On Wed, May 14, 2025 at 01:29:37PM -0700, Bart Van Assche wrote: > +/* > + * Do not call bio_queue_enter() if the BIO_ZONE_WRITE_PLUGGING flag has been > + * set because this causes blk_mq_freeze_queue() to deadlock if > + * blk_zone_wplug_bio_work() submits a bio. Calling bio_queue_enter() for bios > + * on the plug list is not necessary since a q_usage_counter reference is held > + * while a bio is on the plug list. > + */ How do we end up with BIO_ZONE_WRITE_PLUGGING set here? If that flag was set in a stacking driver we need to clear it before resubmitting the bio I think. Can you provide a null_blk based reproducer for your testcase to see what happens here? Either way we can't just simply skip taking q_usage_count.
