> I was planning on just letting i/o errors return EFAULT to the application.
> I can't think of an application that would really care whether a read()
> failed because of bogus arguments vs. an i/o error.  either way, the data
> doesn't get where it was supposed to go.

The program?   No.   Somebody debugging the program?   Yes.

> does anyone feel it's important to retain EIO returns for real i/o errors
> in the filesystem?  there's a performance benefit for letting them turn
> into EFAULT (or so the theory goes).

I think it's important.   Whether or not its crucial is a judgement
call, but I definitely think it's important.

			       _MelloN_