From patchwork Thu Mar 9 18:57:03 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 9613963 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EC70360417 for ; Thu, 9 Mar 2017 19:01:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E9CC42864F for ; Thu, 9 Mar 2017 19:01:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DE8C528655; Thu, 9 Mar 2017 19:01:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 829032864F for ; Thu, 9 Mar 2017 19:01:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933057AbdCIS5M (ORCPT ); Thu, 9 Mar 2017 13:57:12 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38432 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932451AbdCIS5L (ORCPT ); Thu, 9 Mar 2017 13:57:11 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2CF1C80F99; Thu, 9 Mar 2017 18:57:06 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-66.rdu2.redhat.com [10.10.120.66] (may be forged)) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v29Iv4xq015795; Thu, 9 Mar 2017 13:57:05 -0500 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 11/27] afs: inode: Replace rcu_assign_pointer() with RCU_INIT_POINTER() From: David Howells To: viro@ZenIV.linux.org.uk Cc: dhowells@redhat.com, Andreea-Cristina Bernat , linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 09 Mar 2017 18:57:03 +0000 Message-ID: <148908582325.16794.13028557204537948191.stgit@warthog.procyon.org.uk> In-Reply-To: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> References: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Thu, 09 Mar 2017 18:57:06 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Andreea-Cristina Bernat The use of "rcu_assign_pointer()" is NULLing out the pointer. According to RCU_INIT_POINTER()'s block comment: "1. This use of RCU_INIT_POINTER() is NULLing out the pointer" it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., NULL) Signed-off-by: Andreea-Cristina Bernat Signed-off-by: David Howells --- fs/afs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/afs/inode.c b/fs/afs/inode.c index ade6ec3873cf..e083e086b7ca 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -445,7 +445,7 @@ void afs_evict_inode(struct inode *inode) mutex_lock(&vnode->permits_lock); permits = vnode->permits; - rcu_assign_pointer(vnode->permits, NULL); + RCU_INIT_POINTER(vnode->permits, NULL); mutex_unlock(&vnode->permits_lock); if (permits) call_rcu(&permits->rcu, afs_zap_permits);