From: Luis Henriques <lhenriques@suse.de>
To: Jeff Layton <jlayton@kernel.org>
Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [fscrypt][RFC PATCH] ceph: don't allow changing layout on encrypted files/directories
Date: Fri, 13 Aug 2021 14:03:04 +0100 [thread overview]
Message-ID: <YRZtiL+qo95vK0Nf@suse.de> (raw)
Encryption is currently only supported on files/directories with layouts
where stripe_count=1. Forbid changing layouts when encryption is involved.
Signed-off-by: Luis Henriques <lhenriques@suse.de>
---
Hi!
While continuing looking into fscrypt, I realized we're not yet forbidding
different layouts on encrypted files. This patch tries to do just that.
Regarding the setxattr, I've also made a change [1] to the MDS code so that it
also prevents layouts to be changed. This should make the changes to
ceph_sync_setxattr() redundant, but in practice it doesn't because if we encrypt
a directory and immediately after that we change that directory layout, the MDS
wouldn't yet have received the fscrypt_auth for that inode. So... yeah, an
alternative would be to propagate the fscrypt context immediately after
encrypting a directory.
[1] https://github.com/luis-henrix/ceph/commit/601488ae798ecfa5ec81677d1ced02f7dd42aa10
Cheers,
--
Luis
fs/ceph/ioctl.c | 4 ++++
fs/ceph/xattr.c | 6 ++++++
2 files changed, 10 insertions(+)
diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index 477ecc667aee..42abfc564301 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -294,6 +294,10 @@ static long ceph_set_encryption_policy(struct file *file, unsigned long arg)
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
+ /* encrypted directories can't have striped layout */
+ if (ci->i_layout.stripe_count > 1)
+ return -EOPNOTSUPP;
+
ret = vet_mds_for_fscrypt(file);
if (ret)
return ret;
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index b175b3029dc0..7921cb34900c 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1051,6 +1051,12 @@ static int ceph_sync_setxattr(struct inode *inode, const char *name,
int op = CEPH_MDS_OP_SETXATTR;
int err;
+ /* encrypted directories/files can't have their layout changed */
+ if (IS_ENCRYPTED(inode) &&
+ (!strncmp(name, "ceph.file.layout", 16) ||
+ !strncmp(name, "ceph.dir.layout", 15)))
+ return -EOPNOTSUPP;
+
if (size > 0) {
/* copy value into pagelist */
pagelist = ceph_pagelist_alloc(GFP_NOFS);
Cheers,
--
Luís
next reply other threads:[~2021-08-13 13:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-13 13:03 Luis Henriques [this message]
2021-08-16 12:44 ` [fscrypt][RFC PATCH] ceph: don't allow changing layout on encrypted files/directories Jeff Layton
2021-08-16 13:43 ` Luis Henriques
2021-08-16 14:01 ` Jeff Layton
2021-08-16 16:03 ` Luis Henriques
2021-08-16 17:52 ` Jeff Layton
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