ecryptfs_read_lower
rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size,
rc = ecryptfs_read_lower(page_virt, lower_offset, PAGE_SIZE,
rc = ecryptfs_read_lower(file_size, 0, ECRYPTFS_SIZE_AND_MARKER_BYTES,
int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
rc = ecryptfs_read_lower(virt, offset, size, ecryptfs_inode);