growpart took too much time to complete and conflict with tmpfiles

[norman shen]

# cloud-init analyze blame | grep growpart
     04.24900s (init-network/config-growpart)

2021-06-17 01:37:52,405 - subp.py[DEBUG]: Running command ['growpart', '--help'] with allowed return codes [0] (shell=False, capture=True)
2021-06-17 01:37:52,427 - util.py[DEBUG]: Reading from /proc/489/mountinfo (quiet=False)
2021-06-17 01:37:52,428 - util.py[DEBUG]: Read 2883 bytes from /proc/489/mountinfo
2021-06-17 01:37:52,429 - util.py[DEBUG]: Reading from /sys/class/block/vda2/partition (quiet=False)
2021-06-17 01:37:52,429 - util.py[DEBUG]: Read 2 bytes from /sys/class/block/vda2/partition
2021-06-17 01:37:52,429 - util.py[DEBUG]: Reading from /sys/devices/pci0000:00/0000:00:05.0/virtio2/block/vda/dev (quiet=False)
2021-06-17 01:37:52,430 - util.py[DEBUG]: Read 6 bytes from /sys/devices/pci0000:00/0000:00:05.0/virtio2/block/vda/dev
2021-06-17 01:37:52,430 - subp.py[DEBUG]: Running command ['growpart', '--dry-run', '/dev/vda', '2'] with allowed return codes [0] (shell=False, capture=True)
2021-06-17 01:37:52,515 - subp.py[DEBUG]: Running command ['growpart', '/dev/vda', '2'] with allowed return codes [0] (shell=False, capture=True)
2021-06-17 01:37:56,633 - util.py[WARNING]: Failed: growpart /dev/vda 2
2021-06-17 01:37:56,634 - util.py[DEBUG]: Failed: growpart /dev/vda 2
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/cloudinit/config/cc_growpart.py", line 156, in resize
    subp.subp(["growpart", diskdev, partnum])
  File "/usr/lib/python3/dist-packages/cloudinit/subp.py", line 295, in subp
    cmd=args)
cloudinit.subp.ProcessExecutionError: Unexpected error while running command.
Command: ['growpart', '/dev/vda', '2']
Exit code: 2
Reason: -
Stdout: FAILED: pt_resize failed
Stderr: /usr/bin/growpart: 554: /usr/bin/growpart: cannot create /tmp/growpart.g8m8DI/pt_update.err: Directory nonexistent
        failed [pt_update:2] pt_update /dev/vda 2
        cat: /tmp/growpart.g8m8DI/pt_update.err: No such file or directory
2021-06-17 01:37:56,652 - util.py[DEBUG]: resize_devices took 4.224 seconds
2021-06-17 01:37:56,652 - cc_growpart.py[DEBUG]: '/' FAILED: failed to resize: disk=/dev/vda, ptnum=2: Unexpected error while running command.
Command: ['growpart', '/dev/vda', '2']
Exit code: 2
Reason: -
Stdout: FAILED: pt_resize failed

In the log, it implies that it took 4s to quit with errors. what is more interesting is that partx finally succeeds to extend partition....