From patchwork Wed May 27 14:17:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 1298955 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=jBKa01d6; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49XCbV382Yz9sPF for ; Thu, 28 May 2020 00:17:58 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388138AbgE0OR5 (ORCPT ); Wed, 27 May 2020 10:17:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387755AbgE0OR5 (ORCPT ); Wed, 27 May 2020 10:17:57 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3758C08C5C2 for ; Wed, 27 May 2020 07:17:56 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id f5so3200903wmh.2 for ; Wed, 27 May 2020 07:17:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=YH1v8wKe1VUKWAjGTwnWnKdT9B4ah56ml0/ndiIz5io=; b=jBKa01d6epycwm2tJPgKP5MJmpfECW/858iC9R+HX+08ZSdRe1VOune12GU5FSK6jL 9ch+4WqcdFqtQm1Uw+0hpM8lDcfTvLDZZoF4N/Nxuz5BB5rrZjHqDr6pE2iuPToiG2h7 Z5zDJ2TE/ReBM6Aoi/RDfJTpsoxuPWS1pwkhI= 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:mime-version :content-transfer-encoding; bh=YH1v8wKe1VUKWAjGTwnWnKdT9B4ah56ml0/ndiIz5io=; b=Gt7dKry3z0xMkEkuReTrXwZgMjLIJgCkjrB97cFEyDnWXgmmZlAdqsWJUdN0id1BHg HHYMnNQQsfNP55PsbyWhPAau6iJ5lrIDvth8Ap89zzybomM+2n1gWoFiq7i6onsG7jLP GWPqp/J93n5ao7jYa8p1fRix8QJVqL3pGsdQeNHgsR/L9kQfcTyd0yQFz/IrC0G/1WFV 4dZVfuvhBGk50Qm3eHTRpMSXk65VdVd20s3C9sdeOGpCRdpdC5rjEfWV+tBRcCCKG7X4 +UoFzj/+q8eXIT6KlpP5owkpQrczNpK8zzAXq6/znN3PgzW5+KU3oYzU9GnaL6gJ8C6e V5+Q== X-Gm-Message-State: AOAM533qTdS7JhYfoH+JO4ZiNVO/mRpKWYqRoU6K1ZI7yGN6HUbZamVF PMWQsU+vyAIGZjJaJbnSVsSY9Q== X-Google-Smtp-Source: ABdhPJwWguHm0Lnqvgwm14E6sIExIuStJrZLuVvOVvX+cd+cFq+0BnVHHJ+F5pSSo7Tq7jwp6YH5nA== X-Received: by 2002:a05:600c:2256:: with SMTP id a22mr4092817wmm.18.1590589075512; Wed, 27 May 2020 07:17:55 -0700 (PDT) Received: from kpsingh.zrh.corp.google.com ([81.6.44.51]) by smtp.gmail.com with ESMTPSA id o15sm3026908wrv.48.2020.05.27.07.17.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 May 2020 07:17:55 -0700 (PDT) From: KP Singh To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org Cc: Brendan Jackman , Alexei Starovoitov , Daniel Borkmann , Alexander Viro , Christoph Hellwig Subject: [PATCH] fs: Add an explicit might_sleep() to iput Date: Wed, 27 May 2020 16:17:53 +0200 Message-Id: <20200527141753.101163-1-kpsingh@chromium.org> X-Mailer: git-send-email 2.27.0.rc0.183.gde8f92d652-goog MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: KP Singh It is currently mentioned in the comments to the function that iput might sleep when the inode is destroyed. Have it call might_sleep, as dput already does. Adding an explicity might_sleep() would help in quickly realizing that iput is called from a place where sleeping is not allowed when CONFIG_DEBUG_ATOMIC_SLEEP is enabled as noticed in the dicussion: https://lore.kernel.org/bpf/20200527021111.GA197666@google.com/ Signed-off-by: KP Singh Reviewed-by: Brendan Jackman --- fs/inode.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/inode.c b/fs/inode.c index cc6e701b7e5d..f55e72e76266 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1583,6 +1583,7 @@ static void iput_final(struct inode *inode) */ void iput(struct inode *inode) { + might_sleep(); if (!inode) return; BUG_ON(inode->i_state & I_CLEAR);