James Bottomley wrote: > commit e8939a50466fd963eb1ba9118c34b9ffb7ff6aa6 > Author: Tejun Heo <tj@xxxxxxxxxx> > Date: Fri May 8 11:54:16 2009 +0900 > > block: implement and enforce request peek/start/fetch > > Added a BUG_ON(blk_queued_rq(req)) to the top of blk_finish_req(). > Unfortunately, this checks whether req->queuelist is empty. This list > is doing double duty both as the queue list and the tag list, so tagged > requests come in here with this not empty and boom (the tag list is > emptied by blk_queue_end_tag() lower down). > > Fix this by moving the BUG_ON to below the end tag we also seem > vulnerable to this in blk_requeue_request() as well. I think all uses > of blk_queued_rq() need auditing because the check is clearly wrong in > the tagged case. > > Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Oops, Acked-by: Tejun Heo <tj@xxxxxxxxxx> There are also some drivers which use queuelist for internal purposes after dequeueing, which also screws up blk_queued_rq() test in addition to being questionable practice to begin with. Maybe we would be better off with a flag? Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
