Hi, Christoph,
Christoph Hellwig <[email protected]> writes:
> On Mon, Mar 14, 2016 at 05:10:00PM -0400, Jeff Moyer wrote:
>> dio_bio_complete turns all errors into -EIO. This is historical,
>> since you used to only get 1 bit precision for errors (BIO_UPTODATE).
>> Now that we get actual error codes, we can return the appropriate
>> code to userspace. File systems seem to only propagate either EIO
>> or ENOSPC, so I've followed suit in this patch.
>
> Do we?
Sometimes! :) I was referring to this:
static inline void mapping_set_error(struct address_space *mapping, int error)
{
if (unlikely(error)) {
if (error == -ENOSPC)
set_bit(AS_ENOSPC, &mapping->flags);
else
set_bit(AS_EIO, &mapping->flags);
}
}
> Just propagating some errors defintively seems odd.
Not really. read, write, etc only expect a subset of errnos to be
returned. The goal was not to leak kernel-internal or unexpected error
numbers to userspace, and I didn't think I would be able to successfully
audit all code paths that lead here. So, I opted for a more
conservative patch that just allows one more errno through.
> Even if we do we should have a central helper doing that mapping
> instead of opencoding it in various places.
OK. I would argue that the right place to filter out errno's would be
up in the vfs. I do wonder if I'm just being overly paranoid, though.
Al, do you have any opinions, here?
Cheers,
Jeff
