From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Brauner Subject: [PATCH 3/3] ecryptfs: extend ro check to private mount Date: Fri, 9 Apr 2021 18:24:22 +0200 Message-ID: <20210409162422.1326565-4-brauner@kernel.org> References: <20210409162422.1326565-1-brauner@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from mail.kernel.org ([198.145.29.99]:34238 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233674AbhDIQ0S (ORCPT ); Fri, 9 Apr 2021 12:26:18 -0400 In-Reply-To: <20210409162422.1326565-1-brauner@kernel.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: Tyler Hicks , ecryptfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, Amir Goldstein , Christian Brauner From: Christian Brauner So far ecryptfs only verified that the superblock wasn't read-only but didn't check whether the mount was. This made sense when we did not use a private mount because the read-only state could change at any point. Now that we have a private mount and mount properties can't change behind our back extend the read-only check to include the vfsmount. The __mnt_is_readonly() helper will check both the mount and the superblock. Note that before we checked root->d_sb and now we check mnt->mnt_sb but since we have a matching pair here this is only syntactical change, not a semantic one. Overlayfs and cachefiles have been changed to check this as well. Cc: Amir Goldstein Cc: Tyler Hicks Cc: ecryptfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner --- fs/ecryptfs/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 9dcf9a0dd37b..cdf37d856c62 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -569,7 +569,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags * 1) The lower mount is ro * 2) The ecryptfs_encrypted_view mount option is specified */ - if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) + if (__mnt_is_readonly(mnt) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) s->s_flags |= SB_RDONLY; s->s_maxbytes = path.dentry->d_sb->s_maxbytes; -- 2.27.0