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Date:   Tue, 28 Sep 2021 16:43:25 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Logan Gunthorpe <logang@deltatee.com>
Cc:     linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
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        Don Dutile <ddutile@redhat.com>,
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        Minturn Dave B <dave.b.minturn@intel.com>,
        Jason Ekstrand <jason@jlekstrand.net>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Xiong Jianxin <jianxin.xiong@intel.com>,
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        Robin Murphy <robin.murphy@arm.com>,
        Martin Oliveira <martin.oliveira@eideticom.com>,
        Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Subject: Re: [PATCH v3 12/20] RDMA/rw: use dma_map_sgtable()
Message-ID: <20210928194325.GS3544071@ziepe.ca>
References: <20210916234100.122368-1-logang@deltatee.com>
 <20210916234100.122368-13-logang@deltatee.com>
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On Thu, Sep 16, 2021 at 05:40:52PM -0600, Logan Gunthorpe wrote:
> dma_map_sg() now supports the use of P2PDMA pages so pci_p2pdma_map_sg()
> is no longer necessary and may be dropped.
> 
> Switch to the dma_map_sgtable() interface which will allow for better
> error reporting if the P2PDMA pages are unsupported.
> 
> The change to sgtable also appears to fix a couple subtle error path
> bugs:
> 
>   - In rdma_rw_ctx_init(), dma_unmap would be called with an sg
>     that could have been incremented from the original call, as
>     well as an nents that was not the original number of nents
>     called when mapped.
>   - Similarly in rdma_rw_ctx_signature_init, both sg and prot_sg
>     were unmapped with the incorrect number of nents.

Those bugs should definately get fixed.. I might extract the sgtable
conversion into a stand alone patch to do it.

But as it is, this looks fine

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason