The sg info result never returns a nonzero result despite SG_FLAG_DIRECT_IO flag and aligned READ_10 and WRITE_10 data buffer. Is direct io occuring as requested? If not, why not? If so, why doesn't the info value behave as documented in the HOWTO? I've run both over usb (which I can understand why not direct) and to SATA drives that normally work fine with O_DIRECT read/write.
This bug is against obsolete kernel. Try newer kernel to see if bug is fixed. Thanks Nick