On Fri, Jun 04, 2021 at 10:04:46PM +0300, Alper Nebi Yasak wrote:
Some filesystem tests are failing when their image is prepared with guestmount, but succeeding if loop mounts are used instead. The reason seems to be a race condition the guestmount(1) manual page explains:
When guestunmount(1)/fusermount(1) exits, guestmount may still be running and cleaning up the mountpoint. The disk image will not be fully finalized. This means that scripts like the following have a nasty race condition: guestmount -a disk.img -i /mnt # copy things into /mnt guestunmount /mnt # immediately try to use 'disk.img' ** UNSAFE ** The solution is to use the --pid-file option to write the guestmount PID to a file, then after guestunmount spin waiting for this PID to exit.The Python standard library has an os.waitpid() function for waiting a child to terminate, but it cannot wait on non-child processes. Implement a utility function that can do this by polling the process repeatedly for a given duration, optionally killing the process if it won't terminate on its own. Apply the suggested solution with this utility function, which makes the failing tests succeed again.
Signed-off-by: Alper Nebi Yasak alpernebiyasak@gmail.com Reviewed-by: Simon Glass sjg@chromium.org
Applied to u-boot/master, thanks!