Bug#417407: Improve safety of os-prober by ignoring active swap and using "blockdev --setro" when available

["Alex Owen" <r.alex.owen@gmail.com>]

clone 417407 -1
reassign -1 util-linux
retitle -1 util-linux: wish there was a blockdev-udeb
severity -1 wishlist
reassign 417407 os-prober
tags  417407 +patch
retitle 417407 os-prober: protect partitions with "blockdev --setro"
when available
thanks

Attached is a patch to os-prober to:
(1) make it ignore active swap
[Changes in: os-prober/os-prober]

(2) if blockdev is available then use it to set partitions read-only
before mounting to work arround a "feature" of ext3 and possible other
journaled filesystems!
[Changes in: os-prober/os-probes/common/50mounted-tests]

I do not claim to have tested the patch. I have tried to write the
patch so that (2) does nothing if blockdev is not there... Perhaps
this means the deb should recommend util-linux while the udeb could
require blockdev-udeb?

I have cloned this bug as a wishlist against util-linux requesting a
blockdev-udeb.

Regards
Alex Owen