multipathd expecting wrong paths in uevents

Binary package hint: multipath-tools

multipathd is looking for the wrong paths in uevents, causing it to miss when paths go down. This has been fixed upstream for awhile, and is fixed in Natty. The fix needs to be backported to Lucid and Maverick.

SRU Justification:
1. Impact: multipath fail-over events are not handled by multipathd. The system therefore does not cleanly survive FOFB.
2. How addressed: a bug from upstream is cherry-picked which fixes multipathd to look for the correct device pathnames in uevents it sees.
3. Patch: see debdiff attached
4. To reproduce: Start multipathd with -v4 argument. Reset an SCM to initiate FOFB. Watch /var/log/daemon.log for uevents relating to drives. Without the patch they don't show up. Additionally, upon failback, new block device names will be used (i.e. /dev/sdo instead of /dev/sda).
5. Regression potential: the patch is to multipathd, so non-multipath users will not be affected. Multipathd users with an older kernel which uses the old pathanames could get the same behavior which uptodate users now have without this patch.