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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 75C7EC4338F for ; Tue, 24 Aug 2021 13:25:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F136611AF for ; Tue, 24 Aug 2021 13:25:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237485AbhHXN0B (ORCPT ); Tue, 24 Aug 2021 09:26:01 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:37349 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237589AbhHXNZx (ORCPT ); Tue, 24 Aug 2021 09:25:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629811509; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=h2Qta3tolraxtrizV7nWCzmHIjkmwUURhMGBy2rmL/A=; b=YCCTUMpk/KJMRwj8pPvs91kkyQVZKgQhJ4FfMfcDyTO1l+lTnGfVnSdsMEd+xrY0TbPX2X 34rNo0+bYOlcLQcBrfbC50xOf20wznsx5ohx4S2xjKGjOwf1NljD/kimNUM3eWd3PkkVHn SOsZGnHMrduM9s8Fe2T+WQ58vNU2GdQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-538-Y926XhEaO66XEOrzBoN50Q-1; Tue, 24 Aug 2021 09:25:08 -0400 X-MC-Unique: Y926XhEaO66XEOrzBoN50Q-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 505201082921; Tue, 24 Aug 2021 13:25:06 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id 01E6D60C05; Tue, 24 Aug 2021 13:24:59 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 2/6] folio: Add a function to change the private data attached to a folio From: David Howells To: "Matthew Wilcox (Oracle)" Cc: dhowells@redhat.com, Jeff Layton , Ilya Dryomov , linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, devel@lists.orangefs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Tue, 24 Aug 2021 14:24:59 +0100 Message-ID: <162981149911.1901565.17776700811659843340.stgit@warthog.procyon.org.uk> In-Reply-To: <162981147473.1901565.1455657509200944265.stgit@warthog.procyon.org.uk> References: <162981147473.1901565.1455657509200944265.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Add a function, folio_change_private(), that will change the private data attached to a folio, without the need to twiddle the private bit or the refcount. It assumes that folio_add_private() has already been called on the page. Signed-off-by: David Howells Reviewed-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index f55d8d9001a9..c8d336e62177 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -229,6 +229,25 @@ static inline void folio_attach_private(struct folio *folio, void *data) folio_set_private(folio); } +/** + * folio_change_private - Change private data on a folio. + * @folio: Folio to change the data on. + * @data: Data to set on the folio. + * + * Change the private data attached to a folio and return the old + * data. The page must previously have had data attached and the data + * must be detached before the folio will be freed. + * + * Return: Data that was previously attached to the folio. + */ +static inline void *folio_change_private(struct folio *folio, void *data) +{ + void *old = folio_get_private(folio); + + folio->private = data; + return old; +} + /** * folio_detach_private - Detach private data from a folio. * @folio: Folio to detach data from.