Re: [f2fs-dev] [PATCH 2/2] f2fs: relocate chksum_offset for large_nat_bitmap feature

[Chao Yu]

Hi Ju Hyung,

On 2019/4/24 19:43, Ju Hyung Park wrote:
> Hi Chao,
> 
> On Mon, Apr 22, 2019 at 6:34 PM Chao Yu <yuchao0@xxxxxxxxxx> wrote:
>> +       if (__is_set_ckpt_flags(*cp_block, CP_LARGE_NAT_BITMAP_FLAG)) {
>> +               if (crc_offset != CP_MIN_CHKSUM_OFFSET) {
>> +                       f2fs_put_page(*cp_page, 1);
>> +                       f2fs_msg(sbi->sb, KERN_WARNING,
>> +                               "layout of large_nat_bitmap is deprecated, "
>> +                               "run fsck to repair, chksum_offset: %zu",
>> +                               crc_offset);
>> +                       return -EINVAL;
>> +               }
>> +       }
>> +
> 
> I try not to be a Grammar Nazi and a jerk on every patches, but since
> this is a message a user would directly encounter, I'd like to see a
> bit less ambiguous message.

Please feel free to give us your opinion or suggestion. :)

> 
> How about "using deprecated layout of large_nat_bitmap, please run
> fsck v1.13.0 or higher to repair, chksum_offset: %zu"?
> The original message seems to suggest that large_nat_bitmap is
> deprecated outright.
> 
> Also, I'd like to suggest to write down an actual version of
> f2fs-tools here as we've seen older versions of fsck doing even more
> damage and the users might not have the latest f2fs-tools installed.

Agreed, user should be told which version of fsck can repair that problem, will
update the message in next version.

> 
> Btw, what happens if we use the latest fsck to fix the corrupted image
> and use the older kernel to mount it?
> Would it even mount?

No, since fixed image is using a new layout, how about giving the detailed
information about which version of kernel user should update to, once we detect
such issue and trigger the repairing?

Thanks,

> 
> Thanks.
> .
>