Re: [OOPS] 2.6.21-rc6-git5 in cfq_dispatch_insert

From: Brad Campbell
Date: Wed Apr 25 2007 - 04:50:55 EST

Neil Brown wrote:

How likely it would be to get two requests with the same sector number
I don't know. I wouldn't expect it to ever happen - I have seen it
before, but it was due to a bug in ext3. Maybe XFS does it
intentionally some times?

It certainly sounds like an odd thing to occur.

Even stranger that it's easier to hit on a degraded array or an array being checked.

I *am* using ext3 on this box (and all my boxes in fact)

You could test this theory by putting a
WARN_ON(cfqq->next_rq == NULL);
at the end of cfq_reposition_rq_rb, just after the cfq_add_rq_rb call.

I've done that.. now to wait for it to hit again.

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