Re: [PATCH RFC 2/8] fs/ext4: Disallow verity if inode is DAX

Jan Kara
2020-04-15T12:06:44Z

On Mon 13-04-20 21:00:24, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> Verity and DAX are incompatible. Changing the DAX mode due to a verity
> flag change is wrong without a corresponding address_space_operations
> update.
>
> Make the 2 options mutually exclusive by returning an error if DAX was
> set first.
>
> (Setting DAX is already disabled if Verity is set first.)
>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/ext4/verity.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
> index dc5ec724d889..ce3f9a198d3b 100644
> --- a/fs/ext4/verity.c
> +++ b/fs/ext4/verity.c
> @@ -113,6 +113,9 @@ static int ext4_begin_enable_verity(struct file *filp)
> handle_t *handle;
> int err;
>
> + if (WARN_ON_ONCE(IS_DAX(inode)))
> + return -EINVAL;
> +
> if (ext4_verity_in_progress(inode))
> return -EBUSY;
>
> --
> 2.25.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR