On 06/04/2014 12:28 PM, Keith Busch wrote: > On Wed, 4 Jun 2014, Matias Bjørling wrote: >> On 06/04/2014 12:27 AM, Keith Busch wrote: >>>> On Tue, 3 Jun 2014, Matias Bjorling wrote: >>>>> >>>>> Keith, will you take the nvmemq_wip_v6 branch for a spin? Thanks! >>> >>> BTW, if you want to test this out yourself, it's pretty simple to >>> recreate. I just run a simple user admin program sending nvme >>> passthrough >>> commands in a tight loop, then run: >>> >>> # echo 1 > /sys/bus/pci/devices/<bdf>/remove >> >> I can't recreate- I use the nvme_get_feature program to continuously >> hit the ioctl path, testing using your nvme qemu branch. > > Okay, I'll try to fix it. > > I think there are multiple problems, but the first is that since there > is no gendisk associated with the admin_q, the QUEUE_FLAG_INIT_DONE flag > is never set, and blk_mq_queue_enter returns successful whenever this > flag is not set even though this queue is dying, so we enter with all > its invalid pointers. > > Here's a couple diff's. The first fixes the kernel oops by not entering a > dying queue. The second is just a few unrelated clean-ups in nvme-core.c. > > I still can't complete my current hot-removal test, though; something > appears hung, but haven't nailed that down yet. > > Please let me know what you think! Thanks. > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index d10013b..5a9ae8a 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -105,6 +105,10 @@ static int blk_mq_queue_enter(struct request_queue *q) > __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); > smp_wmb(); > /* we have problems to freeze the queue if it's initializing */ > + if (blk_queue_dying(q)) { > + __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); > + ret = -ENODEV; > + } > if (!blk_queue_bypass(q) || !blk_queue_init_done(q)) > return 0;
Are you testing against 3.13? You really need the current tree for this, otherwise I'm sure you'll run into issues (as you appear to be :-) -- 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/