Re: corrupt leaf, unexpected item end, unmountable

[Daniel Dawson <danielcdawson@gmail.com>]

On 2/18/21 3:57 PM, Chris Murphy wrote:
> metadata raid6 as well?

Yes.

> What replacement command(s) are you using?

For this drive, it was "btrfs replace start -r 3 /dev/sda3 /"

> What device is devid 3? 
It would normally be sdc3. I'll address the confusion below.
> 16315=0x3fbb, 16283=0x3f9b, 16315^16283 = 32 or 0x20
> 11111110111011
> 11111110011011
>         ^
>
> Do a RAM test for as long as you can tolerate it, or it finds the
> defect. Sometimes they show up quickly, other times days.
I didn't think of a flipped bit. Thanks.
>>         devid    0 size 457.64GiB used 39.53GiB path /dev/sdc3
>>         devid    1 size 457.64GiB used 39.56GiB path /dev/sda3
>>         devid    2 size 457.64GiB used 39.56GiB path /dev/sdb3
>>         devid    4 size 457.64GiB used 39.53GiB path /dev/sdd3
>
> This is confusing. devid 3 is claimed to be missing, but fi show isn't
> showing any missing devices. If none of sd[abcd] are devid 3, then
> what dev node is devid 3 and where is it?
It looks to me like btrfs is temporarily assigning devid 0 to the new
device being used as a replacement. That is what I observed before; once
the replace operation was complete, it went back to the normal number.
Since the replacement didn't finish this time, sdc3 is still devid 0.
> But yeah you're probably best off not trying to fix this file system
> until the memory is sorted out.
Right. I'll get on that soon and see if anything pops up. Thanks for the
help so far.