[Git-commits] [grml/grml2usb] 272b66: Fix race condition with blockdev/BLKRRPART due to ...

[Michael Prokop]

  Branch: refs/heads/master
  Home:   https://github.com/grml/grml2usb
  Commit: 272b66ed0ec6a5faa3d36d75843b34d8d6c01d12
      https://github.com/grml/grml2usb/commit/272b66ed0ec6a5faa3d36d75843b34d8d6c01d12
  Author: Michael Prokop <mika at grml.org>
  Date:   2020-11-17 (Tue, 17 Nov 2020)

  Changed paths:
    M grml2usb

  Log Message:
  -----------
  Fix race condition with blockdev/BLKRRPART due to lack of fsync

Quoting dann frazier from Debian's #975015:

| grml2usb autopkgtest frequently fail in Ubuntu's CI.
| [...]
| 2020-11-17 14:14:49,433 Probing device via 'blockdev --rereadpt /dev/loop0'
| blockdev: ioctl error on BLKRRPART: Device or resource busy
| 2020-11-17 14:14:49,452 Execution failed: ("Couldn't execute blockdev on '%s' (install util-linux?)", '/dev/loop0')
|
| I am able to reproduce this on an OpenStack instance with a failure rate of
| 33% (36 failures, 110 passes). My theory is that the sync is not sufficient,
| and that we really need to do a targeted fsync of the file. With the
| attached patch, I've yet to see a failure in 42 iterations.

Thanks: dann frazier <dannf at dannf.org> for bug report and patch
Closes: #975015