From patchwork Tue Oct 6 16:29:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna Schumaker X-Patchwork-Id: 11818979 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 A167E15E6 for ; Tue, 6 Oct 2020 16:29:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 85166206F7 for ; Tue, 6 Oct 2020 16:29:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="EFZhIHKz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726128AbgJFQ3g (ORCPT ); Tue, 6 Oct 2020 12:29:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725902AbgJFQ3g (ORCPT ); Tue, 6 Oct 2020 12:29:36 -0400 Received: from mail-qt1-x841.google.com (mail-qt1-x841.google.com [IPv6:2607:f8b0:4864:20::841]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26FB0C061755 for ; Tue, 6 Oct 2020 09:29:36 -0700 (PDT) Received: by mail-qt1-x841.google.com with SMTP id c23so6394798qtp.0 for ; Tue, 06 Oct 2020 09:29:36 -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=xSNY5rs/LPqHq45LaVf0JSFPkxQWNjnF02QzT07AF1c=; b=EFZhIHKzaKP1x8QtaQUh295bpzcfv4jQiQXRbvRUjotcPpaeCmM7ilBwnDTq3zhKnv iEC9jjE+dMvcDss9iiZ3Bwj9eLvM92WHR01j2PSPechMhzfIFbXF3PaJ3O3UhZ9OH1YQ DJqv1RdK6+HRT7aBdDWVsdbfk5RE1HIujpaTuShJnB7PH8MqZyNBpaNRtxTJzV0QhEVI H0kWs6r5d1PqDgmQrvZIXWBey7APFbrYCObYL6KhhdRQI8N1Nl+9566uXfr0r+wWgc8o E6Ylj95OLQCIf+hC34vlLHTtQFAJoZ1jmUMSlwWCr47SwRw9Ku51aaxSvpI22Bfrh7El Pieg== 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=xSNY5rs/LPqHq45LaVf0JSFPkxQWNjnF02QzT07AF1c=; b=hJ96EahEy5ywCufoa5OiNa13xB7yczmQC3GMUjaBdAgZAOnbh2eJ04aohQnrqGXEfS RLeugqnQXtrW5d457lkEVeXjT3kKPvWrBzCOTJ+9W7QoTImK7g+GitbWCoInu80KjjiN KxMgqcvufue+wrhgiPMY9rqvbxH3JVuESCeGWP8LccDhFZ9dX9I8xustOputciH9nZ/K prUSfnSqWddIcz3nbnReX2wcHkb7u6z18NgPWume3IXQMhSIUiNGmjuMWGP5ilPYu7cW 9aIyf47woMCyRBHSd2wvzWG1TDJcn6XqQLSY7DrOiSZBPI8YNhrGsom++hXBEOsrEyHQ F/+A== X-Gm-Message-State: AOAM530EzI6VJj8dHHUaLOHPtFMQWlRYwgDIYuxMdzytQo6BA68Mel+E nOUhAhOqFeFRtSfSBSbAf6W++KutnmNnoQ== X-Google-Smtp-Source: ABdhPJwrBBM6fZUeoCRrHgwbV25YjBwgTwcLZ0mbkGCNLqDe+o/6AMkOLWqPTT13Y+F+kJboKygB8g== X-Received: by 2002:ac8:1935:: with SMTP id t50mr5909546qtj.74.1602001774734; Tue, 06 Oct 2020 09:29:34 -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 q5sm2629984qtn.60.2020.10.06.09.29.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Oct 2020 09:29:34 -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 v7 07/10] SUNRPC: Add the ability to expand holes in data pages Date: Tue, 6 Oct 2020 12:29:22 -0400 Message-Id: <20201006162925.1331781-8-Anna.Schumaker@Netapp.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201006162925.1331781-1-Anna.Schumaker@Netapp.com> References: <20201006162925.1331781-1-Anna.Schumaker@Netapp.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Anna Schumaker This patch adds the ability to "read a hole" into a set of XDR data pages by taking the following steps: 1) Shift all data after the current xdr->p to the right, possibly into the tail, 2) Zero the specified range, and 3) Update xdr->p to point beyond the hole. Signed-off-by: Anna Schumaker --- - v7: Clean up _zero_pages() to remove an unnecessary conditional --- include/linux/sunrpc/xdr.h | 1 + net/sunrpc/xdr.c | 69 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 026edbd041d5..36a81c29542e 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_expand_hole(struct xdr_stream *, uint64_t, uint64_t); /** * xdr_stream_remaining - Return the number of bytes remaining in the stream diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index d8c9555c6f2b..3a168bd54c87 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -390,6 +390,38 @@ _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) } EXPORT_SYMBOL_GPL(_copy_from_pages); +/** + * _zero_pages + * @pages: array of pages + * @pgbase: beginning page vector address + * @len: length + */ +static void +_zero_pages(struct page **pages, size_t pgbase, size_t len) +{ + struct page **page; + char *vpage; + size_t zero; + + page = pages + (pgbase >> PAGE_SHIFT); + pgbase &= ~PAGE_MASK; + + do { + zero = PAGE_SIZE - pgbase; + if (zero > len) + zero = len; + + vpage = kmap_atomic(*page); + memset(vpage + pgbase, 0, zero); + kunmap_atomic(vpage); + + flush_dcache_page(*page); + pgbase = 0; + page++; + + } while ((len -= zero) != 0); +} + /** * xdr_shrink_bufhead * @buf: xdr_buf @@ -1141,6 +1173,43 @@ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) } EXPORT_SYMBOL_GPL(xdr_read_pages); +uint64_t xdr_expand_hole(struct xdr_stream *xdr, uint64_t offset, uint64_t length) +{ + struct xdr_buf *buf = xdr->buf; + unsigned int bytes; + unsigned int from; + unsigned int truncated = 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 (offset + length + bytes > buf->page_len) { + unsigned int shift = (offset + length + bytes) - buf->page_len; + unsigned int res = _shift_data_right_tail(buf, from + bytes - shift, shift); + truncated = shift - res; + xdr->nwords -= XDR_QUADLEN(truncated); + bytes -= shift; + } + + /* Now move the page data over and zero pages */ + if (bytes > 0) + _shift_data_right_pages(buf->pages, + buf->page_base + offset + length, + buf->page_base + from, + bytes); + _zero_pages(buf->pages, buf->page_base + offset, length); + + buf->len += length - (from - offset) - truncated; + xdr_set_page(xdr, offset + length, PAGE_SIZE); + return length; +} +EXPORT_SYMBOL_GPL(xdr_expand_hole); + /** * xdr_enter_page - decode data from the XDR page * @xdr: pointer to xdr_stream struct