Reviewing https://review.whamcloud.com/#/c/29818/ I noticed that errors are not being propagated to changelog readers. I suggest that crs_err be changed to int and the errno associated to any errors encountered be stored there. Then this value can be used in chlg_read() if no records were emitted. Also the return value of chld_load() will also be the return value of kthread_stop() in chlg_release(). clhg_release() should save and return any errors there too.