CEPH_FSCRYPT_BLOCK_MASK
((offset | len) & ~CEPH_FSCRYPT_BLOCK_MASK)) {
num_blocks = ceph_fscrypt_blocks(off, len & CEPH_FSCRYPT_BLOCK_MASK);
if ((ext->off | ext->len) & ~CEPH_FSCRYPT_BLOCK_MASK) {
num_blocks = ceph_fscrypt_blocks(off, len & CEPH_FSCRYPT_BLOCK_MASK);
*off &= CEPH_FSCRYPT_BLOCK_MASK;