From patchwork Thu Sep 26 06:40:12 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hui Wang X-Patchwork-Id: 278124 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 1A16A2C00B9 for ; Thu, 26 Sep 2013 16:41:25 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1VP5GJ-0001ME-QX; Thu, 26 Sep 2013 06:41:19 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1VP5Fq-00019K-LM for kernel-team@lists.ubuntu.com; Thu, 26 Sep 2013 06:40:50 +0000 Received: from [116.213.97.190] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1VP5Fp-0005YX-SD for kernel-team@lists.ubuntu.com; Thu, 26 Sep 2013 06:40:50 +0000 From: Hui Wang To: kernel-team@lists.ubuntu.com Subject: [Saucy PATCH 1/3] isofs: Refuse RW mount of the filesystem instead of making it RO Date: Thu, 26 Sep 2013 14:40:12 +0800 Message-Id: <1380177614-22952-7-git-send-email-hui.wang@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1380177614-22952-1-git-send-email-hui.wang@canonical.com> References: <1380177614-22952-1-git-send-email-hui.wang@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com From: Jan Kara BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1228751 Refuse RW mount of isofs filesystem. So far we just silently changed it to RO mount but when the media is writeable, block layer won't notice this change and thus will think device is used RW and will block eject button of the drive. That is unexpected by users because for non-writeable media eject button works just fine. Userspace mount(8) command handles this just fine and retries mounting with MS_RDONLY set so userspace shouldn't see any regression. Plus any tool mounting isofs is likely confronted with the case of read-only media where block layer already refuses to mount the filesystem without MS_RDONLY set so our behavior shouldn't be anything new for it. Reported-by: Hui Wang Signed-off-by: Jan Kara (cherry picked from commit 17b7f7cf58926844e1dd40f5eb5348d481deca6a) Signed-off-by: Hui Wang --- After apply these 3 patches to saucy kernel, i did a building test, the test passed. Then i used a dvd-rw isofs disc and cd-rw udf ro disc to test, they worked well and the eject button also work well. fs/isofs/inode.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c index c348d6d..e5d408a 100644 --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -117,8 +117,8 @@ static void destroy_inodecache(void) static int isofs_remount(struct super_block *sb, int *flags, char *data) { - /* we probably want a lot more here */ - *flags |= MS_RDONLY; + if (!(*flags & MS_RDONLY)) + return -EROFS; return 0; } @@ -763,15 +763,6 @@ root_found: */ s->s_maxbytes = 0x80000000000LL; - /* - * The CDROM is read-only, has no nodes (devices) on it, and since - * all of the files appear to be owned by root, we really do not want - * to allow suid. (suid or devices will not show up unless we have - * Rock Ridge extensions) - */ - - s->s_flags |= MS_RDONLY /* | MS_NODEV | MS_NOSUID */; - /* Set this for reference. Its not currently used except on write which we don't have .. */ @@ -1530,6 +1521,9 @@ struct inode *isofs_iget(struct super_block *sb, static struct dentry *isofs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { + /* We don't support read-write mounts */ + if (!(flags & MS_RDONLY)) + return ERR_PTR(-EACCES); return mount_bdev(fs_type, flags, dev_name, data, isofs_fill_super); }