From patchwork Wed Dec 23 21:06:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julia Lawall X-Patchwork-Id: 7914371 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B880E9F1AF for ; Wed, 23 Dec 2015 21:22:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D6FF5205C1 for ; Wed, 23 Dec 2015 21:22:10 +0000 (UTC) Received: from lists.xen.org (lists.xenproject.org [50.57.142.19]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E27EC20592 for ; Wed, 23 Dec 2015 21:22:09 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aBqoH-0006ti-Eh; Wed, 23 Dec 2015 21:19:01 +0000 Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aBqoF-0006td-Vy for xen-devel@lists.xenproject.org; Wed, 23 Dec 2015 21:19:00 +0000 Received: from [85.158.137.68] by server-10.bemta-3.messagelabs.com id 1C/34-02807-2CF0B765; Wed, 23 Dec 2015 21:18:58 +0000 X-Env-Sender: Julia.Lawall@lip6.fr X-Msg-Ref: server-12.tower-31.messagelabs.com!1450905536!12428495!1 X-Originating-IP: [192.134.164.83] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 7.35.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 51903 invoked from network); 23 Dec 2015 21:18:56 -0000 Received: from mail2-relais-roc.national.inria.fr (HELO mail2-relais-roc.national.inria.fr) (192.134.164.83) by server-12.tower-31.messagelabs.com with RC4-SHA encrypted SMTP; 23 Dec 2015 21:18:56 -0000 X-IronPort-AV: E=Sophos;i="5.20,470,1444687200"; d="scan'208";a="193852958" Received: from palace.rsr.lip6.fr (HELO localhost.localdomain) ([132.227.105.202]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/AES128-SHA256; 23 Dec 2015 22:18:55 +0100 From: Julia Lawall To: linux-mm@kvack.org Date: Wed, 23 Dec 2015 22:06:24 +0100 Message-Id: <1450904784-17139-1-git-send-email-Julia.Lawall@lip6.fr> X-Mailer: git-send-email 1.9.1 Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, David Vrabel , xen-devel@lists.xenproject.org, Boris Ostrovsky Subject: [Xen-devel] [PATCH] cleancache: constify cleancache_ops structure X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The cleancache_ops structure is never modified, so declare it as const. This also removes the __read_mostly declaration on the cleancache_ops variable declaration, since it seems redundant with const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall --- Not sure that the __read_mostly change is correct. Does it apply to the variable, or to what the variable points to? drivers/xen/tmem.c | 2 +- include/linux/cleancache.h | 2 +- mm/cleancache.c | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/cleancache.h b/include/linux/cleancache.h index bda5ec0b4..cb3e142 100644 --- a/include/linux/cleancache.h +++ b/include/linux/cleancache.h @@ -37,7 +37,7 @@ struct cleancache_ops { void (*invalidate_fs)(int); }; -extern int cleancache_register_ops(struct cleancache_ops *ops); +extern int cleancache_register_ops(const struct cleancache_ops *ops); extern void __cleancache_init_fs(struct super_block *); extern void __cleancache_init_shared_fs(struct super_block *); extern int __cleancache_get_page(struct page *); diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c index 945fc43..4ac2ca8 100644 --- a/drivers/xen/tmem.c +++ b/drivers/xen/tmem.c @@ -242,7 +242,7 @@ static int tmem_cleancache_init_shared_fs(char *uuid, size_t pagesize) return xen_tmem_new_pool(shared_uuid, TMEM_POOL_SHARED, pagesize); } -static struct cleancache_ops tmem_cleancache_ops = { +static const struct cleancache_ops tmem_cleancache_ops = { .put_page = tmem_cleancache_put_page, .get_page = tmem_cleancache_get_page, .invalidate_page = tmem_cleancache_flush_page, diff --git a/mm/cleancache.c b/mm/cleancache.c index 8fc5081..c6356d6 100644 --- a/mm/cleancache.c +++ b/mm/cleancache.c @@ -22,7 +22,7 @@ * cleancache_ops is set by cleancache_register_ops to contain the pointers * to the cleancache "backend" implementation functions. */ -static struct cleancache_ops *cleancache_ops __read_mostly; +static const struct cleancache_ops *cleancache_ops; /* * Counters available via /sys/kernel/debug/cleancache (if debugfs is @@ -49,7 +49,7 @@ static void cleancache_register_ops_sb(struct super_block *sb, void *unused) /* * Register operations for cleancache. Returns 0 on success. */ -int cleancache_register_ops(struct cleancache_ops *ops) +int cleancache_register_ops(const struct cleancache_ops *ops) { if (cmpxchg(&cleancache_ops, NULL, ops)) return -EBUSY;