On Thu, Feb 13, 2025 at 09:29:53AM +0800, Ming Lei wrote: > Yeah, turns out oops is triggered in initializing req_iterator for > discard req, and the following patch should be enough: How do we end up in blk_rq_map_sg for a discard request here? dma-mapping doesn't make sense for a non-special pyaload discard as used by xxen-blkfront, and xen-blkfront also only calls blk_rq_map_sg from blkif_queue_rw_req and not blkif_queue_discard_req.
