Commit 2fcc213a authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

xprtrdma: Fix large NFS SYMLINK calls 



Repair how rpcrdma_marshal_req() chooses which RDMA message type
to use for large non-WRITE operations so that it picks RDMA_NOMSG
in the correct situations, and sets up the marshaling logic to
SEND only the RPC/RDMA header.

Large NFSv2 SYMLINK requests now use RDMA_NOMSG calls. The Linux NFS
server XDR decoder for NFSv2 SYMLINK does not handle having the
pathname argument arrive in a separate buffer. The decoder could be
fixed, but this is simpler and RDMA_NOMSG can be used in a variety
of other situations.

Ensure that the Linux client continues to use "RDMA_MSG + read
list" when sending large NFSv3 SYMLINK requests, which is more
efficient than using RDMA_NOMSG.

Large NFSv4 CREATE(NF4LNK) requests are changed to use "RDMA_MSG +
read list" just like NFSv3 (see Section 5 of RFC 5667). Before,
these did not work at all.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Tested-by: default avatarDevesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 677eb17e

fs/nfs/nfs3xdr.c

+1 −0
Original line number Diff line number Diff line
@@ -1103,6 +1103,7 @@ static void nfs3_xdr_enc_symlink3args(struct rpc_rqst *req, 
{

	encode_diropargs3(xdr, args->fromfh, args->fromname, args->fromlen);

	encode_symlinkdata3(xdr, args);

	xdr->buf->flags |= XDRBUF_WRITE;

}



/*

fs/nfs/nfs4xdr.c

+3 −1
Original line number Diff line number Diff line
@@ -1154,7 +1154,9 @@ static void encode_create(struct xdr_stream *xdr, const struct nfs4_create_arg * 
	case NF4LNK:

		p = reserve_space(xdr, 4);

		*p = cpu_to_be32(create->u.symlink.len);

		xdr_write_pages(xdr, create->u.symlink.pages, 0, create->u.symlink.len);

		xdr_write_pages(xdr, create->u.symlink.pages, 0,

				create->u.symlink.len);

		xdr->buf->flags |= XDRBUF_WRITE;

		break;



	case NF4BLK: case NF4CHR:

net/sunrpc/xprtrdma/rpc_rdma.c

+16 −9
Original line number Diff line number Diff line
@@ -475,21 +475,24 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) 
	 *

	 * o If the total request is under the inline threshold, all ops

	 *   are sent as inline.

	 * o Large non-write ops are sent with the entire message as a

	 *   single read chunk (protocol 0-position special case).

	 * o Large write ops transmit data as read chunk(s), header as

	 *   inline.

	 * o Large non-write ops are sent with the entire message as a

	 *   single read chunk (protocol 0-position special case).

	 *

	 * Note: the NFS code sending down multiple argument segments

	 * implies the op is a write.

	 * TBD check NFSv4 setacl

	 * This assumes that the upper layer does not present a request

	 * that both has a data payload, and whose non-data arguments

	 * by themselves are larger than the inline threshold.

	 */

	if (rpcrdma_args_inline(rqst))

	if (rpcrdma_args_inline(rqst)) {

		rtype = rpcrdma_noch;

	else if (rqst->rq_snd_buf.page_len == 0)

		rtype = rpcrdma_areadch;

	else

	} else if (rqst->rq_snd_buf.flags & XDRBUF_WRITE) {

		rtype = rpcrdma_readch;

	} else {

		headerp->rm_type = htonl(RDMA_NOMSG);

		rtype = rpcrdma_areadch;

		rpclen = 0;

	}



	/* The following simplification is not true forever */

	if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
@@ -546,6 +549,10 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) 
	req->rl_send_iov[0].length = hdrlen;

	req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf);



	req->rl_niovs = 1;

	if (rtype == rpcrdma_areadch)

		return 0;



	req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);

	req->rl_send_iov[1].length = rpclen;

	req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);

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