From cbaf58032efca401834518b905f528ac912449e4 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 7 Feb 2017 11:58:15 -0500 Subject: [PATCH] svcrdma: Another sendto chunk list parsing update Commit 5fdca6531434 ("svcrdma: Renovate sendto chunk list parsing") missed a spot. svc_rdma_xdr_get_reply_hdr_len() also assumes the Write list has only one Write chunk. There's no harm in making this code more general. Signed-off-by: Chuck Lever Reviewed-by: Christoph Hellwig Signed-off-by: J. Bruce Fields --- include/linux/sunrpc/rpc_rdma.h | 9 +++++ include/linux/sunrpc/svc_rdma.h | 2 +- net/sunrpc/xprtrdma/svc_rdma_marshal.c | 49 ++++++++++++++------------ net/sunrpc/xprtrdma/svc_rdma_sendto.c | 3 +- 4 files changed, 38 insertions(+), 25 deletions(-) diff --git a/include/linux/sunrpc/rpc_rdma.h b/include/linux/sunrpc/rpc_rdma.h index cfda6adcf33c..245fc59b7324 100644 --- a/include/linux/sunrpc/rpc_rdma.h +++ b/include/linux/sunrpc/rpc_rdma.h @@ -109,6 +109,15 @@ struct rpcrdma_msg { } rm_body; }; +/* + * XDR sizes, in quads + */ +enum { + rpcrdma_fixed_maxsz = 4, + rpcrdma_segment_maxsz = 4, + rpcrdma_readchunk_maxsz = 2 + rpcrdma_segment_maxsz, +}; + /* * Smallest RPC/RDMA header: rm_xid through rm_type, then rm_nochunks */ diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 757fb963696c..551c51816352 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -218,7 +218,7 @@ extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *, struct rpcrdma_msg *, struct rpcrdma_msg *, enum rpcrdma_proc); -extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *); +extern unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp); /* svc_rdma_recvfrom.c */ extern int svc_rdma_recvfrom(struct svc_rqst *); diff --git a/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/net/sunrpc/xprtrdma/svc_rdma_marshal.c index 0ba9887f3e22..4e7203439e2f 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_marshal.c +++ b/net/sunrpc/xprtrdma/svc_rdma_marshal.c @@ -260,32 +260,35 @@ int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt, return (int)((unsigned long)va - (unsigned long)startp); } -int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp) +/** + * svc_rdma_xdr_get_reply_hdr_length - Get length of Reply transport header + * @rdma_resp: buffer containing Reply transport header + * + * Returns length of transport header, in bytes. + */ +unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp) { - struct rpcrdma_write_array *wr_ary; + unsigned int nsegs; + __be32 *p; - /* There is no read-list in a reply */ + p = rdma_resp; - /* skip write list */ - wr_ary = (struct rpcrdma_write_array *) - &rmsgp->rm_body.rm_chunks[1]; - if (wr_ary->wc_discrim) - wr_ary = (struct rpcrdma_write_array *) - &wr_ary->wc_array[be32_to_cpu(wr_ary->wc_nchunks)]. - wc_target.rs_length; - else - wr_ary = (struct rpcrdma_write_array *) - &wr_ary->wc_nchunks; - - /* skip reply array */ - if (wr_ary->wc_discrim) - wr_ary = (struct rpcrdma_write_array *) - &wr_ary->wc_array[be32_to_cpu(wr_ary->wc_nchunks)]; - else - wr_ary = (struct rpcrdma_write_array *) - &wr_ary->wc_nchunks; - - return (unsigned long) wr_ary - (unsigned long) rmsgp; + /* RPC-over-RDMA V1 replies never have a Read list. */ + p += rpcrdma_fixed_maxsz + 1; + + /* Skip Write list. */ + while (*p++ != xdr_zero) { + nsegs = be32_to_cpup(p++); + p += nsegs * rpcrdma_segment_maxsz; + } + + /* Skip Reply chunk. */ + if (*p++ != xdr_zero) { + nsegs = be32_to_cpup(p++); + p += nsegs * rpcrdma_segment_maxsz; + } + + return (unsigned long)p - (unsigned long)rdma_resp; } void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks) diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index ad4d286a83c5..ba76f1617965 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -476,7 +476,8 @@ static int send_reply(struct svcxprt_rdma *rdma, /* Prepare the SGE for the RPCRDMA Header */ ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey; - ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp); + ctxt->sge[0].length = + svc_rdma_xdr_get_reply_hdr_len((__be32 *)rdma_resp); ctxt->sge[0].addr = ib_dma_map_page(rdma->sc_cm_id->device, page, 0, ctxt->sge[0].length, DMA_TO_DEVICE); -- 2.45.2