[arch-releng] [RFC] [PATCH] [archiso] Make a list of used block devices

[Dieter Plaetinck]

On Tue, 21 Feb 2012 20:01:30 -0300
Gerardo Exequiel Pozzi <vmlinuz386 at yahoo.com.ar> wrote:

> NOTE: Not tested yet, but should work(tm).
> 
> This list includes block devices of ( /run/archiso/used_block_devices ):
> * Boot medium [archisodevice] (only if no copytoram= is used)
> * Loop medium [img_dev] (only if no copytoram= is used)
> * COW space [cowdevice] (only if cowdevice= is used (no tmpfs is used))
> * Loop devices used for SquashFS images.
> * Loop devices used for device-mapper devices (two per each dm-device, one RO{*.fs} and one RW{*.cow})
> 
> Aditionally all loop devices except for backing COW files, all are setup as read-only.
> 
> In configs/releng profile, a symlink is made at boot-time for AIF:
> /run/aif/ignore_devs -> /run/archiso/used_block_devices
> ---
>  archiso/hooks/archiso                              |   20 ++++++++++++++++----
>  archiso/hooks/archiso_loop_mnt                     |    3 ++-
>  .../rc.d/functions.d/symlink_used_block_devices    |    7 +++++++
>  3 files changed, 25 insertions(+), 5 deletions(-)
>  create mode 100644 configs/releng/root-image/etc/rc.d/functions.d/symlink_used_block_devices
> 
> diff --git a/archiso/hooks/archiso b/archiso/hooks/archiso
> index 3518d16..22b67e9 100644
> --- a/archiso/hooks/archiso
> +++ b/archiso/hooks/archiso
> @@ -10,7 +10,8 @@ _mnt_fs() {
>  
>      mkdir -p "${newroot}${mnt}"
>  
> -    ro_dev=$(losetup --find --show "${img}")
> +    ro_dev=$(losetup --find --show --read-only "${img}")
> +    echo ${ro_dev} >> /run/archiso/used_block_devices
>      ro_dev_size=$(blockdev --getsz ${ro_dev})
>  
>      if [[ "${cow_persistent}" == "P" ]]; then
> @@ -30,6 +31,7 @@ _mnt_fs() {
>      fi
>  
>      rw_dev=$(losetup --find --show "/run/archiso/cowspace/${cow_directory}/${img_name}.cow")
> +    echo ${rw_dev} >> /run/archiso/used_block_devices
>  
>      echo "0 ${ro_dev_size} snapshot ${ro_dev} ${rw_dev} ${cow_persistent} 8" | dmsetup create ${dm_snap_name}
>  
> @@ -39,6 +41,7 @@ _mnt_fs() {
>          launch_interactive_shell
>      else
>          echo "/dev/mapper/${dm_snap_name} ${mnt} auto defaults 0 0" >> ${newroot}/etc/fstab
> +        echo /dev/mapper/${dm_snap_name} >> /run/archiso/used_block_devices
>      fi
>  }
>  
> @@ -46,7 +49,8 @@ _mnt_fs() {
>  _mnt_sfs() {
>      local img="${1}"
>      local mnt="${2}"
> -    local img_fullname="${img##*/}";
> +    local img_fullname="${img##*/}"
> +    local sfs_dev
>  
>      mkdir -p "${mnt}"
>  
> @@ -60,7 +64,9 @@ _mnt_sfs() {
>          msg "done."
>      fi
>      msg ":: Mounting '${img}' (SquashFS) to '${mnt}'"
> -    if ! mount -r "${img}" "${mnt}" &> /dev/null ; then
> +    sfs_dev=$(losetup --find --show --read-only "${img}")
> +    echo ${sfs_dev} >> /run/archiso/used_block_devices
> +    if ! mount -r "${sfs_dev}" "${mnt}" &> /dev/null ; then
>          echo "ERROR: while mounting '${img}' to '${mnt}'"
>          launch_interactive_shell
>      fi
> @@ -137,7 +143,12 @@ run_hook() {
>  archiso_mount_handler() {
>      local newroot="${1}"
>  
> -    mountpoint -q "/run/archiso/bootmnt" || _mnt_dev "${archisodevice}" "/run/archiso/bootmnt" "-r"
> +    if ! mountpoint -q "/run/archiso/bootmnt"; then
> +        _mnt_dev "${archisodevice}" "/run/archiso/bootmnt" "-r"
> +        if [[ "${copytoram}" != "y" ]]; then
> +            echo $(readlink -f ${archisodevice}) >> /run/archiso/used_block_devices
> +        fi
> +    fi
>  
>      if [[ ! -f "${aitab}" ]]; then
>          echo "ERROR: '${aitab}' file does not exist."
> @@ -170,6 +181,7 @@ archiso_mount_handler() {
>  
>      if [[ -n "${cow_device}" ]]; then
>          _mnt_dev "${cow_device}" "/run/archiso/cowspace" "-r"
> +        echo $(readlink -f ${cow_device}) >> /run/archiso/used_block_devices
>          mount -o remount,rw "/run/archiso/cowspace"
>      else
>          msg ":: Mounting /run/archiso/cowspace (tmpfs) filesystem, size=${cowspace_size}..."
> diff --git a/archiso/hooks/archiso_loop_mnt b/archiso/hooks/archiso_loop_mnt
> index 664f3a5..808100d 100644
> --- a/archiso/hooks/archiso_loop_mnt
> +++ b/archiso/hooks/archiso_loop_mnt
> @@ -15,7 +15,7 @@ archiso_loop_mount_handler () {
>      msg ":: Setup a loop device from ${img_loop} located at device ${img_dev}"
>      _mnt_dev "${img_dev}" "/run/archiso/img_dev" "-r"
>  
> -    if ! _dev_loop=$(losetup --find --show "/run/archiso/img_dev/${img_loop}"); then
> +    if ! _dev_loop=$(losetup --find --show --read-only "/run/archiso/img_dev/${img_loop}"); then
>          echo "ERROR: Setting loopback device for file '/run/archiso/img_dev/${img_loop}'"
>          launch_interactive_shell
>      fi
> @@ -27,5 +27,6 @@ archiso_loop_mount_handler () {
>          umount /run/archiso/img_dev
>      else
>          echo ${_dev_loop} > /run/archiso/img_dev_loop
> +        echo $(readlink -f ${img_dev}) >> /run/archiso/used_block_devices
>      fi
>  }
> diff --git a/configs/releng/root-image/etc/rc.d/functions.d/symlink_used_block_devices b/configs/releng/root-image/etc/rc.d/functions.d/symlink_used_block_devices
> new file mode 100644
> index 0000000..e2b9fc1
> --- /dev/null
> +++ b/configs/releng/root-image/etc/rc.d/functions.d/symlink_used_block_devices
> @@ -0,0 +1,7 @@
> +symlink_used_block_devices()
> +{
> +    mkdir /run/aif
> +    ln -s /run/archiso/used_block_devices /run/aif/ignore_devs
> +}
> +
> +add_hook multi_end symlink_used_block_devices

Hey G,
seems like there's some small edits in here that have nothing to do with the actual block device listing changeset?

Dieter