Re: need SUNRPC TCP to receive into aligned pages [was: Re: [PATCH 1/6] NFSD: add the ability to enable use of RWF_DONTCACHE for all IO]

Christoph Hellwig
2025-06-13T05:39:03Z

On Thu, Jun 12, 2025 at 11:58:27AM -0400, Chuck Lever wrote:
> NFS/RDMA does this already. Let's not re-invent the wheel.

The other thing that fixes the problem (but also creates various others)
are the block/scsi/nvme layouts, which gurantee that all the data
transfers to the data device us block protocols that gets this right.
Well, unless you run them over TCP and still get the whole receive
side copy issue in the drivers, but at least the copied payload
is always aligned.