILBOX_LIST_INDEX_REFRESH_DELAY_MSECS 1000
 
+/* dovecot.list.index.log doesn't have to be kept for that long. */
+#define MAILBOX_LIST_INDEX_LOG_ROTATE_MIN_SIZE (8*1024)
+#define MAILBOX_LIST_INDEX_LOG_ROTATE_MAX_SIZE (64*1024)
+#define MAILBOX_LIST_INDEX_LOG_ROTATE_SECS_AGO (5*60)
+#define MAILBOX_LIST_INDEX_LOG2_STALE_SECS (10*60)
+
 static void mailbox_list_index_init_finish(struct mailbox_list *list);
 
 struct mailbox_list_index_module mailbox_list_index_module =
@@ -73,6 +79,11 @@ int mailbox_list_index_index_open(struct mailbox_list *list)
 	mail_index_set_permissions(ilist->index, perm.file_create_mode,
 				   perm.file_create_gid,
 				   perm.file_create_gid_origin);
+	mail_index_set_log_rotation(ilist->index,
+				    MAILBOX_LIST_INDEX_LOG_ROTATE_MIN_SIZE,
+				    MAILBOX_LIST_INDEX_LOG_ROTATE_MAX_SIZE,
+				    MAILBOX_LIST_INDEX_LOG_ROTATE_SECS_AGO,
+				    MAILBOX_LIST_INDEX_LOG2_STALE_SECS);
 
 	mail_index_set_fsync_mode(ilist->index, set->parsed_fsync_mode, 0);
 	mail_index_set_lock_method(ilist->index, set->parsed_lock_method,