Comment # 17 on bug 1222429 from Stefan Hundhammer

(In reply to David Sterba from comment #16)
> Please note that the 'ro' mount option semantics does not prevent writes to
> happen before the mount is finished, the writes are prevented from user
> space. IOW, log replay can still happen with 'ro' mount so you need some
> sort of log replay preventing option, or to temporarily make the block
> device read-only (blockdev --setro).

That's a good hint. I assume this affects only the currently running kernel and
processes, and nothing is written to the device, correct?