LOOP_MAJOR
MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR);
disk->major = LOOP_MAJOR;
if (__register_blkdev(LOOP_MAJOR, "loop", loop_probe)) {
unregister_blkdev(LOOP_MAJOR, "loop");
return i && S_ISBLK(i->i_mode) && imajor(i) == LOOP_MAJOR;