On Fri, Sep 04, 2020 at 12:05:30PM -0400, Jeff Layton wrote:
> After pre-creating a new inode, do an fscrypt prepare on it, fetch a
> new encryption context and then marshal that into the security context
> to be sent along with the RPC.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/ceph/crypto.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++
> fs/ceph/crypto.h | 8 ++++++
> fs/ceph/inode.c | 10 ++++++--
> fs/ceph/super.h | 3 +++
> 4 files changed, 82 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
> index 22a09d422b72..f4849f8b32df 100644
> --- a/fs/ceph/crypto.c
> +++ b/fs/ceph/crypto.c
> @@ -67,3 +67,66 @@ int ceph_fscrypt_set_ops(struct super_block *sb)
> }
> return 0;
> }
> +
> +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
> + struct ceph_acl_sec_ctx *as)
> +{
> + int ret, ctxsize;
> + size_t name_len;
> + char *name;
> + struct ceph_pagelist *pagelist = as->pagelist;
> + bool encrypted = false;
> +
> + ret = fscrypt_prepare_new_inode(dir, inode, &encrypted);
> + if (ret)
> + return ret;
> + if (!encrypted)
> + return 0;
> +
> + inode_set_flags(inode, S_ENCRYPTED, S_ENCRYPTED);
This is a new inode, so 'inode->i_flags |= S_ENCRYPTED' would be sufficient.
> +
> + /* No need to set context for dummy encryption */
> + if (fscrypt_get_dummy_context(inode->i_sb))
> + return 0;
This isn't correct. When test_dummy_encryption causes a new inode to be
automatically encrypted, the inode's encryption context is still supposed to be
saved to disk.
Also, when the filesystem is mounted with test_dummy_encryption, there may
already be existing encrypted directories that were created via the regular path
(not via test_dummy_encryption). Those should keep working as expected. That
likewise requires saving new encryption contexts to disk.
- Eric
