[Fedora-livecd-list] [PATCH] Don't truncate the overlay file on a reset.

[Frederick Grose]

On Wed, Aug 29, 2012 at 9:15 PM, Frederick Grose <fgrose at gmail.com> wrote:
> commit d0d4f29cdd0a0e6dd1170965decb282ef5511746
> Author: Frederick Grose <fgrose at sugarlabs.org>
> Date:   Wed Aug 29 21:02:07 2012 -0400
>
>     Don't truncate the overlay file on a reset.
>
> diff --git a/modules.d/90dmsquash-live/dmsquash-live-root.sh
> b/modules.d/90dmsquash-live/dmsquash-live-root.sh
> index f8bfca6..62340a5 100755
> --- a/modules.d/90dmsquash-live/dmsquash-live-root.sh
> +++ b/modules.d/90dmsquash-live/dmsquash-live-root.sh
> @@ -98,7 +98,7 @@ do_live_overlay() {
>          if [ -f /run/initramfs/overlayfs$pathspec -a -w
> /run/initramfs/overlayfs$pathspec ]; then
>              losetup $OVERLAY_LOOPDEV /run/initramfs/overlayfs$pathspec
>              if [ -n "$reset_overlay" ]; then
> -                dd if=/dev/zero of=$OVERLAY_LOOPDEV bs=64k count=1 2>/dev/null
> +                dd if=/dev/zero of=$OVERLAY_LOOPDEV bs=64k count=1
> conv=notrunc 2>/dev/null
>              fi
>              setup="yes"
>          fi

Void the above patch.

I don't know why the overlay is NOT truncated without the notrunc
conversion argument to dd.

However, my testing shows that this bug is fixed by using the fsync
conversion argument,
https://bugzilla.redhat.com/show_bug.cgi?id=832884

A revised patch file is attached to the bug ticket.

        --Fred