[Bug 1869281]

[kernel.20.drkshadow]

+1, me too.

Converting one partition (containing a device-mapper container with an ext4 filesystem) to btrfs,
see: btrfs-convert-and-mount.txt

a btrfs-convert -r works fine, fsck after the rollback returns no issue,
the filesystem is mountable and fine. I did this once, with 50GB free
space, and ran into this error. Suspicious that maybe there wasn't
enough free space for the metadata, I freed up 400GB and ran it again -
and this is the output of the second try.

One note may be: I typically create my ext4 filesystems with `-O
sparse_super`.

Including attachments for dump-super, and tree-stats. `btrfs dump-tree`
didn't seem to produce any errors (`grep -i 'error' | grep -iv '\<name:
.*err'` -- lots of files with "error" in the name).

btrfs built with `march=native -O2 -mtune=native` which generally
includes some AVX-512 code.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to btrfs-progs in Ubuntu.
https://bugs.launchpad.net/bugs/1869281

Title:
  btrfs-convert of ext4 yields unmountable FS

Status in Btrfs Tools:
  Confirmed
Status in btrfs-progs package in Ubuntu:
  Confirmed

Bug description:
  This is with btrfs-progs 5.4.1-2 in focal.  Similar result with
  5.2.1-1ubuntu1 in eoan.

  Following conversion, both mount and btrfs check report an extent that
  reached beyond the end of the device:

  ERROR: dev extent devid 1 physical offset 126701535232 len 33554432 is
  beyond device boudnary 126726701056

  I was doing this booted from a live USB image, so I only have pictures
  of the screen, which I will attach.

  I used -d to speed up creation of the ext2 image, but it also happens
  without -d.

To manage notifications about this bug go to:
https://bugs.launchpad.net/btrfs-tools/+bug/1869281/+subscriptions