[Bug 2100848] Re: "short read" error when resizing LVM in Azure virtual machine

[Alexander Corrie]

This is the working strace on 1.1 for comparison.

** Attachment added: "strace-resize2fs-1-1.log"
   https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/2100848/+attachment/5862078/+files/strace-resize2fs-1-1.log

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Title:
  "short read" error when resizing LVM in Azure virtual machine

Status in e2fsprogs package in Ubuntu:
  New

Bug description:
  Description:    Ubuntu 20.04.6 LTS
  Release:        20.04

  e2fsprogs:
    Installed: 1.45.5-2ubuntu1.2
    Candidate: 1.45.5-2ubuntu1.2

  On Azure VMs (but not AWS) when I try and run resize2fs on an LVM disk
  I get the following:

  ```
  me:~$ sudo resize2fs /dev/mapper/data-data
  resize2fs 1.45.5 (07-Jan-2020)
  resize2fs: Attempt to read block from filesystem resulted in short read while trying to open /dev/mapper/data-data
  Couldn't find valid filesystem superblock.
  ```

  When I downgrade to 1.1 ( `sudo apt install -y --allow-downgrades
  libext2fs2=1.45.5-2ubuntu1.1 e2fsprogs=1.45.5-2ubuntu1.1` ) it works
  as expected.

  ```
  me:~$ sudo resize2fs /dev/mapper/data-data
  resize2fs 1.45.5 (07-Jan-2020)
  The filesystem is already 16776192 (4k) blocks long.  Nothing to do!
  ```

  This is reproducible across multiple azure kernel versions (this VM is
  on 5.15.0-1079-azure but it's been happening since 1.45.5-2ubuntu1.2).

  Some more output for the filesystem setup. I've also attached an
  strace on 1.2.

  ```
  me:~$ lsblk
  NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
  loop0         7:0    0 63.7M  1 loop /snap/core20/2434
  loop1         7:1    0 44.4M  1 loop /snap/snapd/23545
  loop2         7:2    0 91.9M  1 loop /snap/lxd/29619
  loop3         7:3    0  4.8G  0 loop /var/tmp
  sda           8:0    0   64G  0 disk
  ├─sda1        8:1    0 63.9G  0 part /
  ├─sda14       8:14   0    4M  0 part
  └─sda15       8:15   0  106M  0 part /boot/efi
  sdb           8:16   0   75G  0 disk
  └─sdb1        8:17   0   75G  0 part /mnt
  sdc           8:32   0   64G  0 disk
  └─data-data 253:0    0   64G  0 lvm  /var
  sr0          11:0    1 1024M  0 rom
  ```

  ```
  me:~$ df -h
  Filesystem             Size  Used Avail Use% Mounted on
  /dev/root               62G   21G   41G  34% /
  devtmpfs               7.9G     0  7.9G   0% /dev
  none                   3.2G  544K  3.2G   1% /dev/shm
  tmpfs                  1.6G   21M  1.6G   2% /run
  tmpfs                  1.6G     0  1.6G   0% /run/lock
  tmpfs                  7.9G     0  7.9G   0% /sys/fs/cgroup
  /dev/mapper/data-data   63G  5.7G   54G  10% /var
  /dev/sda15             105M  6.1M   99M   6% /boot/efi
  /dev/loop0              64M   64M     0 100% /snap/core20/2434
  /dev/loop2              92M   92M     0 100% /snap/lxd/29619
  /dev/loop1              45M   45M     0 100% /snap/snapd/23545
  /dev/sdb1               74G   28K   70G   1% /mnt
  tmpfs                  1.6G     0  1.6G   0% /run/user/1000
  tmpfs                  4.7G  148K  4.7G   1% /tmp
  none                   800M     0  800M   0% /var/crash
  /dev/loop3             4.7G  160K  4.4G   1% /var/tmp
  ```

  I would expect the command to work on 1.2 as it does on 1.1 and resize
  the LVM without erroring and not resizing it.

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