Created attachment 438437 [details]
the patched code

Description of problem:
i've been told that it wasn't testing the i/o accurately because it was choosing its starting location as a random number of bytes into the disk, then the most of the time you will need to read two sectors to get 512 bytes.
only if you choose a starting byte divisible by 512 will you read your whole 512 bytes from a single sector. Using direct i/o with memory and buffer alignment fixes this issue as well. One of my colleagues (Mr. Ian Sherratt) patched this, so i don't have a good understanding of the code. I've attached the patched version

Version-Release number of selected component (if applicable):


How reproducible:
always

Steps to Reproduce:
1. just running the test
2.
3.
  
Actual results:
n/a

Expected results:
n/a

Additional info: