• Vivek Goyal's avatar
    ovl: Ensure upper filesystem supports d_type · 45aebeaf
    Vivek Goyal authored
    In some instances xfs has been created with ftype=0 and there if a file
    on lower fs is removed, overlay leaves a whiteout in upper fs but that
    whiteout does not get filtered out and is visible to overlayfs users.
    
    And reason it does not get filtered out because upper filesystem does
    not report file type of whiteout as DT_CHR during iterate_dir().
    
    So it seems to be a requirement that upper filesystem support d_type for
    overlayfs to work properly. Do this check during mount and fail if d_type
    is not supported.
    Suggested-by: default avatarDave Chinner <dchinner@redhat.com>
    Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
    Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
    45aebeaf
overlayfs.h 6.76 KB