From patchwork Mon Sep 28 17:09:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna Schumaker X-Patchwork-Id: 11804305 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 E0D3A618 for ; Mon, 28 Sep 2020 17:09:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB6FC20757 for ; Mon, 28 Sep 2020 17:09:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="B20FmcNw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726615AbgI1RJc (ORCPT ); Mon, 28 Sep 2020 13:09:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726513AbgI1RJb (ORCPT ); Mon, 28 Sep 2020 13:09:31 -0400 Received: from mail-qt1-x842.google.com (mail-qt1-x842.google.com [IPv6:2607:f8b0:4864:20::842]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A862DC061755 for ; Mon, 28 Sep 2020 10:09:31 -0700 (PDT) Received: by mail-qt1-x842.google.com with SMTP id c18so1331182qtw.5 for ; Mon, 28 Sep 2020 10:09:31 -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=B20FmcNwekmUnVJ5FTv7xvaUzDr+yOI5ILfuFpLG3hf6TUS+qGbAukejIqk1pOdrC5 fbmIIPTGeXJjUOzZ20fOgQZbB9v+ekZ/Zb2ZXLnm8dd0ammJsZ00C/wVmvKHsMntSnmM QdK0+diPznke7dwQdeGpEmvcxLMkp+fqQYGGAnizk6cqHn/X7Lh476qThATvTzg8/t5e bpivH5y7MiV6S5OAHemMbev2MzWnWQZSvMB9YXRR6CO1oK+geKmvqQjF4D0zQhkU2J/b Kn3AH3HQbbi9AQtCRRU7qhwM2gOG2M2LOKFK1Viqk1+UN7wuZfSx4sUSxwKVMp+owNyZ Akow== 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=JmChj/D1AetRek+l8+odlKnc6ucYuWcKd8+Sgk8ASADsChXPgNQvsqKToDNh/8YyU1 niEAirmBVXLdSETwKCGAVBiAeFJCi19NDahfnoZbixcyF8fvmSrPMkreEJMhydKhc7w+ C6lRn5wgSf31nMFEn4PrmHSaOUXBVqiBn8+qvWL245Wm26WpYBpfJHycP5E/xFrf4nGz HDbDoCxubac9NAAaR4yhDaqqX9R+0v8ys4cRjnynsaYs9/er2wroL7FiFQhfZQS/SJE/ 1+yENTq6ja0Qeof9RuLrfSPV9CJyTbZJvaVj9jkvt8xuoiZxC7jZn+oMFrVLQJ7sbxWh eMFA== X-Gm-Message-State: AOAM5338gaHQ2mXaDj1TRWXiu2/Rh3voHi2g5zEWjor4PtVkJCYX2TGk oUZrLn6lLhgvquCtBsUmACUVWcz/Xyo= X-Google-Smtp-Source: ABdhPJxPToJMwpGXwgZdM+tip84FBBv+Wi43Jx759wyuv4UFBd4Wq7OuaD1rhxTyeDgrJMSsOS2zMw== X-Received: by 2002:ac8:22f6:: with SMTP id g51mr2586635qta.282.1601312970570; Mon, 28 Sep 2020 10:09:30 -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 201sm1556862qkf.103.2020.09.28.10.09.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Sep 2020 10:09:30 -0700 (PDT) Sender: Anna Schumaker 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 v6 09/10] SUNRPC: Add an xdr_align_data() function Date: Mon, 28 Sep 2020 13:09:18 -0400 Message-Id: <20200928170919.707641-10-Anna.Schumaker@Netapp.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200928170919.707641-1-Anna.Schumaker@Netapp.com> References: <20200928170919.707641-1-Anna.Schumaker@Netapp.com> MIME-Version: 1.0 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;