Re: [LTP] [f2fs] a1e09b03e6: ltp.ADSP024.fail

From: Eric Biggers
Date: Fri Jan 07 2022 - 17:49:13 EST


On Sun, Dec 26, 2021 at 09:28:52PM +0800, kernel test robot wrote:
>
>
> Greeting,
>
> FYI, we noticed the following commit (built with gcc-9):
>
> commit: a1e09b03e6f5c1d713c88259909137c0fd264ede ("f2fs: use iomap for direct I/O")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
>
> in testcase: ltp
> version: ltp-x86_64-14c1f76-1_20211221
> with following parameters:
>
> disk: 1HDD
> fs: f2fs
> test: ltp-aiodio.part2
> ucode: 0x21
>

This is caused by an f2fs bug where it exposes DIO-allocated blocks to users
before they have been initialized. This test actually fails both before and
after my commit "f2fs: use iomap for direct I/O". It is nondeterministic, which
is why it may have appeared to be a regression.

I'll start a separate discussion on linux-f2fs-devel about this, since this
thread has too many irrelevant mailing lists and this has been discussed before.

- Eric