[Bug 2036467] Re: superblock checksum mismatch in resize2fs

[Robby Pocase]

@Krister additionally, can you clarify "occasionally"? It's clearly
frequently enough to prioritize upstreaming a fix. Knowing frequency
could aide in priority internally.

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https://bugs.launchpad.net/bugs/2036467

Title:
  superblock checksum mismatch in resize2fs

Status in cloud-images:
  New
Status in e2fsprogs package in Ubuntu:
  Confirmed
Status in e2fsprogs source package in Focal:
  New
Status in e2fsprogs source package in Jammy:
  New
Status in e2fsprogs source package in Mantic:
  Confirmed

Bug description:
  Hi,
  We run ext4 on EBS volumes on EC2.  During provisioning, cloud-init will occasionally report that resize2fs has failed due to a superblock checksum mismatch.  We debugged this internally, and were able to come up with the following reproducer:

     #!/usr/bin/bash
     set -euxo pipefail

     while true
     do
             parted /dev/nvme1n1 mklabel gpt mkpart primary 2048s 2099200s
             sleep .5
             mkfs.ext4 /dev/nvme1n1p1
             mount -t ext4 /dev/nvme1n1p1 /mnt
             stress-ng --temp-path /mnt -D 4 &
             STRESS_PID=$!
             sleep 1
             growpart /dev/nvme1n1 1
             resize2fs /dev/nvme1n1p1
             kill $STRESS_PID
             wait $STRESS_PID
             umount /mnt
             wipefs -a /dev/nvme1n1p1
             wipefs -a /dev/nvme1n1
     done

  (This was on a 60gb gp3 volume attached to a c5.4xlarge)

  We were able to find a fix that works and get the patch accepted
  upstream.  The short explanation is that by switching the superblock
  read to direct io, we no longer see the problem.

  The patch is available here, but hasn't been published in a released
  version of e2fsprogs:

  https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/commit/?id=43a498e938887956f393b5e45ea6ac79cc5f4b84

  A longer thread with the maintainer is available here:

  https://lore.kernel.org/linux-ext4/20230609042239.GA1436857@mit.edu/

  This bug report is to request that Ubuntu backport this patch to the
  versions of e2fsprogs that are in releases that are available in
  images on AWS, preferably Focal and Jammy.

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