Re: [PATCH 09/11] ext4: Rip out DAX handling from direct IO path

[Jan Kara <jack@suse.cz>]

On Wed 16-11-16 10:13:35, Ross Zwisler wrote:
> On Tue, Nov 08, 2016 at 12:08:15PM +0100, Jan Kara wrote:
> > Reads and writes for DAX inodes should no longer end up in direct IO
> > code. Rip out the support and add a warning.
> > 
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> >  fs/ext4/inode.c | 49 +++++++++++++++----------------------------------
> >  1 file changed, 15 insertions(+), 34 deletions(-)
> > 
> > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> > index 4d71c7bc3524..72886e3bf0d3 100644
> > --- a/fs/ext4/inode.c
> > +++ b/fs/ext4/inode.c
> > @@ -3594,19 +3594,7 @@ static ssize_t ext4_direct_IO_write(struct kiocb *iocb, struct iov_iter *iter)
> >  	iocb->private = NULL;
> >  	if (overwrite)
> >  		get_block_func = ext4_dio_get_block_overwrite;
> > -	else if (IS_DAX(inode)) {
> > -		/*
> > -		 * We can avoid zeroing for aligned DAX writes beyond EOF. Other
> > -		 * writes need zeroing either because they can race with page
> > -		 * faults or because they use partial blocks.
> > -		 */
> > -		if (round_down(offset, 1<<inode->i_blkbits) >= inode->i_size &&
> > -		    ext4_aligned_io(inode, offset, count))
> > -			get_block_func = ext4_dio_get_block;
> > -		else
> > -			get_block_func = ext4_dax_get_block;
> 
> This was the last use of ext4_dax_get_block(), so that function can safely be
> removed.  I can do that in a separate patch, if you don't want to pull it into
> this set.

Good point. Added removal to this patch.

> Otherwise this looks correct to me.
> 
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

Thanks.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR