Re: [PATCH] ceph: set DCACHE_NOKEY_NAME in atomic open

[Xiubo Li <xiubli@redhat.com>]

On 3/29/22 4:33 AM, Jeff Layton wrote:
> Atomic open can act as a lookup if handed a dentry that is negative on
> the MDS. Ensure that we set DCACHE_NOKEY_NAME on the dentry in
> atomic_open, if we don't have the key for the parent. Otherwise, we can
> end up validating the dentry inappropriately if someone later adds a
> key.
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>   fs/ceph/file.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> Another patch for the fscrypt series.
>
> A much less heavy-handed fix for generic/580 and generic/593. I'll
> probably fold this into an earlier patch in the series since it appears
> to be a straightforward bug.
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index eb04dc8f1f93..5072570c2203 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -765,8 +765,14 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
>   	req->r_args.open.mask = cpu_to_le32(mask);
>   	req->r_parent = dir;
>   	ihold(dir);
> -	if (IS_ENCRYPTED(dir))
> +	if (IS_ENCRYPTED(dir)) {
>   		set_bit(CEPH_MDS_R_FSCRYPT_FILE, &req->r_req_flags);
> +		if (!fscrypt_has_encryption_key(dir)) {
> +			spin_lock(&dentry->d_lock);
> +			dentry->d_flags |= DCACHE_NOKEY_NAME;
> +			spin_unlock(&dentry->d_lock);
> +		}
> +	}
>   
>   	if (flags & O_CREAT) {
>   		struct ceph_file_layout lo;
Reviewed-by: Xiubo Li <xiubli@redhat.com>