Re: [PATCH v3 1/1] expand-on-first-boot: wait for udev to create symlink

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

On 09.12.22 12:24, T. Schaffner wrote:
> From: Tobias Schaffner <tobias.schaffner@siemens.com>
> 
> systemd-growfs depends on a symlink to the partition of the filesystem
> that should be resized. This symlink is created by udev in /dev/block/.
> 
> If this symlink is not yet created for example because systemd-udev is
> not up yet systemd-growfs will fail.
> 
> We could use Require and After to depend on the systemd-udev service
> but this could again create a race condition if udev is up but not
> fast enough after the partx -u.
> 
> Run systemd-growfs periodically until the symlink appears.
> 
> Signed-off-by: Tobias Schaffner <tobias.schaffner@siemens.com>
> ---
>  .../files/expand-last-partition.sh            | 21 ++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
> index 57055cc..4d78e4f 100755
> --- a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
> +++ b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
> @@ -80,6 +80,25 @@ if [ ! -d "${MOUNT_POINT}" ]; then
>  fi
>  
>  mount "${LAST_PART}" "${MOUNT_POINT}"
> -/lib/systemd/systemd-growfs "${MOUNT_POINT}"
> +
> +EXIT_CODE=1
> +# If systemd-udevd if not up yet or was not fast enough the symlinks in
> +# /dev/block/ might be missing. Retry in that case.
> +# This retry logic is only needed up to systemd-version 252
> +for run in $(seq 0 50); do
> +    if GROWFS_OUTPUT=$(/lib/systemd/systemd-growfs "${MOUNT_POINT}" 2>&1); then
> +        EXIT_CODE=0
> +        break
> +    else:
          ^^^
?

And why else at all? You break the loop anyway.

Jan

> +        if ! echo ${GROWFS_OUTPUT} | grep -q "^Failed to open \"/dev/block/.*\": No such file or directory$"; then
> +            break
> +        fi
> +    fi
> +    sleep 0.1
> +done
> +
> +echo "${GROWFS_OUTPUT}"
>  umount "${MOUNT_POINT}"
>  rmdir "${MOUNT_POINT}"
> +exit ${EXIT_CODE}
> +

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