From: Christoph Hellwig <hch@lst.de>
To: Chuck Lever <cel@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Jason Gunthorpe <jgg@nvidia.com>,
Leon Romanovsky <leon@kernel.org>, NeilBrown <neilb@ownmail.net>,
Jeff Layton <jlayton@kernel.org>,
Olga Kornievskaia <okorniev@redhat.com>,
Dai Ngo <dai.ngo@oracle.com>, Tom Talpey <tom@talpey.com>,
linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org,
Chuck Lever <chuck.lever@oracle.com>
Subject: Re: [PATCH v3 2/5] RDMA/core: use IOVA-based DMA mapping for bvec RDMA operations
Date: Mon, 26 Jan 2026 07:14:33 +0100 [thread overview]
Message-ID: <20260126061433.GA1638@lst.de> (raw)
In-Reply-To: <d70b5896-2de8-4417-a149-0fd1c55f4d2d@app.fastmail.com>
On Fri, Jan 23, 2026 at 10:04:07AM -0500, Chuck Lever wrote:
> On Fri, Jan 23, 2026, at 1:28 AM, Christoph Hellwig wrote:
> >> + /* Link all bvecs into the IOVA space */
> >> + link_iter = *iter;
> >> + while (link_iter.bi_size) {
> >> + struct bio_vec bv = mp_bvec_iter_bvec(bvec, link_iter);
> >> +
> >> + ret = dma_iova_link(dma_dev, &ctx->iova.state, bvec_phys(&bv),
> >> + mapped_len, bv.bv_len, dir, 0);
> >> + if (ret)
> >> + goto out_destroy;
> >> +
> >> + mapped_len += bv.bv_len;
> >> + bvec_iter_advance(bvec, &link_iter, bv.bv_len);
> >> + }
> >
> > Why is this using a local link_iter? We're not using iter later.
>
> I think we don't want to leak a partially-updated iter if the
> API call returns an error.
That's how all the block layer bvec_iter-based API work. The
functions consume the iter. If a caller needs to save it for
some reason, it stashes away a copy.
next prev parent reply other threads:[~2026-01-26 6:14 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-22 22:03 [PATCH v3 0/5] Add a bio_vec based API to core/rw.c Chuck Lever
2026-01-22 22:03 ` [PATCH v3 1/5] RDMA/core: add bio_vec based RDMA read/write API Chuck Lever
2026-01-23 6:26 ` Christoph Hellwig
2026-01-22 22:03 ` [PATCH v3 2/5] RDMA/core: use IOVA-based DMA mapping for bvec RDMA operations Chuck Lever
2026-01-23 6:28 ` Christoph Hellwig
2026-01-23 15:04 ` Chuck Lever
2026-01-26 6:14 ` Christoph Hellwig [this message]
2026-01-22 22:03 ` [PATCH v3 3/5] RDMA/core: add MR support for bvec-based " Chuck Lever
2026-01-23 6:36 ` Christoph Hellwig
2026-01-23 15:06 ` Chuck Lever
2026-01-26 6:17 ` Christoph Hellwig
2026-01-26 16:48 ` Chuck Lever
2026-01-23 16:47 ` Chuck Lever
2026-01-26 6:16 ` Christoph Hellwig
2026-01-22 22:04 ` [PATCH v3 4/5] RDMA/core: add rdma_rw_max_sge() helper for SQ sizing Chuck Lever
2026-01-23 6:36 ` Christoph Hellwig
2026-01-22 22:04 ` [PATCH v3 5/5] svcrdma: use bvec-based RDMA read/write API Chuck Lever
2026-01-23 6:04 ` [PATCH v3 0/5] Add a bio_vec based API to core/rw.c Zhu Yanjun
2026-01-23 14:13 ` Chuck Lever
2026-01-24 18:19 ` Zhu Yanjun
2026-01-26 17:13 ` Jason Gunthorpe
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