Re: [PATCH 1/2] blkdev: fix merge_bvec_fn return value checks

[Jens Axboe <jens.axboe@oracle.com>]

On Wed, Mar 03 2010, Dmitry Monakhov wrote:
> Jens Axboe <jens.axboe@oracle.com> writes:
> 
> > On Wed, Mar 03 2010, Dmitry Monakhov wrote:
> >> Jens Axboe <jens.axboe@oracle.com> writes:
> >> 
> >> > On Sat, Feb 27 2010, Dmitry Monakhov wrote:
> >> >> merge_bvec_fn() returns bvec->bv_len on success. So we have to check
> >> >> against this value. But in case of fs_optimization merge we compare
> >> >> with wrong value. This patch must be included in
> >> >>  b428cd6da7e6559aca69aa2e3a526037d3f20403
> >> >> But accidentally i've forgot to add this in the initial patch.
> >> >> To make things straight let's replace all such checks.
> >> >> In fact this makes code easy to understand.
> >> >
> >> > Agree, applied.
> >> Ohh.. as you already know this patch break dm-layer. Sorry.
> >> This is because dm->merge may return more than requested. So correct
> >> check must test against less what requested. Correct patch attached.
> >
> > Have you tested this with dm and md (ie actual users of the merge_bvec
> > functionality) this time?
> Yes. This time both md and dm are ok.

Good, I'll queue it up for testing.

-- 
Jens Axboe