EXT4_XATTR_ROUND
EXT4_XATTR_ROUND - sizeof(__u32));
if (free > EXT4_XATTR_ROUND)
free = EXT4_XATTR_SIZE(free - EXT4_XATTR_ROUND);
(((name_len) + EXT4_XATTR_ROUND + \
sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)