From patchwork Tue Sep 8 16:25:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna Schumaker X-Patchwork-Id: 11763647 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B77AD618 for ; Tue, 8 Sep 2020 16:48:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 951D420759 for ; Tue, 8 Sep 2020 16:48:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="VhEc2vA5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731955AbgIHQrJ (ORCPT ); Tue, 8 Sep 2020 12:47:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731951AbgIHQ0T (ORCPT ); Tue, 8 Sep 2020 12:26:19 -0400 Received: from mail-il1-x141.google.com (mail-il1-x141.google.com [IPv6:2607:f8b0:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92AE5C061798 for ; Tue, 8 Sep 2020 09:25:24 -0700 (PDT) Received: by mail-il1-x141.google.com with SMTP id w8so15978124ilj.8 for ; Tue, 08 Sep 2020 09:25:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=2rFFPC6YSbh+Yg76JGYrEMjlWJn6VCP0QhRCqwz1dRg=; b=VhEc2vA5JOlYONpG/ZHqQHhV26zKREdw17EUFXH1PEkRI7luvmNHA+a80U94nPG9Kj jUfF3wKW76/5ttCxaJyADBKiWRiV7DyrMcAM/DnfU5WsVp+cgj5RB6gJVwoSvYmYYDG7 YAf5wFKHmvBpQ/RriFncvunSJEu4O9SeYxEi4x4/KaDZj96gew3/6iukMOZ1YOP9wjEO dm7fOt9uJKwAlcfAIsjOovkHG9u7QF+Z+zIxcOHa3vI673pvU9fT1sNBBtHoyFQ8tOOf jpACBnfz9lHmeQsJH0t92Omvt9xw081neh3kEeikjEkKM0N+y6fcbU4g5YpFSaG6mfk2 Nn7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=2rFFPC6YSbh+Yg76JGYrEMjlWJn6VCP0QhRCqwz1dRg=; b=IQeQ0/PqOG/3iqeCkwfw773KdaxZaVbZ+R0mLWtGjzkZnEyR85m3Zr/3JKPiFQHCUF CHY977QHPFWmlDXv9cT/HyVkCZO4GdLRvUNYCP3aAxlKkCTNqbiq8MD11XTMAcRHy8Qa xOX4ChPfyNpK2qJqPv2INND3lY7mE+FkuYH1sLXWDrEjSc4pj4Uzmyy4Z++9cN4XQyne H3k4qC1PUVbwH7B2kSMB17YsgjJF1/DhhXy9LLMPmhaSnrTVSoo2tlIYlDE+N42syCXE FUtKuKR5A1pWfkhOtiRMegZEXqMHa3D6KyUHK0MIIu0tOWvEagUjkoqPRrLQkz5LgyjD zBsg== X-Gm-Message-State: AOAM531G1MM2bjv8qn+1t+VMvJw4M1L14dubnvmSR6iQTPuhgX5lxeRX 3W0v87cJ5gVf98kkLxP5yqOFIqYnmtA= X-Google-Smtp-Source: ABdhPJyc/y089o0+LVFu2CFb/UuRjezqyx1O9opRGNQ3EU8vR6VGG9NGFwqg+g+j6SyZJ7XHWfXFxg== X-Received: by 2002:a92:1a48:: with SMTP id z8mr17417327ill.95.1599582323611; Tue, 08 Sep 2020 09:25:23 -0700 (PDT) Received: from gouda.nowheycreamery.com (c-68-32-74-190.hsd1.mi.comcast.net. [68.32.74.190]) by smtp.gmail.com with ESMTPSA id 2sm10291375ilj.24.2020.09.08.09.25.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Sep 2020 09:25:23 -0700 (PDT) From: schumaker.anna@gmail.com X-Google-Original-From: Anna.Schumaker@Netapp.com To: linux-nfs@vger.kernel.org Cc: Anna.Schumaker@Netapp.com Subject: [PATCH v5 09/10] SUNRPC: Add an xdr_align_data() function Date: Tue, 8 Sep 2020 12:25:12 -0400 Message-Id: <20200908162513.508991-10-Anna.Schumaker@Netapp.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908162513.508991-1-Anna.Schumaker@Netapp.com> References: <20200908162513.508991-1-Anna.Schumaker@Netapp.com> MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Anna Schumaker For now, this function simply aligns the data at the beginning of the pages. This can eventually be expanded to shift data to the correct offsets when we're ready. Signed-off-by: Anna Schumaker --- include/linux/sunrpc/xdr.h | 1 + net/sunrpc/xdr.c | 121 +++++++++++++++++++++++++++++++++++++ 2 files changed, 122 insertions(+) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 36a81c29542e..9548d075e06d 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -252,6 +252,7 @@ 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(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); +extern uint64_t xdr_align_data(struct xdr_stream *, uint64_t, uint32_t); extern uint64_t xdr_expand_hole(struct xdr_stream *, uint64_t, uint64_t); /** diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 24baf052e6e6..e799cbfe6b5a 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -19,6 +19,9 @@ #include #include +static void _copy_to_pages(struct page **, size_t, const char *, size_t); + + /* * XDR functions for basic NFS types */ @@ -201,6 +204,88 @@ EXPORT_SYMBOL_GPL(xdr_inline_pages); * Helper routines for doing 'memmove' like operations on a struct xdr_buf */ +/** + * _shift_data_left_pages + * @pages: vector of pages containing both the source and dest memory area. + * @pgto_base: page vector address of destination + * @pgfrom_base: page vector address of source + * @len: number of bytes to copy + * + * Note: the addresses pgto_base and pgfrom_base are both calculated in + * the same way: + * if a memory area starts at byte 'base' in page 'pages[i]', + * then its address is given as (i << PAGE_CACHE_SHIFT) + base + * Alse note: pgto_base must be < pgfrom_base, but the memory areas + * they point to may overlap. + */ +static void +_shift_data_left_pages(struct page **pages, size_t pgto_base, + size_t pgfrom_base, size_t len) +{ + struct page **pgfrom, **pgto; + char *vfrom, *vto; + size_t copy; + + BUG_ON(pgfrom_base <= pgto_base); + + pgto = pages + (pgto_base >> PAGE_SHIFT); + pgfrom = pages + (pgfrom_base >> PAGE_SHIFT); + + pgto_base &= ~PAGE_MASK; + pgfrom_base &= ~PAGE_MASK; + + do { + if (pgto_base >= PAGE_SIZE) { + pgto_base = 0; + pgto++; + } + if (pgfrom_base >= PAGE_SIZE){ + pgfrom_base = 0; + pgfrom++; + } + + copy = len; + if (copy > (PAGE_SIZE - pgto_base)) + copy = PAGE_SIZE - pgto_base; + if (copy > (PAGE_SIZE - pgfrom_base)) + copy = PAGE_SIZE - pgfrom_base; + + vto = kmap_atomic(*pgto); + if (*pgto != *pgfrom) { + vfrom = kmap_atomic(*pgfrom); + memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); + kunmap_atomic(vfrom); + } else + memmove(vto + pgto_base, vto + pgfrom_base, copy); + flush_dcache_page(*pgto); + kunmap_atomic(vto); + + pgto_base += copy; + pgfrom_base += copy; + + } while ((len -= copy) != 0); +} + +static void +_shift_data_left_tail(struct xdr_buf *buf, unsigned int pgto, size_t len) +{ + struct kvec *tail = buf->tail; + + if (len > tail->iov_len) + len = tail->iov_len; + + _copy_to_pages(buf->pages, + buf->page_base + pgto, + (char *)tail->iov_base, + len); + tail->iov_len -= len; + + if (tail->iov_len > 0) + memmove((char *)tail->iov_base, + tail->iov_base + len, + tail->iov_len); +} + /** * _shift_data_right_pages * @pages: vector of pages containing both the source and dest memory area. @@ -1177,6 +1262,42 @@ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) } EXPORT_SYMBOL_GPL(xdr_read_pages); +uint64_t xdr_align_data(struct xdr_stream *xdr, uint64_t offset, uint32_t length) +{ + struct xdr_buf *buf = xdr->buf; + unsigned int from, bytes; + unsigned int shift = 0; + + if ((offset + length) < offset || + (offset + length) > buf->page_len) + length = buf->page_len - offset; + + xdr_realign_pages(xdr); + from = xdr_page_pos(xdr); + bytes = xdr->nwords << 2; + if (length < bytes) + bytes = length; + + /* Move page data to the left */ + if (from > offset) { + shift = min_t(unsigned int, bytes, buf->page_len - from); + _shift_data_left_pages(buf->pages, + buf->page_base + offset, + buf->page_base + from, + shift); + bytes -= shift; + + /* Move tail data into the pages, if necessary */ + if (bytes > 0) + _shift_data_left_tail(buf, offset + shift, bytes); + } + + xdr->nwords -= XDR_QUADLEN(length); + xdr_set_page(xdr, from + length, PAGE_SIZE); + return length; +} +EXPORT_SYMBOL_GPL(xdr_align_data); + uint64_t xdr_expand_hole(struct xdr_stream *xdr, uint64_t offset, uint64_t length) { struct xdr_buf *buf = xdr->buf;