From 65b80179f9b8171b74625febf3457f41e792fa23 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 29 Jun 2016 13:55:06 -0400 Subject: xprtrdma: No direct data placement with krb5i and krb5p Direct data placement is not allowed when using flavors that guarantee integrity or privacy. When such security flavors are in effect, don't allow the use of Read and Write chunks for moving individual data items. All messages larger than the inline threshold are sent via Long Call or Long Reply. On my systems (CX-3 Pro on FDR), for small I/O operations, the use of Long messages adds only around 5 usecs of latency in each direction. Note that when integrity or encryption is used, the host CPU touches every byte in these messages. Even if it could be used, data movement offload doesn't buy much in this case. Signed-off-by: Chuck Lever Tested-by: Steve Wise Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/rpc_rdma.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'net/sunrpc/xprtrdma') diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index dac2990ae2f7..a47f170b20ef 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -570,6 +570,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) struct rpcrdma_req *req = rpcr_to_rdmar(rqst); enum rpcrdma_chunktype rtype, wtype; struct rpcrdma_msg *headerp; + bool ddp_allowed; ssize_t hdrlen; size_t rpclen; __be32 *iptr; @@ -586,6 +587,13 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_max_requests); headerp->rm_type = rdma_msg; + /* When the ULP employs a GSS flavor that guarantees integrity + * or privacy, direct data placement of individual data items + * is not allowed. + */ + ddp_allowed = !(rqst->rq_cred->cr_auth->au_flags & + RPCAUTH_AUTH_DATATOUCH); + /* * Chunks needed for results? * @@ -597,7 +605,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) */ if (rpcrdma_results_inline(r_xprt, rqst)) wtype = rpcrdma_noch; - else if (rqst->rq_rcv_buf.flags & XDRBUF_READ) + else if (ddp_allowed && rqst->rq_rcv_buf.flags & XDRBUF_READ) wtype = rpcrdma_writech; else wtype = rpcrdma_replych; @@ -620,7 +628,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) rtype = rpcrdma_noch; rpcrdma_inline_pullup(rqst); rpclen = rqst->rq_svec[0].iov_len; - } else if (rqst->rq_snd_buf.flags & XDRBUF_WRITE) { + } else if (ddp_allowed && rqst->rq_snd_buf.flags & XDRBUF_WRITE) { rtype = rpcrdma_readch; rpclen = rqst->rq_svec[0].iov_len; rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf); -- cgit v1.2.3