Hi Mark, Arnd,
We've stumbled onto a statx/ext2-related kernel bug.
The bug itself isn't that interesting, but we were confused why we only
saw it on arm64 (arm32, x86, x86_64 did not see it).
It turns out, the bug is in EXT2 (not in the EXT4 compatibility
implementation, but actual EXT2) as a result of arm64 defconfig
including EXT2_FS, which isn't included in arm multi_v7_defconfig nor
x86's defconfigs.
This surprised us a bit, and so we're wondering if EXT2_FS should be
removed from arm64 defconfig?
See https://bugs.linaro.org/show_bug.cgi?id=4012 for details.
Dan