From patchwork Tue Nov 26 04:34:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: kc27041980@gmail.com X-Patchwork-Id: 11261387 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 146F71390 for ; Tue, 26 Nov 2019 04:34:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA6B32084B for ; Tue, 26 Nov 2019 04:34:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="H0Ifhf9+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728460AbfKZEew (ORCPT ); Mon, 25 Nov 2019 23:34:52 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:44428 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727416AbfKZEew (ORCPT ); Mon, 25 Nov 2019 23:34:52 -0500 Received: by mail-pg1-f196.google.com with SMTP id e6so8296715pgi.11; Mon, 25 Nov 2019 20:34:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=r4sCXiFU1twmyenJG0NM7zHY2TV0D2ORPlGj2mpnJMI=; b=H0Ifhf9+PF78erKiS5IqjyZop5Wkcm2Y5P85j2gnzYg2sdG13OQBPzn8X1owYpfo0b FlpuQK+TdOjPwcXKFKavEhvcPogyDvJdCUqjwcdXzmUwfC689m3bhapXnMIMHyjAoskM zwq00UsoAoeWZ2pAQ/MXarvEllXZtnUY8O4FZY5NdcCxDKSsoatj4qEOc/4mZdU7iTHT tAJ+HyIW180xnFmpZXVHqDJvCD+CB+ontLHpEDMAwSgf1sg0TPz7n3df5FxsvX/ar3kA 20QuYpJzl89ONDQhxIiqx2yYe77o72A0kj1tWlEr6QrpGg77TZUVZ78ABt316NQnNgXH PDvg== 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=r4sCXiFU1twmyenJG0NM7zHY2TV0D2ORPlGj2mpnJMI=; b=NS5FTDSg0P0M7r5UFT8D3u0MH06VJGtbDV7ul+iG4RdoFyblwX+CwdsruVlZ4501r1 k7PjxAOZ8KrGP3NPVsCLoSPPTwv3LDEGFkd1sq/5A3oFCbyXSTMR5uUtU5aNDdVSnB2r dwzHtQthrZoeqP2pJ746N7QKz/DJLuDENjJ5IjOPLkDw/9TPfnWM3s7FY3xwfvqzFF9K cIN2ZwyAz+KfsQrXXaZLp8YMle+Cm7lhuBQ4zQtwr358auht1N02wem3ZL4LqthevLg7 7kMjUrN0nlwYYkRPC4xyguW9B1lUVkkZOpxUdR9132Cd/Wef8j1fpEfDk2H/AzAWS7QB uHkw== X-Gm-Message-State: APjAAAVdCFBo1MsE/40euPphH40mm3KpnhkU3A452JI1gvia/r/ne+g7 bJFFTGw+rhRz8V+SZhYJgew= X-Google-Smtp-Source: APXvYqy91r4SioV3aM4LfXCeaDZWLxEZmmP8CYnC/r2l1EkFlBW0Lo7+OWaTYCIGw0UmWuD7Rvwr9Q== X-Received: by 2002:a63:5f48:: with SMTP id t69mr35260836pgb.379.1574742891103; Mon, 25 Nov 2019 20:34:51 -0800 (PST) Received: from localhost.localdomain ([182.78.163.34]) by smtp.gmail.com with ESMTPSA id x9sm10279264pgt.66.2019.11.25.20.34.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 25 Nov 2019 20:34:50 -0800 (PST) From: kc27041980@gmail.com X-Google-Original-From: KC17041980@gmail.com To: Philipp Reisner , Lars Ellenberg , Jens Axboe Cc: drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, KC27041980 Subject: [PATCH 1/1] block/drbd/drbd_debugfs.c: Protect &connection->kref with resource->req_lock Date: Tue, 26 Nov 2019 10:04:18 +0530 Message-Id: <1574742858-23131-1-git-send-email-KC17041980@gmail.com> X-Mailer: git-send-email 2.7.4 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: KC27041980 Protect &connection->kref by moving it under resource->req_lock. Signed-off-by: KC27041980 --- drivers/block/drbd/drbd_debugfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_debugfs.c b/drivers/block/drbd/drbd_debugfs.c index b3b9cd5..f6d75fa 100644 --- a/drivers/block/drbd/drbd_debugfs.c +++ b/drivers/block/drbd/drbd_debugfs.c @@ -363,11 +363,15 @@ static int in_flight_summary_show(struct seq_file *m, void *pos) struct drbd_connection *connection; unsigned long jif = jiffies; + spin_lock_irq(&resource->req_lock); connection = first_connection(resource); /* This does not happen, actually. * But be robust and prepare for future code changes. */ - if (!connection || !kref_get_unless_zero(&connection->kref)) + if (!connection || !kref_get_unless_zero(&connection->kref)) { + spin_unlock_irq(&resource->req_lock); return -ESTALE; + } + spin_unlock_irq(&resource->req_lock); /* BUMP me if you change the file format/content/presentation */ seq_printf(m, "v: %u\n\n", 0);