Re: [PATCH V4 03/13] fs: Remove unneeded IS_DAX() check

From: Christoph Hellwig
Date: Fri Feb 21 2020 - 12:42:22 EST


On Thu, Feb 20, 2020 at 04:41:24PM -0800, ira.weiny@xxxxxxxxx wrote:
> From: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> Remove the check because DAX now has it's own read/write methods and
> file systems which support DAX check IS_DAX() prior to IOCB_DIRECT on
> their own. Therefore, it does not matter if the file state is DAX when
> the iocb flags are created.
>
> Reviewed-by: Jan Kara <jack@xxxxxxx>
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> ---
> Changes from v3:
> Reword commit message.
> Reordered to be a 'pre-cleanup' patch
> ---
> include/linux/fs.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 3cd4fe6b845e..63d1e533a07d 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -3388,7 +3388,7 @@ extern int file_update_time(struct file *file);
>
> static inline bool io_is_direct(struct file *filp)
> {
> - return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);
> + return (filp->f_flags & O_DIRECT);

Please just kill io_is_direct entirely.