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,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 64434C63697 for ; Sun, 22 Nov 2020 20:52:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10ADE20789 for ; Sun, 22 Nov 2020 20:52:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="zBGda7Gz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727429AbgKVUwg (ORCPT ); Sun, 22 Nov 2020 15:52:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:57560 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727398AbgKVUwg (ORCPT ); Sun, 22 Nov 2020 15:52:36 -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 6BA6F20782 for ; Sun, 22 Nov 2020 20:52:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606078355; bh=vVr7Ctb2zm7C6qsRF0nmjqqjxOoMzfEA86nB2IOr9+4=; h=From:To:Subject:Date:In-Reply-To:References:From; b=zBGda7GzJoGxXtlT+eT8w2E0sUNY/XJYi/HrVnxdz311h+QeKNmWMTtBc6mDXDghZ A2guPw0LuHbckZilpgxCtdbJsaBsHbl3QhzTcggVTA5LrGaOT6UaIaqnmQDjH+W2dY xa6mBc9k1fItUjV7bBuuTEbhF1SCanbam5laZvv0= From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH 4/8] SUNRPC: Fix up xdr_read_pages() to take arbitrary object lengths Date: Sun, 22 Nov 2020 15:52:25 -0500 Message-Id: <20201122205229.3826-5-trondmy@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201122205229.3826-4-trondmy@kernel.org> References: <20201122205229.3826-1-trondmy@kernel.org> <20201122205229.3826-2-trondmy@kernel.org> <20201122205229.3826-3-trondmy@kernel.org> <20201122205229.3826-4-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 Fix up xdr_read_pages() so that it can handle object lengths that are larger than the page length, by simply aligning to the next object in the buffer tail. The function will continue to return the length of the truncate object data that actually fit into the pages. Signed-off-by: Trond Myklebust --- net/sunrpc/xdr.c | 41 +++++++++++++++-------------------------- 1 file changed, 15 insertions(+), 26 deletions(-) diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 394297ec1cb9..3ce0a5daa9eb 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1219,44 +1219,33 @@ static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len) } /** - * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position + * xdr_read_pages - align page-based XDR data to current pointer position * @xdr: pointer to xdr_stream struct * @len: number of bytes of page data * * Moves data beyond the current pointer position from the XDR head[] buffer - * into the page list. Any data that lies beyond current position + "len" - * bytes is moved into the XDR tail[]. + * into the page list. Any data that lies beyond current position + @len + * bytes is moved into the XDR tail[]. The xdr_stream current position is + * then advanced past that data to align to the next XDR object in the tail. * * Returns the number of XDR encoded bytes now contained in the pages */ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) { - struct xdr_buf *buf = xdr->buf; - struct kvec *iov; - unsigned int nwords; - unsigned int end; - unsigned int padding; + unsigned int nwords = XDR_QUADLEN(len); + unsigned int base, end, pglen; - len = xdr_align_pages(xdr, len); - if (len == 0) + pglen = xdr_align_pages(xdr, nwords << 2); + if (pglen == 0) return 0; - nwords = XDR_QUADLEN(len); - padding = (nwords << 2) - len; - xdr->iov = iov = buf->tail; - /* Compute remaining message length. */ - end = ((xdr->nwords - nwords) << 2) + padding; - if (end > iov->iov_len) - end = iov->iov_len; - /* - * Position current pointer at beginning of tail, and - * set remaining message length. - */ - xdr->p = (__be32 *)((char *)iov->iov_base + padding); - xdr->end = (__be32 *)((char *)iov->iov_base + end); - xdr->page_ptr = NULL; - xdr->nwords = XDR_QUADLEN(end - padding); - return len; + xdr->nwords -= nwords; + base = (nwords << 2) - pglen; + end = xdr_stream_remaining(xdr) - pglen; + + if (xdr_set_iov(xdr, xdr->buf->tail, base, end) == 0) + xdr->nwords = 0; + return len <= pglen ? len : pglen; } EXPORT_SYMBOL_GPL(xdr_read_pages); -- 2.28.0