From patchwork Thu Jul 21 18:21:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna Schumaker X-Patchwork-Id: 12925680 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 448EECCA487 for ; Thu, 21 Jul 2022 18:21:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229555AbiGUSVl (ORCPT ); Thu, 21 Jul 2022 14:21:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231672AbiGUSVk (ORCPT ); Thu, 21 Jul 2022 14:21:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A87582117 for ; Thu, 21 Jul 2022 11:21:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 35CD061FC8 for ; Thu, 21 Jul 2022 18:21:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41465C341C0; Thu, 21 Jul 2022 18:21:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1658427698; bh=mWaQeKFwusCVldo8R2eermzlT0tF5iUjW1pL24dk1x4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ssneteS0hzF5ILsy68kY1gFPiMrblrVDtzARlBXLouzb9CgrEIeWNOxDINbWfYtid /aYawLfmACbxdNGtmJL5PnWspFnO6u4vltenMsdwpVPh0lexDaq5nQvo2HOYfODbIo UrtO34VJ9GGbu7s1AzR3+hQkziBFVHlJEKMeaSl86sPCoLLy5JTYPkkjV/0M04ucev CKK+ia+0OWxnrsKsSoTbw0N8hs+pbLUJTcLd8U8LrIFkcrW8+TU1s5uwyL10tamk1o WCa3hJQPv5s+G7vOBrFMEHq0nJ0qSOusSOZj5Lmt9ZznEKEuBVKNLEYilIB3okCyCt e3U1e4nRw4Gwg== From: Anna Schumaker To: linux-nfs@vger.kernel.org, trond.myklebust@hammerspace.com Cc: anna@kernel.org Subject: [PATCH v3 2/5] SUNRPC: Add a function for directly setting the xdr page len Date: Thu, 21 Jul 2022 14:21:32 -0400 Message-Id: <20220721182135.1885071-3-anna@kernel.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220721182135.1885071-1-anna@kernel.org> References: <20220721182135.1885071-1-anna@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Anna Schumaker We need to do this step during READ_PLUS decoding so that we know pages are the right length and any extra data has been preserved in the tail. Signed-off-by: Anna Schumaker --- include/linux/sunrpc/xdr.h | 1 + net/sunrpc/xdr.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 7dcc6c31fe29..8cd38a9994ca 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -258,6 +258,7 @@ extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes); extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); +extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len); extern unsigned int xdr_align_data(struct xdr_stream *, unsigned int offset, unsigned int length); extern unsigned int xdr_expand_hole(struct xdr_stream *, unsigned int offset, unsigned int length); extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf, diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 8ba11a754297..e4ac700ca554 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1500,6 +1500,36 @@ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) } EXPORT_SYMBOL_GPL(xdr_read_pages); +/** + * xdr_set_pagelen - Sets the length of the XDR pages + * @xdr: pointer to xdr_stream struct + * @len: new length of the XDR page data + * + * Either grows or shrinks the length of the xdr pages by setting pagelen to + * @len bytes. When shrinking, any extra data is moved into buf->tail, whereas + * when growing any data beyond the current pointer is moved into the tail. + * + * Returns True if the operation was successful, and False otherwise. + */ +void xdr_set_pagelen(struct xdr_stream *xdr, unsigned int len) +{ + struct xdr_buf *buf = xdr->buf; + size_t remaining = xdr_stream_remaining(xdr); + size_t base = 0; + + if (len < buf->page_len) { + base = buf->page_len - len; + xdr_shrink_pagelen(buf, len); + } else { + xdr_buf_head_shift_right(buf, xdr_stream_pos(xdr), + buf->page_len, remaining); + if (len > buf->page_len) + xdr_buf_try_expand(buf, len - buf->page_len); + } + xdr_set_tail_base(xdr, base, remaining); +} +EXPORT_SYMBOL_GPL(xdr_set_pagelen); + unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset, unsigned int length) {