Re: Problem with DISCARD and RAID10

[Shaohua Li <shli@kernel.org>]

On Tue, Nov 06, 2012 at 05:32:26PM +0800, Brad Campbell wrote:
> G'day Shaohua,
> 
> I'm testing Vanilla 3.7.0-rc4 and bumping up against squillions of these :
> 
> [   41.094726] request botched: dev sdc: type=1, flags=122d8081
> [   41.094774]   sector 28317178, nr/cnr 0/32
> [   41.094815]   bio ffff8807fe885300, biotail ffff8807fe887300,
> buffer           (null), len 0
> [   41.100045] request botched: dev sda: type=1, flags=122d8081
> [   41.100094]   sector 28317403, nr/cnr 0/32
> [   41.100134]   bio ffff8807fe885840, biotail ffff8807fe887840,
> buffer           (null), len 0
> [   41.100718] request botched: dev sdb: type=1, flags=122d8081
> [   41.100767]   sector 28317179, nr/cnr 0/224
> [   41.100808]   bio ffff8807fe885a80, biotail ffff8807fe887d80,
> buffer           (null), len 0
> [   41.104649] request botched: dev sdc: type=1, flags=122d8081
> [   41.104697]   sector 28317179, nr/cnr 0/224
> [   41.104738]   bio ffff8807fe886000, biotail ffff8807fe887300,
> buffer           (null), len 0

cc Martin to check if he has idea.

Hmm, I thought such problem is already fixed by Martin's discard merge patches
and my last test in SATA SSD doesn't show this problem. Maybe there is still
a corner case we didn't handle discard request merge well. Time run out today,
I'll check tomorrow.

Thanks,
Shaohua