From d2727cefff0204c3074a10e3ad2e1b5c9dfb986c Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Sun, 4 Feb 2024 18:17:41 -0500 Subject: svcrdma: Post WRs for Write chunks in svc_rdma_sendto() Refactor to eventually enable svcrdma to post the Write WRs for each RPC response using the same ib_post_send() as the Send WR (ie, as a single WR chain). svc_rdma_result_payload (originally svc_rdma_read_payload) was added so that the upper layer XDR encoder could identify a range of bytes to be possibly conveyed by RDMA (if a Write chunk was provided by the client). The purpose of commit f6ad77590a5d ("svcrdma: Post RDMA Writes while XDR encoding replies") was to post as much of the result payload outside of svc_rdma_sendto() as possible because svc_rdma_sendto() used to be called with the xpt_mutex held. However, since commit ca4faf543a33 ("SUNRPC: Move xpt_mutex into socket xpo_sendto methods"), the xpt_mutex is no longer held when calling svc_rdma_sendto(). Thus, that benefit is no longer an issue. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/svc_rdma_rw.c | 56 +++++++++++++++++++++++------------ net/sunrpc/xprtrdma/svc_rdma_sendto.c | 30 +++++++------------ 2 files changed, 48 insertions(+), 38 deletions(-) (limited to 'net') diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c index 2b25edc6c73c..40797114d50a 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c @@ -601,47 +601,65 @@ static int svc_rdma_xb_write(const struct xdr_buf *xdr, void *data) return xdr->len; } -/** - * svc_rdma_send_write_chunk - Write all segments in a Write chunk - * @rdma: controlling RDMA transport - * @chunk: Write chunk provided by the client - * @xdr: xdr_buf containing the data payload - * - * Returns a non-negative number of bytes the chunk consumed, or - * %-E2BIG if the payload was larger than the Write chunk, - * %-EINVAL if client provided too many segments, - * %-ENOMEM if rdma_rw context pool was exhausted, - * %-ENOTCONN if posting failed (connection is lost), - * %-EIO if rdma_rw initialization failed (DMA mapping, etc). - */ -int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma, - const struct svc_rdma_chunk *chunk, - const struct xdr_buf *xdr) +static int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma, + const struct svc_rdma_chunk *chunk, + const struct xdr_buf *xdr) { struct svc_rdma_write_info *info; struct svc_rdma_chunk_ctxt *cc; + struct xdr_buf payload; int ret; + if (xdr_buf_subsegment(xdr, &payload, chunk->ch_position, + chunk->ch_payload_length)) + return -EMSGSIZE; + info = svc_rdma_write_info_alloc(rdma, chunk); if (!info) return -ENOMEM; cc = &info->wi_cc; - ret = svc_rdma_xb_write(xdr, info); - if (ret != xdr->len) + ret = svc_rdma_xb_write(&payload, info); + if (ret != payload.len) goto out_err; trace_svcrdma_post_write_chunk(&cc->cc_cid, cc->cc_sqecount); ret = svc_rdma_post_chunk_ctxt(rdma, cc); if (ret < 0) goto out_err; - return xdr->len; + return 0; out_err: svc_rdma_write_info_free(info); return ret; } +/** + * svc_rdma_send_write_list - Send all chunks on the Write list + * @rdma: controlling RDMA transport + * @rctxt: Write list provisioned by the client + * @xdr: xdr_buf containing an RPC Reply message + * + * Returns zero on success, or a negative errno if one or more + * Write chunks could not be sent. + */ +int svc_rdma_send_write_list(struct svcxprt_rdma *rdma, + const struct svc_rdma_recv_ctxt *rctxt, + const struct xdr_buf *xdr) +{ + struct svc_rdma_chunk *chunk; + int ret; + + pcl_for_each_chunk(chunk, &rctxt->rc_write_pcl) { + if (!chunk->ch_payload_length) + break; + ret = svc_rdma_send_write_chunk(rdma, chunk, xdr); + if (ret < 0) + return ret; + } + return 0; +} + /** * svc_rdma_prepare_reply_chunk - Construct WR chain for writing the Reply chunk * @rdma: controlling RDMA transport diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 6dfd2232ce5b..bb5436b719e0 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -1013,6 +1013,10 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) if (!p) goto put_ctxt; + ret = svc_rdma_send_write_list(rdma, rctxt, &rqstp->rq_res); + if (ret < 0) + goto put_ctxt; + rc_size = 0; if (!pcl_is_empty(&rctxt->rc_reply_pcl)) { ret = svc_rdma_prepare_reply_chunk(rdma, &rctxt->rc_write_pcl, @@ -1064,45 +1068,33 @@ drop_connection: /** * svc_rdma_result_payload - special processing for a result payload - * @rqstp: svc_rqst to operate on - * @offset: payload's byte offset in @xdr + * @rqstp: RPC transaction context + * @offset: payload's byte offset in @rqstp->rq_res * @length: size of payload, in bytes * + * Assign the passed-in result payload to the current Write chunk, + * and advance to cur_result_payload to the next Write chunk, if + * there is one. + * * Return values: * %0 if successful or nothing needed to be done - * %-EMSGSIZE on XDR buffer overflow * %-E2BIG if the payload was larger than the Write chunk - * %-EINVAL if client provided too many segments - * %-ENOMEM if rdma_rw context pool was exhausted - * %-ENOTCONN if posting failed (connection is lost) - * %-EIO if rdma_rw initialization failed (DMA mapping, etc) */ int svc_rdma_result_payload(struct svc_rqst *rqstp, unsigned int offset, unsigned int length) { struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; struct svc_rdma_chunk *chunk; - struct svcxprt_rdma *rdma; - struct xdr_buf subbuf; - int ret; chunk = rctxt->rc_cur_result_payload; if (!length || !chunk) return 0; rctxt->rc_cur_result_payload = pcl_next_chunk(&rctxt->rc_write_pcl, chunk); + if (length > chunk->ch_length) return -E2BIG; - chunk->ch_position = offset; chunk->ch_payload_length = length; - - if (xdr_buf_subsegment(&rqstp->rq_res, &subbuf, offset, length)) - return -EMSGSIZE; - - rdma = container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt); - ret = svc_rdma_send_write_chunk(rdma, chunk, &subbuf); - if (ret < 0) - return ret; return 0; } -- cgit v1.2.3-70-g09d2