[no subject]

This snippet below limits s_awu_max to 4096(bs) which is the max value
on my platform.

```
static void ext4_atomic_write_init(struct super_block *sb)
{
â??â??â??â??â??â??...
â??â??â??â??â??â??sbi->s_awu_min = max(sb->s_blocksize,
â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??      bdev_atomic_write_unit_min_bytes(bdev));
â??â??â??â??â??â??sbi->s_awu_max = min(sb->s_blocksize,
â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??â??      bdev_atomic_write_unit_max_bytes(bdev));
â??â??â??â??â??â??...
}
```

I am wondering if I missed something? Or if there are any other ways
that I could enable 16kb
atomic write on my platform?

Thanks!
Li Lei