On Thu, Sep 16, 2021 at 08:38:16PM +0800, Ming Lei wrote: > > > and it may cause other trouble at least for scsi disk since sd_shutdown() > > > follows del_gendisk() and has to be called before blk_cleanup_queue(). > > > > Yes. So we need to move the bits of blk_cleanup_queue that deal with > > the file system I/O state to del_gendisk, and keep blk_cleanup_queue > > for anything actually needed for the low-level queue. > > Can you explain what the bits are in blk_cleanup_queue() for dealing with FS > I/O state? blk_cleanup_queue() drains and shutdown the queue basically, > all shouldn't be related with gendisk, and it is fine to implement one > queue without gendisk involved, such as nvme admin, connect queue or > sort of stuff. > > Wrt. this reported issue, rq_qos_exit() needs to run before releasing > gendisk, but queue has to put into freezing before calling > rq_qos_exit(), I was curious what you hit, but yes rq_qos_exit is obvious. blk_flush_integrity also is very much about fs I/O state. > so looks you suggest to move the following code into > del_gendisk()? something like that. I think we need to split the dying flag into one for the gendisk and one for the queue first, and make sure the queue freeze in del_gendisk is released again so that passthrough still works after. > If we move the above into del_gendisk(), some corner cases have to be > taken care of, such as request queue without disk involved. Yes.
