kern/44251: RAID1 configuration fails if component 0 has been replaced

[pooka%iki.fi@localhost]

>Number:         44251
>Category:       kern
>Synopsis:       RAID1 configuration fails if component 0 has been replaced
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Dec 18 09:40:00 +0000 2010
>Originator:     Antti Kantee
>Release:        
>Organization:
>Environment:
>Description:
In case component 1 is replaced from a RAID1, the raid can still be
configured with the component marked as "failed".  However, if
component 0 fails the raid configuration fails completely.

Greg Oster says this is because the label voting code in
rf_CheckLabels() happens to depend on the order of components
and in case the votes are tied the first component examined is
assumed to be correct.
>How-To-Repeat:
run tests/dev/raidframe/t_raid raid1_comp0fail (to be added very soon)
>Fix: