> > I also wanted to run either overlay xfstests or unionmount-testsuite. But > > none of these seem to give me enough flexibility where I can specify > > that overlayfs needs to be mounted on top of virtiofs. > > > > I feel that atleast for unionmount-testsuite, there should be an > > option where we can simply give a target directory and tests run > > on that directory and user mounts that directory as needed. > > > > Need to see how patches look. > Don't want too much configuration complexity, but I agree that some > flexibly is needed. > Maybe the provided target directory should be the upper/work basedir? > Vivek, I was going to see what's the best way to add the needed flexibility, but then I realized I had already implemented this undocumented feature. I have been using this to test overlay over XFS as documented here: https://github.com/amir73il/overlayfs/wiki/Overlayfs-testing#Setup_overlayfs_mount_over_XFS_with_reflink_support That's an example of how to configure a custom /base mount for --samefs to be xfs. Similar hidden feature exists for configuring a custom /lower and /upper mounts via fstab, but I don't think I ever tested those, so not sure if they work as expected. unionmount testsuite will first try to mount the entry from fstab and fallback to mounting tmpfs. I admit this a lousy configuration method, but we could make it official using env vars or something. I also never liked the fact that unionmount testsuite hard codes the /lower /upper /mnt paths. The reason we 'need' the instructions how to mount the fs as opposed to an already mounted dir is that unmounting the underlying fs exposes dentry/inode reference leaks by overlayfs. But it is nice to have and xfstests has support for configuring an already mounted overlayfs for the generic tests. So if you think that you cannot use the existing hack and that pointing to an already mounted /upper or mounted overlay is needed, I suggest that you experiment with patches to make that change. Thanks, Amir.
