Re: Can btrfs repair this ?

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

On 2023/11/6 07:08, Joe Salmeri wrote:
> Hi,
>
> I was running openSUSE Tumbleweed build 20231001 when I first found this
> issue but updated to TW build 20231031 the other day and it still
> reports the same issue.
>
> Kernel 6.5.9-1 btrfsprogs 6.5.1-1.2 Device Samsung 860 EVO 500 GB
> Partion #5 root btrfs filesystem, no RAID or other drives
>
> I run "btrfs device stats /" about once a week and no problems are
> reported.
>
> I run "btrfs scrub start /"   regularly too and no problem are reported
>
> I ran "btrfs check --readonly --force /dev/sda5" the other day and got
> the following errors:
>
>          Opening filesystem to check...
>
>          WARNING: filesystem mounted, continuing because of --force
>          Checking filesystem on /dev/sda5
>          UUID: 7591d83f-f78e-402b-afe5-fab23dad0ffe
>          [1/7] checking root items
>          [2/7] checking extents
>          [3/7] checking free space cache
>          [4/7] checking fs roots
>          root 262 inode 31996735 errors 1, no inode item
>                  unresolved ref dir 132030 index 769 namelen 36 name
> 02179466-b671-4313-8fa5-0eb87d716f92 filetype 2 errors 5, no dir item,
> no inode ref
>                  unresolved ref dir 132030 index 769 namelen 36 name
> 77ef9cd4-0efe-46af-bf7f-47f582851e16 filetype 2 errors 2, no dir index
>          ERROR: errors found in fs roots
>          found 33034690560 bytes used, error(s) found
>          total csum bytes: 28819244
>          total tree bytes: 986251264
>          total fs tree bytes: 876134400
>          total extent tree bytes: 62521344
>          btree space waste bytes: 277302161
>          file data blocks allocated: 141608800256
>           referenced 39054090240
>
> Running "find -inum 31996735" identifies the item is is complaining
> about as
>
>          /usr/bin/find: File system loop detected;
> ‘./.snapshots/1/snapshot’ is part of the same file system loop as ‘.’.
>          /usr/bin/find:
> ‘./home/denise/.config/skypeforlinux/blob_storage/02179466-b671-4313-8fa5-0eb87d716f92’: No such file or directory
>
> Running "ls -al /home/denise/.config/skypeforlinux/blob_storage/" also
> shows that this is correct item
>
>      drwx------ 1 denise joe-denise   72 Nov  1 22:49 .
>      drwxr-xr-x 1 denise joe-denise 3.7K Nov  1 20:07 ..
>      d????????? ? ?      ?             ?            ?
> 02179466-b671-4313-8fa5-0eb87d716f92
>
> When I originally ran btrfs check there were actually a bunch of other
> items listed, however, I have timeline snapshots turned on for the
> /@home subvolume and all the other items were because of that item in
> each of the other snapshots.
>
> I removed all the other "home" snapshots and now btrfs check only
> reports that one item as shown above.
>
> I have heard that btrfs check --repair is generally not recommended but
> I have been unable to find a way to have btrfs remove the item it is
> complaining about.

--repair can fix the problem.

But for your particular problem, please also do a memtest just in case.

This problem looks like a bad hash, which may be caused by memory bitflip.

Thanks,
Qu
>
> I have tried rmdir, rm -rf, as well as find -inum 31996735 -delete and
> all report the same issue with not found.
>
> If I understand correctly, the parent directory entry ( so
> /home/denise/.config/skypeforlinux/blob_storage/ ) has the entry for
> /home/denise/.config/skypeforlinux/blob_storage/02179466-b671-4313-8fa5-0eb87d716f92 with inode of 31996735 but it doesn't really exist.
>
> I do not consider this a HW issue because btrfs stats, scrub, and smart
> do not report any errors and I also track all the smart info ( health,
> reallocated sector, wear leveling, etc ) for SSDs and there are no
> errors reported and I am not having any other issues.
>
> I suspect that this occurred the other day when Skype crashed. The item
> is not needed, I just cannot figure out how to remove it.
>
> So, is it possible for me to remove this item and if so how do I do it ?
>