+int journal_file_set_online(JournalFile *f) {
+ assert(f);
+
+ if (!f->writable)
+ return -EPERM;
+
+ if (!(f->fd >= 0 && f->header))
+ return -EINVAL;
+
+ switch(f->header->state) {
+ case STATE_ONLINE:
+ return 0;
+
+ case STATE_OFFLINE:
+ f->header->state = STATE_ONLINE;
+ fsync(f->fd);
+ return 0;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+int journal_file_set_offline(JournalFile *f) {
+ assert(f);
+
+ if (!f->writable)
+ return -EPERM;
+
+ if (!(f->fd >= 0 && f->header))
+ return -EINVAL;
+
+ if (f->header->state != STATE_ONLINE)
+ return 0;
+
+ fsync(f->fd);
+
+ f->header->state = STATE_OFFLINE;
+
+ fsync(f->fd);
+
+ return 0;
+}
+