[elbe-devel] [PATCH 2/4] finetuning: set_partition_type: ignore reread ptable error

[Bastian Germann]

Am 29.03.21 um 13:03 schrieb Torben Hohn:
> When fdisk writes a new partition table, it tries to make the
> kernel reread it. This does not work for loop devices and
> makes fdisk return a non-zero return code.
> 
> -----------------------------------------------------------------------------------------------------------------------------
> [CMD] losetup --find --show --partscan "/var/cache/elbe/4f553e2f-e976-426d-8c40-69cfe5ad47fd/sda.img"
> [CMD] fdisk /dev/loop0
> 
> Welcome to fdisk (util-linux 2.33.1).
> Changes will remain in memory only, until you decide to write them.
> Be careful before using the write command.
> 
> Command (m for help): Partition number (1,2, default 2): Hex code (type L to list all codes):
> Changed type of partition 'Linux' to 'Hidden FAT16 <32M'.
> 
> Command (m for help): The partition table has been altered.
> Calling ioctl() to re-read partition table.
> Re-reading the partition table failed.: Device or resource busy
> 
> The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8).
> 
> [CMD] losetup --detach "/dev/loop0"
> [ERROR] ProjectFinetuning Error, trying to continue anyways
> Traceback (most recent call last):
>    File "/var/cache/elbe/devel/elbepack/finetuning.py", line 790, in do_prj_finetuning
>      action.execute_prj(buildenv, target, builddir)
>    File "/var/cache/elbe/devel/elbepack/finetuning.py", line 559, in execute_prj
>      action.execute_img(buildenv, target, builddir, loop_dev)
>    File "/var/cache/elbe/devel/elbepack/finetuning.py", line 716, in execute_img
>      do(cmd, stdin=inp)
>    File "/var/cache/elbe/devel/elbepack/shellhelper.py", line 258, in do
>      raise CommandError(cmd, p.returncode)
> elbepack.shellhelper.CommandError: Error: 1 returned from Command fdisk /dev/loop0
> -----------------------------------------------------------------------------------------------------------------------------
> 
> However, the next thing elbe does, is clear the loop mount and
> the partition layout was not changed anyways. So this error
> can be safely ignored.
> 
> Ignore it.
> 
> Signed-off-by: Torben Hohn <torben.hohn at linutronix.de>
> ---
>   elbepack/finetuning.py | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/elbepack/finetuning.py b/elbepack/finetuning.py
> index 16d07ea8c..d3968bb68 100644
> --- a/elbepack/finetuning.py
> +++ b/elbepack/finetuning.py
> @@ -713,7 +713,15 @@ class SetPartitionTypeAction(ImageFinetuningAction):
>           cmd = f'fdisk {loop_dev}'
>           inp = f't\n{part_nr}\n{part_type}\nw\n'
>   
> -        do(cmd, stdin=inp)
> +        try:
> +            do(cmd, stdin=inp)
> +        except CommandError as e:
> +            # At the end, fdisk tries to reread the partitiontable
> +            # and fails. This makes it return 1.

Is this the only error case that exits as 1? I do not think so.

> +            #
> +            # When it returns 1, we can just continue.
> +            if e.returncode != 1:
> +                raise
>   
>   
>   @FinetuningAction.register("unit-tests")
>