Re: block: re-add discard_granularity and alignment checks

[Ming Lin]

On Thu, Oct 22, 2015 at 10:03 AM, Mike Snitzer <snitzer@xxxxxxxxxx> wrote:
> On Thu, Oct 22 2015 at 12:59pm -0400,
> Ming Lin <mlin@xxxxxxxxxx> wrote:
>
>> From: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
>>
>> In commit b49a087("block: remove split code in
>> blkdev_issue_{discard,write_same}"), discard_granularity and alignment
>> checks were removed. Ideally, with bio late splitting, the upper layers
>> shouldn't need to depend on device's limits.
>>
>> Christoph reported a discard regression on the HGST Ultrastar SN100 NVMe
>> device when mkfs.xfs. We have not found the root cause yet.
>>
>> This patch re-adds discard_granularity and alignment checks by reverting
>> the related changes in commit b49a087. The good thing is now we can
>> remove the 2G discard size cap and just use UINT_MAX to avoid bi_size
>> overflow.
>>
>> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
>> Tested-by: Christoph Hellwig <hch@xxxxxx>
>> Signed-off-by: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
>
> Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>

Hi Jens,

Would you please take this one?

>
> Thanks!
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/