On Thu, 05 Apr 2012 14:23:16 -0400 Phillip Susi [off-list ref] wrote:

On 4/4/2012 9:13 PM, NeilBrown wrote:

quoted

That bug is fixed by

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=c744a65c1e2d59acc54333ce80a5b0702a98010b

and is not specific to Intel IMSM RAID.

That commit appears to have to do with shutdown, but this did not happen 
during shutdown.  I suppose it happened as a result of the array being 
stuck in read only mode due to the missing mdmon.

Yes, you are right - I read too hastily.

Something wrote to the md device despite it being marked 'read-only'.
Some filesystems do that to replay their journal.  totally inexcusable
behaviour, but what can we do....

I'm surprised that would happen during installation though.
But certainly the array is marked read-only, and certainly something is
writing to it, and that is the real bug.

NeilBrown