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

[Gerardo Exequiel Pozzi]

On 02/22/2012 04:39 AM, Dieter Plaetinck wrote:
> 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
>
Yes, --read-only loops.

-- 
Gerardo Exequiel Pozzi
\cos^2\alpha + \sin^2\alpha = 1