Re: [GIT PULL] Block pull request for- 4.11-rc1

[Jens Axboe]

On 02/25/2017 11:17 AM, hch@xxxxxx wrote:
> On Fri, Feb 24, 2017 at 01:22:42PM -0700, Jens Axboe wrote:
>> Bart, I pushed a fix here:
>>
>> http://git.kernel.dk/cgit/linux-block/commit/?h=for-linus&id=61febef40bfe8ab68259d8545257686e8a0d91d1
> 
> Yeah, this looks fine to me.  It was broken on blk-mq before, but
> basically impossible to hit.  I wonder if we should have a debug mode
> where we set requests to a known pattern after they are freed to catch
> these sort of bugs.

tio/md would probably never change for the same set of requests, so
it worked by happy accident before. Some of the blk-mq state remains
valid after "freeing" a request, but we could selectively fill and
definitely fill the entire PDU area with free poison.

-- 
Jens Axboe