Re: [RFC PATCH V2 05/12] fs: remove unneeded IS_DAX() check

[Ira Weiny]

On Thu, Jan 16, 2020 at 10:38:07AM +0100, Jan Kara wrote:
> On Fri 10-01-20 11:29:35, ira.weiny@xxxxxxxxx wrote:
> > From: Ira Weiny <ira.weiny@xxxxxxxxx>
> > 
> > The IS_DAX() check in io_is_direct() causes a race between changing the
> > DAX mode and creating the iocb flags.
> > 
> > Remove the check because DAX now emulates the page cache API and
> > therefore it does not matter if the file mode is DAX or not when the
> > iocb flags are created.
> > 
> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> 
> The patch looks good to me. You can add:
> 
> Reviewed-by: Jan Kara <jack@xxxxxxx>

Thanks,
Ira

> 
> 								Honza
> 
> > ---
> >  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 d7584bcef5d3..e11989502eac 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -3365,7 +3365,7 @@ 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);
> >  }
> >  
> >  static inline bool vma_is_dax(struct vm_area_struct *vma)
> > -- 
> > 2.21.0
> > 
> -- 
> Jan Kara <jack@xxxxxxxx>
> SUSE Labs, CR