Re: [PATCH v2 6/7] md/raid1,raid10: skip futile retries on P2PDMA mapping failures

Logan Gunthorpe <[email protected]> Mon, 20 Jul 2026 10:49:03 -0600
Newsgroups org.kernel.vger.linux-raid,org.infradead.lists.linux-nvme,org.kernel.vger.linux-block,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pci,org.kernel.vger.linux-rdma
Message-ID <[email protected]>

On 2026-07-19 04:53, Mykola Marzhan wrote:
>  drivers/md/raid1.c  | 56 +++++++++++++++++++++++++++++++-----
>  drivers/md/raid1.h  |  2 ++
>  drivers/md/raid10.c | 69 ++++++++++++++++++++++++++++++++++++++-------
>  drivers/md/raid10.h |  2 ++

This is an intimidating and massive patch to review. I gotta second the
verbosity of the AI commit messages comment from Keith.

My eyes glazed over a bit. But one point is that maybe this could be
split into multiple patches: one patch introduces R1BIO_P2PDMA, one
patch for raid1 and another patch for raid10? That might make it a bit
more manageable.

Also, I'm not sure if it's possible without digging deeper but, instead
of adding a !p2pdma_unmappable check to every if() statement in the
raid*_end_write_request() functions, might it be possible to factor out
a helper function and return early from it? Maybe the helper could be
shared between raid10 and raid1 as they look very similar. The
differences between the two are minimal -- there might be a bug fix that
was applied to one that should be applied to both?

Thanks!

Logan