On Wed, Oct 26, 2016 at 2:26 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > ... > > BTW I don't remember having tested this, so it might possibly be > buggy. Automatic multi-layer testing would really be good. What we > basically need is: > > - create normal (two layer) overlay (with interesting constructs, > whiteout, opaque dir, redirect) > - umount > - create three layer overlay where the two lower layers come from the > previous upper/lower layers > - do more interesting things > > There's one such test in xfstests but it would be good to have more. > I have a POC for generic addition of layers for unionmount-testsuite I pushed it to my github: https://github.com/amir73il/unionmount-testsuite.git #ovl_rename_dir remount(ctx) rotates upper to top of lower layers and adds a new upper layer For now, remount(ctx) is called after successful mkdir and rename dir to catch directory redirect bugs. As it happens, it is very easy to find a bug, because it is enough to just umount an mount the overlay without even adding a new layer after directory rename to corrupt the overlayfs lookup. Almost every rename-*-dir test demonstrates the problem Going forward, I intend to hook the remount(ctx) event in a cleaner way, so for every VFS op in every subtest, it is possible to configure a test where the operation happens: - without any remount - with umount + mount - with umount + mount with a new layer Cheers, Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
