Include DVD reading fixes

Hello!

Phillipp has asked me whether I could send commits:

cba22d86e0a1 bdev: Refresh bdev size for disks without partitioning 731dc4868311 bdev: Factor out bdev revalidation into a common helper

for inclusion into stable. I've noticed they are already in 5.4-stable but they didn't seem to propagate into say 4.19-stable although they apply just fine there. Any reason for that?

The fixes fix mounting of encrypted UDF media for some setups and they are reasonably safe so I'm fine with pushing them to stable.

Thanks! Honza