Re: [dm-devel] [PATCH v3 11/26] block: Add submit_bio_wait(), remove from md

[Kent Overstreet <koverstreet google com>]

On Tue, Oct 02, 2012 at 04:16:30PM -0400, Vivek Goyal wrote:
> On Tue, Oct 02, 2012 at 01:11:05PM -0700, Kent Overstreet wrote:
> > On Tue, Oct 02, 2012 at 03:41:32PM -0400, Vivek Goyal wrote:
> > > On Mon, Sep 24, 2012 at 03:34:51PM -0700, Kent Overstreet wrote:
> > > > Random cleanup - this code was duplicated and it's not really specific
> > > > to md.
> > > > 
> > > > Also added the ability to return the actual error code.
> > > 
> > > Who is going to make use of actual error code and why checking
> > > BIO_UPTODATE is not sufficient (as existing code is doing)?
> > 
> > Some things do, though it's not common and I forget where I saw it -
> > checking for -ENOTSUPPORTED vs. other stuff
> 
> May be we can introduce "submit_bio_ret" stuff when we find the actual
> user in the series. Justifying code change becomes easier. 

Eh, IMO as generic code it's just better/more sensible that way;
bio_endio() does pass an actual error code, so the sync version should
pass it up too. Otherwise it's a needless inconsistency.

Honestly I would prefer sticking an error field in struct bio. That'd be
useful for other things, too.