Re: [dm-devel] [PATCH v2 02/26] block: Add bio_advance()

[Kent Overstreet <koverstreet google com>]

On Thu, Sep 20, 2012 at 04:25:06PM -0700, Tejun Heo wrote:
> Hello,
> 
> On Thu, Sep 20, 2012 at 04:13:08PM -0700, Kent Overstreet wrote:
> > I just cut and pasted that from blk_update_request(), which is what the
> > next patch refactors...
> 
> Yeah, well, that was written when we didn't have WARNs.
> 
> > But yes it would be a bug. It gets converted to a BUG_ON() in a later
> > patch (not in this series), as this gets further abstracted into a
> > wrapper around bvec_advance_iter() which doesn't know about struct bio
> > (as bio integrity gets its own iterator).
> 
> WARN() generally preferable unless there's no way at all to continue.
> Storage layer could be a bit different if immediate danger for data
> corruption exists but the general consensus seems that we're too
> trigger happy with BUG_ON()s.

Yeah. Changed it to a WARN_ONCE().