"btrfs send" returns "Inappropriate ioctl for device"

[Rolf Leggewie]

It seems I discovered another "Inappropriate ioctl for device" bug when running an amd64 kernel on an i386 system (the first one was bug 1619918). My system is trusty, but I assume later versions and even upstream are affected.

Steps to reproduce:
- run an amd64 kernel via multi-arch on an i386 system
- Try to "btrfs send" or "btrfs receive" a subvolume

Result:
$ sudo btrfs send /mnt/LTS/snapshots/home-daily-2017-03-16/ -f /tmp/home-daily-2017-03-16.btrfs
At subvol /mnt/LTS/snapshots/home-daily-2017-03-16/
ERROR: send ioctl failed with -25: Inappropriate ioctl for device

This occurs with 3.13.0-96-generic as well as 3.13.0-114-generic (which fixes bug 1619918).

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1678645

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Rolf Leggewie (r0lf)]

There's nothing missing, all necessary information is there.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1678645

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.11 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.11-rc5

[Rolf Leggewie (r0lf)]

FWIW, this affects for example the latest www.system-rescue-cd.org as well dated 2nd of April. It boots by default into an amd64 kernel but the btrfs tools are i386. Very much looks like an upstream issue to me and possibly more relevant than one might be tempted to think initially.