From ab1394ee7a110190c2ea38e1f1b72737daa10f20 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 13 Mar 2020 10:42:10 -0400 Subject: svcrdma: Refactor the RDMA Write path Refactor for subsequent changes. Constify the xdr_buf argument to ensure the code here does not modify it, and to enable callers to pass in a "const struct xdr_buf *". At the same time, rename the helper functions, which emit RDMA Writes, not RDMA Sends, and add documenting comments. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/svc_rdma_rw.c | 56 ++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 21 deletions(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c index aeed4e200949..a75f8a133bef 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c @@ -495,27 +495,42 @@ out_overflow: return -E2BIG; } -/* Send one of an xdr_buf's kvecs by itself. To send a Reply - * chunk, the whole RPC Reply is written back to the client. - * This function writes either the head or tail of the xdr_buf - * containing the Reply. +/** + * svc_rdma_iov_write - Construct RDMA Writes from an iov + * @info: pointer to write arguments + * @iov: kvec to write + * + * Returns: + * On succes, returns zero + * %-E2BIG if the client-provided Write chunk is too small + * %-ENOMEM if a resource has been exhausted + * %-EIO if an rdma-rw error occurred */ -static int svc_rdma_send_xdr_kvec(struct svc_rdma_write_info *info, - struct kvec *vec) +static int svc_rdma_iov_write(struct svc_rdma_write_info *info, + const struct kvec *iov) { - info->wi_base = vec->iov_base; + info->wi_base = iov->iov_base; return svc_rdma_build_writes(info, svc_rdma_vec_to_sg, - vec->iov_len); + iov->iov_len); } -/* Send an xdr_buf's page list by itself. A Write chunk is just - * the page list. A Reply chunk is @xdr's head, page list, and - * tail. This function is shared between the two types of chunk. +/** + * svc_rdma_pages_write - Construct RDMA Writes from pages + * @info: pointer to write arguments + * @xdr: xdr_buf with pages to write + * @offset: offset into the content of @xdr + * @length: number of bytes to write + * + * Returns: + * On succes, returns zero + * %-E2BIG if the client-provided Write chunk is too small + * %-ENOMEM if a resource has been exhausted + * %-EIO if an rdma-rw error occurred */ -static int svc_rdma_send_xdr_pagelist(struct svc_rdma_write_info *info, - struct xdr_buf *xdr, - unsigned int offset, - unsigned long length) +static int svc_rdma_pages_write(struct svc_rdma_write_info *info, + const struct xdr_buf *xdr, + unsigned int offset, + unsigned long length) { info->wi_xdr = xdr; info->wi_next_off = offset - xdr->head[0].iov_len; @@ -552,7 +567,7 @@ int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma, __be32 *wr_ch, if (!info) return -ENOMEM; - ret = svc_rdma_send_xdr_pagelist(info, xdr, offset, length); + ret = svc_rdma_pages_write(info, xdr, offset, length); if (ret < 0) goto out_err; @@ -592,7 +607,7 @@ int svc_rdma_send_reply_chunk(struct svcxprt_rdma *rdma, if (!info) return -ENOMEM; - ret = svc_rdma_send_xdr_kvec(info, &xdr->head[0]); + ret = svc_rdma_iov_write(info, &xdr->head[0]); if (ret < 0) goto out_err; consumed = xdr->head[0].iov_len; @@ -601,16 +616,15 @@ int svc_rdma_send_reply_chunk(struct svcxprt_rdma *rdma, * client did not provide Write chunks. */ if (!rctxt->rc_write_list && xdr->page_len) { - ret = svc_rdma_send_xdr_pagelist(info, xdr, - xdr->head[0].iov_len, - xdr->page_len); + ret = svc_rdma_pages_write(info, xdr, xdr->head[0].iov_len, + xdr->page_len); if (ret < 0) goto out_err; consumed += xdr->page_len; } if (xdr->tail[0].iov_len) { - ret = svc_rdma_send_xdr_kvec(info, &xdr->tail[0]); + ret = svc_rdma_iov_write(info, &xdr->tail[0]); if (ret < 0) goto out_err; consumed += xdr->tail[0].iov_len; -- cgit v1.2.3