On Wed, Dec 24 2014 at 1:21pm -0500, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > This is odd considering blk-mq defaults to setting QUEUE_FLAG_IO_STAT, > so each request will have REQ_IO_STAT set. > > I'm not sure what would account for this NULL pointer (my code appears > to be slightly different than yours but AFAICT req->part is NULL in your > crash, which shouldn't ever happen if IO stats are enabled). > > Are you manually enabling/disabling IO stats via sysfs at all? Answering my own question: unlikely. Considering I was able to reproduce merely by creating an mpath device ontop of a blk-mq device (now that dm-mpath.c:__multipath_map sets rq->rq_disk). I'll try to get to the bottom of it (it still seems pretty weird to me). -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
