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[68.61.232.219]) by smtp.gmail.com with ESMTPSA id t57sm15022328qtc.91.2020.06.29.07.53.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Jun 2020 07:53:39 -0700 (PDT) Received: from klimt.1015granger.net (klimt.1015granger.net [192.168.1.55]) by gateway.1015granger.net (8.14.7/8.14.7) with ESMTP id 05TErcGu006227; Mon, 29 Jun 2020 14:53:38 GMT Subject: [PATCH v1 2/4] SUNRPC: Add helpers for decoding list discriminators symbolically From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Mon, 29 Jun 2020 10:53:38 -0400 Message-ID: <20200629145338.15063.29487.stgit@klimt.1015granger.net> In-Reply-To: <20200629145150.15063.29447.stgit@klimt.1015granger.net> References: <20200629145150.15063.29447.stgit@klimt.1015granger.net> User-Agent: StGit/0.22-31-g4b47 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Use these helpers in a few spots to demonstrate their use. The remaining open-coded discriminator checks in rpcrdma will be addressed in subsequent patches. Signed-off-by: Chuck Lever --- include/linux/sunrpc/xdr.h | 26 ++++++++++++++++++++++++++ net/sunrpc/xprtrdma/rpc_rdma.c | 12 ++++++------ net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 17 ++++++++--------- 3 files changed, 40 insertions(+), 15 deletions(-) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 22c207b2425f..5a6a81b7cd9f 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -474,6 +474,32 @@ xdr_stream_encode_uint32_array(struct xdr_stream *xdr, return ret; } +/** + * xdr_item_is_absent - symbolically handle XDR discriminators + * @p: pointer to undecoded discriminator + * + * Return values: + * %true if the following XDR item is absent + * %false if the following XDR item is present + */ +static inline bool xdr_item_is_absent(const __be32 *p) +{ + return *p == xdr_zero; +} + +/** + * xdr_item_is_present - symbolically handle XDR discriminators + * @p: pointer to undecoded discriminator + * + * Return values: + * %true if the following XDR item is present + * %false if the following XDR item is absent + */ +static inline bool xdr_item_is_present(const __be32 *p) +{ + return *p != xdr_zero; +} + /** * xdr_stream_decode_u32 - Decode a 32-bit integer * @xdr: pointer to xdr_stream diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 935bbef2f7be..feecd1f55f18 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1133,11 +1133,11 @@ rpcrdma_is_bcall(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep) p = xdr_inline_decode(xdr, 0); /* Chunk lists */ - if (*p++ != xdr_zero) + if (xdr_item_is_present(p++)) return false; - if (*p++ != xdr_zero) + if (xdr_item_is_present(p++)) return false; - if (*p++ != xdr_zero) + if (xdr_item_is_present(p++)) return false; /* RPC header */ @@ -1215,7 +1215,7 @@ static int decode_read_list(struct xdr_stream *xdr) p = xdr_inline_decode(xdr, sizeof(*p)); if (unlikely(!p)) return -EIO; - if (unlikely(*p != xdr_zero)) + if (unlikely(xdr_item_is_present(p))) return -EIO; return 0; } @@ -1234,7 +1234,7 @@ static int decode_write_list(struct xdr_stream *xdr, u32 *length) p = xdr_inline_decode(xdr, sizeof(*p)); if (unlikely(!p)) return -EIO; - if (*p == xdr_zero) + if (xdr_item_is_absent(p)) break; if (!first) return -EIO; @@ -1256,7 +1256,7 @@ static int decode_reply_chunk(struct xdr_stream *xdr, u32 *length) return -EIO; *length = 0; - if (*p != xdr_zero) + if (xdr_item_is_present(p)) if (decode_write_chunk(xdr, length)) return -EIO; return 0; diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index c072ce61b393..5e78067889f3 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -419,7 +419,7 @@ static bool xdr_check_read_list(struct svc_rdma_recv_ctxt *rctxt) len = 0; first = true; - while (*p != xdr_zero) { + while (xdr_item_is_present(p)) { p = xdr_inline_decode(&rctxt->rc_stream, rpcrdma_readseg_maxsz * sizeof(*p)); if (!p) @@ -500,7 +500,7 @@ static bool xdr_check_write_list(struct svc_rdma_recv_ctxt *rctxt) if (!p) return false; rctxt->rc_write_list = p; - while (*p != xdr_zero) { + while (xdr_item_is_present(p)) { if (!xdr_check_write_chunk(rctxt, MAX_BYTES_WRITE_CHUNK)) return false; ++chcount; @@ -532,12 +532,11 @@ static bool xdr_check_reply_chunk(struct svc_rdma_recv_ctxt *rctxt) p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); if (!p) return false; - rctxt->rc_reply_chunk = p; - if (*p != xdr_zero) { + rctxt->rc_reply_chunk = NULL; + if (xdr_item_is_present(p)) { if (!xdr_check_write_chunk(rctxt, MAX_BYTES_SPECIAL_CHUNK)) return false; - } else { - rctxt->rc_reply_chunk = NULL; + rctxt->rc_reply_chunk = p; } return true; } @@ -568,7 +567,7 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, p += rpcrdma_fixed_maxsz; /* Read list */ - while (*p++ != xdr_zero) { + while (xdr_item_is_present(p++)) { p++; /* position */ if (inv_rkey == xdr_zero) inv_rkey = *p; @@ -578,7 +577,7 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, } /* Write list */ - while (*p++ != xdr_zero) { + while (xdr_item_is_present(p++)) { segcount = be32_to_cpup(p++); for (i = 0; i < segcount; i++) { if (inv_rkey == xdr_zero) @@ -590,7 +589,7 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, } /* Reply chunk */ - if (*p++ != xdr_zero) { + if (xdr_item_is_present(p++)) { segcount = be32_to_cpup(p++); for (i = 0; i < segcount; i++) { if (inv_rkey == xdr_zero)