Re: [PATCH 1/5] ext4: introduce direct IO read code path using iomap infrastructure

[Matthew Wilcox <willy@xxxxxxxxxxxxx>]

On Mon, Aug 12, 2019 at 10:18:35AM -0700, Christoph Hellwig wrote:
> >  		return -EIO;
> >  
> >  	if (!iov_iter_count(to))
> >  		return 0; /* skip atime */
> >  
> >  #ifdef CONFIG_FS_DAX
> > -	if (IS_DAX(file_inode(iocb->ki_filp)))
> > +	if (IS_DAX(inode))
> >  		return ext4_dax_read_iter(iocb, to);
> >  #endif
> 
> Same here.

It doesn't even need IS_ENABLED.

include/linux/fs.h:#define IS_DAX(inode)                ((inode)->i_flags & S_DAX)

#ifdef CONFIG_FS_DAX
#define S_DAX           8192    /* Direct Access, avoiding the page cache */
#else
#define S_DAX           0       /* Make all the DAX code disappear */
#endif