Re: [2.6.23 PATCH 07/18] dm io: fix panic on large request

[Patrick McHardy <kaber@trash.net>]

Jun'ichi Nomura wrote:
>>>From: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
>>>
>>>bio_alloc_bioset() will return NULL if 'num_vecs' is too large.
>>>Use bio_get_nr_vecs() to get estimation of maximum number.
>>>
>>>Signed-off-by: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
>>>Signed-off-by: Alasdair G Kergon <agk@redhat.com>
>>>
>>
>>This patch reproducibly oopses my box:
> 
> 
> Thanks for the report.
> But I'm not sure how the patch is related to the oops.
> 
> The stack trace shows the oops occurred in dm-crypt,
> which doesn't use the part of the code modified by the patch
> (dm-io).


I tried reverting the individual patches until it stopped oopsing,
it may have been by luck. I'll try if I can break it again by
reverting the revert.

> Are you using other dm modules such as dm-multipath, dm-mirror
> or dm-snapshot?
> If so, can you take the output of 'dmsetup table' and 'dmsetup ls'?


No other modules.

> Do you have a reliable way to reproduce the oops which I can try?


"/etc/init.d/cryptdisk start" (debian) on a luks partition triggered
it for me.