Re: [PATCH 5/5] vfs: only allow FSSETXATTR to set DAX flag on files and dirs

[Jan Kara]

On Fri 28-06-19 11:34:31,  Darrick J. Wong  wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> 
> The DAX flag only applies to files and directories, so don't let it get
> set for other types of files.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/inode.c |    8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> 
> diff --git a/fs/inode.c b/fs/inode.c
> index 670d5408d022..f08711b34341 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -2259,6 +2259,14 @@ int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa,
>  	    !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
>  		return -EINVAL;
>  
> +	/*
> +	 * It is only valid to set the DAX flag on regular files and
> +	 * directories on filesystems.
> +	 */
> +	if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
> +	    !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
> +		return -EINVAL;
> +
>  	/* Extent size hints of zero turn off the flags. */
>  	if (fa->fsx_extsize == 0)
>  		fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
> 
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR