From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0)

Description of problem:
Trying to run "raidstop /dev/md0" will always report that the raid is 
still in use.

How reproducible:
Always

Steps to Reproduce:
1. create and start a raid on /dev/md0
2. run "raidstop /dev/md0"
3. poof, error.
	

Actual Results:  raidstop claims that md0 is still in use.

Expected Results:  Raid should stop.

Additional info:

It looks like the raidtools are doing a version check on the md driver 
(version.c), but for some reason, the "close" has been commented out, and 
this leaves /dev/md0 open, which increases the usage counter in the md 
driver, so that the "stop" IOCTL will fail.

I worked around this by hex-editing raidstop (I didn't have the source at 
the time) to use /dev/md1 for version checking (it's hardcoded in the 
source).  This left the counters for md0 untouched, and I was able to stop 
the raid.

This is a serious problem for anyone working with raids where the raid 
does not live from boot to boot.