The NFS server's XDR encoders adds an XDR pad for content in the xdr_buf page list at the beginning of the xdr_buf's tail buffer. On RDMA transports, Write chunks are sent separately and without an XDR pad. If a Write chunk is being sent, strip off the pad in the tail buffer so that inline content following the Write chunk remains XDR-aligned when it is sent to the client. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=294 Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- include/linux/sunrpc/svc_rdma.h | 2 +- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 2 +- net/sunrpc/xprtrdma/svc_rdma_sendto.c | 22 +++++++++++++++++----- 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 5322fea..40b6785 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -224,7 +224,7 @@ extern int rdma_read_chunk_frmr(struct svcxprt_rdma *, struct svc_rqst *, /* svc_rdma_sendto.c */ extern int svc_rdma_map_xdr(struct svcxprt_rdma *, struct xdr_buf *, - struct svc_rdma_req_map *); + struct svc_rdma_req_map *, bool); extern int svc_rdma_sendto(struct svc_rqst *); extern struct rpcrdma_read_chunk * svc_rdma_get_read_chunk(struct rpcrdma_msg *); diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index 65a7c23..de39196 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -107,7 +107,7 @@ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, int ret; vec = svc_rdma_get_req_map(rdma); - ret = svc_rdma_map_xdr(rdma, sndbuf, vec); + ret = svc_rdma_map_xdr(rdma, sndbuf, vec, false); if (ret) goto out_err; diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 86fea5c..a8fab99 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -57,7 +57,8 @@ static u32 xdr_padsize(u32 len) int svc_rdma_map_xdr(struct svcxprt_rdma *xprt, struct xdr_buf *xdr, - struct svc_rdma_req_map *vec) + struct svc_rdma_req_map *vec, + bool write_chunk_present) { int sge_no; u32 sge_bytes; @@ -97,9 +98,20 @@ int svc_rdma_map_xdr(struct svcxprt_rdma *xprt, /* Tail SGE */ if (xdr->tail[0].iov_len) { - vec->sge[sge_no].iov_base = xdr->tail[0].iov_base; - vec->sge[sge_no].iov_len = xdr->tail[0].iov_len; - sge_no++; + unsigned char *base = xdr->tail[0].iov_base; + size_t len = xdr->tail[0].iov_len; + u32 xdr_pad = xdr_padsize(xdr->page_len); + + if (write_chunk_present && xdr_pad) { + base += xdr_pad; + len -= xdr_pad; + } + + if (len) { + vec->sge[sge_no].iov_base = base; + vec->sge[sge_no].iov_len = len; + sge_no++; + } } dprintk("svcrdma: %s: sge_no %d page_no %d " @@ -594,7 +606,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) ctxt = svc_rdma_get_context(rdma); ctxt->direction = DMA_TO_DEVICE; vec = svc_rdma_get_req_map(rdma); - ret = svc_rdma_map_xdr(rdma, &rqstp->rq_res, vec); + ret = svc_rdma_map_xdr(rdma, &rqstp->rq_res, vec, wr_ary != NULL); if (ret) goto err0; inline_bytes = rqstp->rq_res.len; -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
