Messages in this thread Patch in this message | | | Subject | Re: bio linked list corruption. | From | Jens Axboe <> | Date | Wed, 26 Oct 2016 17:03:45 -0600 |
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On 10/26/2016 04:58 PM, Linus Torvalds wrote: > On Wed, Oct 26, 2016 at 3:51 PM, Linus Torvalds > <torvalds@linux-foundation.org> wrote: >> >> Dave: it might be a good idea to split that "WARN_ON_ONCE()" in >> blk_mq_merge_queue_io() into two > > I did that myself too, since Dave sees this during boot. > > But I'm not getting the warning ;( > > Dave gets it with ext4, and thats' what I have too, so I'm not sure > what the required trigger would be.
Actually, I think I see what might trigger it. You are on nvme, iirc, and that has a deep queue. Dave, are you testing on a sata drive or something similar with a shallower queue depth? If we end up sleeping for a request, I think we could trigger data->ctx being different.
Dave, can you hit the warnings with this? Totally untested...
diff --git a/block/blk-mq.c b/block/blk-mq.c index ddc2eed64771..80a9c45a9235 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1217,9 +1217,7 @@ static struct request *blk_mq_map_request(struct request_queue *q, blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx); rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
- hctx->queued++; - data->hctx = hctx; - data->ctx = ctx; + data->hctx->queued++; return rq; }
-- Jens Axboe
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