From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ming Lei <ming.lei@redhat.com>
Date: Tue, 22 Jan 2019 10:01:30 +0800
Subject: [Cluster-devel] [PATCH V14 00/18] block: support multi-page bvec
In-Reply-To: <61dfaa1e-e7bf-75f1-410b-ed32f97d0782@grimberg.me>
References: <20190121081805.32727-1-ming.lei@redhat.com>
	<61dfaa1e-e7bf-75f1-410b-ed32f97d0782@grimberg.me>
Message-ID: <20190122020128.GB2490@ming.t460p>
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On Mon, Jan 21, 2019 at 01:43:21AM -0800, Sagi Grimberg wrote:
> 
> > V14:
> > 	- drop patch(patch 4 in V13) for renaming bvec helpers, as suggested by Jens
> > 	- use mp_bvec_* as multi-page bvec helper name
> > 	- fix one build issue, which is caused by missing one converion of
> > 	bio_for_each_segment_all in fs/gfs2
> > 	- fix one 32bit ARCH specific issue caused by segment boundary mask
> > 	overflow
> 
> Hey Ming,
> 
> So is nvme-tcp also affected here? The only point where I see nvme-tcp
> can be affected is when initializing a bvec iter using bio_segments() as
> everywhere else we use iters which should transparently work..
> 
> I see that loop was converted, does it mean that nvme-tcp needs to
> call something like?
> --
> 	bio_for_each_mp_bvec(bv, bio, iter)
> 		nr_bvecs++;

bio_for_each_segment()/bio_segments() still works, just not as efficient
as bio_for_each_mp_bvec() given each multi-page bvec(very similar with scatterlist)
is returned in each loop.

I don't look at nvme-tcp code yet. But if nvme-tcp supports this way,
it can benefit from bio_for_each_mp_bvec().

Thanks,
Ming