From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D284C63697 for ; Wed, 18 Nov 2020 22:19:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7646246DC for ; Wed, 18 Nov 2020 22:19:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="yWDYVJcl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726772AbgKRWTp (ORCPT ); Wed, 18 Nov 2020 17:19:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:43818 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726766AbgKRWTo (ORCPT ); Wed, 18 Nov 2020 17:19:44 -0500 Received: from leira.hammer.space (c-68-36-133-222.hsd1.mi.comcast.net [68.36.133.222]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EBBED246DE for ; Wed, 18 Nov 2020 22:19:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605737984; bh=LMsPRKUc8R5f02kJdlmcEoIQVAinQSQdnEY3g8Kb6K0=; h=From:To:Subject:Date:In-Reply-To:References:From; b=yWDYVJcllIqM1DRaMUs9f5sI2NJV9QvzlGgHSkC2di9I2PopU0OkkiLb+K+AA4l8W bcVL5km6xmLrfc7qNKr9/5ZZX66HM8viZfCpcUan6nxsly+zJjEx8QhweucrMfUKzz v4pGs1dpFQmRlbBjnYM0XI5iE5cpHKdjR3bZC9oI= From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH 2/3] NFS: Avoid copy of xdr padding in readlink, layoutget and getxattr Date: Wed, 18 Nov 2020 17:19:38 -0500 Message-Id: <20201118221939.20715-2-trondmy@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201118221939.20715-1-trondmy@kernel.org> References: <20201118221939.20715-1-trondmy@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust When doing a readlink, layoutget or getxattr call into an array of pages, we don't care if the XDR padding ends up in the last page when the data length is not 32-bit aligned. Avoid an unnecessary copy by just leaving that padding in place. Signed-off-by: Trond Myklebust --- fs/nfs/nfs2xdr.c | 2 +- fs/nfs/nfs3xdr.c | 2 +- fs/nfs/nfs42xdr.c | 2 +- fs/nfs/nfs4xdr.c | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c index f6676af37d5d..db9c265ad9e1 100644 --- a/fs/nfs/nfs2xdr.c +++ b/fs/nfs/nfs2xdr.c @@ -437,7 +437,7 @@ static int decode_path(struct xdr_stream *xdr) length = be32_to_cpup(p); if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN)) goto out_size; - recvd = xdr_read_pages(xdr, length); + recvd = xdr_read_pages(xdr, xdr_align_size(length)); if (unlikely(length > recvd)) goto out_cheating; xdr_terminate_string(xdr->buf, length); diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c index 69971f6c840d..d3e1726d538b 100644 --- a/fs/nfs/nfs3xdr.c +++ b/fs/nfs/nfs3xdr.c @@ -234,7 +234,7 @@ static int decode_nfspath3(struct xdr_stream *xdr) count = be32_to_cpup(p); if (unlikely(count >= xdr->buf->page_len || count > NFS3_MAXPATHLEN)) goto out_nametoolong; - recvd = xdr_read_pages(xdr, count); + recvd = xdr_read_pages(xdr, xdr_align_size(count)); if (unlikely(count > recvd)) goto out_cheating; xdr_terminate_string(xdr->buf, count); diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c index 6e060a88f98c..e58bfe208ae8 100644 --- a/fs/nfs/nfs42xdr.c +++ b/fs/nfs/nfs42xdr.c @@ -495,7 +495,7 @@ static int decode_getxattr(struct xdr_stream *xdr, res->xattr_len = len; if (len > 0) { - rdlen = xdr_read_pages(xdr, len); + rdlen = xdr_read_pages(xdr, xdr_align_size(len)); if (rdlen < len) return -EIO; } diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index c8714381d511..755b556e85c3 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -5250,7 +5250,7 @@ static int decode_readlink(struct xdr_stream *xdr, struct rpc_rqst *req) dprintk("nfs: server returned giant symlink!\n"); return -ENAMETOOLONG; } - recvd = xdr_read_pages(xdr, len); + recvd = xdr_read_pages(xdr, xdr_align_size(len)); if (recvd < len) { dprintk("NFS: server cheating in readlink reply: " "count %u > recvd %u\n", len, recvd); @@ -5925,7 +5925,7 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req, res->type, res->layoutp->len); - recvd = xdr_read_pages(xdr, res->layoutp->len); + recvd = xdr_read_pages(xdr, xdr_align_size(res->layoutp->len)); if (res->layoutp->len > recvd) { dprintk("NFS: server cheating in layoutget reply: " "layout len %u > recvd %u\n", -- 2.28.0