On 12/05/2013 04:16 PM, Dave Chinner wrote: > On Fri, Dec 06, 2013 at 08:26:51AM +1100, Dave Chinner wrote: >> On Thu, Dec 05, 2013 at 10:22:20PM +0800, Ming Lei wrote: >>> On Wed, 4 Dec 2013 12:58:38 +1100 >>> Dave Chinner <da...@fromorbit.com> wrote: >>> >>>> >>>> And I just hit this from running xfs_repair which is doing >>>> multithreaded direct IO directly on /dev/vdc: >> ..... >>>> So this is looking like another virtio+blk_mq problem.... >>> >>> This one might be caused by using-after-'free' request because the freed >>> request may be allocated to another CPU immediately, and the below patch >>> may be helpful, would you mind testing it? >>> >>> diff --git a/block/blk-mq.c b/block/blk-mq.c >>> index 6875736..2358bdf 100644 >>> --- a/block/blk-mq.c >>> +++ b/block/blk-mq.c >>> @@ -311,12 +311,12 @@ void blk_mq_complete_request(struct request *rq, int >>> error) >>> >>> blk_account_io_completion(rq, bytes); >>> >>> + blk_account_io_done(rq); >>> + >>> if (rq->end_io) >>> rq->end_io(rq, error); >>> else >>> blk_mq_free_request(rq); >>> - >>> - blk_account_io_done(rq); >>> } >>> >>> void __blk_mq_end_io(struct request *rq, int error) >> >> Testing it now. I'll let you know how it goes in couple of hours. > > Ok, this looks like it is working correctly. The read/write io stats > are now working properly, too. Thanks for finding the problem > quickly!
Great, thanks for testing, Dave. The fix is now in Linus' tree. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
