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

[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
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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.
+            #
+            # When it returns 1, we can just continue.
+            if e.returncode != 1:
+                raise
 
 
 @FinetuningAction.register("unit-tests")
-- 
2.20.1