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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 58164C43441 for ; Mon, 26 Nov 2018 16:44:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ABFCF20659 for ; Mon, 26 Nov 2018 16:44:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="ECCikKGV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ABFCF20659 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=amarulasolutions.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726548AbeK0DjF (ORCPT ); Mon, 26 Nov 2018 22:39:05 -0500 Received: from mail-ed1-f67.google.com ([209.85.208.67]:36710 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbeK0DjE (ORCPT ); Mon, 26 Nov 2018 22:39:04 -0500 Received: by mail-ed1-f67.google.com with SMTP id f23so16442434edb.3 for ; Mon, 26 Nov 2018 08:44:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=from:to:cc:subject:date:message-id; bh=8evddiikL3tOqy/f4zVT9/kxTqkXqGrvFI9LY5FHVe0=; b=ECCikKGVD+N3PsqCd5E+Pbym0YTKSHWI8O6+I32D0JDezLaJ4vCJszkqzU7KMyjbOk FCU5UY9njvUVPdZBctHXYvfBFJlnxFk0DHFTJpXqbLaCETmEwinxulC8Dd8d3VEBDRVW mNCdhZ3Y1m7D5ZcmU9zksZdX4zWSrrc+frIeM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=8evddiikL3tOqy/f4zVT9/kxTqkXqGrvFI9LY5FHVe0=; b=ePswq/mXaFEDzEvaKWovDqJgoX8VKDBy/bw5w1Q8EpK8gsDp3IRo6iTHR89gCWFGCF kWCJpT84KOd7T/AzUXpLDSVOF66c8aJKcMLuuYT+Q+fzwX1lLGiaZw19ifT1ui5gVJxe FfaAOhUBMxX9tyOBxfLLUQYHFX0Fb54MH5MDED5494BhhNqHXU61e60jpl32Mm3ZtPYx Lys68Ztax7VBJ3oANy082xjQ7+bkLQRMKAr3OHG1191twSDw7Yoi1lYheYV4CrTcaq+p Fmz64xnhyPrWjYeQapEF83ulFdd5m0+mxSDIKlOI7sAT3YlEbjwo9PBLhIXWXZHEV1Ul ME1A== X-Gm-Message-State: AGRZ1gK1H9CLaWs1JO7v+UI16MDuBGgJQ60LpfoHkGVDeCEMagKDhTJw hIWHKiZIbZtRHT5TQU16+tS6OA== X-Google-Smtp-Source: AJdET5fJBjc51Qt6jDVoNLTg/rnEcY8rm9YKRQSYQaQNkGey3+aVCITDtCCVUsD1jwhrI64YMguDiQ== X-Received: by 2002:a17:906:7a9c:: with SMTP id f28-v6mr20925980ejo.135.1543250665013; Mon, 26 Nov 2018 08:44:25 -0800 (PST) Received: from andrea.amarulasolutions.com (85.100.broadband17.iol.cz. [109.80.100.85]) by smtp.gmail.com with ESMTPSA id k32sm297995edb.42.2018.11.26.08.44.23 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Nov 2018 08:44:24 -0800 (PST) From: Andrea Parri To: David Howells Cc: linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, Andrea Parri Subject: [PATCH] afs: Add missing memory barriers in afs_manage_cell() Date: Mon, 26 Nov 2018 17:44:12 +0100 Message-Id: <20181126164412.11184-1-andrea.parri@amarulasolutions.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As the comments for wake_up_bit() and waitqueue_active() point out, the barriers are needed to order the clearing of the _FL_NOT_READY bit and the waitqueue_active() load; match the implicit barrier in prepare_to_wait(). Signed-off-by: Andrea Parri --- fs/afs/cell.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/afs/cell.c b/fs/afs/cell.c index cf445dbd5f2e0..a9488abe56029 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -637,6 +637,7 @@ static void afs_manage_cell(struct work_struct *work) cell->state = AFS_CELL_ACTIVE; smp_wmb(); clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags); + smp_mb__after_atomic(); /* see comment for wake_up_bit() */ wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY); goto again; @@ -678,6 +679,7 @@ static void afs_manage_cell(struct work_struct *work) cell->state = AFS_CELL_ACTIVE; smp_wmb(); clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags); + smp_mb__after_atomic(); /* see comment for wake_up_bit() */ wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY); _leave(" [deact->act]"); return; -- 2.17.1