ext4_getfsmap_dev
const struct ext4_getfsmap_dev *d1 = p1;
const struct ext4_getfsmap_dev *d2 = p2;
struct ext4_getfsmap_dev handlers[EXT4_GETFSMAP_DEVS];
sort(handlers, EXT4_GETFSMAP_DEVS, sizeof(struct ext4_getfsmap_dev),