Comment 16 for bug 1843328

Well, I did the tests in a fresh installation.

At first everything was ok. So I verified that only UDisks version 2 was installed.
This version does not use DBUS, only version 1. So I found the problem.

Then you can easily reproduce the problem.
With UDisks version 1, you execute the commands:

$ udisks --mount /dev/sdb1
Mounted /org/freedesktop/UDisks/devices/sdb1 at /media/Kindle

$ grep Kindle /proc/mounts
/dev/sdb1 /media/Kindle vfat rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0022,dmask=0077,codepage=437,iocharset=ascii,shortname=mixed,showexec,utf8,errors=remount-ro 0 0

$ udisks --unmount /dev/sdb1

Now, using UDisks version 2:

$ udisksctl mount -b /dev/sdb1
Mounted /dev/sdb1 at /run/media/user/Kindle

$ grep Kindle /proc/mounts
/dev/sdb1 /run/media/user/Kindle vfat rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,showexec,utf8,flush,errors=remount-ro 0 0

$ udisksctl unmount -b /dev/sdb1
Unmounted /dev/sdb1.

As you can see only in version 2, UDisks adds "flush" to the mount options.

My Versions:
OS: Fedora 33
UDisks 1: udisks-1.0.5
UDisks 2: udisks2-2.9.1

Yes. I tested it on a notebook and desktop.