XFS_MIN_BLOCKSIZE
xfs_daddr_t readPos = blockToRead * XFS_MIN_BLOCKSIZE + offset * len;
uint64 readPos = actualBlockToRead * (XFS_MIN_BLOCKSIZE);
+ howManyBlocksFurther) / XFS_MIN_BLOCKSIZE;
|| sb_blocksize < XFS_MIN_BLOCKSIZE
if (XFS_MIN_BLOCKSIZE > sb_blocksize) {