Re: [PATCH v2 5/5] dax: handle media errors in dax_do_io

[Jeff Moyer]

"hch@xxxxxxxxxxxxx" <hch@xxxxxxxxxxxxx> writes:

> On Sat, Apr 23, 2016 at 06:08:37PM +0000, Verma, Vishal L wrote:
>> direct_IO might fail with -EINVAL due to misalignment, or -ENOMEM due
>> to some allocation failing, and I thought we should return the original
>> -EIO in such cases so that the application doesn't lose the information
>> that the bad block is actually causing the error.
>
> EINVAL is a concern here.  Not due to the right error reported, but
> because it means your current scheme is fundamentally broken - we
> need to support I/O at any alignment for DAX I/O, and not fail due to
> alignbment concernes for a highly specific degraded case.
>
> I think this whole series need to go back to the drawing board as I
> don't think it can actually rely on using direct I/O as the EIO
> fallback.

The only callers of dax_do_io are direct_IO methods.

Cheers,
Jeff