From patchwork Thu Aug 15 16:05:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 11095961 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D032813A0 for ; Thu, 15 Aug 2019 16:06:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BF4ED28869 for ; Thu, 15 Aug 2019 16:06:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B3938288E6; Thu, 15 Aug 2019 16:06:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4501B288C3 for ; Thu, 15 Aug 2019 16:06:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EEA6B6B02B5; Thu, 15 Aug 2019 12:06:02 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id E76AB6B02B7; Thu, 15 Aug 2019 12:06:02 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D4A736B02B5; Thu, 15 Aug 2019 12:06:02 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0107.hostedemail.com [216.40.44.107]) by kanga.kvack.org (Postfix) with ESMTP id ABC286B02B5 for ; Thu, 15 Aug 2019 12:06:02 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 64859181AC9B6 for ; Thu, 15 Aug 2019 16:06:02 +0000 (UTC) X-FDA: 75825138564.06.fruit55_178b7f040c650 X-HE-Tag: fruit55_178b7f040c650 X-Filterd-Recvd-Size: 6420 Received: from aserp2120.oracle.com (aserp2120.oracle.com [141.146.126.78]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Aug 2019 16:06:01 +0000 (UTC) Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7FG3t30003048; Thu, 15 Aug 2019 16:05:53 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-2019-08-05; bh=fGMpErgCA/O5M9vyBFLeT14i3Vu31Za+KYREJqkVJ/U=; b=cHB+qxHp9WxMM2txiWT1G6ixmPnpbAvSckZYGJB52VFTP8AzGOFCYoMwMsLM11+Inwyv lIYMdRSYhpDpCkmI/arv9j1G3prLRfMXufbsY+DuG8v5i6EvZwUwLbtTeuqjHpEXermQ tPrkFDh2onQ3ZDiRbZ5o/pzG0XvBRVTwYUnGeRChFXsEov6EB96DwWRYyt6IYP5JNYif OHyCXuGQCWpOCWcN7d7Hkc0n1k7XPIkX4mYuJmMEb69EHvCJRMUcqhsKw+fuiVxMmJGq Bb7DWejbd0+wXSDlLwWbGZpSwbDnbIKU+icMP/4QG+7Hq4sHN1baanZtY00F6yVaGBp3 jw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 2u9nvpkp3c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 15 Aug 2019 16:05:53 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7FG31ul107851; Thu, 15 Aug 2019 16:05:52 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3030.oracle.com with ESMTP id 2ucmwjuwmq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 15 Aug 2019 16:05:52 +0000 Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x7FG5pJX002636; Thu, 15 Aug 2019 16:05:51 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 15 Aug 2019 09:05:50 -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: Thu, 15 Aug 2019 09:05:47 -0700 Message-ID: <156588514761.111054.15427341787826850860.stgit@magnolia> In-Reply-To: <156588514105.111054.13645634739408399209.stgit@magnolia> References: <156588514105.111054.13645634739408399209.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9350 signatures=668684 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=8.0.1-1906280000 definitions=main-1908150157 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9350 signatures=668684 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=8.0.1-1906280000 definitions=main-1908150158 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: X-Virus-Scanned: ClamAV using ClamSMTP 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 Reviewed-by: Christoph Hellwig --- mm/swapfile.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 0789a762ce2f..a53b7c49b40e 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2368,9 +2368,8 @@ 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 @@ -2661,13 +2660,14 @@ 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); /* @@ -2890,11 +2890,11 @@ 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; } @@ -3295,8 +3295,7 @@ 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: @@ -3318,7 +3317,7 @@ 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; } @@ -3331,7 +3330,7 @@ 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();