Re: [PATCH v2 20/20] btrfs: implement fscrypt ioctls

[David Sterba <dsterba@suse.cz>]

On Mon, Sep 05, 2022 at 08:35:35PM -0400, Sweet Tea Dorminy wrote:
> From: Omar Sandoval <osandov@osandov.com>
> 
> These ioctls allow encryption to be set up.
> 
> Signed-off-by: Omar Sandoval <osandov@osandov.com>
> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
> ---
>  fs/btrfs/ioctl.c | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 708e514aca25..ea1c14b26206 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -5457,6 +5457,34 @@ long btrfs_ioctl(struct file *file, unsigned int
>  		return btrfs_ioctl_get_fslabel(fs_info, argp);
>  	case FS_IOC_SETFSLABEL:
>  		return btrfs_ioctl_set_fslabel(file, argp);
> +	case FS_IOC_SET_ENCRYPTION_POLICY: {
> +		if (!IS_ENABLED(CONFIG_FS_ENCRYPTION))
> +			return -EOPNOTSUPP;
> +		if (sb_rdonly(fs_info->sb))
> +			return -EROFS;
> +		/*
> +		 *  If we crash before we commit, nothing encrypted could have
> +		 * been written so it doesn't matter whether the encrypted
> +		 * state persists.
> +		 */
> +		btrfs_set_fs_incompat(fs_info, FSCRYPT);
> +		return fscrypt_ioctl_set_policy(file, (const void __user *)arg);
> +	}
> +	case FS_IOC_GET_ENCRYPTION_POLICY:
> +		return fscrypt_ioctl_get_policy(file, (void __user *)arg);
> +	case FS_IOC_GET_ENCRYPTION_POLICY_EX:
> +		return fscrypt_ioctl_get_policy_ex(file, (void __user *)arg);
> +	case FS_IOC_ADD_ENCRYPTION_KEY:
> +		return fscrypt_ioctl_add_key(file, (void __user *)arg);
> +	case FS_IOC_REMOVE_ENCRYPTION_KEY:
> +		return fscrypt_ioctl_remove_key(file, (void __user *)arg);
> +	case FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS:
> +		return fscrypt_ioctl_remove_key_all_users(file,
> +							  (void __user *)arg);
> +	case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
> +		return fscrypt_ioctl_get_key_status(file, (void __user *)arg);
> +	case FS_IOC_GET_ENCRYPTION_NONCE:
> +		return fscrypt_ioctl_get_nonce(file, (void __user *)arg);

I've looked what ext4 does for the ioctls and there's a check before
each case if the feature is supported, do we need something like that as
well?

>  	case FITRIM:
>  		return btrfs_ioctl_fitrim(fs_info, argp);
>  	case BTRFS_IOC_SNAP_CREATE:
> -- 
> 2.35.1