From patchwork Wed Mar 4 17:06:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Domenico Andreoli X-Patchwork-Id: 11420509 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 CF39D1820 for ; Wed, 4 Mar 2020 17:06:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B096424654 for ; Wed, 4 Mar 2020 17:06:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UzWuKWhw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729613AbgCDRGz (ORCPT ); Wed, 4 Mar 2020 12:06:55 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:52685 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727709AbgCDRGy (ORCPT ); Wed, 4 Mar 2020 12:06:54 -0500 Received: by mail-wm1-f68.google.com with SMTP id p9so2981079wmc.2; Wed, 04 Mar 2020 09:06:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=eAvOIF6AGY3vlZ1kzI6VwMQbeJQz/suMmkKBmXk6J8Y=; b=UzWuKWhwSTJKSKcktovi82mOWChrc/f0KtLo4X5rUYd9T9r93VZEsjULHytd8lrxv5 YIjTecmQzPuwr7GMOVXPUDzk7lTvc126GlJ12boC1Sz8lUEzTYLgcL4e4+ZzBgZnaXgV yJnsaPX9X5VH511KEtLXIvytDFOzksJdNlA9OVlQIJHT1qYZpqldWsMilzD7CoLwojYe dUPg13pM6AO6vwLFYzO4RMgsvkXMOQwQ7VjuWB5iu3uobCoFQICIbneHO+1KAYyyzoAT rs+eqJyYPk72BAxEhnWCrgwDElzuYrpfn0wpJMW+tKXYEHArAEXOCq/oElUgKrHDfO1x 49+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :mime-version:content-disposition:user-agent; bh=eAvOIF6AGY3vlZ1kzI6VwMQbeJQz/suMmkKBmXk6J8Y=; b=kCRGx/qbvGHvOIExprw0DDgkP+eOmEhGn+Aq946pDkC+5ITaDABqXsREVseqztX9bj imCTr/cd3ElcID1uCdt9MhKJkePYFyHBcGR0uYm9vtAGCVSYCIR5A8uTk6Tfh3DNfiyI n1q05AtsU523nCq8bRaRxpUdcQ2KlwJaA8k/YJftyN/tzQ4CnA1PWtLu6XIv1j0n45Jn BG6FxGm6e1n4PUG3G/6yNmsTnvHby5DuF2e7fcvay4kpaKC5XvH9+3fY6Vsf2NkDZVZ1 CQY5OlNqDLJxlS1t71GsB64Ah4WWZ7oBkAQ3q7NyGGrRBuUvlMJI/6WZ1+R0erHK7U0B k2KQ== X-Gm-Message-State: ANhLgQ10xC8+0hoqQtyHTo3rg3tLU5Lz5s6NqdtfvnMzIX3D2WC9qxyO Cav+OHza28a77rtmWqiMeM0= X-Google-Smtp-Source: ADFU+vs1u9SfcjF5RGIglTQpijbTZfS8yfBBuwrm2uVF6l/ojNbTblWiBQyIEcYPkcSSRfs4nBBHBQ== X-Received: by 2002:a1c:c906:: with SMTP id f6mr4622479wmb.16.1583341611386; Wed, 04 Mar 2020 09:06:51 -0800 (PST) Received: from dumbo ([83.137.6.114]) by smtp.gmail.com with ESMTPSA id o8sm4841231wmh.15.2020.03.04.09.06.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 09:06:50 -0800 (PST) Date: Wed, 4 Mar 2020 18:06:46 +0100 From: Domenico Andreoli To: "Darrick J. Wong" Cc: "Rafael J. Wysocki" , Linux PM , Linux Memory Management List , linux-fsdevel@vger.kernel.org, mkleinsoft@gmail.com, Christoph Hellwig , Andrew Morton , "Rafael J. Wysocki" , Len Brown , Pavel Machek Subject: [PATCH v2] hibernate: Allow uswsusp to write to swap Message-ID: <20200304170646.GA31552@dumbo> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Domenico Andreoli It turns out that there is one use case for programs being able to write to swap devices, and that is the userspace hibernation code. Quick fix: disable the S_SWAPFILE check if hibernation is configured. Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files") Reported-by: Domenico Andreoli Reported-by: Marian Klein Signed-off-by: Domenico Andreoli v2: - use hibernation_available() instead of IS_ENABLED(CONFIG_HIBERNATE) - make Fixes: point to the right commit Reviewed-by: Darrick J. Wong --- fs/block_dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) Index: b/fs/block_dev.c =================================================================== --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "internal.h" struct bdev_inode { @@ -2001,7 +2002,8 @@ ssize_t blkdev_write_iter(struct kiocb * if (bdev_read_only(I_BDEV(bd_inode))) return -EPERM; - if (IS_SWAPFILE(bd_inode)) + /* uswsusp needs write permission to the swap */ + if (IS_SWAPFILE(bd_inode) && !hibernation_available()) return -ETXTBSY; if (!iov_iter_count(from))