Re: Access Beyond End of Device & Input/Output Errors

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2021/2/20 下午8:07, chainofflowers wrote:
> On 20.02.21 12:46, Forza wrote:
>
>> Are you using fstrim by any chance? Could the problem be related to
>> https://patchwork.kernel.org/project/fstests/patch/20200730121735.55389-1-wqu@suse.com/
>
> Yes, that's what I mentioned in my first post.
> Actually, it all started with the bug with dm, but some similar
> behaviour persists even after that bug was fixed:
> https://lore.kernel.org/linux-btrfs/20190521190023.GA68070@glet/T/
>
> The only "maybe unusual" thing in my setup is that I use btrfs on the
> top of dmcrypt directly, without lvm in-between, but I am not the only
> one...
>
> @Qu:
> My RAM looks OK so far, I also thought of that, and I actually ran
> memtest for 12+ hours and more than once. I would exclude that case.
>
> I will do a "btrfs check --check-data-csum" and let you know.
>
> In the meantime, I thought of a related question:
> -> When a data-csum is corrupted (for whatever reason), is there a
> chance that the corruption persists when I copy the whole file system
> over to a new one?

You can rule out the possibility that some data checksum itself is
corrupted.
Data checksum is stored in btrfs trees, and all tree blocks have their
own checksum.

>
> As I said previously, I copied the whole fs to new, virgin SSDs more
> than once with "rsync -avAHX", and I couldn't spot any issue related to
> the copy itself...

Then you can rule out the checksum problem.

Thanks,
Qu
>
> (please help! ;-))
>
> (c)
>