Re: [f2fs-dev] [PATCH 4/5] f2fs: get rid of stale fault injection code

[Yufen Yu]

Hi,

On 2022/4/1 16:28, Chao Yu wrote:
> On 2022/4/1 15:19, Yufen Yu via Linux-f2fs-devel wrote:
> > Nowly, we can use new fault injection framework. Just delete the
> > stale fault injection code.
> >
> > Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
> > ---
> >   fs/f2fs/checkpoint.c |  2 +-
> >   fs/f2fs/f2fs.h       | 51 ++----------------------------------------
> >   fs/f2fs/super.c      | 53 --------------------------------------------
> >   fs/f2fs/sysfs.c      | 23 -------------------
> >   4 files changed, 3 insertions(+), 126 deletions(-)

...

> >               break;
> > @@ -1963,14 +1920,6 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> >       if (F2FS_IO_SIZE_BITS(sbi))
> >           seq_printf(seq, ",io_bits=%u",
> >                   F2FS_OPTION(sbi).write_io_size_bits);
> > -#ifdef CONFIG_F2FS_FAULT_INJECTION
> > -    if (test_opt(sbi, FAULT_INJECTION)) {
> > -        seq_printf(seq, ",fault_injection=%u",
> > -                F2FS_OPTION(sbi).fault_info.inject_rate);
> > -        seq_printf(seq, ",fault_type=%u",
> > -                F2FS_OPTION(sbi).fault_info.inject_type);
> > -    }
> > -#endif
>
> This will cause regression due to it breaks application usage w/ -o
> fault_* mountoption..., I don't think this is the right way.


Thanks for catching this. I admit it's a problem. But, IMO fault_* mount
option are mostly been used in test, not in actual product. So, I think
it may just affect some test applications. With the common fault injection
framework, it can be more easy and flexible to do fault injection test.
Therefore, I want to remove the two mount options directly.

If you really worried about compatibility, how about just reserving the
two inject_* options but without doing any thing for them. We actually
configure fault injections by debugfs in this patch.

Or do you have more better suggestion?

Thanks,
Yufen