Re: [PATCH v1 3/5] dpkg: Remove unmount loop

[Jan Kiszka <jan.kiszka@siemens.com>]

On 07.07.21 18:38, Anton Mikanovich wrote:
> Remove while loop when trying to unmount WORKDIR. Any failures of
> umount should be investigated to fix the root cause.
> Also make dpkg_undo_mounts do not fail if dpkg_do_mounts was not
> called or it was called twice.
> 

This is very likely wrong: We know from the past (should be in the git
history, e.g 17d0842d) that not all subprocesses started inside the
chroot may have been terminated when we left it. That can cause
significant delays between returning from chroot and finding non-busy
mount points to complete all umounts. Now, if you silently fail umounts,
you may find inconsistently mounted chroots on the next recipe that
tries to remount them. Big fat warning sign...!

Jan

> Signed-off-by: Anton Mikanovich <amikan@ilbers.de>
> ---
>  meta/classes/dpkg-base.bbclass | 15 +++++----------
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/meta/classes/dpkg-base.bbclass b/meta/classes/dpkg-base.bbclass
> index 97661a6..6c84f3a 100644
> --- a/meta/classes/dpkg-base.bbclass
> +++ b/meta/classes/dpkg-base.bbclass
> @@ -154,16 +154,11 @@ dpkg_do_mounts() {
>  }
>  
>  dpkg_undo_mounts() {
> -    i=1
> -    while ! sudo umount ${BUILDROOT}; do
> -        sleep 0.1
> -        i=`expr $i + 1`
> -        if [ $i -gt 100 ]; then
> -            bbwarn "${BUILDROOT}: Couldn't unmount, retrying..."
> -            i=1
> -        fi
> -    done
> -    sudo rmdir ${BUILDROOT}
> +    buildchroot_undo_mounts
> +
> +    mountpoint -q '${BUILDROOT}' && \
> +        sudo umount ${BUILDROOT} && \
> +        sudo rmdir ${BUILDROOT} || true
>  }
>  
>  # Placeholder for actual dpkg_runbuild() implementation
> 

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