From 5fdca6531434c1c1b2d584873afdda52e5ad448c Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 29 Nov 2016 11:04:42 -0500 Subject: [PATCH] svcrdma: Renovate sendto chunk list parsing The current sendto code appears to support clients that provide only one of a Read list, a Write list, or a Reply chunk. My reading of that code is that it doesn't support the following cases: - Read list + Write list - Read list + Reply chunk - Write list + Reply chunk - Read list + Write list + Reply chunk The protocol allows more than one Read or Write chunk in those lists. Some clients do send a Read list and Reply chunk simultaneously. NFSv4 WRITE uses a Read list for the data payload, and a Reply chunk because the GETATTR result in the reply can contain a large object like an ACL. Generalize one of the sendto code paths needed to support all of the above cases, and attempt to ensure that only one pass is done through the RPC Call's transport header to gather chunk list information for building the reply. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields --- include/linux/sunrpc/svc_rdma.h | 2 - net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 14 ++++ net/sunrpc/xprtrdma/svc_rdma_sendto.c | 92 +++++++------------------ 3 files changed, 39 insertions(+), 69 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index cc3ae16eac68..6aef63b9a669 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -236,8 +236,6 @@ extern int rdma_read_chunk_frmr(struct svcxprt_rdma *, struct svc_rqst *, extern int svc_rdma_map_xdr(struct svcxprt_rdma *, struct xdr_buf *, 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 *); extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *, int); diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index ad1df979b3f0..873c2a938d35 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -415,6 +415,20 @@ done: return 1; } +/* Returns the address of the first read chunk or if no read chunk + * is present + */ +static struct rpcrdma_read_chunk * +svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp) +{ + struct rpcrdma_read_chunk *ch = + (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; + + if (ch->rc_discrim == xdr_zero) + return NULL; + return ch; +} + static int rdma_read_chunks(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp, struct svc_rqst *rqstp, diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index f5a91edcd233..0a58d4062f2f 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -153,76 +153,35 @@ static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt, return dma_addr; } -/* Returns the address of the first read chunk or if no read chunk - * is present +/* Parse the RPC Call's transport header. */ -struct rpcrdma_read_chunk * -svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp) +static void svc_rdma_get_write_arrays(struct rpcrdma_msg *rmsgp, + struct rpcrdma_write_array **write, + struct rpcrdma_write_array **reply) { - struct rpcrdma_read_chunk *ch = - (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; + __be32 *p; - if (ch->rc_discrim == xdr_zero) - return NULL; - return ch; -} + p = (__be32 *)&rmsgp->rm_body.rm_chunks[0]; -/* Returns the address of the first read write array element or - * if no write array list is present - */ -static struct rpcrdma_write_array * -svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp) -{ - if (rmsgp->rm_body.rm_chunks[0] != xdr_zero || - rmsgp->rm_body.rm_chunks[1] == xdr_zero) - return NULL; - return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1]; -} + /* Read list */ + while (*p++ != xdr_zero) + p += 5; -/* Returns the address of the first reply array element or if no - * reply array is present - */ -static struct rpcrdma_write_array * -svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp, - struct rpcrdma_write_array *wr_ary) -{ - struct rpcrdma_read_chunk *rch; - struct rpcrdma_write_array *rp_ary; - - /* XXX: Need to fix when reply chunk may occur with read list - * and/or write list. - */ - if (rmsgp->rm_body.rm_chunks[0] != xdr_zero || - rmsgp->rm_body.rm_chunks[1] != xdr_zero) - return NULL; - - rch = svc_rdma_get_read_chunk(rmsgp); - if (rch) { - while (rch->rc_discrim != xdr_zero) - rch++; - - /* The reply chunk follows an empty write array located - * at 'rc_position' here. The reply array is at rc_target. - */ - rp_ary = (struct rpcrdma_write_array *)&rch->rc_target; - goto found_it; + /* Write list */ + if (*p != xdr_zero) { + *write = (struct rpcrdma_write_array *)p; + while (*p++ != xdr_zero) + p += 1 + be32_to_cpu(*p) * 4; + } else { + *write = NULL; + p++; } - if (wr_ary) { - int chunk = be32_to_cpu(wr_ary->wc_nchunks); - - rp_ary = (struct rpcrdma_write_array *) - &wr_ary->wc_array[chunk].wc_target.rs_length; - goto found_it; - } - - /* No read list, no write list */ - rp_ary = (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[2]; - - found_it: - if (rp_ary->wc_discrim == xdr_zero) - return NULL; - return rp_ary; + /* Reply chunk */ + if (*p != xdr_zero) + *reply = (struct rpcrdma_write_array *)p; + else + *reply = NULL; } /* RPC-over-RDMA Version One private extension: Remote Invalidation. @@ -244,8 +203,8 @@ static u32 svc_rdma_get_inv_rkey(struct rpcrdma_msg *rdma_argp, inv_rkey = 0; - rd_ary = svc_rdma_get_read_chunk(rdma_argp); - if (rd_ary) { + rd_ary = (struct rpcrdma_read_chunk *)&rdma_argp->rm_body.rm_chunks[0]; + if (rd_ary->rc_discrim != xdr_zero) { inv_rkey = be32_to_cpu(rd_ary->rc_target.rs_handle); goto out; } @@ -622,8 +581,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) * places this at the start of page 0. */ rdma_argp = page_address(rqstp->rq_pages[0]); - wr_ary = svc_rdma_get_write_array(rdma_argp); - rp_ary = svc_rdma_get_reply_array(rdma_argp, wr_ary); + svc_rdma_get_write_arrays(rdma_argp, &wr_ary, &rp_ary); inv_rkey = 0; if (rdma->sc_snd_w_inv)