> On Wed, Sep 17, 2014 at 10:22 PM, Jens Axboe <axboe@xxxxxxxxx> wrote: > > > > Another way would be to ensure that the timeout handler doesn't touch hw_ctx > > or tag_sets that aren't fully initialized yet. But I think this is > > safer/cleaner. > > That may not be easy or enough to check if hw_ctx/tag_sets are > fully initialized if you mean all requests have been used one time. > > On Wed, Sep 17, 2014 at 10:11 PM, David Hildenbrand > > I was playing with a simple patch that just sets cmd_flags and action_flags to > > What is action_flags? atomic_flags, sorry :) Otherwise e.g. REQ_ATOM_STARTED could already be set due to the randomness. I am not sure if this is really necessary, or if it is completely shielded by the tag-handling code, but seemed to be clean for me to do it (and I remember it not being set within blk_mq_rq_ctx_init). > > > 0. That should already be sufficient to hinder blk_mq_tag_to_rq and the calling > > method to do the wrong thing. > > Yes, clearing rq->cmd_flags should be enough. > > And looks better to move rq initialization to __blk_mq_free_request() > too, otherwise timeout still may see old cmd_flags and rq->q before > rq's new initialization. Yes, __blk_mq_free_request() should also reset at least rq->cmd_flags, and I think we can remove the initialization from __blk_mq_alloc_request(). David > > > Thanks, -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
