Hello, Ming Lei. I'd like to hear your comment on this patch regarding the ordering of stopping kernel thread. > In order to enforce this strategy, this patch inversed > loop_reread_partitions() and loop_unprepare_queue() in loop_clr_fd(). > I don't know whether it breaks something, but I don't have testcases. Until 3.19, kthread_stop(lo->lo_thread) was called before ioctl_by_bdev(bdev, BLKRRPART, 0) is called. During 4.0 to 4.3, the loop module was using "kloopd" workqueue. But since 4.4, loop_reread_partitions(lo, bdev) is called before loop_unprepare_queue(lo) is called. And this patch is trying to change to call loop_unprepare_queue() before loop_reread_partitions() is called. Is there some reason we need to preserve current ordering? Relevant commits: commit b5dd2f6047ca108001328aac0e8588edd15f1778 block: loop: improve performance via blk-mq commit e03a3d7a94e2485b6e2fa3fb630b9b3a30b65718 block: loop: use kthread_work
