From patchwork Mon Aug 14 14:32:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13352990 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B45BCBA34 for ; Mon, 14 Aug 2023 14:32:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C10BEC433C9; Mon, 14 Aug 2023 14:32:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692023538; bh=90QNq6jUBs43bpm8ggLivszh1cU+3BB9qLpGVoSmrEo=; h=From:Date:Subject:To:Cc:From; b=YtAh5nNsuYkFuxI4zL8RsiEspCmnoEwuiAm5cQ/bZ7kU7MhWtQwiZn5DujppZvYin PcM0ayv2HA0o7Wv1u82wm7W9X8lPp0LW42ZyVMks0E7m07VI6cS4lX+yWZInrjkGHO y+qizDhSg9pIaGjCZ0cAQQzNMdGzAvXw9VSi3i5r0xhGliex+f0j7/sbB9dtnMRZ7Z abSls76wUWKXw5dAJve1cyMsrgR0m9zXvGvTweROgiispVVGZNMl5rEoJImS3/Ujp4 gY2ov9sC3Nsn4GwD64E+GGW+d9UgvUAzDTQX2/vij7C1s87H6APGwjznKYcK76FbAi jbJDKpCWpl1jA== From: Jeff Layton Date: Mon, 14 Aug 2023 10:32:08 -0400 Subject: [PATCH] sunrpc: account for xdr->page_base in xdr_alloc_bvec Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20230814-sendpage-v1-1-d551b0d7f870@kernel.org> X-B4-Tracking: v=1; b=H4sIAOc62mQC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDI2MDC0MT3eLUvJSCRKB4koGJhblJamqKkYmlElB5QVFqWmYF2Kjo2NpaAIk 6mylaAAAA To: David Howells , Trond Myklebust , Anna Schumaker , Chuck Lever , Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: linux-nfs@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jeff Layton X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1876; i=jlayton@kernel.org; h=from:subject:message-id; bh=90QNq6jUBs43bpm8ggLivszh1cU+3BB9qLpGVoSmrEo=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBk2jrwoUKjYoT7AqXvTuTJcLJ8Gy0jY9C6foHJg 6Dc79Ikx1eJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZNo68AAKCRAADmhBGVaC Fbh1EAC9EaYqlhjwxIGjMyt+X9y98zc44/cp0SVY2HEbsQqc9nQ8EXyrEujni37UZq4E9tBNsUH 8n+DfAIjNC5OXciefDqQAz+atvdY8jlQXXXQvLU9i7ubP7IrlFxEe1VATHUwEorvnONGBoKuPDq /B27fufj2RU4RGeY88I78MqiCd9Yj1Sk4Dc8nuU1w5fqatsekhY6qS9fWKTMEDKeKlWe9JNT6mH Yl4F25ymwWdvAV50c6kRIMEy92Wk0yJ31cU0BS16vXleOb7gmy/pWMP8UQDkf71BpKM6sW32e4h Nu5/kxCMnY4N5GYTTkEZy3XRBhpvuIIzdhcug/HCCQjdR0X1DAMCVtGm1hUquJfxgOQtUK8YgrU QwXapfRPyOLrH5JCZHe6Es+Mi/Z6LyO7S8f71Dafv1NIRXdI34rrdR9mc3xRsaWvzIDSSoCeDHR xBGalvQ7YYZIonjSUZX3AotKv/Ta0+UwDhEJ7c5OFz4WtyvbUr3i0E7Kt6g55xMX6HzLik2UbMU +Rp0v/c2u9vMydZ1kaFCLgiOqB8sFpxUCLIIvm8DYd/oe8rTlkXOGcRhWomNNas3OZ9IRlU8jp9 LmK5yziEtuxi+Dmo31dh15HJChFZ9DdaCR5Njy3O0rsc0r7aMtrAZFUkDOaRJiaK+J0neAbZYxz Rs71yi3RW2TpIKw== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 X-Patchwork-Delegate: kuba@kernel.org I've been seeing a regression in mainline (v6.5-rc) kernels where unaligned reads were returning corrupt data. 9d96acbc7f37 added a routine to allocate and populate a bvec array that can be used to back an iov_iter. When it does this, it always sets the offset in the first bvec to zero, even when the xdr->page_base is non-zero. The old code in svc_tcp_sendmsg used to account for this, as it was sending the pages one at a time anyway, but now that we just hand the iov to the network layer, we need to ensure that the bvecs are properly initialized. Fix xdr_alloc_bvec to set the offset in the first bvec to the offset indicated by xdr->page_base, and then 0 in all subsequent bvecs. Fixes: 9d96acbc7f37 ("SUNRPC: Add a bvec array to struct xdr_buf for use with iovec_iter()") Signed-off-by: Jeff Layton --- NB: This is only lightly tested so far, but it seems to fix the pynfs regressions I've been seeing. --- net/sunrpc/xdr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- base-commit: 2ccdd1b13c591d306f0401d98dedc4bdcd02b421 change-id: 20230814-sendpage-b04874eed249 Best regards, diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 2a22e78af116..d0f5fc8605b8 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -144,6 +144,7 @@ int xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp) { size_t i, n = xdr_buf_pagecount(buf); + unsigned int offset = offset_in_page(buf->page_base); if (n != 0 && buf->bvec == NULL) { buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp); @@ -151,7 +152,8 @@ xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp) return -ENOMEM; for (i = 0; i < n; i++) { bvec_set_page(&buf->bvec[i], buf->pages[i], PAGE_SIZE, - 0); + offset); + offset = 0; } } return 0;