From patchwork Wed Apr 1 16:18:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 228427 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 E0F64C2BA12 for ; Wed, 1 Apr 2020 16:39:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5E3A20857 for ; Wed, 1 Apr 2020 16:39:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759173; bh=zI1L8fWuxnVasn0HN2osMoOEJhb/uWGdUVBR50usJHc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xK0GGPSskDZ90i4R4w/L5Gu7VAEF3OboekfGGr5MW4kD28RdDQfabKme0FtW/Q3qc /J8SA6zFubqpsDqBNaslsZbepskTKzaxtBdW8gAoGSd7Z64r3sBOugDzRrzvRtjW7u T2HitcGWsmeHAV/i67JPTEb6BSvaheCSQJPr9V6s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388613AbgDAQjZ (ORCPT ); Wed, 1 Apr 2020 12:39:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:39310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389171AbgDAQjY (ORCPT ); Wed, 1 Apr 2020 12:39:24 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 13E5B20719; Wed, 1 Apr 2020 16:39:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759162; bh=zI1L8fWuxnVasn0HN2osMoOEJhb/uWGdUVBR50usJHc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MzpPFqYKXbJv/q6I2NMgp3/XTJKGlerhLJxcdV0qQXQfgPQD0w1WgHHAOg5BTw62e mgWYAlMY0u0Xlhute+Cbu6Wdm8qclqiWx4HjgvOxZKaj9UUg71nZTnQni79D2g49wQ dHdArfCjOFqiF7KdyyS2fU+k5KlAxP4Efy6DN44Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Peter Zijlstra (Intel)" , Andrew Morton , Linus Torvalds , "Paul E. McKenney" , Thomas Gleixner , Ingo Molnar Subject: [PATCH 4.9 097/102] locking/atomic, kref: Add kref_read() Date: Wed, 1 Apr 2020 18:18:40 +0200 Message-Id: <20200401161548.288744634@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200401161530.451355388@linuxfoundation.org> References: <20200401161530.451355388@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Peter Zijlstra commit 2c935bc57221cc2edc787c72ea0e2d30cdcd3d5e upstream. Since we need to change the implementation, stop exposing internals. Provide kref_read() to read the current reference count; typically used for debug messages. Kills two anti-patterns: atomic_read(&kref->refcount) kref->refcount.counter Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar [only add kref_read() to kref.h for stable backports - gregkh] Signed-off-by: Greg Kroah-Hartman --- include/linux/kref.h | 5 +++++ 1 file changed, 5 insertions(+) --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -33,6 +33,11 @@ static inline void kref_init(struct kref atomic_set(&kref->refcount, 1); } +static inline int kref_read(const struct kref *kref) +{ + return atomic_read(&kref->refcount); +} + /** * kref_get - increment refcount for object. * @kref: object.