Re: [PATCH] block: Avoid divide by 0 when max_discard_sectors is 0

From: Doug Anderson
Date: Tue Dec 18 2012 - 20:31:33 EST


On Tue, Dec 18, 2012 at 4:42 PM, David Rientjes <rientjes@xxxxxxxxxx> wrote:
> On Tue, 18 Dec 2012, Doug Anderson wrote:
>> The recent commit "block: discard granularity might not be power of 2"
>> introduced a divide by 0 in the kernel. Previously the code didn't
>> try to divide by discard_granularity when max_discard_sectors was 0.
>> Fix the code to only do the division if max_discard_sectors is
>> specified.
> Could you try Linus' patch at
> and give your Tested-by
> if it solves your issue?

Hoo boy. Thanks for the pointer. I missed that when searching to see
if this had already been fixed. :(

I'm pretty sure Linus's patch will fix my problem since I think my
system has "max_discard_sectors" as 0 and his patch has the same
effect as mine: avoid the divide by 0. Someone else will need to test
his patch on a system that actually uses discard. In any case, I will
test and send a Tested-by as soon as I'm able.

Please consider my patch abandoned.

> Thanks.
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