Messages in this thread | | | Subject | Re: Fwd: 4.4-rc2 crash: block related | From | Jens Axboe <> | Date | Wed, 25 Nov 2015 09:30:39 -0700 |
| |
On 11/25/2015 01:39 AM, Jan Kara wrote: > On Wed 25-11-15 08:27:56, Mika Penttilä wrote: >> With recent block layer pull i see a 100% repeatable crash on boot while >> mounting roots (ext4 partition on eMMC, with cfq io scheduler). > > Thanks for report! After some investigation I found out we allocate > elevator specific data in __get_request() only for non-flush requests. And > this is actually required since the flush machinery uses the space in > struct request for something else. Doh. So my patch is just wrong and not > easy to fix since at the time __get_request() is called we are not sure > whether the flush machinery will be used in the end. Jens, please revert > 1b2ff19e6a957b1ef0f365ad331b608af80e932e. Thanks! > > I'm somewhat surprised that you can reliably hit the race where flushing > gets disabled for the device just while the request is in flight. But I > guess during boot it makes some sense.
Yeah, that's impressive. I'll revert it and get it sent up before -rc3 is cut.
-- Jens Axboe
| |