on-going issues on overlayfs in Linux kernel

As of 2016-02-11, the following issues are critical known bugs about overlayfs in Linux kernel.

• (overlayfs) moving a file to a directory that exists only in `upper` and deleting it creates unnecessary whiteout file

  • https://bugzilla.kernel.org/show_bug.cgi?id=109611
  • solution #1: “ovl: ignore lower entries when checking purity of non-directory entries”
  • solution #2-1: “ovl: Do not leave whiteout during unlink/rmdir if parent does not have merge property”
  • solution #2-2: “overlay: Clear stale ->numlower state over rename operation”
  • “overlayfs: Can’t delete file moved from base layer to newly created dir even on ext4”

• overlayfs whiteout files appearing within container

  • : possibly related to the issue above

• Overlayfs on top of btrfs causes kernel oops + freeze

  • https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg47032.html
  • https://github.com/coreos/bugs/issues/1110
  • https://github.com/coreos/rkt/issues/1498

• tar command fails with OverlayFS storage driver but not with aufs

• vfs: update atime using file->f_inode

  • : This fixes some cases of missing atime update for overlayfs

• ovl: copy new uid/gid into overlayfs runtime inode

• ovl: copy MS_POSIXACL flag from upper layer

• ovl: fix working on distributed fs as lower layer

• ovl: detect distributed fs also by looking into default dentry operations