Re: [RFC PATCH 4/4] nfs: allow P2PDMA in direct I/O path

Christoph Hellwig
2026-04-02T05:05:42Z

On Wed, Apr 01, 2026 at 07:45:00PM +0000, Pranjal Shrivastava wrote:
> Migrate the NFS Direct I/O path from the legacy iov_iter_get_pages_alloc2()
> API to the modern iov_iter_extract_pages() API. This migration enables
> support for PCI Peer-to-Peer DMA (P2PDMA) by allowing the setting the
> ITER_ALLOW_P2PDMA flag.
>
> Pass ITER_ALLOW_P2PDMA to iov_iter_extract_pages() only if the local
> mount indicates support via the NFS_CAP_P2PDMA capability bit (detected
> at mount time for RDMA transports).

Please split theconversion to iov_iter_extract_pages into a separate
preparation patch, and even series. That is a long overdue change
that fixes potential data corruption in XFS.