> I asked this question in last email as well. errseq_sample() will return > 0 if current error has not been seen yet. That means next time a sync > call comes for volatile mount, it will return an error. But that's > not what we want. When we mounted a volatile overlay, if there is an > existing error (seen/unseen), we don't care. We only care if there > is a new error after the volatile mount, right? > > I guess we will need another helper similar to errseq_smaple() which > just returns existing value of errseq. And then we will have to > do something about errseq_check() to not return an error if "since" > and "eseq" differ only by "seen" bit. > > Otherwise in current form, volatile mount will always return error > if upperdir has error and it has not been seen by anybody. > > How did you finally end up testing the error case. Want to simualate > error aritificially and test it. > Good spotting! Besides the specialized test for sync error, I wonder if anybody ever tested "volatile" setup with xfstests or unionmount? In xfsftest can set envvar OVERLAY_MOUNT_OPTIONS="-o volatile" In unionmount I have a branch [1] with support for envvar UNIONMOUNT_MNTOPTIONS. I did not merge this change to master because nobody (but me) tested it, so that would be a good opportunity (hint hint) Thanks, Amir. [1] https://github.com/amir73il/unionmount-testsuite/commits/envvars
