[PATCH 0/2][RFC] add detailed error values to block layer

[Mike Christie <michaelc@cs.wisc.edu>]

I saw that the Adaptec RAID developers are in need of detailed IO
error values too, so I wanted to post what I have so we can try to
work together. I have converted the block layer, but have not finished
the end request callers.

01-ec-core.patch just defines the error values, and modifies the request
completion functions. Right now they just convert the uptodate status to
an error value. Per Jeff's advice I did not define my own erronos.
wrt his other comment, I was not sure if wanted me to print the error
value in string form in __end_that_request, or just print the numerical
value.

02-ec-bioendio.patch converts the bio_endio and bi_end_io
callers to pass one of the error values defined above instead of
the -Exxx.

Both patches were built against 2.6.5-rc1.

The block layer error values are not too exciting. There were very few
drivers that did not just return EIO. The end request users
will be much more fun :)

Thanks,

Mike Chrisite