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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 CB271C4321A for ; Fri, 28 Jun 2019 18:35:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0D9620828 for ; Fri, 28 Jun 2019 18:35:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="W7BT12TU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726716AbfF1Sfb (ORCPT ); Fri, 28 Jun 2019 14:35:31 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:39118 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726723AbfF1Sf3 (ORCPT ); Fri, 28 Jun 2019 14:35:29 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5SIYGGJ114587; Fri, 28 Jun 2019 18:35:20 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : from : to : cc : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=o7DgJUcGo9xVHV7BN6dTCgC24ypKZRenCunIj09I43o=; b=W7BT12TUQkRJc9zRIeLhgn2TNRvJwTMiDY2FRc1JZiV7LY8SgJhVvHyo87i11W9DBPa0 pdCDemTe0pkBz32X7/AXbMRQmMr+omDeTw82InHU3ID+hot/1bDViavs0AMQpu2xalrc /Mf0xks9kzi7JYAlYEHg/Hqdu98lhi5JaWG/YgM7H71rO7WVKKkOxQZ/7blOdeZgl/pr 9FUAQNbeoiYEsIiEjutUGPEdZXAyInYOFdWCkcqe2teTVjDL3kR2iF0Xyo34VLK9uzF6 2IvnN5yBkZH/gKUyJsWEo+UmyOPG6dvxFFdCOvc2rndw6PvnRWiSKpHisobdXsZiNLnJ MA== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 2t9cyqxym1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 28 Jun 2019 18:35:20 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5SIYqFH152196; Fri, 28 Jun 2019 18:35:19 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 2t9p6w238c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 28 Jun 2019 18:35:19 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x5SIZJNC027332; Fri, 28 Jun 2019 18:35:19 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 28 Jun 2019 11:35:19 -0700 Subject: [PATCH 1/2] mm: set S_SWAPFILE on blockdev swap devices From: "Darrick J. Wong" To: hch@infradead.org, akpm@linux-foundation.org, tytso@mit.edu, viro@zeniv.linux.org.uk, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Date: Fri, 28 Jun 2019 11:35:17 -0700 Message-ID: <156174691783.1557844.3238867236650883424.stgit@magnolia> In-Reply-To: <156174691124.1557844.14293659081769020256.stgit@magnolia> References: <156174691124.1557844.14293659081769020256.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9302 signatures=668688 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906280209 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9302 signatures=668688 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906280210 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Darrick J. Wong Set S_SWAPFILE on block device inodes so that they have the same protections as a swap flie. Signed-off-by: Darrick J. Wong --- mm/swapfile.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 596ac98051c5..fa4edd0cca3a 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2284,9 +2284,8 @@ EXPORT_SYMBOL_GPL(add_swap_extent); * requirements, they are simply tossed out - we will never use those blocks * for swapping. * - * For S_ISREG swapfiles we set S_SWAPFILE across the life of the swapon. This - * prevents root from shooting her foot off by ftruncating an in-use swapfile, - * which will scribble on the fs. + * For all swap devices we set S_SWAPFILE across the life of the swapon. This + * prevents users from writing to the swap device, which will corrupt memory. * * The amount of disk space which a single swap extent represents varies. * Typically it is in the 1-4 megabyte range. So we can have hundreds of @@ -2551,13 +2550,14 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) inode = mapping->host; if (S_ISBLK(inode->i_mode)) { struct block_device *bdev = I_BDEV(inode); + set_blocksize(bdev, old_block_size); blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); - } else { - inode_lock(inode); - inode->i_flags &= ~S_SWAPFILE; - inode_unlock(inode); } + + inode_lock(inode); + inode->i_flags &= ~S_SWAPFILE; + inode_unlock(inode); filp_close(swap_file, NULL); /* @@ -2780,11 +2780,11 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode) p->flags |= SWP_BLKDEV; } else if (S_ISREG(inode->i_mode)) { p->bdev = inode->i_sb->s_bdev; - inode_lock(inode); - if (IS_SWAPFILE(inode)) - return -EBUSY; - } else - return -EINVAL; + } + + inode_lock(inode); + if (IS_SWAPFILE(inode)) + return -EBUSY; return 0; } @@ -3185,8 +3185,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) atomic_inc(&proc_poll_event); wake_up_interruptible(&proc_poll_wait); - if (S_ISREG(inode->i_mode)) - inode->i_flags |= S_SWAPFILE; + inode->i_flags |= S_SWAPFILE; error = 0; goto out; bad_swap: @@ -3208,7 +3207,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (inced_nr_rotate_swap) atomic_dec(&nr_rotate_swap); if (swap_file) { - if (inode && S_ISREG(inode->i_mode)) { + if (inode) { inode_unlock(inode); inode = NULL; } @@ -3221,7 +3220,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) } if (name) putname(name); - if (inode && S_ISREG(inode->i_mode)) + if (inode) inode_unlock(inode); if (!error) enable_swap_slots_cache();